TY - JOUR
T1 - Brain capillary transit time heterogeneity in healthy volunteers measured by dynamic contrast-enhanced T1-weighted perfusion MRI
AU - Larsson, Henrik B.W.
AU - Vestergaard, Mark B.
AU - Lindberg, Ulrich
AU - Iversen, Helle K.
AU - Cramer, Stig P.
PY - 2017/6
Y1 - 2017/6
N2 - Purpose: Capillary transit time heterogeneity, measured as CTH, may set the upper limit for extraction of substances in brain tissue, e.g., oxygen. The purpose of this study was to investigate the feasibility of dynamic contrast-enhanced T1 weighted MRI (DCE-MRI) at 3 Tesla (T), in estimating CTH based on a gamma-variate model of the capillary transit time distribution. In addition, we wanted to investigate if a subtle increase of the blood–brain barrier permeability can be incorporated into the model, still allowing estimation of CTH. Materials and Methods: Twenty-three healthy subjects were scanned at 3.0T MRI system applying DCE-MRI and using a gamma-variate model to estimate CTH as well as cerebral blood flow (CBF), cerebral blood volume (CBV), and permeability of the blood–brain barrier, measured as the influx constant Ki. For proof of principle we also investigated three patients with recent thromboembolic events and a patient with a high grade brain tumor. Results: In the healthy subjects, we found a narrow symmetric delta-like capillary transit time distribution in basal ganglia gray matter with median CTH of 0.93 s and interquartile range of 1.33 s. The corresponding residue impulse response function was compatible with the adiabatic tissue homogeneity model. In two patients with complete occlusion of the internal carotid artery and in the patient with a brain tumor CTH was increased with values up to 6 s in the affected brain tissue, with an exponential like residue impulse response function. Conclusion: Our results open the possibility of characterizing brain perfusion by the capillary transit time distribution using DCE-MRI, theoretically a determinant of efficient blood to brain transport of important substances. Level of Evidence: 2. J. MAGN. RESON. IMAGING 2017;45:1809–1820.
AB - Purpose: Capillary transit time heterogeneity, measured as CTH, may set the upper limit for extraction of substances in brain tissue, e.g., oxygen. The purpose of this study was to investigate the feasibility of dynamic contrast-enhanced T1 weighted MRI (DCE-MRI) at 3 Tesla (T), in estimating CTH based on a gamma-variate model of the capillary transit time distribution. In addition, we wanted to investigate if a subtle increase of the blood–brain barrier permeability can be incorporated into the model, still allowing estimation of CTH. Materials and Methods: Twenty-three healthy subjects were scanned at 3.0T MRI system applying DCE-MRI and using a gamma-variate model to estimate CTH as well as cerebral blood flow (CBF), cerebral blood volume (CBV), and permeability of the blood–brain barrier, measured as the influx constant Ki. For proof of principle we also investigated three patients with recent thromboembolic events and a patient with a high grade brain tumor. Results: In the healthy subjects, we found a narrow symmetric delta-like capillary transit time distribution in basal ganglia gray matter with median CTH of 0.93 s and interquartile range of 1.33 s. The corresponding residue impulse response function was compatible with the adiabatic tissue homogeneity model. In two patients with complete occlusion of the internal carotid artery and in the patient with a brain tumor CTH was increased with values up to 6 s in the affected brain tissue, with an exponential like residue impulse response function. Conclusion: Our results open the possibility of characterizing brain perfusion by the capillary transit time distribution using DCE-MRI, theoretically a determinant of efficient blood to brain transport of important substances. Level of Evidence: 2. J. MAGN. RESON. IMAGING 2017;45:1809–1820.
KW - blood–brain barrier
KW - capillary transit time heterogeneity
KW - cerebral hemodynamics
KW - MRI
KW - perfusion weighted MRI
U2 - 10.1002/jmri.25488
DO - 10.1002/jmri.25488
M3 - Journal article
C2 - 27731907
AN - SCOPUS:84991112195
SN - 1053-1807
VL - 45
SP - 1809
EP - 1820
JO - Journal of Magnetic Resonance Imaging
JF - Journal of Magnetic Resonance Imaging
IS - 6
ER -