Seitaro Oda1, Daisuke Utsunomiya2, Yoshinori Funama3, Kazuhiro Katahira4, Keiichi Honda4, Shinichi Tokuyasu5, Mani Vembar6, Hideaki Yuki2, Katsuo Noda7, Shuichi Oshima7, Yasuyuki Yamashita2. 1. Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan. Electronic address: seisei0430@nifty.com. 2. Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan. 3. Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan. 4. Department of Diagnostic Radiology, Kumamoto Chuo Hospital, Kumamoto, Japan. 5. CT Clinical Science, Philips Electronics Japan, Minato-ku, Tokyo, Japan. 6. CT Clinical Science, Philips Healthcare, Cleveland, OH. 7. Department of Cardiology, Kumamoto Chuo Hospital, Kumamoto, Japan.
Abstract
RATIONALE AND OBJECTIVES: To investigate whether "full" iterative reconstruction, a knowledge-based iterative model reconstruction (IMR), enables radiation dose reduction by 80% at cardiac computed tomography (CT). MATERIALS AND METHODS: A total of 23 patients (15 men, eight women; mean age 64.3 ± 13.4 years) who underwent retrospectively electrocardiography-gated cardiac CT with dose modulation were evaluated. We compared full-dose (FD; 730 mAs) images reconstructed with filtered back projection (FBP) technique and the low-dose (LD; 146 mAs) images reconstructed with FBP and IMR techniques. Objective and subjective image quality parameters were compared among the three different CT images. RESULTS: There was no significant difference in the CT attenuation among the three reconstructions. The mean image noise of LD-IMR (18.3 ± 10.6 Hounsfield units [HU]) was significantly lowest among the three reconstructions (41.9 ± 15.3 HU for FD-FBP and 109.9 ± 42.6 HU for LD-FBP; P < .01). The contrast-to-noise ratio of LD-IMR was better than that of FD-FBP and LD-FBP (P < .01). Visual evaluation score was also highest for LD-IMR. CONCLUSIONS: The IMR can provide improved image quality at super-low-dose cardiac CT with 20% of the standard tube current.
RATIONALE AND OBJECTIVES: To investigate whether "full" iterative reconstruction, a knowledge-based iterative model reconstruction (IMR), enables radiation dose reduction by 80% at cardiac computed tomography (CT). MATERIALS AND METHODS: A total of 23 patients (15 men, eight women; mean age 64.3 ± 13.4 years) who underwent retrospectively electrocardiography-gated cardiac CT with dose modulation were evaluated. We compared full-dose (FD; 730 mAs) images reconstructed with filtered back projection (FBP) technique and the low-dose (LD; 146 mAs) images reconstructed with FBP and IMR techniques. Objective and subjective image quality parameters were compared among the three different CT images. RESULTS: There was no significant difference in the CT attenuation among the three reconstructions. The mean image noise of LD-IMR (18.3 ± 10.6 Hounsfield units [HU]) was significantly lowest among the three reconstructions (41.9 ± 15.3 HU for FD-FBP and 109.9 ± 42.6 HU for LD-FBP; P < .01). The contrast-to-noise ratio of LD-IMR was better than that of FD-FBP and LD-FBP (P < .01). Visual evaluation score was also highest for LD-IMR. CONCLUSIONS: The IMR can provide improved image quality at super-low-dose cardiac CT with 20% of the standard tube current.
Authors: Brendan L Eck; Rachid Fahmi; Kevin M Brown; Stanislav Zabic; Nilgoun Raihani; Jun Miao; David L Wilson Journal: Med Phys Date: 2015-10 Impact factor: 4.071
Authors: Bálint Szilveszter; Hesham Elzomor; Mihály Károlyi; Márton Kolossváry; Rolf Raaijmakers; Kálmán Benke; Csilla Celeng; Andrea Bartykowszki; Zsolt Bagyura; Árpád Lux; Béla Merkely; Pál Maurovich-Horvat Journal: Int J Cardiovasc Imaging Date: 2015-08-19 Impact factor: 2.357