腎シンチカメラによる腎space-occupying lesionsの鑑別診断の試み --初期イメージと後期イメージの比較--

Abstract

The early, dynamic and the late, static images of 99mTc-DMSA (dimercaptosuccinic acid) renal scintigram were applied to evaluate renal space-occupying lesions detected by IVP in 19 patients, consisting of 10 solitary renal cyst, 6 renal cell carcinoma, 2 renal pelvic transitional cell carcinoma and one renal cell carcinoma with a solitary renal cyst. The early image shows a dynamic vascular blood pool in the renal cortex and the late one a static renal cortical visualization. In the case of a solitary renal cyst, the cold area was revealed both in the early and the late images with almost 100 per cent diagnostic accuracy. In the case of renal cell carcinoma, 99mTc-DMSA uptake was seen in the early image and the cold area was noticed in the late image in accordance with the pathological lesion. However, 99mTc-DMSA uptake was not seen in the early image in which renal cell carcinoma had advanced necrotic lesions and tumor thrombi. In the case of renal pelvic tumor, tumor invasion to the adjacent renal parenchyma produced a cold area on the scintigram even if renal angiogram did not detect any abnormal vessels. It is impossible to make the final diagnosis of renal space-occupying lesions by using renal scintigram alone. However, 99mTc-DMSA renal scintigram consisting of both early and late images is a very useful tool for detecting characters of space-occupying lesions along with renal angiogram. In addition, this kind of renal scintigram can be performed advantageously in the following cases: (i) Poor-risk patients (ii) Patients with idiosyncrasy to the iodine contrast dye (iii) Debilitated geriatric and pediatric patients in which renal angiogram were not able to be taken.