TY - JOUR
T1 - Limitations of Noncontrast CT for Measuring Ureteral Stones
AU - Van Appledorn, Scott
AU - Ball, Adam J.
AU - Patel, Vipul R.
AU - Kim, Sandy
AU - Leveillee, Raymond J.
PY - 2003/12
Y1 - 2003/12
N2 - Background and Purpose: Patients with renal colic are frequently evaluated in the emergency room with a helical noncontrast CT scan (NCCT) as the primary imaging modality. Treatment decisions are often based on the size of the ureteral stone(s). We wished to assess the accuracy of NCCT in estimating ureteral stone size compared with plain abdominal (KUB) films. Patients and Methods: Forty-eight patients were identified who had ureteral stones seen on NCCT and KUB films performed on the same day. The number of consecutive images on which a ureteral stone was visible on NCCT was multiplied by the reconstruction interval of 5 mm to create a size estimate, which was compared with the measurements of the same stone seen on the KUB film. Results: The NCCT overestimated stone size by approximately 30% to 50% compared with KUB. Conclusion: Counting the number of consecutive NCCT images depicting a ureteral stone is not an accurate method of stone measurement when a reconstruction interval of 5 mm is used. Urologists should consider stone measurement techniques carefully and understand the limitations of imaging studies when evaluating patients with symptomatic ureteral stones.
AB - Background and Purpose: Patients with renal colic are frequently evaluated in the emergency room with a helical noncontrast CT scan (NCCT) as the primary imaging modality. Treatment decisions are often based on the size of the ureteral stone(s). We wished to assess the accuracy of NCCT in estimating ureteral stone size compared with plain abdominal (KUB) films. Patients and Methods: Forty-eight patients were identified who had ureteral stones seen on NCCT and KUB films performed on the same day. The number of consecutive images on which a ureteral stone was visible on NCCT was multiplied by the reconstruction interval of 5 mm to create a size estimate, which was compared with the measurements of the same stone seen on the KUB film. Results: The NCCT overestimated stone size by approximately 30% to 50% compared with KUB. Conclusion: Counting the number of consecutive NCCT images depicting a ureteral stone is not an accurate method of stone measurement when a reconstruction interval of 5 mm is used. Urologists should consider stone measurement techniques carefully and understand the limitations of imaging studies when evaluating patients with symptomatic ureteral stones.
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U2 - 10.1089/089277903772036127
DO - 10.1089/089277903772036127
M3 - Article
C2 - 14744347
AN - SCOPUS:0347356647
VL - 17
SP - 851
EP - 854
JO - Journal of Endourology
JF - Journal of Endourology
SN - 0892-7790
IS - 10
ER -