Comparison of computed tomography findings between bacteremic and non-bacteremic acute pyelonephritis due to Escherichia coli

Figure 1 Grades of acute pyelonephritis. A: Grade 1 APN in the left kidney that is defined as a focal, wedge-shape, hypodense lesion; B: Grade 2 APN in the right kidney that is defined as multifocal or diffuse hypodense lesions; C: Grade 3 acute pyelonephritis in the left kidney that is defined as abscesses less than 2 cm within the APN lesion; D: Grade 4 APN in the left kidney that is defined as large abscess pockets more than 2 cm in the longest diameter. APN: Acute pyelonephritis.