Intravoxel incoherent motion diffusion-weighted imaging in diagnosing perineural invasion status of rectal cancer: a histogram analysis study

Motivation: Currently, perineural invasion (PNI) of rectal cancer (RC) can only be confirmed by pathological examination of postoperative specimens. Goal(s): It aimed to investigate the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in diagnosing the PNI status of RC by histogram analysis. Approach: We extracted histogram features from 7 parametric maps derived from IVIM-DWI. The independent predictive histogram features of rectal cancer PNI were combined with the percentage of rectal wall enclosure（PCI ) reported by MRI to construct a combined model for preoperative diagnosis of PNI. Results: The AUC of the combined model is higher than that of each single-parameter model and histogram model. Impact: This study demonstrated that full-volume histogram parameters basing on IVIM-DWI can be used to assess PNI status in rectal cancer. Histogram analysis, as a non-invasive tool, may be more valuable not only in rectal cancer research in the future.