A prospective study assessing the efficacy of abdominal computed tomography scan without bowel preparation in diagnosing intestinal wall and luminal lesions in patients presenting to the emergency room with abdominal complaints

Table 1 Presenting symptoms.

Symptom	Number of patients
Abdominal pain	15
Diarrhea	4
Constipation	4
Vomiting	3
Weight loss	2
Anemia	4
Change in bowel habits	1
Rectal bleeding	3

Table 2 Diagnoses made by ER physicians and CT vs colonoscopy findings and histology results.

Patient number	ER physician’s clinical diagnoses (prior to the CT scan)	CT findings and suggested diagnoses	Colonoscopy findings	Histology (when available)
1	Bowel obstruction	Ascending colon tumor	Ascending colon tumor	Well-differentiated adenocarcinoma
2	Inflammatory bowel disease	Inflammatory bowel disease of terminal ileum	Inflammation, ulceration and pseudopolyps by the ileo-cecal valve	Active chronic inflammation
3	Acute appendicitis or acute diverticulitis	Descending colon tumor	Obstructing descending colon tumor	Well-differentiated adenocarcinoma
4	Colonic tumor	Transverse colon tumor	Mid-transverse colon tumor	Moderately to poorly differentiated adenocarcinoma
5	Acute diverticulitis	Sigmoid colon wall thickening and polyp	Erythematous sigmoid colon mucosa and a sessile polyp	Hyperplastic mucosal glands
6	Acute diverticulitis	Right colon wall thickening from cecum to hepatic flexure	Right colon congested and erythematous mucosa with mucopurulent exudate	Acute inflammation with ulceration and fibrinopurulent exudates
7	Acute appendicitis	Ascending colon tumor	Ascending colon fungating tumor	Acute and chronic ischemic changes. No neoplastic process
8	Colonic tumor	Cecal tumor with liver metastasis	Cecal tumor	Moderately differentiated adenocarcinoma
9	Gastric or colonic carcinoma	Cecal tumor	Cecal tumor	Ulcerated moderately to poorly differentiated adenocarcinoma
10	Colitis	Diffuse colon wall thickening	Normal
11	Colonic tumor	Transverse colon tumor	20-mm large base cecal polyp with villous appearance	Tubulo-villous adenoma with low- grade dysplasia
12	Colonic tumor	Sigmoid colon tumor	Normal
13	Pelvic inflammatory disease or inflammatory bowel disease	Diffuse bowel wall thickening, suspected Crohn’s disease	Normal
14	Acute appendicitis	Cecal and ascending colon wall thickening	Normal
15	Acute diverticulitis or renal colic	Descending colon tumor	Cecal polyp	Tubular adenoma with focal high-grade dysplasia
16	Acute appendicitis or acute cholecystitis	Cecal tumor, hepatosplenomegaly	Diffuse angiodysplasia
17	Inflammatory bowel disease or infectious colitis	Terminal ileum wall thickening, suspected Crohn’s disease	Normal
18	Inflammatory bowel disease	Inflammatory changes in the ileo-cecal valve area	Normal
19	Acute pancreatitis or acute cholecystitis	Terminal ileum wall thickening, hepatosplenomegaly, right ovarian cyst	Normal
20	Bowel obstruction	Ascending to mid-transverse colon wall thickening	2-mm colonic polyp	Inflamed sessile adenomatous polyp

Table 3 True-and false-positive frequency, positive predictive value (with 95%CI), for NPCT scan, according to specific CT diagnosis.

CT diagnoses	Total number	True positive	False positive	Positive predictive value (95%CI)
Colonic tumor	10	6	4	60% (29-86)
Inflammatory bowel	9	2	7	22% (4-56)
disease
Colonic polyp	1	1	0	100% (5-100)
Total number	20	9	11	45% (25-67)

Table 4 True-and false-positive frequency, positive predictive value for NPCT scan, including patients with delayed colonoscopy.

CT diagnoses	Total number	True positive	False positive	Positive predictive value (95%CI)
Colonic tumor	11	7	4	63% (3-487)
Inflammatory bowel	13	2	11	15% (3-42)
disease
Colonic polyp	1	0		100% (5-100)
Total number	25	10	15	40% (2-260)