NSAID enteropathy: appearance at CT and MR enterography in the age of multi-modality imaging and treatment.

CT and MR enterography and capsule endoscopy are increasingly used as routine diagnostic tests for patients with potential small bowel disorders and obscure gastrointestinal bleeding. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used drugs that disrupt prostaglandin synthesis and result in a variety of localized complications within the small bowel ranging from ulcer formation to characteristic circumferential strictures, or diaphragms. NSAID enteropathy encompasses this spectrum of acute and chronic inflammatory sequelae, and is associated with typical findings at capsule endoscopy and surgery. Herein we review the typical clinical presentation of NSAID enteropathy, in addition to its endoscopic appearances, focusing on imaging findings at cross-sectional enterography. Multiple, short-segment strictures are the hallmarks of imaging diagnosis. Strictures may have minimal hyperenhancement or wall thickening, but these findings are typically symmetric and circumferential with respect to the bowel lumen. Multifocal Crohn's strictures, and occasionally radiation-induced strictures or adhesions, will mimic NSAID diaphragms. Multi-phase or multi-sequence imaging at CT and MR enterography increase diagnostic confidence in stricture presence. Strategies for subsequent workup and therapy after enterography are also discussed. Given the frequent use of NSAIDs and typical appearance of these strictures, knowledge of characteristic imaging findings can be particularly useful when evaluating patients with anemia and recurrent small bowel obstruction.

Diagnosis and Treatment of Isolated Cerebral Mucormycosis: Patient-Level Data Meta-Analysis and Mayo Clinic Experience.

BACKGROUND: Isolated cerebral mucormycosis is a rare and serious infection associated with intravenous drug abuse. METHODS: We performed a comprehensive meta-analysis of cases reported in studies and have included an unreported case from our institution. We searched PubMed/Medline, EMBASE, Scopus, Cochrane Databases, and our institution's electronic medical health records from inception through March 31, 2018. The cases were considered isolated (only affecting the cerebrum, cerebellum, or brainstem) if the absence of other primary sources of infection had been documented. Continuous variables were summarized using the median and interquartile range and categorical variables using frequencies and proportions. The relationships between variables were tested using the Wilcoxon rank sum and Pearson χ2 tests. RESULTS: A total of 130 studies (141 patients) met the eligibility requirements and were screened; 68 patients were included. The median age was 28 years (interquartile range, 24-38); 57% were men. Most patients had a history of intravenous drug abuse (82%), and 20% had positive human immunodeficiency virus findings. The lesion location was mostly supratentorial (91%), especially in the basal ganglia (71.2%). The cultures were positive in 38%, with Rhizopus the most common organism (59%). The mortality rate was 65%. The survivors were significantly more likely to have received amphotericin B (92% vs. 43%; P < 0.001) or to have undergone stereotactic aspiration (58% vs. 25%; P < 0.01). CONCLUSIONS: Isolated cerebral mucormycosis has a pooled mortality rate of 65%. The presence of lesions in the basal ganglia, rapidly progressive symptoms, and a history of intravenous drug abuse should raise suspicion for the early initiation of amphotericin B and stereotactic aspiration.

Low kV versus dual-energy virtual monoenergetic CT imaging for proven liver lesions: what are the advantages and trade-offs in conspicuity and image quality? A pilot study.

PURPOSE: Single-energy low tube potential (SE-LTP) and dual-energy virtual monoenergetic (DE-VM) CT images both increase the conspicuity of hepatic lesions by increasing iodine signal. Our purpose was to compare the conspicuity of proven liver lesions, artifacts, and radiologist preferences in dose-matched SE-LTP and DE-VM images. METHODS: Thirty-one patients with 72 proven liver lesions (21 benign, 51 malignant) underwent full-dose contrast-enhanced dual-energy CT (DECT). Half-dose images were obtained using single tube reconstruction of the dual-source SE-LTP projection data (80 or 100 kV), and by inserting noise into dual-energy projection data, with DE-VM images reconstructed from 40 to 70 keV. Three blinded gastrointestinal radiologists evaluated half-dose SE-LTP and DE-VM images, ranking and grading liver lesion conspicuity and diagnostic confidence (4-point scale) on a per-lesion basis. Image quality (noise, artifacts, sharpness) was evaluated, and overall image preference was ranked on per-patient basis. Lesion-to-liver contrast-to-noise ratio (CNR) was compared between techniques. RESULTS: Mean lesion size was 1.5 ± 1.2 cm. Across the readers, the mean conspicuity ratings for 40, 45, and 50 keV half-dose DE-VM images were superior compared to other half-dose image sets (p < 0.0001). Per-lesion diagnostic confidence was similar between half-dose SE-LTP compared to half-dose DE-VM images (p ≥ 0.05; 1.19 vs. 1.24-1.32). However, SE-LTP images had less noise and artifacts and were sharper compared to DE-VM images less than 70 keV (p < 0.05). On a per-patient basis, radiologists preferred SE-LTP images the most and preferred 40-50 keV the least (p < 0.0001). Lesion CNR was also higher in SE-LTP images than DE-VM images (p < 0.01). CONCLUSION: For the same applied dose level, liver lesions were more conspicuous using DE-VM compared to SE-LTP; however, SE-LTP images were preferred more than any single DE-VM energy level, likely due to lower noise and artifacts.