Occurrence and value of the color Doppler "line sign" after radiofrequency ablation of solid abdominal organs.
OBJECTIVE
The purposes of this study were to identify the frequency of the color "line sign" after track coagulation during electrode removal and to evaluate the usefulness of color Doppler sonography in predicting complications after radiofrequency ablation.


METHODS
A total of 104 consecution radiofrequency ablations of either the liver (n = 68) or the kidney (n = 36) were evaluated for hemorrhagic complications by color Doppler sonography. All radiofrequency ablations were performed in a similar fashion, including track coagulation during electrode removal. Follow-up computed tomography of the organ of interest was performed within 24-hours after the procedure.


RESULTS
The study included 32 patients with 36 renal radiofrequency ablations and 43 patients with 68 hepatic ablations. There were 1 arterial and 0 venous Doppler signals in the renal ablations and 2 arterial and 2 venous Doppler signals in the hepatic ablations. No major complications were observed, but a moderate hematoma occurred in 1 renal ablation. A statistically significant correlation was noted between the computed tomographic findings of hematomas and the presence of a color line sign (P = .048). We found a lower percentage of the color line sign compared to prior reports that identified this sign after biopsy of the liver or kidney.


CONCLUSIONS
There is a decreased frequency of the color line sign and hemorrhagic complications after radiofrequency ablation compared to their rates of occurrence with core biopsy. Identification of the color line sign may be useful for predicting hemorrhagic complications.
Department of Radiology, University of California, Davis Medical Center, Sacramento, CA 95817, USA. john.mcgahan@ucdmc.ucdavis.edu
John P
JP
McGahan
Luke
L
Wright
John
J
Brock
D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation / Q000379:methods*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol; D007674:Kidney Diseases / Q000000981:diagnostic imaging* / Q000601:surgery*; D008107:Liver Diseases / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color; D018084:Ultrasonography, Interventional
D003287:Contrast Media; D007472:Iohexol