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| Twinkling Artifact on Color Doppler Ultrasound: Comparison among Various Composition of Stones and Various Central Frequencies of Transducers |
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| Chul Ho Sohn, M.D. Jeong Hyun Lee, M.D.*, Kyoung Sik Cho, M.D.* |
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| Department of Radiology, Keimyung University School of Medicine *Department of Radiology, University of Ulsan College of Medicine Asan Medical Center |
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| PURPOSE : To evaluate the relationship between the degree of twinkling artifact generated on color Doppler sonography
and the biochemical composition of renal stones and different central frequencies of transducers.
MATERIALS and METHODS : Three types of renal stones (A = 90% calcium oxalate + 10% calcium hydrogen phosphate,
B = 50% calcium oxalate + 5% calcium hydrogen phosphate + 45% ammonium urate, and C = 55% urate
+ 35% calcium oxalate + 5% ammonium urater + 5% calcium hydrogen phosphate) removed from the subjects
and one artificially made plastic-ball (D) were examined in vitro with color Doppler ultrasonography. Four
transducers (C4-5, C7-4, L7-4, L10-5MHz) were used. All stones were placed in a depth of between 3 and 4 cm
in an agar plate. Grading of twinkling artifact was done: 0 = absent, 1 = present but occupying less than half of a
stone, 3 = occupying the entire stone and 2 = between 1 and 3. Color Doppler gain was set to the point just below
the threshold for color noise. Each artifact was graded by two independent observers, and if there was interobserver
difference, the consensus was reached.
RESULTS : The size of stones ranged from 6 to 10mm (mean = 8mm). Type A stone produced grade 1 artifact on C4-
2, grade 2 on C7-4 and grade 3 on L7-4 and L10-5. Type B stone produced grade 1 artifact on all transducers;
type C stone produced grade 0 artifact on C4-2, grade 2 on C7-4, and grade 1 on L7-4, and L10-5. The plastic
ball produced grade 1 artifact on L10-5, and grade 0 on other transducers.
CONCLUSION : Different grades of twinkling artifact on color Doppler ultrasonography were evoked depending on
the biochemical composition of renal stones and different central frequencies of transducers. The major limitation
of our study was that the number of the subjects were smal. |
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| Keyword : Ultrasound (US), artifact Ultrasound (US), Doppler studies Genitourinary system, calculi |
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pdf파일 : 213-218손철호.pdf 
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> Journal > Journal Search 
Journal of Korean Society of Ultrasound in Medicine 2002 ; 21 (3) : p.213-218
