title: [Optimal scan timing in 64-row MDCT angiography of the lower extremities: 2-point ROI detection bolus-tracking method].
abstract: In CT angiography of the lower extremities, we have developed a 2-point ROI detection bolus-tracking method (2ROI-BTM) to provide the optimal contrast medium concentration and reduce contrast medium. The time to reach the ankle from the abdominal aorta was 22.5 s (95% central range, 14.6-40.1 s). The mean scan time was 13.6 s (range, 11.5-15.0 s). In the 2ROI-BTM (n=78), the mean CT number was 516 HU in the aorta, 427 HU in the popliteal artery, and 323 HU in the tibial artery. Compared with the TIM (n=66), the CT number was low in only 3% or less of cases, and the usual contrast medium dose of 20 ml for test injection could be reduced. With the 2ROI-BTM, the optimal scan timing can be determined more easily than with the TIM, allowing the contrast medium dose to be reduced by 26% and providing contrast enhancement with superior reproducibility of morphological characteristics for the generation of 3D images.
authors.affiliation: Department of Radiology, Maiduru Kyosai Hospital.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Kitai
authors.forename: Takasi
authors.initials: T
authors.lastname: Haraguchi
mesh_terms: D000792:Angiography / Q000379:methods*; D001012:Aorta, Abdominal; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging; D001783:Blood Flow Velocity; D003287:Contrast Media / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D006801:Humans; D021621:Imaging, Three-Dimensional; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011150:Popliteal Artery; D015203:Reproducibility of Results; D016909:Tibial Arteries; D013997:Time Factors; D036542:Tomography, Spiral Computed / Q000379:methods*
chemical_list: D003287:Contrast Media