RATIONALE AND OBJECTIVES:To investigate the clinical value of time-dependent diffusion MRI(Td-dMRI) for predicting IDH and 1p/19q codeletion status in adult-type diffuse gliomas.
MATERIALS AND METHODS:174 patients with diffuse glioma who underwent preoperative Td-dMRI and diffusion-weighted imaging (DWI) between June 2022 and September 2024 were prospectively enrolled. Td-dMRI-based parameters, including Diameter, Vin, Cellularity, and three apparent diffusion coefficients were quantified. DWI-derived ADCtumor and normalized ADCratio were computed. The differences in Td-dMRI and DWI-derived-parameters between the different IDH and 1p/19q type gliomas were analyzed using t-tests and ANOVA followed by Bonferroni comparisons. Diagnostic performance was evaluated using the receiver operating characteristic curve (ROC) and the Delong test was used to compare the differences. Logistic regression model was constructed, with its performance evaluated using ROC curve, calibration curves, and the Hosmer-Lemeshow test. The correlation between histologically quantified and Td-dMRI-based parameters was assessed using Spearman's correlation.
RESULTS:IDH wild-type gliomas exhibited smaller Diameter, higher Vin and higher Cellularity than IDH mutant-type gliomas. Vin yielded an AUC of 0.851 (95%CI:0.786-0.916), slightly higher than those of ADCtumor (AUC = 0.777, 95%CI: 0.703-0.851) and ADCratio (AUC = 0.786, 95%CI: 0.714-0.858). Among IDH mutant-type glioma, 1p/19q codeleted glioma showed higher Vin and lower Diameter than non-codeleted glioma. Combined Diameter, Vin and Cellularity achieved the best performance (AUC = 0.908, 95%CI:0.836-0.979), while DWI failed to identify 1p19q genotypes. The Td-dMRI estimated parameters correlated well with the pathologic measurements (r = 0.78-0.79, p<0.001).
CONCLUSION:Td-dMRI is an effective method for predicting IDH and 1p/19q codeletion subtypes in adult-type diffuse gliomas.