Technical Developments: Zero Echo Time Imaging of the Shoulder: Enhanced Osseous Detail by Using MR Imaging

Area of Science:

• Orthopedic imaging
• Radiology
• Medical physics

Background:

• Computed tomography (CT) is standard for osseous shoulder imaging.
• Magnetic resonance (MR) imaging offers soft-tissue detail but limited bone visualization.
• Zero echo time (ZTE) MR imaging aims to improve bone contrast.

Purpose of the Study:

• To assess intermodality agreement between CT and ZTE MR imaging for shoulder osseous morphology and measurements.
• To evaluate the clinical applicability of ZTE MR imaging in shoulder bone assessment.
• To compare the visualization of osseous features between ZTE MR and standard-of-care (SOC) MR imaging.

Main Methods:

• Thirty-four patients with concomitant CT and MR imaging of the shoulder were studied.
• ZTE MR images were acquired post-SOC MR imaging.
• Morphologic grading and quantitative measurements of glenoid and osseous lesions were performed using CT and ZTE MR.
• Statistical analysis included kappa values, intraclass correlation coefficients (ICCs), and Bland-Altman limits of agreement.

Main Results:

• Substantial to excellent agreement (κ or ICC > 0.6) was observed for binary and ordinal osseous classifications between CT and ZTE MR.
• Continuous measurements showed strong correlation, though not universally significant.
• ZTE MR imaging demonstrated superior conspicuity of enthesopathic cysts and marrow edema.
• In 62% (21/34) of cases, ZTE MR imaging provided better visualization of osseous features than SOC MR imaging.

Conclusions:

• ZTE MR imaging provides "CT-like" contrast for bone, enabling detailed osseous assessment.
• Strong quantitative agreement between CT and ZTE MR imaging supports its clinical utility.
• ZTE MR imaging may serve as a viable alternative to CT for specific shoulder osseous evaluations.
• Superior visualization of osseous features suggests ZTE MR imaging enhances diagnostic capabilities.