Heide, EJ de (Erik-Jan) (2017) Collateral blood flow and flow territory imaging with territorial arterial spin labeling in acute stroke. thesis, Medicine.
Full text available on request.Abstract
Introduction Acute ischemic stroke is a debilitating disorder with a large impact on both patient and society. Collateral blood flow to tissue at risk plays a pivotal role in sustaining adequate brain tissue oxygenation. Currently, the presence of collaterals in the brain can be deducted from back-flow on CT or MRI, using exogenous contrast. Arterial spin labeling (ASL) is a technique in which no exogenous contrast is needed to adequately evaluate the blood flow. In the quest for personalized stroke treatment collateral imaging may prove a valuable addition. Purpose The aim of this thesis was to evaluate the feasibility of territorial ASL imaging in acute stroke and to evaluate whether territorial ASL can map a change in vascular territories in arterial occlusion in the treatment of ischemic stroke patients. Materials and methods This is a retrospective study for which data was obtained from the Natural History of Stroke: Cause and Development Trial, a prospective multi-center study of acute stroke patients. Data was acquired from patients presenting at Washington Hospital Center, Washington, DC, USA. The imaging protocol consisted of a 2-hour, 24-hour, 5-day and 30-day scan, using standard clinical stroke protocol sequences and a time of flight angiogram, 2D phase-contrast (PC) through the circle of Willis and a pseudo-continuous territorial ASL (pcTASL) sequence. The images were analyzed blinded from clinical data and other imaging. The primary end point was the qualitative assessment of the imaging. Secondary endpoints were the shift of vascular territory during treatment of ischemic stroke and clinical outcomes. Results In total 93 patients were included in the image quality assessment, 61 were of sufficient quality to be assessed for collateral flow and flow territories. 80,9% of the territorial perfusion maps was interpretable. 33 patients had signs of collateralization, 10 of whom showed changes in vascular distribution over time. The agreement in flow direction of collaterals as seen on pcTASL and PC MRI was 96%. The differences in the occurrence of a shift of vascular distribution over time was not significantly correlated to the presence of signs of collateralization on territorial ASL. There was no significant difference in clinical outcomes as measured in the modified Rankin Scale between the groups with and without signs of collaterals on territorial ASL. Conclusion PcTASL is feasible in acute patient follow-up. The image quality is good, as is the agreement of collateral flow direction between pcTASL and PC MRI. The territorial perfusion maps give information on collateral circulation, recanalization and redistribution of blood flow in the brain. The presence of collaterals on these images is not significantly correlated to clinical outcomes. With more research, pcTASL could prove a useful addition to patient selection in stroke treatment.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Supervisor: and Bokkers, dr. R.P.H. and interventional radiologist and Medical Imaging Center, department of Radiology and University Medical Center Groningen |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 10:51 |
| Last Modified: | 25 Jun 2020 10:51 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/1192 |
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