Echographic diagnosis of acute pyelonephritis

Objective: We evaluated the contribution of ultrasound in detecting of acute pyelonephritis. The accurate diagnosis of acute renal infection can be a difficult clinical problem.

Materials and methods: Examinations in 150 patients of acute pyelonephritis. With current static imaging and realtime ultrasound, excellent definition of renal anatomy is possible, and abnormalities of renal architecture can be recognized early in the course of infection.

Results: Emphysematous pyelonephritis is a severe, necrotizing form of acute multifocal bacterial nephritis with extension of the infection through the renal capsule. This leads to the presence of gas within the kidney substance and in the perinephric space. Persons with diabetes account for 85-% of cases, although some cases have occurred in patients who had obstruction without diabetes. Acute multifocal bacterial nephritis with a similar process throughout the kidney that produces liquefaction and abscess formation. Ultrasonography can help detect renal emphysema but do not help in localization. The suppurative material of the abscess is located between the renal capsule and the surrounding renal fascia. The material is secondary to chronic or recurrent pyelonephritis, rupture or extension of a suppurative process from within the kidney, or dissemination (blood, lymph) or direct extension from other sites of infection. Although it is usually confined to the perinephric space, it may extend to the colon, flank, groin, lung (empyema, nephrobronchial fistula), paracervical area, peritoneal cavity, psoas muscle, skin surface, or subphrenic space.

Conclusion: Ultrasonography is the imaging study of choice for the diagnosis of urinary tract structural abnormalities