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GU/Ob/Gyn

Chaudry S. University of Washington, Seattle, WA

Address correspondence to S. Chaudry (sidhartha.chaudry{at}gmail.com)

Background: Carcinoma of the cervix is the twelfth most common form of cancer in women in North America. In the United States alone there were more than 13,000 new cases of invasive cervical carcinoma detected in 2002 with more than 4,100 cervical cancer related deaths. Clinical FIGO staging may differ from surgical staging from 17 to 32% for a stage 1B tumor to up to 95% for a stage 3B tumor. Primary endocervical lesions may not be visualized and evaluated satisfactorily by clinical methods. MR has an accuracy rate of up to 95% in demonstrating the tumor.

Key Issues: Cervical carcinoma typically arises at the junction of squamous ectocervical and the columnar endocervical epithelium. The lesions in younger women are polypoid and arise from the ectocervix (portiovaginalis). Older women with atrophied cervices have ascent of the squamocolumnar junction into the endocervical region. Carcinomas in this cohort arise in the supravaginal part of the cervix and have a higher incidence of parametrial invasion. Technique: Oblique axial (short axis) and sagittal fast spin echo T2-weighted images are obtained using a phased-array pelvic multicoil. Typical parameters are TR/TE/ETL: 4000/102/16, 20–24 cm FOV, matrix 512 x 512, 4 signal averages, 4/1 mm slice thickness. Dynamic fat-suppressed spoiled gradient echo (TR/TE 150–250/4.2 20–24 cm FOV, matrix 256 x 192, 1 signal average, breath-hold) sequences are obtained pre- and post-gadolinium at 0.1 mM/kg, injected at 2 ml per second. Value of MRI in staging: Important prognostic factors for cervical cancer are stromal invasion, tumor volume and regional lymph node metastasis. The disruption of low signal intensity cervical ring by higher signal tumor on T2-weighted images is suggestive of full thickness stromal invasion. Parametrial invasion is associated with higher incidence of hematogenous and lymph node metastases, therefore rendering these patients inoperable. MRI is up to 95% accurate in identifying operative candidates (stage 1 and 2A) compared with 76% for CT.

Format: This exhibit will be presented in a didactic format highlighting clinical issues, technical factors and stage-wise key imaging findings of cervical cancer.

Teaching Points: The viewer at the end of this exhibit: 1. Will have orientation to normal MRI anatomy of the structure of the cervix. 2. Know how to protocol an MRI dedicated toward cervical cancer staging. 3. Learn the MR appearance of different stages of cervical cancer.

E218. MRI Imaging of Cervical and Endometrial Neoplasms

Peungjesada S.; Balachandran A.; Iyer R.; Bhosale P. MD Anderson Cancer Research Center, Houston, TX

Address correspondence to S. Peungjesada (Silanath.Peungjesada{at}di.mdacc.tmc.edu)

Background: Magnetic resonance imaging (MRI) depicts the morphologic details of the female pelvis and helps in assessment of both benign and malignant uterine and cervical masses. Endometrial cancer is the most common gynecologic malignancy and cervical cancer is the third most common malignancy of the female genital tract. Although current clinical and surgical staging with the International Federation of Gynecology and Obstetrics (FIGO) is universally accepted, MRI is now an integral part of and is widely accepted in staging of endometrial and the cervical cancer. It has a great impact on the treatment planning, survival and prognosis. While interpreting MR images, it is important for a radiologist to recognize the imaging characteristics of endometrial and cervical cancer and be able to furnish a definitive diagnosis.

Key Issues: We will discuss the importance of 3D dynamic gradient echo sagittal sequences, along with T2-weighted sagittal and axial sequences for correct analyses and interpretation of cervical and endometrial malignancy. This exhibit will discuss the epidemiology, normal anatomy, imaging findings and staging of cervical and endometrial cancer.

Format: This will be an interactive self-learning electronic exhibit, where the attendee will be able choose the type of cancer, the staging, imaging characteristics, epidemiology etc. based on her/his interest

Teaching Points: The attendee will become familiar with clinical presentations, epidemiology, normal MRI anatomy, MRI findings and dynamic enhancement characteristics of the endometrial and cervical carcinoma.

E219. Imaging Spectrum of Endometriosis: Pictorial Review

Jung N.¹; Byun J.²; Rha S.²; Oh S.²; Lee Y.²; Jung S.³; Lee J.³ 1. Holy Family Hospital, Catholic University of Korea, Buchon-si, Kyungko-do, South Korea; 2. Kangnam St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea; 3. St. Mary's Hospital, Catholic University of Korea, Seoul, South Korea

Address correspondence to N. Jung (healmind{at}catholic.ac.kr)

Background: Endometriosis, an important gynecological disorder of reproductive women, is defined as presence of functional endometrial glands and stroma in location outside the uterus. The clinical manifestation of endometriosis varies from microscopic implants to large cysts. Endometriosis can be seen as peritoneal endometrial implants (solid endometrial tissues), endometriomas (endometrial cyst) or adhesion on imaging. Endometriosis commonly affects the ovaries and pelvic organ such as cul-de-sac, uterine ligaments, pelvic reflection and less frequently the gastrointestinal tract, urinary tract, and soft tissues.

Key Issues: Although the gold standard in diagnosis and staging of endometriosis is laparoscopy, preoperative imaging evaluation of endometriosis is widely performed and plays an important role in assessing the presence and extent of endometriosis. There is a broad spectrum of imaging findings of endometriosis, including typical imaging findings of endometrioma and atypical imaging findings of peritoneal implants and adhesion mimicking malignancy. The sensitivity and specificity of ultrasonography and computed tomography are limited; in contrast, those of magnetic resonance imaging are greater in diagnosing endometrial cyst and relatively high in demonstrating endometrial implants.

Format: This exhibition is didactic for not only genitourinary radiologists but also radiologists in other specialties and residents. First, we will review the theories according to the histopathogenesis of endometriosis and the laparoscopy-based staging system. We will compare the advantage and limitation of ultrasonography, CT, and MR imaging techniques in diagnosing endometriosis and review the broad imaging spectrum of endometriosis. We will also demonstrate the imaging findings of endometriosis at the specific sites of the lesions from ovary to cutaneous tissue. Finally, we will illustrate cases of endometriosis-related complication and malignancy.

Teaching Points: 1. To illustrate a broad spectrum of imaging findings of endometriosis. 2. To demonstrate atypical imaging findings of endometriosis with pathologic correlation. 3. To demonstrate strength and limitation of each imaging modalities in diagnosing endometriosis.

E220. Sonohysterography—An Illustrative Primer in the Evaluation of the Endometrium

Kruger A. Y.; Ghoshhajra B.; Beasley H. Western Pennsylvania Hospital, Pittsburgh, PA

Address correspondence to A. Kruger (ifdg442{at}yahoo.com)

Background: The purpose of this exhibit is: 1. To review the technique of performing a sonohysterogram. 2. To review the normal anatomic findings when performing sonohysterography. 3. To review the abnormal sonohysterogram findings associated with common causes of vaginal bleeding and a thickened endometrium.

Key Issues: Review of the imaging findings on sonohysterogram of normal anatomy and the abnormal endometrial causes of vaginal bleeding and a thickened endometrium.

Format: The format of this exhibit will be didactic and it will be organized by pathology.

Teaching Points: After completing this exhibit, the viewer will understand how to perform a sonohysterogram and will be able to recognize the normal and abnormal findings commonly seen during sonohysterography.

E221. Imaging Spectrum of Ovarian and Extraovarian Endometriosis with Pathologic Correlation

Prasad S. R.²; Menias C. O.¹; Huettner P.³; Surabhi V.²; Narra V. R.¹; Chintapalli K. N.² 1. Mallinckrodt Institute of Radiology, St. Louis, MO; 2. University of Texas HSC at San Antonio, San Antonio, TX; 3. Washington University in St. Louis, St. Louis, MO

Address correspondence to S. Prasad (prasads{at}uthscsa.edu)

Purpose/Aim of the Exhibit: 1. To review recent advances in cytogenetics and pathogenesis of ovarian and extraovarian endometriosis. 2. To discuss the imaging spectrum of ovarian and extraovarian endometriosis including endometriosis-associated carcinomas 3. To correlate imaging findings with gross and histopathology.

Content Organization: 1. Histological taxonomy of endometriosis. 2. Typical and atypical endometriosis: the bad and the ugly. 3. Ovarian and extraovarian endometriosis: cytogenetics and pathogenesis. 4. Characteristic epidemiology, clinical manifestations of endometriosis. 5. Ovarian and extraovarian endometriosis: imaging spectrum with pathological correlation. 6. Endometriosis associated ovarian and extraovarian carcinomas.

Format: Didactic by imaging modality with pathologic correlation.

Conclusion/Summary: Endometriosis is a nonneoplastic proliferative condition that results from a complex interplay of genetic and hormonal factors. Although the ovary is the most common target site for endometriosis, it can occur at a multitude of extraovarian sites with characteristic clinical findings. Recent advances in cytogenetics permit better understanding of pathogenesis and development of molecular therapeutics. Ovarian and extraovarian endometriosis are considered premalignant conditions because of their tendency to induce cancers. Atypical endometriosis undergoes malignant change to low-grade endometrioid and clear cell carcinomas in the target organs.

E222. CT and MR Imaging Findings of Clear Cell Carcinoma of the Ovary

Lee Y.¹; Jung G.¹; Oh S.¹; Jung S.¹; Rha S.¹; Byun J.¹; Kim K.²; Kim B.³ 1. Kangnam St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea; 2. Korea Cancer Center Hospital, Seoul, South Korea; 3. Samsung Medical Center, Seoul, South Korea

Address correspondence to Y. Lee (yjleerad{at}catholic.ac.kr)

Objective: The purpose of this study is to investigate the CT and MR findings of ovarian clear cell carcinoma.

Materials and Methods: CT and MR imaging of 33 pathologically proven ovarian clear cell carcinoma (CCC) in 28 patients were retrospectively reviewed. The tumors were analyzed for size, bilaterality, presence of ascites, margin, morphology, and pattern of contrast enhancement.

Results: The mean size of the tumors was 11.8 cm. Five patients had bilateral tumors (19%). 12 patients had pelvic ascites and 4 patients had pelvic and perihepatic ascites (57%). All tumors showed well defined smooth margins. Six (18%) showed unilocular cystic type with round or papillary solid portion. Ten (30%) showed oligolocular cystic type (less than 5 locules) with round or papillary solid portion. 11 (33%) showed multilocular cystic type with solid portion. Four of these 11 tumors were composed of eccentrical smaller multiseptated cyst within the outer larger cyst. Five (15%) showed mixed solid and cystic type in which solid components were more than half of the tumor. One (3%) showed oligolocular cystic type without solid portion. 11 of 23 tumors on MR (48%) showed T1 high signal intensity suggesting hemorrhagic or endometrial cyst. 29 of 32 tumors with solid portion (91%) showed well homogeneous contrast enhancement.

Conclusion: The most common finding of ovarian CCC was unilocular cystic tumor with round or papillary solid component. When there is eccentrically located, smaller multiseptated cyst within the outer larger cyst, ovarian CCC should be included in the differential diagnosis.

E223. Comparison of 18F-FDG PET/CT and CT or MRI for the Preoperative Staging of Ovarian Cancer

Jung G.¹; Lee Y.¹; Oh S.¹; Byun J.¹; Ryu I.²; Kim S.²; Chung S.² 1. Diagnostic Radiology, Kangnam St. Mary's Hospital, Seoul, South Korea; 2. Nuclear Medicine, Kangnam St. Mary's hospital, Seoul, South Korea

Address correspondence to G. Jung (i902{at}catholic.ac.kr)

Objective: To compare the diagnostic performance of 18F-FDG PET/CT with CT or MRI for the preoperative staging of ovarian cancer.

Materials and Methods: 28 patients (mean age, 45 years; range, 15–67 years) with surgically confirmed to malignant ovarian carcinoma (mean size, 11.2 cm; range 4–30 cm) underwent both preoperative 18F-FDG PET/CT and CT or MRI (CT on 20 patients, and MR on 10 patients). 18F-PET/CT and CT or MR images were evaluated separately and imaging results were compared with pathologic and operative findings. We analyzed the image findings focusing on the following characteristics: 18F-FDG uptake or enhancing solid portion, pelvic lymph node metastasis, para-aortic lymph node metastasis, distant metastasis, peritoneal carcinomatosis and FIGO staging.

Results: Staging revealed stage I disease in eleven patients (IA, n = 9; IC, n = 3), stage III in twelve (IIIA, n = 2, IIIC, n = 12), stage IV in two, according to the FIGO criteria. 6 tumors (21%) had no abnormal uptake on 18F-FDG PET/CT and one tumor (4%) had no evidence of enhancing solid portion on CT or MRI. All of those tumors are stage I disease. 18-FDG PET/CT staging correlated with postoperative staging in 22 of 28 patients (79%) and CT or MRI staging also correlated in 22 of 28 patients (79%).

Conclusion: In patients with malignant ovarian cancer, 18F-FDG PET/CT has no additional benefit to accurate diagnosis of preoperative staging, compared to CT or MRI.

E224. Beyond Uterus and Ovaries: MRI of the Deep Female Pelvis

Bridges M. D.; Nasir S. M. Mayo Clinic, Jacksonville, FL

Address correspondence to M. Bridges (Bridges.Mellena{at}mayo.edu)

Background: The utility of MR imaging is well established for the evaluation of the neurological and musculoskeletal systems. More recently, with the rapidly increasing sophistication of MRI hardware and software, abdominal and pelvic applications have proliferated. Until now, however, most clinical MR imaging of the female pelvis has focused on the uterus, the cervix, and to a lesser extent, on the ovaries. The deep pelvis, crowded as it is with small structures, has remained more of a challenge. Due in part to the poor CT tissue contrast in this area, most cross-sectional radiologists are not familiar with the detailed imaging features of the structures in and around the deep pelvis. Now, with further technical improvements in MRI, with increasing clinical interest in the pelvic floor, and with the radiologist's need to understand serendipitous discoveries made during imaging for other reasons, this is an area that deserves attention.

Key Issues: This exhibit will showcase the anatomy of the deep female pelvis and perineum, focusing on the most useful MRI pulse sequences and imaging planes. Pathologies of the urethra, vagina, vulva, clitoris, and anorectum will be illustrated, and will include a spectrum of inflammatory, neoplastic, congenital and iatrogenic etiologies.

Format: The format of the exhibit will blend didactic and case-based methods with an organizational structure based on pathological findings.

Teaching Points: 1. Participants will learn about the complex anatomy of the deep female pelvis and perineum. 2. Participants will learn about potential indications and appropriate MR techniques for imaging the deep pelvis. 3. The exhibit will prepare participants to detect and diagnose lesions unexpectedly encountered while interpreting routine musculoskeletal or gynecological MR examinations so they can avoid interpretive downfalls.

E225. Utility of MRI in Diagnosing Congenital Uterine Anomalies

Chaudry S. University of Washington, Seattle, WA

Address correspondence to S. Chaudry (sidhartha.chaudhry{at}gmail.com)

Background: Congenital uterine anomalies (congenital Mullerian duct anomalies) are present in 0.2 to 0.4% of women. However up to one in five women with recurrent pregnancy loss has a uterine anomaly. Accurate characterization of the anomaly helps identify patients who would benefit from surgical therapy, such as patients with septate uterus. It also helps in predicting prognosis.

Key Issues: Anatomic Issues: Most cases of Mullerian ductal anomalies can be explained by insufficient progressive caudal to cranial fusion. These may be associated ovarian and renal anomalies. Imaging Technique: Oblique coronal (horizontal long axis) and oblique axial (short axis) fast spin echo T2-weighted images are obtained using a phased-array pelvic multicoil. Typical parameters are TR/TE/ETL: 4000/102/16, 20–24 cm FOV, matrix 512 x 512, 4 signal averages, 4/1 mm slice thickness. Imaging findings: Horizontal long axis images help assess fundal dip and intercornual distance, which help in distinguishing arcuate uterus from bicornuate uterus. These images also are useful in characterizing the septum in a septate uterus. Short axis images help in identifying caudal extent of a uterine septum to distinguish between bicornuate-unicollis uterus from bicornuate-bicollis uterus. Antinatal DES exposed uterus has a characteristic T-shaped appearance on horizontal long axis images. Other features to look for are structure of ovaries as some of these cases may be accompanied with streak or rudimentary ovaries. Renal anomalies may be associated with uterine anomalies. Clinical significance: MR with T2 WI is the most accurate method of characterizing uterine anomalies, with diagnostic accuracy exceeding laparoscopy, ultrasound, and hysterosalpingogram.

Format: This exhibit will be presented in a didactic format highlighting clinical issues, technical factors, key imaging findings and pitfalls of different types of uterine anomalies presented in a systematic manner.

Teaching Points: From this exhibit, the viewer will be able to: 1. Identify different types of congenital uterine anomalies and their clinical features. 2. Know how to protocol a pelvic MR directed toward identifying uterine anomalies. 3. Know the diagnostic pitfalls to avoid when diagnosing uterine anomalies.

E226. Ectopic Pregnancy: A Pictorial Review

Kruger A. Y.; Ghoshhajra B.; Beasley H. Western Pennsylvania Hospital, Pittsburgh, PA

Address correspondence to A. Kruger (ifdg442{at}yahoo.com)

Background: The purpose of this exhibit is: 1. To review the ultrasound (US) appearances of normal first trimester pregnancies. 2. To review the pathophysiology and clinical presentations of ectopic pregnancies. 3. To review the US appearances of ectopic pregnancies.

Key Issues: Review of the pathophysiology, clinical presentations, and imaging findings on US of ectopic pregnancies in comparison to normal first trimester pregnancies.

Format: The format of this exhibit will be didactic and it will be organized by pathology.

Teaching Points: After completing this exhibit, the viewer will be able to recognize the ultrasound appearances of normal first trimester pregnancies and the clinical presentations, the pathophysiology, and the US findings associated with ectopic pregnancies.

E227. Use of MR Imaging in Surgical Triage and Treatment Planning of Female Pelvic Floor Disorders

Boyadzhyan L.¹; Raman S.¹; Rodriguez L.²; Raz S.² 1. UCLA Department of Radiology, Los Angeles, CA; 2. UCLA Department of Urology, Los Angeles, CA

Address correspondence to L. Boyadzhyan (lboyadzhyan{at}mednet.ucla.edu)

Background: Pelvic floor disorders (PFD) are an important social and medical problem affecting middle aged and older women worldwide. Up to 10% of women in the United States develop such severe PFD that they require surgery. Unfortunately, the pathophysiology of these disorders is poorly understood leading to failed surgical repairs in about a third of patients. Since clinical scoring systems do not directly assess surgical anatomy, at our institution and at others, static and dynamic MR imaging is used to supplement physical findings in selecting surgical candidates and in planning surgical repairs. In this exhibit, we will share our experience as a major referral center for PFD in order to demonstrate the role of MR imaging in surgical triage and treatment planning of our surgical patients.

Key Issues: This exhibit will demonstrate and address the following: 1. Review of relevant pelvic floor and organ anatomy as it relates to key anatomical changes associated with respective pelvic floor pathology seen in patients. 2. Role of MR imaging in the overall clinical assessment of patients with PFD. 3. MR imaging protocols utilized for PFD patients. 4. Surgical repairs utilized for a given defect in the context of preoperative MR imaging evaluation of patients. 5. An objective grading system utilized at our institution for preoperative assessment of pelvic floor prolapse and pelvic floor relaxation. 6. Spectrum of relevant findings in the preoperative patient assessment and their role in the surgical treatment algorithm.

Format: The format of this proposed exhibit will include didactic review of: 1. Key anatomy and pathological changes associated with PFD and corresponding surgical repairs. 2. Overall clinical algorithm and role of MR imaging. 3. MR imaging protocols 4. Examples demonstrating the spectrum of MR imaging findings seen in various defects 5. Key imaging findings in the preoperative assessment of patients 6. Quiz

Teaching Points: 1. Understand the concept of pelvic floor disorders with regards to surgical management. 2. Understand how static and dynamic MR imaging complements clinical information in surgical triage and treatment planning. 3. Recognize and objectively grade pelvic organ prolapse and pelvic floor relaxation. 4. Learn key MR imaging findings that imagers need to communicate to urogynecologists in the preoperative patient assessment.

E228. Unusual Cystic Pelvic Masses by MRI

Lebda P. L.; Beasley H. The Western Pennsylvania Hospital, Pittsburgh, PA

Address correspondence to P. Lebda (plebda{at}yahoo.com)

Background: Cystic pelvic masses are common in the pelvis and often not a diagnostic dilemma. However, the challenge lies with cystic pelvic masses of atypical appearance or unusual location. The multiplicity of elements in the pelvis makes a thorough differential diagnosis of cystic pelvic masses quite extensive. Therefore, it is imperative to be able to offer a limited yet appropriate differential diagnosis for unusual cystic pelvic masses.

Key Issues: This presentation focuses on the magnetic resonance appearance of unusual cystic masses in the pelvis. A spectrum of congenital, acquired, and neoplastic cystic pelvic masses is presented. The radiographic findings and pathology are discussed with each case.

Format: The exhibit will primarily entail a pictorial illustration of the radiological and pathological findings of unusual pelvic cystic masses. An appropriate differential diagnosis for each case will also be discussed.

Teaching Points: 1. Assist the radiologist in generating an appropriate differential diagnosis when encountering unusual cystic pelvic masses. 2. Identify radiologic characteristics of unusual cystic pelvic masses.

E229. The Multimodality Approach to Imaging the Postabortion and Postpartum Patient

Laifer-Narin S.; Reig, B. NY Presbyterian Hospital/Columbia University, New York, NY

Address correspondence to S. Laifer-Narin (sll2122{at}columbia.edu)

Background: Imaging is utilized to evaluate suspected complications during the postabortion or postpartum period. Common symptoms include abnormal vaginal bleeding, pelvic pain, and fever. Ultrasound is the first line imaging modality of choice. However, patients may undergo computed tomography, magnetic resonance imaging, and occasionally angiography for complete evaluation.

Key Issues: Postabortion complications include retained products of conception, arteriovenous malformations, and progression of gestational trophoblastic disease. Postpartum complications include bladder flap and subfascial hematomas, ovarian vein thrombophlebitis, uterine dehiscence and rupture, infection including endometritis and abscesses, and rare entities including pseudoaneurysm following cesarean section. Pertinent imaging findings as seen on ultrasound, CT, MRI, or angiography will be discussed.

Format: This will be presented in a didactic format and organized by pathology.

Teaching Points: At the end of the exhibit the viewer will be familiarized with postabortion and postpartum complications and their imaging findings.

E230. Multimodality Imaging of Tumor Vascular Response to Noninvasive Prostate Cancer Therapies

Bard R.²; Liebeskind M.³; Melnick J.¹ 1. Mount Sinai Medical School, New York, NY; 2. NY Medical College, Valhalla, NY; 3. NYU Medical School, New York, NY

Address correspondence to R. Bard (rbard{at}cancerscan.com)

Objective: The treated prostate gland is difficult to evaluate by standard transrectal US and noncontrast MRI. Non invasive therapies have been extensively studied in Europe and Japan that use decrease in tumor neovascularity as a surrogate treatment end point. Vascular tumor response to high intensity focused ultrasound (HIFU) and antioxidant therapies imaged by power Doppler sonography (PDS) and CE-MRI is presented.

Materials and Methods: Prospective study of 559 patients over 3 years. Gleason grades from 6 to 9. Ages from 37–94 years. All patients were scanned with 3D-PDS using a Voluson 730 (6–10 MHZ probe) and computer aided evaluation of dynamic MRI (1.5 T) without endorectal coil using a Siemens Symphony unit within a 1-week time frame. Six-month follow-ups were obtained. Thirty-one HIFU patients with 4 repeat treatments and 191 patients choosing antioxidant therapies were reviewed.

Results: Five of 31 HIFU patients demonstrated vascular recurrence of tumor by imaging and PSA rise at 6 months. Thirty-eight of 191 patients on antioxidant therapies showed initial PSA decrease at 3 months followed by recurrent neovascularity and rising PSA at 6 months. Agreement between 3TP CE MRI and 3D PDS was 94% on 452 exams of 212 patients studied.

Conclusion: Vascular imaging of anaplastic cancers is important since these tumors do not generate significant PSA levels. Successful detection of tumor recurrence post HIFU and postantioxidant treatment offer patients the option to choose other modalities in a timely manner. Vascular imaging may detect local recurrence in the prostate region opposed to PSA rise resulting from distant nodal and boney metastases.

E231. MR Imaging and MR Spectroscopy of Prostate Cancer: Review of Technique, Indications, and Emerging Relevance in Planning Laparoscopic Prostatectomy

Gulati M.; Raman S.; Thomas A.; Reiter R. E.; Lu D. S. University of California, Los Angeles (UCLA), Los Angeles, CA

Address correspondence to M. Gulati (mittulgulati{at}gmail.com)

Background: MRI and MR spectroscopy (MRS) are increasingly being used to image prostate cancer for diagnosis, staging, and following known malignancies. More recently, these techniques offer the potential to help plan surgery and advise individual patients of the likely sequelae of radical prostatectomy.

Key Issues: Clinical variables such as PSA level and digital rectal exam have traditionally been used to select patients and plan surgery for prostate cancer. Imaging findings from MRI/MRS differ from these clinical variables in that they are spatially localized, offering the potential to individually tailor cancer therapy. This presentation begins with an overview of technique and findings of MRI/MRS in prostate cancer, illustrated by correlating radiological imaging with histopathology from prostatectomy specimens. We then describe cases of locally advanced prostate cancer in which preoperative MRI/MRS showed cancer extending to involve the neurovascular bundles (NVBs) and seminal vesicles. In these cases, imaging was used by the surgeon to guide preoperative planning, such as the decision to resect a NVB at the time of laparoscopic prostatectomy. Patients were preoperatively advised that their NVB would need to be resected, and were aware that this decision had implications for their postoperative potency. MRI/MRS offers valuable information to a clinician wishing to preserve a patient's NVBs and potency while ensuring negative surgical margins and an effective cancer operation. This is especially critical for laparoscopic surgery, where the surgeon lacks tactile feedback and is reliant on preoperative imaging and intraoperative tumor appearance in deciding about resecting or sparing vital structures.

Format: Didactic presentation with a combination of text, tables, and radiological and histopathological imaging. This will be integrated with cases of patients whose preoperative plans for laparoscopic prostatectomies were refined by incorporating MRI/MRS results.

Teaching Points: 1. Review of the indications and technique for performing MRI/MRS of prostate cancer, as well as the relevant imaging findings. 2. Understanding how MRI/MRS allows clinicians to better plan for and patients to better anticipate clinically relevant decisions, such as the need to resect a NVB during prostatectomy. 3. Understanding the clinical importance of MRI/MRS of prostate cancer in the increasingly prevalent setting of laparoscopic prostatectomy, in which the surgeon has no tactile feedback to help judge tumor extent.

E232. In-vivo Magnetic Resonance Imaging of the Prostate at 7 Tesla

Sammet S.; Jia G.; Koch R. M.; Schmalbrock P.; Knopp M. V. The Ohio State University, Department of Radiology, Columbus, OH

Address correspondence to S. Sammet (sammet.5{at}osu.edu)

Objective: Magnetic Resonance Imaging (MRI) of prostate cancer has expanded significantly at 1.5 T and at 3.0 T. Clinical assessment of the extent of prostate cancer is often difficult because of the relatively small size and complex anatomy of the prostate and its inaccessible location deep within the pelvis. MRI at ultra-high field (7.0 T) scanners might offer an even higher resolution than 1.5-T and 3.0-T MR scanners. We investigated the potential of prostate MR imaging in vivo on a 7.0-T whole-body MR scanner in dogs.

Materials and Methods: The rumps of three male beagles were examined in a transmit/receive head coil of a 7.0-T whole-body MR-scanner (Philips Medical Systems). T2-weighted turbo spin echo sequences (TR = 5500 ms, TE = 88 ms, slice thickness = 2 mm, matrix size: 512 x 512) were acquired in axial (FOV = 140 mm) and coronal direction (FOV = 200 mm).

Results: 7.0-T MRI of the prostate in an ultra-high field whole-body MR scanner is possible. High-resolution MR images of the prostate of dogs were acquired at 7.0 T. A second order shim reduced susceptibility artifacts significantly. 7.0-T MR images with an in-plane-resolution of 0.27 mm x 0.27 mm prevailed anatomical structures of the prostatic gland like collagen and smooth muscle in the secretory tissue that can not be seen on low field strengths.

Conclusion: In vivo MRI of the prostate at 7.0-T is possible and shows additional anatomical structures compared to lower field-strengths. Ultra-high-field MRI could help to improve the noninvasive diagnostics of prostate cancer already in early stages. High-resolution MRI at ultra-high fields can reveal details to improve the accuracy of prostate cancer diagnosis and treatment control.

E233. Advancements in MRI Imaging of the Prostate Including MRS and Dynamic MRI Imaging: A Review of the Literature

Fadell M. F.; Barak R. University of Toledo, Toledo, OH

Address correspondence to M. Fadell (mfadell{at}meduohio.edu)

Background: Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are techniques that are FDA-approved, and have shown clinical utility in assessing prostate cancer. Combined, these modalities provide anatomic as well as metabolic information. In addition, recent studies have shown that dynamic contrast-enhanced MRI (DCE-MRI) provides further data that is beneficial in both detection and staging of prostate cancer. These techniques have proven to be more accurate than MRI alone in identifying the location as well as extent of prostate cancer.

Key Issues: Based on a review of the literature, the exhibit will address the anatomic and physiologic information provided by MRS and DCE-MRI in comparison to MRI alone in imaging prostate cancer. This will include, but is not limited to, the unique spectra seen with prostate cancer per MRS as well as the distinctive imaging characteristics seen with DCE-MRI secondary to the hypervascular nature of adenocarcinoma of the prostate.

Format: This didactic educational exhibit will address findings from a review of the literature pertaining to the diagnostic information gained from magnetic resonance spectroscopy (MRS) and dynamic contrast-enhanced MRI (DCE-MRI) pertaining to diagnosis and staging of prostate cancer in comparison to MRI alone.

Teaching Points: 1. The additional information gained by MRS in reference to MRI alone when imaging cancer of the prostate. 2. The additional information gained by DCE-MRI in reference to MRI alone when imaging cancer of the prostate. 3. What the benefits are of MRS and DCE-MRI in diagnosing and staging prostate cancer. 4. What the benefits are in combining MRI, MRS, and DCE-MRI in diagnosing and staging prostate cancer.

E234. MR Imaging (MRI) and MR Spectroscopy (MRS) as Preoperative Aids: Report of Experience and Utility in Planning Robotically Assisted Laparoscopic Radical Prostatectomy (RALRP)

Gulati M.; Raman S. S.; Reiter R. E.; Thomas G. V.; Thomas A.; Lu D. S. University of California, Los Angeles (UCLA), Los Angeles, CA

Address correspondence to M. Gulati (mittulgulati{at}gmail.com)

Objective: 1) To evaluate our experience with MRI/MRS for prostate cancer detection and staging, using both biopsy results and pathology following prostatectomy as reference standards. 2) To describe the utility of MRI/MRS in planning surgical approach for robotically assisted laparoscopic radical prostatectomy (RALRP).

Materials and Methods: With IRB approval, we retrospectively evaluated the records of patients who had undergone endorectal 1.5-T MRI/MRS over a two-year period. All patients underwent a prostate biopsy prior to MRI/MRS. We coringly prevalent surgical approach which, unlike traditional open radical prostatectomy, offers no tactile feedback to the surgeon. We further analyzed imaging and pathology results in this subgroup, with a special interest in identifying cases where MRI/MRS helped to preoperatively plan the prostatectomy.

Results: 39 patients underwent MRI/MRS of the prostate following a prostate biopsy. Using biopsy results as the reference standard, sensitivity and specificity of MRI/MRS for cancer detection was 85% and 50%, respectively. Positive and negative predictive values were 79% and 60%, and accuracy in cancer detection was 74%. A subgroup of 16 of these 39 patients with prostate cancer went on to RALRP. In this subgroup, MRI/MRS correctly staged 12 of 16 patients, or 75%. MRI/MRS understaged 4 of the patients, or 25%, including 2 with small foci (<1 cm) of cancer on final histopathology (stage T2), and one each with T3 and T4 cancer. Most significantly, three cases were identified where MRI/MRS demonstrated extension of cancer outside the capsule and involvement of the neurovascular bundle (NVB) unilaterally, allowing the surgeon to plan wide resection of the NVB on the involved side to achieve negative surgical margins. These cancers were not palpable on digital rectal exam (DRE), and would have been undetected relying on traditional clinical staging criteria (PSA level plus DRE) in the absence of MRI/MRS.

Conclusion: Cancer detection with MRI/MRS was similar to that in previous studies by other groups. To our knowledge, this is the first report utilizing MRI/MRS of the prostate to preoperatively plan NVB resection in RALRP. MRI/MRS offer potential as planning aids for this increasingly prevalent surgical technique, and are especially important given the lack of tactile feedback in RALRP compared with open surgery.

E235. Ultrasound of the Acute Scrotum

Stein M. Albert Einstein College of Medicine/ Montefiore Medical Center, Bronx, NY

Address correspondence to M. Stein (mstein17{at}aol.com)

Background: There are numerous causes of acute scrotal pain. The most common causes include epididymo-orchitis, testicular torsion, torsion of the testicular appendages, and trauma. Less frequent etiologies include an incarcerated inguinal hernia, idiopathic scrotal edema, Henoch Schonlein purpura, and hemorrhage or infarction in a neoplasm. The purpose of imaging is to determine whether testicular torsion is present, which is a surgical emergency, and to distinguish it from nonoperative conditions such as torsion of a testicular appendage or epidiymo-orchitis.

Key Issues: Normal scrotal anatomy will be reviewed as well as anatomic abnormalities such as the bell clapper deformity. Clinical features distinguishing intravaginal and extravaginal torsion will be discussed. Imaging features of acute, subacute and chronic testicular torsion will be demonstrated as well as pitfalls in diagnosing torsion and related conditions as torsion/detorsion and appendage torsion. The pathophysiology of epididymo-orchitis, its grey-scale and Doppler sonographic findings and the findings with complications such as pyocele, testicular abscess, scrotal abscess, and segmental or complete infarction will be thoroughly reviewed. The myriad appearances of scrotal trauma will be highlighted including hematocele, hematoma/contusion, and testicular rupture.

Format: This will be a didactic presentation. Differential diagnoses will be highlighted. This will be followed by written text of the clinical and radiologic manifestations of each entity followed by illustrative grey scale and Doppler sonographic images.

Teaching Points: 1. To be able to list the various causes of acute scrotal pain. 2. To distinguish testicular torsion from other causes of acute pain such as torsion of testicular appendages and epididymo-orchitis and to avoid pitfalls in their sonographic diagnosis 3. To be able to diagnose complications of infection such as pyocele, scrotal abscess, testicular infarction, and Fournier gangrene. 4. To recognize various appearances of scrotal trauma on sonography 5. To be able to combine the clinical history, results of palpation and the structural and perfusion changes of the scrotal contents to establish the correct diagnosis in complex cases.

E236. Imaging of the Epididymis

Lee J.; Bhatt S.; Dogra V. University of Rochester, Rochester, NY

Address correspondence to J. Lee (Jerry_Lee{at}urmc.rochester.edu)

Background: Ultrasonography performed with high transducer sonography is the modality of choice for evaluating acute scrotal pain. Many disease processes, including testicular torsion and epididymo-orchitis, produce the common symptom of scrotal pain at presentation and differentiation of these conditions is important for determining the appropriate treatment.

Key Issues: Epididymo-orchitis is the most common cause of acute scrotal pain in adolescent boys and adults. High resolution ultrasonography plays an important role in helping differentiate acute epididymo-orchitis from testicular torsion, which is a surgical emergency. Both manifest with acute pain and swelling. Clinical differentiation of these conditions is difficult with a false-positive rate of nearly 50% for the diagnosis of testicular torsion based on clinical findings alone. Epididymitis is commonly secondary to sexually transmitted organisms. Rare causes such as sarcoidosis, brucellosis, tuberculosis, cryptococcus, and mumps may also cause epididymitis. Drugs such as amiodarone hydrochloride may also cause epididymitis (chemical epididymitis).

Format: Didactic presentation demonstrating normal anatomy using high resolution sonography in gray-scale, color flow, and power Doppler. Images demonstrating acute epididymo-orchitis, granulomatous diseases of epididymis (sarcoid and tuberculosis), and benign and malignant tumors of epididymis will be presented. Epididymitis secondary to trauma will also be presented. The exhibit will conclude with a short quiz to summarize key points pertaining to imaging of epididymis.

Teaching Points: 1. Learn the normal high resolution sonographic anatomy of the epididymis. 2. Recognize the sonographic features of epididymo-orchitis that help in differentiating it from testicular torsion. 3. Recognize the sonographic findings of benign and malignant tumors of the epididymis.

E237. Non-neoplastic Intratesticular Masses–Role of Gray Scale and Color Doppler Sonography

Bhatt S.²; Jafri S. H.³; Wasserman N. F.¹; Dogra V. S.² 1. University of Minnesota, Minneapolis, MN; 2. University of Rochester Medical Center, Rochester, NY; 3. William Beaumont Hospital, Royal Oak, MI

Address correspondence to S. Bhatt (shweta_bhatt{at}urmc.rochester.edu)

Background: Five percent of all intratesticular lesions are benign. Ultrasound plays an important role and adds essential information in diagnosing benign intratesticular lesions. Characterization of benign intratesticular lesions with sonography, in combination with clinical assessment can lead to nonsurgical management or testicular sparing surgery.

Key Issues: The purpose of this exhibit is to expose radiologists to a series of challenging cases in order to help improve the radiologist's diagnostic accuracy of these benign intratesticular masses. Key differential diagnostic points will be highlighted in the discussion of each case. The list of cases includes: 1) Focal infarcts. 2) Intratesticular hematomas. 3) Epidermoid cysts. 4) Intratesticular cysts. 5) "Intratesticular tumor" of the adrenogenital syndrome. 6) Intratesticular varicocele. 7) Intratesticular AVM. 8) Sperm granuloma. 9) Testicular lipomatosis in Cowden's disease. 10) Postradiation change and postbiopsy scar.

Format: Exhibit presentation of various benign intratesticular lesions in a quiz format.

Teaching Points: 1. To understand the sonographic anatomy of the testis. 2. To describe the sonographic features of various nonneoplastic, benign intratesticular masses such as intratesticular hematomas, infarcts, cysts, intratesticular varicocele, etc. 3. To understand the role of color-flow Doppler in identifying the non neoplastic intratesticular masses.

E238. Male Infertility: Transrectal Ultrasound Assessment

Abdel Razek A.; Elhanbaly S. Mansoura Faculty of Medicine, Mansoura, Egypt

Address correspondence to A. Abdel Razek (arazek{at}mans.eun.eg)

Background: Low volume azoospermia is a common cause of male infertility. Transrectal ultrasound examination (TRUS) is commonly used to differentiate surgically correctable distal obstructive lesions from those with noncorrectable congenital anomalies. Also, it identifies the cause and level of obstruction within the ejaculatory ducts.

Key Issues: Male infertility with low volume azoospermia may be due to congenital anomalous or acquired obstruction of the ejaculatory duct. Congenital abnormalities included aplasia or hypoplasia of the vas deferens, ampulla of vas and seminal vesicles. The obstructed lesions included fibrosis, calcification and calculi of the ejaculatory duct and associated cysts (n = 28). The cysts were located in the periurethral region (midline), along the ejaculatory duct or in the seminal vesicle. We concluded that TRUS is the ideal method for evaluating infertile men with low-volume azoospermia.

Format: The information will be in didactic format. First, describing transrectal ultrasound appearance of normal ejaculatory ducts and seminal vesicles, then ultrasound examination technique of ejaculatory ducts. Transrectal ultrasound findings of congenital and acquired causes of male infertility with low volume azoospermia will be reviewed in didactic format.

Teaching Points: The reviewer will be able to understand normal ultrasound of the ejaculatory ducts; be able to perform transrectal ultrasound examination of the ejaculatory ducts and be familiar with ultrasound features of congenital and acquired lesions of infertile male with azoospermia.

E239. Fetal MR: Feasible, Safe and Helpful

Oliveira P.; Goldman S.; Amaral R.; Santos G.; Demarchi G.; Szejnfeld D.; Rezende C.; Abdala N.; Szejnfeld J. UNIFESP, Sao Paulo, Brazil

Address correspondence to P. Oliveira (patiso{at}uol.com.br)

Background: Fetal MR is a feasible, safe, comprehensive and very useful examination which serves perfectly as a complement for ultrasound studies. It is a decision-maker study, determining prognosis of the pregnancy and is also often used as a valuable planning tool for uterine and postpartum interventions.

Key Issues: We begin with a short description of fetal MR exam techniques and then we depict how normal fetal structures appear on MR. After that we present pathologic findings of: central nervous system malformations: agenesis of the corpus callosum, holoprosencephaly, cephalocele, cortical development malformation and cerebellar dysgenesis. Urogenital anomalies: obstructive uropathy and primary renal dysplasia. Thoracic: cardiac, pulmonary and diaphragmatic diseases. Bone dysplasias.

Format: Didactic presentation: 1. To review the basic techniques of fetal MR. 2. To correlate the most important ultrasound findings to fetal MR findings. 3. To demonstrate the value of fetal MR as a useful tool in complementing ultrasound studies.

Teaching Points: The viewer will become familiar with the pathologic findings of common problems encountered by the fetal/ObGyn radiologist such as central nervous system malformations, urogenital and cardiothoracic diseases as well as musculoskeletal findings.

E240. Pitfalls and Anatomic Variations in Fetal Ultrasound

Burns J.; Stein M. Montefi ore Medical Center, Bronx, NY

Address correspondence to J. Burns (judahburns{at}hotmail.com)

Background: It is crucial to rapidly and confidently recognize the timing of development, its variations and numerous pitfalls that are encountered during scanning and interpretation of normal obstetric sonograms. Misdiagnosis can result in unnecessary follow-up examinations, increased costs and parental worry. Excellence in obstetric sonography can only be achieved through recognition of the specific imaging features of basic pitfalls by ultrasound technologists and radiologists.

Key Issues: Errors in obstetric ultrasound evaluation can be grouped into errors of measurement, errors of interpretation and misinterpretation of normal findings and developmental variants. Examples include methodological measurement errors of the lateral ventricles, biparietal diameter, nasal bone, abdominal circumference, and nuchal thickness. Errors of interpretation include pseudolesions such as pseudohydrocephalus, pseudochoroid plexus cysts, pseudopericardial effusion, pseudoompalocele, and pseudoascites. Lack of recognition of the proper scanning plane can result in a false diagnosis of mandibular hypoplasia, enlarged cisterna magna, thickened nuchal fold and nuchal translucency, ventricular septal defect, and spinal dysraphism. Additionally, developmental variants and normal findings such as the fetal rhombencephalon, normal bowel herniation, and the unfused amnion in the first trimester must be properly evaluated and understood in relation to the stage of fetal development.

Format: This presentation uses a didactic format, with case examples and descriptive slides. Imaging pitfalls are highlighted by category and a framework for understanding the mechanism of misinterpretation of common variants is illustrated. Where possible, an anatomic basis will be provided to explain these findings. Tips for avoiding common misdiagnoses will be presented.

Teaching Points: 1. Anatomic and developmental variation is commonly noted in obstetric ultrasound. 2. Pitfalls may occur in measurement, interpretation and scanning which must be recognized by the technologist and radiologist. 3. Understanding the range of normal findings is as important as understanding pathology.

E241. Bladder Tumor Detection–MR Virtual Cystoscopy

Urbanik A.; Wojciechowski W.; Dobrowolski Z.; Chrzan R.; Popiela T.; Drewniak T.; Lipczyiski W. Collegium Medicum, Jagiellonian University–Kraków, Poland

Address correspondence to A. Urbanik (aurbanik{at}mp.pl)

Objective: The aim of the study is to present our experience on MR virtual cystoscopy.

Materials and Methods: 26 patients were subjected to ureterocystoscopy. All these patients were examined using Signa Horizon 1.5-T MR System (GEMS). The obtained images were transferred to the workstation for further processing by the software (3D and Navigator, GEMS). T1- and T2-weighted transverse cross-sections, 3D reconstructions, as well as static and dynamic virtual cystoscopy images were obtained. The results of the MR diagnostic procedures including virtual cystoscopy images were compared to the traditional cystoscopy findings.

Results: The analysis of the MR scans of urinary bladder confirmed the presence of tumors in all cases. Their localization, number and extent were evaluated. MR findings were correlated with those of the traditional cystoscopy.

Conclusion: Due to their high-resolution MR images of the urinary bladder allow very precise assessment of urinary bladder pathologies. Virtual cystoscopy provides an image of the urinary bladder without using endoscopy, ionizing radiation or contrast media. The method of MR virtual endoscopy is completely noninvasive and may be used for visualizing urinary bladder cavity in cases where the traditional cystoscopy is contraindicated. In addition, MR is the most accurate current method of assessing urinary bladder wall infiltration.

E242. Multimodality Imaging of Traumatic, Inflammatory, and Neoplastic Conditions of the Urethra

Hong S. C.³; Jafri Z.³; Amendola M. A.¹; Francis I. R.²; Amin M.³; Roy A.³; Gibson D.³ 1. University of Miami Medical Center, Miami, FL; 2. University of Michigan, Ann Arbor, MI; 3. William Beaumont Hospital, Royal Oak, MI

Address correspondence to S. Hong (shong{at}beaumont.edu)

Background: Despite advancements in cross-sectional imaging, retrograde urethrography and voiding cystourethrography remain the primary methods for imaging the urethra. However, cross-sectional modalities such as ultrasonography, computed tomography, and magnetic resonance imaging serve as valuable tools for diagnosis and for directing patient therapy. This exhibit will highlight these topics to familiarize the reader with the roles of these different diagnostic modalities in imaging urethral pathology.

Key Issues: The normal gross anatomy of the male and female urethra and their appearances on radiographic studies will be introduced. Then using multiple modalities, urethral trauma, inflammatory processes involving the urethra, and urethral neoplasms will be displayed and discussed. Radiologic and pathologic correlations will be made where applicable.

Format: Materials will be presented in a didactic format followed by a review to quiz the reader on the topics covered.

Teaching Points: 1. Understanding of normal urethral anatomy. 2. Radiographic presentation of urethral pathology, covering traumatic, inflammatory, and neoplastic processes. 3. Correlation of radiology and pathology in urethral disease. 4. Role of the various modalities in the evaluation of the urethra, including their advantages and/or disadvantages and limitations.

E243. Imaging of Inflammatory Conditions of the Urinary Tract; Impact of Recent Advances in Cross-sectional Imaging

Elsayes K. M.²; Platt J. F.²; Menias C. O.¹; Bude R. O.²; Hussain H. K.²; El-Diasty T.^3; Cohan R. H.² 1. Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO.; 2. University of Michigan Health Center, Ann Arbor, MI; 3. Mansoura University, Urology and Nephrology Center, Mansoura, Egypt

Address correspondence to K. Elsayes (kelsayes{at}med.umich.edu)

Background: Radiologic investigation continues to be one of the most important sources of clinical information in the evaluation of urinary tract inflammatory/infectious conditions. This exhibit illustrates a wide range of inflammatory/infectious conditions that involve the urinary tract. Cross-sectional imaging features will be discussed using a multimodality approach. Special emphasis will be placed on the role of recent advances of these modalities. Differential diagnoses and mimics will be discussed.

Key Issues: –Introduction. –Clinical features of inflammatory/infectious diseases of the urinary tract. –Imaging features of these diseases using US, MDCT, and MRI, –Utility of cross-sectional modalities and their recent advances in diagnosis of these diseases. –Differential diagnoses with a focus on imaging features that may help distinguish these conditions from other entities of the urinary tract. –Radiologic/clinical-pathologic correlation inflammatory/infectious conditions of the urinary tract.

Format: Organizational structure (by pathology, clinical features, techniques, imaging findings, differential diagnosis and radiologic/clinical-pathologic correlation.

Teaching Points: 1. To review the pathological spectrum of inflammatory conditions of the urinary tract. 2. To discuss the cross-sectional imaging spectrum of inflammatory conditions of the urinary tract and to correlate imaging findings with pathological findings. 3. To discuss the role of MDCT, MRI, US with their recent advances in the diagnosis of these diseases.

E244. Multidetector Row CT of the Urinary Tract: Newer Techniques and Strategies to Reduce Radiation Dose

Udayasankar U. K.¹; Namasivayam S.²; Baumgarten D.¹; Kalra M.²; Small W. C.¹ 1. Emory University School of Medicine, Atlanta, GA; 2. Massachusetts General Hospital, Boston, MA

Address correspondence to U. Udayasankar (uudayas{at}emory.org)

Background: Multidetector row CT (MDCT) studies are often used in the detection and follow up of urinary tract pathologies. Various techniques have been described in the literature for the evaluation of urinary tract calculi, living related renal donors, renal arterial pathologies, collecting system and renal masses. Newer technical advancements in this field are aimed at reducing the radiation dose of MDCT studies, while maintaining adequate visualization of the urinary tract.

Key Issues: The majority of the MDCT protocols for the evaluation of urinary tract pathology primarily aim to capture the gross anatomy, vascular components and functional aspects. Therefore, appropriate scan parameters, contrast dose and timing of scans are imperative to arrive at an accurate clinical diagnosis. One of the limitations of using MDCT is the associated radiation burden.

Format: This exhibit will be in the form of a didactic lecture which will give a detailed description of newer MDCT protocols in urinary tract studies and describe the technical innovations adopted to reduce radiation and contrast material dose in these studies. Data will be presented in the form of charts, tables and diagrams. A highly structured approach will be presented for proper evaluation of 1. Urinary tract calculi 2. Renal collecting system, ureters and urinary bladder 3. Living related renal donors, and 4. Renal mass. Strategies discussed will include 1. Changes in the number of phases of acquisition 2. Automatic exposure control techniques 3. Utilization of a lower tube potential

Teaching Points: MDCT is extensively used in the assessment of urinary tract diseases. However, radiation dose associated with MDCT examinations of the urinary tract raises concern. The major teaching point of this exhibit is to highlight the improvements in technology and protocols and to illustrate strategies being adopted to reduce the radiation burden and the amount of radiation received from MDCT studies. Use of automatic exposure control, reduced tube current potential and modified contrast injection techniques will be highlighted.

E245. MRI vs Ultrasound Examinations in Congenital Malformations of the Urinary Tract

Urbanik A.¹; Herman-Sucharska I.¹; Szafirska M.¹; Rytlewski K.²; Mamak-Balaga A.²; Grzyb A.²; Basta A.² 1. Collegium Medicum Department of Radiology, Jagiellonian University – Kraków, Poland; 2. Department of Gynaecology, Obstetrics and Oncology, Jagiellonian University Medical College, Kraków, Poland

Address correspondence to A. Urbanik (aurbanik{at}mp.pl)

Objective: Oligo/ahydramnios is one of the most dangerous diagnostic signs that occur in pregnancy. The appropriate diagnosis of its presence and cause is the crucial point of the appropriate medical management. Thus, prenatal evaluation should be based on infallible grounds. The aim of the study was comparison of ultrasonographic and subsequent MR evaluations in pregnancy complicated with suspicion of fetal urinary tract malformations.

Materials and Methods: 32 pregnant women with suspicion of fetal urinary tract malformations, between 18 and 32 weeks of pregnancy, underwent ultrasound examinations [Voluson-Kretz730PRO], followed by MR [1.5-T GE Excite system, flex coil, SSFSET2 sequence].

Results: In 32 pregnant women with suspicion of fetal urinary tract malformations 34 ultrasound and MR examinations were performed. Because of difficulties with the proper diagnosis, these procedures were repeated in two cases after amnioinfusion. The mean maternal and gestational ages were 22.6 ± 3.6 years, and 22 ± 4.4 weeks, respectively. In anamnesis – 8 losses of previous pregnancies were observed. In 14 cases both, US and MR, showed: oligohydramnios, renal agenesis and the absence of the urinary bladder (6 cases) or oligohydramnios, polycystic kidneys and visible urinary bladder (8 cases). In 14 cases both US and MR showed: normal volume of hydramniotic fluid, present urinary bladder and polycystic kidneys. In the other cases, when polycystic kidneys coexisted with invisible in US urinary bladder, MR showed it in 1 case. Moreover, there was 1 case of oligohydramnios, renal agenesis and absent urinary bladder (US), whereas MR showed renal hypoplasia and cloaca. In 2 cases of invisible kidneys in US (described as renal agenesis) MR showed hypoplastic kidney (1) and policystic dystopic kidney (1).

Conclusion: It seems that suspected fetal malformations should be diagnosed using different diagnostic procedures in order to avoid misdiagnosis. MR seems to be a better method to recognize fetal genitourinary malformations.

E246. Living Donor Kidneys: Utility of 16-Slice Multidetector Row CT for Preoperative Evaluation

Radwan S. M.²; Ali M.²; Abou Elabbas H. A.²; Elsetouhy A.¹; Sayed Ahmed T. I.³ 1. Faculty of Medicine, Cairo University, Cairo, Egypt; 2. Theodor Bilharz Research Institute, Giza, Egypt; 3. Urology and Nephrology Center, Mansoura University, Mansoura, Egypt

Address correspondence to S. Radwan (shradwan{at}hotmail.com)

Objective: To assess in living renal donors the accuracy of 16-slice multidetector row CT (MDCT) in the evaluation of renal vasculature and the upper urinary tract by using surgery as the reference standard.

Materials and Methods: This study was approved by our institutional review board for human investigation. 63 consecutive potential kidney donors (38 men and 25 women; mean age, 40.7 years) underwent 16-channel MDCT. Unenhanced CT of the abdomen was performed. Next, 100 mL of nonionic contrast material was injected at a rate of 4–5mL/sec. Arterial, nephrographic and excretory phase volumetric data sets were acquired at 20–25 seconds, 70–75 seconds, and 10 min. after start of injection, respectively. Volumetric reconstructions were performed at a CT workstation for the 1mm sections of the arterial and nephrographic phases. These included coronal and oblique coronal overlapping thin MIP as well as 3D MIP reconstructions parallel to the renal hilar vessels. CT urographic images were reconstructed from the excretory phase CT data in the coronal or oblique coronal plane by using MIP. Each scan was evaluated independently for renal vascular and ureteral anatomic variants. Findings at CT were compared with those at surgery. Sensitivity, specificity and accuracy of MDCT were calculated on the basis of presence or absence of variant anatomy at surgery.

Results: CT depicted 76 of 77 renal arteries confirmed at surgery; one accessory artery was misinterpreted at CT as early branching artery. CT depicted 66 of 67 renal veins confirmed at surgery. Overall accuracy of CT was 98.4%, 98.4%, and 100% for identification of variant anatomy of renal arteries, veins and ureters, respectively.

Conclusion: 16-channel MDCT used as the sole minimally invasive imaging technique in the comprehensive evaluation of living renal donor candidates provides high accuracy for detecting renovascular and ureteric anomalies.

E247. Utility of Voxel-by-Voxel Subtraction Images in MRI of the Kidneys

Myers L.; Nikolaidis P.; Hammond N.; Yaghmai V.; Summers A.; Gabriel H.; Miller F. Northwestern University, Feinberg School of Medicine, Chicago, IL

Address correspondence to L. Myers (Lee.Myers{at}students.rosalindfranklin.edu)

Background: Determining the presence of enhancement in renal lesions is vital in reaching the correct diagnosis on contrast-enhanced CT and MR. The presence of enhancement in a renal lesion often differentiates a tumor from a benign lesion. Measurement of attenuation (Hounsfield units) on CT is a proven, reliable method to determine the presence of abnormal enhancement. To date, the validity of similar ROI measurements on pre- and postcontrast gadolinium enhanced MRI of the kidneys has not been fully established. Simple visual comparison of pre- and post-gadolinium sequences is not an acceptable, objective means in determining the presence of enhancement particularly in lesions that have high signal on precontrast sequences. An alternative technique that has been described in the radiology literature is voxel-by-voxel subtraction of precontrast images from contrast-enhanced images. This technique has been successfully utilized to determine the presence of enhancement on breast and body MR imaging and has been routinely used for postprocessing in contrast-enhanced MR angiography.

Key Issues: The imaging technique described is voxel-by-voxel subtraction of precontrast images from contrast-enhanced MR images. Specific entities will be shown where subtraction images were helpful in establishing the correct diagnosis and guiding appropriate management.

Format: This didactic exhibit will showcase a wide variety of renal pathology including several examples of Bosniak I-IV renal cystic lesions, solid neoplasms, hemorrhagic renal and perirenal lesions as well as pseudolesions. In selected cases, correlative CT and ultrasound images or subsequent follow-up studies will be shown. Several pitfalls and technical artifacts associated with subtraction images will be illustrated.

Teaching Points: The use of subtraction images on contrast-enhanced MR of the kidneys is an essential, viable diagnostic tool for the correct diagnosis of a wide variety of renal lesions. Information gathered from this technique is vital in ensuring proper diagnosis and medical management of a wide spectrum of pathology involving the kidneys. The radiologist should be aware of several common artifacts and pitfalls of this technique.

E248. Multimodality Imaging of Retroperitoneal Fibrosis

Young P. M.; Peterson J. J. Mayo Clinic, Jacksonville, FL

Address correspondence to P. Young (young.phillip{at}mayo.edu)

Background: Retroperitoneal fibrosis represents the end result of a spectrum of primary and secondary inflammatory processes. The clinical diagnosis may be quite difficult, owing to insidious symptoms with a slow onset. Imaging findings have been described using multiple modalities, but little consensus exists on the optimal imaging strategy to guide disease management and intervention.

Key Issues: Retroperitoneal fibrosis may be primary and idiopathic (Ormond's disease) or secondary to a number of disease processes. Of primary importance in evaluating patients with proven or suspected retroperitoneal fibrosis is determination of its effect on the function of the kidneys and ureters, as well as the abdominal aorta. An accurate description of the involved anatomic territory and associated abnormalities may provide clues to the underlying etiology. Distinguishing active inflammatory processes from anatomic distortion resulting from "burned" out fibrosis will help the clinician in planning the course of pharmacotherapy. The role of contrast-enhanced CT and MRI will discussed, as will the evolving role of F-18 FDG PET.

Format: The format will rely on didactic presentation of information combined with a multimodality pictorial essay of patients with this interesting disease. Modalities shown will include conventional excretory urography, CT excretory urography, MRI, and F-18 FDG PET.

Teaching Points: 1. Retroperitoneal fibrosis can occur as a primary, idiopathic disease, as well as in association with other diseases such as inflammatory atherosclerotic disease, collagen vascular disorders, radiation, malignancy, infection, and amyloidosis. 2. Imaging should be guided to help elicit active from "burned out" disease, as well as to ascertain the underlying etiology of the disorder. 3. Contrast enhanced CT and MRI, as well as F-18 FDG PET, may play a useful role in the evaluation of disease activity. Excretory urography and CT excretory urography may define distortion and obstruction of the ureters. 4. Traditional modalities, such as excretory urography, still play an important role in disease monitoring, as do advanced modalities such as MDCT excretory urography.

E249. MR Imaging of the Retroperitoneum: Anatomy and Disease Spectrum

Alvarez D.²; Lall C.¹; Cohen A. J.² 1. Indiana University Medical Center, Indianapolis, IN; 2. University of California, Irvine, Irvine, CA

Address correspondence to D. Alvarez (alvarezd{at}uci.edu)

Background: The retroperitoneum is a complex compartmentalized space located external to and posterior to the parietal peritoneum. It contains vital organ systems including the genitourinary and pancreaticobiliary systems. This is often the site of varying disease processes and pathology. MRI has superior contrast resolution as compared with CT and is useful in differentiating various disease processes and tissue characterization. This exhibit will evaluate various retroperitoneal disease processes and examine conduits of disease spread between the peritoneuma and retroperitoneal spaces.

Key Issues: 1. Anatomy of the retroperitoneal spaces on MR. 2. Recognize potential pathways of disease spread between the peritoneal and retroperitoneal compartments. 3. MR imaging features of diseases affecting the nonparenchymal portions of the retroperitoneum.

Format: 1. Interactive, didactic format. 2. Review of pertinent retroperitoneal anatomy. 3. Explore pathways of disease spread via conduits linking the peritoneal spaces and retroperitoneum.

Teaching Points: 1. Review of retroperitoneal anatomy. 2. Study conduits linking the peritoneal spaces and retroperitoneum. 3. Spectrum of nonparenchymal retroperitoneal abnormalities, evaluation and differential diagnoses.

E250. Imaging of Renal Transplantation: A Primer for Residents

Rausch D.; Simpson W. Mount Sinai Medical Center, New York, NY

Address correspondence to D. Rausch (danarausch{at}hotmail.com)

Background: Cadaveric and living related donor renal transplantation is a common surgical treatment for patients with end stage renal disease. Ultrasound and CT or MR angiography are routinely used in the preoperative evaluation and selection of potential living related renal donors. Postoperatively, ultrasonography is routinely employed to evaluate for potential complications. It is essential that residents and radiologists be familiar with the pre- and postoperative imaging assessment of renal transplants.

Key Issues: The multimodality preoperative evaluation of potential renal donors used to determine their suitability for transplantation will be illustrated. A brief discussion of the surgical procedure, as well as the normal sonographic appearance of the transplanted organ will be presented. The role of imaging of potential transplantation complications such as vascular compromise, parenchymal pathology, collecting system obstruction, and peritransplant collections will be discussed, as will possible image-guided intervention.

Format: This exhibit will be presented in a didactic format, organized by pathology.

Teaching Points: 1. To understand the multimodality imaging approach to potential renal donors in surgical planning. 2. To familiarize the resident/radiologist with the basic surgical procedure and normal sonographic appearance of the renal transplant. 3. To demonstrate the role of imaging in the diagnosis and treatment of potential complications of renal transplantation. 4. To improve the diagnostic ability of the participant.

E251. Evaluation of Clinically Significant Renal Artery Stenosis with Gadolinium-Enhanced MR Angiography: Comparison with Digital Subtraction Angiography

Law Y.; Tay K.; Gan Y.; Cheah F.; Tan B. Singapore General Hospital, Singapore

Address correspondence to Y. Law (yanmee{at}hotmail.com)

Objective: To evaluate the accuracy of gadolinium-enhanced magnetic resonance angiography (MRA) in assessing renal artery stenosis compared to catheter digital subtraction angiography (DSA).

Materials and Methods: This is a retrospective study involving a review of records of patients who underwent MRA as well as DSA for assessment of renal artery stenosis (RAS) from January 2003 to December 2005. There were 27 patients (14 men, 13 women) with a mean age of 62 years, 2 patients deceased (range 44 to 77 years). There were 7 patients with renal transplants and the native renal arteries were not evaluated in these patients. A consultant interventional radiologist reviewed the DSA images while a consultant body radiologist familiar with visceral MRA reviewed the MRA images. The former was blinded to the MRA images while the latter was blinded to the DSA images. DSA was used as the standard of reference. The renal arteries were graded as being normal, having mild (<50%), moderate (>50% but <75%) or severe (>75%) stenosis. Clinically significant stenosis was taken as >50% stenosis.

Results: A total of 39 renal arteries from these 27 patients were evaluated. One of the arteries was previously stented and could not be assessed with MRA due to severe artifacts (severe instent stenosis was noted on DSA). Of the remaining 38 renal arteries, 2 were graded as normal, 7 had mild stenosis, 8 had moderate stenosis and 21 had severe stenosis. MRA and DSA were concordant in 74%, MRA overestimated the degree of stenosis in 16% and underestimated in 10%. In the evaluation of clinically significant RAS (>50%) with MRA, the sensitivity was 97%, specificity was 67%, positive predictive value was 90% and negative predictive value was 86%.

Conclusion: Our experience suggested that gadolinium-enhanced MRA is a sensitive noninvasive modality in the assessment of clinically significant renal artery stenosis. MRA is however unable to assess vessels which had prior stenting due to stent artifacts.

E252. Accessory Renal Arteries Stenosis: Evaluation of Efficacy by Using Different Postprocessing Procedures in Multidetector-Row CT

Saba L.¹; Caddeo G.¹; Sanfilippo R.²; Montisci R.²; Mallarini G.¹ 1. Policlinico Universitario di Monserrato, Radiology, Cagliari, Italy; 2. Policlinico Universitario di Monserrato, Vascular Surgery, Cagliari, Italy

Address correspondence to L. Saba (lucasaba{at}tiscali.it)

Objective: Hypertension may be produced by the stenosis of renal arteries and in literature it is debated the role of the accessory renal arteries in this pathology. Our objective was to compare different postprocessing procedures, by using CTA in order to evaluate their efficacy in detecting accessory renal arteries and their potential stenosis.

Materials and Methods: We retrospectively studied 138 patients (87 men; 51 women, mean age: 64 years) who underwent an MDCTA to study abdomen vasculature. Patients were studied by using a multidetector-row CT and images were obtained after intravenous bolus administration of 110–140 mL of nonionic contrast material using a 3–6 mL/sec flow rate. For each patient we generated maximum intensity projection (MIP), multiplanar reconstruction (MPR) and volume rendered images (VR). Two radiologists reviewed MDCTA images independently and we calculated interobserver agreement.

Results: The overall number of accessory renal arteries detected were 46 in 35 patients. Stenosis in the accessory renal artery was detected in 12 cases by using MIP, in 9 cases by using VR and in only 6 cases by using MPR reconstruction. Interobserver agreement was good by using MIP and VR but was poor with the use of MPR.

Conclusion: MIP is an efficacious method to study and evaluate accessory renal arteries and in this study showed best performance compared with MPR and VR.

E253. Neoplastic and Non-neoplastic Disorders of the Perirenal Space Revisited: Imaging Findings with Pathological Correlation

Prasad S. R.²; Menias C. O.¹; Surabhi V.²; Dalrymple N. C.²; Narra V. R.¹; Humphrey P.³; Chintapalli K. N.² 1. Mallinckrodt Institute of Radiology, St. Louis, MO; 2. University of Texas HSC at San Antonio, San Antonio, TX; 3. Washington University, St. Louis, MO

Address correspondence to S. Prasad (prasads{at}uthscsa.edu)

Background: 1. To review the surgical anatomy of the perirenal space. 2. To discuss neoplastic and nonneoplastic conditions that localize to the perirenal space. 3. To discuss salient imaging findings of the broad spectrum of perirenal pathologies and to correlate with gross and histopathology

Key Issues: 1. Introduction. 2. Anatomy of the perirenal space. 3. Radiologic-pathologic correlation of the nonneoplastic conditions that involve the perinephric space - trauma, infection, extramedullary hematopoiesis, Erdheim-Chester disease, Castleman's disease. 4. Radiologic-pathologic correlation of the neoplasms that involve the perinephric space - lymphangioma, perirenal AML, RCC, lymphoma, liposarcoma. 5. Differential diagnoses and methods to distinguish various entities.

Format: Didactic by imaging with pathologic correlation

Teaching Points: A wide spectrum of neoplastic and nonneoplastic diseases may occur in the perirenal space. Perirenal space disorders may either arise from the kidney/adrenal or surrounding mesenchyme. Retroperitoneal diseases may also extend to the perirenal space either by lymphatic or contiguous spread. In this exhibit, we review the normal anatomy of the perirenal space and discuss the disease processes that are located in the perirenal space. Salient imaging findings of various conditions are discussed.

E254. Nonfatty Renal Masses in Patients with Lymphangioleiomyomatosis (LAM): Diagnosis and Management

Avila N. A.³; Dwyer A. J.³; Rabel A.¹; Pinto P.²; Moss J.¹ 1. Pulmonary-Critical Care Medicine Branch, NHLBI, Bethesda, MD; 2. Urological Oncology Branch, NCI, Bethesda, MD; 3. Warren G. Magnuson Clinical Center, Diagnostic Radiology Department, Bethesda, MD

Address correspondence to N. Avila (navila{at}nih.gov)

Objective: Patients with lymphangioleiomyomatosis (LAM) have an increased frequency of renal angiomyolipoma (AML) compared to the general population. Renal AMLs contain varying amounts of fat. The diagnosis of renal AML is made confidently when the mass contains fat on CT. However, some renal AMLs contain little or no fat, making the diagnosis more difficult to secure. We evaluated the frequency and CT imaging characteristics of nonfatty renal masses and correlated them with biopsy and long term follow-up findings in patients with LAM.

Materials and Methods: 328 patients with LAM had CT at initial presentation to our institution and during follow-up visits (most at yearly intervals as per protocol). We evaluated the frequency of nonfatty renal masses, their imaging characteristics, and changes in volume (APxTRVxCC diameters) during follow-up. For the purpose of this analysis, lesions were considered benign if the diagnosis was proven by biopsy or if the lesion showed less than 20% increase in volume in a follow-up period of at least 2 years.

Results: 36/328 (11%) patients had nonfatty renal masses; of these, 23/36 patients fulfilled the entrance criteria in this study (had biopsy or at least 2 year follow-up). The 23 patients had 25 nonfatty masses; of these, 14/25 masses were solid, and 11/25 were complex. On noncontrast CT the solid masses were: hyperdense to the kidney in 10/14, and isodense to the kidney in 4/14. Six of 11 masses found to be complex after enhanced CT were homogeneous on nonenhanced CT. Follow-up ranged from 0–96 months (median 75 months). Growth (more than 20% increase in volume) over the follow-up period was seen in 4/11 complex masses and in none of the solid masses. All 4 growing masses were surgically removed and found to be renal cell cancers. Biopsies on 2 complex stable masses and 4 solid stable masses showed AML.

Conclusion: Nonfatty renal masses are detected by CT in 11% of patients with LAM. Most (21/25, 84%) are benign "radiologically atypical" AMLs. The risk of cancer is highest when the mass is heterogeneous (4/11, 36%) and lowest when the mass is homogeneous (0/14, 0%). Since these patients frequently are at high surgical risk due to their lung disease, close follow-up rather than immediate biopsy or excision is advised, when a nonfatty renal mass is discovered.

E255. Imaging of Infrequent Renal Tumors with Histopathologic Correlation

Bhatt S.²; Canacci A.¹; MacLennan G.¹; Dogra V.² 1. Case Western Reserve University, Cleveland, OH; 2. University of Rochester Medical Center, Rochester, NY

Address correspondence to S. Bhatt (shweta_bhatt{at}urmc.rochester.edu)

Background: Renal cell carcinoma is a common urologic malignant lesion in adults and accounts for about 80% of renal tumors. But every renal mass detected on imaging is not a renal cell carcinoma. Uncommon renal tumors account for the remaining 20% of renal tumors and must be considered in the differential diagnosis. Understanding the imaging features of these uncommon tumors with their pathological correlation may help to make a more accurate diagnosis.

Key Issues: The objective of this exhibit is to demonstrate cross-sectional imaging features of uncommon renal tumors with their radio-pathological correlation. This presentation will include uncommon benign and malignant lesions such as collecting duct carcinoma, medullary carcinoma, juxtaglomerular tumor, oncocytoma, leiomyoma, fibrous histiocytoma, cystic nephroblastoma, lymphoma, renal plasmacytoma and other rare tumors.

Format: Didactic poster presentation with images showing characteristic diagnostic and pathological appearances.

Teaching Points: The attendee will be able to: 1. Describe and understand distinctive features of uncommon renal tumors enabling him to generate a reasonable differential diagnosis. 2. Describe the pathological basis of cross-sectional imaging of infrequent renal tumors.

E256. Frequency of Exclusionary Radiographic Abnormalities in Potential Living Renal Donors: A Comparison of Computed Tomographic Angiography versus Intravenous Pyelography and Renal Arteriography

Lockhart M. E.; Strang A. M.; Amling C. L.; Kenney P. J.; Morgan D. E.; Kolettis P. N. University of Alabama at Birmingham, Birmingham, AL

Address correspondence to M. Lockhart (mlockhart{at}uabmc.edu)

Background: Screening for potential renal donors ensures that no harm is done to the donor by nephrectomy and that the donated kidney is suitable anatomically. Previously, screening for living renal donation (LRD) included intravenous pyelography, Technetium Mag3 renal scan, and catheter angiography. At most large transplant centers, the screening of renal LRD patients is now performed with computed tomography utilizing pre IV contrast images, CT angiography, nephrographic, and excretory phase images, also known as CT urography (CTU).

Key Issues: The findings that result in donor rejection vary among transplant programs, and CT detects more of these abnormalities than traditional work-up. In 2005, 298 renal transplants, 169 from LRD, were performed at our institution. We recently evaluated the renal LRD rejection rate calculated over a one year period using older screening tests versus CTU, and found an increase from 20/272 (7.4%) to 53/333 (15.9%). Factors that led to this doubling of rejection of potential donors included increased detection of small renal calculi and subcentimeter renal masses that are incompletely characterized on CT. The purpose of this exhibit is to demonstrate the specific types of abnormalities detected with newer CT screening methods that lead to renal LRD rejection at our institution.

Format: The exhibit will use a didactic format. The concepts of renal donor evaluation and normal findings will be followed by specific examples of pathology that limit or prevent renal donation. Currently unresolved issues will also be addressed.

Teaching Points: This exhibit will review the techniques of CT/CTU for evaluation of potential renal donors and the associated increase in abnormal findings. It will address the variety of specific CT findings that lead to exclusion of the patient from donation.

E257. Adrenal Adenoma: MRI Quantitative Indices

EL-Merhi F.; Surabhi V.; Chintapalli K. N.; Dalrymple N.; Day C. UTHSCSA, San Antonio, TX

Address correspondence to F. EL-Merhi