1
|
Correia de Verdier M, Berglund J, Wikström J. Effect of MRI acquisition parameters on accuracy and precision of phase-contrast measurements in a small-lumen vessel phantom. Eur Radiol Exp 2024; 8:45. [PMID: 38472565 DOI: 10.1186/s41747-024-00435-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/12/2024] [Indexed: 03/14/2024] Open
Abstract
BACKGROUND Phase-contrast magnetic resonance imaging (PC-MRI) quantifies blood flow and velocity noninvasively. Challenges arise in neurovascular disorders due to small vessels. We evaluated the impact of voxel size, number of signal averages (NSA), and velocity encoding (VENC) on PC-MRI measurement accuracy and precision in a small-lumen vessel phantom. METHODS We constructed an in vitro model with a constant flow rate using a 2.2-mm inner diameter plastic tube. A reservoir with a weight scale and timer was used as standard reference. Gradient-echo T1 weighted PC-MRI sequence was performed on a 3-T scanner with varying voxel size (2.5, 5.0, 7.5 mm3), NSA (1, 2, 3), and VENC (200, 300, 400 cm/s). We repeated measurements nine times per setting, calculating mean flow rate, maximum velocity, and least detectable difference (LDD). RESULTS PC-MRI flow measurements were higher than standard reference values (mean ranging from 7.3 to 9.5 mL/s compared with 6.6 mL/s). Decreased voxel size improved accuracy, reducing flow rate measurements from 9.5 to 7.3 mL/s. The LDD for flow rate and velocity varied between 1 and 5%. The LDD for flow rate decreased with increased voxel size and NSA (p = 0.033 and 0.042). The LDD for velocity decreased with increased voxel size (p < 10-16). No change was observed when VENC varied. CONCLUSIONS PC-MRI overestimated flow. However, it has high precision in a small-vessel phantom with constant flow rate. Improved accuracy was obtained with increasing spatial resolution (smaller voxels). Improved precision was obtained with increasing signal-to-noise ratio (larger voxels and/or higher NSA). RELEVANCE STATEMENT Phase-contrast MRI is clinically used in large vessels. To further investigate the possibility of using phase-contrast MRI for smaller intracranial vessels in neurovascular disorders, we need to understand how acquisition parameters affect phase-contrast MRI-measured flow rate and velocity in small vessels. KEY POINTS • PC-MRI measures flow and velocity in a small lumen phantom with high precision but overestimates flow rate. • The precision of PC-MRI measurements matches the precision of standard reference for flow rate measurements. • Optimizing PC-MRI settings can enhance accuracy and precision in flow rate and velocity measurements.
Collapse
Affiliation(s)
- Maria Correia de Verdier
- Department of Surgical Sciences, Section of Neuroradiology, Uppsala University, Uppsala, Sweden.
| | - Johan Berglund
- Department of Surgical Sciences, Section of Molecular Imaging and Medical Physics, Uppsala University, Uppsala, Sweden
| | - Johan Wikström
- Department of Surgical Sciences, Section of Neuroradiology, Uppsala University, Uppsala, Sweden
| |
Collapse
|
2
|
Owashi KP, Capel C, Balédent O. Cerebral arterial flow dynamics during systole and diastole phases in young and older healthy adults. Fluids Barriers CNS 2023; 20:65. [PMID: 37705096 PMCID: PMC10500860 DOI: 10.1186/s12987-023-00467-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 09/05/2023] [Indexed: 09/15/2023] Open
Abstract
BACKGROUND Since arterial flow is the leading actor in neuro-fluids flow dynamics, it might be interesting to assess whether it is meaningful to study the arterial flow waveform in more detail and whether this provides new important information. Few studies have focused on determining the influence of heart rate variation over time on the arterial flow curve. Therefore, this study aimed to evaluate cerebral arterial flow waveforms at extracranial and intracranial compartments in young and elderly healthy adults, also considering systole and diastole phases. METHODS Cine phase-contrast magnetic resonance imaging (CINE-PC MRI) was performed on twenty-eight healthy young volunteers (HYV) and twenty healthy elderly volunteers (HEV) to measure arterial blood flows at the extracranial and intracranial planes. A semi-automated protocol using MATLAB scripts was implemented to identify the main representative points in the arterial flow waveforms. Representative arterial profiles were estimated for each group. Moreover, the effects of age and sex on flow times, amplitude-related parameters, and parameters related to systole and diastole phases were evaluated at the extracranial and intracranial compartments. Student's t-test or Wilcoxon's test (depending on the normality of the distribution) was used to detect significant differences. RESULTS In HYVs, significant differences were observed between extracranial and intracranial levels in parameters related to the AP1 amplitude. Besides the detected differences in pulsatility index (extracranial: 0.92 ± 0.20 vs. 1.28 ± 0.33; intracranial: 0.79 ± 0.15 vs. 1.14 ± 0.18, p < .001) and average flow (715 ± 136 vs. 607 ± 125 ml/min, p = .008) between HYV and HEV, differences in the amplitude value of the arterial flow profile feature points were also noted. Contrary to systole duration (HYV: 360 ± 29 ms; HEV: 364 ± 47 ms), diastole duration presented higher inter-individual variability in both populations (HYV: 472 ± 145 ms; HEV: 456 ± 106 ms). Our results also showed that, with age, it is mainly the diastolic phase that changes. Although no significant differences in duration were observed between the two populations, the mean flow value in the diastolic phase was significantly lower in HEV (extracranial: 628 ± 128 vs. 457 ± 111 ml/min; intracranial: 599 ± 121 vs. 473 ± 100 ml/min, p < .001). No significant differences were observed in the arterial flow parameters evaluated between females and males in either HYV or HEV. CONCLUSION Our study provides a novel contribution on the influence of the cardiac cycle phases on cerebral arterial flow. The main contribution in this study concerns the identification of age-related alterations in cerebral blood flow, which occur mainly during the diastolic phase. Specifically, we observed that mean flow significantly decreases with age during diastole, whereas mean flow during systole is consistent.
Collapse
Affiliation(s)
| | - Cyrille Capel
- CHIMERE UR 7516, Jules Verne University of Picardy, Amiens, France
- Neurosurgery Department, Amiens Picardy University Medical Center, Amiens, France
| | - Olivier Balédent
- CHIMERE UR 7516, Jules Verne University of Picardy, Amiens, France
- Medical Image Processing Department, Amiens Picardy University Medical Center, Amiens, France
| |
Collapse
|
3
|
Domogo AA, Reinstrup P, Ottesen JT. Mechanistic-mathematical modeling of intracranial pressure (ICP) profiles over a single heart cycle. The fundament of the ICP curve form. J Theor Biol 2023; 564:111451. [PMID: 36907263 DOI: 10.1016/j.jtbi.2023.111451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/31/2022] [Accepted: 02/28/2023] [Indexed: 03/13/2023]
Abstract
The intracranial pressure (ICP) curve with its different peaks has been comprehensively studied, but the exact physiological mechanisms behind its morphology has not been revealed. If the pathophysiology behind deviations from the normal ICP curve form could be identified, it could be vital information to diagnose and treat each single patient. A mathematical model of the hydrodynamics in the intracranial cavity over single heart cycles was developed. A Windkessel model approach was generalized but the unsteady Bernoulli equation was utilized for blood flow and CSF flow. This is a modification of earlier models using the extended and simplified classical Windkessel analogies to a model that is based on mechanisms rooted in the laws of physics. The improved model was calibrated with patient data for cerebral arterial inflow, venous outflow, cerebrospinal fluid (CSF), and ICP over one heart cycle from 10 neuro-intensive care unit patients. A priori model parameter values were obtained by considering patient data and values taken from earlier studies. These values were used as an initial guess for an iterated constrained-ODE (ordinary differential equation) optimization problem with cerebral arterial inflow data as input into the system of ODEs. The optimization routine found patient-specific model parameter values that produced model ICP curves that showed excellent agreement with clinical measurements while model venous and CSF flow were within a physiologically acceptable range. The improved model and the automated optimization routine gave better model calibration results compared to previous studies. Moreover, patient-specific values of physiologically important parameters like intracranial compliance, arterial and venous elastance, and venous outflow resistance were determined. The model was used to simulate intracranial hydrodynamics and to explain the underlying mechanisms of the ICP curve morphology. Sensitivity analysis showed that the order of the three main peaks of the ICP curve was affected by a decrease in arterial elastance, a large increase in resistance to arteriovenous flow, an increase in venous elastance, or a decrease in resistance to CSF flow in the foramen magnum; and the frequency of oscillations were notably affected by intracranial elastance. In particular, certain pathological peak patterns were caused by these changes in physiological parameters. To the best of our knowledge, there are no other mechanism-based models associating the pathological peak patterns to variation of the physiological parameters.
Collapse
Affiliation(s)
- Andrei A Domogo
- Department of Mathematics and Computer Science, University of the Philippines Baguio, Baguio City 2600, Philippines; IMFUFA, Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark.
| | - Peter Reinstrup
- Intensive and Perioperative Care, Skåne University Hospital, Lund, Sweden.
| | - Johnny T Ottesen
- Center for Mathematical Modeling - Human Health and Disease (COMMAND), Roskilde University, 4000 Roskilde, Denmark; IMFUFA, Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark.
| |
Collapse
|
4
|
Vandenbulcke S, De Pauw T, Dewaele F, Degroote J, Segers P. Computational fluid dynamics model to predict the dynamical behavior of the cerebrospinal fluid through implementation of physiological boundary conditions. Front Bioeng Biotechnol 2022; 10:1040517. [PMID: 36483773 PMCID: PMC9722737 DOI: 10.3389/fbioe.2022.1040517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 11/11/2022] [Indexed: 10/22/2023] Open
Abstract
Cerebrospinal fluid (CSF) dynamics play an important role in maintaining a stable central nervous system environment and are influenced by different physiological processes. Multiple studies have investigated these processes but the impact of each of them on CSF flow is not well understood. A deeper insight into the CSF dynamics and the processes impacting them is crucial to better understand neurological disorders such as hydrocephalus, Chiari malformation, and intracranial hypertension. This study presents a 3D computational fluid dynamics (CFD) model which incorporates physiological processes as boundary conditions. CSF production and pulsatile arterial and venous volume changes are implemented as inlet boundary conditions. At the outlets, 2-element windkessel models are imposed to simulate CSF compliance and absorption. The total compliance is first tuned using a 0D model to obtain physiological pressure pulsations. Then, simulation results are compared with in vivo flow measurements in the spinal subarachnoid space (SAS) and cerebral aqueduct, and intracranial pressure values reported in the literature. Finally, the impact of the distribution of and total compliance on CSF pressures and velocities is evaluated. Without respiration effects, compliance of 0.17 ml/mmHg yielded pressure pulsations with an amplitude of 5 mmHg and an average value within the physiological range of 7-15 mmHg. Also, model flow rates were found to be in good agreement with reported values. However, when adding respiration effects, similar pressure amplitudes required an increase of compliance value to 0.51 ml/mmHg, which is within the range of 0.4-1.2 ml/mmHg measured in vivo. Moreover, altering the distribution of compliance over the four different outlets impacted the local flow, including the flow through the foramen magnum. The contribution of compliance to each outlet was directly proportional to the outflow at that outlet. Meanwhile, the value of total compliance impacted intracranial pressure. In conclusion, a computational model of the CSF has been developed that can simulate CSF pressures and velocities by incorporating boundary conditions based on physiological processes. By tuning these boundary conditions, we were able to obtain CSF pressures and flows within the physiological range.
Collapse
Affiliation(s)
- Sarah Vandenbulcke
- Institute of Biomedical Engineering and Technology (IBiTech-bioMMeda), Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Tim De Pauw
- Department of Neurosurgery, Ghent University Hospital, Ghent, Belgium
| | - Frank Dewaele
- Department of Neurosurgery, Ghent University Hospital, Ghent, Belgium
| | - Joris Degroote
- Department of Electromechanical Systems and Metal Engineering, Ghent University, Ghent, Belgium
| | - Patrick Segers
- Institute of Biomedical Engineering and Technology (IBiTech-bioMMeda), Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| |
Collapse
|
5
|
Capel C, Padovani P, Launois PH, Metanbou S, Balédent O, Peltier J. Insights on the Hydrodynamics of Chiari Malformation. J Clin Med 2022; 11:jcm11185343. [PMID: 36142990 PMCID: PMC9501326 DOI: 10.3390/jcm11185343] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/30/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
Background: We propose that the appearance of a ptosis of the cerebellar tonsils and syringomyelia is linked to its own hemohydrodynamic mechanisms. We aimed to quantify cerebrospinal fluid (CSF) and cerebral blood flow to highlight how neurofluid is affected by Chiari malformations type 1(CMI) and its surgery. Methods: We retrospectively included 21 adult patients with CMI who underwent pre- and postoperative phase contrast MRI (PCMRI) during the period from 2001 to 2017. We analyzed intraventricular CSF, subarachnoid spaces CSF, blood, and tonsils pulsatilities. Results: In preoperative period, jugular venous drainage seems to be less preponderant in patients with syringomyelia than other patients (venous correction factor: 1.49 ± 0.4 vs. 1.19 ± 0.1, p = 0.05). After surgery, tonsils pulsatility decreased significantly (323 ± 175 μL/cardiac cycle (CC) vs. 194 ± 130 μL/CC, p = 0.008) and subarachnoid CSF pulsatility at the foramen magnum increased significantly (201 ± 124 μL/CC vs. 363 ± 231 μL/CC, p = 0.02). After surgery, we found a decrease in venous flow amplitude (5578 ± 2469 mm3/s vs. 4576 ± 2084 mm3/s, p = 0.008) and venous correction factor (1.98 ± 0.3 vs. 1.20 ± 0.3 mm3/s, p = 0.004). Conclusions: Phase-contrast MRI could be a useful additional tool for postoperative evaluation and follow-up, and is complementary to morphological imaging.
Collapse
Affiliation(s)
- Cyrille Capel
- Department of Neurosurgery, Hospital University Center of Amiens-Picardie, 80054 Amiens, France
- Chimère UR 7516, Jules Verne University, 80000 Amiens, France
- Correspondence:
| | - Pauline Padovani
- Department of Neurosurgery, Hospital University Center of Amiens-Picardie, 80054 Amiens, France
| | - Pierre-Henri Launois
- Department of Neurosurgery, Hospital University Center of Amiens-Picardie, 80054 Amiens, France
| | - Serge Metanbou
- Radiology Department, Hospital University Center of Amiens-Picardie, 80054 Amiens, France
| | - Olivier Balédent
- Chimère UR 7516, Jules Verne University, 80000 Amiens, France
- Radiology Department, Hospital University Center of Amiens-Picardie, 80054 Amiens, France
- Image Processing Department, Hospital University Center of Amiens-Picardie, 80054 Amiens, France
| | - Johann Peltier
- Department of Neurosurgery, Hospital University Center of Amiens-Picardie, 80054 Amiens, France
- Chimère UR 7516, Jules Verne University, 80000 Amiens, France
| |
Collapse
|
6
|
Yildiz S, Grinstead J, Hildebrand A, Oshinski J, Rooney WD, Lim MM, Oken B. Immediate impact of yogic breathing on pulsatile cerebrospinal fluid dynamics. Sci Rep 2022; 12:10894. [PMID: 35764793 PMCID: PMC9240010 DOI: 10.1038/s41598-022-15034-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 06/16/2022] [Indexed: 01/10/2023] Open
Abstract
Cerebrospinal fluid (CSF), a clear fluid bathing the central nervous system (CNS), undergoes pulsatile movements. Together with interstitial fluid, CSF plays a critical role for the removal of waste products from the brain, and maintenance of the CNS health. As such, understanding the mechanisms driving CSF movement is of high scientific and clinical impact. Since pulsatile CSF dynamics is sensitive and synchronous to respiratory movements, we are interested in identifying potential integrative therapies such as yogic breathing to regulate CSF dynamics, which has not been reported before. Here, we investigated the pre-intervention baseline data from our ongoing randomized controlled trial, and examined the impact of four yogic breathing patterns: (i) slow, (ii) deep abdominal, (iii) deep diaphragmatic, and (iv) deep chest breathing with the last three together forming a yogic breathing called three-part breath. We utilized our previously established non-invasive real-time phase contrast magnetic resonance imaging approach using a 3T MRI instrument, computed and tested differences in single voxel CSF velocities (instantaneous, respiratory, cardiac 1st and 2nd harmonics) at the level of foramen magnum during spontaneous versus yogic breathing. In examinations of 18 healthy participants (eight females, ten males; mean age 34.9 ± 14 (SD) years; age range: 18-61 years), we observed immediate increase in cranially-directed velocities of instantaneous-CSF 16-28% and respiratory-CSF 60-118% during four breathing patterns compared to spontaneous breathing, with the greatest changes during deep abdominal breathing (28%, p = 0.0008, and 118%, p = 0.0001, respectively). Cardiac pulsation was the primary source of pulsatile CSF motion except during deep abdominal breathing, when there was a comparable contribution of respiratory and cardiac 1st harmonic power [0.59 ± 0.78], suggesting respiration can be the primary regulator of CSF depending on the individual differences in breathing techniques. Further work is needed to investigate the impact of sustained training yogic breathing on pulsatile CSF dynamics for CNS health.
Collapse
Affiliation(s)
- Selda Yildiz
- Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA.
| | - John Grinstead
- Siemens Medical Solutions USA, Inc, Portland, OR, 97239, USA
| | - Andrea Hildebrand
- Biostatistics and Design Program, Oregon Health & Science University, Portland, OR, 97239, USA
| | - John Oshinski
- Radiology & Imaging Sciences and Biomedical Engineering, Emory School of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - William D Rooney
- Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, 97239, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Miranda M Lim
- Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
- VA Portland Health Care System, Portland, OR, 97239, USA
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Barry Oken
- Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
| |
Collapse
|
7
|
AYADI ASMA, SAHTOUT WASSILA, BALEDENT OLIVIER. COMPARISON BETWEEN TWO NONINVASIVE METHODS USED TO ESTIMATE BIOMECHANICAL PROPERTIES OF THE INTERNAL CAROTID ARTERY. J MECH MED BIOL 2022. [DOI: 10.1142/s0219519422500269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Background: Many cardiovascular diseases modified the arterial wall stiffness. Objectives: This work focuses on the quantification of the elastic biomechanical properties of the internal carotid (ICA) wall by applying the cepstral analysis on healthy volunteers aged from 22 to 86 years old. The purpose of this study is to compare two methods of measurement of arterial compliance ([Formula: see text], arterial distensibility ([Formula: see text], arterial elastance (Eh), and Young’s modulus ([Formula: see text]. Material and methods: First, arterial compliance and arterial distensibility were measured in function of wave speed ([Formula: see text], which is measured in our previous works by using two methods. Second, elastance Eh was estimated through the ratio between diastolic radius ([Formula: see text] and [Formula: see text]. Finally, [Formula: see text] was estimated from a statistical study from the literature on h due to the difficulty of measuring wall thickness ([Formula: see text]. Results: The Student test demonstrated that there is a very significant difference between young and old subjects in terms of elastance, compliance, and Young’s modulus ([Formula: see text]). These findings are in agreement with the reference values reported in the literature. They are very satisfying for distinguishing a pathological change in parietal elasticity. Conclusion: The in vivo application of these methods presents their potential for clinical measurement of arterial stiffness.
Collapse
Affiliation(s)
- ASMA AYADI
- Laboratory of Biophysics and Medical Technology, Higher Institute of Biotechnology of Sfax, University of Sfax, Tunisia
| | - WASSILA SAHTOUT
- Laboratory of Biophysics and Medical Technology, Higher Institute of Biotechnology of Sfax, University of Sfax, Tunisia
| | - OLIVIER BALEDENT
- Department of Imaging and Biophysics, University of Picardie Jules Verne, CHU Amiens 80054, France
| |
Collapse
|
8
|
Intracranial pulse pressure waveform analysis using the higher harmonics centroid. Acta Neurochir (Wien) 2021; 163:3249-3258. [PMID: 34387744 PMCID: PMC8599247 DOI: 10.1007/s00701-021-04958-1] [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: 05/24/2021] [Accepted: 07/25/2021] [Indexed: 11/30/2022]
Abstract
Background The pulse waveform of intracranial pressure (ICP) is its distinctive feature almost always present in the clinical recordings. In most cases, it changes proportionally to rising ICP, and observation of these changes may be clinically useful. We introduce the higher harmonics centroid (HHC) which can be defined as the center of mass of harmonics of the ICP pulse waveform from the 2nd to 10th, where mass corresponds to amplitudes of these harmonics. We investigate the changes in HHC during ICP monitoring, including isolated episodes of ICP plateau waves. Material and methods Recordings from 325 patients treated between 2002 and 2010 were reviewed. Twenty-six patients with ICP plateau waves were identified. In the first step, the correlation between HHC and ICP was examined for the entire monitoring period. In the second step, the above relation was calculated separately for periods of elevated ICP during plateau wave and the baseline. Results For the values averaged over the whole monitoring period, ICP (22.3 ± 6.9 mm Hg) correlates significantly (R = 0.45, p = 0.022) with HHC (3.64 ± 0.46). During the ICP plateau waves (ICP increased from 20.9 ± 6.0 to 53.7 ± 9.7 mm Hg, p < 10−16), we found a significant decrease in HHC (from 3.65 ± 0.48 to 3.21 ± 0.33, p = 10−5). Conclusions The good correlation between HHC and ICP supports the clinical application of pressure waveform analysis in addition to the recording of ICP number only. Mean ICP may be distorted by a zero drift, but HHC remains immune to this error. Further research is required to test whether a decline in HHC with elevated ICP can be an early warning sign of intracranial hypertension, whether individual breakpoints of correlation between ICP and its centroid are of clinical importance.
Collapse
|
9
|
Ophthalmic Artery and Superior Ophthalmic Vein Blood Flow Dynamics in Glaucoma Investigated by Phase Contrast Magnetic Resonance Imaging. J Glaucoma 2021; 30:65-70. [PMID: 32969916 DOI: 10.1097/ijg.0000000000001684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 09/03/2020] [Indexed: 11/26/2022]
Abstract
PRECIS Ophthalmic artery (OA) and superior ophthalmic vein (SOV) blood flow were quantified by phase contrast magnetic resonance imaging (PC MRI) and seemed lower in glaucoma. Venous flow dynamics was different in glaucoma patients with a significantly decreased pulsatility. INTRODUCTION Studies using color Doppler imaging and optical coherence tomography flowmetry strongly suggested that vascular changes are involved in the pathophysiology of glaucoma, but the venous outflow has been little studied beyond the episcleral veins. This study measured the OA and the SOV flow by PC MRI in glaucoma patients compared with controls. METHODS Eleven primary open-angle glaucoma patients, with a mean±SD visual field deficit of -2.3±2.7 dB and retinal nerve fiber layer thickness of 92±13 µ, and 10 controls of similar age, were examined by PC MRI. The mean, maximal and minimal flow over cardiac cycle were measured. The variation of flow (ΔQ) was calculated. RESULTS The OA mean±SD mean flow was 13.21±6.79 in patients and 15.09±7.62 mL/min in controls (P=0.35) and the OA maximal flow was 25.70±12.08 mL/min in patients, and 28.45±10.64 mL/min in controls (P=0.22). In the SOV the mean±SD mean flow was 6.46±5.50 mL/min in patients and 7.21±6.04 mL/min in controls (P=0.81) and the maximal flow was 9.06±6.67 in patients versus 11.96±9.29 mL/min in controls (P=0.47). The ΔQ in the SOV was significantly lower in patients (5.45±2.54 mL/min) than in controls (9.09±5.74 mL/min) (P=0.04). DISCUSSION Although no significant difference was found, the mean and maximal flow in the OA and SOV seemed lower in glaucoma patients than in controls. The SOV flow waveform might be affected in glaucoma, corroborating the hypothesis of an impairment of venous outflow in those patients.
Collapse
|
10
|
AYADI ASMA, SAHTOUT WASSILA, BALEDENT OLIVIER. COMPARATIVE STUDY FOR WAVE SPEED ESTIMATION AT A SINGLE AND TWO MEASUREMENT POINTS. J MECH MED BIOL 2021. [DOI: 10.1142/s0219519421500482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Local wave speed is a prognostic detector that allows the analysis of cardiovascular function. Objectives: This study compared wave speed ([Formula: see text] measurements at single-point and two-point techniques. Material and methods: [Formula: see text] were determined from the cepstral analysis of the blood flow velocities, which identified the arrivals times of reflected waves. The blood velocities waveforms were measured by using phase-contrast magnetic resonance (PCMR) for 20 subjects on young and old healthy subjects. Local wave speed was estimated through the arrivals time of reflections waves ([Formula: see text] and the distance separating the measurement site to reflection area ([Formula: see text] or the distance separating the two measurement sites. Results: Our obtained results were in total agreement with reference values reported in the literature. Moreover, the detected results show that there is a high correlation ([Formula: see text]) between the two methods. Conclusion: The analysis of the wave speed variations with advancing age is also achieved out through different regression models.
Collapse
Affiliation(s)
- ASMA AYADI
- Laboratory of Biophysics and Medical Technology, Higher Institute of Medical Technologies of Tunis, University of Tunis Manar, 9 Street Doctor Zouheïr Safi 1006, Tunisia
| | - WASSILA SAHTOUT
- Laboratory of Biophysics and Medical Technologies, Higher Institute of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - OLIVIER BALEDENT
- CHIMERE EA 7516 Research Team for Head & Neck, University of Picardie Jules Verne, CHU Amiens Sud, Bâtiment TEP 1er Étage, Unité de Traitement de l’image Médicale, Avenue René Laënnec, 80054 Amiens, France
| |
Collapse
|
11
|
Inflow Hemodynamics of Intracranial Aneurysms: A Comparison of Computational Fluid Dynamics and 4D Flow Magnetic Resonance Imaging. J Stroke Cerebrovasc Dis 2021; 30:105685. [PMID: 33662703 DOI: 10.1016/j.jstrokecerebrovasdis.2021.105685] [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: 01/03/2021] [Accepted: 02/13/2021] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Although the inflow hemodynamics of cerebral aneurysms are key factors in their rupture and recurrence after endovascular treatments, the most available method for inflow hemodynamics evaluation remains unestablished. We compared the efficacy of inflow hemodynamics evaluation using computational fluid dynamics (CFD) analysis and that using four-dimensional (4D) flow magnetic resonance imaging (MRI). METHODS In 23 unruptured cerebral aneurysms, the inflow hemodynamics was evaluated using both CFD and 4D flow MRI. The evaluated parameters included visually classified inflow jet patterns, the inflow rate ratio (the ratio of the inflow rate at the aneurysmal orifice to the flow rate in the proximal parent artery), and the velocity ratio (the ratio of the inflow velocity to the velocity in the proximal parent artery). The Shapiro-Wilk test was used to assess the normality of variable data, and logarithmic transformation was performed for variables with non-normal distributions. Data analysis was performed using Pearson correlation analyses and the chi-square test. RESULTS There was a significant correlation between inflow jet patterns evaluated by CFD and 4D flow MRI (p = 0.008). Moreover, there was a strong correlation between the inflow rate ratios evaluated by CFD and 4D flow MRI (r = 0.801; p <0.001). Furthermore, there was a moderate correlation between the velocity ratios measured by CFD and 4D flow MRI (r = 0.559; p = 0.008). CONCLUSION Inflow hemodynamics evaluated by CFD analysis and 4D flow MRI showed good correlations in inflow jet pattern, inflow rate ratio, and velocity ratio.
Collapse
|
12
|
Futami K, Misaki K, Uno T, Kamide T, Nakada M. Effect of Neck Size on the Inflow Magnitude Evaluated on 4D Flow MRI in Unruptured Internal Carotid Artery Aneurysms. J Stroke Cerebrovasc Dis 2020; 29:105116. [PMID: 32912568 DOI: 10.1016/j.jstrokecerebrovasdis.2020.105116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/27/2020] [Accepted: 06/29/2020] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND A neck size >4.0 mm is a risk factor for recanalization after coil embolization. The high inflow magnitude of pretreatment wide-neck aneurysms may be correlated to recanalization. We aimed to elucidate the effect of the neck size on the inflow magnitude evaluated on four-dimensional (4D) flow magnetic resonance imaging (MRI) in pretreatment unruptured internal carotid artery (ICA) aneurysms. METHODS Thirty-three untreated ICA aneurysms were subjected to 4D flow MRI to evaluate the inflow magnitude parameters including the maximum spatially-averaged inflow velocity (MSAIV), maximum inflow velocity, maximum inflow rate (MIR), and their ratios to each corresponding flow parameter in the parent artery. RESULTS The neck size was linearly correlated to all inflow parameters investigated in this study. A strong correlation was observed between the neck size and the following: MSAIV (r = .755, p < .0001), MIR (r = .715, p < .0001), MSAIV ratio (r = .724, p < .0001), and MIR ratio (r = .741, p < .0001). The predicted value of MIR ratio of an aneurysm with the neck size of 4.0 mm was 23.0% and 20.6%, based on the linear regression equation of all aneurysms and on that of aneurysms with the neck size >4.0 mm, respectively. CONCLUSIONS The neck size was linearly correlated with the inflow magnitude of unruptured ICA aneurysms. Inflow magnitude evaluation using 4D flow MRI may help to hemodynamically identify aneurysms with a high risk of recanalization after endovascular coil embolization.
Collapse
Affiliation(s)
- Kazuya Futami
- Department of Neurosurgery, Hokuriku Central Hospital, 123 Nodera, Oyabe, 932-8503 Toyama, Japan.
| | - Kouichi Misaki
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8641, Ishikawa, Japan
| | - Takehiro Uno
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8641, Ishikawa, Japan
| | - Tomoya Kamide
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8641, Ishikawa, Japan
| | - Mitsutoshi Nakada
- Department of Neurosurgery, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8641, Ishikawa, Japan
| |
Collapse
|
13
|
Ultrasonic Assessment of the Medial Temporal Lobe Tissue Displacements in Alzheimer’s Disease. Diagnostics (Basel) 2020; 10:diagnostics10070452. [PMID: 32635379 PMCID: PMC7399840 DOI: 10.3390/diagnostics10070452] [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: 06/17/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 12/31/2022] Open
Abstract
We aim to estimate brain tissue displacements in the medial temporal lobe (MTL) using backscattered ultrasound radiofrequency (US RF) signals, and to assess the diagnostic ability of brain tissue displacement parameters for the differentiation of patients with Alzheimer’s disease (AD) from healthy controls (HC). Standard neuropsychological evaluation and transcranial sonography (TCS) for endogenous brain tissue motion data collection are performed for 20 patients with AD and for 20 age- and sex-matched HC in a prospective manner. Essential modifications of our previous method in US waveform parametrization, raising the confidence of micrometer-range displacement signals in the presence of noise, are done. Four logistic regression models are constructed, and receiver operating characteristic (ROC) curve analyses are applied. All models have cut-offs from 61.0 to 68.5% and separate AD patients from HC with a sensitivity of 89.5% and a specificity of 100%. The area under a ROC curve of predicted probability in all models is excellent (from 95.2 to 95.7%). According to our models, AD patients can be differentiated from HC by a sharper morphology of some individual MTL spatial point displacements (i.e., by spreading the spectrum of displacements to the high-end frequencies with higher variability across spatial points within a region), by lower displacement amplitude differences between adjacent spatial points (i.e., lower strain), and by a higher interaction of these attributes.
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Adams AL, Viergever MA, Luijten PR, Zwanenburg JJM. Validating faster DENSE measurements of cardiac-induced brain tissue expansion as a potential tool for investigating cerebral microvascular pulsations. Neuroimage 2019; 208:116466. [PMID: 31843712 DOI: 10.1016/j.neuroimage.2019.116466] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 12/13/2019] [Indexed: 11/17/2022] Open
Abstract
Displacement Encoding with Stimulated Echoes (DENSE) has recently shown potential for measuring cardiac-induced cerebral volumetric strain in the human brain. As such, it may provide a powerful tool for investigating the cerebral small vessels. However, further development and validation are necessary. This study aims, first, to validate a retrospectively-gated implementation of the DENSE method for assessing brain tissue pulsations as a physiological marker, and second, to use the acquired measurements to explore intracranial volume dynamics. We acquired repeated measurements of cerebral volumetric strain in 8 healthy subjects, and internally validated these measurements by comparing them to spinal CSF stroke volumes obtained in the same scan session. Peak volumetric strain was found to be highly repeatable between scan sessions. First/second measured peak volumetric strains were: (6.4 ± 1.7)x10-4/(6.7 ± 1.6)x10-4 for whole brain, (9.5 ± 2.5)x10-4/(9.6 ± 2.4)x10-4 for grey matter, and (4.4 ± 1.7)x10-4/(4.1 ± 0.8)x10-4 for white matter. Grey matter showed significantly higher peak strain (p < 0.001) and earlier time-to-peak strain (p < 0.02) than white matter. An approximately linear relationship was found between CSF and brain tissue volume pulsations over the cardiac cycle (mean slope and R2 of 0.88 ± 0.23 and 0.89 ± 0.07, respectively). The close similarity between CSF and brain tissue volume pulsations implies limited contributions from large intracranial vessel pulsations, providing further evidence for venous compression as an additional mechanism for maintaining stable intracranial pressures over the cardiac cycle. Cerebral pulsatility showed consistent inter-subject peak values in healthy subjects, and was strongly correlated to CSF stroke volumes. These results strengthen the potential of brain tissue volumetric strain as a means for investigating the intracranial dynamics of the ageing brain in normal or diseased states.
Collapse
Affiliation(s)
- Ayodeji L Adams
- Department of Radiology, University Medical Center Utrecht, E 01.132, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands.
| | - Max A Viergever
- Image Sciences Institute, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands.
| | - Peter R Luijten
- Department of Radiology, University Medical Center Utrecht, E 01.132, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands.
| | - Jaco J M Zwanenburg
- Department of Radiology, University Medical Center Utrecht, E 01.132, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands.
| |
Collapse
|
16
|
Park J, Kim J, Chang Y, Youn SW, Lee HJ, Kang EJ, Lee KN, Suchánek V, Hyun S, Lee J. Analysis of the time-velocity curve in phase-contrast magnetic resonance imaging: a phantom study. Comput Assist Surg (Abingdon) 2019; 24:3-12. [PMID: 31385716 DOI: 10.1080/24699322.2019.1649066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The aim of this study was to analyze the characteristics of time-velocity curve acquired by phase-contrast magnetic resonance imaging (PC-MRI) using an in-vitro flow model as a reference for hemodynamic studies. The time- velocity curves of the PC-MRI were compared with Doppler ultrasonography (US) and also compared with those obtained in the electromagnetic flowmeter. The correlation between techniques was analyzed using an electromagnetic flowmeter as a reference standard; the maximum, minimum, and average velocities, full-width at half-maximum (FWHM), and ascending gradient (AG) were measured from time-velocity curves. The correlations between an electromagnetic flowmeter and the respective measurement technique for the PC-MRI and Doppler US were found to be high (mean R2 > 0.9, p < 0.05). These results indicate that these measurement techniques are useful for measuring blood flow information and reflect actual flow. The PC-MRI was the best fit for the minimum velocity and FWHM, and the maximum velocity and AG were the best fit for Doppler US. The PC-MRI showed lower maximum velocity value and higher minimum velocity value than Doppler US. Therefore, PC-MRI demonstrates more obtuse time-velocity curve than Doppler US. In addition, the time- velocity curve of PC-MRI could be calibrated by introducing formulae that can convert each measurement value to a reference standard value within a 10% error. The PC-MRI can be used to estimate the Doppler US using this formula.
Collapse
Affiliation(s)
- Jieun Park
- Department of Biomedical Engineering, Kyungpook National University , Daegu , Republic of Korea
| | - Junghun Kim
- Department of Biomedical Engineering, Kyungpook National University , Daegu , Republic of Korea
| | - Yongmin Chang
- Department of Radiology, Kyungpook National University & Hospital , Daegu , Republic of Korea
| | - Sung Won Youn
- Department of Radiology, Catholic University of Daegu Medical Center , Daegu , Republic of Korea
| | - Hui Joong Lee
- Department of Radiology, Kyungpook National University & Hospital , Daegu , Republic of Korea
| | - Eun-Ju Kang
- Department of Radiology, Dong-A University College of Medicine , Busan , Republic of Korea
| | - Ki-Nam Lee
- Department of Radiology, Dong-A University College of Medicine , Busan , Republic of Korea
| | - Vojtěch Suchánek
- Department of Radiology, Kyungpook National University & Hospital , Daegu , Republic of Korea
| | - Sinjae Hyun
- Department of Biomedical Engineering, Mercer University , Macon , GA , USA
| | - Jongmin Lee
- Department of Radiology, Kyungpook National University & Hospital , Daegu , Republic of Korea
| |
Collapse
|
17
|
Makki MI, O'Gorman RL, Buhler P, Baledent O, Kellenberger CJ, Sabandal C, Weiss M, Scheer I, Schmitz A. Total cerebrovascular blood flow and whole brain perfusion in children sedated using propofol with or without ketamine at induction: An investigation with 2D-Cine PC and ASL. J Magn Reson Imaging 2019; 50:1433-1440. [PMID: 30892782 DOI: 10.1002/jmri.26725] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Multiple sedation regimes may be used to facilitate pediatric MRI scans. These regimes might affect cerebral blood flow and hemodynamics to varying degrees, particularly in children who may be vulnerable to anesthetic side effects. PURPOSE To compare the effects of propofol monosedation solely (Pm group) vs. a combination of propofol and ketamine (KP group) on brain hemodynamics and perfusion. STUDY TYPE Prospective double-blind randomized trial. FIELD STRENGTH/SEQUENCES 1.5T and 3T. 2D-Cine phase contrast (2D-Cine PC) and pseudocontinuous arterial spin labeling (ASL). POPULATION Children aged from 3 months to 10 years referred for MRI with deep sedation were randomized into either the KP or the Pm group. Perfusion images were acquired with ASL followed by single-slice 2D-Cine PC acquired between the cervical vertebra C2 and C3. ASSESSMENT Average whole-brain perfusion (WBP ml.min-1 .100 ml-1 ) was extracted from the ASL perfusion maps and total cerebrovascular blood flow (CVF) was quantified by bilaterally summing the flow in the vertebral and the internal carotid arteries. The CVF values were converted to units of ml.min-1 .100 g-1 to calculate the tissue CVF100g (ml.min-1 .100 g-1 ). Images were assessed by a neuroradiologist and data from n = 81 (ASL) and n = 55 (PC) cases with no apparent pathology were entered into the analysis. STATISTICAL TESTS Multivariate analysis of covariance was performed to compare drug sedation effects on WBP, CVF, and CVF100g . RESULTS No significant difference in arterial flow was observed (P = 0.57), but the KP group showed significantly higher WBP than the Pm group, covarying for scanner and age (P = 0.003). A correlation analysis showed a significant positive correlation between mean WBP (ml.min-1 .100 g-1 ) and mean CVF100g . DATA CONCLUSION The KP group showed higher perfusion but no significant difference in vascular flow compared with the Pm group. WBP and CVF100g correlated significantly, but ASL appeared to have more susceptibility to perfusion differences arising from the different sedation regimes. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2019;50:1433-1440.
Collapse
Affiliation(s)
- Malek I Makki
- MRI Research Center, University Children's Hospital, Zurich, Switzerland.,Children's Research Center, University Children's Hospital, Zurich, Switzerland.,MRI Research GIE-FF, CHU Amiens Picardie, Amiens, France
| | - Ruth L O'Gorman
- MRI Research Center, University Children's Hospital, Zurich, Switzerland.,Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Philip Buhler
- Anesthesia, University Children Hospital, Zurich, Switzerland
| | | | - Christian J Kellenberger
- Children's Research Center, University Children's Hospital, Zurich, Switzerland.,Department of Diagnostic Radiology, University Children's Hospital, Zurich, Switzerland
| | - Carola Sabandal
- Children's Research Center, University Children's Hospital, Zurich, Switzerland.,Anesthesia, University Children Hospital, Zurich, Switzerland
| | - Markus Weiss
- Children's Research Center, University Children's Hospital, Zurich, Switzerland.,Anesthesia, University Children Hospital, Zurich, Switzerland
| | - Ianina Scheer
- Children's Research Center, University Children's Hospital, Zurich, Switzerland.,Department of Diagnostic Radiology, University Children's Hospital, Zurich, Switzerland
| | - Achim Schmitz
- Children's Research Center, University Children's Hospital, Zurich, Switzerland.,Anesthesia, University Children Hospital, Zurich, Switzerland
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
Fetal dynamic phase-contrast MR angiography using ultrasound gating and comparison with Doppler ultrasound measurements. Eur Radiol 2019; 29:4169-4176. [PMID: 30617486 DOI: 10.1007/s00330-018-5940-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/28/2018] [Accepted: 11/30/2018] [Indexed: 12/14/2022]
Abstract
OBJECTIVES To investigate the feasibility of fetal phase-contrast (PC)-MR angiography of the descending aorta (AoD) using an MR-compatible Doppler ultrasound sensor (DUS) for fetal cardiac gating and to compare velocimetry with Doppler ultrasound measurements. METHODS In this prospective study, 2D PC-MR angiography was performed in 12 human fetuses (mean gestational age 32.8 weeks) using an MR-compatible DUS for gating of the fetal heart at 1.5 T. Peak flow velocities in the fetal AoD were compared with Doppler ultrasound measurements performed on the same day. Reproducibility of PC-MR measurements was tested by repeated PC-MR in five fetuses. RESULTS Dynamic PC-MR angiography in the AoD was successfully performed in all fetuses using the DUS, with an average fetal heart rate of 140 bpm (range 129-163). Time-velocity curves revealed typical arterial blood flow patterns. PC-MR mean flow velocity and mean flux were 21.2 cm/s (range 8.6-36.8) and 8.4 ml/s (range 3.2-14.6), respectively. A positive association between PC-MR mean flux and stroke volume with gestational age was obtained (r = 0.66, p = 0.02 and r = 0.63, p = 0.03). PC-MR and Doppler ultrasound peak velocities revealed a highly significant correlation (r = 0.8, p < 0.002). Peak velocities were lower for PC-MR with 69.1 cm/s (range 39-125) compared with 96.7 cm/s (range 60-142) for Doppler ultrasound (p < 0.001). Reproducibility of PC-MR was high (p > 0.05). CONCLUSION The MR-compatible DUS for fetal cardiac gating allows for PC-MR angiography in the fetal AoD. Comparison with Doppler ultrasound revealed a highly significant correlation of peak velocities with underestimation of PC-MR velocities. This new technique for direct fetal cardiac gating indicates the potential of PC-MR angiography for assessing fetal hemodynamics. KEY POINTS • The developed MR-compatible Doppler ultrasound sensor allows direct fetal cardiac gating and can be used for prenatal dynamic cardiovascular MRI. • The MR-compatible Doppler ultrasound sensor was successfully applied to perform intrauterine phase-contrast MR angiography of the fetal aorta, which revealed a highly significant correlation with Doppler ultrasound measurements. • As fetal flow hemodynamics is an important parameter in the diagnosis and management of fetal pathologies, fetal phase-contrast MR angiography may offer an alternative imaging method in addition to Doppler ultrasound and develop as a second line tool in the evaluation of fetal flow hemodynamics.
Collapse
|
20
|
Quantification of blood flow in the superior ophthalmic vein using phase contrast magnetic resonance imaging. Exp Eye Res 2018; 176:40-45. [DOI: 10.1016/j.exer.2018.06.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/18/2018] [Accepted: 06/26/2018] [Indexed: 11/22/2022]
|
21
|
Brain pulsations enlightened. Acta Neurochir (Wien) 2018; 160:225-227. [PMID: 29273949 DOI: 10.1007/s00701-017-3436-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 12/12/2017] [Indexed: 10/18/2022]
|
22
|
Intracranial volumetric changes govern cerebrospinal fluid flow in the Aqueduct of Sylvius in healthy adults. Biomed Signal Process Control 2017. [DOI: 10.1016/j.bspc.2017.03.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
23
|
Zmudka JA, Sérot JM, Dao S, Sorel C, Macaret AS, Balédent O. Specific Effects of Anti-Hypertensive Treatment in an Older Patient with Dementia. Open Neurol J 2017; 11:15-19. [PMID: 28567135 PMCID: PMC5420187 DOI: 10.2174/1874205x01711010015] [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: 11/21/2016] [Revised: 02/15/2017] [Accepted: 02/17/2017] [Indexed: 11/22/2022] Open
Abstract
Dementia is one of the most common health problems in the world. Alzheimer’s disease (AD) is the most common form of dementia. The presence of vascular risk factors such as hypertension (HT) may increase the risk of AD [1,2]. The relation between blood pressure (BP) and dementia has been the subject of numerous epidemiological studies, midlife HT is a risk factor for dementia and AD [3-7] but the association between HT and risk of dementia is lower in the older population [8]. A fair modulation of an antihypertensive treatment, based on the cognitive status of the elderly, can avoid multiple complications. A case of an older for whom cognitive improvement and reduced risk of falls were noticed after mild blood pressure elevation is reported.
Collapse
Affiliation(s)
- Jadwiga Attier Zmudka
- Department of Gerontology, General Hospital Saint Quentin, BioFlowImage, University of Picardy Jules Verne, Amiens, France
| | - Jean Marie Sérot
- Department of Gerontology, General Hospital Saint Quentin, BioFlowImage, University of Picardy Jules Verne, Amiens, France
| | - Salif Dao
- Department of Radiology, General Hospital Saint Quentin, Saint Quentin, France
| | - Claire Sorel
- Department of Cardiology, General Hospital Saint Quentin, Saint Quentin, France
| | - Anne-Sophie Macaret
- Department of Neurology, General Hospital Saint Quentin, Saint Quentin, France
| | - Olivier Balédent
- BioFlowImage Image processing unit, University Hospital & University of Picardy Jules Verne, Amiens, France
| |
Collapse
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
Yildiz S, Thyagaraj S, Jin N, Zhong X, Heidari Pahlavian S, Martin BA, Loth F, Oshinski J, Sabra KG. Quantifying the influence of respiration and cardiac pulsations on cerebrospinal fluid dynamics using real-time phase-contrast MRI. J Magn Reson Imaging 2017; 46:431-439. [DOI: 10.1002/jmri.25591] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/28/2016] [Indexed: 02/05/2023] Open
Affiliation(s)
- Selda Yildiz
- Woodruff School of Mechanical Engineering; Georgia Institute of Technology; Atlanta Georgia USA
| | - Suraj Thyagaraj
- Department of Mechanical Engineering, Conquer Chiari Research Center; University of Akron; Akron Ohio USA
| | - Ning Jin
- MR R&D Collaborations; Siemens Healthcare; Columbus Ohio USA
| | - Xiaodong Zhong
- MR R&D Collaborations; Siemens Healthcare; Atlanta Georgia USA
- Department of Radiology; Emory University; Atlanta Georgia USA
| | - Soroush Heidari Pahlavian
- Department of Mechanical Engineering, Conquer Chiari Research Center; University of Akron; Akron Ohio USA
| | - Bryn A. Martin
- Department of Biological Engineering; University of Idaho; Moscow Idaho USA
| | - Francis Loth
- Department of Mechanical Engineering, Conquer Chiari Research Center; University of Akron; Akron Ohio USA
| | - John Oshinski
- Department of Radiology & Imaging Sciences and Biomedical Engineering; Emory University; Atlanta Georgia USA
| | - Karim G. Sabra
- Woodruff School of Mechanical Engineering; Georgia Institute of Technology; Atlanta Georgia USA
| |
Collapse
|
26
|
Zarrinkoob L, Ambarki K, Wåhlin A, Birgander R, Carlberg B, Eklund A, Malm J. Aging alters the dampening of pulsatile blood flow in cerebral arteries. J Cereb Blood Flow Metab 2016; 36:1519-27. [PMID: 26823470 PMCID: PMC5012521 DOI: 10.1177/0271678x16629486] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 12/28/2015] [Indexed: 01/13/2023]
Abstract
Excessive pulsatile flow caused by aortic stiffness is thought to be a contributing factor for several cerebrovascular diseases. The main purpose of this study was to describe the dampening of the pulsatile flow from the proximal to the distal cerebral arteries, the effect of aging and sex, and its correlation to aortic stiffness. Forty-five healthy elderly (mean age 71 years) and 49 healthy young (mean age 25 years) were included. Phase-contrast magnetic resonance imaging was used for measuring blood flow pulsatility index and dampening factor (proximal artery pulsatility index/distal artery pulsatility index) in 21 cerebral and extra-cerebral arteries. Aortic stiffness was measured as aortic pulse wave velocity. Cerebral arterial pulsatility index increased due to aging and this was more pronounced in distal segments of cerebral arteries. There was no difference in pulsatility index between women and men. Dampening of pulsatility index was observed in all cerebral arteries in both age groups but was significantly higher in young subjects than in elderly. Pulse wave velocity was not correlated with cerebral arterial pulsatility index. The increased pulsatile flow in elderly together with reduced dampening supports the pulse wave encephalopathy theory, since it implies that a higher pulsatile flow is reaching distal arterial segments in older subjects.
Collapse
Affiliation(s)
- Laleh Zarrinkoob
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Khalid Ambarki
- Department of Radiation Sciences, Umeå University, Umeå, Sweden Centre for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden
| | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | | | - Bo Carlberg
- Department of Public Health and Clinical Medicine, 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, Umeå, Sweden
| |
Collapse
|
27
|
Nucci CG, De Bonis P, Mangiola A, Santini P, Sciandrone M, Risi A, Anile C. Intracranial pressure wave morphological classification: automated analysis and clinical validation. Acta Neurochir (Wien) 2016; 158:581-8; discussion 588. [PMID: 26743919 DOI: 10.1007/s00701-015-2672-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 12/14/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND Recently, different software has been developed to automatically analyze multiple intracranial pressure (ICP) parameters, but the suggested methods are frequently complex and have no clinical correlation. The objective of this study was to assess the clinical value of a new morphological classification of the cerebrospinal fluid pulse pressure waveform (CSFPPW), comparing it to the elastance index (EI) and CSF-outflow resistance (Rout), and to test the efficacy of an automatic ICP analysis. METHODS An artificial neural network (ANN) was trained to classify 60 CSFPPWs in four different classes, according to their morphology, and its efficacy was compared to an expert examiner's classification. The morphology of CSFPPW, recorded in 60 patients at baseline, was compared to EI and Rout calculated at the end of an intraventricular infusion test to validate the utility of the proposed classification in patients' clinical evaluation. RESULTS The overall concordance in CSFPPW classification between the expert examiner and the ANN was 88.3 %. An elevation of EI was statistically related to morphological class' progression. All patients showing pathological baseline CSFPPW (class IV) revealed an alteration of CSF hydrodynamics at the end of their infusion test. CONCLUSIONS The proposed morphological classification estimates the global ICP wave and its ability to reflect or predict an alteration in CSF hydrodynamics. An ANN can be trained to efficiently recognize four different CSF wave morphologies. This classification seems helpful and accurate for diagnostic use.
Collapse
Affiliation(s)
- Carlotta Ginevra Nucci
- Institute of Neurosurgery, Catholic University School of Medicine, Largo A. Gemelli 8, Rome, Italy.
| | - Pasquale De Bonis
- Institute of Neurosurgery, Catholic University School of Medicine, Largo A. Gemelli 8, Rome, Italy
| | - Annunziato Mangiola
- Institute of Neurosurgery, Catholic University School of Medicine, Largo A. Gemelli 8, Rome, Italy
| | - Pietro Santini
- Institute of Neurosurgery, Catholic University School of Medicine, Largo A. Gemelli 8, Rome, Italy
| | - Marco Sciandrone
- Department of Information Engineering, University of Florence, Via di Santa Marta 3, Florence, Italy
| | - Arnaldo Risi
- Institute of System Analysis and Informatics, National Research Council, Viale Manzoni 30, Rome, Italy
| | - Carmelo Anile
- Institute of Neurosurgery, Catholic University School of Medicine, Largo A. Gemelli 8, Rome, Italy
| |
Collapse
|
28
|
Normal ranges and test-retest reproducibility of flow and velocity parameters in intracranial arteries measured with phase-contrast magnetic resonance imaging. Neuroradiology 2016; 58:521-31. [PMID: 26882908 DOI: 10.1007/s00234-016-1661-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/02/2016] [Indexed: 10/22/2022]
Abstract
INTRODUCTION The purpose of the present study was to investigate normal ranges and test-retest reproducibility of phase-contrast MRI (PC-MRI)-measured flow and velocity parameters in intracranial arteries. METHODS Highest flow (HF), lowest flow (LF), peak systolic velocity (PSV), and end diastolic velocity (EDV) were measured at two dates in the anterior (ACA), middle (MCA), and posterior (PCA) cerebral arteries of 30 healthy volunteers using two-dimensional PC-MRI at 3 T. Least detectable difference (LDD) was calculated. RESULTS In the left ACA, HF was (mean (range, LDD)) 126 ml/min (36-312, 59 %), LF 61 ml/min (0-156, 101 %), PSV 64 cm/s (32-141, 67 %), and EDV 35 cm/s (18-55, 42 %); in the right ACA, HF was 154 ml/min (42-246, 49 %), LF 77 ml/min (0-156, 131 %), PSV 75 cm/s (26-161, 82 %), and EDV 39 cm/s (7-59, 67 %). In the left MCA, HF was 235 ml/min (126-372, 35 %), LF 116 ml/min (42-186, 48 %), PSV 90 cm/s (55-183, 39 %), and EDV 46 cm/s (20-66, 28 %); in the right MCA, HF was 238 ml/min (162-342, 44 %), LF 120 ml/min (72-216, 48 %), PSV 88 cm/s (55-141, 35 %), and EDV 45 cm/s (26-67, 23 %). In the left PCA, HF was 108 ml/min (42-168, 54 %), LF 53 ml/min (18-108, 64 %), PSV 50 cm/s (24-77, 63 %), and EDV 28 cm/s (14-40, 45 %); in the right PCA, HF was 98 ml/min (30-162, 49 %), LF 49 ml/min (12-84, 55 %), PSV 47 cm/s (27-88, 59 %), and EDV 27 cm/s (16-41, 45 %). CONCLUSION PC-MRI-measured flow and velocity parameters in the main intracranial arteries have large normal ranges. Reproducibility is highest in MCA.
Collapse
|
29
|
Promelle V, Daouk J, Bouzerar R, Jany B, Milazzo S, Balédent O. Ocular blood flow and cerebrospinal fluid pressure in glaucoma. Acta Radiol Open 2016; 5:2058460115624275. [PMID: 26962460 PMCID: PMC4765818 DOI: 10.1177/2058460115624275] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 12/01/2015] [Indexed: 11/08/2022] Open
Abstract
Disease mechanism underlying glaucoma remains unclear. Extensive research on this pathology has highlighted changes in vascular parameters and in circulation of the cerebrospinal fluid (CSF). Here, we review the most recent research on alterations in ocular blood flow and/or CSF flow in glaucoma. Ultrasound Doppler imaging studies have shown an increased resistive index in ophthalmic artery’s in glaucoma. Furthermore, changes in optic nerve CSF circulation, which can be assessed with magnetic resonance imaging, may lead to a greater translaminar pressure difference, mechanical stress, and poor clearance of toxic substances. This constitutes a new approach for understanding blood–CSF interactions involved in glaucoma.
Collapse
Affiliation(s)
- Véronique Promelle
- Ophthalmology Department, Amiens University Medical Center, Amiens, France
| | - Joël Daouk
- Bioflow Image Unit, Jules Verne University of Picardie, Amiens, France
| | - Roger Bouzerar
- Bioflow Image Unit, Jules Verne University of Picardie, Amiens, France; Medical Image Processing Unit, Amiens University Medical Center, Amiens, France
| | - Benjamin Jany
- Ophthalmology Department, Amiens University Medical Center, Amiens, France
| | - Solange Milazzo
- Ophthalmology Department, Amiens University Medical Center, Amiens, France
| | - Olivier Balédent
- Bioflow Image Unit, Jules Verne University of Picardie, Amiens, France; Medical Image Processing Unit, Amiens University Medical Center, Amiens, France
| |
Collapse
|
30
|
Barton M, Marecek R, Rektor I, Filip P, Janousova E, Mikl M. Sensitivity of PPI analysis to differences in noise reduction strategies. J Neurosci Methods 2015; 253:218-32. [DOI: 10.1016/j.jneumeth.2015.06.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 06/29/2015] [Accepted: 06/30/2015] [Indexed: 11/30/2022]
|
31
|
Kim DJ, Czosnyka M, Kim H, Balédent O, Smielewski P, Garnett MR, Czosnyka Z. Phase-shift between arterial flow and ICP pulse during infusion test. Acta Neurochir (Wien) 2015; 157:633-8. [PMID: 25646851 DOI: 10.1007/s00701-015-2353-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 01/12/2015] [Indexed: 10/24/2022]
Abstract
BACKGROUND The dynamic relationship between pulse waveform of intracranial pressure (ICP) and transcranial Doppler (TCD) cerebral blood flow velocity (CBFV) may contain information about cerebrospinal compliance. This study investigated the possibility by focusing on the phase shift between fundamental harmonics of CBFV and ICP. METHODS Thirty-seven normal pressure hydrocephalus patients (20 men, mean age 58) underwent the cerebrospinal fluid (CSF) infusion tests. The infusion was performed via pre-implanted Ommaya reservoir. The TCD FV was recorded in the middle cerebral artery. Resulting continuous ICP and pressure-volume (PV) signals were analyzed by ICM+ software. RESULTS In initial stage of the CSF infusion, the phase shift was negative (median value = -11°, range = +60 to -117). There was significant inverse association of phase shift with brain elasticity (R = -0.51; p = 0.0009). In all tests, phase shift consistently decreased during gradual elevation of ICP (p = 0.00001). Magnitude of decrease in phase shift was inversely related to the peak-to-peak amplitude of ICP pulse waveform at a baseline (R = -0.51; p = 0.001). CONCLUSIONS Phase shift between fundamental harmonics of ICP and TCD waveforms decreases during elevation of ICP. This is caused by an increase of time delay between systolic peak of flow velocity wave and ICP pulse.
Collapse
|
32
|
Transfer characteristics of arterial pulsatile force in regional intracranial tissue using dynamic diffusion MRI: A phantom study. Magn Reson Imaging 2014; 32:1284-9. [DOI: 10.1016/j.mri.2014.08.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 07/29/2014] [Accepted: 08/21/2014] [Indexed: 11/21/2022]
|
33
|
Capel C, Makki M, Gondry-Jouet C, Bouzerar R, Courtois V, Krejpowicz B, Balédent O. Insights into cerebrospinal fluid and cerebral blood flows in infants and young children. J Child Neurol 2014; 29:1608-15. [PMID: 24346313 DOI: 10.1177/0883073813511854] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This study investigates the craniospinal flows of blood and cerebrospinal fluid using phase-contrast magnetic resonance imaging (MRI) on 23 control neonates and infants (5 d-68 mo old). Mean arterial cerebral blood flow increased with age of infant from 180 mL/min after birth to 1330 mL/min around 6 years of age. This corresponds to 51 mL/min/100 g and 95 mL/min/100 g, respectively. Cervical cerebrospinal fluid stroke volume increased from 38 × 10(-3) mL to 752 × 10(-3) mL per cardiac cycle. After arterial systolic blood inflow, we observed a delay of the venous outflow that was always preceded by cerebrospinal fluid flushing out through the spinal canal. These results highlighted the importance of compliance of the spinal compartment and the interaction of blood and cerebrospinal fluid dynamics. The capacity of the spinal compartment to receive intracranial cerebrospinal fluid in presence of fontanels was demonstrated. We provide reference values to understand the physiology of cerebrospinal fluid and cerebral blood.
Collapse
Affiliation(s)
- Cyrille Capel
- Image Processing Unit, University Hospital, Amiens, France Bio Flow Image, Research group of Picardie Jules Verne, France Neurosurgery Unit, University Hospital, Amiens, France
| | - Malek Makki
- MRI Research, University Children Hospital, Zurich, Switzerland
| | - Catherine Gondry-Jouet
- Bio Flow Image, Research group of Picardie Jules Verne, France Radiology Unit, University Hospital, Amiens, France
| | - Roger Bouzerar
- Image Processing Unit, University Hospital, Amiens, France Bio Flow Image, Research group of Picardie Jules Verne, France
| | - Véronique Courtois
- Ostéobio, Ecole supérieure d'ostéopathie et de biomécanique, Paris, France
| | | | - Olivier Balédent
- Image Processing Unit, University Hospital, Amiens, France Bio Flow Image, Research group of Picardie Jules Verne, France
| |
Collapse
|
34
|
Coverdale NS, Gati JS, Opalevych O, Perrotta A, Shoemaker JK. Cerebral blood flow velocity underestimates cerebral blood flow during modest hypercapnia and hypocapnia. J Appl Physiol (1985) 2014; 117:1090-6. [DOI: 10.1152/japplphysiol.00285.2014] [Citation(s) in RCA: 246] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To establish the accuracy of transcranial Doppler ultrasound (TCD) measures of middle cerebral artery (MCA) cerebral blood flow velocity (CBFV) as a surrogate of cerebral blood flow (CBF) during hypercapnia (HC) and hypocapnia (HO), we examined whether the cross-sectional area (CSA) of the MCA changed during HC or HO and whether TCD-based estimates of CBFV were equivalent to estimates from phase contrast (PC) magnetic resonance imaging. MCA CSA was measured from 3T magnetic resonance images during baseline, HO (hyperventilation at 30 breaths/min), and HC (6% carbon dioxide). PC and TCD measures of CBFV were measured during these protocols on separate days. CSA and TCD CBFV were used to calculate CBF. During HC, CSA increased from 5.6 ± 0.8 to 6.5 ± 1.0 mm2 ( P < 0.001, n = 13), while end-tidal carbon dioxide partial pressure (PetCO2) increased from 37 ± 3 to 46 ± 5 Torr ( P < 0.001). During HO, CSA decreased from 5.8 ± 0.9 to 5.3 ± 0.9 mm2 ( P < 0.001, n = 15), while PetCO2 decreased from 36 ± 4 to 23 ± 3 Torr ( P < 0.001). CBFVs during baseline, HO, and HC were compared between PC and TCD, and the intraclass correlation coefficient was 0.83 ( P < 0.001). The relative increase from baseline was 18 ± 8% greater ( P < 0.001) for CBF than TCD CBFV during HC, and the relative decrease of CBF during HO was 7 ± 4% greater than the change in TCD CBFV ( P < 0.001). These findings challenge the assumption that the CSA of the MCA does not change over modest changes in PetCO2.
Collapse
Affiliation(s)
- Nicole S. Coverdale
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada
| | - Joseph S. Gati
- Robarts Research Institute, Western University, London, Ontario, Canada; and
| | - Oksana Opalevych
- Robarts Research Institute, Western University, London, Ontario, Canada; and
| | - Amanda Perrotta
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada
| | - J. Kevin Shoemaker
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| |
Collapse
|
35
|
Benathan-Tordjmann J, Bailly P, Meyer ME, Daouk J. Cerebral arterial inflow assessment with 18F-FDG PET: methodology and feasibility. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2014; 116:177-183. [PMID: 25015567 DOI: 10.1016/j.cmpb.2014.06.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 06/12/2014] [Accepted: 06/17/2014] [Indexed: 06/03/2023]
Abstract
Positron emission tomography (PET) with 18fluorodeoxyglucose (18F-FDG) is increasingly used in neurology. The measurement of cerebral arterial inflow (QA) using 18F-FDG complements the information provided by standard brain PET imaging. Here, injections were performed after the beginning of dynamic acquisitions and the time to arrival (t0) of activity in the gantry's field of view was computed. We performed a phantom study using a branched tube (internal diameter: 4mm) and a 18F-FDG solution injected at 240 mL/min. Data processing consisted of (i) reconstruction of the first 3s after t0, (ii) vascular signal enhancement and (iii) clustering. This method was then applied in four subjects. We measured the volumes of the tubes or vascular trees and calculated the corresponding flows. In the phantom, the flow was calculated to be 244.2 mL/min. In each subject, our QA value was compared with that obtained by quantitative cine-phase contrast magnetic resonance imaging; the mean QA value of 581.4±217.5 mL/min calculated with 18F-FDG PET was consistent with the mean value of 593.3±205.8 mL/min calculated with quantitative cine-phase contrast magnetic resonance imaging. Our 18F-FDG PET method constitutes a novel, fully automatic means of measuring QA.
Collapse
Affiliation(s)
- Jennifer Benathan-Tordjmann
- Service de médecine nucléaire et de traitement de l'image médicale, Centre Hospitalier Universitaire d'Amiens, Amiens, France
| | - Pascal Bailly
- Service de médecine nucléaire et de traitement de l'image médicale, Centre Hospitalier Universitaire d'Amiens, Amiens, France.
| | - Marc-Etienne Meyer
- Service de médecine nucléaire et de traitement de l'image médicale, Centre Hospitalier Universitaire d'Amiens, Amiens, France; Université de Picardie Jules Verne, Amiens, France
| | - Joël Daouk
- Université de Picardie Jules Verne, Amiens, France
| |
Collapse
|
36
|
Perez JJ. To what extent is the bipolar rheoencephalographic signal contaminated by scalp blood flow? A clinical study to quantify its extra and non-extracranial components. Biomed Eng Online 2014; 13:131. [PMID: 25192886 PMCID: PMC4169836 DOI: 10.1186/1475-925x-13-131] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 08/30/2014] [Indexed: 11/16/2022] Open
Abstract
Background Impedance plethysmography applied to the head by using a pair of electrodes attached to the scalp surface is known as bipolar Rheoencephalography or REG I and was originally proposed to measure changes in cerebral blood volume related to the heartbeat. REG I was soon discarded in favor of other REG configurations, since most of the signal was shown to be heavily contaminated by the extracranial blood flow. The main goal of this study was to identify and compare the part of the REG I signal caused by scalp blood flow with that originating from non-extracranial sources. Methods A clinical study involving thirty-six healthy volunteers was designed for this purpose. REG I was first registered in each subject under normal conditions. A pneumatic cuff was then placed around the head and was inflated to arrest the scalp blood flow and a second REG I was recorded. Finally, a third REG I was taken immediately after cuff deflation. Results The REG I signal is attenuated, but not extinguished, during cuff inflation in a wide subject-dependent range ratio from 0.12 to 0.68 (0.37 ± 0.15). The residual REG I signal has a waveform that is markedly different from that obtained before cuff inflation, which supports the hypothesis of the intracranial origin of the residual REG I signal. Additionally, an increase of 22% in REG I amplitude was observed when the head cuff was deflated. Conclusions Waveform differences between extra and non-extracranial components are significant and these differences could be used in a method to distinguish one from the other. However, a significant part of the REG I signal is caused by a non-extracranial source and, therefore, it should not be used as a footprint of the extracranial blood flow.
Collapse
Affiliation(s)
- Juan J Perez
- Bioelectronic Research Group (I3BH) (Ed, 7F), Universitat Politècnica de València, Cno de Vera s/n, Valencia, Spain.
| |
Collapse
|
37
|
CSF dynamic analysis of a predictive pulsatility-based infusion test for normal pressure hydrocephalus. Med Biol Eng Comput 2013; 52:75-85. [DOI: 10.1007/s11517-013-1110-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 09/01/2013] [Indexed: 10/26/2022]
|
38
|
ElSankari S, Balédent O, van Pesch V, Sindic C, de Broqueville Q, Duprez T. Concomitant analysis of arterial, venous, and CSF flows using phase-contrast MRI: a quantitative comparison between MS patients and healthy controls. J Cereb Blood Flow Metab 2013; 33:1314-21. [PMID: 23778162 PMCID: PMC3764393 DOI: 10.1038/jcbfm.2013.95] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Revised: 04/16/2013] [Accepted: 04/17/2013] [Indexed: 01/30/2023]
Abstract
Venous dysfunction has recently been hypothesized to contribute to the pathophysiology of multiple sclerosis (MS). 2D phase-contrast (PC) magnetic resonance imaging (MRI) is a non-invasive and innocuous technique enabling reliable quantification of cerebrospinal fluid (CSF) and blood flows in the same imaging session. We compared PC-MRI measurements of CSF, arterial and venous flows in MS patients to those from a normative cohort of healthy controls (HC). Nineteen MS patients underwent a standardized MR protocol for cerebral examination on a 3T system including Fast cine PC-MRI sequences with peripheral gating in four acquisition planes. Quantitative data were processed using a homemade software to extract CSF and blood flow regions of interest, animate flows, and calculate cervical and intracranial vascular flow curves during the cardiac cycle (CC). Results were compared with values obtained in 21 HC using multivariate analysis. Venous flow patterns were comparable in both groups without signs of reflux. Arterial flows (P=0.02) and cervical CSF dynamic oscillations (P=0.01) were decreased in MS patients. No significant differences in venous cerebral and cervical outflows were observed between groups, thereby contradicting the recently proposed theory of venous insufficiency. Unexpected decrease in arterial perfusion in MS patients warrants further correlation to volumetric measurements of the brain.
Collapse
Affiliation(s)
- Souraya ElSankari
- Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
| | | | | | | | | | | |
Collapse
|
39
|
Kim DJ, Carrera E, Czosnyka M, Keong N, Smielewski P, Balédent O, Sutcliffe MPF, Pickard JD, Czosnyka Z. Cerebrospinal compensation of pulsating cerebral blood volume in hydrocephalus. Neurol Res 2013; 32:587-92. [DOI: 10.1179/174313209x455673] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
40
|
Anile C, Bonis PD, Ficola A, Santini P, Mangiola A. An experimental study on artificially induced CSF pulse waveform morphological modifications. Neurol Res 2013; 33:1072-82. [DOI: 10.1179/1743132811y.0000000056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
41
|
Optimal individual inversion time in brain arterial spin labeling perfusion magnetic resonance imaging: correlation with carotid hemodynamics measured with cine phase-contrast magnetic resonance imaging. J Comput Assist Tomogr 2013; 37:247-51. [PMID: 23493214 DOI: 10.1097/rct.0b013e31827cd548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The quantification of cerebral blood flow using pulsed arterial spin labeling could be erroneous with a nonoptimal inversion time (TI). We suggest that the optimal individual TI is dependent on the hemodynamic values of the supra-aortic vessels. METHODS Twenty-two healthy volunteers (mean age, 31.8 years) underwent 7 pulsed arterial spin labeling scans at 3 T with TI ranging from 1200 to 1800 milliseconds every 100 milliseconds. The quantitative hemodynamic values of carotids were computed using a cine phase-contrast sequence. Optimal TIs were determined using visual and quantitative criteria. A correlation was sought between each optimal individual TI criterion and the hemodynamic parameter values. RESULTS The optimal group TI was 1700 milliseconds. The individual analysis showed a significant correlation between the optimal TI of white matter signal-to-noise ratio and stroke distance, and the optimal TI of contrast-to-noise ratio with mean velocity. CONCLUSIONS A correlation was found between optimal individual TIs and carotid hemodynamic parameters.
Collapse
|
42
|
Dynamics of hydrocephalus: a physical approach. J Biol Phys 2013; 38:251-66. [PMID: 23449459 DOI: 10.1007/s10867-011-9239-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 08/23/2011] [Indexed: 10/17/2022] Open
Abstract
As brain ventricles lose their ability to regulate the cerebrospinal fluid (CSF) pressure, serious brain conditions collectively named hydrocephalus can appear. By modelling ventricular dynamics with the laws of physics, dynamical instabilities are evidenced, caused by either CSF transport dysregulations or abnormal properties of the elasticity of the ependyma. We show that these instabilities would lead, in most cases, to dilation of the ventricles, establishing a close connection to hydrocephalus, or in some other cases to a ventricular contraction as observed in the slit ventricle syndrome. Signs seem to indicate the possibility of phase transitions occurring as a result of these instabilities, which might have important clinical consequences, such as the inability to recover a healthy state. Even so, our dynamical approach could allow the development of a unified view of these complex intracranial conditions along with a classification that might be clinically relevant.
Collapse
|
43
|
de Riva N, Budohoski KP, Smielewski P, Kasprowicz M, Zweifel C, Steiner LA, Reinhard M, Fábregas N, Pickard JD, Czosnyka M. Transcranial Doppler pulsatility index: what it is and what it isn't. Neurocrit Care 2012; 17:58-66. [PMID: 22311229 DOI: 10.1007/s12028-012-9672-6] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Transcranial Doppler (TCD) pulsatility index (PI) has traditionally been interpreted as a descriptor of distal cerebrovascular resistance (CVR). We sought to evaluate the relationship between PI and CVR in situations, where CVR increases (mild hypocapnia) and decreases (plateau waves of intracranial pressure-ICP). METHODS Recordings from patients with head-injury undergoing monitoring of arterial blood pressure (ABP), ICP, cerebral perfusion pressure (CPP), and TCD assessed cerebral blood flow velocities (FV) were analyzed. The Gosling pulsatility index (PI) was compared between baseline and ICP plateau waves (n = 20 patients) or short term (30-60 min) hypocapnia (n = 31). In addition, a modeling study was conducted with the "spectral" PI (calculated using fundamental harmonic of FV) resulting in a theoretical formula expressing the dependence of PI on balance of cerebrovascular impedances. RESULTS PI increased significantly (p < 0.001) while CVR decreased (p < 0.001) during plateau waves. During hypocapnia PI and CVR increased (p < 0.001). The modeling formula explained more than 65% of the variability of Gosling PI and 90% of the variability of the "spectral" PI (R = 0.81 and R = 0.95, respectively). CONCLUSION TCD pulsatility index can be easily and quickly assessed but is usually misinterpreted as a descriptor of CVR. The mathematical model presents a complex relationship between PI and multiple haemodynamic variables.
Collapse
Affiliation(s)
- Nicolás de Riva
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Hills Road, Box 167, Cambridge, CB2 0QQ, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Leung J, Behpour A, Sokol N, Mohanta A, Kassner A. Assessment of intracranial blood flow velocities using a computer controlled vasoactive stimulus: A comparison between phase contrast magnetic resonance angiography and transcranial doppler ultrasonography. J Magn Reson Imaging 2012; 38:733-8. [DOI: 10.1002/jmri.23911] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 09/25/2012] [Indexed: 11/11/2022] Open
Affiliation(s)
- Jackie Leung
- Department of Physiology and Experimental Medicine; Hospital for Sick Children Toronto; Ontario; Canada
| | | | - Neil Sokol
- Department of Medical Imaging; University of Toronto; Toronto, Ontario; Canada
| | - Arun Mohanta
- Diagnostic Imaging, Hospital for Sick Children; Toronto, Ontario; Canada
| | | |
Collapse
|
45
|
Elsankari S, Czosnyka M, Lehmann P, Meyer ME, Deramond H, Balédent O. Cerebral Blood and CSF Flow Patterns in Patients Diagnosed for Cerebral Venous Thrombosis - An Observational Study. J Clin Imaging Sci 2012; 2:41. [PMID: 22919555 PMCID: PMC3424687 DOI: 10.4103/2156-7514.99158] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 04/14/2012] [Indexed: 12/05/2022] Open
Abstract
Background and Purpose: Recent studies of the organization of the cerebral venous system in healthy subjects using phase contrast magnetic resonance imaging (PC-MRI) show its structural complexity and inter-individual variations. Our objective was to study the venous blood and CSF flows in cerebral venous thrombosis (CVT). Materials and Methods: PC-MRI sequences were added to brain MRI conventional protocol in 19 patients suspected of CVT, among whom 6 patients had CVT diagnosis confirmed by MR venography. Results were compared with 18 healthy age-matched volunteers (HV). Results: In patients without CVT (NoCVT) confirmed by venography, we found heterogeneous individual venous flows, and variable side dominance in paired veins and sinuses, comparable to those in healthy volunteers. In CVT patients, PC-MRI detected no venous flow in the veins and/or sinuses with thrombosis. Arterial flows were preserved. CSF aqueductal and cervical stroke volumes were increased in a patient with secondary cerebral infarction, and decreased in 4 patients with extended thrombosis in the superior sagittal and transverse sinuses. These results suggest the main role of the venous system in the regulation of the dynamic intracranial equilibrium. Conclusions: CVT produces highly individualized pattern of disturbance in venous blood drainage. Complementary to MRI venography, PC-MRI provides non-invasive data about venous blockage consequences on CSF flow disturbances.
Collapse
Affiliation(s)
- Souraya Elsankari
- Department of Imaging and Biophysics, Amiens University Hospital, 80054 Amiens Cedex, France
| | | | | | | | | | | |
Collapse
|
46
|
Schneiders JJ, Ferns SP, van Ooij P, Siebes M, Nederveen AJ, van den Berg R, van Lieshout J, Jansen G, vanBavel E, Majoie CB. Comparison of phase-contrast MR imaging and endovascular sonography for intracranial blood flow velocity measurements. AJNR Am J Neuroradiol 2012; 33:1786-90. [PMID: 22576898 DOI: 10.3174/ajnr.a3142] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Local hemodynamic information may help to stratify rupture risk of cerebral aneurysms. Patient-specific modeling of cerebral hemodynamics requires accurate data on BFV in perianeurysmal arteries as boundary conditions for CFD. The aim was to compare the BFV measured with PC-MR imaging with that obtained by using intra-arterial Doppler sonography and to determine interpatient variation in intracranial BFV. MATERIALS AND METHODS In 10 patients with unruptured intracranial aneurysms, BFV was measured in the cavernous ICA with PC-MR imaging in conscious patients before treatment, and measured by using an intra-arterial Doppler sonography wire when the patient was anesthetized with either propofol (6 patients) or sevoflurane (4 patients). RESULTS Both techniques identified a pulsatile blood flow pattern in cerebral arteries. PSV differed >50 cm/s between patients. A mean velocity of 41.3 cm/s (95% CI, 39.3-43.3) was measured with PC-MR imaging. With intra-arterial Doppler sonography, a mean velocity of 29.3 cm/s (95% CI, 25.8-32.8) was measured with the patient under propofol-based intravenous anesthesia. In patients under sevoflurane-based inhaled anesthesia, a mean velocity of 44.9 cm/s (95% CI, 40.6-49.3) was measured. CONCLUSIONS We showed large differences in BFV between patients, emphasizing the importance of using patient-specific hemodynamic boundary conditions in CFD. PC-MR imaging measurements of BFV in conscious patients were comparable with those obtained with the intra-arterial Doppler sonography when the patient was anesthetized with a sevoflurane-based inhaled anesthetic.
Collapse
Affiliation(s)
- J J Schneiders
- Department of Radiology, Academic Medical Center, University of Amsterdam, the Netherlands.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
|
48
|
Magnetic resonance velocity mapping of 3D cerebrospinal fluid flow dynamics in hydrocephalus: preliminary results. Eur Radiol 2011; 22:232-42. [DOI: 10.1007/s00330-011-2247-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/21/2011] [Accepted: 07/08/2011] [Indexed: 10/17/2022]
|
49
|
Effects of inflow and radiofrequency spoiling on the arterial input function in dynamic contrast-enhanced MRI: A combined phantom and simulation study. Magn Reson Med 2011; 65:1670-9. [DOI: 10.1002/mrm.22760] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 11/04/2010] [Accepted: 11/24/2010] [Indexed: 02/04/2023]
|
50
|
Chang W, Landgraf B, Johnson KM, Kecskemeti S, Wu Y, Velikina J, Rowley H, Wieben O, Mistretta C, Turski P. Velocity measurements in the middle cerebral arteries of healthy volunteers using 3D radial phase-contrast HYPRFlow: comparison with transcranial Doppler sonography and 2D phase-contrast MR imaging. AJNR Am J Neuroradiol 2011; 32:54-9. [PMID: 20947642 DOI: 10.3174/ajnr.a2240] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE We have developed PC HYPRFlow, a comprehensive MRA technique that includes a whole-brain CE dynamic series followed by PC velocity-encoding, yielding a time series of high-resolution morphologic angiograms with associated velocity information. In this study, we present velocity data acquired by using the PC component of PC HYPRFlow (PC-VIPR). MATERIALS AND METHODS Ten healthy volunteers (6 women, 4 men) were scanned by using PC HYPRFlow and 2D-PC imaging, immediately followed by velocity measurements by using TCD. Velocity measurements were made in the M1 segments of the MCAs from the PC-VIPR, 2D-PC, and TCD examinations. RESULTS PC-VIPR showed approximately 30% lower mean velocity compared with TCD, consistent with other comparisons of TCD with PC-MRA. The correlation with TCD was r = 0.793, and the correlation of PC-VIPR with 2D-PC was r = 0.723. CONCLUSIONS PC-VIPR is a technique capable of acquiring high-resolution MRA of diagnostic quality with velocity data comparable with TCD and 2D-PC. The combination of velocity information and fast high-resolution whole-brain morphologic angiograms makes PC HYPRFlow an attractive alternative to current MRA methods.
Collapse
Affiliation(s)
- W Chang
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|