1naresh<pre>Array
(
    [urn:ac.highwire.org:guest:identity] => Array
        (
            [runtime-id] => urn:ac.highwire.org:guest:identity
            [type] => guest
            [service-id] => ajnr-ac.highwire.org
            [access-type] => Controlled
            [privilege] => Array
                (
                    [urn:ac.highwire.org:guest:privilege] => Array
                        (
                            [runtime-id] => urn:ac.highwire.org:guest:privilege
                            [type] => privilege-set
                            [privilege-set] => GUEST
                        )

                )

            [credentials] => Array
                (
                    [method] => guest
                )

        )

)
1naresh<pre>Array
(
    [urn:ac.highwire.org:guest:identity] => Array
        (
            [runtime-id] => urn:ac.highwire.org:guest:identity
            [type] => guest
            [service-id] => ajnr-ac.highwire.org
            [access-type] => FreeToRead
            [privilege] => Array
                (
                    [urn:ac.highwire.org:guest:privilege] => Array
                        (
                            [runtime-id] => urn:ac.highwire.org:guest:privilege
                            [type] => privilege-set
                            [privilege-set] => GUEST
                        )

                )

            [credentials] => Array
                (
                    [method] => guest
                )

        )

)
PT  - JOURNAL ARTICLE
AU  - Cha, S.
AU  - Yang, L.
AU  - Johnson, G.
AU  - Lai, A.
AU  - Chen, M.-H.
AU  - Tihan, T.
AU  - Wendland, M.
AU  - Dillon, W.P.
TI  - Comparison of Microvascular Permeability Measurements, K&lt;sup&gt;trans&lt;/sup&gt;, Determined with Conventional Steady-State T1-Weighted and First-Pass T2*-Weighted MR Imaging Methods in Gliomas and Meningiomas
DP  - 2006 Feb 01
TA  - American Journal of Neuroradiology
PG  - 409--417
VI  - 27
IP  - 2
4099  - http://www.ajnr.org/content/27/2/409.short
4100  - http://www.ajnr.org/content/27/2/409.full
SO  - Am. J. Neuroradiol.2006 Feb 01; 27
AB  - BACKGROUND AND PURPOSE: The widely accepted MR method for quantitating brain tumor microvascular permeability, Ktrans, is the steady-state T1-weighted gradient-echo method (ssT1). Recently the first-pass T2*-weighted (fpT2*) method has been used to derive both relative cerebral blood volume (rCBV) and Ktrans. We hypothesized that Ktrans derived from the ssT1 and the fpT2* methods will correlate differently in gliomas and meningiomas because of the unique differences in morphologic and functional status of each tumor vascular network.METHODS: Before surgery, 27 patients with newly diagnosed gliomas (WHO grade I–IV; n = 20) or meningiomas (n = 7) underwent conventional anatomic MR imaging and 12 dynamic ssT1 acquisitions followed by 60 dynamic fpT2* images before and after gadopentate dimeglumine administration. The 3 hemodynamic variables—fpT2* rCBV, fpT2* Ktrans, and ssT1 Ktrans—were calculated in anatomically identical locations and correlated with glioma grade. The fpT2* Ktrans values were compared with ssT1 Ktrans for gliomas and meningiomas.RESULTS: All 3 hemodynamic variables displayed distinct distributions among grades 2, 3, and 4 gliomas by using the Kruskal-Wallis test. Only Ktrans values, and not rCBV, could differentiate between grade 4 and lower-grade gliomas by using the Wilcoxon rank sum test. The fpT2* Ktrans was highly predictive of ssT1 Ktrans for gliomas, with an estimated regression coefficient of 0.49 (P &amp;lt; .001). For meningiomas, however, fpT2* Ktrans values correlated poorly with ssT1 Ktrans values (r = 0.26; P = .74).CONCLUSION: Compared with rCBV, Ktrans values derived from either ssT1 or fpT2* were more predictive of glioma grade. The fpT2* Ktrans was highly correlated with ssT1 Ktrans in gliomas but not in meningiomas.