RSNA 2003 

Abstract Archives of the RSNA, 2003


M05-1105

Sonographic Detection of Renal and Ureteral Calculi: Diagnostic Accuracy of the Twinkle Sign

Scientific Papers

Presented on December 3, 2003
Presented as part of M05: Genitourinary (Genitourinary Imaging: Urinary Tract Calculi)

Participants

Andrea Klauser MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: To compare the detection of urinary stones using gray-scale ultrasound (US) to the accuracy of diagnosis using the color Doppler (CD) twinkle sign. Methods and Materials: 41 patients with at least one urinary stone on unenhanced CT. were evaluated with US and CD. The likelihood of a stone was rated sonographically at 8 locations within each kidney/ureter - intrarenal upper-pole, intrarenal mid-pole, intrarenal lower-pole, renal pelvis, uretero-pelvic junction (UPJ), mid ureter, distal ureter and uretero-vesicle junction (UVJ). Each location was rated on a 5 point scale (1- definitely negative; 5- definitely positive). Comparison of US and CD diagnosis was performed with a clustered receiver operating characteristic (ROC) analysis. Results: 77 stones were present in 41 subjects, including intrarenal (n=47), renal pelvis (n=5), UPJ (n=8), ureter (n=5) and UVJ (n=12) stones. Based upon US, the diagnosis of stone was made with confidence in 66% (51/77) and with CD twinkle in 97% (75/77). Ten false positive stones were suggested within an intrarenal location in 10 subjects, while 1 false positive stone was suggested at a UPJ. One of the false positive intrarenal stones was suggested only by the Doppler twinkle sign. Clustered ROC analysis demonstrated that the Doppler twinkle sign (Az = 0.99) was significantly better than conventional gray scale criteria (Az = 0.95) for the diagnosis of urinary stones (p = 0.005). Conclusion: The CD twinkle sign improves the detection and confidence of diagnosis for urinary calculi with minimal loss of specificity. Overall diagnostic accuracy is significantly improved by the addition of CD.       Questions about this event email: andrea.klauser@uibk.ac.at

Cite This Abstract

Klauser MD, A, Sonographic Detection of Renal and Ureteral Calculi: Diagnostic Accuracy of the Twinkle Sign.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3103292.html