Vesicoureteral reflux by contrast ultrasound, comparison with voiding and retrograde urethrocystography: A prospective accuracy study.

INTRODUCTION: Diagnosis of vesicoureteral reflux (VUR) plays an important role in the management and follow-up of children presenting with urinary tract infection. This study compared voiding uronosography (VUS) as a diagnostic method for the diagnosis of VUR with the "gold standard", voiding or micturating cystourethrography (MCU). The objective of the study is not only to compare the effectiveness of both methods, but also to assess the feasibility of implementing VUS technically and economically in a large tertiary radiology center in South America. MATERIALS AND METHOD: This was a prospective accuracy study that include 41 patients (a total of 85 ureteral units) aged between 1 month and 16 years. VUS was performed in an alternative form as regular MCU, by injecting microbubble contrast solution (SonoVue©) into the bladder through an intermittent catheter and evaluating the presence of reflux with ultrasound. MCU was always performed immediately after VUS. One pediatric radiologist evaluated all VUS exams, while a second independent pediatric radiologist evaluated all MCU exams, with both blinded to each other's assessments. RESULTS: Comparing VUS with MCU in the diagnosis of VUR, we observed a sensitivity of 92.3 % (95 % CI 74.9-99.1 %), specificity of 98.3 % (95 % CI 90.9-100 %), positive predictive value of 96.0 % (95 % CI 79.6-99.9 %), negative predictive value of 96.7 % (95 % CI 88.5-99.6 %) and a Kappa of 0.916 (0.822-1.000). When comparing the VUR grading between VUS and MCU the agreement between the two methods was high with a Kendall's Tau-b > 0.9. VUS failed to diagnose two grade 1 VUR reflux cases in teenagers while diagnosing one grade 4 VUR in a very dilated kidney-ureter unit, which was missed on MCU. VUS and MCU had similar costs when considering the price of the ultrasound contrast agent. DISCUSSION: VUS is a reliable alternative method to MCU for the diagnosis of VUR with the advantages of not exposing the child to ionizing radiation and potentially being more accessible due to the greater availability of ultrasound equipment. Limitations to this study include the usage of a single ultrasound equipment, which limits its generalizability and not evaluating the interobserver variability. CONCLUSION: Consideration should be given to implementing VUS for the diagnosis of VUR, particularly in centers without fluoroscopy equipment available, since the exam's performance and cost are comparable to those of the MCU.

Automated Computed Tomography Lung Densitometry in Bronchiectasis Patients

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Development and clinical application of a deep learning model to identify acute infarct on magnetic resonance imaging.

Stroke is a leading cause of death and disability. The ability to quickly identify the presence of acute infarct and quantify the volume on magnetic resonance imaging (MRI) has important treatment implications. We developed a machine learning model that used the apparent diffusion coefficient and diffusion weighted imaging series. It was trained on 6,657 MRI studies from Massachusetts General Hospital (MGH; Boston, USA). All studies were labelled positive or negative for infarct (classification annotation) with 377 having the region of interest outlined (segmentation annotation). The different annotation types facilitated training on more studies while not requiring the extensive time to manually segment every study. We initially validated the model on studies sequestered from the training set. We then tested the model on studies from three clinical scenarios: consecutive stroke team activations for 6-months at MGH, consecutive stroke team activations for 6-months at a hospital that did not provide training data (Brigham and Women's Hospital [BWH]; Boston, USA), and an international site (Diagnósticos da América SA [DASA]; Brazil). The model results were compared to radiologist ground truth interpretations. The model performed better when trained on classification and segmentation annotations (area under the receiver operating curve [AUROC] 0.995 [95% CI 0.992-0.998] and median Dice coefficient for segmentation overlap of 0.797 [IQR 0.642-0.861]) compared to segmentation annotations alone (AUROC 0.982 [95% CI 0.972-0.990] and Dice coefficient 0.776 [IQR 0.584-0.857]). The model accurately identified infarcts for MGH stroke team activations (AUROC 0.964 [95% CI 0.943-0.982], 381 studies), BWH stroke team activations (AUROC 0.981 [95% CI 0.966-0.993], 247 studies), and at DASA (AUROC 0.998 [95% CI 0.993-1.000], 171 studies). The model accurately segmented infarcts with Pearson correlation comparing model output and ground truth volumes between 0.968 and 0.986 for the three scenarios. Acute infarct can be accurately detected and segmented on MRI in real-world clinical scenarios using a machine learning model.

Efficacy of hemostatic powders in upper gastrointestinal bleeding: A systematic review and meta-analysis.

BACKGROUND: There is limited evidence on the efficacy of hemostatic powders in the management of upper gastrointestinal bleeding. AIMS: Provide a pooled estimate of the efficacy and safety profile of hemostatic powders in digestive endoscopy. METHODS: A computerized bibliographic search on the main databases was performed through December 2018. Pooled effects were calculated using a random-effects model. The primary outcome was immediate hemostasis rate. Secondary outcomes were rebleeding rate (either at 7 and 30 days), bleeding-related mortality, and all-cause mortality rate. RESULTS: A total of 24 studies, of which three were randomized-controlled trials, with 1063 patients were included in the meta-analysis. Immediate hemostasis was achieved in 95.3% (93.3%-97.3%) of patients, with no difference based on treatment strategy, hemostatic agent used, bleeding etiology. Success rate was slightly lower in spurting bleeding (91.9%). Hemostatic powders showed similar efficacy as compared to conventional endoscopic therapy (odds ratio: 0.84, 0.06-11.47; p = 0.9). Thirty-day rebleeding rate was 16.9% (9.8%-24%) with no difference in comparison to other endoscopic treatments (odds ratio 1.59, 0.35-7.21; p = 0.55). All-cause and bleeding-related mortality rates were 7.6% (4%-10.8%) and 1.4% (0.5%-2.4%), respectively. CONCLUSION: Novel hemostatic powders represent a user-friendly and effective tool in the management of upper gastrointestinal bleeding.