Computed diffusion-weighted imaging for differentiating synovial proliferation from joint effusion in hand arthritis

Area of Science:

• Radiology
• Medical Imaging
• Rheumatology

Background:

• Differentiating synovial proliferation from joint effusion is crucial for diagnosing and managing rheumatoid arthritis (RA).
• Contrast-enhanced MRI is commonly used but carries risks and costs.
• Computed diffusion-weighted imaging (cDWI) offers a potential non-contrast alternative.

Purpose of the Study:

• To evaluate computed diffusion-weighted imaging (cDWI) as a non-contrast method for differentiating synovial proliferation from joint effusion.
• To compare cDWI with measured DWI (mDWI) and apparent diffusion coefficient (ADC) values.
• To assess the diagnostic performance of cDWI in patients with suspected RA.

Main Methods:

• Nine patients with suspected RA underwent MRI, including STIR, mDWI, and synthesized cDWI.
• Regions of interest (ROIs) were graded for synovial proliferation by a radiologist.
• cDWI was synthesized at various b-values; contrast ratios and ADC values were calculated.

Main Results:

• cDWI synthesized with b-values of 400-1000 s/mm² (cDWI₂₀₀₀) showed significant correlation with radiologist's grading of synovial proliferation (r=0.405, p<0.01).
• The area under the curve for cDWI₂₀₀₀ (0.762) was superior to ADC values (0.570-0.608) in differentiating enhancement grades.
• cDWI₁₈₀₀ and cDWI₂₀₀₀ demonstrated high sensitivity (84.6%) and specificity (66.7%) in visual assessment.

Conclusions:

• Computed diffusion-weighted imaging (cDWI), particularly cDWI₂₀₀₀ (400-1000 s/mm²), shows potential for non-invasively differentiating synovial proliferation from joint effusion in hand arthritis.
• cDWI may serve as a valuable alternative to contrast-enhanced MRI, reducing risks and improving diagnostic efficiency.
• Further research with larger cohorts is warranted to validate these findings.