Assessment of radioisotopic micturating cystography for the diagnosis of vesicoureteric reflux in renal transplant recipients with acute pyelonephritis.

BACKGROUND

The gold standard for documenting vesicoureteric reflux is direct (retrograde) micturating cystography (MC). In children, radioisotopic MC has been advocated for increased sensitivity and lesser radiation exposure. In renal transplant recipients, where reflux can induce acute pyelonephritis, this technique has not been evaluated. The aim of this study was to assess the radioisotopic technique in these patients.

METHODS

Seventeen renal transplant recipients had developed acute pyelonephritis following the surgical grafting procedure. They were investigated using both MC techniques. Radioisotopic MC was performed using 99mTc-pertechnetate.

RESULTS

Reflux was documented in nine patients by radioisotopic MC but in only seven with the conventional technique. All negative patients remained symptom free after the pyelonephritis was cured and it was assumed that they had no reflux. Consequently, using the radioisotopic MC as gold standard, the conventional X-ray technique had a sensitivity of 78% and a specificity of 100%.

CONCLUSIONS

Direct radioisotopic MC allowing continuous cystogram recording is more accurate than conventional X-ray MC for the diagnosis of vesicoureteric reflux in transplanted patients with acute pyelonephritis.