Added values of DMSA scan in management of patients with multicystic dysplastic kidney

Objectives In this study we evaluate the value of adding DMSA scan for postnatal imaging of Multicystic dysplastic kidney (MCDK).

Methods We retrospectively reviewed all patients (pts) with MCDK in our hospital from 2004 till 2012. Pts with other significant congenital abnormalities or incomplete clinical data were excluded. We reviewed the DMSA scan for all pts to determine the function of both kidneys. We also addressed the abnormalities in the contra lateral kidney as scaring and how can these modify our investigations. Fate of the MCDK was evaluated.

Results There were 126 pts (70 boys and 56 girls) with all postnatal imaging modalities (U/S, VCUG, and DMSA). Postnatal ultrasound confirmed the diagnosis of MCDK in 92% of pts and the remaining pts were diagnosed with renal atrophy or severe hydronephrosis. All pts found to have DMSA scan done 6-12 weeks postnatal and during follow-up if indicated. DMSA scan verified absent function in the affected kidney in 123 of the 126 pts (98%). It also showed scarring in the contra lateral kidneys in 14 pts (11%) all of them had abnormal renal ultrasound and /or VUR which required follow-up DMSA scan. Ultrasound of the contralateral kidney was normal in 105 pts (83%) while abnormalities were detected in 21 patients (17%). The association of VUR with hydronephrotic contra lateral kidneys was in 62%. VCUG demonstrated VUR into the contralateral kidney in 28 pts (22%) and in the ipsilateral MCDK in 16. Follow up ranged from 1 to 9 years (mean of 3.5). Fate of the MCDK included involution in 78 pts (62%) complete in 46 and partial in 32, nephrectomy was necessary in 6 patients (5%).

Conclusions DMSA scan had a significant added value as functional imaging to other postnatal imaging modalities in MCDK. It determines the function of both kidneys and assesses the contralateral kidney for possible scaring from associated VUR and managed accordingly to preserve its function.