Assessment of Correlation between Intravoxel Incoherent Motion Diffusion Weighted MR Imaging and Dynamic Contrast-Enhanced MR Imaging of Sacroiliitis with Ankylosing Spondylitis

Abstract EN

The relationships between IVIM and DCE-MRI parameters in AS are not clear.

We explore the correlation between intravoxel incoherent motion (IVIM) diffusion weighted imaging (DWI) and dynamic contrast-enhanced (DCE) parameters obtained on MR images in patients with ankylosing spondylitis (AS).

Forty-four patients with AS were prospectively examined using a 1.5-T MR system.

IVIM DWI was performed with 11 b values (range, 0–800 s/mm2) for all patients.

The correlation coefficients between IVIM and DCE-MRI parameters were analyzed using Spearman’s method.

Our results showed that intra- and interobserver reproducibility were excellent to relatively good (ICC = 0.804–0.981; narrow width of 95% limits of agreement).

Moderate positive correlations were observed between pure molecular diffusion (Ds) and maximum enhancement (ME) and relative enhancement (RE) (r = 0.700, P<0.001; r=0.607, P < 0.001, resp.).

Perfusion-related diffusion (Df) showed negative moderate correlation with ME (r = -0.608, P < 0.001).

However, no correlation was observed between perfusion fraction (f) and any parameters of ME, RE, TTP, and BE (r = −0.093–0.213; P > 0.165).

In conclusion, the IVIM parameters, especially f, might play a critical role in detecting the progression of AS, because it can provide more perfusion information compared with DCE-MRI; besides the IVIM MRI is a noninvasive method.