The Roentgenologic Diagnosis of Diseases of the Colon

THE most common organic diseases of the colon are neoplasms, diverticulitis, tuberculosis, and chronic ulcerative colitis. The roentgenologic study of the colon in these conditions reveals obstruction of the bariumized medium, abnormal changes in its rate of passage, and transitory or constant deformities in the outline of the colon. Of the diseases mentioned, a differential diagnosis based on pathognomonic roentgenologic evidence can usually be made in only one condition, diverticulitis. In cases of tuberculosis, neoplasm, and chronic ulcerative colitis, the roentgen ray will usually reveal evidence of a lesion, but this evidence is in itself insufficient for a histopathologic diagnosis. To elicit the roentgenologic signs of colonic disease either the opaque meal or the opaque enema is applicable, and each method has its advocates. Technique of the Barium Meal The patient is instructed to abstain from catharsis for a day or two before and during the examination. On the morning of the examining day he is fed a bariumized meal of sufficient quantity to fill, at one time, the cecum and at least a portion of the ascending colon. Every half hour from the sixth to the ninth hour, the colon is examined fluoroscopically and roentgenographicaIIy, in an endeavor to visualize the proximal colon at its optimum filling (Fig. 1). Final examinations are made from eighteen to seventy-two hours later, to determine the time of complete emptying of the colon. The patient is instructed to continue his usual habits of eating and exercise, in order to maintain the customary conditions. Advantages and Disadvantages of the Barium Meal The advantage of the barium meal lies in the fact that it may be used to reveal the proximal limits of an obstructive lesion in the colon. It will demonstrate the rate of emptying of the bowel. It may be of aid in visualizing proximal portions of the colon which are hidden by redundant loops, during the administration of the enema. One disadvantage of the barium meal is that in cases of marked stenosis acute obstruction may result from its use (Erdmann). Another, is that when the colon is apparently normal, as shown at exploration or necropsy, it may be im­possible to demonstrate a well-filled cecum or ascending colon. Normally, such portions of the gut should be weII visualized in from four to six hours after the meal is given (Hertz). However, in some cases these portions are best filled in less than four hours, or in more than six hours, and even as late as nine to twelve hours. Furthermore, this examination, conducted without purgation or cleansing of the colon, may reveal pseudo-defects caused by fecal masses. It is apparent, therefore, that this type of examination entails a great amount of labor to the roentgenologist, and may be of considerable incon­venience and hardship to the patient, especially if heis markedly debilitated.