Reducing PNS with minimal performance penalties via simple pulse sequence modifications on a high-performance compact...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Biophysics

Background:

• High-performance MRI gradients can cause peripheral nerve stimulation (PNS).
• A compact 3 T MRI system with advanced gradients (80 mT/m amplitude, 700 T/m/s slew rate) was evaluated for PNS.
• Most pulse sequences showed minimal or no PNS due to smaller gradient coil dimensions.

Purpose of the Study:

• To investigate the incidence of PNS in subjects scanned with high-performance gradients.
• To evaluate the effectiveness of targeted pulse sequence modification for mitigating PNS.
• To assess the impact of modification on image quality and scan time.

Main Methods:

• Scanned over 680 subjects on a 3 T MRI system with high-performance gradients.
• Identified a specific 3D fast spin echo (3DFLAIR) sequence causing PNS in ~2% of subjects.
• Modified the problematic gradient lobes of the 3DFLAIR sequence and re-scanned affected subjects.

Main Results:

• PNS was rarely reported, with only 5 out of 252 subjects experiencing it with the 3DFLAIR sequence.
• Targeted modification of the 3DFLAIR sequence successfully eliminated PNS in re-scanned subjects.
• Image quality and scan time remained largely unaffected by the pulse sequence modification.

Conclusions:

• PNS is infrequent even with high-performance gradients on a compact 3 T MRI system.
• Targeted gradient waveform modification is an effective strategy for managing sequence-specific PNS.
• This approach avoids system-wide performance derating, preserving overall MRI capabilities.