Anzeige
Erschienen in:
01.08.2012 | Computed Tomography
Model-based iterative reconstruction technique for radiation dose reduction in chest CT: comparison with the adaptive statistical iterative reconstruction technique
Erschienen in: European Radiology | Ausgabe 8/2012
Einloggen, um Zugang zu erhaltenAbstract
Objectives
To prospectively evaluate dose reduction and image quality characteristics of chest CT reconstructed with model-based iterative reconstruction (MBIR) compared with adaptive statistical iterative reconstruction (ASIR).
Methods
One hundred patients underwent reference-dose and low-dose unenhanced chest CT with 64-row multidetector CT. Images were reconstructed with 50 % ASIR-filtered back projection blending (ASIR50) for reference-dose CT, and with ASIR50 and MBIR for low-dose CT. Two radiologists assessed the images in a blinded manner for subjective image noise, artefacts and diagnostic acceptability. Objective image noise was measured in the lung parenchyma. Data were analysed using the sign test and pair-wise Student’s t-test.
Results
Compared with reference-dose CT, there was a 79.0 % decrease in dose–length product with low-dose CT. Low-dose MBIR images had significantly lower objective image noise (16.93 ± 3.00) than low-dose ASIR (49.24 ± 9.11, P < 0.01) and reference-dose ASIR images (24.93 ± 4.65, P < 0.01). Low-dose MBIR images were all diagnostically acceptable. Unique features of low-dose MBIR images included motion artefacts and pixellated blotchy appearances, which did not adversely affect diagnostic acceptability.
Conclusion
Diagnostically acceptable chest CT images acquired with nearly 80 % less radiation can be obtained using MBIR. MBIR shows greater potential than ASIR for providing diagnostically acceptable low-dose CT images without severely compromising image quality.
Key Points
• Model-based iterative reconstruction (MBIR) creates high-quality low-dose CT images.
• MBIR significantly improves image noise and artefacts over adaptive statistical iterative techniques.
• MBIR shows greater potential than ASIR for diagnostically acceptable low-dose CT.
• The prolonged processing time of MBIR may currently limit its routine use in clinical practice.