1
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Hoogeveen ES, Arkink EB, van der Grond J, van Buchem MA, Ferrari MD, Terwindt GM, Kruit MC. MRI evaluation of the relationship between carotid artery endothelial shear stress and brain white matter lesions in migraine. J Cereb Blood Flow Metab 2020; 40:1040-1047. [PMID: 31213163 PMCID: PMC7178149 DOI: 10.1177/0271678x19857810] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Although white matter lesions are frequently detected in migraine patients, underlying mechanisms remain unclear. Low carotid artery endothelial shear stress has been associated with white matter lesions. We aimed to investigate the association between carotid artery endothelial shear stress and white matter lesions in migraine. In 40 elderly migraine patients (n = 29 females, 75 years [SD 3]) and 219 controls (n = 80 females, 74 years [SD 3]) from the PROSPER-MRI study, carotid artery endothelial shear stress was estimated on 1.5 T gradient-echo phase contrast MRI. White matter lesion volumes were calculated from structural MRI scans. Analyses were adjusted for age, sex, cardiovascular risk factors and cardiovascular disease. Migraine patients had lower mean endothelial shear stress compared to controls (0.90 [SD 0.15] vs. 0.98 [SD 0.16] Pa; P = 0.03). The association between mean endothelial shear stress and white matter lesion volume was greater for the migraine group than control group (P for interaction = 0.05). Within the migraine group, white matter lesion volume increased with decreasing endothelial shear stress (β-0.421; P = 0.01). In conclusion, migraine patients had lower endothelial shear stress which was associated with higher white matter lesion volume.
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Affiliation(s)
- Evelien S Hoogeveen
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Enrico B Arkink
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jeroen van der Grond
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mark A van Buchem
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michel D Ferrari
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Gisela M Terwindt
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mark C Kruit
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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2
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Ikram MA, Zonneveld HI, Roshchupkin G, Smith AV, Franco OH, Sigurdsson S, van Duijn C, Uitterlinden AG, Launer LJ, Vernooij MW, Gudnason V, Adams HH. Heritability and genome-wide associations studies of cerebral blood flow in the general population. J Cereb Blood Flow Metab 2018; 38. [PMID: 28627999 PMCID: PMC6120124 DOI: 10.1177/0271678x17715861] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cerebral blood flow is an important process for brain functioning and its dysregulation is implicated in multiple neurological disorders. While environmental risk factors have been identified, it remains unclear to what extent the flow is regulated by genetics. Here we performed heritability and genome-wide association analyses of cerebral blood flow in a population-based cohort study. We included 4472 persons free of cortical infarcts who underwent genotyping and phase-contrast magnetic resonance flow imaging (mean age 64.8 ± 10.8 years). The flow rate, cross-sectional area of the vessel, and flow velocity through the vessel were measured in the basilar artery and bilateral carotids. We found that the flow rate of the basilar artery is most heritable (h2 (SE) = 24.1 (9.8), p-value = 0.0056), and this increased over age. The association studies revealed two significant loci for the right carotid artery area (rs12546630, p-value = 2.0 × 10-8) and velocity (rs2971609, p-value = 1.4 × 10-8), with the latter showing a concordant effect in an independent sample (N = 1350, p-value = 0.057, meta-analyzed p-value = 2.5 × 10-9). These loci were also associated with other cerebral blood flow parameters below genome-wide significance, and rs2971609 lies in a known migraine locus. These findings establish that cerebral blood flow is under genetic control with potential relevance for neurological diseases.
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Affiliation(s)
- M Arfan Ikram
- 1 Department of Epidemiology, Erasmus MC, Rotterdam, the Netherlands.,2 Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands.,3 Department of Neurology, Erasmus MC, Rotterdam, the Netherlands
| | - Hazel I Zonneveld
- 1 Department of Epidemiology, Erasmus MC, Rotterdam, the Netherlands.,2 Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands
| | - Gennady Roshchupkin
- 2 Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands.,4 Department of Medical Informatics, Erasmus MC, Rotterdam, the Netherlands
| | - Albert V Smith
- 5 Icelandic Heart Association, Kopavogur, Iceland.,6 Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Oscar H Franco
- 1 Department of Epidemiology, Erasmus MC, Rotterdam, the Netherlands
| | | | | | | | | | - Meike W Vernooij
- 1 Department of Epidemiology, Erasmus MC, Rotterdam, the Netherlands.,2 Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands
| | - Vilmundur Gudnason
- 5 Icelandic Heart Association, Kopavogur, Iceland.,6 Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Hieab Hh Adams
- 1 Department of Epidemiology, Erasmus MC, Rotterdam, the Netherlands.,2 Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands
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3
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Quantitative phase-contrast MRI study of cerebrospinal fluid flow: a method for identifying patients with normal-pressure hydrocephalus. NEUROLOGÍA (ENGLISH EDITION) 2014. [DOI: 10.1016/j.nrleng.2013.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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4
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Forner Giner J, Sanz-Requena R, Flórez N, Alberich-Bayarri A, García-Martí G, Ponz A, Martí-Bonmatí L. Quantitative phase-contrast MRI study of cerebrospinal fluid flow: a method for identifying patients with normal-pressure hydrocephalus. Neurologia 2013; 29:68-75. [PMID: 23643684 DOI: 10.1016/j.nrl.2013.02.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 02/19/2013] [Accepted: 02/27/2013] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES The aim of this study is to evaluate the use of phase-contrast MR imaging to diagnose normal pressure hydrocephalus (NPH) and differentiate it from other neurological disorders with similar clinical symptoms. METHODS The study included 108 subjects, of whom 61 were healthy controls and 47, patients; in the patient group, 19 had cerebrovascular disease (CVD) and 28 had NPH. All patients underwent a phase-contrast MRI study and several CSF flow and velocity parameters were measured at the aqueduct of Sylvius. Discriminant analyses were performed to evaluate the classification capacity of both individual parameters and the combination of different parameters. RESULTS Maximum diastolic velocity, mean flow, and stroke volume showed statistically significant differences that could be used to distinguish between NPH and CVD patients (P<.001). Stroke volume and mean flow showed no false positive results and successful classification rates of 86% and 79%, respectively. No other parameters or combination produced better results. CONCLUSIONS Phase-contrast MR imaging is a useful tool for the early diagnosis of patients with NPH. CSF flow quantitative parameters, along with morphological features in a conventional MR study, enable us to differentiate between NPH and CVD patients.
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Affiliation(s)
- J Forner Giner
- Servicio de Radiología, Hospital Quirón Valencia, Valencia, España.
| | - R Sanz-Requena
- Servicio de Radiología, Hospital Quirón Valencia, Valencia, España
| | - N Flórez
- Universidad de Santo Tomás, Bucaramanga, Colombia
| | | | - G García-Martí
- Servicio de Radiología, Hospital Quirón Valencia, Valencia, España; CIBER-SAM, ISCIII, Valencia, España
| | - A Ponz
- Servicio de Neurología, Hospital Clínic Universitari de Valencia, Valencia, España
| | - L Martí-Bonmatí
- Servicio de Radiología, Hospital Quirón Valencia, Valencia, España; Unidad de Radiología, Facultad de Medicina, Universidad de Valencia, Valencia, España
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5
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Versluis B, Dremmen MHG, Nelemans PJ, Wildberger JE, Schurink GW, Leiner T, Backes WH. MRI of arterial flow reserve in patients with intermittent claudication: feasibility and initial experience. PLoS One 2012; 7:e31514. [PMID: 22412836 PMCID: PMC3297594 DOI: 10.1371/journal.pone.0031514] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Accepted: 01/11/2012] [Indexed: 01/28/2023] Open
Abstract
Objectives The aim of this work was to develop a MRI method to determine arterial flow reserve in patients with intermittent claudication and to investigate whether this method can discriminate between patients and healthy control subjects. Methods Ten consecutive patients with intermittent claudication and 10 healthy control subjects were included. All subjects underwent vector cardiography triggered quantitative 2D cine MR phase-contrast imaging to obtain flow waveforms of the popliteal artery at rest and during reactive hyperemia. Resting flow, maximum hyperemic flow and absolute flow reserve were determined and compared between the two groups by two independent MRI readers. Also, interreader reproducibility of flow measures was reported. Results Resting flow was lower in patients compared to controls (4.9±1.6 and 11.1±3.2 mL/s in patients and controls, respectively (p<0.01)). Maximum hyperemic flow was 7.3±2.9 and 16.4±3.2 mL/s (p<0.01) and the absolute flow reserve was 2.4±1.6 and 5.3±1.3 mL/s (p<0.01), respectively in patients and controls. The interreader coefficient of variation was below 10% for all measures in both patients and controls. Conclusions Quantitative 2D MR cine phase-contrast imaging is a promising method to determine flow reserve measures in patients with peripheral arterial disease and can be helpful to discriminate patients with intermittent claudication from healthy controls.
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Affiliation(s)
- Bas Versluis
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
| | | | - Patty J. Nelemans
- Department of Epidemiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Joachim E. Wildberger
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
| | - Geert-Willem Schurink
- Department of Surgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Tim Leiner
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Walter H. Backes
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
- * E-mail:
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6
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Odille F, Steeden JA, Muthurangu V, Atkinson D. Automatic segmentation propagation of the aorta in real-time phase contrast MRI using nonrigid registration. J Magn Reson Imaging 2010; 33:232-8. [DOI: 10.1002/jmri.22402] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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7
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Totman JJ, Marciani L, Foley S, Campbell E, Hoad CL, Macdonald IA, Spiller RC, Gowland PA. Characterization of the time course of the superior mesenteric, abdominal aorta, internal carotid and vertebral arteries blood flow response to the oral glucose challenge test using magnetic resonance imaging. Physiol Meas 2009; 30:1117-36. [PMID: 19759401 DOI: 10.1088/0967-3334/30/10/011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Blood flow to the splanchnic circulation increases postprandially which may cause a reduction in systemic and cerebral perfusion leading to postprandial syncope in the elderly who lack adequate cardiovascular reserve. We used multi-station 2D phase contrast cine magnetic resonance imaging (PC-MRI) with the aim of characterizing the time course of the haemodynamic response to an oral glucose challenge test (OGCT) in the large arteries perfusing the splanchnic, systemic and cerebral circulations (superior mesenteric artery SMA, abdominal aorta AA, internal carotid arteries, ICA and vertebral arteries VA). In this study nine fasted healthy volunteers were studied. Separate cine PC-MRI scans were acquired in the neck and in the abdomen every 88 s, these two measurements being interleaved for ten baseline scans at each station with the scanner automatically moving the subject between the two stations. After ingestion of the OGCT, a further 30 cine PC-MRI scans were acquired at each station. Using this technique we were able to characterize with frequent sampling of volumetric blood flow the time course of blood flow response to the OGCT of the SMA, AA and both VA and ICA. We found a substantial variation between individuals in the amplitude and the time to the peak of the SMA blood flow response to the OGCT which correlated positively with body mass index. MRI provides a robust, non-invasive method of studying normal physiology that could be valuable in studies of diseases such as postprandial hypotension.
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Affiliation(s)
- J J Totman
- Brain and Body Centre, University of Nottingham, Nottingham NG7 2RD, UK
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8
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Hansen JM, Pedersen DL, Larsen VA, Sánchez-del-Rio M, Alvarez Linera JR, Olesen J, Ashina M. Magnetic resonance angiography shows dilatation of the middle cerebral artery after infusion of glyceryl trinitrate in healthy volunteers. Cephalalgia 2007; 27:118-27. [PMID: 17257231 DOI: 10.1111/j.1468-2982.2006.01257.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous studies have reported dilatation of the middle cerebral artery (MCA) during acute glyceryl trinitrate (GTN)-induced headache, using imaging techniques such as transcranial Doppler (TCD), positron emission tomography (PET) and single photon emission computerized tomography (SPECT). In the present study we aimed to evaluate whether magnetic resonance angiography (MRA) may be used to examine the effect of GTN on the MCA, with respect to changes in diameter and cross-sectional area in healthy volunteers. In addition, we wanted to determine the intra- and inter-observer variation of the method. In a randomized, double blind, crossover study 12 healthy volunteers received intravenous infusion of GTN (0.5 microg/kg/min for 20 min) or placebo. Using 1.5 Tesla MRA, we recorded changes in the diameter and cross-sectional area of MCA before, during and after infusion of GTN. The MRA images were evaluated by two blinded, independent observers/neuroradiologists. The primary endpoints were the differences in the AUC for diameter and cross-sectional area of the MCA between the two experimental conditions and the intra- and inter-observer variation. The areas under the curve (AUC) of the MCA diameter and cross-sectional area were significantly greater after GTN than after placebo (P < 0.05). The intra-observer variation (day-to-day) at baseline was 8.3% and 10.9% for the two observers. The mean inter-observer variation of the cross-sectional MCA area was 15.5% and for the diameter measurements 8%. The present study shows that the MRA method gives a reliable semi-quantitative index of the vascular changes in the intra-cerebral arteries after infusion of GTN and may be useful for headache research.
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Affiliation(s)
- J M Hansen
- Danish Headache Centre, Department of Neurology, Glostrup Hospital, University of Copenhagen, Copenhagen, Denmark.
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9
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Box FMA, van der Grond J, de Craen AJM, Palm-Meinders IH, van der Geest RJ, Jukema JW, Reiber JHC, van Buchem MA, Blauw GJ. Pravastatin Decreases Wall Shear Stress and Blood Velocity in the Internal Carotid Artery Without Affecting Flow Volume. Stroke 2007; 38:1374-6. [PMID: 17332443 DOI: 10.1161/01.str.0000260206.56774.aa] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Despite speculations, it is unknown whether statins affect wall shear stress (WSS). Therefore, the effect of pravastatin on WSS was investigated.
Methods—
In 355 elderly individuals participating in the PROSPER study (follow up after 3 years), the effect of 40 mg pravastatin on WSS was assessed in the internal carotid artery using magnetic resonance imaging.
Results—
WSS and blood velocity decreased both in the pravastatin group and in the placebo group but decreased faster in the pravastatin group (
P
<0.04,
P
<0.02). Blood volume flow did not differ between the groups.
Conclusions—
In elderly subjects, the WSS and blood velocity of the internal carotid artery declines significantly over time and this decline is more pronounced in subjects treated with 40 mg pravastatin compared with the placebo group.
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Affiliation(s)
- Frieke M A Box
- Division of Image Processing, Leiden University Medical Center, Leiden, The Netherlands.
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10
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ten Dam VH, van den Heuvel DMJ, de Craen AJM, Bollen ELEM, Murray HM, Westendorp RGJ, Blauw GJ, van Buchem MA. Decline in Total Cerebral Blood Flow Is Linked with Increase in Periventricular but Not Deep White Matter Hyperintensities. Radiology 2007; 243:198-203. [PMID: 17329688 DOI: 10.1148/radiol.2431052111] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To retrospectively investigate the association between changes in total cerebral blood flow and progression of total, periventricular, and deep white matter hyperintensities over time. MATERIALS AND METHODS The institutional ethics review board approved the protocol for the prospective magnetic resonance (MR) imaging study, and all participants gave written informed consent. Participants also agreed to future retrospective analysis of their MR data for research purposes. In this substudy of the Prospective Study of Pravastatin in the Elderly at Risk, investigators performed a repeated MR imaging examination after an average interval of 33 months (standard deviation, 1.4) in 390 elderly men and women (ages 70-82 years at baseline) without dementia who were at high vascular risk. White matter hyperintensities were quantified with a semiautomatic method, and total cerebral blood flow was measured with a gradient-echo phase-contrast MR imaging technique. The association between total cerebral blood flow and volume of white matter hyperintensities was analyzed with logistic regression. RESULTS There was no association between baseline cerebral blood flow and prevalence of total, periventricular, or deep white matter hyperintensities at baseline MR imaging. Moreover, decline in cerebral blood flow was not associated with increase in total load of white matter hyperintensities. When the total volume of white matter hyperintensities was separated into periventricular and deep hyperintensities, for every 50 mL/min decrease in total cerebral blood flow there was a 1.32 (95% confidence interval: 1.06, 1.66; P = .015) increase in risk for developing periventricular white matter hyperintensities; there was no association, however, between decrease in total cerebral blood flow and risk of developing deep white matter hyperintensities (odds ratio, 1.00 [95% confidence interval: 0.79, 1.25]; P = .98). CONCLUSION Decline in total cerebral blood flow is associated with increase in volume of periventricular but not deep white matter hyperintensities.
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Affiliation(s)
- V Hester ten Dam
- Department of Gerontology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, the Netherlands
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11
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Box FMA, van der Geest RJ, van der Grond J, van Osch MJP, Zwinderman AH, Palm-Meinders IH, Doornbos J, Blauw GJ, van Buchem MA, Reiber JHC. Reproducibility of wall shear stress assessment with the paraboloid method in the internal carotid artery with velocity encoded MRI in healthy young individuals. J Magn Reson Imaging 2007; 26:598-605. [PMID: 17729354 DOI: 10.1002/jmri.21086] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To verify whether wall shear stress (WSS) can be assessed in a reproducible manner using automatic model-based segmentation of phase-contrast MR images by determination of flow volume and maximum flow velocity (Vmax) in cross-sections of these vessels. MATERIALS AND METHODS The approach is based on fitting a 3D paraboloid to the actual velocity profiles and on determining Vmax. WSS was measured in the internal carotid arteries of two groups of healthy young volunteers. The reproducibility of rescanning and repositioning was studied in the first group. In the second group a 1-week and a 1-month interval was investigated. Reproducibility was calculated by the intraclass correlation (ICC). RESULTS The flow volume, Vmax, and WSS averaged over the cardiac cycle were found to be 287.8 +/- 29.7 mL/min, 37.0 +/- 4.6 cm/s, and 1.13 +/- 0.16 Pa, respectively. The diastolic WSS varied between 1.00 +/- 0.21 Pa without averaging to 0.88 +/- 0.16 Pa with temporal and spatial averaging. Systolic WSS was 1.67 +/- 0.33 Pa without averaging and 1.67 +/- 0.25 Pa with averaging. ICC varied between 0.58 and 0.87 without averaging and between 0.75 and 0.90 with averaging for WSS. CONCLUSION WSS in MR images of the internal carotid artery can be assessed semiautomatically with good to excellent reproducibility without inter- or intraobserver variability using model-based postprocessing.
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Affiliation(s)
- Frieke M A Box
- Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
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12
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O'Gorman RL, Summers PE, Zelaya FO, Williams SCR, Alsop DC, Lythgoe DJ. In vivo estimation of the flow-driven adiabatic inversion efficiency for continuous arterial spin labeling: a method using phase contrast magnetic resonance angiography. Magn Reson Med 2006; 55:1291-7. [PMID: 16673361 DOI: 10.1002/mrm.20864] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The accurate quantification of perfusion with arterial spin labeling (ASL) requires consideration of a number of factors, including the efficiency of the inversion and control pulses used for spin labeling. In this study the effects of spin velocity on continuous ASL efficiency when using the amplitude modulated control strategy were investigated using simulations of the Bloch equations. The inversion efficiency was determined in vivo by combining the simulations with phase-contrast velocity mapping data acquired at the level of the tagging plane. Using this novel method, an average inversion efficiency of 69% was calculated for a group of 28 subjects, in good agreement with experimental data reported previously. There was, however, a large range in inversion efficiency measured across the subject group (50-76%), indicating that the velocity dependence of the amplitude modulated control efficiency may introduce additional variability into the perfusion calculations if not properly taken into account.
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Affiliation(s)
- Ruth L O'Gorman
- King's College London, Institute of Psychiatry, Centre for Neuroimaging Sciences, UK.
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13
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Kellenberger CJ, Macgowan CK, Roman KS, Al-Habshan F, Benson LN, Redington AN, Yoo SJ. Hemodynamic evaluation of the peripheral pulmonary circulation by cine phase-contrast magnetic resonance imaging. J Magn Reson Imaging 2005; 22:780-7. [PMID: 16270288 DOI: 10.1002/jmri.20447] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To describe the normal flow patterns in peripheral pulmonary vessels with phase-contrast (PC) magnetic resonance imaging (MRI). MATERIALS AND METHODS Twelve healthy adults (age = 33 +/- 7 years) underwent cine PC MRI of the segmental and central pulmonary arteries and veins by means of a breath-held segmented k-space technique. Flow patterns were analyzed on time-velocity curves and compared between the peripheral and central vessels. RESULTS The pulsatile flow patterns in the segmental arteries and veins were similar among individuals. When compared with the central pulmonary arteries, the segmental arteries had a delay in the systolic and diastolic flow velocity waves, and an increased magnitude of the diastolic peaks, in relation to the systolic peaks. A prominent notch was present during the deceleration phase of the systolic flow velocity wave in 79% of the segmental arteries investigated. The segmental veins showed a typical pulmonary venous flow pattern, as seen in the central veins, with similar systolic-to-diastolic peak velocity ratios. CONCLUSION Noninvasive evaluation of blood flow in intraparenchymal pulmonary vessels is feasible with PC MRI. This first description of normal flow patterns in segmental pulmonary arteries and veins can serve as basis for further investigation in the setting of altered pulmonary blood flows.
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Affiliation(s)
- Christian J Kellenberger
- Department of Diagnostic Imaging, Hospital for Sick Children, University of Toronto Faculty of Medicine, Toronto, Ontario, Canada
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14
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ten Dam VH, Box FMA, de Craen AJM, van den Heuvel DMJ, Bollen ELEM, Murray HM, van Buchem MA, Westendorp RGJ, Blauw GJ. Lack of Effect of Pravastatin on Cerebral Blood Flow or Parenchymal Volume Loss in Elderly at Risk for Vascular Disease. Stroke 2005; 36:1633-6. [PMID: 16049200 DOI: 10.1161/01.str.0000173162.88600.29] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Ageing is associated with a decline in cerebral blood flow. Animal studies have shown that cholesterol-lowering therapy with statins might preserve cerebral blood flow (CBF). We examined the effect of 40 mg pravastatin on the decline in CBF and brain volume in a subset of elderly subjects participating in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) trial.
Methods—
Randomization was not stratified according to whether or not subjects participated in the MRI substudy. In 391 men (n=226) and women (n=165) aged 70 to 82 years (mean±SD, 75±3.2), we measured total CBF (in mL/min) at baseline and after a mean±SD follow-up of 33±1.4 months with a gradient-echo phase-contrast MRI technique. Total CBF was defined as the summed flows in both internal carotid and vertebral arteries. Parenchymal volume (whole brain) was segmented with the use of in-house–developed semiautomatic software.
Results—
Total CBF significantly declined in the placebo-allocated group, from 521±83 to 504±92 mL/min (
P
=0.0036) and in the pravastatin-allocated group from 520±94 to 506±92 mL/min (
P
=0.018). This decline was not significantly different between treatment groups (
P
=0.56). There was also a significant reduction in brain volume over time (
P
<0.001), which was not different between the treatment groups (
P
=0.47). When expressed per unit of parenchymal volume, the decline in CBF over time was no longer statistically significant.
Conclusions—
Elderly people at risk for cerebral vascular disease had a significant decline in CBF with increasing age that was explained by a concomitant reduction in brain volume. Treatment with 40 mg pravastatin daily had no beneficial effect on total CBF.
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Affiliation(s)
- V Hester ten Dam
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
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15
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Box FMA, van der Geest RJ, Rutten MCM, Reiber JHC. The Influence of Flow, Vessel Diameter, and Non-Newtonian Blood Viscosity on the Wall Shear Stress in a Carotid Bifurcation Model for Unsteady Flow. Invest Radiol 2005; 40:277-94. [PMID: 15829825 DOI: 10.1097/01.rli.0000160550.95547.22] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The atherosclerotic process in arteries is correlated with the local wall shear stress (WSS). Plaque development particularly occurs in regions with recirculation (ie, where the WSS oscillates). We investigated the effects of non-Newtonian blood viscosity, variations in flow rate, and vessel diameter on wall phenomena in a carotid bifurcation model. MATERIALS AND METHODS The flow through a model of a carotid artery bifurcation was simulated by means of the finite element method. The whole-blood viscosity is a function of shear rate, and was modeled by the Carreau-Yasuda (CY) model. Flow rate and vessel morphology were assessed with magnetic resonance imaging. Flow rate, blood viscosity, and hematocrit levels (Hct) were measured in 49 healthy volunteers. We propose an adaptation of the CY model so that differences in Hct can be incorporated; furthermore, plasma viscosity was varied in the CY model. RESULTS The data from our model indicate that flow increases have a larger effect on the WSS than predicted with a simple paraboloid model. Hct had more influence on the WSS when the plasma viscosity was low. Low plasma viscosity was associated with a low WSS, which implies a contradiction, because both high WSS and low plasma viscosity are thought to be indicators for a healthy system. Maximum WSS oscillations were found at the edges of the recirculation region. CONCLUSIONS Flow and diameter changes have significant influence on wall shear stress values; the same is true for the viscosity, but to a lesser extent.
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Affiliation(s)
- Frieke M A Box
- Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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Coffi SB, Ubbink DT, Legemate DA. Noninvasive Techniques to Detect Subcritical Iliac Artery Stenoses. Eur J Vasc Endovasc Surg 2005; 29:305-7. [PMID: 15694806 DOI: 10.1016/j.ejvs.2004.12.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2004] [Indexed: 11/30/2022]
Affiliation(s)
- S B Coffi
- Department of Vascular Surgery, Academic Medical Center, Amsterdam, The Netherlands
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Runge VM. Advances in magnetic resonance. Invest Radiol 2004; 39:713-6. [PMID: 15550831 DOI: 10.1097/00004424-200412000-00001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Val M Runge
- Department of Radiology, Scott and White Clinic and Hospital, Temple, Texas 76508, USA.
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