Volvulus is a twisting of the bowel which produces luminal occlusion. When it occurs in the cecum, the clinical findings are those of intestinal obstruction of sudden onset, the cause of which is obscure. The radiologic observations, however, may be strikingly diagnostic. In spite of the fact that cecal volvulus constitutes a radiologic entity, there is a remarkable paucity of comment on this type of acute abdominal crisis in the radiologic literature. Indeed, during the past fifteen years, not a single American radiologic journal has published an original article on volvulus of the cecum. The present report is based on 7 proved cases and emphasizes the radiologic criteria for diagnosis. The term “volvulus of the cecum” is somewhat of a misnomer, since in every case more or less of the ascending colon and terminal ileum participates in the twist. The first description of cecal volvulus was made by Rokitansky in 1841 (29). Since that time, many cases have been reported, and by 1942, Wolfer, Beaton and Anson were able to collect over 300 examples from the literature (33). During the past ten years, at least 60 additional cases have been described (6, 8, 10–12, 16, 17, 20, 21, 25, 28, 34). Most of these earlier cases were discovered on the autopsy table, and it was not until recent years that survival became the rule rather than the exception (6). In a review of 100 reported cases, Donhauser and Atwell, in 1949, stressed the grave prognostic implications of gangrene and pointed out that most of the survivors have been operated upon within twenty-four hours after the onset of symptoms (8). Early recognition, then, is imperative. It is possible only where awareness of the entity coincides with knowledge of its clinical and roentgenographic manifestations. Etiology The factors implicated in the precipitation of volvulus of the cecum are legion. Previous operations (7, 23), bands (25), tumors (25), hernias (5), violent coughing (33), pregnancy (2, 18, 24, 26), mesenteric cysts (22), typhoid fever (13), excessive physical exertion (26, 33), over-eating (26, 31), abdominal trauma (33), diet (13), constipation (25)—all these and many more possible causes have been mentioned. In our own cases, it was impossible to discern any common precipitating factor. It is probably more important to understand the basic anatomic abnormality without which volvulus could not occur, namely, excessive mobility of the cecum and ascending colon. The embryonic intestine, which at four weeks of life is a simple tube, shortly thereafter undergoes ventral flexion, forming a horizontal U-shaped loop (Fig. 1). At this time, the cecum first appears as a bulge in the caudal half of the loop; by six weeks, rotation of the loop about the superior mesenteric artery brings the cecum from an inferior to a superior position to the left of the mid-line.