Role of dynamic MRI in replacing the isotope renogram in the functional evaluation of PUJO.

INTRODUCTION : Pelviureteric Junction obstruction is one of the most common cause of Hydronephosis and continues to present a challenge to Radiologists and Urologists, who are unable to accurately predict which patient will benefit from surgery. Traditional imaging tests have emphasized detection and grading of Hydronephrosis with Sonography and determination of Renal function and obstruction with Scintigraphy. The classification of the kidney as obstructed does not predict progressive loss of function and does not identify which patient will benefit from surgery. The increase in the detection of asymptomatic Pelvi-Ureteric Junction Obstruction, because of the increasingly widespread USG has exacerbated this problem. Although, pain and recurrent infections are independent indications for surgery, these are much less commonly seen. In many cases, Pelvi-Ureteric Junction Obstruction is self limited, with no long term sequelae. As a result of this variable outcome, Management of Pelvi-Ureteric Junction Obstruction is controversial, with some authors recommending early surgery and others advocating simple observation. AIM & OBJECTIVES : The aim of this study is : To find out the Extent of obstruction in Pelvi-Ureteric Junction Obstruction. To find out the functional potential of the Hydronephrotic Kidney. To determine, if dynamic contrast enhanced MR Urography could replace Isotope Renogram in the functional evaluation of Pelvi-Ureteric Junction Obstruction. MATERIALS AND METHODS : Period of Study: January 2008 – March 2010. Inclusion Criteria: All those patients diagnosed to have Pelvi-Ureteric Junction Obstruction based on USG, IVU, CT. Symptomatic patients with Pelvi-Ureteric Junction Obstruction were included in our study. The Institutional review board at our hospital approved the study and informed consent was obtained from all the patients. All these patients were investigated with Isotope Renogram and subsequently, subjected to Dynamic MRI. Exclusion criteria: Patients with structural defects like Duplex system, Horse – shoe kidney. Patients with B/L PUJO. Previous surgery. Patients with Pacemaker & Metallic Implants. Claustrophobic patients. CONCLUSION : Using Dynamic MRI, analysis of Renal function is similar to Renal Scintigraphy, because of superior spatial and contrast resolution. MR Urography may be more sensitive than Renal Scintigraphy in analyzing poorly functioning system. While MR Urography, costs more than renal Scintigraphy, the information obtained is superior to currently used methods. As with other medical technologies, the cost will decrease as its use becomes more widespread. Different MRI techniques can be combined to establish a “one stop imaging examination” that can replace different imaging methods used for morphological, etiological and functional evaluation of Pelvi–Ureteric Junction Obstruction