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Naber A, Reiß M, Nahm W. Transit Time Measurement in Indicator Dilution Curves: Overcoming the Missing Ground Truth and Quantifying the Error. Front Physiol 2021; 12:588120. [PMID: 34122123 PMCID: PMC8194354 DOI: 10.3389/fphys.2021.588120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
The vascular function of a vessel can be qualitatively and intraoperatively checked by recording the blood dynamics inside the vessel via fluorescence angiography (FA). Although FA is the state of the art in proving the existence of blood flow during interventions such as bypass surgery, it still lacks a quantitative blood flow measurement that could decrease the recurrence rate and postsurgical mortality. Previous approaches show that the measured flow has a significant deviation compared to the gold standard reference (ultrasonic flow meter). In order to systematically address the possible sources of error, we investigated the error in transit time measurement of an indicator. Obtaining in vivo indicator dilution curves with a known ground truth is complex and often not possible. Further, the error in transit time measurement should be quantified and reduced. To tackle both issues, we first computed many diverse indicator dilution curves using an in silico simulation of the indicator's flow. Second, we post-processed these curves to mimic measured signals. Finally, we fitted mathematical models (parabola, gamma variate, local density random walk, and mono-exponential model) to re-continualize the obtained discrete indicator dilution curves and calculate the time delay of two analytical functions. This re-continualization showed an increase in the temporal accuracy up to a sub-sample accuracy. Thereby, the Local Density Random Walk (LDRW) model performed best using the cross-correlation of the first derivative of both indicator curves with a cutting of the data at 40% of the peak intensity. The error in frames depends on the noise level and is for a signal-to-noise ratio (SNR) of 20 dB and a sampling rate of fs = 60 Hz at fs-1·0.25(±0.18), so this error is smaller than the distance between two consecutive samples. The accurate determination of the transit time and the quantification of the error allow the calculation of the error propagation onto the flow measurement. Both can assist surgeons as an intraoperative quality check and thereby reduce the recurrence rate and post-surgical mortality.
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Affiliation(s)
- Ady Naber
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Michael Reiß
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Werner Nahm
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany
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Cortical thinning is associated with brain pulsatility in older adults: An MRI and NIRS study. Neurobiol Aging 2021; 106:103-118. [PMID: 34274697 DOI: 10.1016/j.neurobiolaging.2021.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 03/29/2021] [Accepted: 05/03/2021] [Indexed: 11/21/2022]
Abstract
Aging is accompanied by global brain atrophy occurring unequally across the brain. Cortical thinning is seen with aging with a larger loss in the frontal and temporal subregions. We explored the link between regional cortical thickness and regional cerebral pulsatility. Sixty healthy individuals were divided into two age groups, young (aged 19-31) and older (aged 65-75) adults. Each participant underwent a near-infrared spectroscopy (NIRS) scan to index regional brain pulsatility from cerebral pulse-transit-time-to-the peak-of-the-pulse (PTTp), an anatomical magnetic resonance imaging (MRI) and a phase-contrast MRI (PC-MRI) scan to measure arterial and cerebrospinal fluid (CSF) pulsatility. In older adults, the greatest association between cerebral pulsatility and cortical thickness was found in superior and middle temporal and superior, middle and inferior frontal areas, which are the regions perfused first by the internal carotid arteries. This association dropped in the postcentral and superior parietal regions. These findings suggest higher brain pulsatility as a potential risk factor contributing to cortical thinning for some brain regions more than others.
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53
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van Hespen KM, Kuijf HJ, Hendrikse J, Luijten PR, Zwanenburg JJM. Blood Flow Velocity Pulsatility and Arterial Diameter Pulsatility Measurements of the Intracranial Arteries Using 4D PC-MRI. Neuroinformatics 2021; 20:317-326. [PMID: 34019208 PMCID: PMC9546978 DOI: 10.1007/s12021-021-09526-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2021] [Indexed: 10/28/2022]
Abstract
4D phase contrast magnetic resonance imaging (PC-MRI) allows for the visualization and quantification of the cerebral blood flow. A drawback of software that is used to quantify the cerebral blood flow is that it oftentimes assumes a static arterial luminal area over the cardiac cycle. Quantifying the lumen area pulsatility index (aPI), i.e. the change in lumen area due to an increase in distending pressure over the cardiac cycle, can provide insight in the stiffness of the arteries. Arterial stiffness has received increased attention as a predictor in the development of cerebrovascular disease. In this study, we introduce software that allows for measurement of the aPI as well as the blood flow velocity pulsatility index (vPI) from 4D PC-MRI. The internal carotid arteries of seven volunteers were imaged using 7 T MRI. The aPI and vPI measurements from 4D PC-MRI were validated against measurements from 2D PC-MRI at two levels of the internal carotid arteries (C3 and C7). The aPI and vPI computed from 4D PC-MRI were comparable to those measured from 2D PC-MRI (aPI: mean difference: 0.03 (limits of agreement: -0.14 - 0.23); vPI: 0.03 (-0.17-0.23)). The measured blood flow rate for the C3 and C7 segments was similar, indicating that our proposed software correctly captures the variation in arterial lumen area and blood flow velocity that exists along the distal end of the carotid artery. Our software may potentially aid in identifying changes in arterial stiffness of the intracranial arteries caused by pathological changes to the vessel wall.
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Affiliation(s)
| | - Hugo J Kuijf
- Image Sciences Institute, UMC Utrecht, Utrecht, The Netherlands
| | | | - Peter R Luijten
- Department of Radiology, UMC Utrecht, Utrecht, The Netherlands
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54
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Lefferts WK, Lefferts EC, Hibner BA, Smith KJ, Fernhall B. Impact of acute changes in blood pressure and arterial stiffness on cerebral pulsatile haemodynamics in young and middle-aged adults. Exp Physiol 2021; 106:1643-1653. [PMID: 33938052 DOI: 10.1113/ep089319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 04/28/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does cerebrovascular pulsatility respond differently to acute increases in arterial stiffness in middle-aged compared with young adults? What is the main finding and its importance? Compared with young adults, middle-aged adults exhibited similar changes in cerebral pulsatile damping despite attenuated changes in carotid diameter and cerebrovascular pulsatility during blood pressure-dependent, but not blood pressure-independent, increases in large artery stiffness. ABSTRACT Acute manipulation of arterial stiffness through interventions that increase sympathetic activity might provoke cerebral pulsatility and damping and reveal whether cerebrovascular haemodynamics respond differently to transient elevations in arterial stiffness in middle-aged compared with young adults. We compared cerebral pulsatility and damping in middle-aged versus young adults during two different sympathetic interventions [cold pressor test (CP) and lower-body negative pressure (LBNP)] that increase arterial stiffness acutely. Cerebrovascular haemodynamics were assessed in 15 middle-aged (54 ± 7 years old; 11 female) and 15 sex-matched young adults (25 ± 4 years old) at rest and during the CP test (4 min, 6.4 ± 0.8°C) and LBNP (6 min, -20 mmHg). Mean blood pressure was measured continuously via finger photoplethysmography. Carotid-femoral pulse wave velocity (cfPWV) and carotid stiffness were measured via tonometry and ultrasound. Blood velocity pulsatility index (PI) was measured at the middle cerebral (MCA) and common carotid artery (CCA) using Doppler, with pulsatile damping calculated as CCA PI divided by MCA PI. Increases in cfPWV were driven by changes in mean pressure during CP but not during LBNP in both groups (P < 0.05). Pulsatile damping decreased in both groups (P < 0.05) despite reductions in MCA PI and greater carotid dilatation during CP in young compared with middle-aged adults (P < 0.05). Pressure-independent increases in cfPWV during LBNP did not alter pulsatile damping but decreased MCA PI in both young and middle-aged adults (P < 0.05). These data suggest that changes in carotid diameter and cerebrovascular pulsatility differ between young and middle-aged adults despite similar changes in cerebral pulsatile damping during blood pressure-dependent, but not blood pressure-independent, increases in large artery stiffness.
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Affiliation(s)
- Wesley K Lefferts
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Kinesiology, Iowa State University, Ames, Iowa, USA
| | - Elizabeth C Lefferts
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Brooks A Hibner
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Kurt J Smith
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Bo Fernhall
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA
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55
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Arts T, Meijs TA, Grotenhuis H, Voskuil M, Siero J, Biessels GJ, Zwanenburg J. Velocity and Pulsatility Measures in the Perforating Arteries of the Basal Ganglia at 3T MRI in Reference to 7T MRI. Front Neurosci 2021; 15:665480. [PMID: 33981198 PMCID: PMC8107291 DOI: 10.3389/fnins.2021.665480] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/06/2021] [Indexed: 11/28/2022] Open
Abstract
Cerebral perforating artery flow velocity and pulsatility can be measured using 7 tesla (T) MRI. Enabling these flow metrics on more widely available 3T systems would make them more employable. It is currently unknown whether these measurements can be performed at 3T MRI due to the lower signal-to-noise ratio (SNR). Therefore, the aim of this study is to investigate if flow velocity and pulsatility in the perforating arteries of the basal ganglia (BG) can be measured at 3T MRI and assess the agreement with 7T MRI measurements as reference. Twenty-nine subjects were included, of which 14 patients with aortic coarctation [median age 29 years (21–72)] and 15 controls [median age 27 years (22–64)]. Using a cardiac-gated 2D phase-contrast MRI sequence BG perforating arteries were imaged at 3T and 7T MRI and perforating artery density (Ndensity, #/cm2), flow velocity (Vmean, cm/s) and pulsatility index (PI) were determined. Agreement between scanner modalities was assessed using correlation and difference plots with linear regression. A p-value ≤ 0.05 indicated statistical significance. It was shown that perforating artery flow velocity and pulsatility can be measured at 3T MRI (Ndensity = 0.21 ± 0.11; Vmean = 6.04 ± 1.27; PI = 0.49 ± 0.19), although values differed from 7T MRI measurements (Ndensity = 0.95 ± 0.21; Vmean = 3.89 ± 0.56; PI = 0.28 ± 0.08). The number of detected arteries was lower at 3T (5 ± 3) than 7T MRI (24 ± 6), indicating that 3T MRI is on average a factor 4.8 less sensitive to detect cerebral perforating arteries. Comparison with 7T MRI as reference showed some agreement in Ndensity, but little to no agreement for Vmean and PI. Equalizing the modalities’ sensitivity by comparing the detected arteries on 7T MRI with the highest velocity with all vessels detected on 3T MRI, showed some improvement in agreement for PI, but not for Vmean. This study shows that it is possible to measure cerebral perforating artery flow velocity and pulsatility at 3T MRI, although an approximately fivefold sample size is needed at 3T relative to 7T MRI for a given effect size, and the measurements should be performed with equal scanner field strength and protocol.
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Affiliation(s)
- Tine Arts
- Department of Radiology, Center for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands
| | - Timion A Meijs
- Department of Cardiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Heynric Grotenhuis
- Department of Pediatric Cardiology, University Medical Center Utrecht - Wilhelmina Children's Hospital, Utrecht, Netherlands
| | - Michiel Voskuil
- Department of Cardiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Jeroen Siero
- Department of Radiology, Center for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands.,Spinoza Center for Neuroimaging, Amsterdam, Netherlands
| | - Geert Jan Biessels
- Department of Neurology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Jaco Zwanenburg
- Department of Radiology, Center for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands
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56
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Vikner T, Nyberg L, Holmgren M, Malm J, Eklund A, Wåhlin A. Characterizing pulsatility in distal cerebral arteries using 4D flow MRI. J Cereb Blood Flow Metab 2020; 40:2429-2440. [PMID: 31722598 PMCID: PMC7820688 DOI: 10.1177/0271678x19886667] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Recent reports have suggested that age-related arterial stiffening and excessive cerebral arterial pulsatility cause blood-brain barrier breakdown, brain atrophy and cognitive decline. This has spurred interest in developing non-invasive methods to measure pulsatility in distal vessels, closer to the cerebral microcirculation. Here, we report a method based on four-dimensional (4D) flow MRI to estimate a global composite flow waveform of distal cerebral arteries. The method is based on finding and sampling arterial waveforms from thousands of cross sections in numerous small vessels of the brain, originating from cerebral cortical arteries. We demonstrate agreement with internal and external reference methods and show the ability to capture significant increases in distal cerebral arterial pulsatility as a function of age. The proposed approach can be used to advance our understanding regarding excessive arterial pulsatility as a potential trigger of cognitive decline and dementia.
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Affiliation(s)
- Tomas Vikner
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
- Tomas Vikner, Department of Radiation Sciences, Umeå University, Umeå SE 901 87, Sweden.
| | - Lars Nyberg
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
- Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
| | | | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
| | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
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57
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Lefferts WK, DeBlois JP, Augustine JA, Keller AP, Heffernan KS. Age, sex, and the vascular contributors to cerebral pulsatility and pulsatile damping. J Appl Physiol (1985) 2020; 129:1092-1101. [PMID: 32940561 PMCID: PMC7790130 DOI: 10.1152/japplphysiol.00500.2020] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cerebral pulsatility reflects a balance between the transmission and damping of pulsatility in the cerebrovasculature. Females experience greater cerebral pulsatility with aging, which may have implications for sex differences in stroke risk and cognitive decline. This study sought to explore vascular contributors to cerebral pulsatility and pulsatile damping in men and women. Adults (n = 282, 53% female) underwent measurements of cerebral (middle cerebral artery) pulsatility, pulsatile damping (ratio of cerebral to carotid pulsatility), large artery stiffening (ratio of aortic to carotid pulse wave velocity), and carotid wave transmission/reflection dynamics using wave intensity analysis. Multiple regression revealed that older age, female sex, greater large artery stiffening, higher carotid pulse pressure, and greater forward wave energy was associated with increased cerebral pulsatility (adjusted R2 = 0.44, P < 0.05). Contributors to decreased cerebral pulsatile damping included older age, female sex, and lower wave reflection index (adjusted R2 = 0.51, P < 0.05). Our data link greater large artery stiffening, carotid pulse pressure, and forward wave energy to greater cerebral pulsatility, while greater carotid wave reflection may enhance cerebral pulsatile damping. Lower cerebral pulsatile damping among females may contribute to greater age-associated cerebral pulsatile burden compared with males. NEW & NOTEWORTHY Cerebral pulsatility contributes to brain health and depends on a balance between transmission and damping of pulsatile hemodynamics into the cerebrovasculature. Our data indicate that cerebral pulsatility increases with age, female sex, extracranial artery stiffening, forward wave energy, and pulse pressure, whereas pulsatile damping decreases with age and female sex and increases with greater carotid wave reflections. These novel data identify pulsatile damping as a potential contributor to sex differences in cerebral pulsatile burden.
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Affiliation(s)
- Wesley K Lefferts
- Department of Exercise Science, Syracuse University, Syracuse, New York.,Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.,Department of Kinesiology, Iowa State University, Ames, Iowa
| | - Jacob P DeBlois
- Department of Exercise Science, Syracuse University, Syracuse, New York
| | - Jacqueline A Augustine
- Department of Exercise Science, Syracuse University, Syracuse, New York.,Department of Kinesiology, SUNY Cortland, Cortland, New York
| | - Allison P Keller
- Department of Exercise Science, Syracuse University, Syracuse, New York
| | - Kevin S Heffernan
- Department of Exercise Science, Syracuse University, Syracuse, New York
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58
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van Tuijl RJ, Ruigrok YM, Velthuis BK, van der Schaaf IC, Rinkel GJE, Zwanenburg JJM. Velocity Pulsatility and Arterial Distensibility Along the Internal Carotid Artery. J Am Heart Assoc 2020; 9:e016883. [PMID: 32783485 PMCID: PMC7660833 DOI: 10.1161/jaha.120.016883] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Attenuation of velocity pulsatility along the internal carotid artery (ICA) is deemed necessary to protect the microvasculature of the brain. The role of the carotid siphon within the whole ICA trajectory in pulsatility attenuation is still poorly understood. This study aims to assess arterial variances in velocity pulsatility and distensibility over the whole ICA trajectory, including effects of age and sex. Methods and Results We assessed arterial velocity pulsatility and distensibility using flow-sensitized 2-dimensional phase-contrast 3.0 Tesla magnetic resonance imaging in 118 healthy participants. Velocity pulsatility index (vPI=(Vmax-Vmin)/Vmean) and arterial distensibility defined as area pulsatility index (Amax-Amin)/Amean) were calculated at C1, C3, and C7 segments of the ICA. vPI increased between C1 and C3 (0.85±0.13 versus 0.93±0.13, P<0.001 for averaged right+left ICA) and decreased between C3 and C7 (0.93±0.13 versus 0.84±0.13, P<0.001) with overall no effect (C1-C7). Conversely, the area pulsatility index decreased between C1 and C3 (0.18±0.06 versus 0.14±0.04, P<0.001) and increased between C3 and C7 (0.14±0.04 versus 0.31±0.09, P<0.001). vPI in men is higher than in women and increases with age (P<0.015). vPI over the carotid siphon declined with age but remained stable over the whole ICA trajectory. Conclusions Along the whole ICA trajectory, vPI increased from extracranial C1 up to the carotid siphon C3 with overall no effect on vPI between extracranial C1 and intracranial C7 segments. This suggests that the bony carotid canal locally limits the arterial distensibility of the ICA, increasing the vPI at C3 which is consequently decreased again over the carotid siphon. In addition, vPI in men is higher and increases with age.
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Affiliation(s)
- Rick J van Tuijl
- Department of Radiology University Medical Center Utrecht Utrecht The Netherlands
| | - Ynte M Ruigrok
- Department of Neurology and Neurosurgery Rudolf Magnus Institute of Neuroscience University Medical Center Utrecht Utrecht The Netherlands
| | - Birgitta K Velthuis
- Department of Radiology University Medical Center Utrecht Utrecht The Netherlands
| | | | - Gabriël J E Rinkel
- Department of Neurology and Neurosurgery Rudolf Magnus Institute of Neuroscience University Medical Center Utrecht Utrecht The Netherlands
| | - Jaco J M Zwanenburg
- Department of Radiology University Medical Center Utrecht Utrecht The Netherlands
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59
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Najafi M, Cancelliere NM, Brina O, Bouillot P, Vargas MI, Delattre BM, Pereira VM, Steinman DA. How patient-specific do internal carotid artery inflow rates need to be for computational fluid dynamics of cerebral aneurysms? J Neurointerv Surg 2020; 13:459-464. [PMID: 32732256 DOI: 10.1136/neurintsurg-2020-015993] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 11/03/2022]
Abstract
BACKGROUND Computational fluid dynamics (CFD) has become a popular tool for studying 'patient-specific' blood flow dynamics in cerebral aneurysms; however, rarely are the inflow boundary conditions patient-specific. We aimed to test the impact of widespread reliance on generalized inflow rates. METHODS Internal carotid artery (ICA) flow rates were measured via 2D cine phase-contrast MRI for 24 patients scheduled for endovascular therapy of an ICA aneurysm. CFD models were constructed from 3D rotational angiography, and pulsatile inflow rates imposed as measured by MRI or estimated using an average older-adult ICA flow waveform shape scaled by a cycle-average flow rate (Qavg) derived from the patient's ICA cross-sectional area via an assumed inlet velocity. RESULTS There was good overall qualitative agreement in the magnitudes and spatial distributions of time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and spectral power index (SPI) using generalized versus patient-specific inflows. Sac-averaged quantities showed moderate to good correlations: R2=0.54 (TAWSS), 0.80 (OSI), and 0.68 (SPI). Using patient-specific Qavg to scale the generalized waveform shape resulted in near-perfect agreement for TAWSS, and reduced bias, but not scatter, for SPI. Patient-specific waveform had an impact only on OSI correlations, which improved to R2=0.93. CONCLUSIONS Aneurysm CFD demonstrates the ability to stratify cases by nominal hemodynamic 'risk' factors when employing an age- and vascular-territory-specific recipe for generalized inflow rates. Qavg has a greater influence than waveform shape, suggesting some improvement could be achieved by including measurement of patient-specific Qavg into aneurysm imaging protocols.
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Affiliation(s)
- Mehdi Najafi
- Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Nicole M Cancelliere
- Joint Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Olivier Brina
- Department for Diagnostic and Interventional Neuroradiology, Hôpitaux Universitaires de Geneve, Geneva, Switzerland
| | - Pierre Bouillot
- Department for Diagnostic and Interventional Neuroradiology, Hôpitaux Universitaires de Geneve, Geneva, Switzerland
| | - Maria I Vargas
- Department for Diagnostic and Interventional Neuroradiology, Hôpitaux Universitaires de Geneve, Geneva, Switzerland
| | - Benedicte Ma Delattre
- Department for Diagnostic and Interventional Neuroradiology, Hôpitaux Universitaires de Geneve, Geneva, Switzerland
| | - Vitor M Pereira
- Joint Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada
- Department of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada
| | - David A Steinman
- Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Ontario, Canada
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60
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Chodzyǹski KJ, Uzureau P, Nuyens V, Rousseau A, Coussement G, Zouaoui Boudjeltia K. The impact of arterial flow complexity on flow diverter outcomes in aneurysms. Sci Rep 2020; 10:10337. [PMID: 32587308 PMCID: PMC7316819 DOI: 10.1038/s41598-020-67218-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/28/2020] [Indexed: 12/03/2022] Open
Abstract
The flow diverter is becoming a standard device for treating cerebral aneurysms. The aim of this in vitro study was to evaluate the impact of flow complexity on the effectiveness of flow diverter stents in a cerebral aneurysm model. The flow pattern of a carotid artery was decomposed into harmonics to generate four flow patterns with different pulsatility indexes ranging from 0.72 to 1.44. The effect of flow diverters on the aneurysm was investigated by injecting red dye or erythrocytes as markers. The recorded images were postprocessed to evaluate the maximum filling of the aneurysm cavity and the washout time. There were significant differences in the cut-off flows between the markers, linked to the flow complexity. Increasing the pulsatility index altered the performance of the flow diverter. The red dye was more sensitive to changes in flow than the red blood cell markers. The flow cut-off depended on the diverter design and the diverter deployment step was crucial for reproducibility of the results. These results strongly suggest that flow complexity should be considered when selecting a flow diverter.
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Affiliation(s)
- Kamil Jerzy Chodzyǹski
- Laboratoire de Médecine Expérimentale (ULB222), CHU Charleroi, Université Libre de Bruxelles, 6110, Montigny le Tilleul, Belgium.
| | - Pierrick Uzureau
- Laboratoire de Médecine Expérimentale (ULB222), CHU Charleroi, Université Libre de Bruxelles, 6110, Montigny le Tilleul, Belgium
| | - Vincent Nuyens
- Laboratoire de Médecine Expérimentale (ULB222), CHU Charleroi, Université Libre de Bruxelles, 6110, Montigny le Tilleul, Belgium
| | - Alexandre Rousseau
- Laboratoire de Médecine Expérimentale (ULB222), CHU Charleroi, Université Libre de Bruxelles, 6110, Montigny le Tilleul, Belgium
| | | | - Karim Zouaoui Boudjeltia
- Laboratoire de Médecine Expérimentale (ULB222), CHU Charleroi, Université Libre de Bruxelles, 6110, Montigny le Tilleul, Belgium
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61
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Holwerda SW, Kardon RH, Hashimoto R, Full JM, Nellis JK, DuBose LE, Fiedorowicz JG, Pierce GL. Aortic stiffness is associated with changes in retinal arteriole flow pulsatility mediated by local vasodilation in healthy young/middle-age adults. J Appl Physiol (1985) 2020; 129:84-93. [PMID: 32437246 DOI: 10.1152/japplphysiol.00252.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Aortic stiffness is associated with augmented pressure pulsatility in large conduit arteries and remodeling of the microcirculation. However, studies in humans examining the relation between aortic stiffness and end-organ microvascular flow pulsatility are limited. Therefore, we used the retinal microvasculature as an end-organ in vivo model to examine the hypothesis that aortic stiffness would be positively associated with microvascular flow pulsatility index (PI) (flow pulse amplitude/mean flow) in humans. In 40 young/middle-age healthy adults (25-60 yr old, 50% women), aortic stiffness (carotid-femoral pulse wave velocity, CFPWV) and retinal arteriole flow (laser speckle flowgraphy) were examined at rest and during metabolic vasodilation (light flicker). CFPWV and related increases in central pulse pressure (PP) were inversely correlated with arteriole lumen diameter independent of age (CFPWV: R = -0.52, P = 0.001; Central PP: R = -0.39, P = 0.014). Accordingly, microvascular resistance was positively related to CFPWV independent of age (R = 0.35, P = 0.031). Multiple linear regression showed that CFPWV was not a significant determinant of resting arteriole flow PI (β = -0.10, P = 0.64). However, during reduced retinal microvascular resistance using light flicker (P < 0.001), CFPWV was a significant determinant of the percent change in arteriole flow PI (β = 0.58, P = 0.046), but not mean flow (β = -0.17, P = 0.54), where reductions in arteriole flow PI were associated with lower CFPWV. In summary, our findings suggest that higher aortic stiffness and the related increase in central PP in healthy young/middle-age adults are associated with retinal arteriole narrowing and smaller reductions in arteriole flow pulsatility in response to dynamic conditions such as local metabolic vasodilation.NEW & NOTEWORTHY By using the human retinal microvasculature as an end-organ in vivo model, we confirm that aortic stiffness and related increases in central pulse pressure are inversely correlated with retinal arteriole lumen diameter and increased microvascular resistance among heathy young/middle-age adults. Additionally, higher aortic stiffness is not associated with excessive flow pulsatility in the retinal microvasculature under tonic conditions but may be related to limited reductions in retinal arteriole flow pulsatility in response to local vasodilation.
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Affiliation(s)
- Seth W Holwerda
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa.,Abboud Cardiovascular Research Center, University of Iowa, Iowa City, Iowa.,Department of Anesthesiology, University of Kansas Medical Center, Kansas City, Kansas
| | - Randy H Kardon
- Iowa City Veterans Affairs Center for Prevention and Treatment of Visual Loss, Iowa City, Iowa.,Department of Veteran Affairs Hospital Iowa City, Iowa City, Iowa.,Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa
| | - Ryuya Hashimoto
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa
| | - Jan M Full
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa
| | - Julie K Nellis
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa
| | - Lyndsey E DuBose
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Jess G Fiedorowicz
- Abboud Cardiovascular Research Center, University of Iowa, Iowa City, Iowa.,Department of Psychiatry, University of Iowa, Iowa City, Iowa.,Department of Epidemiology, University of Iowa, Iowa City, Iowa.,Department of Internal Medicine, University of Iowa, Iowa City, Iowa
| | - Gary L Pierce
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa.,Abboud Cardiovascular Research Center, University of Iowa, Iowa City, Iowa
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de Montgolfier O, Thorin-Trescases N, Thorin E. Pathological Continuum From the Rise in Pulse Pressure to Impaired Neurovascular Coupling and Cognitive Decline. Am J Hypertens 2020; 33:375-390. [PMID: 32202623 PMCID: PMC7188799 DOI: 10.1093/ajh/hpaa001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 12/11/2019] [Accepted: 03/03/2020] [Indexed: 12/12/2022] Open
Abstract
The "biomechanical hypothesis" stipulates that with aging, the cumulative mechanical damages to the cerebral microvasculature, magnified by risk factors for vascular diseases, contribute to a breach in cerebral homeostasis producing neuronal losses. In other words, vascular dysfunction affects brain structure and function, and leads to cognitive failure. This is gathered under the term Vascular Cognitive Impairment and Dementia (VCID). One of the main culprits in the occurrence of cognitive decline could be the inevitable rise in arterial pulse pressure due to the age-dependent stiffening of large conductance arteries like the carotids, which in turn, could accentuate the penetration of the pulse pressure wave deeper into the fragile microvasculature of the brain and damage it. In this review, we will discuss how and why the vascular and brain cells communicate and are interdependent, describe the deleterious impact of a vascular dysfunction on brain function in various neurodegenerative diseases and even of psychiatric disorders, and the potential chronic deleterious effects of the pulsatile blood pressure on the cerebral microcirculation. We will also briefly review data from antihypertensive clinical trial aiming at improving or delaying dementia. Finally, we will debate how the aging process, starting early in life, could determine our sensitivity to risk factors for vascular diseases, including cerebral diseases, and the trajectory to VCID.
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Affiliation(s)
- Olivia de Montgolfier
- Faculty of Medicine, Department of Pharmacology and Physiology, Université de Montréal, Montreal, Quebec, Canada
- Montreal Heart Institute, Research Center, Montreal, Quebec, Canada
| | | | - Eric Thorin
- Faculty of Medicine, Department of Pharmacology and Physiology, Université de Montréal, Montreal, Quebec, Canada
- Montreal Heart Institute, Research Center, Montreal, Quebec, Canada
- Faculty of Medicine, Department of Surgery, Université de Montréal, Montreal, Quebec, Canada
- Correspondence: Eric Thorin ()
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63
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Rosenberg AJ, Schroeder EC, Grigoriadis G, Wee SO, Bunsawat K, Heffernan KS, Fernhall B, Baynard T. Aging reduces cerebral blood flow regulation following an acute hypertensive stimulus. J Appl Physiol (1985) 2020; 128:1186-1195. [PMID: 32240012 DOI: 10.1152/japplphysiol.00137.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Aging increases arterial stiffness, which has a negative impact on cerebral blood flow (CBF) regulation (decreases CBF and increases CBF pulsatility). The association between arterial stiffness and CBF pulsatility may, in part, explain the relationship between elevated blood pressure (BP) fluctuations and end-organ disease with aging. To understand the mechanisms by which large BP alterations influence cerebral blood flow regulation in both young and old, we examined the effects of age on central and cerebral blood flow regulation following an acute hypertensive stimulus [resistance-exercise (RE)]. Measurements were obtained pre and immediately, 5, and 30 min post-RE in young (n = 35) and older (n = 26) adults. Measurements included cerebral blood velocity (CBv), CBv pulsatility, central pulse-wave velocity (PWV), beta-stiffness index (β), and carotid blood flow pulsatility. Central hemodynamics and BP were continuously recorded. Mean CBv increased immediately post-RE only in the young and decreased below baseline at 5 min post-RE in both groups (interaction, P < 0.05). Older adults had a greater increase in CBv pulsatility immediately post-RE compared with the young (interaction, P < 0.05). Mean BP was higher and carotid pulsatility was lower in the older group and increased immediately post-RE in both groups (P < 0.05). PWV increased immediately post-RE (P < 0.05). There were no changes in β. In conclusion, with aging, greater central arterial stiffness leads to a greater transmission of pulsatile blood velocity from the systemic circulation to the cerebral circulation following an acute hypertensive stress.NEW & NOTEWORTHY Reductions in cerebral blood flow and increases in flow pulsatility with aging are associated to cerebrovascular disease; however, little is known about how an acute hypertensive stimulus effects cerebral blood flow regulation in an aged population. Following the hypertensive stimulus, older adults elicit an attenuated increase in cerebral blood velocity and greater transmission of pulsatile velocity to the brain compared with young adults, demonstrating reduced cerebral blood flow regulation to elevated blood pressure responses with aging.
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Affiliation(s)
- Alexander J Rosenberg
- Department of Kinesiology and Nutrition, Integrative Physiology Laboratory, University of Illinois, Chicago, Illinois
| | - Elizabeth C Schroeder
- Department of Kinesiology and Nutrition, Integrative Physiology Laboratory, University of Illinois, Chicago, Illinois
| | - Georgios Grigoriadis
- Department of Kinesiology and Nutrition, Integrative Physiology Laboratory, University of Illinois, Chicago, Illinois
| | - Sang Ouk Wee
- Department of Kinesiology and Nutrition, Integrative Physiology Laboratory, University of Illinois, Chicago, Illinois.,Department of Kinesiology, California State University, San Bernardino, California
| | - Kanokwan Bunsawat
- Department of Kinesiology and Nutrition, Integrative Physiology Laboratory, University of Illinois, Chicago, Illinois.,Department of Internal Medicine, Division of Geriatrics, University of Utah; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Kevin S Heffernan
- Department of Exercise Science, Human Performance Laboratory, Syracuse University, Syracuse, New York
| | - Bo Fernhall
- Department of Kinesiology and Nutrition, Integrative Physiology Laboratory, University of Illinois, Chicago, Illinois
| | - Tracy Baynard
- Department of Kinesiology and Nutrition, Integrative Physiology Laboratory, University of Illinois, Chicago, Illinois
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Extracranial versus intracranial hydro-hemodynamics during aging: a PC-MRI pilot cross-sectional study. Fluids Barriers CNS 2020; 17:1. [PMID: 31931818 PMCID: PMC6958565 DOI: 10.1186/s12987-019-0163-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 12/19/2019] [Indexed: 12/04/2022] Open
Abstract
Background Both aging and changes in blood flow velocity between the extracranial (intraspinal) and intracranial regions of cerebral vessels have an impact on brain hydro-hemodynamics. Arterial and venous cerebral blood flows interact with cerebrospinal fluid (CSF) in the both the cranial and spinal systems. Studies suggest that increased blood and CSF flow pulsatility plays an important role in certain neurological diseases. Here, we investigated the changes in blood-CSF flow pulsatility in the cranial and spinal systems with age as well as the impact of the intracranial compartment on flow patterns. Method Phase-contrast magnetic resonance imaging (PC-MRI) was performed in 16 young and 19 elderly healthy volunteers to measure the flows of CSF and blood. CSF stroke volume (SV), blood SV, and arterial and venous pulsatility indexes (PIs) were assessed at intra- and extracranial levels in both samples. Correlations between ventricular and spinal CSF flow, and between blood and CSF flow during aging were also assessed. Results There was a significant decrease in arterial cerebral blood flow and intracranial venous cerebral blood flow with aging. We also found a significant increase of intracranial blood SV, spinal CSF SV and arterial/venous pulsatility indexes with aging. In regard to intracranial compartment impact, arterial and venous PIs decreased significantly at intracranial level in elderly volunteers, while young adults exhibited decrease in venous PI only. Intracranial venous PI was paradoxically lower than extracranial venous PI, regardless of age. In both sample groups, spinal CSF SV and aqueductal CSF SV were positively correlated, and so were extracranial blood and spinal CSF SVs. Conclusion The study demonstrates that aging changes blood flow but preserves blood and CSF interactions. We also showed that many parameters related to blood and CSF flows differ between young and elderly adults.
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Durand MJ, Beckert AK, Peterson CY, Ludwig KA, Ridolfi TJ, Lauer KK, Freed JK. You Are Only as Frail as Your Arteries: Prehabilitation of Elderly Surgical Patients. CURRENT ANESTHESIOLOGY REPORTS 2019. [DOI: 10.1007/s40140-019-00357-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Abstract
Purpose of Review
To discuss the concept of prehabilitation for the elderly frail surgical patient as well as strategies to improve preoperative functional capacity and vascular function to decrease postoperative complications.
Recent Findings
Frailty is associated with poor surgical outcomes yet there is no consensus on how frailty should be measured or mitigated in the preoperative period. Prehabilitation, or improving functional capacity prior to surgery typically through exercise, has been shown to be an effective strategy to decrease preoperative frailty and improves surgical outcomes. Use of remote ischemic preconditioning (RIPC) may serve as an alternative to exercise in this fragile patient population.
Summary
Prehabilitation programs using strategies targeted at improving vascular function may decrease frailty in the preoperative period and improve surgical outcomes in the elderly population.
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66
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Birnefeld J, Wåhlin A, Eklund A, Malm J. Cerebral arterial pulsatility is associated with features of small vessel disease in patients with acute stroke and TIA: a 4D flow MRI study. J Neurol 2019; 267:721-730. [PMID: 31728712 PMCID: PMC7035303 DOI: 10.1007/s00415-019-09620-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 10/30/2019] [Accepted: 11/02/2019] [Indexed: 11/16/2022]
Abstract
Cerebral small vessel disease (SVD) is a major cause of stroke and cognitive impairment. However, the underlying mechanisms behind SVD are still poorly understood. High cerebral arterial pulsatility has been suggested as a possible cause of SVD. In population studies, arterial pulsatility has been linked to white matter hyperintensities (WMH), cerebral atrophy, and cognitive impairment, all features of SVD. In stroke, pulsatility data are scarce and contradictory. The aim of this study was to investigate the relationship between arterial pulsatility and SVD in stroke patients. With a cross-sectional design, 89 patients with acute ischemic stroke or TIA were examined with MRI. A neuropsychological assessment was performed 1 year later. Using 4D flow MRI, pulsatile indices (PI) were calculated for the internal carotid artery (ICA) and middle cerebral artery (M1, M3). Flow volume pulsatility (FVP), a measure corresponding to the cyclic expansion of the arterial tree, was calculated for the same locations. These parameters were assessed for associations with WMH volume, brain volume and cognitive function. ICA-FVP was associated with WMH volume (β = 1.67, 95% CI: [0.1, 3.24], p = 0.037). M1-PI and M1-FVP were associated with decreasing cognitive function (β = − 4.4, 95% CI: [− 7.7, − 1.1], p = 0.009 and β = − 13.15, 95% CI: [− 24.26, − 2.04], p = 0.02 respectively). In summary, this supports an association between arterial pulsatility and SVD in stroke patients, and provides a potential target for further research and preventative treatment. FVP may become a useful biomarker for assessing pulsatile stress with PCMRI and 4D flow MRI.
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Affiliation(s)
- Johan Birnefeld
- Department of Pharmacology and Clinical Neuroscience, Umeå University, 90187, Umeå, Sweden.
| | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Centre for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Centre for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden
| | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, 90187, Umeå, Sweden
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Holmgren M, Wåhlin A, Dunås T, Malm J, Eklund A. Assessment of Cerebral Blood Flow Pulsatility and Cerebral Arterial Compliance With 4D Flow MRI. J Magn Reson Imaging 2019; 51:1516-1525. [PMID: 31713964 PMCID: PMC7216927 DOI: 10.1002/jmri.26978] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/08/2019] [Accepted: 10/08/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Four-dimensional flow magnetic resonance imaging (4D flow MRI) enables efficient investigation of cerebral blood flow pulsatility in the cerebral arteries. This is important for exploring hemodynamic mechanisms behind vascular diseases associated with arterial pulsations. PURPOSE To investigate the feasibility of pulsatility assessments with 4D flow MRI, its agreement with reference two-dimensional phase-contrast MRI (2D PC-MRI) measurements, and to demonstrate how 4D flow MRI can be used to assess cerebral arterial compliance and cerebrovascular resistance in major cerebral arteries. STUDY TYPE Prospective. SUBJECTS Thirty-five subjects (20 women, 79 ± 5 years, range 70-91 years). FIELD STRENGTH/SEQUENCE 4D flow MRI (PC-VIPR) and 2D PC-MRI acquired with a 3T scanner. ASSESSMENT Time-resolved flow was assessed in nine cerebral arteries. From the pulsatile flow waveform in each artery, amplitude (ΔQ), volume load (ΔV), and pulsatility index (PI) were calculated. To reduce high-frequency noise in the 4D flow MRI data, the flow waveforms were low-pass filtered. From the total cerebral blood flow, total PI (PItot ), total volume load (ΔVtot ), cerebral arterial compliance (C), and cerebrovascular resistance (R) were calculated. STATISTICAL TESTS Two-tailed paired t-test, intraclass correlation (ICC). RESULTS There was no difference in ΔQ between 4D flow MRI and the reference (0.00 ± 0.022 ml/s, mean ± SEM, P = 0.97, ICC = 0.95, n = 310) with a cutoff frequency of 1.9 Hz and 15 cut plane long arterial segments. For ΔV, the difference was -0.006 ± 0.003 ml (mean ± SEM, P = 0.07, ICC = 0.93, n = 310) without filtering. Total R was 11.4 ± 2.41 mmHg/(ml/s) (mean ± SD) and C was 0.021 ± 0.009 ml/mmHg (mean ± SD). ΔVtot was 1.21 ± 0.29 ml (mean ± SD) with an ICC of 0.82 compared with the reference. PItot was 1.08 ± 0.21 (mean ± SD). DATA CONCLUSION We successfully assessed 4D flow MRI cerebral arterial pulsatility, cerebral arterial compliance, and cerebrovascular resistance. Averaging of multiple cut planes and low-pass filtering was necessary to assess accurate peak-to-peak features in the flow rate waveforms. LEVEL OF EVIDENCE 2 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1516-1525.
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Affiliation(s)
| | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Tora Dunås
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden.,Center for Demographic and Aging Research, Umeå University, Umeå, Sweden
| | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
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Chronic Standing Desk Use and Arterial Stiffness. J Phys Act Health 2019; 16:1022-1028. [DOI: 10.1123/jpah.2018-0668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 05/03/2019] [Accepted: 06/27/2019] [Indexed: 11/18/2022]
Abstract
Background: Sedentary activity and sitting for at least 10 hours per day can increase the risk for cardiovascular disease by more than 60%. Use of standing desks may decrease sedentary time and improve cardiovascular health. Acute standing lowers pulse wave velocity (PWV), but chronic effects remain unknown. The purpose of this study was to determine the effect of chronic standing desk use on arterial stiffness versus seated controls. Methods: A total of 48 adults participated in this study. Twenty-four participants qualified as seated desk users (age 41 [10] y, body mass index 25 [4] kg/m2) and 24 as standing desk users (age 45 [12] y, body mass index 25 [5] kg/m2). Arterial stiffness was assessed as PWV within the aorta, arm, and leg. Results: Carotid–femoral PWV (cfPWV) was not different between seated (6.6 [1.3] m/s) and standing (6.9 [1.3] m/s) groups (P = .47). Similarly, there were no differences in arm or leg PWV between groups (P = .13 and P = .66, respectively). A secondary analysis of traditional factors of age and aerobic fitness revealed significant differences in cfPWV in seated and standing desk participants. Age also significantly influenced cfPWV across conditions. Conclusions: Standing for >50% of a workday did not affect PWV. Consistent with previous research, fitness and age are important modulators of arterial stiffness.
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Chen SP, Chou KH, Fuh JL, Huang YH, Huang CC, Lirng JF, Wang YF, Lin CP, Wang SJ. Dynamic Changes in White Matter Hyperintensities in Reversible Cerebral Vasoconstriction Syndrome. JAMA Neurol 2019; 75:1106-1113. [PMID: 29868878 DOI: 10.1001/jamaneurol.2018.1321] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Importance White matter hyperintense lesions (WMHs) are highly prevalent in patients with reversible cerebral vasoconstriction syndrome (RCVS); however, their characteristics and underlying pathophysiology are unclear. Objective To investigate the spatiotemporal distribution and pathomechanisms of WMHs in patients with RCVS. Design, Setting, and Participants We prospectively recruited patients with RCVS over a 3-year period from January 2010 through December 2012 from the headache center or emergency department of Taipei Veterans General Hospital, Taipei, Taiwan, a 2947-bed national medical center. In total, 85 patients with RCVS were approached, of whom 4 declined to participate, 5 declined follow-up scans, 6 were lost to follow-up, and 5 had suboptimal images. Patients received serial isotropic 3-dimension fluid-attenuated inversion recovery sequence imaging (1-mm slice thickness) with a 3-T magnetic resonance imaging machine as well as transcranial and extracranial color-coded sonography on registration and during follow-ups (at 1 and 2 months, with variations adapting to clinical condition). Data were analyzed from January 2015 to May 2017. Main Outcomes and Measures The fluid-attenuated inversion recovery lesion segmentation toolbox was used to segment WMHs automatically. The WMHs were classified as periventricular or deep and were segmented into 13 anatomical locations. The neuroimaging scientists who executed the program were blinded to clinical information. Vascular parameters, including the Lindegaard index (vasoconstriction severity), pulsatility index, and resistance index of the internal carotid artery, were independently collected for comparison. Results Sixty-five patients with RCVS completed the study and underwent a total of 162 magnetic resonance imaging examinations. Of the 65 included patients, 58 (89%) were women, and the mean (SD) age was 50.1 (8.9) years. The total mean (SD) WMH load peaked at 3.2 (4.4) cm3 in the third week postonset and fell to 0.8 (0.6) cm3 in the fourth week. White matter hyperintensities were predominantly frontal and periventricular. White matter hyperintensity load correlated strongly with Lindegaard index during the second week of the disease course (r = 0.908; P < .001) and also correlated with the pulsatility index and resistance index of the internal carotid artery. Conclusions and Relevance White matter hyperintensities in patients with RCVS have a dynamic temporal evolution that parallels disease severity. The finding of partially reversible WMHs deserves attention and should be known by clinicians taking care of patients with RCVS. White matter hyperintensities in RCVS may be attributed, at least partially, to regional hypoperfusion and impaired dampening capacity to central pulsatile flow.
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Affiliation(s)
- Shih-Pin Chen
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.,Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,Division of Translational Research, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.,Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Kun-Hsien Chou
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan.,Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan
| | - Jong-Ling Fuh
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Hua Huang
- Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan
| | - Chu-Chung Huang
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan
| | - Jiing-Feng Lirng
- Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.,Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yen-Feng Wang
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Ching-Po Lin
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan.,Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.,Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.,Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Shuu-Jiun Wang
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
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70
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Bink DI, Lozano-Vidal N, Boon RA. Long Non-Coding RNA in Vascular Disease and Aging. Noncoding RNA 2019; 5:ncrna5010026. [PMID: 30893946 PMCID: PMC6468806 DOI: 10.3390/ncrna5010026] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/13/2019] [Accepted: 03/14/2019] [Indexed: 12/16/2022] Open
Abstract
Cardiovascular diseases are the most prominent cause of death in Western society, especially in the elderly. With the increasing life expectancy, the number of patients with cardiovascular diseases will rise in the near future, leading to an increased healthcare burden. There is a need for new therapies to treat this growing number of patients. The discovery of long non-coding RNAs has led to a novel group of molecules that could be considered for their potential as therapeutic targets. This review presents an overview of long non-coding RNAs that are regulated in vascular disease and aging and which might therefore give insight into new pathways that could be targeted to diagnose, prevent, and/or treat vascular diseases.
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Affiliation(s)
- Diewertje I Bink
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, VU University, 1081HV Amsterdam, The Netherlands.
| | - Noelia Lozano-Vidal
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, VU University, 1081HV Amsterdam, The Netherlands.
| | - Reinier A Boon
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, VU University, 1081HV Amsterdam, The Netherlands.
- Institute of Cardiovascular Regeneration, Goethe University, 60596 Frankfurt am Main, Germany.
- German Center for Cardiovascular Research (DZHK), Partner Site Rhein-Main, 13347 Berlin, Germany.
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71
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Barnes JN, Harvey RE, Eisenmann NA, Miller KB, Johnson MC, Kruse SM, Lahr BD, Joyner MJ, Miller VM. Cerebrovascular reactivity after cessation of menopausal hormone treatment. Climacteric 2019; 22:182-189. [PMID: 30661405 DOI: 10.1080/13697137.2018.1538340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Women who are currently using menopausal hormone therapy (MHT) have higher cerebrovascular reactivity when compared with postmenopausal women who are not taking MHT; however, the effect of cessation of MHT on cerebrovascular reactivity is not known. Given that MHT can have structural and activational effects on vascular function, this study was performed to characterize cerebrovascular reactivity following cessation of MHT in women at low risk for cerebrovascular disease. METHODS Cerebrovascular reactivity was measured in a subset of women from the Kronos Early Estrogen Prevention Study (KEEPS) 3 years after cessation of the study drug (oral conjugated equine estrogen, transdermal 17β-estradiol, or placebo [PLA]). RESULTS Age, body mass index, and blood pressure were comparable among groups. At rest, the middle cerebral artery velocity (MCAv), cerebrovascular conductance index, mean arterial pressure, and cerebral pulsatility index did not differ among groups. Slope-based summary measures of cerebrovascular reactivity did not differ significantly among groups. However, utilizing repeated-measures modeling, there was a significant upward shift in MCAv responses (p = 0.029) in the combined MHT group compared with the PLA group. CONCLUSION MHT has a marginal sustained effect on cerebrovascular reactivity when measured 3 years after cessation of hormone treatment.
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Affiliation(s)
- J N Barnes
- a Department of Kinesiology , University of Wisconsin-Madison , Madison , WI , USA.,b Department of Anesthesiology , Mayo Clinic , Rochester , MN , USA
| | - R E Harvey
- b Department of Anesthesiology , Mayo Clinic , Rochester , MN , USA.,c College of Medicine and Science , Mayo Clinic , Rochester , MN , USA
| | - N A Eisenmann
- a Department of Kinesiology , University of Wisconsin-Madison , Madison , WI , USA
| | - K B Miller
- a Department of Kinesiology , University of Wisconsin-Madison , Madison , WI , USA
| | - M C Johnson
- b Department of Anesthesiology , Mayo Clinic , Rochester , MN , USA
| | - S M Kruse
- b Department of Anesthesiology , Mayo Clinic , Rochester , MN , USA
| | - B D Lahr
- d Department of Health Science Research , Mayo Clinic , Rochester , MN , USA
| | - M J Joyner
- b Department of Anesthesiology , Mayo Clinic , Rochester , MN , USA
| | - V M Miller
- e Department of Physiology and Biomedical Engineering , Mayo Clinic , Rochester , MN , USA.,f Department of Surgery , Mayo Clinic , Rochester , MN , USA
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72
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Dunås T, Holmgren M, Wåhlin A, Malm J, Eklund A. Accuracy of blood flow assessment in cerebral arteries with 4D flow MRI: Evaluation with three segmentation methods. J Magn Reson Imaging 2019; 50:511-518. [PMID: 30637846 PMCID: PMC6767555 DOI: 10.1002/jmri.26641] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 12/20/2018] [Accepted: 12/20/2018] [Indexed: 12/03/2022] Open
Abstract
Background Accelerated 4D flow MRI allows for high‐resolution velocity measurements with whole‐brain coverage. Such scans are increasingly used to calculate flow rates of individual arteries in the vascular tree, but detailed information about the accuracy and precision in relation to different postprocessing options is lacking. Purpose To evaluate and optimize three proposed segmentation methods and determine the accuracy of in vivo 4D flow MRI blood flow rate assessments in major cerebral arteries, with high‐resolution 2D PCMRI as a reference. Study Type Prospective. Subjects Thirty‐five subjects (20 women, 79 ± 5 years, range 70–91 years). Field Strength/Sequence 4D flow MRI with PC‐VIPR and 2D PCMRI acquired with a 3 T scanner. Assessment We compared blood flow rates measured with 4D flow MRI, to the reference, in nine main cerebral arteries. Lumen segmentation in the 4D flow MRI was performed with k‐means clustering using four different input datasets, and with two types of thresholding methods. The threshold was defined as a percentage of the maximum intensity value in the complex difference image. Local and global thresholding approaches were used, with evaluated thresholds from 6–26%. Statistical Tests Paired t‐test, F‐test, linear correlation (P < 0.05 was considered significant) along with intraclass correlation (ICC). Results With the thresholding methods, the lowest average flow difference was obtained for 20% local (0.02 ± 15.0 ml/min, ICC = 0.97, n = 310) or 10% global (0.08 ± 17.3 ml/min, ICC = 0.97, n = 310) thresholding with a significant lower standard deviation for local (F‐test, P = 0.01). For all clustering methods, we found a large systematic underestimation of flow compared with 2D PCMRI (16.1–22.3 ml/min). Data Conclusion A locally adapted threshold value gives a more stable result compared with a globally fixed threshold. 4D flow with the proposed segmentation method has the potential to become a useful reliable clinical tool for assessment of blood flow in the major cerebral arteries. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:511–518.
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Affiliation(s)
- Tora Dunås
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | | | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
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73
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An Observational Study of Cerebral Blood Flow Velocity Evaluation in the Prone Position During Posterior Lumbar Surgery. Anesth Analg 2018; 129:487-492. [PMID: 30418236 DOI: 10.1213/ane.0000000000003892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Prone positioning (PP) is necessary for surgical access during posterior spine procedure. However, physiological changes occur in the PP. Typical findings are a decrease in arterial blood pressure and in cardiac output that could potentially lead to an alteration in cerebral perfusion. Therefore, we decided to study cerebral blood flow velocity (CBFV) with transcranial Doppler ultrasonography to evaluate the effect of the PP on cerebral hemodynamics. METHODS Twenty-two patients undergoing spine surgery in the PP were studied. General anesthesia was induced using 250 μg of fentanyl, 2 mg/kg of propofol, and 0.1 mg/kg of vecuronium, and was maintained with 0.25%-0.5% isoflurane, 50% nitrous oxide in oxygen, continuous infusion of 100 μg/kg/min of propofol, 1.5 μg/kg/h of fentanyl, and 0.15 mg/kg/h of ketamine. Continuous invasive arterial blood pressure, heart rate, electrocardiogram, and end-tidal carbon dioxide were monitored. CBFV with transcranial Doppler in the middle cerebral artery was first measured with the patients under general anesthesia in the supine position. Patients were then placed in the PP and remained in this position throughout surgery. CBFV, end-tidal carbon dioxide, heart rate, and blood pressure were measured continuously for 75 minutes after initiation of PP. This coincided with surgical exposure and minimal blood loss. Data were analyzed every 15 minutes for statistical significant change over time. RESULTS Mean arterial blood pressure decreased 15 minutes after the installation of the PP and onward, but this decrease was not statistically significant. CBFVsyst (the maximal CBFV during the systolic phase of a cardiac cycle) and CBFVmean (the time averaged value of the maximal velocity envelope over 1 cardiac cycle) did not vary at any time points. CBFVdiast (the CBFV just before the acceleration phase [systole] of the next waveform) was lower at T3 (30 minutes after PP) compared to T1 (value derived averaging the first measure in the PP with the ones at 5 and 10 minutes) (P = .01), and the pulsatility index was higher at T5 (60 minutes after PP) compared to T0 (baseline, patient supine under general anesthesia) (P = .04). Data were analyzed at specific time points (T0 and T1). This value was derived by computing an average of the CBFV values collected at the first measure in the PP and at 5 and 10 minutes thereafter: T2, 15 minutes after PP; T3, 30 minutes after PP; T4, 45 minutes after PP; T5, 60 minutes after PP; and T6, 75 minutes after PP. CONCLUSIONS Our data on CBFV during PP for spine surgery demonstrate preservation of cerebral perfusion during stable systemic hemodynamic conditions. The present results do not allow us to determine whether the PP would be similarly tolerated with increasing length of surgery, variations in systemic hemodynamics, and in different patient populations.
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Abstract
Advancing age promotes cardiovascular disease (CVD), the leading cause of death in the United States and many developed nations. Two major age-related arterial phenotypes, large elastic artery stiffening and endothelial dysfunction, are independent predictors of future CVD diagnosis and likely are responsible for the development of CVD in older adults. Not limited to traditional CVD, these age-related changes in the vasculature also contribute to other age-related diseases that influence mammalian health span and potential life span. This review explores mechanisms that influence age-related large elastic artery stiffening and endothelial dysfunction at the tissue level via inflammation and oxidative stress and at the cellular level via Klotho and energy-sensing pathways (AMPK [AMP-activated protein kinase], SIRT [sirtuins], and mTOR [mammalian target of rapamycin]). We also discuss how long-term calorie restriction-a health span- and life span-extending intervention-can prevent many of these age-related vascular phenotypes through the prevention of deleterious alterations in these mechanisms. Lastly, we discuss emerging novel mechanisms of vascular aging, including senescence and genomic instability within cells of the vasculature. As the population of older adults steadily expands, elucidating the cellular and molecular mechanisms of vascular dysfunction with age is critical to better direct appropriate and measured strategies that use pharmacological and lifestyle interventions to reduce risk of CVD within this population.
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Affiliation(s)
- Anthony J. Donato
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, Utah
- Veterans Affairs Medical Center-Salt Lake City, Geriatrics Research Education and Clinical Center, Salt Lake City, Utah
| | - Daniel R. Machin
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, Utah
- Veterans Affairs Medical Center-Salt Lake City, Geriatrics Research Education and Clinical Center, Salt Lake City, Utah
| | - Lisa A. Lesniewski
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, Utah
- Veterans Affairs Medical Center-Salt Lake City, Geriatrics Research Education and Clinical Center, Salt Lake City, Utah
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75
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Engel DC, Adib SD, Schuhmann MU, Brendle C. Paradigm-shift: radiological changes in the asymptomatic iNPH-patient to be: an observational study. Fluids Barriers CNS 2018; 15:5. [PMID: 29422104 PMCID: PMC5806389 DOI: 10.1186/s12987-018-0090-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/19/2018] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Many radiological signs are known for the diagnosis of idiopathic normal pressure hydrocephalus (iNPH). However, there is little information about these signs in the pre-symptomatic phase. For pathophysiological investigative purposes we conducted a descriptive image analysis study on pre-symptomatic patients. METHODS Patients that had contact with either the neurological or neurosurgical department of the university hospital Tuebingen from 2010 through 2016 with magnetic resonance images > 3 years before onset of symptoms, were included. The date of onset and severity of symptoms, date of first imaging and birth date were recorded. Evan's index (EI), width of the third ventricle (3VW), tight high convexity (THC), Sylvian fissure, extent of white matter hyperintensities and aqueductal flow were assessed in images before and around symptom onset. RESULTS Ten patients were included. In all ten patients the first symptom was gait disturbance. Nine of ten pre-symptomatic images showed classic signs for iNPH. EI showed a significant increase between the pre-symptomatic and symptomatic phase. 3VW showed a trend for increase without significance. THC changed back and forth over time within some patients. CONCLUSIONS In accordance with the scarce literature available, radiological changes are present at least 3 years before onset of iNPH-symptoms. EI seems to be a robust measure for pre-symptomatic radiological changes. Extrapolating the data, the development of iNPH typical changes might be an insidious process and the development of THC might be a variable and non-linear process. Further studies with larger sample sizes are necessary to put these findings into the pathophysiological perspective for the development of iNPH.
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Affiliation(s)
- D. C. Engel
- Department of Neurosurgery, University Hospital of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany
| | - S. D. Adib
- Department of Neurosurgery, University Hospital of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany
| | - M. U. Schuhmann
- Department of Neurosurgery, University Hospital of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany
| | - C. Brendle
- Department of Neuroradiology, University Hospital of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany
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76
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Chnafa C, Brina O, Pereira VM, Steinman DA. Better Than Nothing: A Rational Approach for Minimizing the Impact of Outflow Strategy on Cerebrovascular Simulations. AJNR Am J Neuroradiol 2018; 39:337-343. [PMID: 29269407 DOI: 10.3174/ajnr.a5484] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/13/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Computational fluid dynamics simulations of neurovascular diseases are impacted by various modeling assumptions and uncertainties, including outlet boundary conditions. Many studies of intracranial aneurysms, for example, assume zero pressure at all outlets, often the default ("do-nothing") strategy, with no physiological basis. Others divide outflow according to the outlet diameters cubed, nominally based on the more physiological Murray's law but still susceptible to subjective choices about the segmented model extent. Here we demonstrate the limitations and impact of these outflow strategies, against a novel "splitting" method introduced here. MATERIALS AND METHODS With our method, the segmented lumen is split into its constituent bifurcations, where flow divisions are estimated locally using a power law. Together these provide the global outflow rate boundary conditions. The impact of outflow strategy on flow rates was tested for 70 cases of MCA aneurysm with 0D simulations. The impact on hemodynamic indices used for rupture status assessment was tested for 10 cases with 3D simulations. RESULTS Differences in flow rates among the various strategies were up to 70%, with a non-negligible impact on average and oscillatory wall shear stresses in some cases. Murray-law and splitting methods gave flow rates closest to physiological values reported in the literature; however, only the splitting method was insensitive to arbitrary truncation of the model extent. CONCLUSIONS Cerebrovascular simulations can depend strongly on the outflow strategy. The default zero-pressure method should be avoided in favor of Murray-law or splitting methods, the latter being released as an open-source tool to encourage the standardization of outflow strategies.
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Affiliation(s)
- C Chnafa
- From the Biomedical Simulation Laboratory (C.C., D.A.S.), Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada
| | - O Brina
- Joint Division of Medical Imaging (O.B., V.M.P.), Department of Medical Imaging and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, and University of Toronto, Toronto, Ontario, Canada
| | - V M Pereira
- Joint Division of Medical Imaging (O.B., V.M.P.), Department of Medical Imaging and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, and University of Toronto, Toronto, Ontario, Canada
| | - D A Steinman
- From the Biomedical Simulation Laboratory (C.C., D.A.S.), Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada
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77
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Zwanenburg JJM. Increased Rather than Decreased Small Vessel Pulsatility in Patients with Progressing Cerebral White Matter Hyperintensities. Radiology 2018; 286:363-364. [DOI: 10.1148/radiol.2017172090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jaco J. M. Zwanenburg
- Department of Radiology, E.01.132, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands
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78
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Heffernan KS, Augustine JA, Lefferts WK, Spartano NL, Hughes WE, Jorgensen RS, Gump BB. Arterial stiffness and cerebral hemodynamic pulsatility during cognitive engagement in younger and older adults. Exp Gerontol 2018; 101:54-62. [DOI: 10.1016/j.exger.2017.11.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/07/2017] [Indexed: 11/17/2022]
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Schnerr RS, Jansen JFA, Uludag K, Hofman PAM, Wildberger JE, van Oostenbrugge RJ, Backes WH. Pulsatility of Lenticulostriate Arteries Assessed by 7 Tesla Flow MRI-Measurement, Reproducibility, and Applicability to Aging Effect. Front Physiol 2017; 8:961. [PMID: 29225580 PMCID: PMC5705621 DOI: 10.3389/fphys.2017.00961] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/10/2017] [Indexed: 01/26/2023] Open
Abstract
Characterization of flow properties in cerebral arteries with 1.5 and 3 Tesla MRI is usually limited to large cerebral arteries and difficult to evaluate in the small perforating arteries due to insufficient spatial resolution. In this study, we assessed the feasibility to measure blood flow waveforms in the small lenticulostriate arteries with 7 Tesla velocity-sensitive MRI. The middle cerebral artery was included as reference. Imaging was performed in five young and five old healthy volunteers. Flow was calculated by integrating time-varying velocity values over the vascular cross-section. MRI acquisitions were performed twice in each subject to determine reproducibility. From the flow waveforms, the pulsatility index and damping factor were deduced. Reproducibility values, in terms of the intraclass correlation coefficients, were found to be good to excellent. Measured pulsatility index of the lenticulostriate arteries significantly increased and damping factor significantly decreased with age. In conclusion, we demonstrate that blood flow through the lenticostriate arteries can be precisely measured using 7 Tesla MRI and reveal effects of arterial stiffness due to aging. These findings hold promise to provide relevant insights into the pathologies involving perforating cerebral arteries.
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Affiliation(s)
- Roald S Schnerr
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands
| | - Jacobus F A Jansen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands.,Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Kamil Uludag
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Paul A M Hofman
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands.,Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Joachim E Wildberger
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands.,Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands.,Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands
| | - Robert J van Oostenbrugge
- Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands.,Department of Neurology, Maastricht University Medical Center, Maastricht, Netherlands
| | - Walter H Backes
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands.,Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands.,Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands
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80
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Akintola AA, van Opstal AM, Westendorp RG, Postmus I, van der Grond J, van Heemst D. Effect of intranasally administered insulin on cerebral blood flow and perfusion; a randomized experiment in young and older adults. Aging (Albany NY) 2017; 9:790-802. [PMID: 28291957 PMCID: PMC5391232 DOI: 10.18632/aging.101192] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/26/2017] [Indexed: 12/19/2022]
Abstract
Insulin, a vasoactive modulator regulating peripheral and cerebral blood flow, has been consistently linked to aging and longevity. In this proof of principle study, using a randomized, double-blinded, placebo-controlled crossover design, we explored the effects of intranasally administered insulin (40IU) on cerebral blood flow (CBF) and perfusion in older (60-69 years, n=11) and younger (20-26 years, n=8) adults. Changes in CBF through the major cerebropetal arteries were assessed via phase contrast MR-angiography, and regional cortical tissue perfusion via pseudo-continuous arterial spin labelling. Total flow through the major cerebropetal arteries was unchanged in both young and old. In the older participants, intranasal insulin compared to placebo increased perfusion through the occipital gray matter (65.2±11.0 mL/100g/min vs 61.2±10.1 mL/100g/min, P=0.001), and in the thalamus (68.28±6.75 mL/100g/min versus 63.31±6.84 mL/100g/min, P=0.003). Thus, intranasal insulin improved tissue perfusion of the occipital cortical brain region and the thalamus in older adults.
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Affiliation(s)
- Abimbola A Akintola
- Department of Internal Medicine, section Gerontology and Geriatrics, Leiden University Medical Centre, Leiden, the Netherlands
| | - Anna M van Opstal
- Department of Radiology, Leiden University Medical Centre, Leiden, the Netherlands
| | - Rudi G Westendorp
- Department of Internal Medicine, section Gerontology and Geriatrics, Leiden University Medical Centre, Leiden, the Netherlands.,Department of Public Health and Center for Healthy Aging, University of Copenhagen, Denmark
| | - Iris Postmus
- Department of Internal Medicine, section Gerontology and Geriatrics, Leiden University Medical Centre, Leiden, the Netherlands
| | - Jeroen van der Grond
- Department of Radiology, Leiden University Medical Centre, Leiden, the Netherlands.,Netherlands Consortium for Healthy Ageing, Leiden, the Netherlands
| | - Diana van Heemst
- Department of Internal Medicine, section Gerontology and Geriatrics, Leiden University Medical Centre, Leiden, the Netherlands.,Netherlands Consortium for Healthy Ageing, Leiden, the Netherlands
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81
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de Roos A, van der Grond J, Mitchell G, Westenberg J. Magnetic Resonance Imaging of Cardiovascular Function and the Brain: Is Dementia a Cardiovascular-Driven Disease? Circulation 2017; 135:2178-2195. [PMID: 28559496 DOI: 10.1161/circulationaha.116.021978] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The proximal aorta acts as a coupling device between heart and brain perfusion, modulating the amount of pressure and flow pulsatility transmitted into the cerebral microcirculation. Stiffening of the proximal aorta is strongly associated with age and hypertension. The detrimental effects of aortic stiffening may result in brain damage as well as heart failure. The resulting cerebral small vessel disease and heart failure may contribute to early cognitive decline and (vascular) dementia. This pathophysiological sequence of events underscores the role of cardiovascular disease as a contributory mechanism in causing cognitive decline and dementia and potentially may provide a starting point for prevention and treatment. Magnetic resonance imaging is well suited to assess the function of the proximal aorta and the left ventricle (eg, aortic arch pulse wave velocity and distensibility) as well as the various early and late manifestations of cerebral small vessel disease (eg, microbleeds and white matter hyperintensities in strategically important regions of the brain). Specialized magnetic resonance imaging techniques are explored for diagnosing preclinical changes in white matter integrity or brain microvascular pulsatility.
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Affiliation(s)
- Albert de Roos
- From Leiden University Medical Center, Department of Radiology, The Netherlands (A.d.R., J.v.d.G., J.W.); and Cardiovascular Engineering, Inc, Norwood, MA (G.M.).
| | - Jeroen van der Grond
- From Leiden University Medical Center, Department of Radiology, The Netherlands (A.d.R., J.v.d.G., J.W.); and Cardiovascular Engineering, Inc, Norwood, MA (G.M.)
| | - Gary Mitchell
- From Leiden University Medical Center, Department of Radiology, The Netherlands (A.d.R., J.v.d.G., J.W.); and Cardiovascular Engineering, Inc, Norwood, MA (G.M.)
| | - Jos Westenberg
- From Leiden University Medical Center, Department of Radiology, The Netherlands (A.d.R., J.v.d.G., J.W.); and Cardiovascular Engineering, Inc, Norwood, MA (G.M.)
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82
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Rivera-Rivera LA, Schubert T, Turski P, Johnson KM, Berman SE, Rowley HA, Carlsson CM, Johnson SC, Wieben O. Changes in intracranial venous blood flow and pulsatility in Alzheimer's disease: A 4D flow MRI study. J Cereb Blood Flow Metab 2017; 37:2149-2158. [PMID: 27492950 PMCID: PMC5464708 DOI: 10.1177/0271678x16661340] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/16/2016] [Accepted: 06/23/2016] [Indexed: 01/09/2023]
Abstract
Cerebral blood flow, arterial pulsation, and vasomotion may be important indicators of cerebrovascular health in aging and diseases of aging such as Alzheimer's disease. Noninvasive markers that assess these characteristics may be helpful in the study of co-occurrence of these diseases and potential additive and interacting effects. In this study, 4D flow MRI was used to measure intra-cranial flow features with cardiac-gated phase contrast MRI in cranial arteries and veins. Mean blood flow and pulsatility index as well as the transit time of the peak flow from the middle cerebral artery to the superior sagittal sinus were measured in a total of 104 subjects comprising of four groups: (a) subjects with Alzheimer's disease, (b) age-matched controls, (c) subjects with mild cognitive impairment, and (d) a group of late middle-aged with parental history of sporadic Alzheimer's disease. The Alzheimer's disease group exhibited: a significant decrease in mean blood flow in the superior sagittal sinus, transverse sinus, middle cerebral artery, and internal carotid arteries; a significant decrease of the peak and end diastolic blood flow in the middle cerebral artery and superior sagittal sinus; a faster transmission of peak flow from the middle cerebral artery to the superior sagittal sinus and increased pulsatility index along the carotid siphon.
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Affiliation(s)
- Leonardo A Rivera-Rivera
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Tilman Schubert
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Clinic of Radiology and Nuclear Medicine, Basel University Hospital, Basel, Switzerland
| | - Patrick Turski
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Kevin M Johnson
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Sara E Berman
- Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Howard A Rowley
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Cynthia M Carlsson
- Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Memorial VA Hospital, Madison, USA
- Wisconsin Alzheimer’s Institute, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Sterling C Johnson
- Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Memorial VA Hospital, Madison, USA
- Wisconsin Alzheimer’s Institute, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Oliver Wieben
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, USA
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83
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Qvarlander S, Ambarki K, Wåhlin A, Jacobsson J, Birgander R, Malm J, Eklund A. Cerebrospinal fluid and blood flow patterns in idiopathic normal pressure hydrocephalus. Acta Neurol Scand 2017; 135:576-584. [PMID: 27388230 DOI: 10.1111/ane.12636] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Increased aqueduct cerebrospinal fluid (CSF) flow pulsatility and, recently, a reversed CSF flow in the aqueduct have been suggested as hallmarks of idiopathic normal pressure hydrocephalus (INPH). However, these findings have not been adequately confirmed. Our objective was to investigate the flow of blood and CSF in INPH, as compared to healthy elderly, in order to clarify which flow parameters are related to the INPH pathophysiology. MATERIALS AND METHODS Sixteen INPH patients (73 years) and 35 healthy subjects (72 years) underwent phase-contrast magnetic resonance imaging (MRI). Measurements included aqueduct and cervical CSF flow, total arterial inflow (tCBF; i.e. carotid + vertebral arteries), and internal jugular vein flow. Flow pulsatility, net flow, and flow delays were compared (multiple linear regression, correcting for sex and age). RESULTS Aqueduct stroke volume was higher in INPH than healthy (148±95 vs 90±50 mL, P<.05). Net aqueduct CSF flow was similar in magnitude and direction. The cervical CSF stroke volume was lower (P<.05). The internal carotid artery net flow was lower in INPH (P<.05), although tCBF was not. No differences were found in internal jugular vein flow or flow delays. CONCLUSIONS The typical flow of blood and CSF in INPH was mainly characterized by increased CSF pulsatility in the aqueduct and reduced cervical CSF pulsatility. The direction of mean net aqueduct CSF flow was from the third to the fourth ventricle. Our findings may reflect the altered distribution of intracranial CSF volume in INPH, although the causality of these relationships is unclear.
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Affiliation(s)
- S. Qvarlander
- Department of Radiation Sciences; Umeå University; Umeå Sweden
- Centre for Biomedical Engineering and Physics; Umeå University; Umeå Sweden
| | - K. Ambarki
- Department of Radiation Sciences; Umeå University; Umeå Sweden
- Centre for Biomedical Engineering and Physics; Umeå University; Umeå Sweden
| | - A. Wåhlin
- Department of Radiation Sciences; Umeå University; Umeå Sweden
- Umeå Centre for Functional Brain Imaging; Umeå University; Umeå Sweden
| | - J. Jacobsson
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - R. Birgander
- Department of Radiation Sciences; Umeå University; Umeå Sweden
| | - J. Malm
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - A. Eklund
- Department of Radiation Sciences; Umeå University; Umeå Sweden
- Centre for Biomedical Engineering and Physics; Umeå University; Umeå Sweden
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Lee WJ, Jung KH, Ryu YJ, Lee KJ, Kim JM, Lee ST, Chu K, Kim M, Lee SK, Roh JK. Progression of Cerebral White Matter Hyperintensities and the Associated Sonographic Index. Radiology 2017; 284:824-833. [PMID: 28394756 DOI: 10.1148/radiol.2017162064] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Purpose To evaluate the relationship between penetrating arterial pulsation and the progression of white matter hyperintensities (WMHs) by using the sonographic resistance index (RI) along the M1 segment of the middle cerebral artery (MCA). Materials and Methods The study design was approved by the institutional review board of Seoul National University Hospital. The study included 450 individuals who had undergone initial transcranial Doppler (TCD) sonography and magnetic resonance imaging, with follow-up imaging performed within 34-45 months, and who had no stenosis of 30% or more in the internal carotid artery or MCA or a history of stroke other than an old lacunar infarction. MRIR was defined as distal RI divided by proximal RI, where the distance between proximal MI and distal M1 was approximately 20 mm based on TCD evaluation. WMH progression was quantitatively evaluated by subtracting WMH volume at baseline from WMH volume at follow-up. Results At baseline, mean MRIR was 0.974 ± 0.045 (standard deviation), and mean WMH volume was 9.66 mL ± 14.54. After a mean of 38.3 months ± 3.4, the WMH volume change was 4.06 mL ± 7.35. WMH volume change was linearly associated with MRIR (r = 0.328, P < .001), along with the baseline WMH volume (r = 0.433, P < .001) and mean MCA pulsatility index (r = 0.275, P = .037). MRIR values greater than or equal to 1.000 were associated with a greater increase in WMH volume (P < .001). Conclusion MRIR might reflect the pulsation of penetrating arteries and is independently associated with WMH progression. © RSNA, 2017 Online supplemental material is available for this article.
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Affiliation(s)
- Woo-Jin Lee
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
| | - Keun-Hwa Jung
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
| | - Young Jin Ryu
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
| | - Keon-Joo Lee
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
| | - Jeong-Min Kim
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
| | - Soon-Tae Lee
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
| | - Kon Chu
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
| | - Manho Kim
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
| | - Sang Kun Lee
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
| | - Jae-Kyu Roh
- From the Departments of Neurology (W.J.L., K.H.J., K.J.L., S.T.L., K.C., M.K., S.K.L., J.K.R.) and Radiology (Y.J.R.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, South Korea; Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea (K.H.J., S.T.L., K.C., M.K., S.K.L.); Department of Neurology, Chung-Ang University Hospital, Seoul, South Korea (J.M.K.); and Department of Neurology, the Armed Forces Capital Hospital, Sungnam, South Korea (J.K.R.)
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Bouillot P, Delattre BMA, Brina O, Ouared R, Farhat M, Chnafa C, Steinman DA, Lovblad KO, Pereira VM, Vargas MI. 3D phase contrast MRI: Partial volume correction for robust blood flow quantification in small intracranial vessels. Magn Reson Med 2017; 79:129-140. [PMID: 28244132 DOI: 10.1002/mrm.26637] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/19/2017] [Accepted: 01/19/2017] [Indexed: 11/11/2022]
Abstract
PURPOSE Recent advances in 3D-PCMRI (phase contrast MRI) sequences allow for measuring the complex hemodynamics in cerebral arteries. However, the small size of these vessels vs spatial resolution can lead to non-negligible partial volume artifacts, which must be taken into account when computing blood flow rates. For this purpose, we combined the velocity information provided by 3D-PCMRI with vessel geometry measured with 3DTOF (time of flight MRI) or 3DRA (3D rotational angiography) to correct the partial volume effects in flow rate assessments. METHODS The proposed methodology was first tested in vitro on cylindrical and patient specific vessels subject to fully controlled pulsatile flows. Both 2D- and 3D-PCMRI measurements using various spatial resolutions ranging from 20 to 1.3 voxels per vessel diameter were analyzed and compared with flowmeter baseline. Second, 3DTOF, 2D- and 3D-PCMRI measurements were performed in vivo on 35 patients harboring internal carotid artery (ICA) aneurysms indicated for endovascular treatments requiring 3DRA imaging. RESULTS The in vitro 2D- and 3D-PCMRI mean flow rates assessed with partial volume correction showed very low sensitivity to the acquisition resolution above ≈2 voxels per vessel diameter while uncorrected flow rates deviated critically when decreasing the spatial resolution. 3D-PCMRI flow rates measured in vivo in ICA agreed very well with 2D-PCMRI data and a good flow conservation was observed at the C7 bifurcation. Globally, partial volume correction led to 10-15% lower flow rates than uncorrected values as those reported in most of the published studies on intracranial flows. CONCLUSION Partial volume correction may improve the accuracy of PCMRI flow rate measurements especially in small vessels such as intracranial arteries. Magn Reson Med 79:129-140, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Pierre Bouillot
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bénédicte M A Delattre
- Division of Radiology, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
| | - Olivier Brina
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Rafik Ouared
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Mohamed Farhat
- Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Christophe Chnafa
- Biomedical Simulation Laboratory, Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Canada
| | - David A Steinman
- Biomedical Simulation Laboratory, Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Canada
| | - Karl-Olof Lovblad
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Vitor M Pereira
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Canada.,Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Maria I Vargas
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland
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