TY - JOUR
T1 - Detection of uric acid stones in the ureter using low- and conventional-dose computed tomography
AU - Huang, Gene O.
AU - Engebretsen, Steven R.
AU - Smith, Jason C.
AU - Wallner, Caroline L.
AU - Culpepper, David J.
AU - Creech, Jonathan D.
AU - Ng, Caleb C.
AU - Mai, Andrew T.
AU - Chung, Christopher S.
AU - Olgin, Gaudencio
AU - Arnold, Don C.
AU - Baldwin, D. Duane
N1 - Copyright © 2014 Elsevier Inc. All rights reserved.
PY - 2014/9
Y1 - 2014/9
N2 - OBJECTIVE: To determine the ability of low- and conventional-dose computed tomography (CT) in identification of uric acid stones, which are of lower density than calcium oxalate stones.MATERIALS AND METHODS: Uric acid stones (3, 5, and 7 mm) were randomly placed in human cadaveric ureters and scanned using conventional 140-mAs and low-dose 70-, 50-, 30-, 15-, 7.5-, and 5-mAs settings. A single-blinded radiologist reviewed a total of 523 scanned stone images. Sensitivity and specificity were compared among different settings and stone sizes.RESULTS: Imaging using 140-, 70-, 50-, 30-, 15-, 7.5-, and 5-mAs settings resulted in 97%, 97%, 96%, 93%, 83%, 83%, and 69% sensitivity and 92%, 92%, 91%, 89%, 88%, 91%, and 94% specificity, respectively. There was a significant difference in sensitivity between 140 mAs and 15, 7.5, and 5 mAs (P = .011, P = .011, and P <.001, respectively). Sensitivity for 3-, 5-, and 7-mm stones was 83%, 90%, and 93%, respectively. At ≤ 15 mAs, 3-mm stones had a higher rate of false negatives (P <.001).CONCLUSION: Both low- and conventional-dose CTs demonstrate excellent sensitivity and specificity for the detection of ureteral uric acid stones. However, low-dose CT at ≤ 15 mAs resulted in reduced detection of uric acid stones.
AB - OBJECTIVE: To determine the ability of low- and conventional-dose computed tomography (CT) in identification of uric acid stones, which are of lower density than calcium oxalate stones.MATERIALS AND METHODS: Uric acid stones (3, 5, and 7 mm) were randomly placed in human cadaveric ureters and scanned using conventional 140-mAs and low-dose 70-, 50-, 30-, 15-, 7.5-, and 5-mAs settings. A single-blinded radiologist reviewed a total of 523 scanned stone images. Sensitivity and specificity were compared among different settings and stone sizes.RESULTS: Imaging using 140-, 70-, 50-, 30-, 15-, 7.5-, and 5-mAs settings resulted in 97%, 97%, 96%, 93%, 83%, 83%, and 69% sensitivity and 92%, 92%, 91%, 89%, 88%, 91%, and 94% specificity, respectively. There was a significant difference in sensitivity between 140 mAs and 15, 7.5, and 5 mAs (P = .011, P = .011, and P <.001, respectively). Sensitivity for 3-, 5-, and 7-mm stones was 83%, 90%, and 93%, respectively. At ≤ 15 mAs, 3-mm stones had a higher rate of false negatives (P <.001).CONCLUSION: Both low- and conventional-dose CTs demonstrate excellent sensitivity and specificity for the detection of ureteral uric acid stones. However, low-dose CT at ≤ 15 mAs resulted in reduced detection of uric acid stones.
KW - Reproducibility of Results
KW - Calcium Oxalate/chemistry
KW - Humans
KW - Male
KW - Tomography, X-Ray Computed
KW - Image Processing, Computer-Assisted
KW - Uric Acid/analysis
KW - Ureteral Calculi/diagnosis
KW - Sensitivity and Specificity
KW - Female
KW - Ureter/diagnostic imaging
KW - Cadaver
KW - Observer Variation
UR - https://www.scopus.com/pages/publications/84906943603
UR - https://www.scopus.com/pages/publications/84906943603#tab=citedBy
U2 - 10.1016/j.urology.2014.02.021
DO - 10.1016/j.urology.2014.02.021
M3 - Article
C2 - 24746662
SN - 0090-4295
VL - 84
SP - 571
EP - 574
JO - Urology
JF - Urology
IS - 3
ER -