Clinical Evaluation of Scout Accelerated Motion Estimation and Reduction (SAMER) Motion-Corrected 2D T2-Weighted TSE
Azadeh Hajati1,2, Chen-Hua Chiang1,3, Sittaya Buathong4
1From the Department of Radiology (A.H., C.-H.C., A.T., S.Y., J.M.C., S.Y.H.), Massachusetts General Hospital, Boston, Massachusetts.
Background And Purpose:
Patient motion remains a major source of image degradation in clinical MRI, particularly in acute and inpatient settings. We evaluated the clinical effectiveness of the Scout Accelerated Motion Estimation and Reduction (SAMER) method for retrospective motion correction in axial 2D T2-weighted TSE brain MRI, particularly in emergency and inpatient neurologic settings, where patient motion commonly degrades image quality.
Materials And Methods:
This prospective single-center study included 275 patients undergoing brain MRI on a 3T MRI scanner located in the neurologic intensive care unit between March and September 2024. Each patient received a T2-weighted TSE sequence embedded with the SAMER motion correction framework. Motion artifacts were assessed using 2 approaches in a blinded, randomized fashion: 1) a motion grading scale applied to individual image series before and after SAMER correction by 2 experienced radiologists, and 2) a head-to-head preference test comparing original and motion-corrected images, evaluated by 2 additional neuroradiologists. Statistical analysis included the Wilcoxon signed rank test, intraclass correlation coefficients (ICC), and Cohen kappa agreement scores.
Results:
Motion scores improved significantly after SAMER correction, with average motion grades reduced from 0.79 to 0.62 (Rater 1) and 0.68 to 0.52 (Rater 2) (P < .001 for both). For cases exhibiting at least minimal motion, the improvement was even more pronounced. ICCs were high for both original (0.92) and postcorrection (0.90) ratings, indicating excellent interrater reliability. In the head-to-head comparison, SAMER-corrected images were preferred in 22%-23% of cases, with the original images preferred in fewer than 2%. Cohen kappa showed moderate interrater agreement (κ = 0.61) for motion artifact reduction and fair agreement (κ = 0.39) for overall image quality. A small subset of cases exhibited unexpected results, such as increased motion scores or inhomogeneous correction, suggesting areas for further refinement.
Conclusions:
SAMER significantly reduces motion artifacts in 2D T2-weighted TSE brain MRI performed in the neurologic intensive care unit, improving diagnostic image quality. The method is reliable across multiple raters, integrates seamlessly into clinical workflows, and offers a promising motion correction solution without additional hardware requirements. Further research is warranted to optimize performance under extreme motion conditions and across additional MRI sequences.
Insights
Scout Accelerated Motion Estimation and Reduction (SAMER) significantly reduces motion artifacts in brain MRI, improving image quality for neurologic intensive care unit patients. This method offers a reliable, hardware-free solution for clearer diagnostic imaging.
Area of Science:
- Medical Imaging
- Neurology
- Radiology
Background:
- Patient motion is a significant challenge in clinical MRI, especially in acute and inpatient neurologic settings.
- Motion artifacts degrade image quality, potentially impacting diagnostic accuracy.
- Existing methods for motion correction may be limited in effectiveness or workflow integration.
Purpose of the Study:
- To evaluate the clinical effectiveness of the Scout Accelerated Motion Estimation and Reduction (SAMER) method.
- To assess SAMER's ability to retrospectively correct motion artifacts in axial 2D T2-weighted TSE brain MRI.
- To determine the utility of SAMER in emergency and inpatient neurologic settings.
Main Methods:
- Prospective single-center study with 275 patients on a 3T MRI scanner.
- Utilized a T2-weighted TSE sequence with embedded SAMER motion correction.
- Assessed motion artifacts using a blinded grading scale and head-to-head preference tests by experienced radiologists and neuroradiologists.
Main Results:
- SAMER significantly reduced motion artifact scores (e.g., from 0.79 to 0.62 for Rater 1, P < .001).
- Improvements were more pronounced in cases with initial motion.
- SAMER-corrected images were preferred over original images in 22%-23% of cases, with high interrater reliability (ICC 0.90-0.92).
Conclusions:
- SAMER effectively reduces motion artifacts in brain MRI within neurologic intensive care units.
- The method improves diagnostic image quality and is reliable across raters.
- SAMER offers a promising, hardware-independent motion correction solution for clinical workflows.
