Intravoxel Incoherent Motion Diffusion-Weighted Imaging and 3D-ASL to Assess the Value of Ki-67 Labeling Index and Grade in Glioma

Abstract

Objective. To determine the proportion of intravoxel incoherent motion diffusion-weighted images (IVIM-DWI) and three-dimensional arterial circulation markers (3D-ASL) in Ki-67 labeling index (Ki-67 LI) and glioma grading. Methods. According to the classification of diseases of the central nervous system dealt with by WHO in 2007, patients with stage II glioma were classified as low ( $n=20$ ) and patients with stages III-IV were divided into higher levels ( $n=22$ ). Prior to surgery, brain MRI, IVIM-DWI, and 3D-ASL were performed in all patients, and the actual water molecular diffusion coefficient ( $D$ ), microcirculation coefficient ( $D\ast$ ), blood flow fraction ( $f$ ), and cerebral blood flow (CBF) were measured. A rank sum (Mann–Whitney $U$ test) was used to compare the four upper and lower level Ki-67 LI measurements. Spearman’s method is used to identify the relationship between 4 groups of quantification and Ki-67 LI. Reciprocal grafting (ROC) curves were used to measure the diagnosis of four groups of glioma grading defects. Results. There were significant differences in $D$ , $D\ast$ , $f$ , and CBF between the solid region of the tumor and the normal white matter contralateral to it ( $P<0.05$ ). The significant differences of $rD$ , $rD\ast$ , $rf$ , and $r$ CBF were shown between patients with low-grade glioma and high-grade glioma ( $P<0.05$ ). Ki-67 LI was found to have negative correlation with $rD$ ( $r=00.693$ , $P<0.001$ ) and $rf$ ( $r=00.539$ , $P<0.001$ ), but similarly correlated with $r$ CBF ( $r=0.665$ , $P<0.001$ ) in patients with glioma. Recipient efficacy for predicting advanced and secondary glioma from $rD$ , $rf$ , $rD\ast$ , $r$ CBF, and Ki-67 LI raises AUCs of 0.819, 0.747, 0.719, 0.836, and 0.907, respectively. Conclusion. IVIM-DWI has good application value for preoperative grading of glioma.