OBJECTIVE To investigate the distribution of pathogenic bacteria, imaging manifestations on single photon emission computed tomography/computed tomography (SPECT/CT) and the role of Wnt/β-catenin pathway in upper urinary tract infections.

METHODS From Jan. 2021 to Jan. 2024, 53 patients with upper urinary tract infection and 53 urinary calculi patients without upper urinary tract infections who had urinary system stones were selected from the Second Hospital of Tianjin Medical University as the infected group and the non-infected group, respectively. The distribution of pathogens in the infected group, SPECT/CT imaging manifestations and SPECT/CT imaging manifestations after 7 days of anti-infective treatment were statistically analyzed and compared. The levels of Wnt-1 and β-catenin in both groups and the infection group before and after 3 and 7 days of anti-infective treatment were compared. The diagnostic values of Wnt-1 and β-catenin for urinary calculi complicated with upper urinary tract infection were analyzed.

RESULTS A total of 53 strains were yielded from the middle-segment urine of the infection group, predominantly gram-negative bacteria. SPECT/CT imaging showed small nodular dense shadows were in the upper segment of left ureter, the upper segment of the ureter, renal pelvis and calyx dilated, and visible striated shadows were around the kidney after 7 days of anti-infective treatment, the cystic low-density shadow under the left renal capsule was basically absorbed, the perirenal strip shadow slightly reduced, but the perinephric fascia remained thickened, and the surrounding fat space was blurred. Wnt-1 and β-catenin levels elevated in the infection group compared with the non-infection group (P < 0.05). The area under the curve of combined detection of Wnt-1 and β-catenin was 0.907.

CONCLUSIONS Gram-negative bacteria are the main pathogens causing upper urinary tract infections in patients with urinary calculi. SPECT/CT imaging shows inflammatory changes, and the Wnt/β-catenin pathway is activated. The combination of Wnt-1 and β-catenin has high diagnostic value. After anti-infective treatment, the inflammation showed on SPECT/CT imaging improves and the Wnt/β-catenin pathway is inhibited.