Margaret Lee

Multi-Institutional Reciprocal Validation Study of Computed Tomography Predictors of Suboptimal Primary Cytoreduction in Patients With Advanced Ovarian Cancer

PURPOSE Identify features on preoperative computed tomography (CT) scans to predict suboptimal primary cytoreduction in patients treated for advanced ovarian cancer in institution A. Reciprocally cross validate the predictors identified with those from two previously published cohorts from institutions B and C. PATIENTS AND METHODS Preoperative CT scans from patients with stage III/IV epithelial ovarian cancer who underwent primary cytoreduction in institution A between 1999 and 2005 were retrospectively reviewed by radiologists blinded to surgical outcome. Fourteen criteria were assessed. Crossvalidation was performed by applying predictive model A to the patients from cohorts B and C, and reciprocally applying predictive models B and C to cohort A. RESULTS Sixty-five patients from institution A were included. The rate of optimal cytoreduction ( 1 cm residual disease) was 78%. Diaphragm disease and large bowel mesentery implants were the only CT predictors of suboptimal cytoreduction on univariate (P < .02) and multivariate analysis (P < .02). In combination (model A), these predictors had a sensitivity of 79%, a specificity of 75%, and an accuracy of 77% for suboptimal cytoreduction. When model A was applied to cohorts B and C, accuracy rates dropped to 34% and 64%, respectively. Reciprocally, models B and C had accuracy rates of 93% and 79% in their original cohorts, which fell to 74% and 48% in cohort A. CONCLUSION The high accuracy rates of CT predictors of suboptimal cytoreduction in the original cohorts could not be confirmed in the cross validation. Preoperative CT predictors should be used with caution when deciding between surgical cytoreduction and neoadjuvant chemotherapy.

Multistation Whole-Body High- Spatial-Resolution MR Angiography Using a 32-Channel MR System

OBJECTIVE The objective of our study was to investigate a multistation whole-body MR angiography (MRA) protocol using a 32-channel MR system with multicoil technology in a population of patients with suspected peripheral vascular disease (PVD). SUBJECTS AND METHODS Fifty consecutive patients with suspected PVD (31 men, 19 women; age range, 46-91 years) underwent multistation whole-body contrast-enhanced MR angiography (CE-MRA) on a 32-channel 1.5-T MR system equipped with multicoil technology. A two-step contrast injection protocol was used: After the first injection, images of the most proximal station (station I, head and neck) were acquired, followed by the most distal station (station IV, calves). Images of the intermediate two stations (station II, chest and abdomen; station III, pelvis and thighs) were acquired during the second injection. Conventional catheter angiography was performed for symptomatic vascular regions in 30 patients. The image quality of the arterial segments and the presence and degree of the arterial stenosis were evaluated by two radiologists. The interobserver variability was calculated by kappa statistics, and comparative analysis between CE-MRA and catheter angiography was performed by means of the Spearmans rank correlation coefficient. RESULTS Most of the vascular segments (1,912/1,976 [97%]) were visualized on wholebody CE-MRA with diagnostic image quality. Significant arterial disease (> or = 50%) was detected in 167 (observer 1) and 177 (observer 2) segments with excellent interobserver agreement (kappa = 0.84). There was a significant correlation between CE-MRA and conventional angiography for the degree of stenosis (R = 0.92 and 0.89 for observers 1 and 2, respectively). The sensitivity and specificity of CE-MRA for the detection of arterial stenoses 50% or greater were 92% and 96% for observer 1 and 93% and 97% for observer 2, respectively, compared with those of conventional angiography. CONCLUSION Using a multichannel radiofrequency system with multicoil technology, the whole-body CE-MRA approach outlined in this article is able to provide high-spatial-resolution data sets with high diagnostic image quality for evaluation of arterial occlusive disease in most vascular territories.

High-Spatial-Resolution Contrast-Enhanced MR Angiography of Abdominal Arteries with Parallel Acquisition at 3.0 T: Initial Experience in 32 Patients

OBJECTIVE The objective of our study was to evaluate an isotropic high-spatial-resolution 3D contrast-enhanced MR angiography (CE-MRA) protocol with high acceleration parallel acquisition at 3.0 T for the display of the abdominal vasculature. SUBJECTS AND METHODS Thirty-two consecutive patients (13 men, 19 women; age range, 28-88 years) with suspected abdominal arterial disease underwent abdominal 3D CE-MRA on a 3.0-T MR system, using a high-spatial-resolution (0.7 x 0.82 x 0.8 mm3) 3D gradient-refocused echo (GRE) sequence, integrated with a generalized autocalibrating partially parallel acquisitions (GRAPPA) technique with an acceleration factor of 3. Two vascular radiologists evaluated image quality and the presence and degree of arterial stenoses. Interobserver variability was calculated, using the kappa coefficient. The sensitivity and specificity of the technique were calculated and comparative analysis was performed with those of conventional catheter angiography (in eight patients) as the standard of reference. RESULTS The abdominal arterial vasculature was visualized with diagnostic image quality in all subjects. Arterial stenoses were detected in 148 and 142 arterial segments by observer 1 and observer 2, respectively, with good interobserver agreement (kappa = 0.75; 95% confidence interval [CI]: 0.69-0.81). The sensitivity and specificity values for CE-MRA for the detection of significant (> 50%) arterial stenoses were 100% and 96% for observer 1 and 100% and 92% for observer 2, respectively. There was a significant correlation between CE-MRA and conventional angiography (R = 0.96 and 0.93 for observers 1 and 2, respectively) for the assessment of the degree of stenosis. CONCLUSION The outlined MR angiography protocol at 3.0 T combined with parallel acquisition technique renders highly reliable and isotropic high-spatial-resolution imaging of the abdominal vasculature.

Dynamic pulmonary perfusion and flow quantification with MR imaging, 3.0T vs. 1.5T: Initial results

To prospectively evaluate the technical feasibility and relative performance of pulmonary time‐resolved MR angiography (MRA) and pulmonary artery (PA) flow quantification at 3.0T vs. 1.5T.

MDCT of left anterior descending coronary artery to main pulmonary artery fistula.

4Imaging Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA. ost coronary artery fistulas are congenital in origin, but they have been reported to be acquired as complications of chest trauma, coronary angioplasty, and bypass surgery. These fistulas are usually discovered incidentally on coronary angiography or are found at autopsy, because most patients are initially asymptomatic. Some, however, may present with congestive heart failure. Visualization of coronary fistulas has recently been reported using 3D CT in a cadaveric specimen [1]. We present a case of a fistulous communication between the left anterior descending artery and the main pulmonary artery as seen on MDCT in a patient with a medical history of myocardial infarction and percutaneous transluminal coronary angioplasty and a history of penetrating chest injury. Reconstructed images obtained on MDCT are illustrated with correlative angiographic images. To our knowledge, this is the first report of an evaluation of a coronary artery fistula using MDCT in the English-language literature.

MR-guided procedures using contemporaneous imaging frameless stereotaxis in an open-configuration system

Frameless MR-guided procedures have had limited application using conventional closed magnets, due largely to the technical difficulties involved. As a result of in-room MR image-monitoring capabilities, new open-design magnets now allow frameless stereotaxis using contemporaneous imaging to guide more invasive procedures. We evaluate our clinical experience with this new technique. An open-design 0.2 T magnet (Siemens OPEN) combined with an in-room monitor was used for 33 frameless MR-guided procedures (aspiration cytology, biopsy, and/or treatment) in a variety of locations in the head, neck, spine, brain, pelvis, and abdomen. Success of the procedure was based on the ability to accurately position the instrument in the target region to allow biopsy and/or treatment. The open-design magnet allowed the physician to directly access the patient for frameless stereotaxis as the procedure was performed. The in-room monitor provided contemporaneous imaging feedback during the procedure for successful placement of the instrument in the target region. Twenty-eight biopsy and five treatment procedures were performed. In all cases the technique resulted in successful placement of the instrument within the target tissue to complete the procedure. MR-guided procedures using contemporaneous imaging frameless stereotaxis are possible in an open-design magnet with in-room image monitoring and offer exciting possibilities for further development.

Conditional Survival of Patients With Metastatic Testicular Germ Cell Tumors Treated With First-Line Curative Therapy

PURPOSE The International Germ Cell Cancer Collaborative Group (IGCCCG) criteria prognosticate survival outcomes in metastatic testicular germ cell tumor (MT-GCT), but how the initial risk changes over time for those who survived since curative treatment is unknown. PATIENTS AND METHODS We assessed patients eligible for first-line therapy for MT-GCT at five tertiary cancer centers from 1990 to 2012 for 2-year conditional overall survival (COS) and conditional disease-free survival (CDFS), defined as the probability of surviving, or surviving and being disease free, respectively, for an additional 2 years at a given time point since the initial diagnosis. RESULTS For all patients (N = 942), 2-year COS increased from 92% (95% CI, 91% to 94%) at 0 months to 98% (95% CI, 97% to 99%), and 2-year CDFS increased from 83% (95% CI, 81% to 86%) at baseline to 98% (95% CI, 97% to 99%) at 24 months after diagnosis. Two-year COS improved by 2% (97% at 0 months, 99% at 24 months) in the IGCCCG favorable-risk group, by 5% (94% at 0 months, 99% at 24 months) in the intermediate-risk group, and by 22% (71% at 0 months to 93% at 24 months) in the poor-risk group. Two-year CDFS improved significantly at 12 months for each risk group (favorable, 91% baseline v 95% at 12 months; intermediate, 84% v 95%; poor, 55% v 85%). Baseline IGCCCG risk stratification was not associated with long-term COS or CDFS for patients who survived to greater than 2 years post therapy. No significant differences in COS and CDFS were noted between seminoma and nonseminoma; patients ≥ 40 years old had inferior 2-year COS from 0 to 12 months, but no differences were noted at 18 months. CONCLUSION Our data suggest that the concept of conditional survival applies to patients with MT-GCT treated with curative therapy. Patients with MT-GCT who survived and remained disease free more than 2 years after the diagnosis had an excellent chance of staying alive and disease free in additional subsequent years, regardless of the initial IGCCCG risk stratification.

Transcatheter arterial embolotherapy: a therapeutic alternative in obstetrics and gynecologic emergencies.

Transcatheter arterial embolization has become a major treatment modality in a variety of clinical applications, including management of bleeding related to a broad spectrum of obstetric and gynecologic disorders. Embolotherapy has a well-documented role in the management of pelvic and genital tract hemorrhage in the postpartum and postoperative/postcesarean setting. It is also an integral part in the treatment armamentarium of abdominal and cervical ectopic pregnancy, arteriovenous malformation, and gynecologic neoplasms, including more recently, uterine leiomyomata. Based on experiences accumulated over the past decades, embolotherapy has been proven to be highly effective with success rate in the 90 to 100% range in the appropriate clinical settings. It provides visualization of the bleeding site and enables targeted, minimally invasive therapy to achieve hemostasis, which allows preservation of the uterus and hence fertility. In hospitals where experienced personnel and technology is available, transcatheter arterial embolization should be considered in the emergent management of obstetric and gynecologic hemorrhage, particularly when local and conservative measures fail to attain hemostasis.

ACR Appropriateness Criteria® Abdominal Aortic Aneurysm: Interventional Planning and Follow-Up.

Abdominal aortic aneurysms (AAAs) are a relatively common vascular problem that can be treated with either open, surgical repair or endovascular aortic aneurysm repair (EVAR). Both approaches to AAA repair require dedicated preoperative imaging to minimize adverse outcomes. After EVAR, cross-sectional imaging has an integral role in confirming the successful treatment of the AAA and early detection of complications related to EVAR. CT angiography is the primary imaging modality for both preoperative planning and follow-up after repair. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

WE‐A‐218‐10: The Tradeoff between Diagnostic Performance and Radiation Dose for CT Imaging in the Diagnosis of Appendicitis Across Observers with Various Levels of Experience

Purpose: To investigate the tradeoffs between radiationdose and diagnostic performance in CT for a challenging clinical task (diagnosis of appendicitis). Methods: This IRB approved study utilized data for 20 patients undergoing clinical CT exams for indications of appendicitis. Medical records were reviewed to establish true diagnosis and identified 10 positive and 10 negative cases. Original (100%) and simulated reduced dose levels (70%, 50%, 30%, 20% of original) were created with a validated software tool using raw projection data from each scan. An observer study was performed with 6 radiologists (of different training and cross‐sectional reading experience) reviewing each case at each dose level in stratified random order over several sessions. Readers assessed image quality and provided confidence in their diagnosis of appendicitis, each on a 5 point scale. Receiver Operating Characteristics (ROC) curves were generated for each dose level using all rating levels and from the resulting ROC curves, the AUC (Area under curve) was calculated for each dose level. This analysis was repeated for groups of readers with different experience levels. Results: The ROC curves averaged over all 6 observers and corresponding AUC values showed indifferent performances for all the dose levels. For the 2 non‐abdominal trained, occasional CT readers, the performance did not decrease until 30% dose level. For the 2 non‐abdominal trained, routine CT readers, the performance did not decrease until 20% dose level. For the 2 abdominal trained, routine CT readers, the performance is consistent across all the dose levels. Conclusions: This preliminary study demonstrated the tradeoffs between radiationdose and diagnostic performance and indicated that: (a) There is essentially no difference between diagnostic performance of 100%, 70%, and 50% dose level for all 6 observers. (b) For abdominal CT specialists, the diagnostic difference is not substantially compromised even at 20% dose levels. (c) For non‐abdominal trained CT readers, the performance declines at 30% and 20% dose levels. For Michael McNitt‐ Gray: Institutional research agreement, Siemens AG Recipient research support Siemens AG