Application of keyhole imaging to interventional MRI: a simulation study to predict sequence requirements

Area of Science:

• Medical Imaging
• Magnetic Resonance Imaging
• Interventional Radiology

Background:

• Improving temporal resolution in MRI is critical for dynamic procedures.
• Keyhole imaging offers a simple approach using conventional MRI techniques.
• Interventional MRI (I-MRI) demands high temporal and spatial resolution for accurate guidance.

Purpose of the Study:

• To investigate optimal phase-encoding ordering and data-sharing for keyhole imaging in I-MRI.
• To evaluate the feasibility of keyhole imaging for needle tip localization during I-MRI.

Main Methods:

• A simulation study was conducted to analyze different keyhole imaging acquisition strategies.
• Phase-encoding order and k-space data sharing were systematically varied.
• The impact on temporal and spatial resolution for needle localization was assessed.

Main Results:

• Conventional keyhole methods focusing only on central k-space data are insufficient for I-MRI.
• Sequential k-space acquisition from the center outward also fails to meet I-MRI resolution requirements.
• Acquiring both high and low k-space data in a ranked order shows promise for I-MRI.

Conclusions:

• Standard keyhole imaging protocols are inadequate for precise needle tip localization in I-MRI.
• A novel keyhole acquisition strategy, prioritizing high and low k-space data, is proposed for I-MRI.
• This optimized approach could enable accurate real-time guidance for I-MRI procedures.