Role of intestinal ultrasound in ulcerative colitis: A systematic review

Table 1 Summary of studies evaluating intestinal ultrasound for diagnosis of inflammatory bowel disease/ulcerative colitis and differentiating inflammatory bowel disease mimics

Ref.	Study type	Number of patients	Equipment	Criteria for abnormal findings	Reference	Sensitivity	Specificity	PPV	NPV
Hollerbach et al[5]	Prospective	227 suspected IBD patients	5 MHz curved array probe	BWT > 4 mm, target sign, lumen < 4 mm, ascites, abscess, reduced compressibility, conglomerate tumor (any 2 of the above)	Colonoscopy, enteroclysis, enema, CT scan, surgery	76% (84% CD, 66% UC) (10%-20% in jejunum, duodenum, rectum)	95%	98%	58%
Astegiano et al[1]	Prospective	313 (abdominal pain and altered bowel habits ≥ 3 mo)	7.5-10 MHz linear probe and 3.5 MHz convex probe	BWT ≥ 7 mm, BWT between 5-6 needs follow-up	Radiology and endoscopy	74% (84% CD, 38% UC)	98%	92%	92%
Chavannes et al[72]	Cross-sectional, single centre	33 children with suspected IBD (11 UC)	3-12 MHz linear probe and 3-10 MHz convex probe	BWT > 1.9 mm cut-off for inflamed bowel	Colonoscopy	64%	76%	-	-
Rossaint et al[3]	Prospective	487 suspected IBD patients	7.5 MHz linear, 3.5 MHz convex	BWT > 4 mm	Endoscopy, small bowel enteroclysis, CT	85% Rectum: 14% Duodenum/jejunum: 29%	95%	98%	75%
Dell'Era et al[7]	Retrospective	113 suspected pediatric IBD patients	3.5-5 MHz curvilinear probe, 4-8 MHz microconvex probe	BWT, BWS, lymph nodes, i-fat	Ileo-colonoscopy	BWS: 78.3% i-fat: 65.2%; BWT > 3: 69.6%. All 3: 56.5%. Any of 3: 82.6%	BWS: 93.3. i-fat: 92.2%; BWT > 3: 96.7%. All 3: 100%; Any of 3: 86.7%	BWS: 75% i-fat: 68.2%; BWT > 3: 84.2%; All 3: 100%. Any of 3: 61.3%	BWS: 94.4% i-fat: 91.2%; BWT > 3: 92.6%; All 3: 90%. Any of 3: 95.1%
Ziech et al[8]	Prospective	28 children with suspected IBD	Linear probe 5-12 MHz	BWT, BWS, lymph nodes, Doppler of mesenteric arteries	Ileo-colonoscopy and endoscopy	55% (improved with combination of MRI 83%-87%)	100%	-	-
White et al[9]	Prospective	37 patients with low-risk GI symptoms, FCP < 150 µg/g, CRP < 10 g/d	5-8 MHz curvilinear probe, 18 MHz linear probe	BWT > 3 mm, increased CDS, loss of BWS, inflammatory fat, lymph nodes	NA	-	-	-	-
Jeffrey et al[10]	Retrospective	32 patients with focal GI lesions, 20 controls	5 MHz linear array transducer	≥ 4 blood vessels measuring 3 mm or more over 5 cm segment/extending into mesentery	Surgery, biopsy, endoscopy	-	-	-	-
Zhang et al[11]	Retrospective	13 IBD, 38 colon cancer	Curvilinear probe 2-5 MHZ (for CEUS, MI 0.07-0.10, dynamic range 50 dB), linear probe 3-9 MHz, SonoVue contrast	Increased BWT, loss of BWS, “comb-teeth like” vessels on color Doppler, disordered enhancement, heterogeneous enhancement	Histology for colon cancer, clinical/pathologic and endoscopic exams for IBD	Colon cancer BWS: 97.4%; Disordered enhancement: 94.7%. Heterogeneous enhancement: 78.9%	Colon cancer BWS: 69.2%; Disordered enhancement: 92.3%. Heterogeneous enhancement: 100%	-	-
Kapoor et al[12]	Retrospective, single centre	76 patients with chronic diarrhoea and abdominal pain	Convex probe: 3.5-8 MHz, linear probe: 8-14 MHz	Abnormal bowel wall stiffness (> 12 kPa) and abnormal inflammation (> 14 m/s/kHz); wall thickening (> 3 and > 4 for small and large bowel), stratification, node, fluid, fat, and fistula	Contrast enhanced CT, endoscopic and surgical biopsy	100%	99%	-	-

IBD: Inflammatory bowel disease; BWT: Bowel wall thickness; CD: Crohn’s disease; UC: Ulcerative colitis; CT: Computed tomography; IBS: Irritable bowel syndrome; PPV: Positive predictive value; NPV: Negative predictive value.