Ultra-short and zero echo time MRI sequences for MSK investigation: A scoping review

Area of Science:

• Musculoskeletal Imaging
• Radiology
• Medical Physics

Background:

• Magnetic resonance imaging (MRI) struggles with cortical bone visualization due to low proton density and short decay times.
• Ultrashort echo time (UTE) and zero echo time (ZTE) sequences offer radiation-free alternatives for bone imaging.
• This review identifies key technical parameters, benefits, and drawbacks of UTE and ZTE in musculoskeletal (MSK) imaging.

Purpose of the Study:

• To review the technical parameters, advantages, and limitations of UTE and ZTE sequences for MSK imaging.
• To assess the potential of UTE and ZTE for visualizing cortical bone and improving fracture detection.
• To synthesize current evidence on the application of UTE and ZTE in MSK MRI.

Main Methods:

• Systematic literature search of MEDLINE, EMBASE, and CINAHL databases (post-2005).
• Inclusion of French and English articles using keywords related to UTE, ZTE, MRI, and MSK.
• Screening of titles, abstracts, and full texts by two independent reviewers, with consensus for disagreements.

Main Results:

• Eighteen articles met the inclusion criteria, focusing on spine, lower limb, head/neck, general bone, and shoulder imaging.
• UTE and ZTE utilize radial acquisition with very short echo times (0.00-0.34 ms) and varying repetition times (0.425-1075 ms).
• These sequences provide enhanced cortical bone signal and fracture contrast, comparable to CT, with acquisition times of 3-12 minutes; acquisition time was a noted disadvantage.

Conclusions:

• UTE and ZTE sequences are effective for MSK applications, providing good contrast for cortical bone evaluation.
• These radiation-free techniques can improve fracture assessment in MSK MRI.
• Future research should explore AI for enhancing image quality and reducing UTE/ZTE acquisition times.