Value of ⁹⁹Tc^m-DMSA renal SPECT/CT imaging in the diagnosis of upper urinary tract infection in adults

Objective: To explore the diagnostic value of ⁹⁹Tc^m-dimercaptosuccinic acid (DMSA) renal SPECT/CT imaging in adult upper urinary tract infection. Methods: From September 2017 to December 2019, ⁹⁹Tc^m-DMSA renal SPECT/CT imaging and clinical data of 109 patients (14 males, 95 females; age: 23-85 (60.0 ± 14.1) years) suspected of upper urinary tract infection from Beijing Hospital were retrospectively analyzed. Final clinical diagnosis was regarded as the diagnostic standard. The diagnostic efficacy of ⁹⁹Tc^m-DMSA renal SPECT/CT imaging was analyzed and compared with that of ⁹⁹Tc^m-DMSA renal SPECT imaging. The imaging features of SPECT/CT imaging in upper urinary tract infection were analyzed. The differences between the diagnostic methods were analyzed by using X² test or Fisher's exact test. Results: Of 109 patients, 91 were diagnosed as upper urinary tract infection by ⁹⁹Tc^m-DMSA renal SPECT/CT imaging, with the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 100% (86/86), 78.26% (18/23), 94.51% (86/91), 18/18 and 95.41% (104/109), respectively. With the application of low-dose CT, the diagnostic specificity of SPECT/CT was significantly higher than that of SPECT (52.17% (12/23); P = 0.014), and the causes of upper urinary tract infection were found in 5.81% (5/86) of patients with the help of CT. There were 10 (29.41%, 10/34) patients with chronic pyelonephritis had typical signs of renal scar on SPECT/CT imaging. Excluding the patients with typical renal scar, 11.54% (6/52) and 37.50% (9/24) of patients with acute and chronic pyelonephritis had decrease or defect focus ≤ 2 (X² = 6.987, P = 0.008). Conclusions: ⁹⁹Tc^m-DMSA renal SPECT/CT has good clinical value in the diagnosis of adult upper urinary tract infection. Compared with ⁹⁹Tc^m-DMSA renal SPECT, ⁹⁹Tc^m-DMSA renal SPECT/CT can effectively improve the diagnostic specificity and explore the causes of upper urinary tract infection such as urinary tract obstruction and stones. (authors)