Assessment of sacroiliitis using zero echo time magnetic resonance imaging: a comprehensive evaluation

Area of Science:

• Radiology
• Orthopedics
• Rheumatology

Background:

• Enthesitis-related arthritis (ERA), a subtype of juvenile idiopathic arthritis (JIA), frequently affects the sacroiliac (SI) joints.
• Conventional MRI sequences often have limitations in visualizing osseous and calcified tissues within the SI joints.

Purpose of the Study:

• To evaluate the efficacy of zero echo time (ZTE) magnetic resonance imaging (MRI) for identifying structural lesions in patients with ERA.
• To compare the diagnostic performance of ZTE-MRI against low-dose computed tomography (CT) for SI joint abnormalities.

Main Methods:

• Utilized a 1.5-T MRI scanner with standard sequences and an additional ZTE sequence.
• Included low-dose CT as the reference standard for comparison.
• Assessed structural lesions such as erosions, sclerosis, and joint space changes.

Main Results:

• ZTE-MRI demonstrated comparable sensitivity to low-dose CT in detecting erosions.
• Achieved excellent interclass correlation coefficients (ICCs) for agreement with low-dose CT in identifying sclerosis (ICC=0.954) and joint space changes (ICC=0.998).
• The interclass correlation coefficient between low-dose CT and ZTE-MRI was 0.993 for overall agreement.

Conclusions:

• ZTE imaging offers promising visualization of sacroiliac joints, comparable to low-dose CT.
• This technique enhances the detection of subtle erosions and sclerosis in the SI joints of ERA patients.