SU-G-IeP1-05: Diffusion Kurtosis Imaging for Oropharyngeal Cancer Detection.

PURPOSE: Diffusion kurtosis imaging (DKI) is an emerging diffusion MRI technique in cancer diagnosis applications. The objective of this study is to compare DKI with conventional diffusion weighted imaging (DWI) for diagnosis of head and neck cancer.

METHODS: Five male patients with histologically documented phase II/III squamous cell carcinoma of the oropharynx were included in this study. DKI (with 6 b-values of 0-2000 s/mm2) and conventional DWI data were acquired at a 3.0 T GE MRI scanner. Monoexponential (calculating apparent diffusion coefficient (ADC) using DWI data) and non-Gaussian kurtosis (calculating mean diffusion coefficient (MD) and mean kurtosis coefficient (MK) using DKI data) fits were performed on a voxel-by-voxel basis in selected regions of interest (primary tumor, metastatic nodes, contralateral region of tumor (tongue muscle), and submandibular glands). The non-parametric Wilcoxon test of ADC and DKI parameters between primary tumor and tongue muscle in contralateral region of tumor were calculated for comparison.

RESULTS: Examples of T1 post-contrast images and diffusion parametric maps (ADC, MD and MK) were illustrated in Figure 1 for an oropharynx cancer patient. MK parameters were significantly higher in the primary tumor than in the contralateral tongue muscle (0.89 ± 0.17 vs 0.68 ± 0.13, respectively; P <.05). MD and ADC in the primary tumor were significantly lower than those in the contralateral tongue muscle (1.20 ± 0.23 vs 2.57 ± 1.01; P <0.02 and 0.88 ± 0.22 vs 1.41 ± 0.18; P <0.01, respectively) (Table 1). Figure 2 showed statistical distribution of DWI and DKI parameters in selected regions of interest (primary tumor, metastatic nodes, tongue muscle, and submandibular glands).

CONCLUSION: The preliminary results of this study showed DKI could be a new option for increasing diagnostic confidence of oropharyngeal lesions. We continue to accrue study patients to evaluate the potential correlation between DKI parameters and tumor pathologic factors.