Computed tomographic diagnosis of unsuspected pyelonephritis in children

Objective: To emphasize the utility of computed tomography (CT) in the diagnosis of pyelonephritis in children with complex comorbidities. Methods: We retrospectively reviewed the CT imaging studies and medical records of 12 patients (8 girls, 4 boys; aged 2-18 years [mean 8.6 yr]) who did not have a classic presentation of pyelonephritis but were diagnosed by CT. All patients had fever at clinical presentation, and pyelonephritis was not suspected in any case. Two children had negative urine cultures before imaging. Results: All 12 patients had wedge-shaped areas of hypoattenuation on CT, 7 bilaterally; 10 had enlargement of an involved kidney; 5 had perinephric fat stranding; and 3 had focal abscesses. Conclusions: Although classic and uncomplicated pyelonephritis is a clinical diagnosis that does not require imaging, sometimes the presentation may be equivocal and the diagnosis unsuspected. Pyelonephritis is one of several potential sources of fever that can be simultaneously evaluated using CT. Using CT, the unsuspected diagnosis of pyelonephritis can be made and therapy initiated before the urine culture is positive.