BACKGROUND AND PURPOSE: The heterogeneity of microvascular flows is known to be an important determinant of the efficacy of oxygen delivery to tissue. Studies in animals have demonstrated decreased flow heterogeneity (FH) in states of decreased perfusion pressure. The purpose of the present study was to assess microvascular FH changes in acute stroke with use of a novel perfusion-weighted MRI technique and to evaluate the ability of combined diffusion-weighted MRI and FH measurements to predict final infarct size. METHODS: Cerebral blood flow, FH, and plasma mean transit time (MTT) were measured in 11 patients who presented with acute (<12 hours after symptom onset) stroke. Final infarct size was determined with follow-up MRI or CT scanning. RESULTS: In normal brain tissue, the distribution of relative flows was markedly skewed toward high capillary flow velocities. Within regions of decreased cerebral blood flow, plasma MTT was prolonged. Furthermore, subregions were identified with significant loss of the high-flow component of the flow distribution, thereby causing increased homogeneity of flow velocities. In parametric maps that quantify the acute deviation of FH from that of normal tissue, areas of extreme homogenization of capillary flows predicted final infarct size on follow-up scans of 10 of 11 patients. CONCLUSIONS: Flow heterogeneity and MTT can be rapidly assessed as part of a routine clinical MR examination and may provide a tool for planning of individual stroke treatment, as well as in targeting and evaluation of emerging therapeutic strategies.
BACKGROUND AND PURPOSE: The heterogeneity of microvascular flows is known to be an important determinant of the efficacy of oxygen delivery to tissue. Studies in animals have demonstrated decreased flow heterogeneity (FH) in states of decreased perfusion pressure. The purpose of the present study was to assess microvascular FH changes in acute stroke with use of a novel perfusion-weighted MRI technique and to evaluate the ability of combined diffusion-weighted MRI and FH measurements to predict final infarct size. METHODS: Cerebral blood flow, FH, and plasma mean transit time (MTT) were measured in 11 patients who presented with acute (<12 hours after symptom onset) stroke. Final infarct size was determined with follow-up MRI or CT scanning. RESULTS: In normal brain tissue, the distribution of relative flows was markedly skewed toward high capillary flow velocities. Within regions of decreased cerebral blood flow, plasma MTT was prolonged. Furthermore, subregions were identified with significant loss of the high-flow component of the flow distribution, thereby causing increased homogeneity of flow velocities. In parametric maps that quantify the acute deviation of FH from that of normal tissue, areas of extreme homogenization of capillary flows predicted final infarct size on follow-up scans of 10 of 11 patients. CONCLUSIONS: Flow heterogeneity and MTT can be rapidly assessed as part of a routine clinical MR examination and may provide a tool for planning of individual stroke treatment, as well as in targeting and evaluation of emerging therapeutic strategies.
Authors: Mohammed Salman Shazeeb; Robert M King; Olivia W Brooks; Ajit S Puri; Nils Henninger; Johannes Boltze; Matthew J Gounis Journal: Transl Stroke Res Date: 2019-09-03 Impact factor: 6.829
Authors: Tina Young Poussaint; Mehmet Kocak; Sridhar Vajapeyam; Roger I Packer; Richard L Robertson; Russell Geyer; Daphne Haas-Kogan; Ian F Pollack; Gilbert Vezina; Robert Zimmerman; Soonmee Cha; Zoltan Patay; James M Boyett; Larry E Kun Journal: Neuro Oncol Date: 2011-02-04 Impact factor: 12.300
Authors: Fernando E Boada; Yongxian Qian; Edwin Nemoto; Tudor Jovin; Charles Jungreis; S C Jones; Jonathan Weimer; Vincent Lee Journal: Transl Stroke Res Date: 2012-05-04 Impact factor: 6.829
Authors: Mahesh P Kate; Mikkel B Hansen; Kim Mouridsen; Leif Østergaard; Victor Choi; Bronwen E Gould; Rebecca McCourt; Michael D Hill; Andrew M Demchuk; Shelagh B Coutts; Dariush Dowlatshahi; Derek J Emery; Brian H Buck; Kenneth S Butcher Journal: J Cereb Blood Flow Metab Date: 2013-09-18 Impact factor: 6.200
Authors: T Young Poussaint; P C Phillips; S Vajapeyam; F H Fahey; R L Robertson; S Osganian; U Ramamurthy; R V Mulkern; S T Treves; J M Boyett; L E Kun Journal: AJNR Am J Neuroradiol Date: 2007-04 Impact factor: 3.825