DMSA renal scans in adults with acute pyelonephritis

Area of Science:

• Nuclear Medicine
• Nephrology
• Infectious Disease

Background:

• The technetium-99m dimercaptosuccinic acid (DMSA) scan is the gold standard for detecting renal parenchymal scarring.
• Recent evidence suggests DMSA scans are valuable for imaging renal involvement in acute pyelonephritis in both children and adults.

Purpose of the Study:

• To assess the findings of acute technetium-99m dimercaptosuccinic acid (DMSA) scans in adult patients hospitalized with acute pyelonephritis.
• To evaluate the diagnostic utility of DMSA scans in acute pyelonephritis and the resolution of associated defects.

Main Methods:

• Prospective assessment of 81 adult patients hospitalized with acute pyelonephritis.
• Diagnosis criteria included fever, loin pain/tenderness, and infected urine (primarily Escherichia coli).
• Patients underwent DMSA scans, blood cultures, hematological/biochemical screening, C-reactive protein (CRP) measurement, and urinary tract ultrasonography. Follow-up DMSA scans and intravenous urograms were performed as needed.

Main Results:

• 46% (37/81) of patients showed abnormalities on the initial DMSA scan, including single defects, multifocal defects, features of scarring, or shrunken kidneys.
• Patients with abnormal scans had higher CRP concentrations.
• Of 24 patients with focal or multifocal defects followed up, 75% (18/24) showed complete resolution by six months; the remainder had persistent findings like reflux nephropathy or renal cysts.

Conclusions:

• The technetium-99m dimercaptosuccinic acid (DMSA) scan is a sensitive tool for diagnosing acute pyelonephritis in adults.
• Many DMSA scan defects associated with acute pyelonephritis resolve over time, indicating the transient nature of the inflammatory process.
• In adults with acute pyelonephritis, the DMSA scan may be the most valuable renal imaging procedure.