ABSTRACT: We evaluate the accuracy of nonenhanced helical computerized tomography (CT) and Doppler ultrasonography for the diagnosis of renal colic.
Our study includes 109 patients, with 218 kidneys, who presented with unilateral flank pain. All patients underwent nonenhanced helical CT, Doppler ultrasonography and excretory urography (IVP). CT was evaluated for the presence of ureteral stones and manifestation of ureteral obstruction. For Doppler ultrasonography the renal resistive index was measured for the left and right kidneys in each patient, and change in resistive index between ipsilateral and contralateral kidneys was calculated and considered positive for ureteral obstruction with values 0.04 or greater. As a reference standard, absence of obstruction was considered if IVP was negative and the cause of flank pain was confirmed not to be urological. Obstruction was diagnosed not only by positive IVP, but also by patient followup until passage or retrieval of ureteral stones. Results of CT and change in resistive index were compared with those of the reference standard.
Unilateral ureteral obstruction was confirmed in 52 patients, while no obstruction was found in 57. Of the 57 patients without ureterolithiasis the change in resistive index results was negative in all patients with a specificity of 100%, while CT was negative in 55 with a specificity of 96%. Of the 52 patients with ureteral obstruction CT was positive in 50, and change in resistive index was positive in 47 with a sensitivity of 96% and 90%, respectively, with a difference of no significant value.
Nonenhanced helical CT and change in resistive index are sensitive and specific tests that can contribute significantly to the diagnosis of acute unilateral renal obstruction. They can replace IVP, particularly in situations in which it is undesirable.
The Journal of Urology 05/2001; 165(4):1082-4. · 3.75 Impact Factor
ABSTRACT: To investigate the value of the renal resistive index (RI) in the identification of acute renal obstruction in pregnant women.
The study included 22 pregnant women with acute unilateral ureteral obstruction due to a stone disease (group A), 71 normotensive pregnant patients without loin pain (group B), and 20 nonpregnant women of child-bearing age with both kidneys normal (group C). All patients underwent Doppler ultrasound (DUS) with determination of the RI and the difference between the RI of the corresponding and contralateral kidney (DeltaRI). The RI and DeltaRI was considered positive for obstruction with a value of 0.70 or greater and 0.04 or greater, respectively. Ureteral obstruction was confirmed by several clinical, radiologic, and endoscopic findings. The sensitivity, specificity, and overall accuracy of RI and DeltaRI for the diagnosis of acute unilateral ureteral obstruction were calculated.
In group A, kidneys with ureteral obstruction (n = 22) had a mean RI of 0.69 +/- 0.03; the contralateral normal kidneys (n = 22) had a mean RI of 0.63 +/- 0.03, a significant difference (P <0.0001). The mean RI of all kidneys in group B (n = 142) and all kidneys in group C (n = 40) was 0.64 +/- 0.05 and 0.62 +/- 0.04, respectively; the difference was not statistically significant. A comparison between the mean RI of the normal kidneys of group A and all the kidneys of groups B and C revealed no significant difference. The mean RI of the obstructed kidneys in group A was significantly higher than the mean RI of all the kidneys in groups B and C. Similarly, the mean DeltaRI of group A was significantly higher than the mean DeltaRI of groups B and C (0.06 +/- 0.01 versus 0.006 +/- 0.003 versus 0.006 +/- 0.004, respectively). The RI was sensitive in 45%, specific in 91%, and accurate in 87%. The corresponding values for DeltaRI were 95%, 100%, and 99%.
The DeltaRI is a sensitive and specific test that can replace intravenous urography in the diagnosis of acute unilateral ureteral obstruction in pregnant women.
Urology 03/2000; 55(3):344-7. · 2.43 Impact Factor
ABSTRACT: To investigate the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on the findings of Doppler ultrasonography (DU) in patients with acute unilateral renal obstruction.
The study included 60 patients (120 kidneys) with unilateral loin pain suspected to be of renal origin. All patients were evaluated using renal ultrasonography (US) and intravenous urography (IVU) during the attack of loin pain and before giving any medication. Then the patients were given 75 mg diclofenac sodium and DU studies were repeated at 6 and 12 h. In 10 patients with acute renal colic, DU was possible 12-24 h after the relief of ureteric obstruction. The mean resistive index (RI) and DeltaRI at baseline were compared with the mean values 6 and 12 h after giving diclofenac. The RI and DeltaRI were considered positive at values >/=0.70 and >/=0.06, respectively. The sensitivity, specificity and overall accuracy of RI and DeltaRI values before and after giving diclofenac were calculated using IVU as the reference standard.
IVU showed that both kidneys were normal in 20 patients that 40 had unilateral obstruction. At baseline, the mean (sd) RI was 0.72 (0.06) in the 40 obstructed kidneys, significantly higher than the RI of 0.60 (0.06) for the 60 normal kidneys (P<0. 001). Six hours after giving diclofenac, the mean RI of normal kidneys remained stable and that of the obstructed kidneys decreased significantly to 0.67 (0.06) (P<0.001) and was almost stable at 12 h. Nevertheless, the mean RI of the obstructed kidneys remained significantly higher than that of the normal kidneys at 6 and 12 h after diclofenac. The mean DeltaRI decreased significantly from 0.11 (0.04) at baseline to 0.06 (0.04) at 6 h after diclofenac (P<0.001) and remained almost stable at 12 h. In the 10 patients undergoing DU after the relief of obstruction, the mean RI returned to normal. At baseline, RI was sensitive in 70% and specific in 98%, while DeltaRI was sensitive in 88% and specific in all cases. Six hours after diclofenac, the specificity of RI and DeltaRI remained stable while the sensitivity decreased significantly to 50% and 68%, respectively.
NSAIDs significantly decrease the RI of acutely obstructed kidneys, causing a significant reduction in the sensitivity of DU values identifying acute renal obstruction. To evaluate acute loin pain, DU should be carried out while the patient is in pain and before giving NSAIDs.
BJU International 09/1999; 84(3):249-51. · 2.84 Impact Factor
ABSTRACT: To study the role of Doppler ultrasonography (DU) in the diagnosis of acute unilateral renal obstruction.
In all, 117 patients with suspected renal colic were evaluated by intravenous urography (IVU) and DU, with determination of the resistive index (RI) and the difference between the RI of ipsilateral and contralateral kidneys (deltaRI). RI and deltaRI were considered positive with values of > or = 0.70 and > or = 0.06, respectively. IVU results were considered the 'gold standard' with which renal DU findings were compared.
IVU showed both kidneys to be normal in 49 patients and unilateral ureteric obstruction with a normal contralateral kidney in 68. The mean (SD) RI was 0.73 (0.05) in 68 obstructed kidneys, significantly higher than the mean RI of 0.64 (0.05) in 166 normal kidneys (P<0.001). The deltaRI in patients with unilateral obstruction was significantly higher than that in patients with both kidneys normal, at 0.09 (0.05) and -0.001 (0.02), respectively (P<0.001). For all the patients, RI was sensitive in 77% and specific in 83%, and deltaRI was sensitive in 88% and specific in 98%. Obstructed kidneys showing delayed pelvicalyceal filling with excretion of contrast medium (n=42) had significantly higher values of RI and deltaRI than obstructed kidneys without delayed filling (n=26). The RI and deltaRI were more sensitive in the former group. Among patients with obstruction, the RI did not relate to the time of delay of filling with contrast medium, the duration of renal colic or the level of ureteric obstruction.
Renal DU is a sensitive and highly specific test that can contribute significantly to the diagnosis of acute unilateral renal obstruction. It can replace the IVU, particularly in situations where IVU is undesirable.
BJU International 04/1999; 83(4):378-82. · 2.84 Impact Factor