PURPOSE: We aimed to compare the radiation dose and image quality of a minimal phase window centered at 77 % compared with a wide phase window in coronary CT angiography using the second-generation 320-row CT. MATERIALS AND METHODS: Eighty patients with heart rate ≤75 bpm were retrospectively included. The first 40 patients underwent scanning with a wide phase window (65-85 %), while the last 40 patients underwent scanning with a minimal phase window centered at 77 %. Subjective image quality was graded using a 4-point scale (4 = excellent). Image noise and contrast-to-noise ratio at the proximal segments were also analyzed. The mean effective dose was derived from the dose length product multiplied by a chest conversion coefficient (κ = 0.014 mSv mGy(-1) cm(-1)). RESULTS: Minimal phase window scanning centered at 77 % reduced the radiation dose by 30 % compared with wide phase window scanning (1.7 vs 2.4 mSv, p = 0.0009). The subjective image quality showed no significant difference (3.75 vs 3.76, p = 0.77). No significant difference was observed in the image noise, CT number, and contrast-to-noise ratio. CONCLUSIONS: Radiation dose could be reduced while maintaining image quality by use of a minimal phase window centered at 77 % compared with a wide phase window in coronary CT angiography using the second generation 320-row CT.
PURPOSE: We aimed to compare the radiation dose and image quality of a minimal phase window centered at 77 % compared with a wide phase window in coronary CT angiography using the second-generation 320-row CT. MATERIALS AND METHODS: Eighty patients with heart rate ≤75 bpm were retrospectively included. The first 40 patients underwent scanning with a wide phase window (65-85 %), while the last 40 patients underwent scanning with a minimal phase window centered at 77 %. Subjective image quality was graded using a 4-point scale (4 = excellent). Image noise and contrast-to-noise ratio at the proximal segments were also analyzed. The mean effective dose was derived from the dose length product multiplied by a chest conversion coefficient (κ = 0.014 mSv mGy(-1) cm(-1)). RESULTS: Minimal phase window scanning centered at 77 % reduced the radiation dose by 30 % compared with wide phase window scanning (1.7 vs 2.4 mSv, p = 0.0009). The subjective image quality showed no significant difference (3.75 vs 3.76, p = 0.77). No significant difference was observed in the image noise, CT number, and contrast-to-noise ratio. CONCLUSIONS: Radiation dose could be reduced while maintaining image quality by use of a minimal phase window centered at 77 % compared with a wide phase window in coronary CT angiography using the second generation 320-row CT.
Authors: Arash Bedayat; Frank J Rybicki; Kanako Kumamaru; Sara L Powers; Jason Signorelli; Michael L Steigner; Chloe Steveson; Shigeyoshi Soga; Kimberly Adams; Dimitrios Mitsouras; Melvin Clouse; Richard T Mather Journal: Int J Cardiovasc Imaging Date: 2011-02-19 Impact factor: 2.357
Authors: Michael L Steigner; Hansel J Otero; Tianxi Cai; Dimitrios Mitsouras; Leelakrishna Nallamshetty; Amanda G Whitmore; Hale Ersoy; Noah A Levit; Marcelo F Di Carli; Frank J Rybicki Journal: Int J Cardiovasc Imaging Date: 2008-07-29 Impact factor: 2.357
Authors: Marcus Y Chen; Michael L Steigner; Steve W Leung; Kanako K Kumamaru; Kurt Schultz; Richard T Mather; Andrew E Arai; Frank J Rybicki Journal: Int J Cardiovasc Imaging Date: 2013-02-13 Impact factor: 2.357