usefulness of inter-renal resistive index difference in diagnosing acute unilateral ureteric obstruction due to calculus

ABSTRACT

To evaluate the usefulness of inter-renal resistive index difference in diagnosis of acute unilateral ureteric obstruction due to calculus. Case Control Study was conducted in Department of Radiology, Combined Military Hospital Lahore, from August 2005 to February 2006. Sixty patients were divided in two groups of 30 each group I, 30 patients with unilateral acute ureteric colic due to ureteric calculus; and group II, 30 patients having no symptoms and with a normal ultrasound [as controls]. Interlobar arteries were examined by Colour Doppler ultrasound in upper, mid and lower renal pole with a two to five millimetre sample volume to calculate average resistive index. Inter-renal resistive index difference [deltaRI] was then calculated. Statistically significant difference was observed in the inter-renal resistive index difference [deltaRI] measurements with mean value in the case group of 0.09 compared to 0.021 in controls. Average intrarenal resistive index measurement in the obstructed kidney was .69 compared to 0.58-0.59 in the control group. Measurement of inter-renal resistive index difference in patients with ureteric colic improves diagnostic accuracy of ultrasound in distinguishing between obstructive and non-obstructive dilatation