Seitaro Oda1, Gaby Weissman2, Mani Vembar3, Wm Guy Weigold4. 1. Department of Cardiology, MedStar Washington Hospital Center, 110 Irving Street, NW, Washington, DC 20010, United States; 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 Cardiology, MedStar Washington Hospital Center, 110 Irving Street, NW, Washington, DC 20010, United States. Electronic address: Gaby.Weissman@medstar.net. 3. CT Clinical Science, Philips Healthcare, c595 Miner Road, Cleveland, OH 44143, United States. Electronic address: mani.vembar@philips.com. 4. Department of Cardiology, MedStar Washington Hospital Center, 110 Irving Street, NW, Washington, DC 20010, United States. Electronic address: Guy.Weigold@MedStar.net.
Abstract
OBJECTIVES: To investigate the effects of a new model-based type of iterative reconstruction (M-IR) technique, the iterative model reconstruction, on image quality of prospectively gated coronary CT angiography (CTA) acquired at low-tube-voltage. METHODS: Thirty patients (16 men, 14 women; mean age 52.2 ± 13.2 years) underwent coronary CTA at 100-kVp on a 256-slice CT. Paired image sets were created using 3 types of reconstruction, i.e. filtered back projection (FBP), a hybrid type of iterative reconstruction (H-IR), and M-IR. Quantitative parameters including CT-attenuation, image noise, and contrast-to-noise ratio (CNR) were measured. The visual image quality, i.e. graininess, beam-hardening, vessel sharpness, and overall image quality, was scored on a 5-point scale. Lastly, coronary artery segments were evaluated using a 4-point scale to investigate the assessability of each segment. RESULTS: There was no significant difference in coronary arterial CT attenuation among the 3 reconstruction methods. The mean image noise of FBP, H-IR, and M-IR images was 29.3 ± 9.6, 19.3 ± 6.9, and 12.9 ± 3.3 HU, respectively, there were significant differences for all comparison combinations among the 3 methods (p<0.01). The CNR of M-IR was significantly better than of FBP and H-IR images (13.5 ± 5.0 [FBP], 20.9 ± 8.9 [H-IR] and 39.3 ± 13.9 [M-IR]; p<0.01). The visual scores were significantly higher for M-IR than the other images (p<0.01), and 95.3% of the coronary segments imaged with M-IR were of assessable quality compared with 76.7% of FBP- and 86.9% of H-IR images. CONCLUSIONS: M-IR can provide significantly improved qualitative and quantitative image quality in prospectively gated coronary CTA using a low-tube-voltage.
OBJECTIVES: To investigate the effects of a new model-based type of iterative reconstruction (M-IR) technique, the iterative model reconstruction, on image quality of prospectively gated coronary CT angiography (CTA) acquired at low-tube-voltage. METHODS: Thirty patients (16 men, 14 women; mean age 52.2 ± 13.2 years) underwent coronary CTA at 100-kVp on a 256-slice CT. Paired image sets were created using 3 types of reconstruction, i.e. filtered back projection (FBP), a hybrid type of iterative reconstruction (H-IR), and M-IR. Quantitative parameters including CT-attenuation, image noise, and contrast-to-noise ratio (CNR) were measured. The visual image quality, i.e. graininess, beam-hardening, vessel sharpness, and overall image quality, was scored on a 5-point scale. Lastly, coronary artery segments were evaluated using a 4-point scale to investigate the assessability of each segment. RESULTS: There was no significant difference in coronary arterial CT attenuation among the 3 reconstruction methods. The mean image noise of FBP, H-IR, and M-IR images was 29.3 ± 9.6, 19.3 ± 6.9, and 12.9 ± 3.3 HU, respectively, there were significant differences for all comparison combinations among the 3 methods (p<0.01). The CNR of M-IR was significantly better than of FBP and H-IR images (13.5 ± 5.0 [FBP], 20.9 ± 8.9 [H-IR] and 39.3 ± 13.9 [M-IR]; p<0.01). The visual scores were significantly higher for M-IR than the other images (p<0.01), and 95.3% of the coronary segments imaged with M-IR were of assessable quality compared with 76.7% of FBP- and 86.9% of H-IR images. CONCLUSIONS: M-IR can provide significantly improved qualitative and quantitative image quality in prospectively gated coronary CTA using a low-tube-voltage.
Authors: Stefanie Mangold; Julian L Wichmann; U Joseph Schoepf; Sheldon E Litwin; Christian Canstein; Akos Varga-Szemes; Giuseppe Muscogiuri; Stephen R Fuller; Andrew C Stubenrauch; Konstantin Nikolaou; Carlo N De Cecco Journal: Eur Radiol Date: 2015-12-28 Impact factor: 5.315
Authors: Andrew D Choi; Eric S Leifer; Jeannie Yu; Sujata M Shanbhag; Kathie Bronson; Andrew E Arai; Marcus Y Chen Journal: J Cardiovasc Comput Tomogr Date: 2016-07-27
Authors: Stefanie Mangold; Julian L Wichmann; U Joseph Schoepf; Damiano Caruso; Christian Tesche; Daniel H Steinberg; Akos Varga-Szemes; Andrew C Stubenrauch; Richard R Bayer; Matthew Biancalana; Konstantin Nikolaou; Carlo N De Cecco Journal: Eur Radiol Date: 2016-09-28 Impact factor: 5.315