AJR 2001; 177:875-879
Honda Osamu, Johkoh Takeshi, Tomiyama Noriyuki, Kozuka Takenori, Mihara Naoki, Koyama Mitsuhiro, Hamada Seiki, Naito Hiroaki, Nakamura Hironobu, Judo Masayuki.
OBJECTIVE: The aim of this study was to evaluate the image quality and diagnostic efficacy of multidetector high-resolution CT (HRCT) by comparing it with single-detector HRCT and by comparing the noise ans artifact of multidetector HRCT images with a phantom.
SUBJECTS AND METHODS: Multidetector HRCT with six parameters and single-detector HRCT were performed on cadaveric lungs. The image quality and diagnostic efficacy of multidetector HRCT were evaluated in comparison with those of single-detector HRCT. A phantom was scanned, and image artifact and noise were investigated.
RESULTS: The image quality of multidetector HRCT with axial 1.25 mm ´ 4i (four images per gantry rotation) mode was equal to that of single-detector HRCT. The image quality of multidetector HRCT with other modes was worse than that on single-detector HRCT. The diagnostic efficacy of multidetector HRCT with high-quality mode (pitch, 3:1) and axial mode was equal to that of single-detector HRCT. The diagnostic efficacy on multidetector HRCT with high-speed mode (pitch, 6:1) was worse than that on single-detector HRCT. In the phantom study, images made in high-speed mode had strong artifacts. Noise in the axial mode was milder than that in high-speed mode but more severe than that in high-quality mode.
CONCLUSION: The image quality of axial HRCT with multidetector CT is equal to that on single-detector HRCT. Axial HRCT with multidetector CT is appropriate for evaluating subtle lung abnormalities, but high-speed mode is unsuitable. Using the high-quality mode degrades image quality but is still worthwhile.