Figure 1.
Flow diagram of patient selection and inclusion and exclusion criteria.
DWI = diffusion-weighted imaging; DSC = dynamic susceptibility contrast; PWI = perfusion-weighted imaging.
Figure 2.
The area under the ROC curve is displayed on the y-axis according to each percentile of the cumulative nCBV histogram on the x-axis.
The 99th percentile value exhibited the highest AUC (0.893) for differentiating high- from low-grade gliomas.
Figure 3.
Images of a 55-year-old male with a grade II astrocytoma.
(A) ROI-drawn rCBV map overlaid on a T2-weighted image, (B) contrast-enhanced T1-weighted image, (C) histogram of nCBV and (D) cumulative nCBV histogram. The 99th percentile value of the cumulative nCBV histogram was 3.703. ROI = region of interest; rCBV = relative CBV; nCBV = normalized CBV.
Figure 4.
Images of a 35-year-old male with a grade III astrocytoma.
(A) ROI-drawn rCBV map overlaid on a T2-weighted image, (B) contrast-enhanced T1-weighted image, (C) histogram of nCBV and (D) cumulative nCBV histogram. The 99th percentile value of the cumulative nCBV histogram was 5.092. ROI = region of interest; rCBV = relative CBV; nCBV = normalized CBV.
Figure 5.
Images of a 50-year-old female with a grade IV glioblastoma.
(A) ROI-drawn rCBV map overlaid on a T2-weighted image, (B) contrast-enhanced T1-weighted image, (C) histogram of nCBV and (D) cumulative nCBV histogram. The 99th percentile value of the cumulative nCBV histogram was 12.489. ROI = region of interest; rCBV = relative CBV; nCBV = normalized CBV.
Table 1.
nCBV histogram parameters of low- and high-grade gliomas.
Table 2.
nCBV histogram parameters of the three different WHO glioma grades.
Table 3.
ROC results for nCBV histogram parameters for glioma grading (low- vs. high-grade).
Table 4.
ROC results for nCBV histogram parameters for glioma grading (Grade III vs. IV).
Figure 6.
Flow diagram explaining the potential grading schema of gliomas using the cumulative nCBV histogram parameter.
The nCBV C99 cutoff value of 4.681 was used to differentiate high- from low-grade gliomas and the nCBV C99 cutoff value of 6.335 was used to identify grade IV gliomas. nCBV = normalized CBV; nCBV C99 = 99th percentile value of nCBV cumulative histogram.
Table 5.
Application of the glioma grading schema to the test set of nine patients.