Article Figures & Data
Figures
- Fig 1.
Representative Ktrans maps from (A) a grade II fibrillary astrocytoma, (B) a grade III anaplastic astrocytoma, and (C) a grade IV glioblastoma multiforme. The white boxes enclose the tumor area in each image. Note that vasculature does not appear in these maps, and Ktrans values in normal brain are insignificant and consistent with noise. The Ktrans values in the grade II tumor (A) are insignificant corresponding to the lack of enhancement with contrast. The high-grade-defining necrotic core is clearly evident in the middle of the tumor in panel C. The heterogeneity of Ktrans is clearly evident in the enhancing tumor portion in panels B and C.
- Fig 2.
Representative CBV maps from (A) a grade II fibrillary astrocytoma, (B) a grade III anaplastic astrocytoma, and (C) a grade IV glioblastoma multiforme. The white boxes enclose the tumor area in each image. The normal cerebral vasculature is clearly seen on these maps, particularly the superior sagittal sinus and other major vessels. The grade II tumor in panel A homogeneously shows very low blood volume, which is below the measurement accuracy of the technique. The necrotic core is clearly evident in the middle of the tumor in panel C. The heterogeneity of CBV is clearly evident in the enhancing tumor portion in panels B and C and shows very different distributions to those in Fig 1 (A and B).
- Fig 3.
Scattergrams showing the relationships between histologic grade and median values of Ktrans, Ktrans (95%), CBV, and CBV (95%). Individual cases are indicated by circles, multiple cases are represented by the addition of “petals” to the glyph with the number of petals representing the number of cases. Lines indicate the optimal linear regression fit for the data and the 95th percentile confidence limits for the regression fit for the entire dataset. The correlation between grade and the median values of each of the parametric variables is significant (Ktrans, Ktrans [95%], CBV, and CBV [95%]; P < .01).
- Fig 4.
Scattergram showing the relationship between values of median CBV and Ktrans (95%) for all individual cases. The grade II tumors show lower values of both CBV and Ktrans (95%). Higher values are seen in grade III and IV tumors, but there is a considerable overlap in these distributions.
- Fig 5.
ROC analysis showing effect of using each individual variable or the discriminant function (C1) in differentiating between high- and low-grade tumors. The area under the ROC curve for high- versus low-grade is greatest for the discriminant function (0.993). Within the independent parametric variables the area was highest for Ktrans (95%) (0.986), though similarly high values were seen for Ktrans and CBV (0.979 and 0.966, respectively). (Areas under the ROC curves are shown in Table 7.)
- Fig 6.
ROC analysis for separation of grade III and IV tumors. Areas under the ROC curves are shown in Table 7.
Tables
Patient No./Sex/Age (y) Histological Grade 1/M/52 IV 2/M/58 IV 3/F/31 II 4/F/46 III 5/M/75 III 6/M/55 IV 7/M/52 IV 8/M/53 III 9/M/53 IV 10/M/45 IV 11/M/54 IV 12/F/71 IV 13/M/64 IV 14/M/69 IV 15/M/69 IV 16/M/50 IV 17/M/55 IV 18/M/65 IV 19/F/56 IV 20/M/47 II* 21/F/46 II* 22/M/44 II* 23/F/34 II* 24/M/45 II 25/F/42 II 26/M/38 III 27/M/46 III 28/M/53 IV 29/M/58 IV 30/M/48 IV 31/F/40 II* 32/F/60 IV 33/M/55 IV 34/M/72 II 35/M/61 IV 36/M/50 IV 37/M/77 IV 38/M/42 III 39/F/33 II Note.—Grading is according to World Health Organisation criteria for histopathologic findings of tissue biopsy samples taken after imaging. In general, glioma grade II indicates fibrillary astrocytoma; III, anaplastic astrocytoma; IV, glioblastoma multiforme.
* Oligodendroglioma, but has been included.
- TABLE 2:
Means and standard deviations of volume transfer coefficient (Ktrans) and cerebral blood volume (CBV) measurements in gliomas grouped by World Health Organization grade
WHO Histological Grade No. of Patients Ktrans (min−1) CBV (%) Mean SD Mean SD Median values* II 10 0.000712 0.000712 1.284 0.75 III 6 0.0185 0.0102 2.995 0.44 IV 23 0.025 0.0177 4.022 1.352 95% values II 10 0.018 0.0126 4.63 2.47 III 6 0.073 0.033 8.83 1.64 IV 23 0.112 0.055 12.24 4.37 Note.—Assumes that values are normally distributed.
Grade III Grade IV Grade II CBV <.001 <.001 Ktrans NS <.001 CBV (95%) <.01 <.001 Ktrans (95%) <.05 <.001 Grade III CBV <.05 Ktrans NS CBV (95%) <.05 Ktrans (95%) NS Note.—CBV indicates cerebral blood volume; Ktrans, volume transfer coefficient. Grading is according to World Health Organization criteria.
- TABLE 4:
Correlation values (Spearman rho) and significance of the correlation between each of the four parameteric variables and grade
Spearman rho Significance CBV 0.719 <.001 Ktrans 0.656 <.001 CBV (95%) 0.718 <.01 Ktrans (95%) 0.740 <.001 Note.—CBV indicates cerebral blood volume; Ktrans, volume transfer coefficient.
Predicted/Observed Grade II Grade III Grade IV Grade II 9 (90) 1 (10) 0 Grade III 0 6 (100) 0 Grade IV 0 9 (39.1) 14 (60.9) Note.—Numbers in parentheses represent percentages of correct classification. The total number of cases correctly classified is 74.4%
C1=0.695 (CBV) + 0.577 (Ktrans (95%)), where CBV indicate cerebral blood volume and Ktrans is the volume transfer coefficient.
- TABLE 6:
Classification results using canonical discriminate functions derived using a leave-one-out (jackknife) cross-validation analysis
Predicted/Observed Grade II Grade III Grade IV Grade II 9 (90) 1 (10) 0 Grade III 1 (16.7) 4 (66.7) 1 (16.7) Grade IV 0 9 (39.1) 14 (60.9) Note.—This approach can be expected to represent classifications more accurately that are expected in a larger population. Numbers in parentheses represent percentages. The number of cases correctly classified is 69.2%.
- TABLE 7:
Results of the receiver operator curve analysis for each variable and for the discriminate function C1 in differentiating between low-grade tumors and grades III IV high-grade tumors
High Versus Low Grade Grade III Versus Grade IV CBV 0.966 (<.001) 0.754 (NS) Ktrans 0.979 (<.05) 0.551 (NS) CBV (95%) 0.955 (<.001) 0.754 (NS) Ktrans (95%) 0.986 (<.001) 0.725 (NS) CI 0.993 (<.001) 0.732 (NS) Note.—CBV indicates cerebral blood volume; Ktrans, volume transfer coefficient. Values are areas under ROC followed by significance (P values) in parentheses.
In this issue
Jump to section
Related Articles
Cited By...
- Automated Processing of Dynamic Contrast-Enhanced MRI: Correlation of Advanced Pharmacokinetic Metrics with Tumor Grade in Pediatric Brain Tumors
- Mitotic Activity in Glioblastoma Correlates with Estimated Extravascular Extracellular Space Derived from Dynamic Contrast-Enhanced MR Imaging
- Dynamic Contrast-Enhanced MR Imaging in Head and Neck Cancer: Techniques and Clinical Applications
- Comparison of the Diagnostic Accuracy of DSC- and Dynamic Contrast-Enhanced MRI in the Preoperative Grading of Astrocytomas
- Pixel-by-Pixel Comparison of Volume Transfer Constant and Estimates of Cerebral Blood Volume from Dynamic Contrast-Enhanced and Dynamic Susceptibility Contrast-Enhanced MR Imaging in High-Grade Gliomas
- Glioma: Application of Histogram Analysis of Pharmacokinetic Parameters from T1-Weighted Dynamic Contrast-Enhanced MR Imaging to Tumor Grading
- Diagnostic Accuracy of Dynamic Contrast-Enhanced MR Imaging Using a Phase-Derived Vascular Input Function in the Preoperative Grading of Gliomas
- Imaging biomarkers of angiogenesis and the microvascular environment in cerebral tumours
- Biology, genetics and imaging of glial cell tumours
- Multimodality Assessment of Brain Tumors and Tumor Recurrence
- Enhancing Fraction in Glioma and Its Relationship to the Tumoral Vascular Microenvironment: A Dynamic Contrast-Enhanced MR Imaging Study
- Enhancing Fraction Predicts Clinical Outcome following First-Line Chemotherapy in Patients with Epithelial Ovarian Carcinoma
- Imaging Tumor Vascular Heterogeneity and Angiogenesis using Dynamic Contrast-Enhanced Magnetic Resonance Imaging