A meta-analysis of the performance of ultrasound, hepatobiliary scintigraphy, CT and MRI in the diagnosis of acute cholecystitis.

PURPOSE: To evaluate the recently reported relative diagnostic accuracy of US, CT, MRI, and cholescintigraphy for diagnosing acute cholecystitis. METHODS: 2 radiologists independently performed systematic electronic searches for articles published between 2000 and 2021 and applied inclusion/exclusion criteria. 2 different radiologists extracted data from the articles and scored each with a methodological quality tool. Pooled estimates of sensitivity and specificity were calculated with a bivariate linear mixed model. A second analysis made head-to-head comparisons (US vs. CT, US vs. cholescintigraphy). Factors were also analyzed for potential confounding effects on diagnostic accuracy. RESULTS: Of 6121 initial titles, 22 were included. The prevalence of cholecystitis varied widely across studies (9.4-98%). Pooled sensitivity and specificity estimates were 69% (confidence limit [CL] 62-76%) and 79% (CL 71-86%) for US, 91% (CL 86-94%) and 63% (CL 51-74%) for cholescintigraphy, 78% (CL 69-84%) and 81% (CL 71-88%) for CT, and 91% (CL 78-97%) and 93% (CL 70-99%) for MRI. Regarding head-to-head comparisons, the sensitivity of CT (87.6%, CL 70-96%) was significantly higher than US (66.8%, CL 43-84%), while specificities (81.7% with CL 54-95% for US, 91.9% with CL 67-99% for CT) were similar. The sensitivity of cholescintigraphy (87.4%, CL 76-94%) was significantly greater than US (61.6%, CL 44-77%), while the specificity of US (82%, CL 65-92%) was significantly higher than cholescintigraphy (68%, CL 47-84%). CONCLUSION: Recent data suggests that CT may have a higher sensitivity than US for diagnosing acute cholecystitis, with similar specificity. Cholescintigraphy remains a highly sensitive modality with lower specificity than previously reported. MRI remains under studied, but with promising results.

Mitochondrial membrane model: Lipids, elastic properties, and the changing curvature of cardiolipin.

Mammalian and Drosophila melanogaster model mitochondrial membrane compositions are constructed from experimental data. Simplified compositions for inner and outer mitochondrial membranes are provided, including an asymmetric inner mitochondrial membrane. We performed atomistic molecular dynamics simulations of these membranes and computed their material properties. When comparing these properties to those obtained by extrapolation from their constituting lipids, we find good overall agreement. Finally, we analyzed the curvature effect of cardiolipin, considering ion concentration effects, oxidation, and pH. We draw the conclusion that cardiolipin-negative curvature is most likely due to counterion effects, such as cation adsorption, in particular of H3O+. This oft-neglected effect might account for the puzzling behavior of this lipid.

Emergent colectomy for colorectal cancer: A comparative analysis of open vs. minimally invasive approach.

INTRODUCTION: Emergent surgery for colorectal cancer (CRC) is associated with higher rates of morbidity and mortality and outcomes differ by surgical approach. METHODS: Our study compares short-term surgical outcomes of patients undergoing emergent colectomy for CRC using the open vs minimally invasive (MIS) approach. We performed a four-year review (2012-2015) of the ACS-NSQIP Colectomy dataset and included all adult patients with CRC who underwent emergent surgical intervention. Patients were stratified into groups based on surgical approach: Open and MIS (including laparoscopic and robotic). RESULTS: A total of 1855 (MIS: 279, Open: 1576) patients were included. Outcome measures were operative time, 30-day complications, 30-day readmission, and 30-day mortality. Multivariate Regression analysis was performed. Patients in the open group were more likely to be older (70y vs. 61y, p < 0.01), have higher ASA class, and were less likely to have received mechanical bowel preparation. On univariate analysis, patients in the MIS group had longer operative time (189 ± 41 min vs. 161 ± 69 min, p < 0.01). Patients in the open group had higher rates of mortality (6.7% vs. 3.8%, p < 0.01) and 30-day complications (28.1% vs. 16.7%, p < 0.01). On regression analysis, the open approach was independently associated with higher odds of 30-day mortality and 30-day complications. CONCLUSION: Given the lower overall mortality and complications, MIS colectomy may be a safer approach in the emergent treatment of patients with colorectal cancer.

Imaging and clinical assessment of functional defecatory disorders with emphasis on defecography.

Functional defecation disorders (FDD) encompass causes of constipation associated with anorectal dysfunction, which include dyssynergia or inadequate defecatory propulsion. FDD are frequently encountered in clinical practice and may affect up to 33-50% of patients with chronic constipation. The etiology of FDD is unclear, however, it has been defined as an acquired, but subliminal behavioral disorder. Pathophysiologic mechanisms may include discoordination of rectoanal muscles, paradoxical contraction or insufficient relaxation of puborectalis and/or anal sphincter during defecation, and sluggish colonic transit. A combination of comprehensive clinical assessment, digital rectal examination and a battery of physiologic tests are needed to make an accurate diagnosis of FDD. Defecography may play a crucial role in the evaluation of FDD, especially when a balloon expulsion test (BET) and/or anorectal manometry (ARM) are equivocal or demonstrate contradictory results. In this review, we provide a thorough overview of the epidemiology, pathophysiology, diagnostic criteria, clinical and imaging evaluation, and treatment options for FDD, with an emphasis on available diagnostic imaging tools such as defecography and conventional fluoroscopic methods.

Effect of short-term cold temperature stress on development, survival and reproduction of Dysdercus koenigii (Hemiptera: Pyrrhocoridae).

Red cotton bug Dysdercus koenigii F. (Hemiptera: Pyrrhocoridae), is found destructive pest in various cotton growing areas. Under natural conditions insects are highly subjected to thermal stresses. In present work the developmental duration and survival rate of all immature stages, adult longevity and reproduction of D. koenigii by exposed to rapid changes in very low temperatures were studied. When 3 h short-stress of low temperatures (12-0 °C) was given to different stages of D. koenigii, the results revealed that survival rate of all stages were significantly reduced. Survival rate of female was significantly higher than male after exposed to cold temperature stress. Mating percentage, fecundity and hatching percentage were decreased significantly with the decrease of short-term cold temperature stress. Based on these results, we concluded that the developmental duration, survival rate and reproduction of D. koenigii significantly affected when they exposed to short term cold temperature stress.

Frontiers of cancer imaging and guided therapy using ultrasound, light, and microwaves.

This review describes emerging techniques within the last 5 years that employ ultrasound for detecting and staging malignancy, tracking metastasis, and guiding treatment. Ultrasound elastography quantifies soft tissue elastic properties that change as a tumor grows and proliferates. Hybrid imaging modalities that combine ultrasound with light or microwave energy provide novel contrast for mapping blood oxygen saturation, transport of particles through lymphatic vessels and nodes, and real-time feedback for guiding needle biopsies. Combining these methods with smart nanoparticles and contrast agents further promotes new paradigms for cancer imaging and therapy.

A multi-institution prospective observational study of small bowel obstruction: Clinical and computerized tomography predictors of which patients may require early surgery.

BACKGROUND: For patients with adhesive small bowel obstruction (ASBO), early surgery after a failed trial of nonoperative treatment can improve outcome. However, deciding which patients require early surgery is difficult, given the lack of specific clinical or radiographic signs. The study goals were to identify clinical and computed tomography (CT) predictors of which patients may need early surgery and to evaluate the utility of the common CT findings. METHODS: This was a multi-institution prospective observational study for patients who were admitted with ASBO. Patients were excluded if their SBO were not managed conservative initially; were within 30 days postoperatively; were caused by external hernias, small bowel tumor, or intussusception; and were related to Crohn's disease. Clinical and laboratory variables were collected prospectively. CT findings were interpreted by a blinded designated radiologist. To identify significant predictors, we performed a multivariable regression analysis. RESULTS: During 22 months, we enrolled 200 patients with ASBO. Patients' mean (SD) age was 60 (18) years; 50% were male. Fifty-two patients (26%) underwent surgery. Of those who underwent surgery, the median duration of nonoperative treatment was 1.5 days (interquartile range, 1-2.5 days). In the regression model, we identified no flatus (odds ratio [OR], 3.28; 95% confidence interval [CI], 1.51-7.12; p = 0.003), presence of free fluid on CT (OR, 2.59; 95% CI, 1.13-5.90; p = 0.023), and high-grade obstruction by CT (OR, 2.44; 95% CI, 1.10-5.43; p = 0.028) to be significant predictors for ASBO patients who may need early surgery. CONCLUSION: In this study, we prospectively derived one clinical and two CT predictors which ASBO patients may benefit from an early surgical intervention. However, a future study to validate these predictors is needed. LEVEL OF EVIDENCE: Therapeutic study, level III; prognostic study, level II.

MR imaging of benign and malignant biliary conditions.

MR imaging is a noninvasive, radiation-free imaging method for evaluation of the biliary system. Continued advancements in MR imaging system hardware and sequence design, coupled with novel gadolinium chelate agents, allow for a detailed evaluation of the bile ducts and surrounding soft tissues. New hepatocyte-specific contrast agents may hold utility in the anatomic and functional evaluation of bile duct injury. MR imaging is also the imaging method of choice for bile duct tumor diagnosis, staging, and presurgical planning. Familiarity with the proper methodology of MR image acquisition and interpretation is critical for optimized diagnostic assessment.