Liver MRI at 3 T using a respiratory-triggered time-efficient 3D T2-weighted technique: impact on artifacts and image...

Area of Science:

• Radiology
• Medical Imaging
• Magnetic Resonance Imaging

Background:

• Standard 2D T2-weighted turbo spin-echo (TSE) sequences are commonly used for liver MRI at 3 Tesla.
• These sequences can be limited by motion and pulsation artifacts, potentially affecting diagnostic accuracy.
• Developing faster and more robust imaging techniques is crucial for improving liver MRI.

Purpose of the Study:

• To compare the image quality of a novel 3D T2-weighted sequence, Sampling Perfection with Application-optimized Contrasts using Different Flip Angle Evolutions (SPACE), with a standard 2D TSE sequence for liver imaging at 3 T.
• To qualitatively and quantitatively assess artifacts, sharpness, signal-to-noise ratio (SNR), and contrast.

Main Methods:

• A retrospective study involving 20 patients who underwent liver MRI at 3 T.
• T2-weighted breath-hold 2D TSE and respiratory-triggered SPACE sequences were acquired.
• Two radiologists independently assessed image quality, followed by a side-by-side comparison.
• Quantitative analysis included estimated SNR and relative contrast between liver and other tissues.

Main Results:

• The SPACE sequence demonstrated significantly better image quality regarding motion and pulsation artifacts, flow signal suppression, and sharpness of intrahepatic vessels and liver edge.
• Motion and pulsation artifacts were nearly eliminated with the SPACE sequence.
• While estimated liver SNR was not significantly different, the SPACE sequence showed significantly higher relative contrast between the liver and surrounding organs (kidney, gallbladder, spleen).
• SPACE sequence exhibited significantly worse B(1) inhomogeneity artifact and longer scanning times.

Conclusions:

• The respiratory-triggered SPACE sequence offers superior image quality for T2-weighted liver imaging at 3 T, effectively minimizing motion and pulsation artifacts and enhancing tissue contrast.
• Despite advantages, SPACE sequence is associated with increased B(1) inhomogeneity artifact and extended scanning duration compared to 2D TSE.
• SPACE sequence is a promising alternative for liver MRI, balancing improved image quality with considerations for artifact and scan time.