Article Figures & Data
Figures
- Fig 1.
Right frontal anaplastic oligoastrocytoma (WHO grade III) in a 43-year-old man. A dynamic series of ssT1 SPGR images through one anatomic location before, during, and after the administration of intravenous Gd-DTPA demonstrate earlier enhancement of normal vessels followed by delayed and persistent enhancement of the right frontal high-grade glioma.
- Fig 2.
Left cavernous sinus hemangiopericytoma in a 30-year-old woman. A dynamic series of ssT1 SPGR images through multiple anatomic locations before (top row), during (middle 2 rows), and after (bottom row) the administration of intravenous Gd-DTPA demonstrate simultaneous contrast agent arrival within the normal vessels (second row, horizontal arrows) and within this highly vascular extra-axial brain tumor (slanted arrow).
- Fig 3.
Left thalamic/posterior frontal GBM (WHO grade IV) in a 63-year-old man. Upper panel, Left, Transaxial contrast-enhanced SPGR image demonstrates an enhancing left dorsolateral thalamic and posterior frontal lobe tumor (arrow). Middle and Right, Transaxial T2-weighted image (middle) and FLAIR (right) show moderate degree of surrounding edema (arrowheads). Lower panel, Left, Transaxial ssT1 Ktrans map demonstrates a rim of increased permeability (arrow). Middle, Transaxial fpT2* Ktrans color map overlayed onto SPGR image also shows a rim of increased permeability. Right, Transaxial fpT2* rCBV color map overlayed onto SPGR image demonstrates similar rim shape of increased blood volume but more focused on the medial aspect of the tumor (arrow).
- Fig 4.
Right frontal anaplastic oligoastrocytoma (WHO grade III) in a 43-year-old man. Upper panel, Left, Transaxial contrast-enhanced SPGR image demonstrates a large heterogeneously right frontal lobe tumor. Middle and Right, Transaxial T2-weighted image (middle) and FLAIR (right) show moderate degree of surrounding edema. Lower panel, Left, Transaxial ssT1 Ktrans map demonstrates a large central area of increased permeability. Middle, Transaxial fpT2* Ktrans color map overlayed onto SPGR image also shows global increase in permeability throughout the tumor. Right, Transaxial fpT2* rCBV color map overlayed onto SPGR image demonstrates increased blood volume mostly involving the medial aspect of the tumor.
- Fig 5.
Box plots of fpT2* rCBV maximum, ssT1- and fpT2*-derived Ktrans values (in minutes−1) for grades I, II, III, and IV gliomas. Box plots of fpT2* rCBV maximum, ssT1- and fpT2*-derived Ktrans values (in minutes−1) for grades I, II, III, and IV gliomas. The red box extends from the first quartile to the third quartile of the data, with the white line marking the median. The black lines with end brackets represent the most extreme observations in the data that are not more than 1.5 times the height of the box beyond either quartile. All points outside this range are presented by a circle and are considered to be outliers. There was only one patient with grade I gliomas (pilocytic astrocytoma), and the value was presented as horizontal [I] bar in the plots.
- Fig 6.
Scatter plots and fitted regression line of ssT1-derived Ktrans on fpT2*-derived Ktrans. The Pearson correlation coefficient for gliomas is high and estimated to be 0.95 (95% CI [0.89, 0.98]); however, no linear correlation exists between fpT2* and ssT1 Ktrans values for meningiomas, with the Pearson correlation coefficient estimated to be 0.16 (95% CI [−0.68, 0.81]).
Tables
- Table 1:
Comparison between the ssT1 and fpT2* methods: theoretical and practical considerations
ssT1 Method fpT2* Method Theoretical considerations Shape of contrast agent concentration time curve Bi-exponential decay Gamma-variate Concentration of intravascular contrast agent Lower Higher Ktrans for normal brain tissue Zero Negligible or very small, but not zero Rate of contrast agent movement from intravascular to extravascular space within a single voxel of tissue Slower Faster Practical considerations Spatial resolution Higher Lower Subjectivity to susceptibility artifact No Yes Imaging time Longer (>6 min) Shorter (<1.5 min) Postprocessing algorithm complexity Higher Lower - Table 2:
P values from the Kruskal-Wallis test of overall equality of all three grades for rCBV max, ssT1-, and fpT2*-derived Ktrans
rCBV max ssT1-Derived Ktrans fpT2*-Derived Ktrans Kruskal-Wallis test .03* .006* .003* Grade II vs III .11 >.5 >0.5 Grade II vs IV .019 .017 .005† Grade III vs IV .19 .009† .002† * For significant Kruskal-Wallis test, P values from 3 Wilcoxon rank sum tests for 2 sample data were listed with Bonferroni adjustment for multiple comparisons.
† Difference was statistically significant after Bonferroni adjustment for multiple comparisons
