Artifacts at Cardiac MRI: Imaging Appearances and Solutions.

Area of Science:

• Medical Imaging
• Cardiovascular Diseases
• Radiology

Background:

• Cardiac MRI (CMR) is essential for diagnosing cardiovascular diseases.
• CMR image acquisition presents technical challenges, often leading to artifacts.
• Understanding and mitigating these artifacts are critical for diagnostic accuracy.

Purpose of the Study:

• To review common cardiac MRI artifacts.
• To explain the causes of these artifacts.
• To outline strategies for artifact mitigation in various CMR sequences and at 3-T imaging.

Main Methods:

• Review of common CMR sequences including balanced steady-state free precession (bSSFP), cine imaging, late gadolinium enhancement (LGE), phase-contrast imaging, and first-pass perfusion imaging.
• Discussion of artifact types such as band, flow, motion, aliasing, Gibbs ringing, and device-related artifacts.
• Exploration of mitigation techniques including targeted shimming, sequence parameter adjustments, motion compensation, signal averaging, and specialized sequences.

Main Results:

• Balanced steady-state free precession (bSSFP) sequences are prone to band and flow artifacts, exacerbated at 3-T, but manageable with specific techniques.
• Real-time sequences improve cine imaging quality in patients with arrhythmias or poor breath-hold.
• Late gadolinium enhancement (LGE) artifacts can be reduced using single-shot techniques, but partial-volume averaging and incomplete nulling remain challenges.
• Phase-contrast imaging requires careful velocity encoding to avoid aliasing.
• Gibbs ringing in perfusion imaging can be differentiated from true defects.
• Device-related artifacts on LGE images can be mitigated with wide-band sequences.

Conclusions:

• Effective artifact recognition and mitigation are paramount for reliable CMR diagnostics.
• Specific strategies exist to address artifacts in various CMR sequences, including those at higher field strengths like 3-T.
• Adaptation of CMR techniques is necessary to overcome imaging challenges and ensure diagnostic quality.