Method for Automatic Tube Current Selection for Obtaining a Consistent Image Quality and Dose Optimization in a Cardiac Multidetector CT.
10.3348/kjr.2009.10.6.568
- Author:
Weiwei QI
1
;
Jianying LI
;
Xiangke DU
Author Information
1. Department of Radiology, Peking University People's Hospital, China. cyanage8@gmail.com
- Publication Type:Original Article
- Keywords:
Computed tomography (CT);
Coronary artery imaging;
Consistent image quality;
Dose reduction and optimization;
Automatic tube current modulation
- MeSH:
Female;
Heart Diseases/*radiography;
Humans;
Male;
Mathematics;
Middle Aged;
Radiation Dosage;
Radiographic Image Interpretation, Computer-Assisted;
Retrospective Studies;
Tomography, X-Ray Computed/*instrumentation
- From:Korean Journal of Radiology
2009;10(6):568-574
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: To evaluate a quantitative method for individually adjusting the tube current to obtain images with consistent noise in electrocardiogram (ECG)-gated CT cardiac scans. MATERIALS AND METHODS: The image noise from timing bolus and cardiac CT scans of 80 patients (Group A) who underwent a 64-row multidetector (MD) CT cardiac examination with patient-independent scan parameters were analyzed. A formula was established using the noise correlation between the timing bolus and cardiac scans. This formula was used to predict the required tube current to obtain the desired cardiac CT image noise based on the timing bolus noise measurement. Subsequently, 80 additional cardiac patients (Group B) were scanned with individually adjusted tube currents using an established formula to evaluate its ability to obtain accurate and consistent image noise across the patient population. Image quality was evaluated using score scale of 1 to 5 with a score of 3 or higher being clinically acceptable. RESULTS: Using the formula, we obtained an average CT image noise of 28.55 Hounsfield unit (HU), with a standard deviation of only 1.7 HU, as opposed to a target value of 28 HU. Image quality scores were 4.03 and 4.27 for images in Groups A and B, respectively, and there was no statistical difference between the image quality scores between the two groups. However, the average CT dose index (CTDIvol) was 30% lower for Group B. CONCLUSION: Adjusting the tube current based on timing bolus scans may provide a consistent image quality and dose optimization for cardiac patients of various body mass index values.
