Imaging Technologies in the Diagnosis and Treatment of Acute Pyelonephritis

Purpose The aim of this study was to evaluate the possibilities of ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) in diagnosing acute pyelonephritis (AP) and renal abscess. Patients and Methods Two hundred and seven patients with AP were followed up from 2010 throughout 2015. All the patients were divided into three groups. Group 1 included 113 (54.6%) patients with acute nonobstructive pyelonephritis; group 2 included 33 (15.9%) patients with acute obstructive pyelonephritis; and group 3 included 61 (29.5%) pregnant female patients with AP. All 207 patients with AP underwent ultrasound examination of the kidneys. Computed tomography (CT) was performed in 87 patients (42.0%). MRI was performed in 14 patients (6.7%). Results We identified the ultrasound (US), magnetic resonance (MR), and CT-signs of acute renal inflammation at different stages of the process. The main us-signs were decreased mobility of the kidney, its enlargement, thickened parenchyma, hydrophilic parenchyma and an impairment of corticomedullary differentiation. The typical CT-signs of AP were enlargement of the kidney with its thickened parenchyma and an impairment of corticomedullary differentiation. The main MR-signs of AP were enlargement of the kidney (>12 cm lengthwise), thickened parenchyma (<2 cm in the median segment of the kidney) and an impairment of corticomedullary differentiation. Conclusions Assessment of the structural and functional state of renal parenchyma and the upper urinary tract using techniques such as ultrasonography, CT, MRI contributes to more efficacious treatment of patients at different stages of AP and timely drainage with properly adjusted pathogenetic therapy at the infiltrative stage is instrumental in preventing purulent destructive forms of AP.