Patterns of excretion of radioactive chelates in obstructive uropathy.

Radioactive chelates such as 99mTc-DTPA are advantageous in ranal imaging, particularly in defining functional and morphological abnormalities of the excretory tract. In a review of more than 200 studies, 19 cases of lower-tract disease were diagnosed by the gamma camera image alone. In 16 of them, the diagnosis was confirmed by excretory urography. Normal radionuclide patterns are described and compared with the characteristic findings in caliectasis, hydronephrosis, and hydroureter. By facilitating evaluation of renal perfusion, renal glomerular function, and gross renal structure as well as good difinition of excretory function, radioactive chelate imaging is ideally suited for use as general screening test.