title: Achieving consistent image quality with dose optimization in 64-row multidetector computed tomography prospective ECG gated coronary calcium scoring.
abstract: To evaluate the clinical value of a body mass index (BMI) based tube current (mA) selection method for obtaining consistent image quality with dose optimization in MDCT prospective ECG gated coronary calcium scoring. A formula for selecting mA to achieve desired image quality based on patient BMI was established using a control group (A) of 200 MDCT cardiac patients with a standard scan protocol. One hundred patients in Group B were scanned with this BMI-dependent mA for achieving a desired noise level of 18 HU at 2.5 mm slice thickness. The CTDIvol and image noise on the ascending aorta for the two groups were recorded. Two experienced radiologists quantitatively evaluated the image quality using scores of 1-4 with 4 being the highest. The image quality scores had no statistical difference (P = 0.71) at 3.89 ± 0.32, 3.87 ± 0.34, respectively, for groups A and B of similar BMI. The image noise in Group A had linear relationship with BMI. The image noise in Group B using BMI-dependent mA was independent of BMI with average value of 17.9 HU and smaller deviations for the noise values than in Group A (2.0 vs. 2.9 HU). There was a 35% dose reduction with BMI-dependent mA selection method on average with the lowest effective dose being only 0.35 mSv for patient with BMI of 18.3. A quantitative BMI-based mA selection method in MDCT prospective ECG gated coronary calcium scoring has been proposed to obtain a desired and consistent image quality and provide dose optimization across patient population.
authors.affiliation: Department of Radiology, School of Medicine, Shanghai Ruijin Hospital affiliated to Jiaotong University, 197 Ruijin Er Road, 200025 Shanghai, China.
authors.forename: Zilai
authors.initials: Z
authors.lastname: Pan
authors.forename: Lifang
authors.initials: L
authors.lastname: Pang
authors.forename: Jianying
authors.initials: J
authors.lastname: Li
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.forename: Wenjie
authors.initials: W
authors.lastname: Yang
authors.forename: Bei
authors.initials: B
authors.lastname: Ding
authors.forename: Weimin
authors.initials: W
authors.lastname: Chai
authors.forename: Kemin
authors.initials: K
authors.lastname: Chen
authors.forename: Weiwu
authors.initials: W
authors.lastname: Yao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002114:Calcinosis / Q000000981:diagnostic imaging*; D055424:Cardiac-Gated Imaging Techniques; D002681:China; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed