title: Cardiac helical CT involving a low-radiation-dose protocol with a 100-kVp setting: Usefulness of hybrid iterative reconstruction and display preset optimization.
abstract: To compare the radiation dose and image quality of retrospective electrocardiogram (ECG)-gated cardiac computed tomography (CT) between a 100-kVp protocol, hybrid iterative reconstruction (HIR), and display preset optimization and the 120-kVp protocol.We prospectively enrolled 100 patients with tachycardia or atrial fibrillation scanned retrospective ECG-gated cardiac CT. We randomly assigned 50 patients to the 120-kVp protocol and 50 patients to the 100-kVp protocol. We compared effective doses (EDs) between the two protocols. The 120-kVp images were post-processed using filtered back projection (FBP). The 100-kVp images were post-processed using FBP (100-kVp protocol) and HIR (i-100-kVp protocol). We compared attenuation of the ascending aorta, signal-to-noise ratio (SNR), and image noise between the 120-kVp, 100-kVp, and i-100-kVp protocols. We performed qualitative image analysis for the 120-kVp and i-100-kVp protocols.ED of the 100-kVp protocol (4.4 ± 0.4 mSv) was 76% lower than that of the 120-kVp protocol (18.4 ± 0.6 mSv). Attenuations of the 100-kVp (549.1 ± 73.8 HU) and i-100-kVp (550.5 ± 73.7 HU) protocols were higher than that of the120-kVp protocol (437.3 ± 55.7 HU). Image noise of the 100-kVp (53.6 ± 18.5 HU) and i-100-kVp (30.9 ± 8.6 HU) protocols were higher than that of the120-kVp protocol (23.8 ± 5.7 HU). There was no significant difference in SNR and the result of qualitative image analysis between the 120-kVp and i-100-kVp protocols.The 100-kVp protocol with HIR reduced the 76% radiation dose while preserving the image quality compared with the conventional 120-kVp protocol on retrospective ECG-gated cardiac CT.
authors.affiliation: Diagnostic Radiology, Kumamoto chuo hospital Department of Diagnostic Radiology, Graduate School of Medical, Kumamoto University Diagnostic Radiology, Amakusa Medical Center, Amakusa, Kumamoto, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Iyama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakaura
authors.forename: Koichi
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kidoh
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis*; D057186:Comparative Effectiveness Research; D000072226:Computed Tomography Angiography / Q000295:instrumentation / Q000379:methods; D003287:Contrast Media / Q000494:pharmacology; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007479:Iopamidol / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D011829:Radiation Dosage; D012815:Signal Processing, Computer-Assisted; D013610:Tachycardia / Q000175:diagnosis*; D036542:Tomography, Spiral Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007479:Iopamidol