Two cases of intrathoracic lesion adjacent to the diaphragm successfully diagnosed by direct coronal CT

Direct coronal CT-scanning is able to generate images along the longitudinal axis of the body. We applied this method for diagnosis of intrathoracic lesions adjacent to the diaphragm. Case 1 was a 59-year-old female and case 2 was a 70-year-old female. In both cases abnormal shadows were pointed out in the left lower lung field overlapping the silhouette of the diaphragm on plain chest X-ray films. These shadows had sharp margins and homogenous density but more detailed qualitative analysis could not be obtained by conventional X-ray examination. Direct coronal CT revealed that both shadows had tumor-like structure adjacent to the diaphragm and only compressed pulmonary architecture. Furthermore the CT number revealed that those lesions were composed of fatty tissues. In case 1 the histology of the biopsied specimen obtained under thoracoscopy was soft fatty tissues. This finding confirmed the clinical diagnosis of benign lipoma. Tumorous lesions of the diaphragm are supposed to be rare and are often difficult to diagnose roentogenographically. But direct coronal CT is helpful to analyse lesions adjacent to the diaphragm. (authors)