ABSTRACT

Acute pyelonephritis (APN) is a major cause of morbidity in children with urinary tract infection and can result in irreversible renal scar-ring. Renal scarring can be prevented by early diagnosis and aggressive tre-atment. DMSA renal cortical scintigraphy is regarded as the gold standard method for the diagnosis of APN. The purpose of our prospective study was to determine the effectiveness of contrast-enhanced PDUS in the diagnosis of APN.

Twenty-three patients (20 female, 3 male; 5 mon-ths to 9 years) were evaluated with B-mode ultrasound, PDUS, contrast-enhanced PDUS and Tc-99m-DMSA scintigraphy. Scintigraphy was consi-dered the gold standard method. The sonographic findings were correlated with scintigraphic data.

The sensitivity rates of B-mode ultrasound, PDUS and contrast-enhanced PDUS were (respectively) 30%, 78% and 86%; specificity rates were 84.09%, 59.09% and 79.54%; accuracy rates were 64.49%, 65.94% and 81.88%; positive predictive values were 51.72%, 52.00% and 70.49%; and the negative predictive values were 67.88%, 82.53% and 90.90%.

The sensitivity of B-mode US in the diagnosis of APN is very low and the diagnostic value of this modality is doubtful. The sensitivity of PDUS is high enough but the specificity of this technique is lower than ex-pected. Contrast-enhanced PDUS achieved high sensitivity and specificity rates. We think that this imaging modality can be part of the diagnostic and follow-up protocol for APN and even may replace scintigraphic techniques.