Clinical impact of perinephric fat stranding detected on computed tomography in patients with acute pyelonephritis: a retrospective observational study

Perinephric fat stranding (PFS) is often detected on computed tomography (CT) in patients with acute pyelonephritis (APN). However, its clinical impact remains unclear. This study aimed to evaluate the clinical impact of PFS detected on CT in patients with APN. This retrospective observational study included patients with APN who underwent CT (median age, 79.5 years). Patients were classified into PFS (patients with PFS observed on CT) and non-PFS (patients without PFS observed on CT) groups, which were further classified into bacteraemia and non-bacteraemia groups. Clinical findings between the groups were compared. Among 194 patients who underwent CT, 111 (57.2%) patients demonstrated PFS. The rate of bacteraemia was significantly higher in the PFS group than in the non-PFS group (55.2 vs. 23.1%, p