Iterative Reconstructions in Reduced-Dose CT

Abstract

Reduced-dose CT during the follow-up of young oncology patients should be reconstructed with MBIR to ensure diagnostic quality. Elevated body mass index does not hamper the quality of reduced-dose CT.

Influence of Acquisition Time on MR Image Quality Estimated with Nonparametric Measures Based on Texture Features

“…To our knowledge, there are very few previous studies that have attempted to introduce nonparametric models for the successful quality estimation of MR images. The majority of previous studies focus on the complexity of quality analysis in different postprocessing modalities used in computed tomography (CT) associated with the use of postprocessing algorithms, such as SAFIRE, ADMIRE (Siemens), and ASiR (GE) [13, 36, 47, 48]. Woodard and Carley-Spencer [49] evaluated nonparametric measures of MR image quality, implementing an analysis of variance (ANOVA) to demonstrate the variation in different quality grades.…”

Iterative Reconstruction: State-of-the-Art and Future Perspectives

“…Alongside, IR preserves CT attenuation values and maintains high image quality and diagnostic confidence when compared with FBP. 4,[7][8][9][10]12,13,20,21 Moreover, IR has allowed to obtain high-quality CT images while maintaining low the radiation dose also in obese patients or those with large body habitus and has permitted to perform ultra-LD (ULD) CT in patients with urolithiasis. 22 Furthermore, IR algorithms allow up to 70% of dose reduction compared with FBP while maintaining comparable image quality in high-contrast resolution scenarios (eg, lung parenchymal evaluation).…”

“…Besides, the main strength of IR methods lies in the actual correlation between simulated data with the measured raw data, which leads to an effective reduction of image noise and artifacts, and relative fast reconstruction time. Alongside, IR preserves CT attenuation values and maintains high image quality and diagnostic confidence when compared with FBP 4,7–10,12,13,20,21 . Moreover, IR has allowed to obtain high-quality CT images while maintaining low the radiation dose also in obese patients or those with large body habitus and has permitted to perform ultra-LD (ULD) CT in patients with urolithiasis 22 …”

“…On the other hand, high-strength IR does not perform well in low-contrast tasks (eg, small hypoattenuating liver metastasis), resulting in lower diagnostic accuracy. In such cases, however, a dose reduction of 10% to 27% can still be reached 12 . Nevertheless, high-strength IR data sets are usually not preferred by radiologists, because of relatively slow reconstruction time and their impact on image texture, leading to oversmoothened “plasticlike” images potentially hampering clinical tasks 7,8,19 …”

“…8,10 In fact, CT scans acquired at low radiation dose and reconstructed with FBP result in a significant deterioration of image quality, including noisy images, poor low-contrast detectability, and artifacts secondary to photon starvation (eg, streaking). Therefore, FBP offers negligible dose reduction potential with the risk of compromising diagnostic image quality [7][8][9]12 ; as such, it has been replaced by IR algorithms. 13,14…”