Pulmonary Mucormycosis: Risk Factors, Radiologic Findings, and Pathologic Correlation.

Pulmonary mucormycosis (PM) is an uncommon fungal infection most often seen in immunocompromised patients. The fungus grows on decaying food, soil, and animal excrement. Patients usually become infected by inhalation of spores. The most common risk factors include diabetes mellitus, hematologic malignancy, and solid organ or stem cell transplant. PM can have a nonspecific appearance at imaging. For example, early imaging may show peribronchial ground-glass opacity. Later, the disease progresses to consolidation, nodules, or masses. Because patients are usually immunocompromised, the differential diagnosis often includes invasive pulmonary aspergillosis (IPA). Various radiologic findings suggestive of PM have been identified to help differentiate it from IPA. For example, the reverse halo sign is more closely associated with PM than with IPA. The reverse halo sign is an area of ground-glass opacity surrounded by a rim of consolidation. In addition, the presence of pleural effusions and more than 10 nodules is more suggestive of PM than it is of IPA. PM can progress rapidly in neutropenic patients. Identification of the hyphae in tissue by using endobronchial or percutaneous sampling can allow differentiation from IPA and help confirm the diagnosis of mucormycosis. Because of the high mortality rate associated with PM, early identification of the disease is critical for an improved likelihood of survival. A multimodality treatment approach with antifungal agents and surgical débridement has been shown to improve outcomes. The authors review the risk factors for PM, describe its imaging appearance and disease process, and describe the treatment of the disease. ©RSNA, 2020.

Integration of fully automated computer-aided pulmonary nodule detection into CT pulmonary angiography studies in the emergency department: effect on workflow and diagnostic accuracy.

PURPOSE: To assess the feasibility of implementing fully automated computer-aided diagnosis (CAD) for detection of pulmonary nodules on CT pulmonary angiography (CTPA) studies in emergency setting. MATERIALS AND METHODS: CTPA of 48 emergency patients was retrospectively reviewed. Fully automated CAD nodule detection was performed at the scanner and results were automatically submitted to PACS. A third-year radiology resident (RAD1) and a cardiothoracic radiologist with 6 years' experience (RAD2) reviewed the scans independently to detect pulmonary nodules in two different sessions 8 weeks apart: session 1, CAD was reviewed first and then all images were reviewed; session 2, CAD was reviewed last after all images were reviewed. Time spent by RAD to evaluate image sets was measured for each case. Fisher's exact test and t test were used. RESULTS: There were 17 male and 31 female patients with mean ± SD age of 48.7 ± 16.4 years. Using CAD at the beginning was associated with lower average reading time for both readers. However, difference in reading time did not reach statistical significance for RAD1 (RAD1 94.6 s vs. 102.7 s, P > 0.05; RAD2 61.1 s vs. 76.5 s, P < 0.05). Using CAD at the end significantly increased rate of RAD1 and RAD2 nodule detection by 34% (2.52 vs. 2.12 nodule/scan, P < 0.05) and 27% (2.23 vs. 1.81 nodule/scan, P < 0.05), respectively. CONCLUSION: Routine utilization of CAD in emergency setting is feasible and can improve detection rate of pulmonary nodules significantly. Different methods of incorporating CAD in detecting pulmonary nodules can improve both the rate of detection and interpretation speed.

Significance of elevated transplant renal artery velocities in the postoperative renal transplant patient.

INTRODUCTION: Non-invasive imaging studies can provide visualization of allograft perfusion in the postoperative evaluation of newly transplanted renal allografts. AIM: The purpose of our study was to evaluate the significance of elevated renal artery velocities in the immediate postoperative period. METHODS: Peak systolic velocities (PSVs) were obtained in the transplanted renal artery of 128 patients immediately after transplantation. Repeat allograft Doppler ultrasonography was performed on patients with elevated values. RESULTS: Of the 128 patients, 57 (44.5%) had severely elevated Doppler velocities >400 cm/s on the initial studies. Three patients within this category had persistently elevated values of >400 cm/s, warranting angiographic visualization of the renal vessels. Stent placement within the transplanted renal artery was required in two of these patients. There was normalization of the PSV in the remaining patients. CONCLUSIONS: Routine allograft Doppler ultrasonography in the immediate postoperative period allows for visualization of allograft perfusion. Elevated renal artery velocities in the immediate postoperative period do not necessarily represent stenosis requiring intervention. Failure of the PSV to normalize may require further intervention, and angiography continues to be the gold standard.

Synthesis, isolation, characterization, and reactivity of high-energy stereogenic-at-Ru carbenes: stereochemical inversion through olefin metathesis and other pathways.

The synthesis, isolation, purification (routine silica gel chromatography), and spectroscopic characterization of high-energy endo stereogenic-at-Ru complex isomers, generated by ring-opening/cross-metathesis (ROCM) reaction of the corresponding exo carbenes, are disclosed. We provide experimental evidence showing that an endo isomer can undergo thermal or Brønsted acid-catalyzed polytopal rearrangement, causing conversion to the energetically favored exo carbene.

Updates in Magnetic Resonance Venous Imaging.

For years, magnetic resonance angiography (MRA) has been a leading imaging modality in the assessment of venous disease involving the pelvis and lower extremities. Current advancement in noncontrast MRA techniques enables imaging of a larger subset of patients previously excluded due to allergy or renal insufficiency, allowing for preintervention assessment and planning. In this article, the current status of MR venography, with a focus on current advancements, will be presented. Protocols and parameters for MR venographic imaging of the pelvis and lower extremities, including contrast and noncontrast enhanced techniques, will be reviewed based on a recent literature review of applied MR venographic techniques. Finally, several disease-specific entities, including pelvic congestion and compression syndromes, will be discussed with a focus on imaging parameters that may best characterize these disease processes and optimize anatomical planning prior to intervention.

Evaluation of Renal Allograft Vasculature Using Non-contrast 3D Inversion Recovery Balanced Steady-state Free Precession MRA and 2D Quiescent-interval Slice-selective MRA.

BACKGROUND AND OBJECTIVES: Renal transplant patients often require periodic imaging to evaluate the transplant vessel anastomosis for potential vascular complications. The use of non-contrast enhanced magnetic resonance angiography (NCE-MRA) techniques is encouraged in these patients because they are at increased risk of nephrogenic systemic fibrosis (NSF) due to their renal insufficiency. This study aimed to evaluate the performance of two NCE-MRA techniques (three-dimensional [3D] balanced steady-state free precession [bSSFP] with inversion recovery and quiescent-interval slice-selective [QISS]) for the evaluation of renal allograft vasculature in patients with clinical suspicion, or Doppler ultrasound, or both of arterial anastomotic stenosis. METHODS: A total of 43 patients were included in this retrospective study. Two radiologists independently scored the images from 3D bSSFP and QISS MRA sequences for image quality and confidence in anastomosis interpretation, and the degree of stenosis at the arterial anastomosis. Correlations with digital subtraction angiography (DSA) were carried out when available. In addition, inter-rater agreement was calculated. RESULTS: In total, 43 patients underwent QISS and 3D bSSFP MRA. For QISS, all cases were adequate for evaluation. For 3D SSFP, 86% of cases were adequate for evaluation. There was a good-to-excellent inter-rater agreement for all scores and an excellent correlation between NCE-MRA and DSA results when available (12 patients). CONCLUSIONS: QISS and 3D SSFP showed good inter-rater agreement for image quality and stenosis grade, with more cases being of adequate image quality that used QISS. Further study is required; however, NCE-MRA shows potential as a risk-free alternative to CTA and contrast-enhanced MRA (CE-MRA) for the evaluation of arterial anastomoses in renal transplant patients.

H-bonding as a control element in stereoselective Ru-catalyzed olefin metathesis.

H-bonding interactions have been exploited extensively in the design of catalysts for stereoselective synthesis but have rarely been utilized in the development of metal-catalyzed processes. Studies described herein demonstrate that intramolecular H-bonding interactions can significantly increase the rate and levels of stereochemical control in Ru-catalyzed olefin metathesis reactions. The utility of H-bonding in catalytic olefin metathesis is elucidated through development of exceptionally facile and highly diastereoselective ring-opening/cross-metathesis (DROCM) reactions, involving achiral Ru catalysts and enantiomerically enriched allylic alcohols. Transformations proceed to completion readily (> 98% conversion, up to 87% yield), often within minutes, in the presence of < or = 2 mol % of an achiral catalyst to afford synthetically versatile products of high stereochemical purity (up to > 98:2 dr and 11:1 E:Z).

A randomized control trial evaluating the educational effectiveness of a rapid HIV posttest counseling video.

OBJECTIVE: Many of the individuals most at risk for HIV infection (i.e., minority populations, women, adolescents) are also the most marginalized by our health care system. Lacking primary care providers, they rely on the Emergency Department (ED) for their health care needs and education. In this prospective randomized controlled trial, we compared the educational effectiveness of a 15-minute posttest counseling video with the normal practice of a session with an HIV counselor. The study population was composed of ambulatory patients recruited for rapid HIV testing in the ED. METHODS: The RAs (research assistants) recruited a convenience sample of stable patients presenting to the walk-in section of an inner-city adult ED for rapid HIV testing. Eligible patients for this study included patients who consented for the rapid HIV test and completed measures on condom intention and condom use self-efficacy. Before receiving their results, participants who consented to be in this study were randomized to either a 15-minute HIV posttest educational video available in English/Spanish or to a posttest educational session with an HIV counselor. Afterwards, both groups completed an assessment tool concerning HIV prevention and transmission. RESULTS: Of the 128 participants, 61 and 67 patients were randomized to the video and counselor groups, respectively. The groups were similar with respect to gender, ethnicity and experience with prior HIV testing. Mean knowledge scores were higher in the video group (76.20% vs. 69.3%; 90% CI for the difference, 2.8, 11.2). As the lower bound of the CI for the difference was higher than the lower equivalence boundary (-5%), we infer that the video was at least as effective as the counselor educational session. CONCLUSIONS: The use of an educational counseling video is a valid alternative for providing posttest education and prevention information during the waiting period associated with the 20-minute HIV rapid test. Without disruption in clinical flow, both testing and education can be accomplished in a meaningful way in a busy ED.

An efficient asymmetric synthesis of manzacidin C.

A brief synthesis of manzacidin C based on a chiral silane-promoted diastereo- and enatioselective acylhydrazone-alkene [3 + 2] cycloaddition reaction has been achieved. This synthesis is the first synthesis of any of the manzacidins wherein the C(4) and C(6) stereocenters are established in a single highly stereoselective step.

Highly diastereo- and enantioselective reagents for aldehyde crotylation.

Two new, crystalline solid, storable, and highly enantioselective reagents for aldehyde crotylation have been developed. Both (cis and trans) crotylsilane reagents are easily prepared in bulk, require trivial reaction conditions, and provide the homoallylic alcohol products with near diastereo- and enantiospecificity in many cases.

A program director's guide to the Medical Student Performance Evaluation (former dean's letter) with a database.

PURPOSE: The value of the Medical Student Performance Evaluation (MSPE) for a program director is in the information it contains comparing how a student performed in medical school relative to his or her classmates. The Association of American Medical Colleges has recommended that a student's class ranking be included in the summary paragraph of the MSPE and that this information be repeated in a supplementary appendix. METHODS: The authors reviewed the MSPEs from 1,479 applications for residency training positions. The aim was to determine to what extent and in what manner individual schools reveal how their students perform relative to their peers. The authors then set out to create a database containing this information. RESULTS: Working from a list of 141 US members of the Association of American Medical Colleges, complete information for 107 schools (76%) and partial information for the remaining 34 schools (24%) was gathered. Only 12 schools (9%) included complete comparative information in the summary section in accordance with the guidelines of the Association of American Medical Colleges. Other schools were in partial compliance or did not comply at all. The database the authors constructed will inform users if comparative information is available, guide users to its location in the MSPE, and explain the meaning of the language different schools use to rank or classify their students. CONCLUSIONS: The authors recognize that this database is incomplete and that the individual institutions will alter their ranking system from time to time. But this database is offered in an open format so that it can be continuously updated by users.

A simple and general chiral silicon Lewis acid for asymmetric synthesis: highly enantioselective [3+2] acylhydrazone-enol ether cycloadditions.

A highly diastereo- and enantioselective [3 + 2] acylhydrazone-enol ether cycloaddition mediated by a simple chiral silane Lewis acid is described. The reactions are highly practical, as demonstrated by a larger scale (5 g of the hydrazone) reaction in which the product was obtained after recrystallization in 93% yield and 99% ee. Evidence for a stepwise mechanism and a model for the asymmetric induction are presented, as well.