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Zarrinkoob, Laleh
Publications (10 of 12) Show all publications
Dunås, T., Wåhlin, A., Zarrinkoob, L., Malm, J. & Eklund, A. (2019). 4D flow MRI: automatic assessment of blood flow in cerebral arteries. Biomedical Physics & Engineering Express, 5(1), Article ID 015003.
Open this publication in new window or tab >>4D flow MRI: automatic assessment of blood flow in cerebral arteries
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2019 (English)In: Biomedical Physics & Engineering Express, ISSN 2057-1976, Vol. 5, no 1, article id 015003Article in journal (Refereed) Published
Abstract [en]

Objective: With a 10-minute 4D flow MRI scan, the distribution of blood flow to individual arteries throughout the brain can be analyzed. This technique has potential to become a biomarker for treatment decisions, and to predict prognosis after stroke. To efficiently analyze and model the large dataset in clinical practice, automatization is needed. We hypothesized that identification of selected arterial regions using an atlas with a priori probability information on their spatial distribution can provide standardized measurements of blood flow in the main cerebral arteries.

Approach: A new method for automatic placement of measurement locations in 4D flow MRI was developed based on an existing atlas-based method for arterial labeling, by defining specific regions of interest within the corresponding arterial atlas. The suggested method was evaluated on 38 subjects with carotid artery stenosis, by comparing measurements of blood flow rate at automatically selected locations to reference measurements at manually selected locations.

Main results: Automatic and reference measurement ranged from 10 to 580 ml min−1 and were highly correlated (r = 0.99) with a mean flow difference of 0.61 ± 10.7 ml min−1 (p = 0.21). Out of the 559 arterial segments in the manual reference, 489 were correctly labeled, yielding a sensitivity of 88%, a specificity of 85%, and a labeling accuracy of 87%.

Significance: This study confirms that atlas-based labeling of 4D flow MRI data is suitable for efficient flow quantification in the major cerebral arteries. The suggested method improves the feasibility of analyzing cerebral 4D flow data, and fills a gap necessary for implementation in clinical use.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2019
Keywords
cerebral arteries, hemodynamics, carotid stenosis, magnetic resonance imaging, circle of willis, cerebrovascular circulation
National Category
Medical Image Processing
Identifiers
urn:nbn:se:umu:diva-147254 (URN)10.1088/2057-1976/aae8d1 (DOI)000457627700003 ()
Funder
Swedish Research Council, 2015-05616Swedish Heart Lung Foundation, 20110383, 20140592
Note

Originally included in thesis in manuscript form

Available from: 2018-04-30 Created: 2018-04-30 Last updated: 2019-11-19Bibliographically approved
Zarrinkoob, L., Wåhlin, A., Ambarki, K., Birgander, R., Eklund, A. & Malm, J. (2019). Blood flow lateralization and collateral compensatory mechanisms in patients with carotid artery stenosis. Stroke, 50(5), 1081-1088
Open this publication in new window or tab >>Blood flow lateralization and collateral compensatory mechanisms in patients with carotid artery stenosis
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2019 (English)In: Stroke, ISSN 0039-2499, E-ISSN 1524-4628, Vol. 50, no 5, p. 1081-1088Article in journal (Refereed) Published
Abstract [en]

Background and Purpose: Four-dimensional phase-contrast magnetic resonance imaging enables quantification of blood flow rate (BFR; mL/min) in multiple cerebral arteries simultaneously, making it a promising technique for hemodynamic investigation in patients with stroke. The aim of this study was to quantify the hemodynamic disturbance and the compensatory pattern of collateral flow in patients with symptomatic carotid stenosis.

Methods: Thirty-eight patients (mean, 72 years; 27 men) with symptomatic carotid stenosis (>/=50%) or occlusion were investigated using 4-dimensional phase-contrast magnetic resonance imaging. For each patient, BFR was measured in 19 arteries/locations. The ipsilateral side to the symptomatic carotid stenosis was compared with the contralateral side.

Results: Internal carotid artery BFR was lower on the ipsilateral side (134+/-87 versus 261+/-95 mL/min; P<0.001). BFR in anterior cerebral artery (A1 segment) was lower on ipsilateral side (35+/-58 versus 119+/-72 mL/min; P<0.001). Anterior cerebral artery territory bilaterally was primarily supplied by contralateral internal carotid artery. The ipsilateral internal carotid artery mainly supplied the ipsilateral middle cerebral artery (MCA) territory. MCA was also supplied by a reversed BFR found in the ophthalmic and the posterior communicating artery routes on the ipsilateral side (-5+/-28 versus 10+/-28 mL/min, P=0.001, and -2+/-12 versus 6+/-6 mL/min, P=0.03, respectively). Despite these compensations, BFR in MCA was lower on the ipsilateral side, and this laterality was more pronounced in patients with severe carotid stenosis (>/=70%). Although comparing ipsilateral MCA BFR between stenosis groups (<70% and >/=70%), there was no difference ( P=0.95).

Conclusions: With a novel approach using 4-dimensional phase-contrast magnetic resonance imaging, we could simultaneously quantify and rank the importance of collateral routes in patients with carotid stenosis. An important observation was that contralateral internal carotid artery mainly secured the bilateral anterior cerebral artery territory. Because of the collateral recruitment, compromised BFR in MCA is not necessarily related to the degree of carotid stenosis. These findings highlight the importance of simultaneous investigation of the hemodynamics of the entire cerebral arterial tree.

Place, publisher, year, edition, pages
Philadelphia: Lippincott Williams & Wilkins, 2019
Keywords
carotid stenosis, circle of Willis, humans, magnetic resonance imaging, cine, middle cerebral artery
National Category
Cardiac and Cardiovascular Systems
Identifiers
urn:nbn:se:umu:diva-158003 (URN)10.1161/STROKEAHA.119.024757 (DOI)000469350000029 ()30943887 (PubMedID)
Funder
Swedish Research Council, 2015-05616Swedish Research Council, 2017-04949Västerbotten County CouncilSwedish Heart Lung Foundation, 20140592
Available from: 2019-04-10 Created: 2019-04-10 Last updated: 2019-11-19Bibliographically approved
Zarrinkoob, L. (2019). Cerebral blood flow distribution, collateral function and pulsatility in healthy and in patients with symptomatic carotid stenosis : a magnetic resonance imaging approach. (Doctoral dissertation). Umeå: Umeå universitet
Open this publication in new window or tab >>Cerebral blood flow distribution, collateral function and pulsatility in healthy and in patients with symptomatic carotid stenosis : a magnetic resonance imaging approach
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Cerebralt blodflöde med fokus på blodflödesfördelning, kollateraler och artärpulsationer, hos friska och hos patienter med symtomatisk karotisstenos : en tillämpning med magnetisk resonanstomografi
Abstract [en]

Background: For the detection and treatment of early cerebral vascular disease it is of paramount importance to first understand the normal physiology of the cerebral vasculature, and subsequently, to understand how and when pathology can develop from that. This is especially important as the population above 65 years of age is increasing and aging itself is an established risk factor for the development of cerebral vascular disease. This, however, is not always an easy task, since there is a subtle balance and overlap between age-related physiological and pathophysiological changes in the arterial system. Atherosclerotic changes that lead to the development of carotid artery stenosis are responsible for about one fifth of all ischemic strokes. Today, the current state of evidence and the algorithm for carotid revascularization is mainly focused on the degree of carotid stenosis and not on its impact on cerebral hemodynamics. One reason for this is the lack of a non-invasive method, that allows for repeated investigations and provides accurate and reliable results to study cerebral hemodynamic changes. The overall aim of this thesis was to explore and develop a comprehensive approach to investigate the cerebral blood flow distribution, collateral function and pulsatility in healthy subjects and in patients with symptomatic carotid stenosis using a phase-contrast magnetic resonance imaging (PCMRI) platform. The thesis is based on four scientific papers (papers I—IV). 

Methods: In papers I and II, 49 healthy young (mean 25 years) and 45 healthy elderly (mean 71 years) subjects were included. 2D PCMRI was used to assess cerebral blood flow rate (BFR), pulsatility index (PI) and dampening factor (DF) in 15 cerebral arteries and in the ophthalmic arteries (OA). Thirty-eight patients (mean 72 years) with symptomatic carotid stenosis were included in paper III. Nineteen of these patients (mean 71 years) underwent carotid endarterectomy (CEA) (paper IV). 4D PCMRI was used for BFR assessment in papers III and IV. BFR, its distribution and collateral routes, was measured in 17 cerebral arteries and in the OA. The BFR on ipsilateral side (with symptomatic stenosis) was compared to the contralateral side (papers III and IV). BFR laterality was defined as contralateral BFR minus ipsilateral BFR in paired arteries and, BFR was compared before and after CEA (paper IV).

Results: On average, in healthy subjects, 72% of the total cerebral blood flow (tCBF) was distributed through the anterior circulation and 28% through the posterior circulation. The distribution was symmetrical and not affected by age, sex, or brain volume (paper I). Aging resulted in lower BFRs, increased pulsatility and reduced dampening capacity in cerebral arteries. Anatomical variations in the circle of Willis resulted in an asymmetrical distribution of blood flow (papers I and II). In patients with carotid stenosis, a lower BFR was found in the internal carotid artery (ICA) and its branches on the ipsilateral side. The anterior cerebral artery territory was bilaterally, primarily, supplied by the contralateral ICA. In addition to the supply through the ICA, the middle cerebral artery (MCA) territory on the ipsilateral side was secured by collateral supply from the OA and the posterior communicating arteries, seen as retrograde flow in those arteries. Despite these compensations, BFR in ipsilateral side MCA was lower, and this laterality was more pronounced in patients with severe carotid stenosis (≥70%). After CEA, the distribution of BFR going into the cerebral arteries was found to be symmetrically distributed. Total CBF increased postoperatively in patients with collateral recruitment preoperatively (n=9). The BFR laterality in MCA observed prior to CEA, was found only in the group of patients with collateral recruitment preoperatively (paper IV). The degree of stenosis did not differ between the groups with and without collateral recruitment. 

Conclusions: This thesis provides a new and comprehensive approach to mapping and quantifying normal cerebral blood flow and pulsatility. By presenting the distribution of tCBF going into cerebral arteries, instead of using absolute values, the effect of age could be neutralized and the results can be applicable when describing healthy cerebral blood flow, regardless of age. 4D PCMRI made it possible to describe the altered blood flow distribution and collateral ranking in patients with carotid stenosis prior to CEA and its normalization after the procedure. Our findings highlight the importance of BFR quantification for understanding cerebral hemodynamics in patients with carotid stenosis. 4D PCMRI technique is a promising clinical tool for investigations of cerebral hemodynamics in patients with stroke.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2019. p. 63
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 2023
Keywords
Aging, Arterial pulsatility, Carotid stenosis, Cerebral arteries, Cerebral blood flow, Cerebral collateral blood flow, Circle of Willis, Phase contrast magnetic resonance imaging
National Category
Neurology
Identifiers
urn:nbn:se:umu:diva-158834 (URN)978-91-7855-036-4 (ISBN)
Public defence
2019-06-05, Hörsal B, Unod T9, Norrlands universitetssjukhus, Umeå, 13:00 (English)
Opponent
Supervisors
Funder
Swedish Heart Lung Foundation, 20140592Swedish Research Council, 2015-05616
Available from: 2019-05-15 Created: 2019-05-09 Last updated: 2019-05-14Bibliographically approved
Dunås, T., Wåhlin, A., Ambarki, K., Zarrinkoob, L., Malm, J. & Eklund, A. (2017). A Stereotactic Probabilistic Atlas for the Major Cerebral Arteries. Neuroinformatics, 15(1), 101-110
Open this publication in new window or tab >>A Stereotactic Probabilistic Atlas for the Major Cerebral Arteries
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2017 (English)In: Neuroinformatics, ISSN 1539-2791, E-ISSN 1559-0089, Vol. 15, no 1, p. 101-110Article in journal (Refereed) Published
Abstract [en]

Improved whole brain angiographic and velocity-sensitive MRI is pushing the boundaries of noninvasively obtained cerebral vascular flow information. The complexity of the information contained in such datasets calls for automated algorithms and pipelines, thus reducing the need of manual analyses by trained radiologists. The objective of this work was to lay the foundation for such automated pipelining by constructing and evaluating a probabilistic atlas describing the shape and location of the major cerebral arteries. Specifically, we investigated how the implementation of a non-linear normalization into Montreal Neurological Institute (MNI) space improved the alignment of individual arterial branches. In a population-based cohort of 167 subjects, age 64-68 years, we performed 4D flow MRI with whole brain volumetric coverage, yielding both angiographic and anatomical data. For each subject, sixteen cerebral arteries were manually labeled to construct the atlas. Angiographic data were normalized to MNI space using both rigid-body and non-linear transformations obtained from anatomical images. The alignment of arterial branches was significantly improved by the non-linear normalization (p < 0.001). Validation of the atlas was based on its applicability in automatic arterial labeling. A leave-one-out validation scheme revealed a labeling accuracy of 96 %. Arterial labeling was also performed in a separate clinical sample (n = 10) with an accuracy of 92.5 %. In conclusion, using non-linear spatial normalization we constructed an artery-specific probabilistic atlas, useful for cerebral arterial labeling.

Keywords
Cerebral arteries, Probabilistic atlas, 4D flow MRI, Automatic labeling, Spatial normalization
National Category
Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-131144 (URN)10.1007/s12021-016-9320-y (DOI)000394260000009 ()27873151 (PubMedID)2-s2.0-84996542654 (Scopus ID)
Available from: 2017-02-06 Created: 2017-02-06 Last updated: 2018-06-09Bibliographically approved
Zarrinkoob, L., Ambarki, K., Wåhlin, A., Birgander, R., Carlberg, B., Eklund, A. & Malm, J. (2016). Aging alters the dampening of pulsatile blood flow in cerebral arteries. Journal of Cerebral Blood Flow and Metabolism, 36(9), 1519-1527
Open this publication in new window or tab >>Aging alters the dampening of pulsatile blood flow in cerebral arteries
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2016 (English)In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 36, no 9, p. 1519-1527Article in journal (Refereed) Published
Abstract [en]

Excessive pulsatile flow caused by aortic stiffness is thought to be a contributing factor for several cerebrovascular diseases. The main purpose of this study was to describe the dampening of the pulsatile flow from the proximal to the distal cerebral arteries, the effect of aging and sex, and its correlation to aortic stiffness. Forty-five healthy elderly (mean age 71 years) and 49 healthy young (mean age 25 years) were included. Phase-contrast magnetic resonance imaging was used for measuring blood flow pulsatility index and dampening factor (proximal artery pulsatility index/distal artery pulsatility index) in 21 cerebral and extra-cerebral arteries. Aortic stiffness was measured as aortic pulse wave velocity. Cerebral arterial pulsatility index increased due to aging and this was more pronounced in distal segments of cerebral arteries. There was no difference in pulsatility index between women and men. Dampening of pulsatility index was observed in all cerebral arteries in both age groups but was significantly higher in young subjects than in elderly. Pulse wave velocity was not correlated with cerebral arterial pulsatility index. The increased pulsatile flow in elderly together with reduced dampening supports the pulse wave encephalopathy theory, since it implies that a higher pulsatile flow is reaching distal arterial segments in older subjects.

National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-126505 (URN)10.1177/0271678X16629486 (DOI)000382996800004 ()26823470 (PubMedID)
Available from: 2016-10-27 Created: 2016-10-10 Last updated: 2019-05-09Bibliographically approved
Dunås, T., Wåhlin, A., Ambarki, K., Zarrinkoob, L., Birgander, R., Malm, J. & Eklund, A. (2016). Automatic labeling of cerebral arteries in magnetic resonance angiography. Magnetic Resonance Materials in Physics, Biology and Medicine, 29(1), 39-47
Open this publication in new window or tab >>Automatic labeling of cerebral arteries in magnetic resonance angiography
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2016 (English)In: Magnetic Resonance Materials in Physics, Biology and Medicine, ISSN 0968-5243, E-ISSN 1352-8661, Vol. 29, no 1, p. 39-47Article in journal (Refereed) Published
Abstract [en]

In order to introduce 4D flow magnetic resonance imaging (MRI) as a standard clinical instrument for studying the cerebrovascular system, new and faster postprocessing tools are necessary. The objective of this study was to construct and evaluate a method for automatic identification of individual cerebral arteries in a 4D flow MRI angiogram. Forty-six elderly individuals were investigated with 4D flow MRI. Fourteen main cerebral arteries were manually labeled and used to create a probabilistic atlas. An automatic atlas-based artery identification method (AAIM) was developed based on vascular-branch extraction and the atlas was used for identification. The method was evaluated by comparing automatic with manual identification in 4D flow MRI angiograms from 67 additional elderly individuals. Overall accuracy was 93 %, and internal carotid artery and middle cerebral artery labeling was 100 % accurate. Smaller and more distal arteries had lower accuracy; for posterior communicating arteries and vertebral arteries, accuracy was 70 and 89 %, respectively. The AAIM enabled fast and fully automatic labeling of the main cerebral arteries. AAIM functionality provides the basis for creating an automatic and powerful method to analyze arterial cerebral blood flow in clinical routine.

Keywords
Magnetic resonance angiography, Cerebral angiography, Circle of Willis, Atlases as topic, Automatic data processing
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-117830 (URN)10.1007/s10334-015-0512-5 (DOI)000370159800005 ()
Available from: 2016-04-05 Created: 2016-03-04 Last updated: 2018-06-07Bibliographically approved
Ambarki, K., Wåhlin, A., Zarrinkoob, L., Wirestam, R., Petr, J., Malm, J. & Eklund, A. (2015). Accuracy of Parenchymal Cerebral Blood Flow Measurements Using Pseudocontinuous Arterial Spin-Labeling in Healthy Volunteers. American Journal of Neuroradiology, 36(10), 1816-1821
Open this publication in new window or tab >>Accuracy of Parenchymal Cerebral Blood Flow Measurements Using Pseudocontinuous Arterial Spin-Labeling in Healthy Volunteers
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2015 (English)In: American Journal of Neuroradiology, ISSN 0195-6108, E-ISSN 1936-959X, Vol. 36, no 10, p. 1816-1821Article in journal (Refereed) Published
Abstract [en]

BACKGROUND AND PURPOSE: The arterial spin-labeling method for CBF assessment is widely available, but its accuracy is not fully established. We investigated the accuracy of a whole-brain arterial spin-labeling technique for assessing the mean parenchymal CBF and the effect of aging in healthy volunteers. Phase-contrast MR imaging was used as the reference method. MATERIALS AND METHODS: Ninety-two healthy volunteers were included: 49 young (age range, 20-30 years) and 43 elderly (age range, 65-80 years). Arterial spin-labeling parenchymal CBF values were averaged over the whole brain to quantify the mean pCBF(ASL) value. Total. CBF was assessed with phase-contrast MR imaging as the sum of flows in the internal carotid and vertebral arteries, and subsequent division by brain volume returned the pCBF(PCMRI) value. Accuracy was considered as good as that of the reference method if the systematic difference was less than 5 mL/min/100 g of brain tissue and if the 95% confidence intervals were equal to or better than +/- 10 mL/min/100 g. RESULTS: pCBF(ASL) correlated to pCBF(PCMRI) (r = 0.73; P < .001). Significant differences were observed between the pCBF(ASL) and pCBF(PCMRI) values in the young (P = .001) and the elderly (P < .001) volunteers. The systematic differences (mean 2 standard deviations) were -4 +/- 14 mL/min/100 g in the young subjects and 6 +/- 12 mL/min/100 g in the elderly subjects. Young subjects showed higher values than the elderly subjects for pCBF(PCMRI) (young, 57 +/- 8 mL/min/100 g; elderly, 54 +/- 7 mL/min/100 g; P = .05) and pCBF(ASL) (young, 61 +/- 10 mL/min/100 g; elderly, 48 +/- 10 mL/min/100 g; P < .001). CONCLUSIONS: The limits of agreement were too wide for the arterial spin-labeling method to be considered satisfactorily accurate, whereas the systematic overestimation in the young subjects and underestimation in the elderly subjects were close to acceptable. The age-related decrease in parenchymal CBF was augmented in arterial spin-labeling compared with phase-contrast MR imaging.

National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-111006 (URN)10.3174/ajnr.A4367 (DOI)000362700900006 ()26251434 (PubMedID)
Available from: 2015-11-04 Created: 2015-11-02 Last updated: 2018-06-07Bibliographically approved
Zarrinkoob, L., Ambarki, K., Wåhlin, A., Birgander, R., Eklund, A. & Malm, J. (2015). Blood flow distribution in cerebral arteries. Journal of Cerebral Blood Flow and Metabolism, 35(4), 648-654
Open this publication in new window or tab >>Blood flow distribution in cerebral arteries
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2015 (English)In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 35, no 4, p. 648-654Article in journal (Refereed) Published
Abstract [en]

High-resolution phase-contrast magnetic resonance imaging can now assess flow in proximal and distal cerebral arteries. The aim of this study was to describe how total cerebral blood flow (tCBF) is distributed into the vascular tree with regard to age, sex and anatomic variations. Forty-nine healthy young (mean 25 years) and 45 elderly (mean 71 years) individuals were included. Blood flow rate (BFR) in 21 intra-and extracerebral arteries was measured. Total cerebral blood flow was defined as BFR in the internal carotid plus vertebral arteries and mean cerebral perfusion as tCBF/brain volume. Carotid/vertebral distribution was 72%/28% and was not related to age, sex, or brain volume. Total cerebral blood flow (717 +/- 123 mL/min) was distributed to each side as follows: middle cerebral artery (MCA), 21%; distal MCA, 6%; anterior cerebral artery (ACA), 12%, distal ACA, 4%; ophthalmic artery, 2%; posterior cerebral artery (PCA), 8%; and 20% to basilar artery. Deviating distributions were observed in subjects with 'fetal' PCA. Blood flow rate in cerebral arteries decreased with increasing age (P < 0.05) but not in extracerebral arteries. Mean cerebral perfusion was higher in women (women: 61 +/- 8; men: 55 +/- 6 mL/min/100 mL, P < 0.001). The study describes a new method to outline the flow profile of the cerebral vascular tree, including reference values, and should be used for grading the collateral flow system.

Keywords
aging, cerebral blood flow, circle of Willis, cognitive impairment, phase-contrast MRI, stroke
National Category
Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-103545 (URN)10.1038/jcbfm.2014.241 (DOI)000352027900015 ()25564234 (PubMedID)
Available from: 2015-05-25 Created: 2015-05-21 Last updated: 2019-05-09Bibliographically approved
Ambarki, K., Petr, J., Wahlin, A., Wirestam, R., Zarrinkoob, L., Malm, J. & Eklund, A. (2015). Partial Volume Correction of Cerebral Perfusion Estimates Obtained by Arterial Spin Labeling. In: 16th Nordic-Baltic Conference on Biomedical Engineering: 16. NBC & 10. MTD 2014 joint conferences. October 14-16, 2014, Gothenburg, Sweden. Paper presented at 16th Nordic-Baltic Conference on Biomedical Engineering, October 14-16, 2014, Gothenburg, Sweden (pp. 17-19). , 48
Open this publication in new window or tab >>Partial Volume Correction of Cerebral Perfusion Estimates Obtained by Arterial Spin Labeling
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2015 (English)In: 16th Nordic-Baltic Conference on Biomedical Engineering: 16. NBC & 10. MTD 2014 joint conferences. October 14-16, 2014, Gothenburg, Sweden, 2015, Vol. 48, p. 17-19Conference paper, Published paper (Refereed)
Abstract [en]

Arterial Spin labeling (ASL) is a fully non-invasive MRI method capable to quantify cerebral perfusion. However, gray (GM) and white matter (WM) ASL perfusions are difficult to assess separately due to limited spatial resolution increasing the partial volume effects (PVE). In the present study, ASL PVE correction was implemented based on a regression algorithm in 22 healthy young men. PVE corrected perfusion of GM and WM were compared to previous studies. PVE-corrected GM perfusion was in agreement with literature values. In general, WM perfusion was higher despite the use of PVE correction.

Series
IFMBE Proceedings, ISSN 1680-0737 ; 48
Keywords
MRI, cerebral perfusion, gray and white matter, arterial spin labeling and healthy
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-100142 (URN)10.1007/978-3-319-12967-9_5 (DOI)000347893000005 ()978-3-319-12966-2 (ISBN)978-3-319-12967-9 (ISBN)
Conference
16th Nordic-Baltic Conference on Biomedical Engineering, October 14-16, 2014, Gothenburg, Sweden
Available from: 2015-02-26 Created: 2015-02-24 Last updated: 2018-06-07Bibliographically approved
Dunås, T., Wåhlin, A., Zarrinkoob, L., Ambarki, K., Malm, J. & Eklund, A. (2015). Towards Automatic Identification of Cerebral Arteries in 4D Flow MRI. In: Henrik Mindedal, Mikael Persson (Ed.), 16th Nordic-Baltic Conference on Biomedical Engineering: . Paper presented at 16th Nordic-Baltic Conference on Biomedical Engineering, October 14-16, 2014, Gothenburg, Sweden (pp. 40-43). , 48
Open this publication in new window or tab >>Towards Automatic Identification of Cerebral Arteries in 4D Flow MRI
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2015 (English)In: 16th Nordic-Baltic Conference on Biomedical Engineering / [ed] Henrik Mindedal, Mikael Persson, 2015, Vol. 48, p. 40-43Conference paper, Published paper (Refereed)
Abstract [en]

4D flow MRI is a powerful imaging technique which provides an angiographic image with information about blood flow in a large volume, time resolved over the cardiac cycle, in a short imaging time. This study aims to develop an automatic method for identification of cerebral arteries. The proposed method is based on an atlas of twelve arteries, developed from 4D flow MRI of 25 subjects. The atlas was constructed by normalizing all images to MNI-space, manually identifying the arteries and creating an average over the volume. The identification is done by extracting a vascular skeleton from the image, transforming it to MNI-space, labeling it with the atlas and transforming it back to subject space. The method was evaluated on a pilot cohort of 8 subjects. The rate of correctly identified arteries was 97%.

Series
IFMBE Proceedings, ISSN 1680-0737 ; 48
Keywords
Cerebral arteries, automatic labeling, 4D flow MRI, cerebrovascular atlas
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-100149 (URN)10.1007/978-3-319-12967-9_11 (DOI)000347893000011 ()978-3-319-12966-2 (ISBN)978-3-319-12967-9 (ISBN)
Conference
16th Nordic-Baltic Conference on Biomedical Engineering, October 14-16, 2014, Gothenburg, Sweden
Available from: 2015-02-26 Created: 2015-02-24 Last updated: 2018-06-07Bibliographically approved
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