DOPPLER-DUPLEX ULTRASOUND IN RENAL COLIC

Objective: To determine the role of intrarenal Doppler ultrasound (US) in patients with renal colic and to establish the usefulness of this diagnostic method. Materials and methods: In 121 patients with renal c olic and 70 healthy individuals, 382 kidneys were examined with color duplex US. Mean intrarenal-arterial resistive index (RI), and the diff erence of mean RIs (dRI) between both kidneys were determined. In 64 p atients, RI and dRI were compared with urographic findings (time of de lay pyelogram between both kidneys). Results: In the 70 healthy indivi duals, RI was 0.62 +/- 0.045 and dRI 0.018 +/- 0.01. In the 121 patien ts with renal colic, RI (0.71 +/- 0.06) was significantly superior (P < 0.001) with respect to the opposite kidney, with a dRI of 0.09 +/- 0 .055. In a correlation performed in 64 patients with urographic findin gs among color doppler US, with a RI greater than or equal to 0.70 and /or dRI greater than or equal to 0.06 as an indicative value of obstru ction, sensitivity and specifity were 91.8% for patients with delayed pyelogram (n = 37 patients), and 48.1% for patients with nondelayed py elogram (n = 27 patients) with a specificity of 92.8% with respect to the group of normal patients. In the group of patients with delayed py elogram, RI was significantly superior (P < 0.05) in patients with an evolution time greater than 24 hours, in patients with proximal ureter al obstruction and in patients who had signs of pyelonephritis. There were no significant differences in the group of patients with nondelay ed pyelograms. Conclusion: Color Doppler US is useful to fundamentally evaluate the consequences of the obstruction on renal function. Other factors such as evolution time of the symptomology, obstruction level , or existence of pyelonephritis can alter the US-Doppler values.