Ultrasound Technical Aspects Ultrasound is a widely accessible, noninvasive imaging method that has many advantages over other imaging methods. It is portable and relatively inexpensive with high spatial and temporal resolution. It does not involve ionizing radiation and can be…
Surgical procedures performed on the bowel are innumerable, and their detailed discussion is beyond the scope of this chapter. To understand the related imaging, it is important to be familiar with the postoperative anatomy. Our purpose in this chapter is…
Etiology The causes of the development of colorectal carcinoma and its precursor lesion, the colonic adenoma, are multifactorial and include both genetic predisposition and environmental insults. Risk factors for colorectal carcinoma include familial polyposis syndrome, ulcerative colitis, family history of…
Etiology Vascular lesions of the colon are an important medical problem and have now been recognized as a significant cause of gastrointestinal bleeding. They can be solitary or multifocal, benign or malignant, or associated with a syndrome or systemic disorder.…
Etiology Colonic inflammation may be caused by numerous processes and is typically thought of as colitis. Some inflammatory conditions of the colon such as diverticulitis and epiploic appendagitis also represent inflammatory lesions of the colon and, on occasion, may be…
Technical Aspects Colorectal cancer is the second cause of cancer deaths in the United States, second only to lung cancer in men and breast cancer in women. Colorectal cancer screening can be used to identify adenomatous polyps, the precursor lesion…
Conventional Imaging Technical Aspects Before cross-sectional imaging, the double-contrast enema was the foremost radiologic method for detection of colonic mucosal lesions and precancerous polyps. Diagnostic high-quality double-contrast barium enema examination is an art, requiring skillful maneuvering of the patient and…
Small bowel neoplasms remain a diagnostic challenge for radiologists and clinicians. The small bowel represents 75% of the total length of the gastrointestinal tract and more than 90% of the mucosal surface, but less than 2% of all gastrointestinal malignancies…
Normal intestinal wall thickness depends on the degree of bowel distention and the imaging modality. The normal jejunum wall thickness measures approximately 2 mm and the ileum 1 mm on enteroclysis. On computed tomography (CT), 3 mm is accepted as the upper limit…
Etiology Acute mesenteric ischemia of the small bowel has four major causes: (1) arterial embolism, (2) arterial thrombosis, (3) nonocclusive mesenteric ischemia, and (4) mesenteric venous thrombosis ( Table 26-1 ). Less common causes include aortic dissection, spontaneous dissection of…