7-T MRI intratumoral susceptibility signals reflect biomarker status in gliomas.

OBJECTIVE

To evaluate whether 7-T susceptibility-weighted imaging (SWI) can predict glioma's histological grade, Ki-67 labeling index (LI), isocitrate dehydrogenase 1 (IDH1) mutation, 1p/19q co-deletion, telomerase reverse transcriptase (TERT) promoter mutation, and O-6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation status of gliomas.

MATERIALS AND

METHODS

We retrospectively analyzed 7-T SWI in 60 patients with glioma. The Mann-Whitney U test compared the intratumoral susceptibility signals (ITSS) grade across molecular markers, with ITSS defined as fine linear or dot-like low signal areas on SWI. Predictive efficacy was assessed using receiver operating characteristic (ROC) analysis and multivariate logistic regression models. Path analysis evaluated the relationships between ITSS grade and molecular markers.

RESULTS

Gliomas with high ITSS grade showed higher histological grade, Ki-67 LI, and TERT mutation rates compared to those with low ITSS grade, mostly being wild-type gliomas. ITSS grade predicted the histological grade, Ki-67 LI, and TERT status (area under the ROC curve = 0.769‒0.817). Multivariate logistic regression analysis identified Ki-67 LI and TERT status as independent predictors of high ITSS grade. Path analysis indicated direct effects of Ki-67 LI and TERT mutation on ITSS grade, and an indirect effect of IDH1 mutation on ITSS grade mediated through Ki-67 LI.

CONCLUSION

7-T SWI-derived ITSS grade predicts histologic grade, Ki-67 LI, and TERT promoter mutation status in gliomas. Ki-67 LI and TERT mutation exert relatively independent effects on ITSS grade and allow reverse inference of their status from SWI, whereas IDH1 mutation influences ITSS grade indirectly via Ki-67 LI.

RELEVANCE STATEMENT: This study establishes a connection between preoperative imaging and molecular glioma pathology via 7-T SWI. It helps to reveal the in vivo characteristics of pathology and promotes collaboration among radiologists, pathologists, and clinicians, which a great clinical potential.

KEY POINTS: A 7-T susceptibility-weighted MRI-based intratumoral susceptibility signal (ITSS) grading system enables precise detection of glioma microbleeds and neovascularization. 7-T susceptibility-weighted MRI-derived ITSS grade noninvasively predicts histologic grade, Ki-67 labeling index, and telomerase reverse transcriptase (TERT) promoter mutation status in gliomas. Path analysis suggested that molecular markers relate to ITSS grade through distinct pathways, with Ki-67 and TERT exerting direct effects and isocitrate dehydrogenase 1 influencing ITSS grade indirectly.