Postoperative Elevated Resistive Indices Do Not Predict Hepatic Artery Thrombosis in Extended Criteria Donor Livers.

Postoperative transplant liver ultrasounds were analyzed in standard criteria donor (SCD), extended criteria donor (ECD), and donation after cardiac death (DCD) liver allografts to determine if elevated resistive indices (RIs) are consistently present and if they are pathological. Postoperative transplant liver ultrasounds were reviewed from 115 consecutive patients. Hepatic arterial RIs were stratified based on the type of donor: DCD, macrosteatosis (>30%), or standard criteria. In all patients with elevated RI, subsequent ultrasounds were reviewed to demonstrate RI normalization. The mean RI for all 115 patients was 0.64, DCD was 0.67, macrosteatosis was 0.81, and SCD was 0.61 ( p = 0.033). The RI on subsequent liver ultrasounds for DCD and macrosteatosis normalized without any intervention. There were no incidences of early hepatic artery thrombosis (HAT) observed in the cohort. Hepatic arterial RI in ECDs and DCDs are elevated in the immediate postoperative period but are not predictive of HAT. It represents interparenchymal graft stiffness and overall graft edema rather than an impending technical complication. The results of our study do not support the routine use of anticoagulation or routine investigation with computed tomography angiography for elevated RIs as these findings are self-limiting and normalize over a short period of time. We hope that this information helps guide the clinical management of liver transplant patients from expanded criteria donors.

Magnetic resonance enterography: state of the art.

Crohn's disease is a chronic inflammatory bowel disease of the gastrointestinal tract manifested by frequent periods of relapses and remissions of symptoms. The small bowel is most frequently affected. Progression of transmural inflammation can lead to stricturing or penetrating complications. At the time of diagnosis, approximately 10% of patients have disease beyond the reach of the colonoscope. Imaging can aid in clinical evaluation by depicting small bowel involvement and extraenteric disease. Magnetic resonance enterography (MRE) has emerged as a valuable tool and is being used with increasing frequency for the diagnosis and management of Crohn's disease. This article will discuss the current state of the art in MRE. In addition to reviewing the literature reporting its utility, we will present case examples illustrating how MRE best depicts the various findings of Crohn's disease within 4 imaging categories of disease: active inflammatory, fibrostenotic, fistulizing/perforating, and reparative or regenerative. We will present additional important clinical considerations in routine use of MRE, including implications for monitoring disease activity and response to treatment, cost-effectiveness, and appropriate use in the context of the American College of Radiology Appropriateness Criteria.

Anti-TNF therapy is associated with decreased imaging and radiation exposure in patients with Crohn's disease.

BACKGROUND: Diagnostic imaging is frequently used in Crohn's disease (CD) for diagnosis, evaluation of complications, and determination of response to treatment. Patients with CD are at risk for high radiation exposure in their lifetime. The aim of our study was to compare the effective dose of radiation in CD patients the year prior to and the year after initiation of anti-tumor necrosis factor (anti-TNF) agents or corticosteroids. METHODS: We conducted a retrospective review of 99 CD patients initiated on anti-TNF therapy or corticosteroids between 2004 and 2009 in a tertiary care center. RESULTS: Sixty-five patients were initiated on anti-TNF agents and 34 were initiated on corticosteroids. The anti-TNF cohort was significantly younger at diagnosis and at the time of initiation of anti-TNF or steroid therapy. The anti-TNF group had significantly more stricturing, penetrating, and perianal disease than the corticosteroid group. The anti-TNF cohort had a significant reduction in number of radiologic exams (5.5 vs. 3.7, P < 0.01) as well as a significant reduction in the cumulative radiation dose (28.1 vs. 15.0 mSv, P < 0.01) the year after initiation of therapy. This reduction was largely attributable to decreased use of computed tomography (CT) scans. In contrast, there was no significant change in radiation exposure in the corticosteroid cohort. Logistic regression analysis showed a strong trend toward higher exposure in patients with complicated disease behavior (stricturing or penetrating phenotype) (odds ratio [OR] 2.87, 95% confidence interval [CI] 0.98-8.38). CONCLUSIONS: Initiation of anti-TNF therapy for treatment of CD is associated with a significant reduction in diagnostic radiation exposure. Conversely, steroid treatment does not reduce diagnostic radiation exposure.

Imaging of whole-organ pancreas transplants.

Whole pancreas transplantation is an established treatment for selected patients with diabetic nephropathy or poorly controlled diabetes. Surgical techniques vary and have evolved over the past 4 decades. Imaging evaluation of the whole-pancreas transplant should begin with an understanding of the most commonly used surgical techniques and the spectrum of postoperative complications. Ultrasonography (US) should be the first-line modality in evaluating the pancreas allograft and vasculature. Computed tomography (CT) is useful in the assessment of extra-allograft processes, particularly in ruling out abscess formation or evaluating suspected bowel complications. Magnetic resonance (MR) imaging is reserved for cases in which complete evaluation with US or CT is not possible. MR angiography can help provide an accurate assessment of vascular abnormalities. The radiologist must be familiar with the spectrum of surgical techniques and the normal postoperative imaging appearances of the whole-pancreas transplant so as to be able to recognize abnormal postoperative findings. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.322115144/-/DC1.

Comparison of sagittal T2-weighted BLADE and fast spin-echo MRI of the female pelvis for motion artifact and lesion detection.

OBJECTIVE: The objective of this study was to evaluate the effectiveness of BLADE (proprietary name for periodically rotated overlapping parallel lines with enhanced reconstruction [PROPELLER] in MR systems from Siemens Healthcare) MRI compared with conventional T2-weighted fast spin-echo (FSE) MRI for reducing artifacts and improving image quality when imaging the female pelvis. MATERIALS AND METHODS: Sagittal T2-weighted BLADE and FSE examinations of the pelvis of 26 women were performed on a 1.5-T scanner. Three radiologists assessed the images for the presence of artifacts, level of anatomic detail, and overall image quality using a modified Likert scale. Scores for each radiologist and each imaging sequence were analyzed with a linear mixed model, adjusting for correlation within radiologist and within patient. A quantitative comparison was conducted to investigate signal uniformity. RESULTS: The BLADE sequence was superior for evaluation of the junctional zone (p = 0.0019), delineation of ovarian borders and depiction of follicles (p < 0.0001), and detection of fibroids (p = 0.022). Overall image quality was improved with BLADE, with fewer respiratory motion artifacts. The BLADE sequence introduced "radial" artifact that was absent from the FSE images, but this artifact did not affect image quality. Quantitative analysis revealed mean coefficients of variation for BLADE and FSE in the uterus of 21.6% and 22.5%, respectively (p = 0.36). The mean coefficients of variation were 4.6% and 6.1% in fat (p = 0.0007), indicating less variation with BLADE. The mean acquisition times for the BLADE and FSE sequences were 4 minutes 31 seconds and 3 minutes 46 seconds, respectively. CONCLUSION: Imaging of uterine junctional zone anatomy, ovaries, and fibroids was improved and artifacts were reduced with BLADE compared with FSE. Radial artifact introduced by the BLADE sequence and slightly longer imaging times needed for the BLADE sequence were offset by improved image quality.

Imaging of acute pelvic pain.

Determining the cause of acute pelvic pain in the female patient is often a clinical challenge. Diagnostic imaging can be invaluable in this situation. Ectopic pregnancy, pelvic inflammatory disease, and hemorrhagic ovarian cysts are the most commonly diagnosed gynecologic conditions presenting with acute pelvic pain. Ovarian torsion and degenerating fibroids occur less frequently. Other causes to consider include endometriosis, and postpartum causes such as endometritis, or ovarian vein thrombosis. Finally, nongynecologic conditions may overlap in their presentation of acute pelvic pain and should also be considered. The most important of these is acute appendicitis.

Breast MRI: state of the art.

Magnetic resonance imaging (MRI) of the breast has emerged as a useful adjunct in evaluation of breast disease. For the past 25 years its use has been explored extensively in the literature and specific clinical indications have been developed. This review will address the current state of the art of breast MRI, including image acquisition, interpretation, limitations, and current applications. We also will discuss briefly emerging techniques that may further advance the practice of breast MRI evaluation.