CT and Tc-99m-DMSA scintigraphy in adult acute pyelonephritis: A comparative study

Purpose: The aim of this prospective study was to evaluate the relative val ue of CT and Tc-99m-DMSA scintigraphy in the diagnosis of acute pyelonephri tis (APN) in adult patients suspected of having urinary tract infection. Method: The study was conducted in 36 patients presenting with symptoms sug gestive of urinary tract infection. Plain B-mode sonography, CT with contra st medium, and Tc-99m-DMSA scintigraphy of the kidneys were performed in al l patients. Both CT and Tc-99m-DMSA scintigraphy were performed within 72 h after admission. Results: Twelve patients with clinical and biological signs of urinary trac t infection had no CT or Tc-99m-DMSA scintigraphy abnormalities. Among thes e patients, lower urinary tract infection was found in 10 patients and 2 pa tients had ureteral obstruction. In the 24 remaining patients, the diagnosi s of APN was made. Among these patients, a correlation was found between CT and Tc-99m-DMSA scintigraphy in 11 cases. In two cases, both examinations were normal, and in nine cases, both were abnormal. In 11 cases of the 13 r emaining patients, abnormal CT was found with normal Tc-99m-DMSA scintigrap hy, whereas the 2 last cases had normal CT and abnormal Tc-99m-DMSA scintig raphy results. In two cases, bilateral lesions found on CT manifested as un ilateral abnormalities on Tc-99m-DMSA scintigraphy images. Conclusion: The diagnosis of APN in adult patients is based on clinical pre sentation and biological findings. Few studies have compared Tc-99m-DMSA sc intigraphy with CT in the detection of parenchymal involvement in APN. We c onclude that CT is more accurate than Tc-99m-DMSA scintigraphy in the detec tion of APN lesions in adult patients.