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ABSTRACT |
Nguyen T.T.1; Escobedo E.1; Hunter J.1; Buonocore M.1; 1. Radiology, UC Davis Medical Center, Sacramento, CA.
Address correspondence to T.T. Nguyen (tomtnt74{at}comcast.net)
Background: Injuries to the rotator cuff and glenoid labrum are common and contribute to various symptoms from pain to instability. The shoulder can be imaged with sonography, CT, conventional MR, and direct and in-direct MR arthrography. Imaging with MR have conventionally been obtained in the standard axial, oblique coronal, and oblique sagittal planes to optimize visualization of the rotator cuff. However, due to the oblique course of the rotator cuff muscles and the ovoid, curved surface of the labrum, these structures can be difficult to fully visualize. Radial sequence MR imaging has been routinely and successful used in the imaging of the acetabular labrum. We propose that this additional imaging plane can be used for imaging of the rotator cuff and glenoid labrum to better visualize and identify pathology within these structures.
Key Issues: Direct MR arthrography is performed at our institution for the evaluation of the shoulder. The rotator cuff and glenoid labrum are evaluated using imaging sequences in the conventional axial, coronal, and sagittal planes and in conjunction with the radial sequence. The radial images provide orthogonal slices through the entire rotator cuff and labroligamentous complex. This results in improved visualization of these structures and increased conspicuity of injuries. The radial sequence can thus improve readers' confidence in the diagnosis of labral and rotator cuff tears and may allow for shorter imaging time by eliminating other sequences.
Format: The exhibit will be a didactic and interactive demonstration of the radial sequence for imaging of the shoulder. This will be an interactive PowerPoint presentation. It will include a brief review of the relevant anatomy followed by a demonstration of how the radial sequence's imaging planes are obtained. Subsequent sections will demonstrate various types of labral and rotator cuff injuries that are visualized with this sequence.
Teaching Points: 1) Learn a new MR sequence imaging plane for assessing the rotator cuff and labrum. 2) Learn the relevant anatomy and pathology of the rotator cuff and labroligamentous complex as visualized on the radial sequence. 3) Understand the value of radial imaging planes in the imaging of the rotator cuff and labrum.
E221. The Acute Knee Dislocation Checklist: A Systematic Approach to Complex and Often Devastating Injury Patterns
Robertson M.B.; Oostveen R.J.; Wissman R.D.; Kreeger M.C.; Verma S.M.; Radiology, University of Cincinnati, Cincinnati, OH.
Address correspondence to M.B. Robertson (mikerobertson67{at}yahoo.com)
Background: Acute knee dislocations are uncommon injuries which are often related to significant trauma. The spectrum of injury can range from lateral patellar dislocation to complete knee dislocations. There can be variable involvement of all three knee articulations: patellofemoral, tibiofemoral, and tibiofibular. Knee dislocations have high association of not only ACL and PCL tears, but additional soft tissue complications such as popliteal artery and peroneal nerve injuries. Ultimately, most knee dislocations may result in multidirectional instability without proper treatment.
Key Issues: Diagnostic imaging plays a key role in the evaluation of patients with knee dislocations. The superior soft tissue contrast of MR imaging is essential for evaluationof these injuries, and is often utilized to direct the scope and timing of surgical intervention. The exhibit will address the MRI findings of acute knee dislocations.
Format: This exhibit will present a concise, systematic approach to the evaluation of the dislocated knee. Specific anatomic detail and injury patterns of the three knee articulations (patellofemoral, tibiofemoral, and tibiofibular) will be addressed. Associated vascular and nerve injuries will be discussed. MR imaging will provide examples of each specific injury pattern.
Teaching Points: The viewer will: (1) Learn a systematic approach to the evaluation of the acutely dislocated knee. (2) Identify the common MRI findings and injury patterns associated with knee dislocations.
E222. Rotator Cuff Tendon Repair: Normal and Abnormal Ultrasound Findings
Brandon C.J.; Xerogeanes J.; Radiology, Emory University, Atlanta, GA.
Address correspondence to C.J. Brandon (catherine.brandon{at}emoryhealthcare.org)
Background: MRI has become the preferred imaging method for the shoulder but post-operative artifact can limit evaluation of the rotator cuff repair if metallic suture anchors or some types of absorbable anchors are used. When clinical findings suggests failure of the rotator cuff repair, familiarity with the ultrasound appearance of normal and abnormal post-operative findings can aid in diagnosis of the type and extent of failure at the repair site and direct additional surgical planning.
Key Issues: The normal ultrasound appearances of the rotator cuff are altered by tendon tear and the placement of the suture anchors. Comparison will be made between normal non-operative cuff tendons and uncomplicated post-operative ultrasound examinations. These cases will demonstrate some of the expected changes at the site of repair with the appearance of several different types of suture anchors into the humeral head. Then examinations showing such postoperative complications as full thickness retear, dislodged rotator cuff anchors and poor quality tendon tissue will be reviewed. Surgical correlation will be provided and when available, intra-operative photography shown. Instructions on how to scan the post-operative shoulder will be given with photographs of transducer placement on the post-operative patient.
Format: Didactic, with comparison among normal non-operative, uncomplicated post-operative, and problematic post-operative rotator cuff tendon repair patients. Correlation will be made with surgical follow-up and intra-operative photography when available.
Teaching Points: To recognize the expected alterations associated with rotator cuff tendon repair and to diagnosis some of the common complications seen with ultrasound.
E223. MRI Appearance of Upper Extremity Stress Response in the Throwing Athlete
Ferguson E.J.; Zoga A.C.; Avert M.; Morrison W.B.; Musculoskeletal/Radiology, Thomas Jefferson, Philadelphia, PA.
Address correspondence to E.J. Ferguson (ixrayi{at}hotmail.com)
Background: Stress fractures most commonly occur in the lower extremity or pelvis, often involving the femur, tibia and metatarsals. In contrast, stress fractures in the upper extremity are relatively rare. Recently, a pattern of humeral stress response in the overhead throwing athlete has been well described in the orthopedic surgery and sports medicine literature.(1) Both overhead and underhand throwing sports, racquet sports, gymnastics, and even hand grenade tossing in military recruits are activities which generate tremendous torque forces across the long bones of the upper extremity that can result in stress response and even stress fractures.(4) We present a series of throwing athletes with abnormal MRI findings in the long bones of the upper extremity likely reflecting these extreme torque stresses.
Key Issues: All five of the overhead throwing athletes had a similar and almost identical pattern of bone marrow edema in the distal humeral diaphysis and metaphysis at the time of initial MRI. This marrow edema, T2 hyperintense and T1 intermediate, was most prominent in the subcortical region, but extended into the medullary cavity in each case. In three of the five overhead throwers, humeral cortical thickening was noted at the distal diaphysis when compared to the proximal radius and ulna in the same extremity. There were no ligament injuries in any of these patients by MRI, and in only one case was abnormal signal in the elbow tendons identified, a pitcher with mild common flexor tendonitis. At follow-up, all patients showed improvement of humeral bone marrow edema. At 12 weeks, follow-up MRI demonstrated persistent subcortical and medullary bone marrow edema in the distal humerus, though medullary T2 hyperintensity had decreased, and marrow signal abnormality was less diffuse and more patchy.
Format: The findings will be presented in a poster presentation and organized by upper extremity/elbow, MR imaging, and as overuse injuries.
Teaching Points: The severity of findings on MR correlates can be a major determine in how each patient is best treated. There is a Grading system of stress response: Grade 0 is normal, Grade II is periosteal edema on T2WI, Grade III is periosteal edema and marrow edema on T2WI, Grade III is increased periosteal fluid and marrow edema seen on T1WI and T2WI, Grade IV is a discrete fracture line. This grading system described is used in an algorithm for triage and treatment of overuse injuries.
E224. Sonographic Evaluation of Acute Knee Pathology
Paulsen S.D.; Girish G.; Jacobson J.; Jamadar D.; Department of Radiology, University of Michigan, Ann Arbor, MI.
Address correspondence to S.D. Paulsen (spaulsen{at}umich.edu)
Background: In the setting of acute knee pathology, radiography is the first-line imaging modality but is limited in its usefulness for soft tissue injuries. MRI has proven utility in evaluating internal derangements and other soft tissue pathologies, but it is not always available in the acute setting and may be difficult or impossible to obtain in the severely ill or poly-trauma patient or because of contraindications. Sonography is cost-effective, portable, widely available, and optimized for evaluation of the soft-tissue structures of the knee. Where quick diagnosis is vital, sonography is an ideal imaging modality to guide subsequent treatment.
Key Issues: To present the spectrum of acute knee pathology imaged by sonography. To emphasize the advantages of sonography as an ideal imaging modality for acute knee pathology.
Format: This exhibit provides a pictorial review of acute knee pathologies readily imaged by sonography. The use of sonography to evaluate posterolateral corner injuries is emphasized. Examples of sonographic imaging of injuries to the extensor mechanism and the collateral ligaments, and of joint effusions and soft tissue infections are presented. The sensitivity of sonography in evaluating meniscal and cruciate ligament pathology is discussed.
Teaching Points: The combination of availability, resolution, and portability make sonography an ideal imaging modality for evaluation of the soft-tissue structures of the knee in the acute setting, particularly when early diagnosis and treatment is vital to reduce long-term morbidity.
E225. Complications of Musculoskeletal Infection
Beaman F.D.1; Bancroft L.W.1; Kayes A.V.1; Peterson J.J.1; Berquist T.H.1; Kransdorf M.J.1,2; 1. Radiology, Mayo Clinic, Jacksonville, FL; 2. Radiologic Pathology, Armed Forces Institute of Pathology, Washington, DC.
Address correspondence to F.D. Beaman (beaman.francesca{at}mayo.edu)
Background: Musculoskeletal infection may occur in a myriad of clinical settings including systemic infection or illness, blunt or penetrating trauma, or iatrogenic causes. Infection is both a primary complication and a medium through which deleterious effects may impact bone, muscle, neurovascular, and soft tissue environments as well as implanted materials. The understanding and treatment of infection has been extensively researched, yielding improvements in surgical techniques and advances in antibiotic therapy (i.e. antibiotic coated prostheses and local antibiotic delivery vehicles). Prompt diagnosis of infection remains essential in reducing patient morbidity and mortality, and preventing further complications. Imaging continues to play a key role in the characterization and diagnosis of complications of musculoskeletal infection.
Key Issues: 1. Sequelae of septic arthritis/disciitis (joint destruction, angulation, ankylosis); 2. Extension of infection (along tendon sheaths, nerves, muscles, other contiguous structures); 3. Tendon avulsion; 4. Devascularization (requiring amputation); 5. Reconstructed tendon graft (debridement, removal); 6. Musculocutaneous flap complications (a. placement for soft tissue coverage after infection or b. debridement, compromise, removal of existing flap); 7. Hardware failure (septic loosening, hardware fracture, dissociation, displacement, Girdlestone procedure, hardware removal, ankylosis); 8. Tumors (stump neuroma after amputation due to infection, squamous cell carcinoma).
Format: We will utilize a quiz format, and organize multiple case presentations by pathology. Each case presentation will engage the learner with a short history and pertinent images, utilizing various modalities. Imaging findings, differential diagnosis (when appropriate) and diagnosis will be solicited. Subsequently, the presentation will address each complication of infection and give relevant references.
Teaching Points: Following completion of this educational exhibit, participants will be able to define potential complications of musculoskeletal infection and recognize their associated imaging characteristics.
E226. Spectrum of Musculoskeletal Imaging Findings in HIV Infection
Chong-Han C.H.1,2; Chung C.B.1,2; Torshizy H.; Hughes T.H.1; 1. Radiology, UCSD Medical Center, San Diego, CA; 2. Radiology, Veterans Affairs San Diego Healthcare System, La Jolla, CA.
Address correspondence to C.H. Chong-Han (c_chonghan{at}yahoo.com)
Background: Since the early 1980's, human immunodeficiency virus (HIV) has grown to be a world-wide epidemic affecting approximately 40 million people. Destruction of normal T-cell lymphocytes allows opportunistic infections to invade the host's defenses. HIV also increases the host's susceptibility to immune-related neoplasms and inflammatory conditions. Although HIV more commonly affects the central nervous system and the respiratory system, varied presentations are encountered in the musculoskeletal system.
Key Issues: Infectious disease of the soft tissue and bones associated with AIDS include cellulitis, abscesses, fasciitis, pyomyositis, osteomyelitis, septic bursitis, septic arthritis, and bacillary angiomatosis. Causes include both pyogenic and mycobacterial organisms. Inflammatory conditions such as hoffitis, reiter's and psoriatic arthritis, AZT myopathy, and capsulitis are seen in the AIDS population. Immune related neoplasms in AIDs patients include Kaposi sarcoma and lymphoma. There are other miscellaneous entities of the musculoskeletal system connected with HIV infection such as osteonecrosis, rhabdomyolysis, hypertrophic osteopathy, and hypointense marrow.
Format: In our pictorial essay, we report the gamut of skeletal and soft tissue imaging findings related to infection with HIV. In addition to well-known musculoskeletal complications of AIDS, recently reported entities thought to be related to HIV such as hoffitis will be briefly discussed.
Teaching Points: Musculoskeletal manifestations of HIV encompasses a wide spectrum of disease ranging from infectious and inflammatory etiologies to neoplasm. Recognition of these entities is important in early diagnosis and treatment.
E227. Acetabular Fractures: Classification, Imaging and Management
Jayakumar J.; Yoon W.; Natali C.; Woo E.K.; Viney Z.; Alyas F.; Radiology, St. Thomas' Hospital, London, United Kingdom.
Address correspondence to J. Jayakumar (j.jayakumar{at}doctors.org.uk)
Background: Acetabular fractures are rare but pose complex reconstruction issues. This presentation will demonstrate the mechanisms of injury, classification, relevant imaging techniques and post-operative appearances.
Key Issues: A comprehensive description of the anatomy of the acetabulum, as well as the mechanism of injury of acetabular fractures will be presented. The imaging techniques will be discussed in detail, in particular the role of CT in pre-operative planning. The key points required for orthopaedic management will also be presented together with the latest surgical interventions.
Format: The presentation format will be a didactic PowerPoint presentation. Comparisons of normal anatomy and pelvic trauma will be presented together with a discussion of various imaging modalities and their unique advantages to the orthopaedic surgeon. The presentation will be organized according to the classification of acetabular fractures.
Teaching Points: The focus will be on clinical decision-making and management issues, based upon knowledge of the classification system of acetabular fractures and their typical radiological findings and important imaging pitfalls. The reader will gain a greater understanding of the surgical orthopaedic perspective and practical management issues related to acetabular fractures.
E228. Characterization of Acetabular Fractures: Computed Tomography with Surgical Correlation
Umphrey H.R.1; Matherne T.H.1; Lander P.H.1; Lopez R.R.1; Alonso J.E.2; 1. Department of Radiology, University of Alabama at Birmingham, Birmingham, AL; 2. Department of Orthopaedic Surgery, University of Alabama at Birmingham, Birmingham, AL.
Address correspondence to H.R. Umphrey (humphrey{at}uabmc.edu)
Background: In 1964, Letournel and Judet designed a conventional radiographic method for classifying acetabular fractures. Today, we routinely cross-sectionally image these patients, and reformat anatomy in 2D and 3D projections, for detail characterization and surgical planning. Multiple methods of classifying these fractures have been developed to correlate with cross-sectional imaging and to improve communication between radiologists and orthopedic/trauma surgeons.
Key Issues: We discuss and illustrate acetabular fracture interpretation using computed tomography with conventional radiographic and surgical correlation. We compare classification methods, based on published research and our experience at UAB.
Format: Didactic exhibit will review various imaging classifications. This will be followed by an illustrated method for cross-sectional characterization. Emphasis is on computed tomography and it's role in surgical planning and postoperative management.
Teaching Points: 1. Letournel and Judet's conventional radiographic classification of acetabular fractures created a landmark in advancement of treatment in this population of patients. Multiple methods have been designed to simplify this classification and correlate with computed tomography. 2. The goal of cross-sectional imaging is to describe major fracture orientation and characteristics that will negatively influence surgical reduction or increase postoperative complications. 3. Understanding of basic fracture mechanics, surgical goals, and possible complications will improve radiologic interpretation.
E229. Loss of Internal Rotation of the Hip Joint: Pathologic Processes and Image Differentiation of the Etiology of the Range of Motion Limitation
Beall D.P.1,2; Martin H.D.1; Costello R.F.1; Ly J.Q.3; 1. Department of Radiology, Oklahoma Sports Science and Orthopedics, Oklahoma City, OK; 2. Department of Radiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; 3. Department of Radiology and Nuclear Medicine, Wilford Hall Medical Center, Lackland AFB, TX.
Address correspondence to D.P. Beall (dpd{at}okss.com)
Background: Loss of internal rotation of the hip is seen in a variety of disorders that may be divided into osseous, ligamentous and tendinous etiologies.
Key Issues: The primary osseous disorder is osteoarthritis but femoroacetabular impingement, femoral retroversion and decreased acetabular anteversion may also contribute to loss of internal rotation. Soft tissue impingement occurs when the iliopsoas tendon and the iliofemoral ligament obstruct internal rotation. Contracted ligaments (iliofemoral and ischiofemoral ligament) and muscles (piriformis, iliopsoas, gluteus medius, and gluteus maximus) may also decrease motion and loss of rotation may also occur with direct obstruction due to loose bodies or osteochondromatosis. All of these entities may cause similar physical exam findings but are very different processes and require different treatments.
Format: Didactic with MR and plain film radiography.
Teaching Points: Imaging identification of the etiology of the loss of internal rotation is an effective way to locate the abnormality and facilitate appropriate treatment.
E230. Rules, Clues and Tips in Differentiating the Infected and the Non-Infected Charcot Foot on MRI.
Moore S.L.2; Schweitzer M.E.1; 1. Radiology, NYU Medical Center, New York, NY; 2. Radiology, Hospital for Joint Diseases, New York, NY.
Address correspondence to S.L. Moore (sandra.moore{at}nyumc.org)
Background: A patient with neuropathy may be referred to imaging for a swollen foot with concern for acute Charcot, or for pedal Charcot with ulcer formation. The radiologist is asked to exclude infection. Although the clinical presentation may militate for or against infection, the radiologist may not have the benefit of physical exam and thorough history. If there is pedal collapse and ulceration, the clinical presentation may be ambiguous, and accurate MRI interpretation is critical. Overlapping MRI findings of non-infected and infected pedal Charcot complicate differentiation; these include fluid collections, bony debris, and marrow edema, +/- enhancement. Radiologists often lack diagnostic confidence in differentiating these difficult cases and "overcall" osteomyelitis out of caution, but as these patients often have impaired healing or are poor surgical candidates, we should strive to avoid false positive calls. The purpose of our education exhibit is to discuss and illustrate the rules, clues and tips that aid diagnostic confidence.
Key Issues: We demonstrate the characteristic sites and probabilities of infection for Charcot changes vs. infection in the foot. Charcot usually occurs in the midfoot where infection (excepting rockerbottom ulcer) is rare, and infection often occurs at the toes/MTP joints where neuropathic change is rare. Associated findings that militate for infection (e.g. adjacent ulcer, tract, abscess) will be illustrated. Charcot changes are joint centered, whereas osteomyelitis is bone centered, rarely involving a multiplicity of bones. Findings that militate against infection will be illustrated, e.g., subchondral cysts, and the "ghost" sign of neuropathic marrow edema. In most cases, we adhere to the dictum: NO ULCER, NO OSTEOMYELITIS. Ulcers occur in predictable locations based on the dibility of the patient and adjacent neuropathic change and are usually situated directly over the rocker-bottom exostosis. Understanding the patterns of pedal collapse and the associated "rocker" patterns directs attention to the likely site of osseous infection, and aids in the search for ulcer, or incipient ulcer.
Format: The anatomic/pathologic findings will be illustrated on MR and X-ray images, with relevant text.
Teaching Points: The viewer will learn the sites/probabilities of infection in the Charcot foot, the patterns of pedal collapse and associated rocker deformity categories, and will learn specific findings that militate for or against infection.
E231. MRI of Traumatic Elbow Fractures
Mortezaie A.; Radiology, University of Southern California, Los Angeles, CA.
Address correspondence to A. Mortezaie (mortezai{at}usc.edu)
Background: The elbow is a complex anatomical structure combining the humerus, radius, and ulna in a highly functional arrangement. Stabilizing structures are the lateral collateral (LCL), medial collateral (MCL), ulnar collateral, radial collateral, and annular ligaments. Along with overlying muscles and tendons, these bones and ligaments are susceptible to injury, especially during vehicular accidents and falls. MRI is often useful in detecting fractures and ligamentous injuries. The ability of MRI to identify elbow injuries can be limited by the arm position when the patient's arm is casted in functional flexion. We previously studied the ability of MRI to identify the elbow ligaments when the arm is scanned in a non-standard position. By using cadaveric elbows, we were able to determine which elbow positions offered optimal MRI recognition of several structures, including the LCL and MCL. In the present educational exhibit, we review the MRI anatomy of the elbow with cadaveric correlation, discuss the technical limitations of elbow MRI, and demonstrate multiple cases of traumatic elbow fractures and their associated ligamentous and soft tissue injuries.
Key Issues: From a database of MRI studies performed since 2000, we retrieved 28 elbow MRIs in patients with traumatic elbow fractures. We examined these images of the elbow acquired at multiple views including coronal, sagittal, axial, and oblique coronal planes. Each fracture was characterized by anatomic location and whether there were any associated ligamentous injuries. Of these 28 cases, there were 20 radial head fractures, 7 coronoid fractures, 3 lateral epicondylar fractures, and 2 medial epicondylar fractures. In addition, we identified 7 ulnar collateral ligament, 7 radial collateral ligament, 3 medial collateral ligament, and 3 lateral collateral ligament injuries. Intermediate oblique coronal views demonstrated collateral ligaments optimally.
Format: This is a didactic presentation emphasizing current technical considerations of elbow MRI, normal MRI elbow anatomy, and MRI findings of traumatic fractures of the elbow. Images of several types of elbow fractures and associated injuries are shown.
Teaching Points: The viewer will learn: 1. To optimize technical considerations and current methods of elbow MRI. 2. The normal anatomy of the elbow as demonstrated by MRI. 3. The MRI characteristics of elbow fractures and soft tissue injury with clinical presentations and correlative imaging findings.
E232. MRI of Calf Pain in Elite Athletes
Johnston C.; Ford S.; Eustace S.; Radiology, Cappagh National Orthopedic Hospital, Dublin, Ireland.
Address correspondence to C. Johnston (ciaranjohnston{at}yahoo.co.uk)
Background: Calf pain in high performance athletes is relatively common entity with a wide differential diagnosis. History and clinical examination are invaluable, but symptoms often overlap and examination may be limited by pain. In this setting, MRI provides an excellent non-invasive assessment and may be used in the characterization of an injury and to provide valuable information regarding prognosis and return to activity.
Key Issues: We will focus on reviewing the MR imaging findings of common causes of calf pain in high performance athletes. This is important as the MR evaluation of athletic injuries to the knee and ankle have been well described, but less so for calf injuries. Relevant anatomy is reviewed, with special reference to compartmental anatomy, and vascular and nerve supply. Images were performed at 1.5T with a 25cm FOV and a phased array coil. Coronal and axial T1 weighted and STIR images were acquired. Additional sequences were performed according to the clinical question, including post exercise images for compartment syndrome.
Format: The presentation will take a didactic format in which the different causes of calf pain in athletes will be demonstrated. These will be divided according to the anatomical structure involved (muscles: strain, contusion, tear, intramuscular hematoma, muscle hernia; osseous structures: stress fracture, medial tibial stress syndrome, interosseous membrane rupture, tibiofibular joint ganglion; vascular causes: acute and chronic compartment syndrome, cystic adventitial necrosis, intimal fibrosis; neurogenic causes: schwannoma).
Teaching Points: Calf pain is common in high performance athletes and is under diagnosed. Familiarization with the different causes of calf pain in athletes and their differentiation with MRI enables the radiologist to offer both a diagnostic and prognostic opinion to referring clinicians.
E233. Teres Minor Tendon Tears: MR Imaging and Clinical Implications
Shetty M.; Yadavalli S.; Khan F.; Wiater J.M.; Fessell D.P.; Diagnostic Radiology, William Beaumont Hospital, Royal Oak, MI.
Address correspondence to M. Shetty (monishashetty1{at}hotmail.com)
Objective: The purpose of this study is to define the incidence of teres minor tendon tears noted at surgery, to describe their appearance and association with other tears of the rotator cuff and to review the clinical significance of teres minor tendon tears, including their importance with reverse glenohumeral joint arthroplasty.
Materials and Methods: Four hundred and three operative reports of shoulder surgery performed over a fifteen-month period by one orthopedic surgeon specializing in the shoulder were reviewed. Fourteen of these operative reports described teres minor tendon tears and one report described a teres minor muscle tear. All fourteen cases of teres minor tendon tear also had tears of both the supraspinatus and infraspinatus tendons. Five of the fourteen cases had undergone pre-operative MRI imaging. The pre-operative MRI studies of these patients were retrospectively reviewed and the optimal sequences, imaging planes and relevant anatomy were noted.
Results: Retrospective review of the MRI images of surgically-proven teres minor tendon tears revealed tears of both the supraspinatus and infraspinatus tendons in all cases of teres minor tendon tear. One case of teres minor muscle tear was noted in the setting of posterior shoulder dislocation.
Conclusion: The integrity of the teres minor tendon plays an important role in clinical outcome. An intact teres minor tendon can significantly contribute to activities of daily living such as eating and drinking. Increasingly, studies indicate that repairs of massive tears of the rotator cuff are being performed and can result in good clinical outcome. The integrity of the teres minor tendon can be difficult to assess clinically and is particularly important for good functional outcome in cases of reverse shoulder arthroplasty.
E234. MDCT Assessment of the Cruciate Ligaments with MRI Correlation
Mustonen A.O.1; Koivikko M.P.1; Haapamaki V.V.1; Kiuru M.J.1,3; Lamminen A.E.2; Koskinen S.K.1; 1. Radiology, Toolo Trauma Center, Helsinki, Finland; 2. Radiology, Meilahti Hospital, Helsinki, Finland; 3. Radiology, Orton Hospital, Helsinki, Finland.
Address correspondence to A.O. Mustonen (antti.mustonen{at}hus.fi)
Objective: To evaluate the diagnostic potential of MDCT in assessing cruciate ligament pathology in acute knee injury.
Materials and Methods: 42 patients (17-65 years) with an acute knee injury had a 4-channel MDCT examination of the knee. No contrast material was used. The images were independently evaluated at clinical PACS workstations by 4 radiologists having 1-15 years subspecialty experience in musculoskeletal radiology, who were blinded to the patients' clinical history. They assessed the integrity (normal/torn) and the best plane (axial, sagittal or coronal) for visualization of the cruciate ligaments. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy in addition to inter-observer and intra-observer differences were assessed. Cases were evaluated twice with at least 4 weeks separating the reading sessions. MRI, performed within 4 weeks from the injury, was regarded as the gold standard.
Results: Ligament integrity at MDCT: mean inter-observer proportion of agreement was 0.73 for normal and 0.41 for a torn ACL, and 0.96 for normal and 0.54 for a torn PCL. Inter-observer variation for the ACL was significant (p < 0.05), but insignificant (p > 0.05) for the PCL. Intra-observer variation was insignificant. Visualization was the best in the axial (p = 0.0224) and sagittal (p = 0.0168) plane for the ACL and PCL, respectively. At MRI, 29 normal, 1 partial tear, and 12 completely torn ACLs; 37 normal, 4 partial tears, and 1 completely torn PCL were found. Correlation with MRI: mean inter-observer proportion of agreement was 0.73 for normal and 0.36 for a torn ACL, and 0.93 for normal and 0.35 for a torn PCL, respectively. Mean sensitivity for ACL abnormality was 0.58 (range 0.25-0.92), specificity 0.87 (range 0.68-0.96), accuracy 0.78 (range 0.68-0.86), PPV 0.67 (range 0.45-0.86), and NPV 0.84 (range 0.73-0.96). For PCL abnormality mean sensitivity was 0.25 (range 0.20-0.40), specificity 0.97 (range 0.94-1.00), accuracy 0.88 (range 0.85-0.90), PPV 0.55 (range 0.33-1.00), and NPV 0.90 (range 0.89-0.92). The length of the observers' experience did not affect the results.
Conclusion: MDCT was able to detect the intact ACL and PCL with good specificity and accuracy. Assessment of torn ligaments was not reliable. The method is equally suitable for a junior radiologist. MDCT of the cruciate ligaments yields a good negative predictive value.
E235. MR Imaging Findings of Medial Meniscal Root Tear: Type of Tear and Relationship With Other Associated Findings
Shim J.1; Kim J.2; Seo M.1; Gwon D.1; Lee G.1; Kim H.1; 1. Diagnostic Radiology, Inje University Seoul Paik Hospital, Seoul, South Korea; 2. Orthopedic Surgery, Inje University Seoul Paik Hospital, Seoul, South Korea.
Address correspondence to J. Shim (promind{at}lycos.co.kr)
Objective: To demonstrate MR findings of medial meniscal root tear which is arthroscopically repairable.
Materials and Methods: Thirty seven knees of 36 patients, diagnosed as medial meniscal root tear on the clinical evaluation and MRI, were included in the study. They were 7 men and 29 women with an average age of 60 years (age range, 44-77 years). Arthroscopic surgery was done in 28 knees including repair of 25 medial meniscal root tears by pull-out technique. We evaluated the type of tear and the relationship with the other associated findings on MR imaging and correlated them with the arthroscopic findings in the surgical cases.
Results: MRI demonstrated radial tear in all cases demonstrating vertical linear defect on coronal images, loss of shape and signal intensity on sagittal images, and radial linear defect on axial images. MR imaging findings corresponded with the arthroscopic findings in all surgical cases. Root tears could be seen on coronal and sagittal images in all cases and on axial images in 35 of 37 cases. Coronal and axial images were useful for the demonstration of the exact location. Among the other associated findings, degenerative joint disease and medial meniscal horizontal tears were demonstrated in 92% (34/37) and 41% (15/37).
Conclusion: MR imaging is accurate in the diagnosis of medial meniscal root tear. Medial meniscal root tear is significantly associated with degenerative joint disease.
E236. Utility of Follow-up Magnetic Resonance Imaging of Osteomyelitis of the Foot
McWilliams J.1,2; Freitas A.D.2; Masih S.1,2; 1. Radiology, University of California at Los Angeles (UCLA), Los Angeles, CA; 2. Imaging, West Los Angeles VA, Los Angeles, CA.
Address correspondence to J. McWilliams (Jmcwilliams{at}mednet.ucla.edu)
Objective: To determine the utility of and proper interval for, re-imaging a patient with clinically diagnosed osteomyelitis of the foot for the purpose of monitoring treatment.
Materials and Methods: We retrospectively reviewed the last five years of foot MRI scans that were obtained for the purposes of monitoring treatment. All patients had baseline MRI scans at the start of treatment and were clinically diagnosed with osteomyelitis. Baseline and follow-up scans were reviewed by 2 musculoskeletal radiologists and a radiology resident for evidence of change. The interval between scans was noted.
Results: Follow-up MRI scans were obtained on patients who both were and were not showing desired improvement in their clinical course. Preliminary results demonstrate little improvement in the MR appearance in follow-up scans of the foot if obtained before six weeks since the baseline examination, although many showed worsening. Beyond six weeks, several cases demonstrate partial or complete resolution of abnormal bone marrow signal. Others demonstrated improvement of abnormal signal in the initial site but developed abnormal signal in a second site.
Conclusion: Repeat MRI scans of the foot for monitoring treatment of osteomyelitis are particularly useful for patients not showing clinical improvement, to help confirm the clinician's suspicions and to help guide further treatment, including possible amputation. In patients showing clinical improvement, MRI scans to monitor therapy should be obtained no earlier than approximately six weeks after the baseline study. (These findings serve as an important background for a prospective protocol to determine what MRI findings can be expected in all patients being treated for osteomyelitis of the foot).
E237. Do the MR findings of ACJ Osteoarthritis Correlate with a Positive Clinical Exam?
Edelstein Y.1; Schweitzer M.E.2; Cunningham P.M.3; Babb J.S.2; Sherman O.H.2; 1. Radiology, SUNY Health Science Center at Brooklyn, Brooklyn, NY; 2. Radiology, Hospital for Joint Disease/NYU, New York, NY; 3. Radiology, Harlem Hospital, New York, NY.
Address correspondence to Y. Edelstein (yudell.edelstein{at}downstate.edu)
Objective: Abnormalities about the acromioclavicular joint (ACJ) are seen on shoulder MR relatively frequently. Since symptoms in this area are uncommon, we sought to systematically determine which MR findings correlate with a positive clinical examination.
Materials and Methods: At 1.5 T 43 patients were evaluated. Their imaging studies consisted of 3 plane proton density and fluid weighted sequences. All patients had a detailed physical exam performed by a single sports medicine orthopedic surgeon. An analysis was performed by two independent readers blinded to the clinical exam, for:1. clavicular geode. 2. clavicular marrow edema. 3. clavicular osteophytes - superior. 4. clavicular osteophytes - inferior. 5. acromial geodes. 6. acromial marrow edema. 7. acromial osteophytes superior. 8. acromial osteophytes inferior. 9. joint effusion. 10. capsule hypertrophy superior. 11. capsule hypertrophy inferior. 12. periarticular soft tissue edema - superior. 13. periarticular soft tissue swelling - inferior. 14. Visible meniscus. These findings were graded on a scale from 1-3, except for the meniscus, which was graded absent or present.
Results: Weighted kappa statistics were used to assess interobserver agreement. Generalized estimating equations (GEE) based on a binary logistic regression model were used to assess the utility of individual reader assessments, and binary logistic regression (BLR) was used to assess the utility of the average reader assessment, for the diagnosis of a positive physical exam. The p values for GEE and BLR, and weighted kappa statistics for each finding, respectively, were as follows: clavicle geode (.200) (.136) (.289), clavicle edema (.049)(.019)(.631) clavicle osteophytes superior (.289)(.222)(.241) clavicle osteophytes inferior (.683)(.578)(.283) acromial geode (.439)(.456)(.511) acromial edema (.293) (.302)(.592) acromial osteophyte superior (.882)(.767)(.296) acromial osteophyte inferior (.388)(.265)(.428) joint effusion (.489)(.381)(.322) capsule hypertrophy superior (.231)(.156)(.451) capsule hypertrophy inferior (.108)(.043)(.415) periarticular soft tissue edema superior (.709)(.707)(-.096) periarticular soft tissue edema inferior (.028)(.005)(.263) meniscus (.455)(.432)(-.042). Clavicle edema, inferior capsule hypertrophy, and inferior periarticular edema correlated with ACJ symptoms. Interobserver agreement was good only for clavicle edema.
Conclusion: Clavicle edema, inferior capsule hypertrophy and inferior periarticular soft tissue edema correlates with ACJ symptoms.
E238. MR of Recurrent SLAP Lesion; The Value of Primary vs. Secondary Signs
Birnbaum M.D.; Schweitzer M.E.; Zoga A.; Musculoskeletal Radiology, NYU School of Medicine, New York, NY.
Objective: In current orthopedic thinking, the pre-operative imaging evaluation of labral tears is becoming less important with advances in shoulder arthroscopy. Concomitant with this, the diagnosis of recurrent labral tears by imaging is becoming increasingly important. Consequently, we chose to study the accuracy of MR for recurrent SLAP lesions.
Materials and Methods: 38 patients were identified with possible SLAP tears. Each patient had an MR prior to second look shoulder surgery or clinical confirmation which were retrospectively reviewed by two observers, M.E.S and E.A, for secondary signs including internal signal on T1 or T2, excess fluid, rotator cuff tear, axial separation of the labrum, biceps tendinosis, and biceps tear. A detailed physical exam or repeat surgery was used to confirm the presence or absence of a labral tear.
Results: There were 15 post operative shoulders evaluated for SLAP tear. The presence or absence of a SLAP tear was determined by surgical or clinical confirmation; 8 surgically confirmed and 7 clinically confirmed. The overall accuracy of MR was 87% (sensitivity 90%, specificity 80%, PPV 90%, NPV 80%). MR arthrography and nonenhanced MR imaging had accuracies of 90% and 80% respectively; thus there is a trend for MR arthrography to be better than non-contrast MR. MR arthrography was more specific, 100% vs. 67%, but less sensitive, 88% versus 100% than nonenhanced MR imaging in depicting recurrent SLAP tears. The best signs for retear were internal signal on T1 and T2, excessive fluid, and biceps tendon tear.
Conclusion: MR, not surprisingly, is somewhat less accurate for recurrent SLAP than reported for virgin shoulders: secondary signs such as internal signal on T1 or T2, excessive fluid and biceps tendon tear may help improve accuracy.
E239. Partially Torn Posterior Cruciate Ligament Causing Medial Tibiofemoral Joint Impingement in the Knee: Correlation of MR Images with Arthroscopic Findings
Kwon S.T.1; Kim Y.M.2; Song C.J.1; Kim J.H.1; Yoon C.D.1; Rhee K.J.2; 1. Diagnostic Radiology, Chungnam National University Hospital, Daejeon, South Korea; 2. Orthopaedic Surgery, Chungnam National University Hospital, Daejeon, South Korea.
Address correspondence to S.T. Kwon (stkwon{at}cnu.ac.kr)
Objective: To demonstrate the MR imaging features of partially torn posterior cruciate ligament (PCL) causing medial tibiofemoral joint impingement (MTFI) and correlate with arthroscopic findings.
Materials and Methods: MR images in 13 patients (5 women, 8 men; age range, 25-62 years; mean age, 45 years) with arthroscopically proven partial PCL tears and impingement in the medial tibiofemoral joint. MR imaging was obtained with a routine protocol using a 1.5T MR unit. The location and features of the each band of the PCL tear, the best plane for the diagnosis of the partial PCL tear including any associated findings, were assessed.
Results: The location of the partial tear was as follows: partial femoral avulsion of the PCL, 12 cases (92%); middle substance, one case (8%). 11 cases (85%) present a partial or near total tear of the posteromedial band (PMB) of PCL. Two cases (13%) present near total tear (grade 2-3) of the both PMB and anterolateral bundle. The direct finding of the MTFI on MRI was partial detachment and a redundant stump of the PMB of PCL intervening in a tibiofemoral joint. These findings were detectable in coronal (n = 13, 100%), axial (n = 6, 46%), and sagittal (n = 5, 39%) images, respectively. Associated findings were loss of fatty signal intensity of the inferior PCL fat pad on T1WI (n = 10, 77%) and band-like low signal intensity at the inferior aspect of PCL on coronal images (n = 3. 23%).
Conclusion: MR imaging allows well assessment of the features of partially torn PCL causing MTFI and well correlated with arthroscopic findings. The almost tear was femoral attachment site of the PMB of PCL. The Intervening of the redundant stump of PMB in the medial tibiofemoral joint was best visualized on coronal images.
E240. The Role of Magnetic Resonance Imaging in the Diagnosis of Chronic Exertional Compartment Syndrome
Omar H.A.1; Helms C.A.1; Bytomski J.2; Toth A.3; 1. Radiology, Duke University Medical Center, Durham, NC; 2. Community and Family Medicine, Duke University Medical Center, Durham, NC; 3. Orthopaedic Surgery, Duke University Medical Center, Durham, NC.
Address correspondence to H.A. Omar (hosas26{at}hotmail.com)
Objective: First described by Volkmann in 1881 in its acute form, chronic exertional compartment syndrome (CECS) represents an overuse condition of exercise-induced pain affecting primarily active individuals. Traditionally, the diagnosis of CECS was suggested by history and physical exam and confirmed objectively by intramuscular pressure measurements before and after exercise. The role of magnetic resonance imaging (MRI) as a noninvasive objective alternative in establishing the diagnosis of CECS has been explored but not firmly established. The objective of this study was to define the imaging characteristics and role of MRI in the diagnosis of CECS.
Materials and Methods: Patients suspected of having CECS on clinical grounds underwent post-exercise MRI. Patients were exercised to reproduce clinical symptoms prior to imaging. T1 and fast STIR sequences were acquired in axial and coronal planes on a 1.5T magnet. Correlation with clinical history and post-imaging intramuscular pressure measurements following similar exercise was performed.
Results: Overall, 6 patients were referred for MRI. In each case, the asymptomatic extremity served as the control. Close correlation was attained in all patients with MR revealing increased STIR signal in compartments proven to have elevated pressures.
Conclusion: This study validates the use of MRI as a legitimate, objective, noninvasive alternative to the traditional painful and invasive means of diagnosis of CECS.
E241. Assessment of MR Imaging with Superparamagnetic iron Oxide Particles in Infectious Disease of the Joint or Soft Tissue of Rats
Lee SM.1; Lee SH.2; Kang HY.3; Baek SY.4; Kim SM.2; Ha DH.1; Shin MJ.2; 1. Diagnostic Radiology, Bundang CHA General Hospital, College of Medicine, Pochon CHA University, Sungnam, South Korea; 2. Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea; 3. Pathology, Bundang CHA General Hospital, College of Medicine, Pochon CHA University, Sungnam, South Korea; 4. Diagnostic Radiology, Ewha Woman's University Mokdong Hospital, Seoul, South Korea.
Address correspondence to S.M. Lee (drsmlee{at}chol.com)
Objective: The purpose of this study is to evaluate the usefulness of SPIO-enhanced MRI in experimental models of infectious disease and to analysis the intracellular uptake of SPIO.
Materials and Methods: Nine rats with infectious arthritis of knee or soft tissue infection were imaged with an MRI unit on days 4-6 after intravenous injection of the S. aureus suspension. All animals were imaged on T2-weighted TSE sequence prior to and 24 hour after administration of SPIO. Nine rats were classified as two groups according to the dose of SPIO; 6 of low to intermediate dose (3-60 mol Fe/300 g body weight) and 3 of high dose (350 mol Fe/300 g body weight) groups. The pathologic specimens were obtained in the infected synovium and soft tissue abscess and stained with hematoxylin-eosin. Prussian blue stain and CD68 stain were performed to detect the presence of iron particle and macrophage. We calculated the relative signal to noise ratio (SNR) change of infected synovium and soft tissue abscess wall on the precontrast- and SPIO-enhanced T2WI and compared between the relative SNR change and the total number of iron-loaded cells. Also we compared between the relative SNR change and the number of macrophages, or the number of fibroblasts, or the total number of iron-loaded cells in the soft tissue abscess wall. We analyzed a kind of iron-loaded cells and the uptake of iron particles in the macrophage or fibroblast according to the dose of SPIO.
Results: The SNR value after SPIO administration was decreased in proportion to the increase of the total number of iron-loaded cells in the infected synovium and soft tissue abscess wall (p < 0.05). In the soft tissue abscess wall the SNR value after SPIO administration was decreased in proportion to the increase of the number of macrophages, the number of fibroblasts, or the total number of iron-loaded cells (p < 0.05). The intracellular uptake of iron particles was in the fibroblast as well as in the macrophage and their uptake in the fibroblast was more than that in the macrophage (p < 0.05). There was no statistically significant difference in the uptake of iron particles in the macrophage or fibroblast according to the dose of SPIO (p > 0.05).
Conclusion: The intracellular uptake of SPIO and the change of SNR values were correlated in the infected synovium and soft tissue abscess wall. SPIO-enhanced MRI can be useful in the evaluation of the infectious disease of the joint or soft tissue, and is influenced by the uptake of iron particles in the fibroblast as wall as in the macrophage.
E242. Are Subscapularis Tendon Tears Associated With a Narrowed Subcoracoid Space
O'Dowd M.; LaFrance A.; Forster B.; Radiology, University of British Columbia, Vancouver, BC, Canada.
Address correspondence to M. O'Dowd (marianaodowd{at}yahoo.com)
Objective: To assess the importance of a reduced subcoracoid space dimension in patients with subscapularis tears.
Materials and Methods: Two observers independently obtained linear measurements from axial T1 and gradient echo MR images obtained at 1.5T in a control group of 15 patients without clinical symptoms of impingement and in 10 patients with surgically proven subscapularis tendon tears. The measurements obtained included the subcoracoid space, lateral humeral offset and joint line of the glenoid. Multivariate analysis of covariance adjusting for age and gender was performed.
Results: Patients with subscapularis tendon tears had statistically significant narrowing of the joint line of the glenoid (p < 0.05) and narrowing of the subcoracoid space (p < 0.05) when compared to controls. No significant difference in lateral humeral offset was seen between patients and controls (p = 0.24).
Conclusion: In our small study patients with subscapularis tendon tears had a narrowed subcoracoid space and decreased glenoid joint line dimension. These findings may have surgical relevance in patients presenting with rotator cuff tears, in that current surgical decompression techniques address the subacromion but not the subcoracoid space.
E243. A Challenging Interactive Review of Shoulder Anatomy, Physiology and Pathology with MRI and MR Arthrograms (MRA)
Robbin M.1; Zell S.I.2; Oneto J.2; Jose J.; Malajikian K.1; Bugnone A.1; 1. Department of Radiology, Case Western Reserve University, Cleveland, OH; 2. Department of Radiology, Mount Sinai Medical Center, Miami Beach, FL.
Address correspondence to M. Robbin (robbin{at}uhrad.com)
Background: Radiographic imaging of the shoulder is an essential component of the evaluation of patients with shoulder pain and trauma. Accurate radiographic evaluation of the shoulder requires an intimate knowledge of the anatomy, the relationship between stabilizing and destabilizing forces, and the imaging techniques most appropriate for evaluating various shoulder pathologies. Rotator cuff dysfunction is typically a continuum of pathology, with tendonitis and bursitis at one extreme, and partial to complete tear of one or more of the tendons at the other end of this spectrum. Non-rotator cuff pathology includes gleno-humeral instability and dislocation, as well as labral tears and pathology of the biceps tendon. In addition to history and physical exam, diagnosis of shoulder pathology is often made or confirmed with imaging studies, of which MRI plays a major role. MR arthrogram has become the most accurate method of depicting intra-articular anatomy and pathology. Evaluation of the undersurface of the rotator cuff and capsuloligamentous structures are permitted with this technique. It offers excellent detection and assessment of glenoid labral tears, small loose bodies, and cartilage flaps. MR arthrogram is considered the most useful tool for the evaluation of rotator cuff and non-rotator cuff pathology.
Key Issues: This exhibit will provide a comprehensive review, in an interactive format, of the shoulder anatomy, physiology, and mechanisms of injury. A discussion of reviewed cases with radiographic imaging, MRI and MRA correlation of rotator cuff and non-rotator cuff pathology will be presented.
Format: 400 MRI and MRA cases of the shoulder were reviewed and classified into three broad categories. Exams with normal findings, and abnormal examinations which were classified into categories of rotator-cuff pathology, and non-rotator cuff pathology. Findings were further analyzed and images were uploaded into an interactive exhibit to display the normal anatomy and physiology of the shoulder joint, as well as rotator cuff and non-rotator cuff pathology. Cases will be presented in a quiz format with explanations of the imaging findings and pathology.
Teaching Points: 1. To review and illustrate the anatomy and physiology of the shoulder joint with correlation to common pathology. 2. To discuss and illustrate the MRI/MRA appearance of rotator cuff and non-rotator cuff joint disease.
E244. Developmental Hip Dysplasia - Beyond the Clinical Diagnosis
Tivorsak T.L.; Patel K.; Carney K.; Klionsky N.B.; Tebor G.B.; Monu J.U.; Departments of Imaging Sciences and Orthopedics, University of Rochester School of Medicine and Dentistry, Rochester, NY.
Address correspondence to T.L. Tivorsak (tanya_tivorsak{at}urmc.rochester.edu)
Background: Developmental hip dysplasia (DDH), previously known as congenital dislocation of the hip, is a condition that is believed to be triggered by in-utero events but only begins to manifest after birth. The true incidence is uncertain since many cases go undiagnosed; moreover, the spectrum spans a dislocate-able unstable hip to a persistently dislocated hip. The clinical diagnosis is preferably in the perinatal period using the Ortolani and Barlow maneuvers. This exhibit highlights the role of imaging in the diagnosis and the management of this condition.
Key Issues: Plain radiographs, ultrasonography, CT and MRI are currently the preferred imaging tools to diagnose and follow patients with DDH. Radiographic diagnosis may be difficult prior to acetabular ossification. The differential diagnosis includes joint infections, neuromuscular disease, congenital coxa vara, Legge-Calve-Perthes disease and conditions of abnormal joint laxity like Downs, Ehlers-Danlos and the so called Larsen's syndromes. Management options vary between conservative (placement in brace, splint or cast) and operative measures (various osteotomies - Salter, Chiari and Pemberton procedures). Complications following management include AVN, massive chondrolysis and premature arthritis. Diagnosis of and management of CDH should be instituted in the neonatal period to achieve satisfactory treatment results. Management tends to be prolonged and the options vary with severity of the condition and how early the diagnosis is made.
Format: The presentation will be in a didactic format. Images will be used to describe the radiographic presentation and explain the basis of clinical diagnosis and management options.
Teaching Points: 1. The spectrum of developmental hip dysplasia. 2. The radiographic criteria for diagnosis. 3. Differentiate between DDH and other similar conditions. 4. What the surgeon needs to know from the images. 5. Current management options
E245. Muscular Dystrophies: What the Radiologist Should Know
Timberlake C.; Bang C.; Bakman M.; Seo G.; Monu J.U.; Department of Imaging Sciences, University of Rochester School of Medicine and Dentistry, Rochester, NY.
Address correspondence to C. Timberlake (carmen_timberlake{at}urmc.rochester.edu)
Background: Muscular dystrophies represent a spectrum of inherited myopathies affecting skeletal muscle, of which Duchenne muscular dystrophy is the most common. While the muscular dystrophies are clinical and pathologic diagnoses, they have imaging features that the radiologist should be familiar with.
Key Issues: MRI because of its exquisite soft tissue resolution is an tool for visual muscle assessment. Plain radiographs may demonstrate secondary effects of the disease such as limb deformities, spine deformities, and contractures. MRI and plain radiographs will be used to illustrate the patho-physiology and demonstrate the extent of disease.
Format: Our review of muscular dystrophies will be presented in a didactic poster format.
Teaching Points: 1. Review of spectrum of muscular dystrophies. 2. Review patterns of inheritance, pathophysiology of disease, clinical manifestations and sequelae of treatment. 3. Review radiologic findings in muscular dystrophies, with emphasis on Duchenne muscular dystrophy
E246. Musculoskeletal Manifestations of Hematological Diseases
Mazzie J.P.1; Ghelman B.2; Luchs J.S.2; Math K.R.4; Sadler M.1; Siegal S.5; Javors B.1; Katz D.S.2; 1. Department of Radiology, Saint Vincent's Catholic Medical Center, New York, NY; 2. Department of Radiology, Winthrop University Hospital, Mineola, NY; 3. Department of Radiology, Hospital of Special Surgery, New York, NY; 4. Department of Radiology, Beth Israel, New York, NY; 5. Department of Radiology, Holy Name Hospital, Teaneck, NJ.
Address correspondence to J.P. Mazzie (emperor07{at}hotmail.com)
Background: Hematological diseases can manifest in many different ways radiographically. One such way is via the musculoskeletal system. The purpose of this poster is to present a spectrum of cases that we have encountered in which hematological disorders affect the musculoskeletal system. The use of conventional radiographs will be emphasized with appropriate CT or MRI supplementation. Some of the diseases that will be presented include mastocytosis, amyloid, hemochromatosis, lymphoma and leukemic infiltration of bone, sickle cell anemia, hemophilia and myelofibrosis. The radiologic and clinical literature of these entities will also be reviewed.
Format: Interactive PowerPoint presentation.
Teaching Points: 1. Better appreciate the various musculoskeletal presentations of hematological diseases. 2. Able to provide a differential diagnosis for hematological diseases solely based on musculoskeletal findings.
E247. A Compartmental Approach to the Radiographic Evaluation of Soft Tissue Calcifications
Banks K.P.1; Bui-Mansfield L.T.1,2,4; Chew F.S.3; Collinson F.2; 1. Department of Radiology, Brooke Army Medical Center, San Antonio, TX; 2. Department of Radiology, Wake Forest University, Winston-Salem, NC; 3. Department of Radiology, University of Washington, Seattle, WA; 4. Department of Radiology, Uniformed Services University of Health Sciences, Bethesda, MD.
Address correspondence to K.P. Banks (Kevin.Banks{at}cen.amedd.army.mil)
Background: Despite increased use of cross-sectional imaging, radiography remains vital in evaluating disease of the spine and extremities. Therefore, it is essential that the practicing radiologist maximizes the diagnostic value of radiography. While much emphasis has been placed on the radiographic interpretation of osseous lesions, similar diagnostic yield can be obtained about calcified soft tissue lesions.
Key Issues: Analysis of the distribution and morphology of soft tissue calcifications, combined with knowledge of entities that occur at various anatomical sites, provides significant interpretive value. In the extremities, the soft tissues are subdivided into subcutaneous, neurovascular, fascial, muscular, and peri-articular compartments. In the spine, the compartments are the anterior and posterior longitudinal ligaments, intervertebral disk, interspinous and supraspinous ligaments, and paravertebral soft tissues. This anatomic approach allows for practical differentiation of soft tissue calcifications.
Format: The educational exhibit is in a Microsoft PowerPoint presentation format. The exhibit reviews the anatomy of the different compartments of the appendicular and axial skeleton. The exhibit presents different causes of soft tissue calcifications in the different compartments of the appendicular and axial skeleton.
Teaching Points: 1. Identify the anatomical compartments of the axial and appendicular skeleton. 2. List the common calcified or ossified lesions, which occur in the various compartments and their clinical context. 3. Provide a succinct differential diagnosis or definitive diagnosis when soft tissue calcifications are seen on radiography.
E248. Bone Manifestations of Drug Therapy
Chang P.C.; Motamedi K.; Seeger L.L.; Gold R.H.; Department of Radiology, David Geffen School of Medicine-UCLA Medical Center, Los Angeles, CA.
Address correspondence to P.C. Chang (pchang{at}mednet.ucla.edu)
Background: Skeletal disorders that arise from drug therapy are important to recognize since they may produce significant morbidity and some may be reversible. Radiologists play a central role in identifying and diagnosing the bony changes. Drug-induced skeletal abnormalities range from defective maturation, arthropathy, osteopenia and osteonecrosis to osteosclerosis and heterotopic ossification. Congenital dysplasias involving bone may result from drug therapy during pregnancy. With more medications being marketed now than ever before, drug-induced bony abnormalities are likely to increase.
Key Issues: Drug-induced disorders of bone can be divided into those that primarily reflect bone loss and those that primarily reflect bone increase. We will review our own cases as well as some in the published literature in order to show the spectrum of imaging findings. Examples will include drug-induced bone loss, such as that caused by corticosteroid, heparin, or bisphosphonate therapy, and drug-induced bone increase, such as that resulting from retinoid or fluoride therapy. Cases of congenitalskeletal dysplasia related to thalidomide or aminopterin therapy during pregnancy will be presented. The pathophysiologic basis for the bone findings will be explored.
Format: A pictorial review of skeletal manifestations will be presented in a didactic format, using radiographic imaging supplemented, where appropriate, by CT and MR imaging.
Teaching Points: The increasing use of pharmaceuticals makes it incumbent upon the radiologist to be able to recognize iatrogenic skeletal disease. Understanding the pathophysiologic basis for the abnormalities will assist the radiologist in identifying the pertinent findings. Physician awareness of the risks of various drugs will stimulate the monitoring of the skeletal system for their adverse effects, allowing for timely intervention whenever possible.
E249. Osteonecrosis of the Femoral head: Initial Experience Using Dynamic Gadopentate Dimeglumine-enhanced MR Imaging
Chan W.P.1; Huang G.S.2; Liu Y.J.3; Chang Y.C.4; Jiang C.C.5; 1. Department of Radiology, Taipei Medical University Wan-Fang Hospital, Taipei, Taiwan; 2. Department of Radiology, Tri-service General Hospital, National Defense Medical Center, Taipei, Taiwan; 3. Department of Automatic Control Engineering, Feng Chia University, Tainan, Taiwan; 4. Department of Mathematics, Tamkang University, Taipei County, Taiwan; 5. Department of Orthopedic Surgery, National Taiwan University and Hospital, Taipei, Taiwan.
Address correspondence to W.P. Chan (wp.chan{at}msa.hinet.net)
Objective: To assess intramedullary hemodynamic changes relating to severity of osteonecrosis of the femoral head (ONFH) using dynamic contrast-enhanced MR imaging (DCE-MRI).
Materials and Methods: Twelve patients (14 symptomatic ONFH) who underwent DCE-MRI and had subsequent core decompression and biopsy of the femoral head were reviewed. DCE-MRI was obtained with use of T1-weighted (300/25) sequence on a coronal plane at 16-s acquisition time for each image for 5 minutes after bolus injection of 0.2 ml/kg of gadopentate dimeglumine. Another 13 normal volunteers (26 asymptomatic hips) were recruited as control. Severity of ONFH was graded from 0 (elevated intramedullary pressure only) to II (collapse) by MRI findings.
Results: In the femoral head, the peak (and rate) percentage of enhancement was 4.17±1.85 (rate, 3.49±1.86) for control hips, 3.74±3.05 (3.57±0.15) for stage 0 (n = 3 hips), 19.35±10.33 (12.10±6.87) for stage I (n = 5), and 46.56±25.40 (17.72±4.45) for stage II (n = 6) ONFH (Kruskal-Wallis test, p < 0.001). In the femoral neck, the peak (and rate) was 7.40±6.26 (7.79±8.28) for control hips, 6.95±6.45 (13.15±13.41) for stage 0, 12.62±4.81 (13.22±11.36) for stage I, and 73.67±11.91 (27.72±7.14) for stage II ONFH (p < 0.001). The peak (and rate) of the intertrochanteric areas was 7.23±4.56 (6.96±5.39) for control hips, 9.43±4.69 (12.01±7.74) for stage 0, 20.24±16.02 (11.82±5.76) for stage I, 41.81±21.31 (20.80±7.37) for stage II ONFH (p < 0.001). Control hips versus stage I and II ONFH were significant in various femoral sites (Mann-Whitney test, p < 0.001).
Conclusion: Increased intramedullary perfusion in various femoral sites was noted with progression of severity of ONFH as assessed by DCE-MRI.
E250. Dynamic Gadolinium-enhanced MR Imaging in Assessment of Osteonecrosis of the Femoral Head: Chicken Model
Chan W.P.1; Kuo T.F.2; Cheng C.J.3; Lin M.F.1; Jiang C.C.4; 1. Department of Radiology, Taipei Medical University Wan-Fang Hospital, Taipei, Taiwan; 2. Agriculture College, National Taiwan University, Taipei, Taiwan; 3. Department of Pathology, Taipei Medical University School of Medicine, Taipei, Taiwan; 4. Department of Orthopedic Surgery, National Taiwan University and Hospital, Taipei, Taiwan.
Address correspondence to W.P. Chan (wp.chan{at}msa.hinet.net)
Objective: To assess hemodynamic changes of various stages of osteonecrosis of the femoral head with use of dynamic contrast-enhanced MRI (DCE-MRI) in a chicken model.
Materials and Methods: Twenty-nine white Leghorn female chickens were recruited as experimental group. Each animal received methylprednisolone (3 mg/kg, IM) every other day. All chickens received DCE-MRI before steroid injection (baseline) and before scarification at week 0, 12, 19, 40, respectively, after steroid injection. DCE-MRI was performed by using T1-weighted imaging at 12-sec intervals for 7 minutes synchronous after intravenous bolus injection of gadopentetate dimeglumine. Histology was staged from I to III. Another 20 chickens without steroid injection were recruited as control group.
Results: In the femoral head, the peak percentage of enhancement in stage I (n = 4 chickens), II (n = 13) and III (n = 12) diseases was 84.6±14.3, 103.5±44.8, 84.4±27.8, respectively (p =0.47). The peak of the femoral neck was 92.3±13.6 for stage I, 91.7±44.8 (II), 84.21±3.3 (III), respectively (p = 0.56). The peak of the intertrochanteric areas was 101.8±13.7 (stage I), 116.2±48.5 (II), 80.6±23.9 (III), respectively (p = 0.03). Pooling of RBC was remarkable in the intertrochanteric areas on histology. In control animals, the peak in three various femoral sites of three age groups (week 25, 30, 35) revealed no statistical significant (p > 0.05).
Conclusion: Our results supported Ficat's hypothesis that intramedullary stasis in the intertrochanteric areas can be a common pathway to initial the ischemic process of osteonecrosis of the femoral head, and DCE-MRI is feasible in detection of such hemodynamic changes in a chicken model.
E251. Advanced Imaging Features of Gout
Russell J.M.1; Bancroft L.W.1; Kransdorf M.J.1,2; Peterson J.J.1; Berquist T.H.1; Murphey M.D.2,3,4; 1. Diagnostic Radiology, Mayo Clinic, Jacksonville, Jacksonville, FL; 2. Department of Radiologic Pathology, Armed Forces Institute of Pathology, Washington, DC; 3. Department of Radiology and Nuclear Medicine, Uniformed Services University of Health Sciences, Bethesda, MD; 4. Department of Radiology, University of Maryland School of Medicine, Baltimore, MD.
Address correspondence to J.M. Russell (russell.james{at}mayo.edu)
Objective: The purpose of this study is to define the imaging characteristics of gout on magnetic resonance imaging (MRI), computed tomography (CT) and 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) imaging.
Materials and Methods: Retrospective review was made of the MRI (n = 17), CT (n = 6) and FDG-PET (n = 2) studies in 14 patients with a documented diagnosis of gout. Twenty-one joints and two bursae were affected. There were 9 males and 5 females, with a mean age of 53 years (range = 24-84 years). Imaging studies were reviewed for the presence/location of tophi and osseous MR signal changes. Tophi were evaluated for size, signal characteristics and enhancement pattern with MRI, density on CT, and degree of uptake on PET imaging.
Results: Gouty involvement included the MTP joint (n = 4), midfoot (n = 4), knee (n = 4), lumbar spine (n = 2), thoracic spine (n = 1), SI joint (n = 2), hindfoot (n = 1), wrist (n = 1), IP joint of the finger (n = 1) and MCP joint (n = 1). Bursitis was identified in the prepatellar (n = 1) and olecranon (n = 1) bursae. MRI examinations demonstrated tophi in all cases. Longest dimension of individual or conglomeration of tophi averaged 4 cm (range = 0.9-16 cm). All but 4 tophi demonstrated signal intensity isointense to skeletal muscle on T1-weighted images: one was slightly hyperintense to muscle and three had mixed isointense/hypointense signal. All cases demonstrated intermediate signal within at least portions of the tophi on fluid-sensitive sequences; hypointense signal was also common, but varied according to the specific sequences obtained. All tophi demonstrated enhancement on gadolinium-enhanced MRIs; most were intense, peripheral and heterogeneous. All tophi imaged with CT were denser than skeletal muscle; two demonstrated distinct foci of calcification. The first patient undergoing FDG-PET imaging had moderate uptake in the lumbar spine, midfoot and MTP joints. The second patient had marked uptake in the thoracic and lumbar spine, and mild uptake in the SI joints.
Conclusion: Although gout most commonly involved the feet and knees, a multitude of joints were affected. Gouty tophi were isolated or multifocal, and ranged greatly in size. MRI and CT demonstrated characteristic imaging findings. Most tophi were isointense to muscle on T1-weighted sequences, isointense/hypointense on fluid-sensitive sequences, and enhanced intensely. All tophi were denser than skeletal muscle, with occasional calcification on CT. Uptake by gouty tophi on FDG-PET imaging was marked, moderate or mild.
E252. The Reverse Total Shoulder Prosthesis: Imaging Features and Complications
Fayad L.M.1; Keyurapan E.2; Fishman E.K.1; Tasaki A.2; McFarland E.2; 1. Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD; 2. Department of Orthopaedic Surgery, Johns Hopkins Medical Institutions, Baltimore, MD.
Address correspondence to L.M. Fayad (lfayad1{at}jhmi.edu)
Background: A new generation of total shoulder prosthesis, known as the "reverse shoulder prosthesis" (RSP), has been introduced into the United States as of April, 2004. The RSP has a novel design which reverses the usual ball and socket arrangement of the shoulder, placing a ball in the glenoid fossa and a flat surface in the position of the humeral head. In patients with advanced rotator cuff arthropathy, failed hemiarthroplasty with rotator cuff disease or superior subluxation of the humerus dueto rotator cuff disease, the RSP is advantageous as it resists glenohumeral subluxation and offers improved function. This exhibit will review the components of this prosthesis and its normal imaging appearance. In addition, the radiographic manifestations of the complications associated with the RSP will be presented. Some complications reported with the RSP are similar to shoulder arthroplasty performed upon patients with complex reconstructions of the shoulder, such as hematoma formation, infection and nerve damage. However, common complications include dislocation of the components, notching of the scapula by the humeral component, fracture of the surgical screws and acromial stress fractures.
Key Issues: This exhibit will discuss the normal components and imaging appearance of the Reverse Shoulder Prosthesis. The common complications which occur with the prosthesis will be reviewed along with the associated imaging findings.
Format: Format: Didactic Organizational Structure: By Pathology/Complications.
Teaching Points: 1-To describe the normal imaging appearance of the reverse shoulder prosthesis. 2-To review the radiographic manifestations of the common complications associated with the reverse shoulder prosthesis. 3-To raise the awareness of this new device among radiologists.
E253. Total Shoulder Arthroplasty: Normal and Abnormal Ultrasound Findings
Brandon C.J.; Xerogeanes J.; Radiology, Emory University, Atlanta, GA.
Background: MRI has become the preferred imaging method for the shoulder but metallic artifact limits evaluation of the patient with a total shoulder prosthesis. While CT readily detects loosening of the glenoid component, a common post operative complication, soft tissue evaluation is similarly limited. When clinical suspicion suggests soft tissue damage, familiarity with the ultrasound appearance of normal and abnormal post-operative findings can aid in diagnosis and direct additional surgical planning.
Key Issues: The normal ultrasound appearances of the rotator cuff and anterior shoulder structures are altered by the anterior surgical approach for total shoulder arthroplasty. First comparison will be made between normal non-operative shoulder and uncomplicated post-operative ultrasound examinations. These cases will demonstrate some of the subtle changes in the relationship between the rotator cuff tendons and the prosthetic humeral head. The subscapularis muscle and tendon are especially prone to undergo post-operative change and the relationship of the muscle to the coracoid process and the tendon insertion on the lesser tuberosity will be reviewed. Then cases demonstrating such postoperative complications as full thickness rotator cuff tears, extensive synovial reaction, subscapularis rupture and avulsion will be given. Surgical correlation will be provided and when available, intra-operative photography shown. Instructions on how to scan the post-operative shoulder will be given with photographs of transducer placement on the post-operative patient.
Format: Didactic format will be used with comparison among normal non-operative, uncomplicated post-operative, and problematic post-operative prosthetic shoulders. Correlation will be made with surgical follow-up and intra-operative photography when available.
Teaching Points: To recognize the expected alterations associated with total shoulder arthroplasty and to diagnosis some of the common soft tissue complications seen with ultrasound.
E254. Radiology of Hip Replacement Hardware: Review and Self-Assessment
Roberts C.C.1; Chew F.S.2; 1. Department of Radiology, Mayo Clinic Scottsdale, Scottsdale, AZ; 2. Department of Radiology, University of Washington, Seattle, WA.
Address correspondence to C.C. Roberts (roberts.catherine{at}mayo.edu)
Background: Over the past few decades, hip replacement has been one of the most common orthopedic surgical procedures being performed in the United States. With advancing technology, a myriad of materials and hardware is now in use, each with a specific purpose and indication.
Key Issues: Recognizing the normal and abnormal appearances of these prostheses and their components is critical to accurate radiologic interpretation. Standard terminology ensures clear communication with the orthopedic surgeons caring for these patients. Complications, both common and uncommon, occur in predictable areas.
Format: This computer-based educational exhibit reviews the radiology of hip replacement hardware so that the practicing radiologist can recognize and accurately describe the appearance of these devices. Participants may take an interactive self-assessment quiz.
Teaching Points: The objectives of this educational activity are for the participant to: 1. Learn the history of hip replacement hardware. 2. Recognize the different types of hip replacements and materials used. 3. Understand the indications for use of different hip prostheses. 4. Know where to look for common complications. 5. Be able to use standard terms in describing hip prostheses.
E255. Radiology of Knee Replacement Hardware
Chew F.S.1; Roberts C.C.2; 1. Department of Radiology, University of Washington, Seattle, WA; 2. Department of Radiology, Mayo Clinic Scottsdale, Scottsdale, AZ.
Address correspondence to F.S. Chew (fchew{at}u.washington.edu)
Background: Over the past few decades, knee replacement has been the most common elective orthopedic surgical procedure being performed in the United States. With advancing technology, a myriad of materials and hardware is now in use, each with a specific purpose and indication.
Key Issues: Recognizing the normal and abnormal appearances of these prostheses and their components is critical to accurate radiologic interpretation. Standard terminology ensures clear communication with the orthopedic surgeons caring for these patients. Complications, both common and uncommon, occur in predictable areas.
Format: This computer-based educational exhibit reviews the radiology of knee replacement hardware so that the practicing radiologist can recognize and accurately describe the appearance of these devices. Participants may take an interactive self-assessment quiz.
Teaching Points: The objectives of this educational activity are for the participant to: 1. Learn the history of knee replacement hardware. 2. Recognize the different types of knee replacements and materials used. 3. Understand the indications for use of different knee prostheses. 4. Know where to look for common complications. 5. Be able to use standard terms in describing knee prostheses.
E256. Joint Replacement Complications
Kayes A.V.; Bancroft L.W.; Beaman F.D.; Peterson J.J.; Berquist T.H.; Kransdorf M.J; 1. Radiology, Mayo Clinic Jacksonville, Jacksonville, FL.
Address correspondence to A.V. Kayes (kayes.andrew{at}mayo.edu)
Background: Joint replacements have steadily increased in number over the past several decades, with more than 800,000 cases performed annually worldwide. The understanding and treatment of joint replacement complications have yielded improvements in arthroplasty components, surgical techniques and antibiotic therapy. Despite these advances, joint replacement complications are not uncommon. For example, the literature has reported periprosthetic fracture rates after total hip arthroplasties of 1-6% and hip dislocation rates of 7% at twenty-five years. Imaging continues to play a key role in the characterization and prompt diagnosis of a variety of joint replacement complications, thereby reducing further patient morbidity and mortality.
Key Issues: 1. Loosening; 2. Particle disease (component wear, osteolysis, metallosis, silicone synovitis); 3 Malposition (component rotation, migration, dislocation); 4. Dissociation (acetabular liner, tibial tray, elbow screw); 5. Component fracture (metallic, polyethylene, silicone); 6. Infection (loosening, sinus tract, osteolysis, soft tissue abscess, requiring hardware removal/arthrodesis); 7. Unintended intraoperative complication (saw injury, fracture); 8. Soft tissue pathology (joint instability/dislocation, heterotopic ossification); 9. Impingement/delayed fracture.
Format: We will employ an interrogative question-and-answer format, and organize several case presentations by pathology. Each case presentation will provide a brief history and relevant images (radiographs, CT, nuclear medicine and MRI). Imaging findings, differential diagnosis and correct diagnosis will be discussed. Subsequently, the presentation will speak to each joint replacement complication and give pertinent references.
Teaching Points: Following completion of this educational exhibit, participants will be able to define complications of joint replacement and recognize their associated imaging characteristics.
E257. Lumbar Disc Arthroplasty: Indications, Contraindictions, and Radiological Assessment
Yoon W.W.1; Jayakumar J.2; Natali C.2; 1. Trauma and Orthopaedics, The Royal London Hospital, London, United Kingdom; 2. Radiology, St. Thomas' Hospital, London, United Kingdom.
Address correspondence to W.W. Yoon (wwyoon{at}mac.com)
Background: Degenerative disc disease is the leading cause of pain and disability in adults in North America. The lumbar artificial disc is an alternative to arthrodesis. It is different from fusion in that its aim is to restore the basic motion of the intervertebral segment and thereby protecting adjacent levels against increased stress concentration.
Key Issues: The issues addressed in this exhibit encompass the indications and contraindications to this surgery as well as the fundamental radiographic work up used in our practice. Emphasis will be placed on the anatomy of the procedure highlighting the importance of radiographic pre-operative planning, including Plain radiographs, CT and MRI scans.
Format: The format will be didactic starting with the indications and pathology that may require disc replacement. We will then lead on to the anatomy section with radiographs and anatomical views to correlate the two. A brief overview of the operative procedure will then follow and post-operative radiographs will be shown.
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