Comparison of sonographic and CT guidance techniques: Does CT fluoroscopy decrease procedure time?

OBJECTIVE. Procedure times for percutaneous biopsies were compared for vari ous guidance techniques including helical CT, CT fluoroscopy, sonography wi th an attached needle guide, and freehand sonography with computer guidance . MATERIALS AND METHODS. Three interventional radiologists experienced in CT- and sonographically guided procedures performed biopsies on a phantom model . The phantom simulated hepatic metastases of various sizes and depths with subcostal or intercostal locations. Lesion sizes were 7, 10, and 20 mm, at 3- and 7-cm depths. Using self-aspirating needles, two passes were perform ed in each lesion. Mean procedure time per biopsy pass was calculated. A tw o-tailed Student's t test was used to compare guidance techniques. RESULTS. Mean procedure time per biopsy pass for the four guidance techniqu es was sonography with a needle guide, 36 +/- 9 sec; sonography with comput er guidance, 43 +/- 10 sec; helical CT, 146 +/- 42 sec; and CT fluoroscopy, 50 +/- 18 sec. CT fluoroscopy required 2.6 +/- 1.0 sec per biopsy. Helical CT required more procedure time than sonography with a needle guide, CT wi th computer guidance, and CT fluoroscopy (p < 0.0001). Sonography with a ne edle guide required less procedure time than sonography with computer guida nce (p < 0.002) and CT fluoroscopy (p = 0.0003). Procedure times for CT flu oroscopy and sonography with computer guidance were not statistically diffe rent (p = 0.06). CT and sonographic guidance were equally effective regardl ess of lesion size, depth, or location. CONCLUSION. Traditional sonographic biopsy techniques are faster and more c ost-effective than traditional CT techniques; however, CT fluoroscopy offer s the localization advantages of CT with improved procedure times.