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ABSTRACT |
Monday, May 1, 10:00 AM–12:00 PM
Abstracts 032–043
Moderators: Vikram Dogra, MD and Hani H. Abujudeh, MD
10:00 AM
032. A Survey of Digital Teaching Methods in Anatomy Courses in US and Canadian Medical Schools
Ganske I.M.*; Su T.J.; Loukas M.; Shaffer K.; Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
Address correspondence to I.M. Ganske (ingrid_ganske{at}hms.harvard.edu)
Objective: To determine current and planned future use of radiological and digital teaching methods in anatomy courses.
Materials and Methods: A survey was sent to AAMC-listed medical schools. The survey included questions relating to the design, duration, and topics of the anatomy course, including current and planned future use of radiology and digital histologic slides.
Results: There were 60 responses (
50%). The majority of the
schools (32) offer anatomy as a semester course. Other schools have shorter
intensive courses, courses distributed throughout the year, or other designs.
The majority of course directors are anatomists and cell biologists, and only
one is a radiologist. Currently the majority of time is spent on dissection
(51%) and lectures (27%). Radiologic anatomy averages 4.5% of course time.
Most schools plan to devote fewer hours to anatomy teaching in the next 5
years; time spent on lectures, dissections, and prosections will decrease,
while the use of digital teaching methods will increase. Thirty-one schools
report teaching histology in the anatomy course, and on average spend 61% of
the time using slides, 17% using the web, and 17% using digital slides. In the
next 5 years, they predict cutting the use of microscope slides in half and
doubling their use of digital slides. Currently 21 schools use some digital
slides, 3 schools use solely web-based and/or digital slides, and 3 schools
plan to convert to digital histology within the next 5 years. Multiple choice,
gross lab practical, and radiology exam questions are used by most responders.
Most schools use a pass-fail (19) or pass-fail-honors (17) grading system.
Conclusion: Traditional teaching methods currently dominate anatomy education with dissections and lectures comprising the majority of class time, and a small proportion of time devoted to radiologic anatomy. Most schools expect to decrease the total hours allotted to teaching anatomy over the next 5 years, without changing the amount of time devoted to radiology. Although imaging is used by most schools (49) in anatomy exams, it comprises only a small percentage of allotted current and planned future teaching time (4.5%). In view of the importance of radiologic anatomy to patient care, imaging should probably play a larger role in teaching anatomy in the future. The trend toward digital teaching of histology suggests computer infrastructure for expanded use of digital images for teaching may already be in place or planned for the future.
033. Can Radiation Exposure Associated with Abdominal and/or Pelvic CT be Minimized with Better Practice? Initial Results Namasivayam S.*; Kalra M.K.; Mittal P.; Hudgins P.; Tigges S.; Small W.C.; Radiology, Emory University Hospital, Altanta, GA.
Objective: 1) To determine the additional length of localizer radiograph as well as number of "extra" images acquired beyond the intended anatomic area of interest with abdominal and/or pelvic CT 2) To determine the additional radiation exposure and diagnostic usefulness of these extra images.
Materials and Methods: IRB approval was obtained. Superior and inferior levels at routine abdominal and/or pelvic CT were defined as the dome of the diaphragm and the inferior margin of the pubic symphysis, respectively. In this ongoing study of 200 patients, fifty consecutive abdomen-pelvic CT (mean age, 49 years; age range, 21–86 years; M:F, 38:12) have been reviewed so far to determine the additional length of localizer radiographs, and "extra" axial images acquired beyond defined levels. Two radiologists independently reviewed all localizer radiographs and "extra" images for findings. Localizer radiographs were acquired with 120 kVp and 80 mAs. Abdominal-pelvic CT was performed with 120 kVp, and automatic exposure control using 12 noise index, and 120–440 mA, and a 0.5 second gantry rotation time. CT parameters recorded for each extra image included tube current, and gantry rotation time. Mean tube current-time products were calculated for extra images. Statistical analysis was performed with student t test and correlation analysis.
Results: Localizer radiographs were extended above diaphragm (mean length, 72.6 mm), and below symphysis (mean length 59.4 mm) pubis in 48/50 (96%), and 36/50 (72%) examinations, respectively. Extra images were acquired above the dome of the diaphragm in 47/50 (94%), and below the pubic symphysis in 45/50 (90%) examinations, respectively. A total of 562 extra images were acquired in 50 examinations (mean, 11 images per examination). One additional finding (subsegmental atelectasis) was observed on extended localizer radiograph, and five additional findings were detected on extra images. The mean tube current-time product was 87.3 and 153.2 mAs for extra images acquired above the diaphragm and below the pubic symphysis, respectively.
Conclusion: In most cases, acquisition of additional length of localizer radiographs and extra images acquired at abdominal and/or pelvic CT does not contribute additional diagnostic information. Appropriate selection of region for localizer radiographs, as well as axial CT image acquisition can result in substantial radiation dose reduction.
034. The Costs of Pre-Screening with Coronary CTA
Frangos A.J.*; Halpern E.J.; Levin D.C.; Zhang S.; Radiology, Thomas Jefferson University, Philadelphia, PA.
Address correspondence to A.J. Frangos (andrea.frangos{at}jefferson.edu)
Objective: To determine the CTA reimbursement at which CTA of the coronary arteries would be cost-effective as a pre-screening test prior to non-emergent cardiac catheterization.
Materials and Methods: A cost-minimization analysis was performed. The frequency of normal cardiac catheterization in the non-emergent setting was estimated to be between 10–30% (Farrehi, et al, Am J Manag Care 2002; 8:643–648). For the purposes of this analysis, we assumed that the negative predictive value of normal coronary CTA was 100%, the specificity was 98% (Morgan-Hughes, et al, Heart 2005; 91:308–313), the side effects of the coronary CTA were negligible, and all patients that did not have a normal CTA were evaluated with cardiac catheterization. The cost of the cardiac catheterization procedure was determined from the 2005 Medicare Fee Schedule. We did not include the cost of hospitalization associated with cardiac catheterization. We used a decision tree approach to cost analysis to determine the cost at which pre-screening with coronary CTA became the dominant diagnostic strategy.
Results: As the frequency of normal subjects referred for cardiac catheterization varies from 10–30%, pre-screening with coronary CTA is cost-effective as long as the cost is no more than 9.7–29.1% of the cost of a negative cardiac catheterization. In actual dollars, coronary CTA pre-screening becomes a dominant strategy when the cost is less than $270 at 10% and $810 at 30% negative cardiac catheterization rates.
Conclusion: The cost-effectiveness of coronary CTA as a pre-screening test prior to non-emergent cardiac catheterization is highly dependent on the frequency of negative cardiac catheterizations. If the cost of coronary CTA is less than 10% of the cost of cardiac catheterization, then pre-screening becomes the dominant strategy. When one considers the additional diagnostic information provided by coronary CTA, including the etiology for non-coronary chest pain and surgical anatomy that may be useful for pre-operative evaluation prior to bypass (ie, aortic anatomy and calcification), as well as the additional costs for hospitalization associated with cardiac catheterization, pre-screening of patients with coronary CTA prior to cardiac catheterization will be the dominant strategy even at a higher cost.
035. Patient Comprehension of Informed Consent for Spine Injection
Dharia C.; Bennett D.L.*; Ferguson K.J.; Okon A.E.; Radiology and Office of Consultation and Research in Medical Education, University of Iowa Carver College of Medicine, Iowa City, IA.
Address correspondence to D.L. Bennett (lee-bennett{at}uiowa.edu)
Objective: The purpose was to evaluate different methods for improving patient comprehension of informed consent for spinal injection procedures. The study was designed to compare 2 alternate methods of educating patients about the procedure, complications, and home care instructions with our current method of providing informed consent information. Historically, informed consent forms have been developed for the purpose of educating patients. However, informed consent forms can be very difficult to understand. Physicians may attempt to describe the details to the patient, yet this does not necessarily mean that the patient understands what they are being told.
Materials and Methods: This was a prospective, randomized, controlled study. 83 of 93 consecutive patients undergoing a spine injection agreed to participate and completed the study. The patients were randomly assigned to the control group (informed consent obtained in the customary manner at our institution with 12 key points of consent and home-care discussed conversationally); the teach-the-teacher group (patients had to repeat the 12 key points to the physician before informed consent was complete); and the diagram group (patients viewed a set of diagrams illustrating the 12 key points before signing the informed consent form). Any patient questions (regardless of group) were answered by the consenting physician. After the procedure, the patients finished a multiple choice survey to test comprehension of the procedure, anxiety during the procedure, and pain during the procedure. The collected data were analyzed using SAS®. P = 0.05 was considered significant.
Results: There was no statistically significant difference among the three groups in age, gender, education level, pain rating, and anxiety rating. The average score (out of 10) was 5.71 (control), 7.39 (teach-the-teacher), and 7.14 (diagram). The control group score was statistically significant from and lower than the other groups. Interestingly, there was a statistically significant (p = 0.05) negative correlation between age and score in the teach-the-teacher group, and a similar trend between age and score in the control group (p = 0.08). The scores of the subjects 70 and older support this, with averages of 5.14 (control), 6.28 (teach-the-teacher), and 7.44 (diagram).
Conclusion: In our study, the teach-the-teacher method achieved the best measurable comprehension in the young adult and middle-aged. The diagram method achieved the best measurable comprehension in the elderly.
036. Overlapping Scan Volumes of Multi-region CT: Radiation Exposure and Diagnostic Usefulness of "Duplicate" Images
Namasivayam S.*; Kalra M.K.; Mittal P.K., Hudgins P.A.; Tigges S.; Small W.C.; Radiology, Emory University Hospital, Atlanta, GA.
Objective: Combined chest-abdomen and neck-chest CT protocols are often acquired with overlapping helical acquisitions. The purpose of our was to determine additional radiation exposure and diagnostic usefulness of "duplicate" images resulting from overlapping scan volumes with combined chest-abdomen CT, and neck-chest CT protocols.
Materials and Methods: IRB approval was obtained. in an ongoing analysis of 200 patients, so far, image datasets of 25 consecutive combined chest-abdomen CT (mean age, 57 years; age range, 37-81 years; M:F, 39:11), and 21 combined neck-chest CT (mean age, 58 years; age range, 27-90 years; M:F, 13:8) studies have been reviewed to determine the number of "duplicate" axial images from overlapping scan volumes and assess clinically important findings in each set of "duplicate" images. Mean tube current-time products were calculated for "duplicate" images. Chest-abdomen CT was performed with 120 kVp, automatic exposure control (AEC) using 12 noise index, and 120-440 mA, and a 0.5 second gantry rotation time. Scanning parameter for neck-chest CT were 120 kVp, AEC with 10 noise index, and 100-440 mA, and a 0.5 second rotation time. Data was analyzed using parametric and nonparametric tests.
Results: Initial results indicate that several "duplicate" images are acquired from overlapping scan series of all chest-abdomen CT, and neck-chest CT studies assessed so far. A total of 1057 "duplicate" images were acquired in 46 examinations. On average, 25 "duplicate" images were acquired in each chest-abdomen CT and 20 in each neck-chest CT. "Duplicate" images in chest-abdomen CT revealed 32 additional findings. Only one clinically important lesion, hypervascular hepatic lesion, was seen in a chest CT images and not in abdominal dataset. For neck-chest CT protocol, all findings (n = 10) were detected on both neck and chest datasets. The mean tube current-time product was 162.5 and 208.7 mAs for duplicate images of chest-abdomen, and neck-chest CT, respectively.
Conclusion: Multi-region CT studies are associated with acquisition have "duplicate" overlap region images, which result in substantial radiation exposure. Most findings on these images are seen in either region dataset. Appropriate selection of scanning technique for a single helical acquisition of multi-region scanning can result in substantial radiation dose reduction, while maintaining the diagnostic accuracy.
037. The Principle of a Sensitive and Accurate De-convolution technique to Detect and Enhance Image Edge-profiles in CT, MR and DF
Chui S.L.2; Chui K.M.1*; Stanfield D.B.1; 1. Research and Development, Image Enhancement Technology, Uxbridge, United Kingdom; 2. Radiology, Alexandra Hospital, Redditch, United Kingdom.
Address correspondence to K.M. Chui (ming-chui{at}iet.org.uk)
Objective: Due to the size of the energy source and detector(s), Line Spread Functions (LSF) or blurred Edge Response Functions (ERF) in the Image Domain are obtained from a Delta Function or a Step Function of the Object Domain. The blurring in CT and MR images is 2.4 pixels across in average. A patented De-Convolution Technique uses a Running Filter to point-point the true edge position to sub-pixel accuracy. The original high resolution feature of the edge profile may be restored via an Algorithm to correct empirically for the `Penumbral Spread' under strict spatial bandwidth controls to avoid ambiguity.
Materials and Methods: A New York Cathan 500 was examined with single detector CT for calibrations. The De-Convolution and Back-Projection software was implemented in C++ and incorporated into the DicomObjects toolkit. The 1% low-contrast phantom rods and the high contrast Teflon sections were scanned and analyzed for the low-contrast and high contrast resolutions and distance and area/volume measurement calibrations. MTF at the high contrast was analyzed by the Judy P.F. Method (Med. Phys. Vol.3, No.4, Jul/Aug 1976, pp.233-236).
Results: Distance Measurements: Mean accuracy to 1/50th of a pixel (dr/r) at 1% low-contrast edge. Area/Volume: Mean accuracies to 1/30th and 1/10th of a pixel (dr in 2prdr/pr2) in area, and volume (Volume=Area*Slice-thickness) at high and 1% low-contrast edges respectively. MTF at high contrast edge improves from 5.83 lp/cm to 13.90 and 15.03 lp/cm at 10% normalized modulation level after 5x and 7x magnification and enhancement. Low Contrast Resolution: detected 0.3% low-contrast to 2mm rod at 300mA, 120kVp, 10mm slice. Random noise effect on the enhanced linear edge profile was reduced as indicated by da1 and da0 in Y = (a2±da2)X2+(a1±da1)X+(a0±da0) from 57.50% to 12.40% and 1.47% to 0.38% respectively by a Dynamic Filter.
Conclusion: The ERF blurring/Penumbral Spread cannot be overcome by current digital enhancement. This technique permits sensitive and accurate edge profile detection and enhancement. Potential applications are in radiological diagnosis, oncological responses, microsurgery, and radiotherapy treatment planning. Various field trial examples are illustrated separately.
038. Diagnostic Accuracy for Interpreting Ferumoxtran-10 Enhanced MRI: Does it Improve after Radiologist Training?
Jantsch M.K.1,2*; Saksena M.A.1; Braschi M.1,2; Boland G.W.1; Mahmood U.2; Harisinghani M.G.1,2; 1. Radiology, Massachusetts General Hospital, Boston, MA; 2. Radiology, Center for Molecular Imaging Research, Boston, MA.
Address correspondence to M.K. Jantsch (mjantsch{at}partners.org)
Objective: Ferumoxtran-10 enhanced MRI for nodal assessment requires some baseline experience for image interpretation. The purpose of this study was to assess the difference in radiologists reading performance before and immediately after undergoing training.
Materials and Methods: Retrospective analysis of 167 nodes was performed in 76 patients (M:F; 57:19), with surgically proven lymph nodes in various primary cancers (bladder [20], breast [10], endometrial [1], renal [2], pancreas [1], penile [4], prostate [30], rectal [1], testicular [5], ureteral [2]). All nodes were evaluated on T2 weighted fast spin echo (FSE) (TR/TE, 4500/24; FA 90°; FOV 24; slice 3mm; matrix, 256 x 256) and T2*-weighted gradient-echo (GRE) (TR/TE, 2100/24; FA 70°; FOV 26; slice 3mm; matrix, 160 x 256) MR imaging at 1.5T, before and 24-36 hours following IV administration of ferumoxtran-10 (2.6 mg Fe/Kg). Two board certified radiologists with no experience in reading ferumoxtran-10 enhanced MR images performed qualitative image evaluation. In session 1, readers reviewed pre and post contrast T2 and T2* weighted images using a 6-point scale to characterized lymph nodes. 15 days later both readers underwent training by a radiologist familiar with nodal enhancement patterns with efrumoxtran-10. They then reinterpreted the same image data set using a 6-point scale. Receiver operating characteristic analysis (ROC) was performed tocompare the readers' performance in detecting nodal metastases with and without training.
Results: Of the evaluated 167 lymph node groups 55 were benign and 112 malignant by histopathologic analysis. The ROC curve for the diagnostic accuracy pre training [reader 1:Az = 0.90 (95% CI 0.843-0.958); reader 2: Az = 0.894 (95% CI 0.84.8-0.94)] was statistically different (reader 1: p = 0.04; reader 2: p = 0.04) from the post training ROC curve [reader 1: Az = 0.95 (95% CI 0.90-0.98); reader 2: Az = 0.94 (95% CI 0.91-0.98)].
Conclusion: The diagnostic performance of radiologists with little experience in interpreting ferumoxtran-10 enhanced MRI for detecting nodal metastases can be improved with training prior to reading these studies.
039. Evaluation of CTA Technique using 64-Row Detector CT
Lucey B.C.*; Varghese J.C.; McGinnis P.; Soto J.A.; Department of Radiology, Division of Body Imaging, Boston University Medical Center, Boston, MA.
Address correspondence to B.C. Lucey (brian.lucey{at}bmc.org)
Objective: To show that a decreased volume of intravenous contrast may be used with 64 detector CT for performing CTA while maintaining adequate vessel opacification.
Materials and Methods: We reviewed all CTA examinations performed from 8/10/05 to 9/26/05 at our institution. All CTA was performed on a 64 row detector CT (GE, Milwaukee, USA). A total of 100 examinations were included. Males: females, 49:51, age range 17-89 years, mean age 54 years. Sixty mL of intravenous contrast (Ioversol 350 mg/mL) with a timing bolus was used in all cases. There were 73 CTPA, 15 aortic CTA, 3 renal CTA, 4 pelvis with lower extremity CTA, 4 lower extremity and one upper extremity CTA performed. Hounsfield units were measured at six locations for CTPA, 5 locations for renal CTA, 5 locations for pelvic or extremity CTA and 4 locations for aortic CTA and 3 locations for abdominal aortic CTA. Values > 200 HU were deemed excellent opacification. Values between 150 and 200 HU were deemed satisfactory. Values < 150 HU were deemed poor opacification.
Results: There were a total of 545 segments evaluated. Four segments could not be evaluated due to extensive clot occluding the vessels in these segments. 445 of 545 (82%) segments had excellent opacification. Of the remaining 98 (18%) segments, 58 (11%) had satisfactory opacification. A total of 40 (7%) segments had poor opacification. 28 (70%) of these poorly opacified segments occurred in 6 CTA studies. Four of these were CTPAs and two of these were lower extremity CTA examinations. These six studies were considered poor studies and the errors resulted from inadequate timing of the contrast bolus. In the case of the extremity CTAs, the scan was performed too soon and the scanner outran the contrast bolus resulting in poor opacification in the extremity vessels. In the case of the four CTPAs, the timing was also an issue with images being acquired too early.
Conclusion: Using smaller volumes (60mL) of intravenous contrast is feasible and produces excellent vessel opacification in a majority of cases. Care must be taken with timing of the contrast bolus to avoid out-running the contrast material as errors may occur with inadequate planning or technique.
040. A Quantitative Method to Determine Appropriate Percentage of Global Reimbursement for Radiology Professional Fee Contracts
Berlin J.W.1*; Rhoads R.1; Lexa F.J.2; Yaghmai V.3; Edelman R.R.1; 1. Department of Diagnostic Radiology, Evanston Northwestern Healthcare, Evanston, IL; 2. Department of Diagnostic Radiology, University of Pennsylvania, Philadelphia, PA; 3. Department of Diagnostic Radiology, Northwestern Memorial Hospital, Chicago, IL.
Address correspondence to J.W. Berlin (jonathanberlin{at}yahoo.com)
Objective: Radiology departments are increasingly seeking opportunities to increase professional revenues. A common venture pursued by radiology groups is a contract to interpret radiologic studies performed at an outpatient imaging center for a "percentage of the global fee" collected by the center. It is in the intent of this study to derive a suitable method to calculate the appropriate "percentage of global collected" to seek when pursuing these types of contracts.
Materials and Methods: The Medicare fee schedule publishes global reimbursement as well as technical and professional components of reimbursement for all radiologic procedures. Over 70% of third party payers base their reimbursement on the Medicare fee schedule, usually using a multiplier of the Medicare fee schedule to set reimbursement. To determine the appropriate percentage global approximating standard professional reimbursement using separate professional and technical billing, the professional component of reimbursement in the Medicare fee schedule was divided by the global reimbursement for the most common radiologic procedures in the four modalities of computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), and plain film radiography (X-Ray). A weighted average of expected modality mix multiplied by the percentage professional / global reimbursement for each modality was calculated to yield the appropriate percentage of global to achieve professional reimbursement equal to professional reimbursement using standard separate billing.
Results: For CT, the professional component of reimbursement comprises approximately 19% of global reimbursement. For X-Ray, the professional component of reimbursement is approximately 30% of global. For MRI, the percentage is approximately 13%, and for US the percentage is approximately 36%. Assuming expected volumes of 48% X-Ray, 16% CT, and 18% MR and US, a summed weighted average of professional component / global reimbursement multiplied by the expected modality percentage yields a desired global percentage of approximately 26%.
Conclusion: The methodology described in the study should provide radiology groups with a method to calculate an appropriate percentage of global reimbursement to seek when undertaking contracts to interpret radiologic studies in outpatient settings for a percentage of total reimbursement. This methodology can continually be reapplied as the reimbursement for procedures changes over time.
041. Can Follow-up CT of Abdomen and Pelvis Be Targeted to the Region of Interest Determined from Lesion Localization on Initial CT Study?
Sebastian S.1*; Kalra M.K.1; Sybers G.1; Mittal P.1; Small W.C.1; Hahn P.F.2; 1. Radiology, Emory University School of Medicine, Atlanta, GA; 2. Radiology, Massachusetts General Hospital, Boston, MA.
Address correspondence to S. Sebastian (Sunit.Sebastian{at}emoryhealthcare.org)
Objective: CT radiation dose is directly proportional to the scan length. The purpose of our study was to evaluate if follow-up CT of abdomen and pelvis can be targeted to the region of interest determined from lesion localization on initial CT study.
Materials and Methods: Institutional review board approved the HIPAA-compliant study protocol. In an ongoing study of 200 patients, abdominal-pelvic CT studies of 50 consecutive patients with more than one CT of abdomen and pelvis have been evaluated. Clinical diagnosis and the indication for the follow-up scan were recorded. Two abdominal radiologists independently evaluated an initial CT and a follow-up CT of each patient in three sessions. In the first session both readers reviewed the initial CT and recorded number of clinically important findings and their size, anatomic location and slice position (image numbers). In the second session, radiologists assessed targeted follow-up CT images (for only the regions where lesions were present on initial scan) for number of clinically important findings and their size and anatomic location. Subsequently, all images of follow-up CT scan (entire follow-up study) were assessed and all clinically important findings were recorded along with their size and anatomic location. Data were assessed using chi-square test.
Results: Review of initial, targeted and entire follow-up CT studies revealed 74, 74, and 79 findings (p > 0.05) respectively. Clinically important findings that were not seen on targeted CT included femoral-femoral arterial bypass thrombus, (for para-aortic hematoma evaluation), complex renal cyst (for pancreatic mass evaluation) and a liver nodule (for peripancreatic mass evaluation). Thus, targeted follow-up CT could successfully identify clinically important in 94% patients (47/50 patients).
Conclusion: In patients with focal, non-malignant diseases, follow-up abdominal-pelvic CT studies can be targeted to scan only those regions of interest where lesions were identified on initial CT. Benefits of targeted follow up CT can include radiation dose reduction and reduced interpretation time for radiologists. Actual implementation of targeted CT protocol will require vigilant pre-screening of initial CT findings. Targeted CT may not be useful to study diffuse or malignant lesions.
042. Risk-Adjusted Estimated GFR (RA-eGFR): A Simple Model for a Uniform Approach to Contrast Studies Among Radiologists
Rafat Zand K.*; Stein L.A.; Diagnostic Radiology, McGill University Health Center, Montreal, QC, Canada.
Address correspondence to K. Rafat Zand (k_r_zand{at}yahoo.com)
Objective: Critical reduction of GFR is the most important risk factor for contrast-induced nephropathy (CIN); a number of other risk factors also contribute to the outcome. However, there are inter- and intra-institutional variations of practice among radiologists on contrast issues. In our department, radiologists diverge in their approach to serum creatinine cutoffs, estimation of GFR and impact of other factors on CIN development. These differences cause scheduling disruption and reduced patient flow. Low-risk patients may be deprived of diagnostic yield of enhanced studies, while high-risk patients may be inadequately prepared, depending on rigorousness of radiologist's criteria. This also hinders research efforts as variables and outcomes can not be uniformly defined and meaningfully compared. We devised the simple model of "Risk-Adjusted estimated GFR" in an effort to address these problems.
Materials and Methods: Patient's GFR is first estimated (eGFR) using the 4-variable (creatinine, age, gender, race) MDRD formula tables; this is a fast and reliable method with no need for calculations or patient's weight. eGFR > 90 mL/min/1.73 m2 is considered normal without any need for adjustment. With eGFR < 90, additional CIN risk factors are taken into account. Recent decline in renal function, kidney disease, diabetes, heart failure and nephrotoxic drugs (including recent chemotherapy) are considered major risk factors. Poorly controlled hypertension, coronary, cerebral or peripheral vascular disease, gout and liver disease are classified as minor. For each major risk factor, eGFR is lowered equivalent to a 10 µmol/L elevation in serum creatinine (one cell in the table). The same adjustment is made for every two minor risk factors to yield Risk-Adjusted eGFR (RA-eGFR).
Results: RA-eGFR guides the decision on contrast administration and CIN-preventive measures. No preparation is necessary if RA-eGFR > 60 (KDOQI stage 1and2 disease). With 30 < RA-eGFR < 60 (stage 3), volume expansion or sodium bicarbonate is advocated, with N-Acetyl Cysteine added below 45. Contrast is best avoided with RA-eGFR < 30 (stage 4 and 5).
Conclusion: RA-eGFR uses the reliable MDRD formula, is calculation-free and independent of weight; it incorporates various CIN risk factors into pre-treatment and contrast administration decisions. RA-eGFR is a simple method that could facilitate communication between clinicians and radiologists. It can minimize inter-radiologist discrepancies in contrast-related decisions and their impact on patient safety, patient flow and research.
043. Cardiac Imaging (CI) Training in Radiology Residency Programs: A Survey of Radiology Chief Residents
Minocha J.*; Nikolaidis P.; Pyrros A.T.; Yaghmai V.; Zivin S.; Carr J.C.; Ryu R.K.; Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, IL.
Address correspondence to J. Minocha (jeet{at}md.northwestern.edu)
Objective: Cardiac imaging (CI) is currently a hot topic for both radiologists and cardiologists. Additionally, proficiency in CI is now required for certification by the American Board of Radiology. In order to ensure that future radiologists are well trained in CI, it is imperative to assess the current status of CI training in radiology residency programs. The purpose of this study is to assess the status of CI training in radiology residency programs by surveying current radiology chief residents.
Materials and Methods: Chief residents at accredited radiology residency programs were sent an e-mail with a link (www.radiology.northwestern.edu/residentsurvey) to a 17-question web-based survey. The survey assessed the organization of CI training in each residency program, role of residents on CI rotations, imaging modalities incorporated into CI training, and attitudes of residents about their CI training and the future of CI.
Results: Overall, 50 (44%) chief residents, PGY-3 to PGY-5, responded. More than half (62%) reported having at least one dedicated CI rotation during their residency. The average length of a CI rotation was 3.58 weeks. 52% and 62% of respondents had less than 5 hours of CI-related case conferences and didactic lectures per year, respectively. A large majority of responders, 86%, preferred learning about CI through a combination of both case conferences and lectures. Only 12% of respondents did not have either cardiac CT or MR incorporated into their CI training. Although 92% felt that it was important for them to be trained in CI, only 18% felt that they received adequate training in CI. Furthermore, approximately 38% would consider a fellowship in CI.
Conclusion: Extensive training in Cardiac Imaging is important for radiology residents, and the implementation of an appropriate, well-rounded teaching curriculum is essential for all radiology residency programs. At present, the majority of chief residents believe that they do not receive adequate training in CI.
* Will present paper
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