Use of shear wave imaging with intestinal ultrasonography in patients with chronic diarrhea.

OBJECTIVE: A retrospective study was designed to determine the role of shear wave elastography (SWE) and intestinal ultrasonography to differentiate between inflammatory and fibrotic bowel strictures by determining Young's modulus (E) and shear wave dispersion (SWD) and to compare its role with contrast-enhanced computed tomography (CECT) in patients with chronic diarrhea and pain abdomen. METHODS: Seventy-six patients who had increased small bowel thickness (SBWT) >3 mm, and large bowel wall thickness (LBWT) >4 mm on intestinal ultrasonography (IUS) were evaluated in a two-step manner. The first step involved classifying patients with increased SBWT >3 mm and LBWT >4 mm by use of SWE and dispersion into three groups that is group I (fibrotic), group II (inflammatory) thickening, and group III (mixed-fibrosis and inflammatory) wall thickening. In the second step, etiological classification was done using six gray scale features of IUS that is length and degree of bowel thickening, presence of bowel stratification, Limberg grade of vascularity, status of mesenteric fat, juxta bowel status-nodes, fluid, and fistula formation to reach to a definitive diagnosis. These findings were compared with findings on CECT. Twenty-three patients had diagnosis confirmed by biopsy while 18 underwent surgery with histologic confirmation of operative findings. The sensitivity, specificity and AUROC for both modalities were compared. RESULTS: Group I that is fibrotic group had 33 patients with fibrotic strictures of which fibrotic Crohn's disease (CD)and tuberculosis of the bowel were the dominant types followed by neoplastic and infective causes. In Group II that is inflammatory there were 32 patients with predominantly infective ileo-colitis, and ulcerative colitis patients while 11 patients were present in group III that is (mixed fibrotic and inflammatory) type of bowel wall thickening and were patients of inflammatory CD, infective ileo-colitis. The presence of length of bowel involvement, Limberg grade, mesenteric fat proliferation, and SBWT>9 mm were the statistically significant parameters on IUS which helped to reach to final diagnosis. The sensitivity and specificity of combined SWE with SWD and IUS were 100% and 99% while that of CECT was 78% and 96% respectively with AUROC of 100% and 64%. CONCLUSION: SWI combined with IUS in a two-step manner is an accurate way to evaluate patients with chronic diarrhea who have increased SBWT and is not only able to differentiate inflammatory from fibrotic bowel wall thickening but also helps to form an etiological diagnosis.

Adhesions Detection and Staging Classification for Preoperative Assessment of Difficult Laparoscopic Cholecystectomies: A Prospective Case-Control Study.

Background: Laparoscopic cholecystectomy (LC) is the treatment of choice for cholelithiasis; however, there are procedural difficulties in determining preoperative detection of a difficult LC. The current methods using clinical and sonographic variables to identify difficult LCs have limitations to identify gallbladder adhesions which form the most common cause. We present a new method of evaluation using acoustic radiation force impulse (ARFI)-based virtual touch imaging (VTI) for the detection and classification of these patients. Methods: Fifty consecutive patients of cholelithiasis were evaluated preoperatively using conventional scoring system (CSS) and by new adhesion detection and staging (ADS) system, and patients were classified into three classes (I-III) with class I being easy, II and III being moderate-to-high difficulty LCs. Peroperative classification was done based on the difficulty level during surgery after visualization of gallbladder adhesions. The sensitivity, specificity, and area under the curves (AUCs) of both systems were compared. Results: Out of 50 patients, 72% and 54% of patients were in class I by CSS and ADS classification, while 28% and 46% were in class II and III, respectively, and were labeled as difficult LC cases; differences being two classifications were statistically significant (P = 0.02). Sensitivity, specificity, negative predictive value, and accuracy for ADS were 91%, 100%, 93.1%, and 96.0%, and for CSS, 60.9%, 100%, 75%, and 82% with AUCs of 1.0 and 0.63, respectively. Conclusion: ARFI-based VTI accurately detects gallbladder adhesions and can determine the difficult cases of LCs preoperatively using ADS classification and shows higher accuracy than CSS classification, which results in lower operative time and risk of complications.