Acceleration of Brain TOF-MRA with Compressed Sensitivity Encoding: A Multicenter Clinical Study.

Area of Science:

• Medical Imaging
• Radiology
• Neuroimaging

Background:

• Three-dimensional time-of-flight MR angiography (3D TOF-MRA) is crucial for brain artery assessment.
• Long scan times have limited the clinical utility of 3D TOF-MRA.
• Fast imaging techniques, including compressed sensitivity encoding (CS), offer potential improvements in speed-quality balance.

Purpose of the Study:

• To evaluate the effectiveness of compressed sensitivity encoding (CS) for accelerating 3D TOF-MRA.
• To determine optimal CS acceleration factors for routine clinical brain TOF-MRA.

Main Methods:

• One hundred subjects underwent 8 brain TOF-MRA sequences: 5 with CS (factors 2-10), 2 with standard SENSE (SF2, SF4), and 1 reference (RS).
• Quantitative (signal intensity, structural similarity, contrast ratio) and qualitative (artery visualization, artifacts, diagnostic confidence) assessments were performed.
• Comparisons were made among all 8 sequences across large, medium, and small arteries.

Main Results:

• Image quality metrics (signal intensity, structural similarity) decreased with increasing CS acceleration factors.
• No significant difference in contrast ratios was found between SF2, CS2, and CS4.
• Acceptable visualization of all arteries was achieved with CS2 and CS4; CS6 showed limitations in small artery visualization; CS8 and CS10 were acceptable for large arteries.

Conclusions:

• Compressed sensitivity encoding factor 4 (CS4) is recommended for routine brain TOF-MRA, balancing image quality and acquisition time.
• CS6 is suitable when small artery visualization is not critical.
• CS10 enables fast visualization of large arteries.