Abstract
Purpose: To determine whether radiation doses during computed tomography (CT) colonography (CTC) can be further reduced while maintaining image quality using model-based iterative reconstruction (MBIR). Methods: Twenty patients underwent CTC at a standard dose in supine and prone positions and at a reduced dose in the supine position. All other scan parameters (except noise index) were held constant. Acquisitions were reconstructed using 3 algorithms: filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), and MBIR. Noise was assessed quantitatively by comparing the SD in Hounsfield units at 5 standard locations. Qualitative assessment was made by 2 experienced radiologists blinded to technique who subjectively scored image quality, noise, and sharpness (from 0 to 4). Results: The standard-dose and reduced-dose CT dose index/dose-length product were 6.7/328 and 2.7 mGy/129 mGy-cm, respectively (60 % reduction). Measured mean noise level increased from the standard to the reduced dose (FBP, from 58.6 to 97.2; ASIR from 35.8 to 60.6; and MBIR from 16.6 to 21.9). MBIR had significantly less noise than ASIR on 2-dimensional images at both standard and reduced doses (P < .01). Conclusions: Radiation dose in CTC using MBIR can be reduced by 60 % while maintaining image quality and reducing image noise.
Original language | English (US) |
---|---|
Pages (from-to) | 1183-1189 |
Number of pages | 7 |
Journal | Abdominal Imaging |
Volume | 40 |
Issue number | 5 |
DOIs | |
State | Published - Jun 1 2015 |
Keywords
- Adaptive statistical iterative reconstruction
- CT colonography
- Computed tomography
- Iterative reconstruction
- Model-based iterative reconstruction
- Reduced dose
ASJC Scopus subject areas
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging
- Gastroenterology
- Urology