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Functional evaluation of the urinary tract by duplex Doppler ultrasonography in patients with acute renal colic.

Sayani R, Ali M, Shazlee K, Hamid RS, Hamid K - Int J Nephrol Renovasc Dis (2011)

Bottom Line: The mean RI for obstructed kidneys was 0.67 (0.048), which was significantly higher (P-value <0.05) than a mean RI of contralateral normal kidneys 0.59 (0.04).The mean delta RI in patients with unilateral ureteric obstruction was significantly higher than that in patients with normal kidneys, at 0.076 (0.03) and 0.03 (0.05), respectively.However, due to relatively low sensitivity for detection of partial obstruction, DDU cannot replace IVU as the standard imaging technique.

View Article: PubMed Central - PubMed

Affiliation: Radiology Department, Aga Khan University Hospital, Karachi, Pakistan.

ABSTRACT

Purpose: To determine the role of duplex Doppler ultrasonography (DDU) in patients with acute unilateral renal obstruction.

Subjects and methods: A total of 161 patients with suspected renal colic due to urolithiasis were evaluated by DDU followed by intravenous urography (IVU). The mean intra-arterial resistive index (RI) and the difference of mean resistive index between both kidneys (delta RI) were determined for each person. An RI value of ≥0.70 and a delta RI value of ≥0.06 were taken as the discriminatory threshold for obstruction. IVU results were considered the " reference standard" against which renal DDU findings were compared.

Results: IVU showed both kidneys to be normal in 51 patients and with unilateral ureteric obstruction in 110 patients. The mean RI for obstructed kidneys was 0.67 (0.048), which was significantly higher (P-value <0.05) than a mean RI of contralateral normal kidneys 0.59 (0.04). The mean delta RI in patients with unilateral ureteric obstruction was significantly higher than that in patients with normal kidneys, at 0.076 (0.03) and 0.03 (0.05), respectively. In patients with complete obstruction, sensitivity of RI and delta RI were 77.5% and 92.5% with a specificity of 84.3% and 90.1%, respectively. In patients with partial obstruction, the sensitivity of these values was 22.8% and 62.8% with a specificity of 84.3% and 90.1%.

Conclusion: Delta RI is more sensitive and specific than RI in acute renal obstruction. However, due to relatively low sensitivity for detection of partial obstruction, DDU cannot replace IVU as the standard imaging technique.

No MeSH data available.


Related in: MedlinePlus

Subsequent IVU of same patient shows complete obstruction on right side due to a distal ureteral calculus.
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f4b-ijnrd-5-015: Subsequent IVU of same patient shows complete obstruction on right side due to a distal ureteral calculus.

Mentions: Our study showed that elevation of RI and delta RI was related to the degree of ureteric obstruction. In our study the RI was above the 0.70 threshold in 77.5% of cases of complete urinary obstruction and in 22.8% of cases of partial obstruction. Similarly, delta RI was elevated in 92.5% cases of complete obstruction and in 62.8% cases of partial obstruction (Figures 4A and B). This can be explained by the fact that ureteral pressure in partial obstruction is not sufficiently elevated to induce an increase in renal vascular resistance.5,24 This is consistent with the results of Haroun.5 He found that RI is sensitive in 64% of cases of complete obstruction and in 33% of cases of partial obstruction. DeToledo et al24 found a sensitivity of RI of 91.8% for patients with complete obstruction and 48.1% in patients with partial obstruction with a specificity of 92.8% in respect of the group of normal patients.


Functional evaluation of the urinary tract by duplex Doppler ultrasonography in patients with acute renal colic.

Sayani R, Ali M, Shazlee K, Hamid RS, Hamid K - Int J Nephrol Renovasc Dis (2011)

Subsequent IVU of same patient shows complete obstruction on right side due to a distal ureteral calculus.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3278255&req=5

f4b-ijnrd-5-015: Subsequent IVU of same patient shows complete obstruction on right side due to a distal ureteral calculus.
Mentions: Our study showed that elevation of RI and delta RI was related to the degree of ureteric obstruction. In our study the RI was above the 0.70 threshold in 77.5% of cases of complete urinary obstruction and in 22.8% of cases of partial obstruction. Similarly, delta RI was elevated in 92.5% cases of complete obstruction and in 62.8% cases of partial obstruction (Figures 4A and B). This can be explained by the fact that ureteral pressure in partial obstruction is not sufficiently elevated to induce an increase in renal vascular resistance.5,24 This is consistent with the results of Haroun.5 He found that RI is sensitive in 64% of cases of complete obstruction and in 33% of cases of partial obstruction. DeToledo et al24 found a sensitivity of RI of 91.8% for patients with complete obstruction and 48.1% in patients with partial obstruction with a specificity of 92.8% in respect of the group of normal patients.

Bottom Line: The mean RI for obstructed kidneys was 0.67 (0.048), which was significantly higher (P-value <0.05) than a mean RI of contralateral normal kidneys 0.59 (0.04).The mean delta RI in patients with unilateral ureteric obstruction was significantly higher than that in patients with normal kidneys, at 0.076 (0.03) and 0.03 (0.05), respectively.However, due to relatively low sensitivity for detection of partial obstruction, DDU cannot replace IVU as the standard imaging technique.

View Article: PubMed Central - PubMed

Affiliation: Radiology Department, Aga Khan University Hospital, Karachi, Pakistan.

ABSTRACT

Purpose: To determine the role of duplex Doppler ultrasonography (DDU) in patients with acute unilateral renal obstruction.

Subjects and methods: A total of 161 patients with suspected renal colic due to urolithiasis were evaluated by DDU followed by intravenous urography (IVU). The mean intra-arterial resistive index (RI) and the difference of mean resistive index between both kidneys (delta RI) were determined for each person. An RI value of ≥0.70 and a delta RI value of ≥0.06 were taken as the discriminatory threshold for obstruction. IVU results were considered the " reference standard" against which renal DDU findings were compared.

Results: IVU showed both kidneys to be normal in 51 patients and with unilateral ureteric obstruction in 110 patients. The mean RI for obstructed kidneys was 0.67 (0.048), which was significantly higher (P-value <0.05) than a mean RI of contralateral normal kidneys 0.59 (0.04). The mean delta RI in patients with unilateral ureteric obstruction was significantly higher than that in patients with normal kidneys, at 0.076 (0.03) and 0.03 (0.05), respectively. In patients with complete obstruction, sensitivity of RI and delta RI were 77.5% and 92.5% with a specificity of 84.3% and 90.1%, respectively. In patients with partial obstruction, the sensitivity of these values was 22.8% and 62.8% with a specificity of 84.3% and 90.1%.

Conclusion: Delta RI is more sensitive and specific than RI in acute renal obstruction. However, due to relatively low sensitivity for detection of partial obstruction, DDU cannot replace IVU as the standard imaging technique.

No MeSH data available.


Related in: MedlinePlus