Simultaneous acquisition of perfusion and permeability from corrected relaxation rates with dynamic susceptibility contrast dual gradient echo.
This study compared two methods, corrected (separation of T(1) and T(2)* effects) and uncorrected, in order to determine the suitability of the perfusion and permeability measures through Delta R(2)* and Delta R(1) analyses. A dynamic susceptibility contrast dual gradient echo (DSC-DGE) was used to image the fixed phantoms and flow phantoms (Sephadex perfusion phantoms and dialyzer phantom for the permeability measurements). The results confirmed that the corrected relaxation rate was linearly proportional to gadolinium-diethyltriamine pentaacetic acid (Gd-DTPA) concentration, whereas the uncorrected relaxation rate did not in the fixed phantom and simulation experiments. For the perfusion measurements, it was found that the correction process was necessary not only for the Delta R(1) time curve but also for the Delta R(2)* time curve analyses. Perfusion could not be measured without correcting the Delta R(2)* time curve. The water volume, which was expressed as the perfusion amount, was found to be closer to the theoretical value when using the corrected Delta R(1) curve in the calculations. However, this may occur in the low concentration of Gd-DTPA in tissue used in this study. For the permeability measurements based on the two-compartment model, the permeability factor (k(ev); e = extravascular, v = vascular) from the outside to the inside of the hollow fibers was greater in the corrected Delta R(1) method than in the uncorrected Delta R(1) method. The differences between the corrected and the uncorrected Delta R(1) values were confirmed by the simulation experiments. In conclusion, this study proposes that the correction for the relaxation rates, Delta R(2)* and Delta R(1), is indispensable in making accurate perfusion and permeability measurements, and that DSC-DGE is a useful method for obtaining information on perfusion and permeability, simultaneously.
Kim
Eun-Ju
EJ
Department of Diagnostic Radiology, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 134 Sinchon, Seodaemun Seoul 120-752, South Korea.
Kim
Dae-Hong
DH
Lee
Sang Hoon
SH
Huh
Yong-Min
YM
Song
Ho-Taek
HT
Suh
Jin-Suck
JS
D000465:Algorithms; D001808:Blood Vessels / Q000378:metabolism; D001810:Blood Volume; D003287:Contrast Media / Q000737:chemistry* / Q000493:pharmacokinetics; D005119:Extravasation of Diagnostic and Therapeutic Materials; D019786:Gadolinium DTPA / Q000737:chemistry* / Q000493:pharmacokinetics; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008954:Models, Biological; D010477:Perfusion; D010539:Permeability; D019047:Phantoms, Imaging
D003287:Contrast Media; D019786:Gadolinium DTPA