The role of intestinal ultrasound in diagnostics of bowel diseases

Focused ultrasound enables selective actuation and Newton-level force output of untethered soft robots

Untethered miniature soft robots have significant application potentials in biomedical and industrial fields due to their space accessibility and safe human interaction. However, the lack of selective and forceful actuation is still challenging in revolutionizing and unleashing their versatility. Here, we propose a focused ultrasound-controlled phase transition strategy for achieving millimeter-level spatially selective actuation and Newton-level force of soft robots, which harnesses ultrasound-induced heating to trigger the phase transition inside the robot, enabling powerful actuation through inflation. The millimeter-level spatial resolution empowers single robot to perform multiple tasks according to specific requirements. As a concept-of-demonstration, we designed soft robot for liquid cargo delivery and biopsy robot for tissue acquisition and patching. Additionally, an autonomous control system is integrated with ultrasound imaging to enable automatic acoustic field alignment and control. The proposed method advances the spatiotemporal response capability of untethered miniature soft robots, holding promise for broadening their versatility and adaptability.

Diagnostic Accuracy of Ultrasonography by Emergency Medicine Resident in Detecting Intestinal Obstruction; a Pilot Study

Introduction

There are many ambiguities regarding the application of ultrasound in detection of intestinal obstruction. This study aimed to evaluate the diagnostic accuracy of ultrasound in diagnosis of intestinal obstruction.

Methods

This cross-sectional study was performed on patients with symptoms and signs of bowel obstruction between November 2019 and July 2020 in Shohadaye-Tajrish and Imam Hossein General Hospitals, Tehran, Iran. After a brief explanation and getting verbal consent, the patients underwent ultrasound examination in the emergency department by the emergency medicine resident. The results of ultrasound were compared with the surgical findings as the gold standard.

Results

24 patients with the mean age of 57.50±18.26 (range: 28 - 81) years were studied (58.3% male). Ultrasonography findings revealed the lumen diameter ≥ 2.5 cm in 21 (87.5%) cases, wall thickness ≥ 3 mm in 3 (12.5%) cases and inter-loop free fluid in 3 (12.5%) cases. Sensitivity, positive predictive value, and accuracy of ultrasound in detection of intestinal obstruction were found to be 85.00% (95%CI: 61.13 - 96.03), 80.95% (95%CI: 57.42 - 93.71), and 70.83% (95%CI: 48.91 - 87.38), respectively.

Conclusion

It seems that point-of-care ultrasound has good sensitivity and accuracy in detection of intestinal obstruction when performed in the emergency department by a trained emergency medicine resident.

Consistency of Trans-Abdominal and Water-Immersion Ultrasound Images of Diseased Intestinal Segments in Crohn's Disease

The aim of this study is to clarify whether trans-abdominal ultrasound (TAUS) can reflect actual intestinal conditions in Crohn’s disease (CD) as effectively as water-immersion ultrasound (WIUS) does. This retrospective study enrolled 29 CD patients with 113 intestinal lesions. Five ultrasound (US) parameters (distinct presence/indistinct presence/disappearance of wall stratification in the submucosal and mucosal layers; thickened submucosal layer; irregular mucosal surface; increased fat wrapping around the bowel wall; and fistula signs) that may indicate different states in CD were determined by TAUS and WIUS for the same lesion. Using WIUS as a reference standard, the sensitivity, specificity, and accuracy of TAUS were calculated. The degree of agreement between TAUS and WIUS was evaluated by the kappa coefficient. All US parameters of TAUS had an accuracy >70% (72.6–92.7%). The highest efficacy of TAUS was obtained for fistula signs (sensitivity, specificity, and accuracy values were 63.6%, 96.0%, and 92.7%, respectively). All US parameters between TAUS and WIUS had a definitive (p ≤ 0.001) and moderate-to-substantial consistency (kappa value = 0.446–0.615). The images of TAUS showed substantial similarity to those of WIUS, suggesting that TAUS may function as a substitute to evaluate the actual intestinal conditions of CD.