CT angiogram sign : differentiation of malignant and benign lung consolidation

To assess the frequency of the CT angiogram sign, as seen on spiral CT and to evaluate the usefulness of this sign in the differentiation of benign and malignant lung disease. Sixty patients with lung consolidation, as seen on mediastinal window setting were studied retrospectively and the frequency of the CT angiogram sign was determined. In cases in which the sign was present, the following points were analysed; 1) discontinuity of vessels; 2) the avascular zone; 3) abnormal vessels, 4) displacement of pulmonary vessels, 5) separation of bronchovascular bundles. Of sixty patients with lung consolidation, 48 patients showed the CT angiogram sign; its frequency showed no significant statistical differences between benign and malignant disease (p greater than 0.05). There were, however statistically significant differences between discontinuity of vessels (malignant, 46%; benign, 15%; p=3D0.030) the avascular zone (malignant, 63%; benign, 20%; p=3D0.003) and separation of brocchovascular bundles (malignant, 60%; benign, 4%; p=3D0.001). In the case of abnormal vessels (malignant, 32%; benign 16%; p=3D1.588) and displacement of pulmonary vessels (malignant, 37%; benign, 16%; p=3D2.737) there were no statistically significant differences. The CT angiogram sign, as seen on spiral CT was nonspecific where the sign is present, angiogram sign, discontinuity of vessels, the avascular zone and separation of bronchovascular bundles may be useful signs for the diagnosis of central lung cancer with obstructive pneumonitis. (author)