Flexible array coil for cervical and extraspinal (FACE) MRI at 3.0 Tesla

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Device Engineering
• Radiology

Background:

• High-resolution cervical spine (c-spine) and extraspinal neck MRI requires receiver coils that closely fit the patient for optimal signal-to-noise ratio (SNR).
• Conventional rigid c-spine coils do not conform well to individual neck anatomy, leading to reduced SNR.
• Flexible, conformable coil arrays offer potential for improved SNR and higher acceleration factors in 3D MRI.

Purpose of the Study:

• To design, implement, and evaluate a novel, conformal 23-channel flexible receive-only array for cervical and extraspinal (FACE) MRI at 3 Tesla (T).
• To assess the performance of the FACE array in terms of SNR and parallel imaging capabilities compared to a conventional head-neck-unit (HNU) coil.
• To evaluate the clinical utility of the FACE array for high-resolution c-spine and neck MRI, including MR neurography (MRN).

Main Methods:

• A 23-channel conformal, flexible receive-only array (FACE) with high-impedance elements was designed for 3T MRI.
• Coil performance was evaluated using phantom studies measuring SNR and geometry factors (g-factors) against a conventional 21-channel HNU coil.
• In vivo imaging was conducted in healthy volunteers and patients using high-resolution c-spine and neck MRI protocols at 3T.

Main Results:

• The FACE array demonstrated significantly higher mean SNR (141%-161%) at off-isocenter positions and 4% at isocenter in phantom studies compared to the HNU.
• Parallel imaging performance showed comparable results at R = 2x2, but improved g-factors (1.46-2.15) for R = 3x3 with the FACE array versus the HNU (2.36-3.62).
• Preliminary in vivo testing confirmed equivalent or superior image quality for cervical osseous and soft tissue evaluation using the FACE array.

Conclusions:

• A conformal, highly flexible cervical MRI array with high-impedance elements can significantly enhance SNR.
• This novel coil design improves parallel imaging performance, enabling higher acceleration factors for cervical imaging.
• The FACE array holds potential for enabling higher-resolution cervical MRI, improving diagnostic capabilities.