Reliability and Reproducibility of Hadamard Encoded Pseudo-Continuous Arterial Spin Labeling in Healthy Elderly

The perfusion parameters cerebral blood flow (CBF) and arterial transit time (ATT) measured with arterial spin labeling (ASL) magnetic resonance imaging (MRI) provide valuable essentials to assess the integrity of cerebral tissue. Brain perfusion changes, due to aging, an intervention, or neurodegenerative diseases for example, could be investigated in longitudinal ASL studies with reliable ASL sequences. Generally, pseudo-continuous ASL (pCASL) is preferred because of its larger signal-to-noise ratio (SNR) compared to pulsed ASL (PASL) techniques. Available pCASL versions differ regarding their feature details. To date only little is known about the reliability and reproducibility of CBF and ATT measures obtained with the innovative Hadamard encoded pCASL variant, especially if applied on participants in old age. Therefore, we investigated an in-house developed Hadamard encoded pCASL sequence on a group of healthy elderly at two different 3 Tesla Siemens MRI systems (Skyra and mMR Biograph) and evaluated CBF and ATT reliability and reproducibility for several regions-of-interests (ROI). Calculated within-subject coefficients of variation (wsCV) demonstrated an excellent reliability of perfusion measures, whereas ATT appeared to be even more reliable than CBF [e.g., wsCV(CBF) = 2.9% vs. wsCV(ATT) = 2.3% for a gray matter (GM) ROI on Skyra system]. Additionally, a substantial agreement of perfusion values acquired on both MRI systems with an inter-session interval of 78 ± 17.6 days was shown by high corresponding intra-class correlation (ICC) coefficients [e.g., ICC(CBF) = 0.704 and ICC(ATT) = 0.754 for a GM ROI]. The usability of this novel Hadamard encoded pCASL sequence might improve future follow-up perfusion studies of the aging and/or diseased brain.

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Three-dimensional whole-brain perfusion quantification using pseudo-continuous arterial spin labeling MRI at multiple post-labeling delays: accounting for both arterial transit time and impulse response function

NMR in Biomedicine ◽

10.1002/nbm.3040 ◽

2013 ◽

Vol 27 (2) ◽

pp. 116-128 ◽

Cited By ~ 18

Author(s):

Qin Qin ◽

Alan J. Huang ◽

Jun Hua ◽

John E. Desmond ◽

Robert D. Stevens ◽

...

Keyword(s):

Impulse Response ◽

Response Function ◽

Arterial Spin Labeling ◽

Three Dimensional ◽

Impulse Response Function ◽

Brain Perfusion ◽

Spin Labeling ◽

Arterial Transit Time ◽

Perfusion Quantification ◽

Continuous Arterial Spin Labeling

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Cortical microinfarcts in memory clinic patients are associated with reduced cerebral perfusion

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x19877403 ◽

2019 ◽

Vol 40 (9) ◽

pp. 1869-1878 ◽

Cited By ~ 5

Author(s):

Doeschka A Ferro ◽

Henri JJM Mutsaerts ◽

Saima Hilal ◽

Hugo J Kuijf ◽

Esben T Petersen ◽

...

Keyword(s):

Arterial Spin Labeling ◽

Cerebral Perfusion ◽

Region Of Interest ◽

Resonance Imaging ◽

Memory Clinic ◽

Anterior Circulation ◽

Cortical Gray Matter ◽

Arterial Transit Time ◽

Magnetic Resonance Imaging Mri ◽

Continuous Arterial Spin Labeling

Cerebral cortical microinfarcts (CMIs) are small ischemic lesions associated with cognitive impairment and dementia. CMIs are frequently observed in cortical watershed areas suggesting that hypoperfusion contributes to their development. We investigated if presence of CMIs was related to a decrease in cerebral perfusion, globally or specifically in cortex surrounding CMIs. In 181 memory clinic patients (mean age 72 ± 9 years, 51% male), CMI presence was rated on 3-T magnetic resonance imaging (MRI). Cerebral perfusion was assessed from cortical gray matter of the anterior circulation using pseudo-continuous arterial spin labeling parameters cerebral blood flow (CBF) (perfusion in mL blood/100 g tissue/min) and spatial coefficient of variation (CoV) (reflecting arterial transit time (ATT)). Patients with CMIs had a 12% lower CBF (beta = −.20) and 22% higher spatial CoV (beta = .20) (both p < .05) without a specific regional pattern on voxel-based CBF analysis. CBF in a 2 cm region-of-interest around the CMIs did not differ from CBF in a reference zone in the contralateral hemisphere. These findings show that CMIs in memory clinic patients are primarily related to global reductions in cerebral perfusion, thus shedding new light on the etiology of vascular brain injury in dementia.

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Mapping Brain Function Using a 30-Day Interval between Baseline and Activation: A Novel Arterial Spin Labeling fMRI Approach

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2010.89 ◽

2010 ◽

Vol 30 (10) ◽

pp. 1721-1733 ◽

Cited By ~ 14

Author(s):

Ajna Borogovac ◽

Christian Habeck ◽

Scott A Small ◽

Iris Asllani

Keyword(s):

Brain Function ◽

Arterial Spin Labeling ◽

Signal To Noise Ratio ◽

Spin Labeling ◽

Flow Density ◽

Functional Changes ◽

Young Subjects ◽

Arterial Transit Time ◽

Acute Changes

By comparing hemodynamic signals acquired immediately before and during activation, functional magnetic resonance imaging (fMRI) is well suited for mapping acute changes in brain function. However, it remains unclear whether fMRI can map functional changes over longer periods. Here, we address this issue by empirically testing the feasibility of arterial spin labeling (ASL) fMRI to detect changes in cerebral blood flow (CBF) with baseline and task separated by 1 month. To increase the sensitivity of the method, we applied an algorithm that yielded flow density (CBFd) images that were independent of tissue content. To increase the accuracy, we developed a technique that generated arterial transit time at each voxel, independently. Results showed that activation changes in CBFd during the same session were statistically the same as across 30 days. The activation CBFd on day-30 was 34% (motor) and 25% (visual) higher than the respective baselines of 83 and 107 mL/100 g/min obtained on day-1. Furthermore, the signal-to-noise ratio of the CBFd measurement was 2.1 and 2.9 times higher than that of the conventional CBF for within-subject and across-subjects comparisons, respectively ( n=9 healthy young subjects). Taken together, these results indicate that CBFd measure could be better suited than net CBF to map long-term changes in brain function.

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