CT of the carcinoma of the esophagus

Precise diagnosis of the extent of the esophageal carcinoma is very valuable for determining the necessity for operations and for the planning of radiation therapy. CT is able to visualize esophageal carcinoma with high accur acy in close anatomical correlation with the surrounding organs. We divided CT figure of esophageal carcinoma into 5 t ypes and 5 sub-types morphologically: 1. normal like type which could not be ditected on CT image. 2. thickened wall type (a. partial, b. diffuse). 3. tumorous type (a. non-expansive, b. expansive, c. compressive and expansive) 4. invasive type and 5. unclassified type. The correlation between each CT type and the A factor was studied and shown to be close correlation between them. The CT findings were studied retrospectively, and the original diagnostic criteria concerning the A factor was established. This criteria was composed of basic CT findings, that is, the presence of low density zone by fat tissue, and sub-CT findings such as a. the degree of contact between the tumor and the surrounding organs, b. the presence of compressive changes of the surrounding organs, c. blurring or irregularity of the wall of the surrounding organs, d. the contact angle between the tumor and aorta, and e. the size of the tumors. The accuracy in diagnosing the A factor according to this criteria was shown to be as high as 90%, and therefore this criteria proved to be very useful of diagnosing the A factor. The diagnostic capability for the N factor was studied in regard to both size and anatomical site of the lymphnodes. In the mediastinum, 55% of all lymphnodes over 1 cm in size could be detected by CT, while in the abdomen, 69% of all lymphnodes over 1 cm could be detected. And in the diagnosis of the progression degree of the N factor, CT proved to be capable of showing a relatively high diagnostic ratio of 66%. (J.P.N.)