Utility of tele-guidance for point-of-care ultrasound: a single center prospective diagnostic study.

BACKGROUND: Point-of-care-ultrasound (POCUS) improves diagnostic accuracy and expedites lifesaving procedures. Remote areas disproportionately underuse ultrasound (US) due to a dearth of US trained professionals, imaging tools, and lack of quality assurance. Handheld US probes have been approved for diagnostic imaging but there have been limited studies examining their tele-guidance features. This study investigates whether physician tele-guidance improved ultrasound image acquisition by untrained scanners. METHODS: To determine the effectiveness of tele-guidance for ultrasound image acquisition, 30 participants (15 in each study arm: experimental and control) with no ultrasound or medical experience gathered images of the heart, right kidney, and gallbladder of a standardized patient using a handheld ultrasound probe (Butterfly iQ +). All participants watched a standardized ultrasound tutorial video and were randomized into the control or experimental group. A physician assisted the experimental group using ultrasound probe's tele-guidance feature while the control group received no assistance. Time to image acquisition was recorded for both groups, and the images were graded by 3 blinded radiologists using the RACE tool to determine image and diagnostic quality. RESULTS: There was evidence that mean imaging time was greater in the control group for the heart, right kidney, and gallbladder (p < 0.0001, all; Cohen's DL: 2.0, 1.7, 3.0, respectively). Similarly, there was evidence that the predicted mean image quality for the heart, right kidney, and gallbladder was higher for the experimental group compared to the control group (3.46 versus 1.86, 4.49 versus 1.58, and 3.93 versus 1.5, respectively; p < 0.0001, all). There was also evidence that the diagnostic quality of images had a statistically higher predicted probability of meaningful interpretation for the experimental group for pericardial fluid, intraperitoneal fluid, and acute cholecystitis (p = 0.003, p < 0.0001, p < 0.0001, respectively). CONCLUSIONS: Tele-guidance improves time to image acquisition and clinical applicability of ultrasound images obtained by untrained scanners.

Initial clinical evaluation of stationary digital chest tomosynthesis in adult patients with cystic fibrosis.

OBJECTIVE: The imaging evaluation of cystic fibrosis currently relies on chest radiography or computed tomography. Recently, digital chest tomosynthesis has been proposed as an alternative. We have developed a stationary digital chest tomosynthesis (s-DCT) system based on a carbon nanotube (CNT) linear x-ray source array. This system enables tomographic imaging without movement of the x-ray tube and allows for physiological gating. The goal of this study was to evaluate the feasibility of clinical CF imaging with the s-DCT system. MATERIALS AND METHODS: CF patients undergoing clinically indicated chest radiography were recruited for the study and imaged on the s-DCT system. Three board-certified radiologists reviewed both the CXR and s-DCT images for image quality relevant to CF. CF disease severity was assessed by Brasfield score on CXR and chest tomosynthesis score on s-DCT. Disease severity measures were also evaluated against subject pulmonary function tests. RESULTS: Fourteen patients underwent s-DCT imaging within 72 h of their chest radiograph imaging. Readers scored the visualization of proximal bronchi, small airways and vascular pattern higher on s-DCT than CXR. Correlation between the averaged Brasfield score and averaged tomosynthesis disease severity score for CF was -0.73, p = 0.0033. The CF disease severity score system for tomosynthesis had high correlation with FEV1 (r = -0.685) and FEF 25-75% (r = -0.719) as well as good correlation with FVC (r = -0.582). CONCLUSION: We demonstrate the potential of CNT x-ray-based s-DCT for use in the evaluation of cystic fibrosis disease status in the first clinical study of s-DCT. KEY POINTS: • Carbon nanotube-based linear array x-ray tomosynthesis systems have the potential to provide diagnostically relevant information for patients with cystic fibrosis without the need for a moving gantry. • Despite the short angular span in this prototype system, lung features such as the proximal bronchi, small airways and pulmonary vasculature have improved visualization on s-DCT compared with CXR. Further improvements are anticipated with longer linear x-ray array tubes. • Evaluation of disease severity in CF patients is possible with s-DCT, yielding improved visualization of important lung features and high correlation with pulmonary function tests at a relatively low dose.

Comparative Analysis of Cone-Beam CT Angiogram and Conventional CT Angiogram for Prostatic Artery Identification Prior to Embolization.

Pre-prostatic artery embolization (PAE) cone-beam computed tomography (CT) angiograms (n = 31; mean age: 62.4 ± 9.75 years) and conventional CT angiograms (n = 32; mean age: 62.5 ± 7.2 years) were retrospectively compared. Mean signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), radiation exposure, and prostatic artery (PA) identification scores (0-4) for cone-beam CT angiogram and conventional CT angiogram were 33.19 (± 14.31) and 18.13 (± 5.38) (P < .01); 27.42 (± 13.39) and 14.78 (± 4.92) (P < .01); 14.57 mSv (±2.5) and 19.25 mSv (±3.7) (P < .01); 3.36 (± 0.89) and 3.16 (± 0.95) (P = .08), respectively. Pre-PAE cone-beam CT angiogram allows for PA identification with improved SNR and CNR and less radiation dose compared to conventional CT angiogram.