Automated Detection, Segmentation, and Classification of Pleural Effusion From Computed Tomography Scans Using Machine Learning.

OBJECTIVE: This study trained and evaluated algorithms to detect, segment, and classify simple and complex pleural effusions on computed tomography (CT) scans. MATERIALS AND METHODS: For detection and segmentation, we randomly selected 160 chest CT scans out of all consecutive patients (January 2016-January 2021, n = 2659) with reported pleural effusion. Effusions were manually segmented and a negative cohort of chest CTs from 160 patients without effusions was added. A deep convolutional neural network (nnU-Net) was trained and cross-validated (n = 224; 70%) for segmentation and tested on a separate subset (n = 96; 30%) with the same distribution of reported pleural complexity features as in the training cohort (eg, hyperdense fluid, gas, pleural thickening and loculation). On a separate consecutive cohort with a high prevalence of pleural complexity features (n = 335), a random forest model was implemented for classification of segmented effusions with Hounsfield unit thresholds, density distribution, and radiomics-based features as input. As performance measures, sensitivity, specificity, and area under the curves (AUCs) for detection/classifier evaluation (per-case level) and Dice coefficient and volume analysis for the segmentation task were used. RESULTS: Sensitivity and specificity for detection of effusion were excellent at 0.99 and 0.98, respectively (n = 96; AUC, 0.996, test data). Segmentation was robust (median Dice, 0.89; median absolute volume difference, 13 mL), irrespective of size, complexity, or contrast phase. The sensitivity, specificity, and AUC for classification in simple versus complex effusions were 0.67, 0.75, and 0.77, respectively. CONCLUSION: Using a dataset with different degrees of complexity, a robust model was developed for the detection, segmentation, and classification of effusion subtypes. The algorithms are openly available at https://github.com/usb-radiology/pleuraleffusion.git.

Antibiotic prophylaxis in transurethral resection of bladder tumours: study protocol for a systematic review and meta-analysis.

BACKGROUND: The necessity of antibiotic prophylaxis for postoperative urinary tract infections (UTIs) after transurethral resection of bladder tumours is controversial. This potentially leads to the overuse of antibiotic prophylaxis and rising antimicrobial resistance rates. The objective of this systematic review and meta-analysis is to compare the impact of different antimicrobial prophylaxis schemes versus placebo on the prevention of postoperative UTI and asymptomatic bacteriuria. METHODS: We designed and registered a study protocol for a systematic review and meta-analysis of randomized controlled trials and non-randomized (e.g. cohort, case-control) studies examining any form of antibiotic prophylaxis in patients with transurethral resection of bladder tumours. Literature searches will be conducted in several electronic databases (from inception onwards), including MEDLINE (Ovid), EMBASE (Ovid), and the Cochrane Central Register of Controlled Trials (CENTRAL). Grey literature will be identified through searching conference abstracts. The primary outcome will be postoperative urinary tract infections. The secondary outcome will be asymptomatic bacteriuria. Two reviewers will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The study methodological quality (or bias) will be appraised using appropriate tools (e.g. Risk of Bias 2.0 tool and Newcastle-Ottawa Scale). If feasible, we will conduct random-effects meta-analysis of outcome data. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g. study design, publication year, the setting of the study, and antibiotics regimen). We will also search, identify, and discuss potential risk factors for urinary tract infections following transurethral resection of bladder tumours. This may serve as basis for a scoping review. DISCUSSION: In times of rising antimicrobial resistance rates, sound evidence on the necessity of antibiotic prophylaxis is essential for implementation into guideline recommendations and for decision-making in clinical practice. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42019131733.

Overuse of antimicrobial prophylaxis in low-risk patients undergoing transurethral resection of the prostate.

OBJECTIVE: To evaluate the current antimicrobial prophylaxis practices for low-risk patients undergoing transurethral resection of the prostate (TURP) or photoselective vaporisation of the prostate (PVP) in comparison with the antimicrobial prophylaxis recommendations of the European Association of Urology (EAU), which have been shown to effectively reduce infectious complications and antimicrobial resistance rates. METHODS: In May 2017, we sent an anonymous online -survey to board-certified urologists in Germany, Austria and Switzerland, by use of the database directory of the respective urology associations. Besides demographical questions, urologists were asked about their sources of information on antimicrobial prophylaxis prescription and their prescribing patterns before, during and after surgery in patients without an indwelling catheter or significant bacteriuria undergoing TURP or PVP. RESULTS: Overall, 374 of 5825 urologists responded, of whom 76% (286/374) performed TURP and 16% (60/374) PVP. For TURP and PVP, respectively: (i) 42% (119/286) and 33% (20/60) reported routine use of preoperative antimicrobial prophylaxis, which does not conform to guideline recommendations; (ii) 43% (124/286) and 52% (31/60) reported prescribing non-recommended perioperative antimicrobial prophylaxis regimens; and (iii) 60% (172/286) and 65% (39/60) routinely extended antimicrobial prophylaxis after surgery for up to one week. In summary, of the urologists who responded to the questionnaire, 74% (211/286) reported nonadherence to guidelines on antimicrobial prophylaxis for TURP. CONCLUSION: A low adherence to guidelines for low-risk patients undergoing TURP or PVP was reported. Given these preliminary data, there is an urgent need to monitor adherence to antimicrobial prophylaxis guidelines in urology to reduce antimicrobial resistance rates.

Interleukin-6 Delays Gastric Emptying in Humans with Direct Effects on Glycemic Control.

Gastric emptying is a critical regulator of postprandial glucose and delayed gastric emptying is an important mechanism of improved glycemic control achieved by short-acting glucagon-like peptide-1 (GLP-1) analogs in clinical practice. Here we report on a novel regulatory mechanism of gastric emptying in humans. We show that increasing interleukin (IL)-6 concentrations delays gastric emptying leading to reduced postprandial glycemia. IL-6 furthermore reduces insulin secretion in a GLP-1-dependent manner while effects on gastric emptying are GLP-1 independent. Inhibitory effects of IL-6 on gastric emptying were confirmed following exercise-induced increases in IL-6. Importantly, gastric- and insulin-reducing effects were maintained in individuals with type 2 diabetes. These data have clinical implications with respect to the use of IL-6 inhibition in autoimmune/inflammatory disease, and identify a novel target that could be exploited pharmacologically to delay gastric emptying and spare insulin, which may be beneficial for the beta cell in type 2 diabetes.

Iron homeostasis in inflammation: a single centre prospective observational study in medical inpatients.

AIMS OF THE STUDY: We aimed to assess a potential association of iron status with mortality and morbidity of inpatients with systemic inflammation. METHODS: This was a single centre prospective observational study. From April 2014 to October 2014, all consecutive medical inpatients aged >=18 years with a C-reactive protein value >5 mg/l on hospital admission were eligible for the study. We excluded pregnant women and patients with terminal renal insufficiency or past allogeneic stem cell transplantation. For all patients, a complete set of serum iron parameters was obtained on hospital admission. In the final analysis, the in-hospital all-cause mortality and several morbidity measures (length of stay, number of secondary diagnoses and Charlson Comorbidity Index) were compared between four distinct iron status groups: patients having iron deficiency anaemia, iron deficiency without anaemia, anaemia without iron deficiency, and normal iron status. Iron deficiency was quantifies as the serum transferrin receptor / ferritin index, with a cut-off level of 1.5. RESULTS: A total of 438 patients were included in the final analysis. Patients with iron deficiency had a higher in-hospital mortality than patients with iron deficiency anaemia, anaemia without iron deficiency, or normal iron status (6% vs 1%, 5%, and 1%, respectively; p = 0.042). Patients with iron deficiency anaemia had a higher number of secondary diagnoses (mean 8.4; standard deviation 4.2) and a higher Charlson Comorbidity Index (mean 1.8; standard deviation 1.9) than patients with iron deficiency, anaemia without iron deficiency, or normal iron status (p <0.001 and p <0.001, respectively). The median length of stay did not differ significantly between the iron status groups (p = 0.080). CONCLUSIONS: In our study population, iron status was significantly associated with mortality and morbidity. Further studies are required to assess the pathophysiological and clinical effects of an altered iron metabolism and iron substitution therapies in inflammation.