Exploring diagnostic performance of T2 mapping in diffuse glioma grading.

Area of Science:

• Radiology
• Neuro-oncology
• Medical Imaging

Background:

• Accurate glioma grading is crucial for treatment planning and prognosis.
• Differentiating World Health Organization (WHO) grade II gliomas from high-grade gliomas (HGG) can be challenging with conventional imaging.
• T2 mapping offers quantitative magnetic resonance imaging (MRI) data that may aid in glioma characterization.

Purpose of the Study:

• To evaluate the diagnostic performance of T2 mapping in differentiating WHO grade II glioma from HGG.
• To assess the accuracy of T2 relaxation time in predicting isocitrate dehydrogenase (IDH) status.

Main Methods:

• A retrospective diagnostic study included 159 patients with confirmed diffuse glioma (WHO grade II-IV).
• T2 mapping, T1-weighted imaging, and T2-weighted imaging were performed.
• Receiver operating characteristic (ROC) curves and area under the curve (AUC) were generated using subsampled data for T2 mapping and multivariable analysis (including age, T2 relaxation time, and contrast enhancement).

Main Results:

• T2 mapping achieved an average AUC of approximately 0.801 for differentiating WHO grade II glioma from HGG, with an average sensitivity of 0.753 and specificity of 0.767.
• Multivariable analysis incorporating T2 relaxation time, age, and contrast enhancement yielded a higher AUC of 0.927.
• T2 relaxation times significantly differed between IDH-mutant and IDH-wildtype gliomas (146.28 ms vs. 124.10 ms, P=0.001), with an AUC of 0.687 for IDH-mutant prediction.

Conclusions:

• Quantitative T2 mapping demonstrates moderate sensitivity and specificity in differentiating WHO grade II glioma from HGG.
• The technique is feasible for pre-operative glioma grading due to its short acquisition time and lack of contrast agent requirement.
• T2 mapping provides valuable quantitative information that can aid in glioma classification and potentially predict IDH status.