Use of magnetic resonance imaging to assess renal structure and function in reflux nephropathy.

AIM: Despite numerous potential advantages, the role of magnetic resonance imaging (MRI) in depicting structural and functional abnormalities in kidney disease has not been well addressed. In reflux nephropathy in particular, nuclear scintigraphy (NS) has become the diagnostic gold standard, however, other imaging modalities may be required for adequate clinical appraisal. We therefore assessed the use of MRI in reflux nephropathy, comparing findings with those obtained using conventional imaging techniques.

METHODS: Eight women with likely or proven reflux nephropathy underwent MRI scanning with structural and split functional appraisal. Results were compared with those obtained with ultrasound and NS.

RESULTS: As expected, structural abnormalities were better defined with MRI than with ultrasound. NS findings were confirmed in most, but not all, MRI scans: NS and ultrasound had failed to identify scarring and cyst development in one patient. A close correlation was observed between MRI and NS renal functional estimates, regardless of whether whole kidney (r(2) = 0.87, P = 0001) or region of interest (r(2) = 0.99, P < 0001) techniques were used. Bland Altman plot analysis suggested methods were interchangeable.

CONCLUSION: MRI provided more accurate diagnostic information structurally than ultrasound and MRI and split renal functional estimates correlated well with NS. It achieved in one study what otherwise required additional scans and without the need for ionizing radiation. These results suggest it should be considered as a diagnostic tool for reflux nephropathy.