MDCT of small bowel tumours

Abstract

Primary benign and malignant neoplasm of the small bowel are rare. Malignant tumours often present late symptoms resulting in a poor prognosis. Early detection of small bowel neoplasms is desirable but challenging for both clinicians and radiologists. Conventional double contrast enteroclysis was the method of choice in small bowel imaging but is increasingly being replaced by cross-sectional imaging methods as computed tomography (CT) and magnetic resonance imaging (MRI). Multidetector CT (MDCT) produces high-resolution cross-sectional imaging of the abdomen and the small bowel. It allows multiplanar visualisation of small bowel tumours, demonstrates signs of small bowel obstruction as well as the mural and extramural extent of small bowel malignancies. This aids planning for surgical resection. In addition, liver metastases or peritoneal seeding can be detected with CT. The best visualisation of small bowel neoplasms is achieved with CT enteroclysis or enterography and this review discusses these techniques and MDCT characteristics of small bowel tumours.

Malignant Small Bowel Tumors: Diagnosis, Management and Prognosis

“…The lack of specific symptoms and clinical signs for small bowel malignancies classically delays the diagnosis and complications like active bleeding, intestinal obstruction or perforation can be the presenting patterns. 5,8 Thus, it is necessary not to disregard the suspicion of malignant small bowel tumors in clinical context, since prompt diagnosis and treatment may improve the prognosis of patients suffering from this condition. The small bowel has always been an organ difficult to access and for long the diagnosis of these tumors relied on indirect imaging procedures or surgery.…”

“…Computed tomography and magnetic resonance imaging techniques can be useful in detecting those lesions, particularly with the advent of high-resolution images. 8,36 Despite this, they cannot provide precise data about the intestinal mucosa and can miss some lesions, particularly if small and flat. Endoscopic methods such as upper endoscopy and colonoscopy can be appropriate if the lesion is located as close as the proximal duodenum or as far as the terminal ileum, but the rest of the small bowel cannot be accessed.…”

Malignant tumours of the small intestine: a review of histopathology, multidetector CT and MRI aspects

“…Central ulceration may be present in 10% of cases. Adenocarcinomas of the jejunum and ileum usually appear as an annular narrowing with abrupt concentric or irregular ''overhanging edge'' stenosis ( Figure 6) that could lead to partial or complete obstruction [17,22]. After intravenous contrast agent administration, moderate heterogeneous enhancement is usually seen [14].…”

“…Thereafter, depending on the indication, arterial and/or portal venous phase imaging [14,22] must be performed after intravenous administration of contrast agent (2 ml kg 21 at 3.5-4 ml s 21 ). Bolus tracking techniques with measurements performed in the abdominal aorta can be used to adapt the delay between contrast agent administration and scan initiation to the cardiac output of the individual patient; however, delays of 35-40 s and 60-65 s are often appropriate for arterial and portal-venous phase acquisitions, respectively.…”

“…The availability of faster scanners permits the routine use of submillimetre collimations (16 6 0.75 mm and 64 6 0.75 mm) that can generate almost isotropic three-dimensional (3D) data sets from multiphasic acquisitions. Evaluation of MDCT data sets should be performed on off-line consoles dedicated for 3D reconstructions (the availability of maximum intensity projection and multiplanar reformatted images facilitates the evaluation of SB lumen and its relationship with adjacent vessels) [14,22].…”