Objective: To investigate the feasibility of tissue similarity map (TSM)-based relative cerebral blood volume (rCBV) assessment in evaluating the hemodynamic characteristics of gliomas and in differentiating high-grade gliomas from low-grade ones without concentration time curve (CTC).
Materials and methods: TSM-based rCBV (rCBV TSM ) and conventional rCBV (rCBV PWI ) maps were generated (n = 35). The differences in percentage and concordance correlation coefficient (CCC) of the rCBV TSM and rCBV PWI ratios were calculated. The Mann-Whitney test and the receiver operating characteristic (ROC) curve analysis were also performed to examine the relationships of rCBV ratios between high- and low-grade gliomas. The improvement factors of signal to noise ratio (SNR) of rCBV TSM maps were also calculated.
Results: The mean difference in percentage between rCBV TSM and rCBV PWI ratios was 4.29 ± 2.62%. The CCC of rCBV TSM and rCBV PWI ratios was 0.9974, with 95% confidence interval of 0.9948, 0.9987, which implied a high agreement between them. The Mann-Whitney test suggested that the rCBV TSM and rCBV PWI ratios of high-grade gliomas were significantly different from those of low-grade gliomas (P < 0.001). The improvement factors of SNR of the rCBV TSM map were 1.31 ± 0.24 for glioma and 1.28 ± 0.24 for normal white matter.
Conclusion: It is feasible to use rCBV TSM in the evaluation of hemodynamic characteristics of gliomas and differentiation of high- and low-grade gliomas without CTC. Moreover, rCBV TSM maps possess a higher SNR, which allows potentially more accurate diagnosis compared with the conventional ones.