Comparison of Microvascular Permeability Measurements, K^trans, Determined with Conventional Steady-State T1-Weighted and First-Pass T2*-Weighted MR Imaging Methods in Gliomas and Meningiomas

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).

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 K^trans map demonstrates a rim of increased permeability (arrow). Middle, Transaxial fpT2* K^trans 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).

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 K^trans map demonstrates a large central area of increased permeability. Middle, Transaxial fpT2* K^trans 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.

Box plots of fpT2* rCBV maximum, ssT1- and fpT2*-derived K^trans values (in minutes⁻¹) for grades I, II, III, and IV gliomas. Box plots of fpT2* rCBV maximum, ssT1- and fpT2*-derived K^trans 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.