Model-based iterative reconstruction for detection of subtle hypoattenuation in early cerebral infarction: a phantom study

作者：Nishizawa Mitsuo^*; Tanaka Hisashi; Watanabe Yoshiyuki; Kunitomi Yuuki; Tsukabe Akio; Tomiyama Noriyuki

来源：Japanese Journal of Radiology, 2015, 33(1): 26-32.

DOI：10.1007/s11604-014-0376-z

• Model-based iterative reconstruction
• Computed tomography
• Dose reduction
• Lesion detectability
• Noise power spectrum

Purpose Model-based iterative reconstruction (MBIR) was recently shown to enable dose reduction in computed tomography (CT). The detectability of low-contrast lesions was assessed on CT images reconstructed with MBIR compared with the conventional filtered back-projection (FBP) method.
Materials and methods A phantom simulating brain gray matter containing small lesions mimicking early cerebral infarctions was scanned at tube currents of 50, 100, 200, and 400 mA. Images were reconstructed by use of both methods. Round regions were cropped from the reconstructed images, half with a lesion, the other half without. Eight radiologists reviewed the images and scored the certainty of lesion detection on a 5-point scale. Overall performance was analyzed by use of a receiver operating characteristic curve.
Results For the tube currents investigated, the analysis showed that the mean areas under the curves for the reviewers were 0.65, 0.70, 0.82, and 0.83 for FBP and 0.70, 0.76, 0.78, and 0.90 for MBIR. For each current, there was no significant difference between the areas under the curves for the different reconstruction methods (p = 0.32, 0.24, 0.49, and 0.17).
Conclusion For the small, low-contrast lesions in the phantom model used in this study, no significant difference between detectability was observed for MBIR and FBP.

• 出版日期2015-1