Obscure gastrointestinal bleeding: diagnostic performance of 64-section multiphase CT enterography and CT angiography compared with capsule endoscopy

Abstract

Objective: To compare the diagnostic capabilities between capsule endoscopy (CE) and multislice CT (MSCT) enterography in combination with MSCT angiography for assessment of obscure gastrointestinal bleeding (OGIB).

Methods: A total of 127 patients with OGIB were looked at in this study. 82 patients (aged 42.7 ± 19.1 years; 34 males) were assigned to receive MSCT diagnosis and 67 patients to (aged 53.9 ± 16.2 years; 28 males) receive CE diagnosis. Among them, 22 patients (aged 54.1 ± 19.1 years; 12 males) received both examinations. Oral isotonic mannitol and intramuscular injection of anisodamine were performed; non-ionic contrast (iopromide, 370 mg I ml(-1)) was intravenously administered; and then multiphase scanning was conducted at arterial, small intestinal and portal venous phases in MSCT. The results were compared with findings of reference standards including double balloon enteroscopy, digital subtraction angiography, intraoperative pathological examination and/or clinical diagnosis.

Results: Administration of anisodamine markedly increased the satisfaction rate of bowel filling (94.67% vs 28.57%; p < 0.001) but not the diagnostic yield (p = 0.293) of MSCT. Compared with MSCT, CE showed an improved overall diagnostic yield (68.66% vs 47.56%; p = 0.010), which was also observed in overt bleeding patients (i.e. patients with continued passage of visible blood) (76.19% vs 51.02%; p = 0.013) and in patients aged younger than 40 years of age (85% vs 51.28%; p = 0.024). However, CE had similar positive rates to MSCT (p > 0.05). Among the 22 cases in whom both examinations were conducted, CE showed no significantly different diagnostic capability compared with MSCT (p = 0.4597).

Conclusion: Both CE and MSCT are safe and effective diagnostic methods for OGIB.

Advances in knowledge: CE is preferred for overt bleeding or patients aged younger than 40 years. The combined use of CE and MSCT is recommended in OGIB diagnosis.

Figure 1.

Diagnostic images of a 53-year-old male with gastrointestinal stromal tumour, which was revealed in multislice CT as well as double balloon enteroscopy (DBE), intraoperative pathological examination and histopathological examination. (a, b) The multislice CT enterography images showed highly enhanced small bowel and hypervascular tumour (arrows). (c, d) The DBE images clearly revealed the submucosal tumour and ulcer on the surface (arrows). (e) The excised tumour (arrow). (f) Tumour cells demonstrated by haematoxylin and eosin staining.

Figure 2.

Diagnostic images of a 75-year-old female with arteriovenous malformation, which was revealed by multislice CT (MSCT) as well as digital subtraction angiography (DSA), intraoperative pathological examination and histopathological examination. The patient had anaemia for 2 years and showed interstitial haemorrhage of the digestive tract for 2 months. Gastroduodenoscopic and colonoscopic studies did not reveal any possible cause of chronic bleeding. (a, b) The MSCT images, which were processed using volume-rendered technique (a) and the maximum intensity projection (b) showed the enlarged artery and early opacified veins during arterial phase scanning of hepatic flexure of the colon (arrows). (c) The DSA image revealed that the mesenteric artery appeared tortuous and veins were visible too early (arrow). (d) After surgical resection, shrinkage of the malformed vascular (marked by suture) at the mucosal surface was observed. (e) Arteriovenous malformation was demonstrated by haematoxylin and eosin staining with varicose arteries and veins and no capillary vessel in the intervals.

Figure 3.

Diagnostic images of a 72-year-old female with hookworm infection, which was revealed by capsule endoscopy (CE) as well as clinical diagnosis and treatment. The patient visited the hospital because of palpitation for 2 months. The patient's blood showed anaemia (haemoglobin, 57 g l⁻¹). No clear aetiology of gastrointestinal bleeding was found by gastroduodenoscopy and colonoscopy. The images of CE displayed many hookworms in the enteric cavity, intestinal mucosal hyperaemia of local small intestine and a small amount of pale bloody fluid. The patient was also diagnosed as ancylostomiasis in clinical. After receiving 400 mg of albendazole treatment for 3 days in combination with iron supplement and other supportive treatments, the symptoms of the patient were alleviated.

Figure 4.

Diagnostic performance of capsule endoscopy (CE) and multislice CT (MSCT) examinations investigated by receiver operator characteristic (ROC) curve analysis.