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Mamiya T, Araki Y, Taoka T, Fujita N, Yokoyama K, Uda K, Muraoka S, Kanamori F, Takayanagi K, Ishii K, Nishihori M, Izumi T, Kato K, Saito R. Characteristics of donor vessels and cerebral blood flow in the chronic phase after combined revascularization surgery for moyamoya disease. Clin Neurol Neurosurg 2024; 236:108110. [PMID: 38171051 DOI: 10.1016/j.clineuro.2023.108110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 01/05/2024]
Abstract
OBJECTIVE This study aimed to analyze whether the development of donor vessels after combined revascularization surgery for moyamoya disease (MMD) is related to cerebral blood flow (CBF) changes. METHODS We retrospectively reviewed the charts of 11 adult (12 hemispheres) and 13 pediatric (19 hemispheres) patients who underwent combined revascularization in our department. The total vessel cross-sectional area (TVA) was the sum of the cross-sectional areas of the superficial temporal, middle meningeal, and deep temporal arteries imaged using time-of-flight magnetic resonance angiography. The ipsilateral relative CBF (RCBF) on the brain surface in the craniotomy area was calculated by single-photon emission computed tomography. ΔTVA and ΔRCBF were defined as the preoperative and postoperative ratios of TVA and RCBF, and their correlations were analyzed in adult and pediatric patients. RESULTS The TVA and RCBF showed a significant increase after surgery, regardless of the age group. However, there was no significant correlation between ΔTVA and ΔRCBF in either the adult or pediatric groups. While the adult group exhibited significantly higher ΔRCBF values compared to the pediatric group (p < 0.01, r = -0.44), the ΔTVA values were higher in the pediatric group compared to the adult group (p = 0.06). CONCLUSIONS In the chronic phase after combined revascularization surgery for MMD, the development of measurable TVA of donor vessels does not necessarily correlate with an increase in CBF around the craniotomy area.
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Affiliation(s)
- Takashi Mamiya
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan.
| | - Yoshio Araki
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
| | - Toshiaki Taoka
- Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
| | - Naotoshi Fujita
- Department of Radiological Technology, Nagoya University Hospital, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, Japan
| | - Kinya Yokoyama
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
| | - Kenji Uda
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
| | - Shinsuke Muraoka
- Department of Neurosurgery, Tosei General Hospital, Seto, Aichi, Japan
| | - Fumiaki Kanamori
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
| | - Kai Takayanagi
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
| | - Kazuki Ishii
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
| | - Masahiro Nishihori
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
| | - Takashi Izumi
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
| | - Katsuhiko Kato
- Functional Medical Imaging, Biomedical Imaging Sciences, Division of Advanced Information Health Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi, Japan
| | - Ryuta Saito
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, Japan
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Eldirdiri A, Zhuo J, Lin Z, Lu H, Gullapalli RP, Jiang D. Toward vendor-independent measurement of cerebral venous oxygenation: Comparison of TRUST MRI across three major MRI manufacturers and association with end-tidal CO 2. NMR IN BIOMEDICINE 2023; 36:e4990. [PMID: 37315951 PMCID: PMC10801912 DOI: 10.1002/nbm.4990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/29/2023] [Accepted: 05/30/2023] [Indexed: 06/16/2023]
Abstract
Cerebral venous oxygenation (Yv ) is a valuable biomarker for a variety of brain diseases. T2 relaxation under spin tagging (TRUST) MRI is a widely used method for Yv quantification. In this work, there were two main objectives. The first was to evaluate the reproducibility of TRUST Yv measurements across MRI scanners from different vendors. The second was to examine the correlation between Yv and end-tidal CO2 (EtCO2 ) in a multisite, multivendor setting and determine the usefulness of this correlation to account for variations in Yv caused by normal variations and physiological fluctuations. Standardized TRUST pulse sequences were implemented on three scanners from major MRI vendors (GE, Siemens, Philips). These scanners were located at two research institutions. Ten healthy subjects were scanned. On each scanner, the subject underwent two scan sessions, each of which included three TRUST scans, to evaluate the intrasession and intersession reproducibility of Yv . Each scanner was also equipped with a capnograph device to record the EtCO2 of the subject during the MRI scan. We found no significant bias in Yv measurements across the three scanners (P = 0.18). The measured Yv values on the three scanners were also strongly correlated with each other (intraclass correlation coefficients > 0.85, P < 0.001). The intrasession and intersession coefficients of variation of Yv were less than 4% and showed no significant difference among the scanners. In addition, our results revealed that (1) within the same subject, Yv increased with EtCO2 at a rate of 1.24 ± 0.17%/mmHg (P < 0.0001), and (2) across different subjects, individuals with a higher EtCO2 had a higher Yv , at a rate of 0.94 ± 0.36%/mmHg (P = 0.01). These results suggest that (1) the standardized TRUST sequences had similar accuracies and reproducibilities for the quantification of Yv across the scanners, and (2) recording of EtCO2 may be a useful complement to Yv measurement to account for CO2 -related physiological fluctuations in Yv in multisite, multivendor studies.
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Affiliation(s)
- Abubakr Eldirdiri
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jiachen Zhuo
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Zixuan Lin
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hanzhang Lu
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Rao P. Gullapalli
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Dengrong Jiang
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Madsen SS, Lindberg U, Asghar S, Olsen KS, Møller K, Larsson HBW, Vestergaard MB. Reproducibility of cerebral blood flow, oxygen metabolism, and lactate and N-acetyl-aspartate concentrations measured using magnetic resonance imaging and spectroscopy. Front Physiol 2023; 14:1213352. [PMID: 37731542 PMCID: PMC10508186 DOI: 10.3389/fphys.2023.1213352] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/21/2023] [Indexed: 09/22/2023] Open
Abstract
In humans, resting cerebral perfusion, oxygen consumption and energy metabolism demonstrate large intersubject variation regardless of methodology. Whether a similar large variation is also present longitudinally in individual subjects is much less studied, but knowing the time variance in reproducibility is important when designing and interpreting longitudinal follow-up studies examining brain physiology. Therefore, we examined the reproducibility of cerebral blood flow (CBF), global cerebral metabolic rate of oxygen (CMRO2), global arteriovenous oxygen saturation difference (A-V.O2), and cerebral lactate and N-acetyl-aspartate (NAA) concentrations measured using magnetic resonance imaging (MRI) and spectroscopy (MRS) techniques through repeated measurements at 6 h, 24 h, 7 days and several weeks after initial baseline measurements in young healthy adults (N = 26, 13 females, age range 18-35 years). Using this setup, we calculated the correlation, limit of agreement (LoA) and within-subject coefficient of variation (CoVWS) between baseline values and the subsequent repeated measurements to examine the longitudinal variation in individual cerebral physiology. CBF and CMRO2 correlated significantly between baseline and all subsequent measurements. The strength of the correlations (R2) and reproducibility metrics (LoA and CoVWS) demonstrated the best reproducibility for the within-day measurements and generally declined with longer time between measurements. Cerebral lactate and NAA concentrations also correlated significantly for all measurements, except between baseline and the 7-day measurement for lactate. Similar to CBF and CMRO2, lactate and NAA demonstrated the best reproducibility for within-day repeated measurements. The gradual decline in reproducibility over time should be considered when designing and interpreting studies on brain physiology, for example, in the evaluation of treatment efficacy.
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Affiliation(s)
- Signe Sloth Madsen
- Department of Anaesthesiology, Pain and Respiratory Support, Neuroscience Centre, Copenhagen University Hospital–Rigshospitalet, Glostrup, Denmark
| | - Ulrich Lindberg
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
| | - Sohail Asghar
- Anesthesiology and Intensive Care, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Karsten Skovgaard Olsen
- Department of Anaesthesiology, Pain and Respiratory Support, Neuroscience Centre, Copenhagen University Hospital–Rigshospitalet, Glostrup, Denmark
| | - Kirsten Møller
- Department of Neuroanaesthesiology, Neuroscience Centre, Copenhagen University Hospital–Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Bo Wiberg Larsson
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mark Bitsch Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
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Kim D, Lipford ME, He H, Ding Q, Ivanovic V, Lockhart SN, Craft S, Whitlow CT, Jung Y. Parametric cerebral blood flow and arterial transit time mapping using a 3D convolutional neural network. Magn Reson Med 2023; 90:583-595. [PMID: 37092852 PMCID: PMC10847038 DOI: 10.1002/mrm.29674] [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: 09/27/2022] [Revised: 03/13/2023] [Accepted: 03/30/2023] [Indexed: 04/25/2023]
Abstract
PURPOSE To reduce the total scan time of multiple postlabeling delay (multi-PLD) pseudo-continuous arterial spin labeling (pCASL) by developing a hierarchically structured 3D convolutional neural network (H-CNN) that estimates the arterial transit time (ATT) and cerebral blow flow (CBF) maps from the reduced number of PLDs as well as averages. METHODS A total of 48 subjects (38 females and 10 males), aged 56-80 years, compromising a training group (n = 45) and a validation group (n = 3) underwent MRI including multi-PLD pCASL. We proposed an H-CNN to estimate the ATT and CBF maps using a reduced number of PLDs and a separately reduced number of averages. The proposed method was compared with a conventional nonlinear model fitting method using the mean absolute error (MAE). RESULTS The H-CNN provided the MAEs of 32.69 ms for ATT and 3.32 mL/100 g/min for CBF estimations using a full data set that contains six PLDs and six averages in the 3 test subjects. The H-CNN also showed that the smaller number of PLDs can be used to estimate both ATT and CBF without significant discrepancy from the reference (MAEs of 231.45 ms for ATT and 9.80 mL/100 g/min for CBF using three of six PLDs). CONCLUSION The proposed machine learning-based ATT and CBF mapping offers substantially reduced scan time of multi-PLD pCASL.
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Affiliation(s)
- Donghoon Kim
- Department of Biomedical Engineering University of California, Davis, California, USA
- Department of Radiology, University of California, Davis, California, USA
| | - Megan E. Lipford
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Hongjian He
- Center for Brain Imaging Science and Technology, College of Biomedical Engineering and Instrumental Science, Zhejiang University, China
| | - Qiuping Ding
- Center for Brain Imaging Science and Technology, College of Biomedical Engineering and Instrumental Science, Zhejiang University, China
| | - Vladimir Ivanovic
- Department of Radiology, Medical College of Wisconsin, Wisconsin, USA
| | - Samuel N. Lockhart
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Suzanne Craft
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Christopher T. Whitlow
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Youngkyoo Jung
- Department of Biomedical Engineering University of California, Davis, California, USA
- Department of Radiology, University of California, Davis, California, USA
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
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Xu F, Liu D, Zhu D, Hillis AE, Bakker A, Soldan A, Albert MS, Lin DDM, Qin Q. Test-retest reliability of 3D velocity-selective arterial spin labeling for detecting normal variations of cerebral blood flow. Neuroimage 2023; 271:120039. [PMID: 36931331 PMCID: PMC10150252 DOI: 10.1016/j.neuroimage.2023.120039] [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: 12/28/2022] [Revised: 02/23/2023] [Accepted: 03/14/2023] [Indexed: 03/18/2023] Open
Abstract
Velocity-selective inversion (VSI) based velocity-selective arterial spin labeling (VSASL) has been developed to measure cerebral blood flow (CBF) with low susceptibility to the prolonged arterial transit time and high sensitivity to brain perfusion signal. The purpose of this magnetic resonance imaging study is to evaluate the test-retest reliability of a VSI-prepared 3D VSASL protocol with whole-brain coverage to detect baseline CBF variations among cognitively normal participants in different brain regions. Coefficients of variation (CoV) of both absolute and relative CBF across scans or sessions, subjects, and gray matter regions were calculated, and corresponding intraclass correlation coefficients (ICC) were computed. The higher between-subject CoV of absolute CBF (13.4 ± 2.0%) over within-subject CoV (within-session: 3.8 ± 1.1%; between-session: 4.9 ± 0.9%) yielded moderate to excellent ICC (within-session: 0.88±0.08; between-session: 0.77±0.14) to detect normal variations of individual CBF. The higher between-region CoV of relative CBF (11.4 ± 3.0%) over within-region CoV (within-session: 2.3 ± 0.9%; between-session: 3.3 ± 1.0%) yielded excellent ICC (within-session: 0.92±0.06; between-session: 0.85±0.12) to detect normal variations of regional CBF. Age, blood pressure, end-tidal CO2, and hematocrit partially explained the variability of CBF across subjects. Together these results show excellent test-retest reliability of VSASL to detect both between-subject and between-region variations supporting its clinical utility.
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Affiliation(s)
- Feng Xu
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University, Baltimore, MD 21205, USA; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA.
| | - Dapeng Liu
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University, Baltimore, MD 21205, USA; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Dan Zhu
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University, Baltimore, MD 21205, USA; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Argye E Hillis
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Arnold Bakker
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Anja Soldan
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Marilyn S Albert
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Doris D M Lin
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Qin Qin
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University, Baltimore, MD 21205, USA; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
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Carrete LR, Young JS, Cha S. Advanced Imaging Techniques for Newly Diagnosed and Recurrent Gliomas. Front Neurosci 2022; 16:787755. [PMID: 35281485 PMCID: PMC8904563 DOI: 10.3389/fnins.2022.787755] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 01/19/2022] [Indexed: 12/12/2022] Open
Abstract
Management of gliomas following initial diagnosis requires thoughtful presurgical planning followed by regular imaging to monitor treatment response and survey for new tumor growth. Traditional MR imaging modalities such as T1 post-contrast and T2-weighted sequences have long been a staple of tumor diagnosis, surgical planning, and post-treatment surveillance. While these sequences remain integral in the management of gliomas, advances in imaging techniques have allowed for a more detailed characterization of tumor characteristics. Advanced MR sequences such as perfusion, diffusion, and susceptibility weighted imaging, as well as PET scans have emerged as valuable tools to inform clinical decision making and provide a non-invasive way to help distinguish between tumor recurrence and pseudoprogression. Furthermore, these advances in imaging have extended to the operating room and assist in making surgical resections safer. Nevertheless, surgery, chemotherapy, and radiation treatment continue to make the interpretation of MR changes difficult for glioma patients. As analytics and machine learning techniques improve, radiomics offers the potential to be more quantitative and personalized in the interpretation of imaging data for gliomas. In this review, we describe the role of these newer imaging modalities during the different stages of management for patients with gliomas, focusing on the pre-operative, post-operative, and surveillance periods. Finally, we discuss radiomics as a means of promoting personalized patient care in the future.
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Affiliation(s)
- Luis R. Carrete
- University of California San Francisco School of Medicine, San Francisco, CA, United States
| | - Jacob S. Young
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States
- *Correspondence: Jacob S. Young,
| | - Soonmee Cha
- Department of Radiology, University of California, San Francisco, San Francisco, CA, United States
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Ibaraki M, Nakamura K, Matsubara K, Shinohara Y, Kinoshita T. Effect of hematocrit on cerebral blood flow measured by pseudo-continuous arterial spin labeling MRI: A comparative study with 15O-water positron emission tomography. Magn Reson Imaging 2021; 84:58-68. [PMID: 34562565 DOI: 10.1016/j.mri.2021.09.012] [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: 03/30/2021] [Revised: 09/16/2021] [Accepted: 09/18/2021] [Indexed: 11/30/2022]
Abstract
INTRODUCTION In cerebral blood flow (CBF) quantification with pseudo-continuous arterial spin labeling (pCASL) MRI, arterial blood T1 (T1a) is usually fixed to a typical value (e.g., 1650 ms). However, individual T1a depends strongly on hematocrit (Hct) level. To investigate the utility of Hct-based T1a as an alternative to the fixed T1a method, we performed a comparative study with 15O-water positron emission tomography (PET). METHODS For patients with unilateral occlusion or stenosis of major arteries, hemispheric CBF on the healthy side was measured using pCASL and 15O-water PET. The pCASL CBFs were calculated with both (a) fixed T1a (1650 ms) and (b) individual T1a estimated from blood-sampled Hct (Hct-based T1a). Correlation coefficients of Hct-CBF were calculated and compared between pCASL and PET. RESULTS In pCASL, CBF with fixed T1a showed a strong negative correlation with Hct (r = -0.568), which was reduced with individual Hct-based T1a (r = -0.341 to -0.190), consistent with the Hct-CBF relation measured with PET (r = -0.349). DISCUSSION AND CONCLUSION We demonstrated that Hct-based T1a resulted in smaller inter-individual variations in pCASL CBF and an inverse Hct-CBF relationship more similar to that of PET. Care must be taken in the interpretation of pCASL CBF imaging in relation to Hct level even in subjects without anemia. Further comparative studies are needed to investigate whether advanced techniques improve pCASL CBF quantification at the individual level.
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Affiliation(s)
- Masanobu Ibaraki
- Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita, Japan.
| | - Kazuhiro Nakamura
- Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita, Japan.
| | - Keisuke Matsubara
- Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita, Japan.
| | - Yuki Shinohara
- Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita, Japan.
| | - Toshibumi Kinoshita
- Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita, Japan.
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Ramanaidu V, Mustapha AWMM, Noor MHM, Abdullah N. Estimation of time of death using brain parenchyma attenuation in post mortem computed tomography of brain – In malaysian setting. FORENSIC IMAGING 2021. [DOI: 10.1016/j.fri.2021.200470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Vu C, Bush A, Choi S, Borzage M, Miao X, Nederveen AJ, Coates TD, Wood JC. Reduced global cerebral oxygen metabolic rate in sickle cell disease and chronic anemias. Am J Hematol 2021; 96:901-913. [PMID: 33891719 DOI: 10.1002/ajh.26203] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 12/18/2022]
Abstract
Anemia is the most common blood disorder in the world. In patients with chronic anemia, such as sickle cell disease or major thalassemia, cerebral blood flow increases to compensate for decreased oxygen content. However, the effects of chronic anemia on oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2 ) are less well understood. In this study, we examined 47 sickle-cell anemia subjects (age 21.7 ± 7.1, female 45%), 27 non-sickle anemic subjects (age 25.0 ± 10.4, female 52%) and 44 healthy controls (age 26.4 ± 10.6, female 71%) using MRI metrics of brain oxygenation and flow. Phase contrast MRI was used to measure resting cerebral blood flow, while T2 -relaxation-under-spin-tagging (TRUST) MRI with disease appropriate calibrations were used to measure OEF and CMRO2 . We observed that patients with sickle cell disease and other chronic anemias have decreased OEF and CMRO2 (respectively 27.4 ± 4.1% and 3.39 ± 0.71 ml O2 /100 g/min in sickle cell disease, 30.8 ± 5.2% and 3.53 ± 0.64 ml O2 /100 g/min in other anemias) compared to controls (36.7 ± 6.0% and 4.00 ± 0.65 ml O2 /100 g/min). Impaired CMRO2 was proportional to the degree of anemia severity. We further demonstrate striking concordance of the present work with pooled historical data from patients having broad etiologies for their anemia. The reduced cerebral oxygen extraction and metabolism are consistent with emerging data demonstrating increased non-nutritive flow, or physiological shunting, in sickle cell disease patients.
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Affiliation(s)
- Chau Vu
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
| | - Adam Bush
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
- Department of Radiology Stanford University Stanford California USA
| | - Soyoung Choi
- Neuroscience Graduate Program University of Southern California Los Angeles California USA
| | - Matthew Borzage
- Division of Neonatology, Fetal and Neonatal Institute Children's Hospital Los Angeles Los Angeles California USA
- Department of Pediatrics, Keck School of Medicine University of Southern California Los Angeles California USA
| | - Xin Miao
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
| | - Aart J. Nederveen
- University of Amsterdam, Amsterdam UMC, Radiology and Nuclear Medicine Amsterdam The Netherlands
| | - Thomas D. Coates
- Division of Hematology‐Oncology, Department of Pediatrics Children's Hospital Los Angeles Los Angeles California USA
- Departments of Pediatrics and Pathology, Keck School of Medicine University of Southern California Los Angeles California USA
| | - John C. Wood
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
- Division of Cardiology, Departments of Pediatrics and Radiology Children's Hospital Los Angeles Los Angeles California USA
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Henriksen OM, Gjedde A, Vang K, Law I, Aanerud J, Rostrup E. Regional and interindividual relationships between cerebral perfusion and oxygen metabolism. J Appl Physiol (1985) 2021; 130:1836-1847. [PMID: 33830816 DOI: 10.1152/japplphysiol.00939.2020] [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] [Indexed: 11/22/2022] Open
Abstract
Quantitative measurements of resting cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2) show large between-subject and regional variability, but the relationships between CBF and CMRO2 measurements regionally and globally are not fully established. Here, we investigated the between-subject and regional associations between CBF and CMRO2 measures with independent and quantitative PET techniques. We included resting CBF and CMRO2 measurements from 50 healthy volunteers (aged 22-81 yr), and calculated the regional and global values of oxygen delivery (Do2) and oxygen extraction fraction (OEF). Linear mixed-model analysis showed that CBF and CMRO2 measurements were closely associated regionally, but no significant between-subject association could be demonstrated, even when adjusting for arterial Pco2 and hemoglobin concentration. The analysis also showed regional differences of OEF, reflecting variable relationship between Do2 and CMRO2, resulting in lower estimates of OEF in thalami, brainstem, and mesial temporal cortices and higher estimates of OEF in occipital cortex. In the present study, we demonstrated no between-subject association of quantitative measurements of CBF and CMRO2 in healthy subjects. Thus, quantitative measurements of CBF did not reflect the underlying between-subject variability of oxygen metabolism measures, mainly because of large interindividual OEF variability not accounted for by Pco2 and hemoglobin concentration.NEW & NOTEWORTHY Using quantitative PET-measurements in healthy human subjects, we confirmed a regional association of CBF and CMRO2, but did not find an association of these values across subjects. This suggests that subjects have an individual coupling between perfusion and metabolism and shows that absolute perfusion measurements does not serve as a surrogate measure of individual measures of oxygen metabolism. The analysis further showed smaller, but significant regional differences of oxygen extraction fraction at rest.
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Affiliation(s)
- Otto M Henriksen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Albert Gjedde
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Translational Neuropsychiatry Unit, Aarhus University and University Hospital, Aarhus, Denmark.,Department of Nuclear Medicine and PET Centre, Aarhus University and University Hospital, Aarhus, Denmark
| | - Kim Vang
- Department of Nuclear Medicine and PET Centre, Aarhus University and University Hospital, Aarhus, Denmark
| | - Ian Law
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Joel Aanerud
- Department of Nuclear Medicine and PET Centre, Aarhus University and University Hospital, Aarhus, Denmark
| | - Egill Rostrup
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark.,Mental Health Center Glostrup, University of Copenhagen, Copenhagen, Denmark
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11
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Woods JG, Chappell MA, Okell TW. Designing and comparing optimized pseudo-continuous Arterial Spin Labeling protocols for measurement of cerebral blood flow. Neuroimage 2020; 223:117246. [PMID: 32853814 PMCID: PMC7762814 DOI: 10.1016/j.neuroimage.2020.117246] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/03/2020] [Accepted: 08/05/2020] [Indexed: 01/24/2023] Open
Abstract
Arterial Spin Labeling (ASL) is a non-invasive, non-contrast, perfusion imaging technique which is inherently SNR limited. It is, therefore, important to carefully design scan protocols to ensure accurate measurements. Many pseudo-continuous ASL (PCASL) protocol designs have been proposed for measuring cerebral blood flow (CBF), but it has not yet been demonstrated which design offers the most accurate and repeatable CBF measurements. In this study, a wide range of literature PCASL protocols were first optimized for CBF accuracy and then compared using Monte Carlo simulations and in vivo experiments. The protocols included single-delay, sequential and time-encoded multi-timepoint protocols, and several novel protocol designs, which are hybrids of time-encoded and sequential multi-timepoint protocols. It was found that several multi-timepoint protocols produced more confident, accurate, and repeatable CBF estimates than the single-delay protocol, while also generating maps of arterial transit time. Of the literature protocols, the time-encoded protocol with T1-adjusted label durations gave the most confident and accurate CBF estimates in vivo (16% and 40% better than single-delay), while the sequential multi-timepoint protocol was the most repeatable (20% more repeatable than single-delay). One of the novel hybrid protocols, HybridT1-adj, was found to produce the most confident, accurate and repeatable CBF estimates out of all the protocols tested in both simulations and in vivo (24%, 47%, and 28% more confident, accurate, and repeatable than single-delay in vivo). The HybridT1-adj protocol makes use of the best aspects of both time-encoded and sequential multi-timepoint protocols and should be a useful tool for accurately and efficiently measuring CBF.
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Affiliation(s)
- Joseph G Woods
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
| | - Michael A Chappell
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Institute of Biomedical Engineering, Department of Engineering, University of Oxford, Oxford, United Kingdom
| | - Thomas W Okell
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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12
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Jiang D, Lin Z, Liu P, Sur S, Xu C, Hazel K, Pottanat G, Yasar S, Rosenberg P, Albert M, Lu H. Normal variations in brain oxygen extraction fraction are partly attributed to differences in end-tidal CO 2. J Cereb Blood Flow Metab 2020; 40:1492-1500. [PMID: 31382788 PMCID: PMC7308520 DOI: 10.1177/0271678x19867154] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cerebral oxygen extraction fraction is an important physiological index of the brain's oxygen consumption and supply and has been suggested to be a potential biomarker for a number of diseases such as stroke, Alzheimer's disease, multiple sclerosis, sickle cell disease, and metabolic disorders. However, in order for oxygen extraction fraction to be a sensitive biomarker for personalized disease diagnosis, inter-subject variations in normal subjects must be minimized or accounted for, which will otherwise obscure its interpretation. Therefore, it is essential to investigate the physiological underpinnings of normal differences in oxygen extraction fraction. This work used two studies, one discovery study and one verification study, to examine the extent to which an individual's end-tidal CO2 can explain variations in oxygen extraction fraction. It was found that, across normal subjects, oxygen extraction fraction is inversely correlated with end-tidal CO2. Approximately 50% of the inter-subject variations in oxygen extraction fraction can be attributed to end-tidal CO2 differences. In addition, oxygen extraction fraction was found to be positively associated with age and systolic blood pressure. By accounting for end-tidal CO2, age, and systolic blood pressure of the subjects, normal variations in oxygen extraction fraction can be reduced by 73%, which is expected to substantially enhance the utility of oxygen extraction fraction as a disease biomarker.
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Affiliation(s)
- Dengrong Jiang
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zixuan Lin
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peiying Liu
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sandeepa Sur
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Cuimei Xu
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kaisha Hazel
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - George Pottanat
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sevil Yasar
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Paul Rosenberg
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Marilyn Albert
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hanzhang Lu
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, USA
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13
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Vestergaard MB, Jensen MLF, Arngrim N, Lindberg U, Larsson HBW. Higher physiological vulnerability to hypoxic exposure with advancing age in the human brain. J Cereb Blood Flow Metab 2020; 40:341-353. [PMID: 30540217 PMCID: PMC6985989 DOI: 10.1177/0271678x18818291] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/26/2018] [Accepted: 11/10/2018] [Indexed: 12/14/2022]
Abstract
The aging brain is associated with atrophy along with functional and metabolic changes. In this study, we examined age-related changes in resting brain functions and the vulnerability of brain physiology to hypoxic exposure in humans in vivo. Brain functions were examined in 81 healthy humans (aged 18-62 years) by acquisitions of gray and white matter volumes, cerebral blood flow, cerebral oxygen consumption, and concentrations of lactate, N-acetylaspartate, and glutamate+glutamine using magnetic resonance imaging and spectroscopy. We observed impaired cerebral blood flow reactivity in response to inhalation of hypoxic air (p = 0.029) with advancing age along with decreased cerebral oxygen consumption (p = 0.036), and increased lactate concentration (p = 0.009), indicating tissue hypoxia and impaired metabolism. Diminished resilience to hypoxia and consequently increased vulnerability to metabolic stress could be a key part of declining brain health with age. Furthermore, we observed increased resting cerebral lactate concentration with advancing age (p = 0.007), which might reflect inhibited brain clearance of waste products.
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Affiliation(s)
- Mark B Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Mette LF Jensen
- Danish Centre for Sleep Medicine, Department of Clinical Neurophysiology, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Nanna Arngrim
- Danish Headache Centre, Department of Neurology, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Ulrich Lindberg
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Henrik BW Larsson
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
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14
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Smith LA, Melbourne A, Owen D, Cardoso MJ, Sudre CH, Tillin T, Sokolska M, Atkinson D, Chaturvedi N, Ourselin S, Hughes AD, Barkhof F, Jäger HR. Cortical cerebral blood flow in ageing: effects of haematocrit, sex, ethnicity and diabetes. Eur Radiol 2019; 29:5549-5558. [PMID: 30887200 PMCID: PMC6719435 DOI: 10.1007/s00330-019-06096-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 12/24/2018] [Accepted: 02/11/2019] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Cerebral blood flow (CBF) estimates from arterial spin labelling (ASL) show unexplained variability in older populations. We studied the impact of variation of haematocrit (Hct) on CBF estimates in a tri-ethnic elderly population. MATERIALS AND METHODS Approval for the study was obtained from the Fulham Research Ethics Committee and participants gave written informed consent. Pseudo-continuous arterial spin labelling was performed on 493 subjects (age 55-90) from a tri-ethnic community-based cohort recruited in London. CBF was estimated using a simplified Buxton equation, with and without correction for Hct measured from blood samples. Differences in perfusion were compared, stratified by sex, ethnicity and diabetes. Results of Student's t tests were reported with effect size. RESULTS Hct adjustment decreased CBF estimates in all categories except white European men. The decrease for women was 2.7 (3.0, 2.4) mL/100 g/min) (mean (95% confidence interval (CI)), p < 0.001 d = 0.38. The effect size differed by ethnicity with estimated mean perfusion in South Asian and African Caribbean women found to be lower by 3.0 (3.6, 2.5) mL/100 g/min, p < 0.001 d = 0.56 and 3.1 (3.6, 2.5) mL/100 g/min), p < 0.001 d = 0.48, respectively. Estimates of perfusion in subjects with diabetes decreased by 1.8 (2.3, 1.4) mL/100 g/min, p < 0.001 d = 0.23) following Hct correction. Correction for individual Hct altered sample frequency distributions of CBF values, especially in women of non-European ethnicity. CONCLUSION ASL-derived CBF values in women, non-European ethnicities and individuals with diabetes are overestimated if calculations are not appropriately adjusted for individual Hct. KEY POINTS • CBF quantification from ASL using a fixed Hct of 43.5%, as recommended in the ISMRM white paper, may lead to erroneous CBF estimations particularly in non-European and female subjects. • Individually measured Hct values improve the accuracy of CBF estimation and, if these are not available, an adjusted value according to gender, ethnicity or diabetes status should be considered. • Hct-corrected ASL could be potentially important for CBF threshold decision making in the fields of neurodegenerative disease and neuro-oncology.
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Affiliation(s)
- Lorna A Smith
- MRC Unit for Lifelong Health and Ageing, Department of Population Science & Experimental Medicine, University College London, WC1E 6HX, London, UK. .,Centre for Medical Imaging, Division of Medicine, University College London, 2nd Floor, Charles Bell House, 43-45 Foley Street, London, W1W 7TS, UK.
| | - Andrew Melbourne
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, SE1 7EH, UK.,Department of Medical Physics and Biomedical Engineering, University College London, London, NW1 2BU, UK
| | - David Owen
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, SE1 7EH, UK.,Department of Medical Physics and Biomedical Engineering, University College London, London, NW1 2BU, UK
| | - M Jorge Cardoso
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, SE1 7EH, UK.,Dementia Research Centre, UCL Institute of Neurology, London, Wc1N 3BG, UK
| | - Carole H Sudre
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, SE1 7EH, UK.,Department of Medical Physics and Biomedical Engineering, University College London, London, NW1 2BU, UK.,Dementia Research Centre, UCL Institute of Neurology, London, Wc1N 3BG, UK
| | - Therese Tillin
- MRC Unit for Lifelong Health and Ageing, Department of Population Science & Experimental Medicine, University College London, WC1E 6HX, London, UK
| | - Magdalena Sokolska
- Institute of Healthcare Engineering, University College London, London, UK
| | - David Atkinson
- Centre for Medical Imaging, Division of Medicine, University College London, 2nd Floor, Charles Bell House, 43-45 Foley Street, London, W1W 7TS, UK
| | - Nish Chaturvedi
- MRC Unit for Lifelong Health and Ageing, Department of Population Science & Experimental Medicine, University College London, WC1E 6HX, London, UK
| | - Sebastien Ourselin
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, SE1 7EH, UK
| | - Alun D Hughes
- MRC Unit for Lifelong Health and Ageing, Department of Population Science & Experimental Medicine, University College London, WC1E 6HX, London, UK
| | - Frederik Barkhof
- Department of Medical Physics and Biomedical Engineering, University College London, London, NW1 2BU, UK.,Dementia Research Centre, UCL Institute of Neurology, London, Wc1N 3BG, UK.,Department of Radiology & Nuclear Medicine, VU University Medical Centre, Amsterdam, Netherlands
| | - H R Jäger
- Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, WC1N 3BG, UK.,Lysholm Department of Neuroradiology, The National Hospital for Neurology and Neurosurgery, University College London, London, WCN1 3BG, UK
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15
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Clement P, Mutsaerts HJ, Václavů L, Ghariq E, Pizzini FB, Smits M, Acou M, Jovicich J, Vanninen R, Kononen M, Wiest R, Rostrup E, Bastos-Leite AJ, Larsson EM, Achten E. Variability of physiological brain perfusion in healthy subjects - A systematic review of modifiers. Considerations for multi-center ASL studies. J Cereb Blood Flow Metab 2018; 38:1418-1437. [PMID: 28393659 PMCID: PMC6120130 DOI: 10.1177/0271678x17702156] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Quantitative measurements of brain perfusion are influenced by perfusion-modifiers. Standardization of measurement conditions and correction for important modifiers is essential to improve accuracy and to facilitate the interpretation of perfusion-derived parameters. An extensive literature search was carried out for factors influencing quantitative measurements of perfusion in the human brain unrelated to medication use. A total of 58 perfusion modifiers were categorized into four groups. Several factors (e.g., caffeine, aging, and blood gases) were found to induce a considerable effect on brain perfusion that was consistent across different studies; for other factors, the modifying effect was found to be debatable, due to contradictory results or lack of evidence. Using the results of this review, we propose a standard operating procedure, based on practices already implemented in several research centers. Also, a theory of 'deep MRI physiotyping' is inferred from the combined knowledge of factors influencing brain perfusion as a strategy to reduce variance by taking both personal information and the presence or absence of perfusion modifiers into account. We hypothesize that this will allow to personalize the concept of normality, as well as to reach more rigorous and earlier diagnoses of brain disorders.
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Affiliation(s)
- Patricia Clement
- 1 Department of Radiology and nuclear medicine, Ghent University, Ghent, Belgium
| | - Henk-Jan Mutsaerts
- 2 Cognitive Neurology Research Unit, Sunnybrook Healthy Sciences Centre, Toronto, Canada.,3 Academic Medical Center, Amsterdam, the Netherlands
| | - Lena Václavů
- 3 Academic Medical Center, Amsterdam, the Netherlands
| | - Eidrees Ghariq
- 4 Leiden University Medical Center, Leiden, the Netherlands
| | | | | | - Marjan Acou
- 1 Department of Radiology and nuclear medicine, Ghent University, Ghent, Belgium
| | - Jorge Jovicich
- 7 Magnetic Resonance Imaging Laboratory Center for Mind/Brain Sciences, University of Trento, Mattarello, Italy
| | | | | | | | - Egill Rostrup
- 10 Department of Diagnostics, Glostrup Hospital, University of Copenhagen, Denmark
| | | | | | - Eric Achten
- 1 Department of Radiology and nuclear medicine, Ghent University, Ghent, Belgium
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16
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Delgado AF, De Luca F, Hanagandi P, van Westen D, Delgado AF. Arterial Spin-Labeling in Children with Brain Tumor: A Meta-Analysis. AJNR Am J Neuroradiol 2018; 39:1536-1542. [PMID: 30072368 PMCID: PMC7410530 DOI: 10.3174/ajnr.a5727] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/18/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND The value of arterial spin-labeling in a pediatric population has not been assessed in a meta-analysis. PURPOSE Our aim was to assess the diagnostic accuracy of arterial spin-labeling-derived cerebral blood flow to discriminate low- and high-grade tumors. DATA SOURCES MEDLINE, EMBASE, the Web of Science Core Collection, and the Cochrane Library were used. STUDY SELECTION Pediatric patients with arterial spin-labeling MR imaging with verified neuropathologic diagnoses were included. DATA ANALYSIS Relative CBF and absolute CBF and tumor grade were extracted, including sequence-specific information. Mean differences in CBF between low- and high-grade tumors were calculated. Study quality was assessed. DATA SYNTHESIS Data were aggregated using the bivariate summary receiver operating characteristic curve model. Heterogeneity was explored with meta-regression and subgroup analyses. The study protocol was published at PROSPERO (CRD42017075055). Eight studies encompassing 286 pediatric patients were included. The mean differences in absolute CBF were 29.62 mL/min/100 g (95% CI, 10.43-48.82 mL/min/100 g), I2 = 74, P = .002, and 1.34 mL/min/100 g (95% CI, 0.95-1.74 mL/min/100 g), P < .001, I2 = 38 for relative CBF. Pooled sensitivity for relative CBF ranged from 0.75 to 0.90, and specificity, from 0.77 to 0.92 with an area under curve = 0.92. Meta-regression showed no moderating effect of sequence parameters TE, TR, acquisition time, or ROI method. LIMITATIONS Included tumor types, analysis method, and original data varied among included studies. CONCLUSIONS Arterial spin-labeling-derived CBF measures showed high diagnostic accuracy for discriminating low- and high-grade tumors in pediatric patients with brain tumors. The relative CBF showed less variation among studies than the absolute CBF.
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Affiliation(s)
- A F Delgado
- From the Departments of Clinical Neuroscience (Anna F.D.)
| | - F De Luca
- Faculty of Medicine and Surgery (F.D.L.), School of Medicine and Health Sciences, University "G. d'Annunzio," Chieti, Italy
| | - P Hanagandi
- Neuroradiology (P.H.), Karolinska Institute, Stockholm, Sweden
| | - D van Westen
- Faculty of Medicine (D.v.W.), Clinical Sciences, Lund University, Sweden
| | - A F Delgado
- Department of Surgical Sciences (Alberto F.D.), Uppsala University, Uppsala, Sweden
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17
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Components of day-to-day variability of cerebral perfusion measurements - Analysis of phase contrast mapping magnetic resonance imaging measurements in healthy volunteers. PLoS One 2018; 13:e0197807. [PMID: 29879126 PMCID: PMC5991708 DOI: 10.1371/journal.pone.0197807] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 05/09/2018] [Indexed: 11/26/2022] Open
Abstract
Purpose The aim of the study was to investigate the components of day-to-day variability of repeated phase contrast mapping (PCM) magnetic resonance imaging measurements of global cerebral blood flow (gCBF). Materials and methods Two dataset were analyzed. In Dataset 1 duplicated PCM measurements of total brain flow were performed in 11 healthy young volunteers on two separate days applying a strictly standardized setup. For comparison PCM measurements obtained from a previously published study (Dataset 2) were analyzed in order to assess long-term variability in an aged population in a less strictly controlled setup. Global CBF was calculated by normalizing total brain flow to brain volume. On each day measurements of hemoglobin, caffeine and glucose were obtained. Linear mixed models were applied to estimate coefficients of variation (CV) of total (CVt), between-subject (CVb), within-subject day-to-day (CVw), and intra-session residual variability (CVr). Results In Dataset 1 CVt, CVb, CVw and CVr were estimated to be 11%, 9.4%, 4% and 4.2%, respectively, and to 8.8%, 7.2%, 2.7% and 4.3%, respectively, when adjusting for hemoglobin and plasma caffeine. In Dataset 2 CVt, CVb and CVw were estimated to be 25.4%, 19.2%, and 15.0%, respectively, and decreased to 16.6%, 8.2% and 12.5%, respectively, when adjusting for the same covariates. Discussion Our results suggest that short-term day-to-day variability of gCBF is relatively low compared to between-subject variability when studied in standardized conditions, whereas long-term variability in an aged population appears to be much larger when studied in less a standardized setup. The results further showed that from 20% to 35% of the total variability in gCBF can be attributed to the effects of hemoglobin and caffeine.
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18
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Xu F, Li W, Liu P, Hua J, Strouse JJ, Pekar JJ, Lu H, van Zijl PCM, Qin Q. Accounting for the role of hematocrit in between-subject variations of MRI-derived baseline cerebral hemodynamic parameters and functional BOLD responses. Hum Brain Mapp 2017; 39:344-353. [PMID: 29024300 DOI: 10.1002/hbm.23846] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/22/2017] [Accepted: 10/04/2017] [Indexed: 12/19/2022] Open
Abstract
Baseline hematocrit fraction (Hct) is a determinant for baseline cerebral blood flow (CBF) and between-subject variation of Hct thus causes variation in task-based BOLD fMRI signal changes. We first verified in healthy volunteers (n = 12) that Hct values can be derived reliably from venous blood T1 values by comparison with the conventional lab test. Together with CBF measured using phase-contrast MRI, this noninvasive estimation of Hct, instead of using a population-averaged Hct value, enabled more individual determination of oxygen delivery (DO2 ), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2 ). The inverse correlation of CBF and Hct explained about 80% of between-subject variation of CBF in this relatively uniform cohort of subjects, as expected based on the regulation of DO2 to maintain constant CMRO2 . Furthermore, we compared the relationships of visual task-evoked BOLD response with Hct and CBF. We showed that Hct and CBF contributed 22%-33% of variance in BOLD signal and removing the positive correlation with Hct and negative correlation with CBF allowed normalization of BOLD signal with 16%-22% lower variability. The results of this study suggest that adjustment for Hct effects is useful for studies of MRI perfusion and BOLD fMRI. Hum Brain Mapp 39:344-353, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Feng Xu
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland.,Developing Brain Research Lab, Children's National Medical Center, Washington DC, Washington
| | - Wenbo Li
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Peiying Liu
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Jun Hua
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - John J Strouse
- Division of Hematology, Department of Medicine, Duke University, Durham, North Carolina
| | - James J Pekar
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Hanzhang Lu
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Peter C M van Zijl
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Qin Qin
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
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19
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Dai W, Duan W, Alfaro FJ, Gavrieli A, Kourtelidis F, Novak V. The resting perfusion pattern associates with functional decline in type 2 diabetes. Neurobiol Aging 2017; 60:192-202. [PMID: 28992987 DOI: 10.1016/j.neurobiolaging.2017.09.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/20/2022]
Abstract
We investigated the relationships between cerebral blood flow (CBF), cognitive, and mobility decline in type 2 diabetes mellitus (T2DM) over a 2-year period. Seventy-three participants (41 T2DM and 32 controls) were evaluated using volumetric CBF with arterial spin labeling perfusion magnetic resonance imaging at baseline and at the 2-year follow-up. Regions with significant CBF differences between T2DM participants and controls at baseline were detected using voxel-wise analysis. Correlation analysis was performed to investigate the association between regional CBF and cognitive or mobility performance over the 2-year span. Compared to controls, participants with T2DM had decreased CBF in the resting-state default mode, visual, and cerebellum networks. Greater decrease in longitudinal CBF values at these regions over a 2-year span was associated with worse gait, memory and executive functions, and higher baseline insulin resistance and worse baseline cognitive performance. In T2DM, impairment of resting regional perfusion is closely related to worse cognitive and mobility performance. Insulin resistance may further contribute to regional perfusion deficit in T2DM.
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Affiliation(s)
- Weiying Dai
- Department of Computer Science, State University of New York at Binghamton, Binghamton, NY, USA.
| | - Wenna Duan
- Department of Computer Science, State University of New York at Binghamton, Binghamton, NY, USA
| | - Freddy J Alfaro
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Anna Gavrieli
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Fotini Kourtelidis
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Vera Novak
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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20
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Hart J, Novak V, Saunders C, Gremaud PA. Transcranial Doppler-Based Surrogates for Cerebral Blood Flow: A Statistical Study. PLoS One 2016; 11:e0165536. [PMID: 27880813 PMCID: PMC5120791 DOI: 10.1371/journal.pone.0165536] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 10/13/2016] [Indexed: 11/18/2022] Open
Abstract
It is commonly assumed that perfusion in a given cerebral territory can be inferred from Blood Flow Velocity (BFV) measurements in the corresponding stem artery. In order to test this hypothesis, we construct a cerebral blood flow (CBF) estimator based on transcranial Doppler (TCD) blood flow velocity and ten other easily available patient characteristics and clinical parameters. A total of 261 measurements were collected from 88 older patients. The estimator is based on local regression (Random Forest). Its performance is analyzed against baseline CBF from 3-D pseudocontinuous arterial spin labeling (pCASL) magnetic resonance imaging (MRI). Patient specific CBF predictions are of poor quality (r = 0.41 and p-value = 4.5 × 10−12); the hypothesis is thus not clearly supported by evidence.
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Affiliation(s)
- Joseph Hart
- Department of Mathematics, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Vera Novak
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - Charles Saunders
- Engineering and the Environment, University of Southampton, Southampton, United Kingdom
| | - Pierre A. Gremaud
- Department of Mathematics, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail:
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21
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Vestergaard MB, Lindberg U, Aachmann-Andersen NJ, Lisbjerg K, Christensen SJ, Rasmussen P, Olsen NV, Law I, Larsson HBW, Henriksen OM. Comparison of global cerebral blood flow measured by phase-contrast mapping MRI with 15 O-H 2 O positron emission tomography. J Magn Reson Imaging 2016; 45:692-699. [PMID: 27619317 PMCID: PMC5324556 DOI: 10.1002/jmri.25442] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 06/22/2016] [Accepted: 06/22/2016] [Indexed: 11/28/2022] Open
Abstract
Purpose To compare mean global cerebral blood flow (CBF) measured by phase‐contrast mapping magnetic resonance imaging (PCM MRI) and by 15O‐H2O positron emission tomography (PET) in healthy subjects. PCM MRI is increasingly being used to measure mean global CBF, but has not been validated in vivo against an accepted reference technique. Materials and Methods Same‐day measurements of CBF by 15O‐H2O PET and subsequently by PCM MRI were performed on 22 healthy young male volunteers. Global CBF by PET was determined by applying a one‐tissue compartment model with measurement of the arterial input function. Flow was measured in the internal carotid and vertebral arteries by a noncardiac triggered PCM MRI sequence at 3T. The measured flow was normalized to total brain weight determined from a volume‐segmented 3D T1‐weighted anatomical MR‐scan. Results Mean CBF was 34.9 ± 3.4 mL/100 g/min measured by 15O‐H2O PET and 57.0 ± 6.8 mL/100 g/min measured by PCM MRI. The measurements were highly correlated (P = 0.0008, R2 = 0.44), although values obtained by PCM MRI were higher compared to 15O‐H2O PET (absolute and relative differences were 22.0 ± 5.2 mL/100 g/min and 63.4 ± 14.8%, respectively). Conclusion This study confirms the use of PCM MRI for quantification of global CBF, but also that PCM MRI systematically yields higher values relative to 15O‐H2O PET, probably related to methodological bias. Level of Evidence: 3 J. Magn. Reson. Imaging 2017;45:692–699.
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Affiliation(s)
- Mark Bitsch Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet Glostrup, Glostrup, Denmark
| | - Ulrich Lindberg
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet Glostrup, Glostrup, Denmark
| | - Niels Jacob Aachmann-Andersen
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristian Lisbjerg
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Søren Just Christensen
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Rasmussen
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Niels Vidiendal Olsen
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Neuroanaesthesia, Neuroscience Centre, Copenhagen University Hospital Rigshospitalet Blegdamsvej, Copenhagen, Denmark
| | - Ian Law
- Institute for Clinical Medicine, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet Blegdamsvej, Copenhagen, Denmark
| | - Henrik Bo Wiberg Larsson
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet Glostrup, Glostrup, Denmark.,Institute for Clinical Medicine, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Otto Mølby Henriksen
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet Blegdamsvej, Copenhagen, Denmark
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22
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Finkelmeyer A, Nilsson J, He J, Stevens L, Maller JJ, Moss RA, Small S, Gallagher P, Coventry K, Ferrier IN, McAllister-Williams RH. Altered hippocampal function in major depression despite intact structure and resting perfusion. Psychol Med 2016; 46:2157-2168. [PMID: 27192934 DOI: 10.1017/s0033291716000702] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Hippocampal volume reductions in major depression have been frequently reported. However, evidence for functional abnormalities in the same region in depression has been less clear. We investigated hippocampal function in depression using functional magnetic resonance imaging (fMRI) and neuropsychological tasks tapping spatial memory function, with complementing measures of hippocampal volume and resting blood flow to aid interpretation. METHOD A total of 20 patients with major depressive disorder (MDD) and a matched group of 20 healthy individuals participated. Participants underwent multimodal magnetic resonance imaging (MRI): fMRI during a spatial memory task, and structural MRI and resting blood flow measurements of the hippocampal region using arterial spin labelling. An offline battery of neuropsychological tests, including several measures of spatial memory, was also completed. RESULTS The fMRI analysis showed significant group differences in bilateral anterior regions of the hippocampus. While control participants showed task-dependent differences in blood oxygen level-dependent (BOLD) signal, depressed patients did not. No group differences were detected with regard to hippocampal volume or resting blood flow. Patients showed reduced performance in several offline neuropsychological measures. All group differences were independent of differences in hippocampal volume and hippocampal blood flow. CONCLUSIONS Functional abnormalities of the hippocampus can be observed in patients with MDD even when the volume and resting perfusion in the same region appear normal. This suggests that changes in hippocampal function can be observed independently of structural abnormalities of the hippocampus in depression.
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Affiliation(s)
- A Finkelmeyer
- Institute of Neuroscience, Newcastle University,Newcastle-upon-Tyne,UK
| | - J Nilsson
- Aging Research Center, Karolinska Institute,Stockholm,Sweden
| | - J He
- Aberdeen Biomedical Imaging Centre, University of Aberdeen,Aberdeen,UK
| | - L Stevens
- Institute of Neuroscience, Newcastle University,Newcastle-upon-Tyne,UK
| | - J J Maller
- Monash Alfred Psychiatry Research Centre, Monash University,Melbourne,VIC,Australia
| | - R A Moss
- Institute of Neuroscience, Newcastle University,Newcastle-upon-Tyne,UK
| | - S Small
- Institute of Neuroscience, Newcastle University,Newcastle-upon-Tyne,UK
| | - P Gallagher
- Institute of Neuroscience, Newcastle University,Newcastle-upon-Tyne,UK
| | - K Coventry
- School of Psychology, University of East Anglia,Norwich,UK
| | - I N Ferrier
- Institute of Neuroscience, Newcastle University,Newcastle-upon-Tyne,UK
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23
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Macey PM. Altered Resting Cerebral Blood Flow in Obstructive Sleep Apnea: A Helpful Change or Not? Sleep 2015; 38:1345-7. [PMID: 26285008 DOI: 10.5665/sleep.4962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 07/29/2015] [Indexed: 11/03/2022] Open
Affiliation(s)
- Paul M Macey
- UCLA School of Nursing; Brain Research Institute, University of California at Los Angeles, Los Angeles, CA
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24
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Förster A, Al-Zghloul M, Kerl HU, Böhme J, Mürle B, Groden C. Value of dynamic susceptibility contrast perfusion MRI in the acute phase of transient global amnesia. PLoS One 2015; 10:e0122537. [PMID: 25803440 PMCID: PMC4372367 DOI: 10.1371/journal.pone.0122537] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 02/18/2015] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Transient global amnesia (TGA) is a transitory, short-lasting neurological disorder characterized by a sudden onset of antero- and retrograde amnesia. Perfusion abnormalities in TGA have been evaluated mainly by use of positron emission tomography (PET) or single-photon emission computed tomography (SPECT). In the present study we explore the value of dynamic susceptibility contrast perfusion-weighted MRI (PWI) in TGA in the acute phase. METHODS From a MRI report database we identified TGA patients who underwent MRI including PWI in the acute phase and compared these to control subjects. Quantitative perfusion maps (cerebral blood flow (CBF) and volume (CBV)) were generated and analyzed by use of Signal Processing In NMR-Software (SPIN). CBF and CBV values in subcortical brain regions were assessed by use of VOI created in FIRST, a model-based segmentation tool in the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (FSL). RESULTS Five TGA patients were included (2 men, 3 women). On PWI, no relevant perfusion alterations were found by visual inspection in TGA patients. Group comparisons for possible differences between TGA patients and control subjects showed significant lower rCBF values bilaterally in the hippocampus, in the left thalamus and globus pallidus as well as bilaterally in the putamen and the left caudate nucleus. Correspondingly, significant lower rCBV values were observed bilaterally in the hippocampus and the putamen as well as in the left caudate nucleus. Group comparisons for possible side differences in rCBF and rCBV values in TGA patients revealed a significant lower rCBV value in the left caudate nucleus. CONCLUSIONS Mere visual inspection of PWI is not sufficient for the assessment of perfusion changes in TGA in the acute phase. Group comparisons with healthy control subjects might be useful to detect subtle perfusion changes on PWI in TGA patients. However, this should be confirmed in larger data sets and serial PWI examinations.
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Affiliation(s)
- Alex Förster
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
- * E-mail:
| | - Mansour Al-Zghloul
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Hans U. Kerl
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Johannes Böhme
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Bettina Mürle
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Christoph Groden
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
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25
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Chellan P, Sadler PJ. The elements of life and medicines. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2015; 373:20140182. [PMID: 25666066 PMCID: PMC4342972 DOI: 10.1098/rsta.2014.0182] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Which elements are essential for human life? Here we make an element-by-element journey through the periodic table and attempt to assess whether elements are essential or not, and if they are, whether there is a relevant code for them in the human genome. There are many difficulties such as the human biochemistry of several so-called essential elements is not well understood, and it is not clear how we should classify elements that are involved in the destruction of invading microorganisms, or elements which are essential for microorganisms with which we live in symbiosis. In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry. Today, the biological periodic table is in a position somewhat similar to Mendeleev's chemical periodic table of 1869: there are gaps and we need to do more research to fill them. The periodic table also offers potential for novel therapeutic and diagnostic agents, based on not only essential elements, but also non-essential elements, and on radionuclides. Although the potential for inorganic chemistry in medicine was realized more than 2000 years ago, this area of research is still in its infancy. Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism. Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed.
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Affiliation(s)
- Prinessa Chellan
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Peter J Sadler
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
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26
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Rusinek H, Ha J, Yau PL, Storey P, Tirsi A, Tsui WH, Frosch O, Azova S, Convit A. Cerebral perfusion in insulin resistance and type 2 diabetes. J Cereb Blood Flow Metab 2015; 35:95-102. [PMID: 25315860 PMCID: PMC4294398 DOI: 10.1038/jcbfm.2014.173] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/19/2014] [Accepted: 09/10/2014] [Indexed: 11/09/2022]
Abstract
Cerebral perfusion was evaluated in 87 subjects prospectively enrolled in three study groups-healthy controls (HC), patients with insulin resistance (IR) but not with diabetes, and type 2 diabetes mellitus (T2DM). Participants received a comprehensive 8-hour clinical evaluation and arterial spin labeling magnetic resonance imaging (MRI). In order of decreasing significance, an association was found between cerebral blood flow (CBF) and sex, waist circumference, diastolic blood pressure (BP), end tidal CO2, and verbal fluency score (R(2)=0.27, F=5.89, P<0.001). Mean gray-matter CBF in IR was 4.4 mL/100 g per minute lower than in control subjects (P=0.005), with no hypoperfusion in T2DM (P=0.312). Subjects with IR also showed no CO2 relationship (slope=-0.012) in the normocapnic range, in contrast to a strong relationship in healthy brains (slope=0.800) and intermediate response (slope=0.445) in diabetic patients. Since the majority of T2DM but few IR subjects were aggressively treated with blood glucose, cholesterol, and BP lowering medications, our finding could be attributed to the beneficial effect of these drugs.
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Affiliation(s)
- Henry Rusinek
- Department of Radiology, NYU School of Medicine, New York, New York, USA
| | - Jenny Ha
- Department of Psychiatry, NYU School of Medicine, New York, New York, USA
| | - Po Lai Yau
- Department of Psychiatry, NYU School of Medicine, New York, New York, USA
| | - Pippa Storey
- Department of Radiology, NYU School of Medicine, New York, New York, USA
| | - Aziz Tirsi
- Department of Psychiatry, NYU School of Medicine, New York, New York, USA
| | - Wai Hon Tsui
- Department of Psychiatry, NYU School of Medicine, New York, New York, USA
| | | | | | - Antonio Convit
- 1] Department of Psychiatry, NYU School of Medicine, New York, New York, USA [2] Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
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27
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Henriksen OM, Jensen LT, Krabbe K, Guldberg P, Teerlink T, Rostrup E. Resting brain perfusion and selected vascular risk factors in healthy elderly subjects. PLoS One 2014; 9:e97363. [PMID: 24840730 PMCID: PMC4026139 DOI: 10.1371/journal.pone.0097363] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 04/18/2014] [Indexed: 11/18/2022] Open
Abstract
Background and Purpose Both cerebral hypoperfusion and vascular risk factors have been implicated in early aging of the brain and the development of neurodegenerative disease. However, the current knowledge of the importance of cardiovascular health on resting brain perfusion is limited. The aim of the present study was to elucidate the relation between brain perfusion variability and risk factors of endothelial dysfunction and atherosclerosis in healthy aged subjects. Methods Thirty-eight healthy subjects aged 50–75 years old were included. Mean global brain perfusion was measured using magnetic resonance phase contrast mapping and regional brain perfusion by use of arterial spin labeling. Results Mean global brain perfusion was inversely correlated with caffeine and hematocrit, and positively with end-tidal PCO2. Furthermore, the mean global brain perfusion was inversely correlated with circulating homocysteine, but not with asymmetric dimethylarginine, dyslipidemia or the carotid intima-media thickness. The relative regional brain perfusion was associated with circulating homocysteine, with a relative parietal hypoperfusion and a frontal hyperperfusion. No effect on regional brain perfusion was observed for any of the other risk factors. A multiple regression model including homocysteine, caffeine, hematocrit and end-tidal PCO2, explained nearly half of the observed variability. Conclusion Both intrinsic and extrinsic factors influenced global cerebral perfusion variation between subjects. Further, the results suggest that the inverse relation between homocysteine and brain perfusion is owing to other mechanisms, than reflected by asymmetric dimethylarginine, and that homocysteine may be a marker of cerebral perfusion in aging brains.
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Affiliation(s)
- Otto M. Henriksen
- Functional Imaging Unit, Section of Clinical Physiology and Nuclear Medicine, Department of Diagnostics, Glostrup Hospital, Copenhagen University Hospital, Glostrup, Denmark
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
- Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| | - Lars T. Jensen
- Department Clinical Physiology and Nuclear Medicine, Herlev Hospital, Copenhagen University Hospital, Herlev, Denmark
| | - Katja Krabbe
- Section of Radiology, Department of Diagnostics, Glostrup Hospital, Copenhagen University Hospital, Glostrup, Denmark
| | - Per Guldberg
- Institute of Cancer Biology, Danish Cancer Society, Copenhagen, Denmark
| | - Tom Teerlink
- Metabolic Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands
| | - Egill Rostrup
- Functional Imaging Unit, Section of Clinical Physiology and Nuclear Medicine, Department of Diagnostics, Glostrup Hospital, Copenhagen University Hospital, Glostrup, Denmark
- Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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28
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Henriksen OM, Jensen LT, Krabbe K, Larsson HBW, Rostrup E. Relationship between cardiac function and resting cerebral blood flow: MRI measurements in healthy elderly subjects. Clin Physiol Funct Imaging 2013; 34:471-7. [DOI: 10.1111/cpf.12119] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 11/20/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Otto M. Henriksen
- Functional Imaging Unit; Section of Clinical Physiology and Nuclear Medicine; Department of Diagnostics; Glostrup Hospital; Copenhagen University Hospital; Glostrup Denmark
- Department of Clinical Physiology; Nuclear Medicine and PET; Rigshospitalet, Copenhagen University Hospital; Copenhagen Denmark
- Center for Healthy Aging; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - Lars T. Jensen
- Department of Clinical Physiology and Nuclear Medicine; Herlev Hospital; Copenhagen University Hospital; Herlev Denmark
| | - Katja Krabbe
- Section of Radiology; Department of Diagnostics; Glostrup Hospital; Copenhagen University Hospital; Glostrup Denmark
| | - Henrik B. W. Larsson
- Functional Imaging Unit; Section of Clinical Physiology and Nuclear Medicine; Department of Diagnostics; Glostrup Hospital; Copenhagen University Hospital; Glostrup Denmark
| | - Egill Rostrup
- Functional Imaging Unit; Section of Clinical Physiology and Nuclear Medicine; Department of Diagnostics; Glostrup Hospital; Copenhagen University Hospital; Glostrup Denmark
- Center for Healthy Aging; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
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