Ileocecal Valve: Spectrum of Normal Findings at Double-Contrast Barium Enema Examination

Abstract

The ileocecal valve may show a spectrum of normal findings at double-contrast barium enema examination and may appear as a round, ovoid, or triangular structure with a maximal height of nearly 4 cm. The valve may be large, asymmetric, or smoothly lobulated, even in the absence of tumor.

CT Colonography with Computer-aided Detection: Recognizing the Causes of False-Positive Reader Results

“…position of 15% and 7%, respectively (36,37). However, confirmation that a CAD polyp candidate is related to the ICV does not preclude a pathologic condition on or adjacent to the ICV.…”

“…Furthermore, there is no consensus regarding the normal size of the valve; studies have reported a normal thickness for each ICV lip of as much as 1.5 cm and an overall maximal height of approximately 4 cm (37,39,40). On the basis of experience from air-contrast barium enemas, histologically normal valves may be large, asymmetric, or smoothly lobulated, making these characteristics generally nonspecific and unhelpful at CT colonography (37).…”

Imaging of the ileocaecal valve

“…It is formed by the protrusion of the circular muscle layer of the distal portion of the terminal ileum into the lumen of the large intestine [2]. This is usually at the level of the first (33%) or second (65%) complete haustral fold [3][4][5], but can occasionally occur as distal as the third haustral fold (2%) [4,5]. It is usually on the medial colonic wall (81-90%), but may occur on the lateral (1-15%) or posterior (3-8%) wall [3,4].…”

“…Although rigid measurements are not reliable in distinguishing a normal and enlarged ICV [3], it is on average 1.7 cm high (with a range of 1 to 4 cm) [3][4][5] and 2.8 cm wide (range 1 to 6 cm) [4,5]. In addition, 1.5 cm is considered the upper limit of normal for the height of a single lip of the valve [3].…”

“…The majority (85%) are smooth; the remainder appear lobulated (Fig. 1) [4,5]. The appearances on barium enema also depend on whether the valve is seen in profile on the medial or lateral wall, when it is described as a "shark's mouth", or en face on the posterior wall where it appears as a round filling defect with a central stellate appearance due to mucosal folds [6].…”