Gradient‐echo and spin‐echo blood oxygenation level–dependent functional MRI at ultrahigh fields of 9.4 and 15.2 Tesla

Han, Sang-In; Son, Jeong Pyo; Cho, HyungJoon; Park, Jang‐Yeon; Kim, Seong‐Gi

doi:10.1002/mrm.27457

Cited by 27 publications

(27 citation statements)

References 52 publications

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“…Furthermore, GE-EPI is highly sensitive to large veins (Uludag et al, 2009), which makes this sequence spatially nonspecific as neurovascular coupling occurs at the level of the capillaries. This has been clearly demonstrated by fMRI studies in rats subjected to electrical stimulation of the forepaws, where the highest GE-EPI BOLD response is observed in the outer layer of the somatosensory cortex where pial vessels are located (Mandeville and Marota, 1999;Han et al, 2019), while neuronal activation mostly occurs in deeper cortical layers. The relative contribution of capillaries to the BOLD signal increases with field FIGURE 5 | Data acquisition.…”

Section: Data Acquisitionmentioning

confidence: 80%

“…GE-EPI provides a relatively high contrastto-noise ratio (CNR), which increases with field strength. At field strengths ≥ 7T, the intravascular contribution to the GE BOLD signal is negligible and signal changes scale almost linearly with echo time (TE) (Yacoub et al, 2003;Han et al, 2019). For optimal BOLD CNR, TE is typically set equal to the average gray matter tissue T2 * value (for an overview of brain tissue T2 and T2 * values we refer to Uludag et al (2009) and Han et al (2019).…”

Section: Data Acquisitionmentioning

confidence: 99%

“…At field strengths ≥ 7T, the intravascular contribution to the GE BOLD signal is negligible and signal changes scale almost linearly with echo time (TE) (Yacoub et al, 2003;Han et al, 2019). For optimal BOLD CNR, TE is typically set equal to the average gray matter tissue T2 * value (for an overview of brain tissue T2 and T2 * values we refer to Uludag et al (2009) and Han et al (2019). The disadvantage of using GE-EPI for rodent fMRI, however, is its sensitivity to susceptibility artifacts, which are most prominent near air cavities such as the ear canals and around the olfactory bulb, particularly at long TE and high field strength.…”

Section: Data Acquisitionmentioning

confidence: 99%

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Animal Functional Magnetic Resonance Imaging: Trends and Path Toward Standardization

Mandino

Cerri

Garin

et al. 2020

Front. Neuroinform.

100

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Animal whole-brain functional magnetic resonance imaging (fMRI) provides a noninvasive window into brain activity. A collection of associated methods aims to replicate observations made in humans and to identify the mechanisms underlying the distributed neuronal activity in the healthy and disordered brain. Animal fMRI studies have developed rapidly over the past years, fueled by the development of resting-state fMRI connectivity and genetically encoded neuromodulatory tools. Yet, comparisons between sites remain hampered by lack of standardization. Recently, we highlighted that mouse resting-state functional connectivity converges across centers, although large discrepancies in sensitivity and specificity remained. Here, we explore past and present trends within the animal fMRI community and highlight critical aspects in study design, data acquisition, and post-processing operations, that may affect the results and influence the comparability between studies. We also suggest practices aimed to promote the adoption of standards within the community and improve betweenlab reproducibility. The implementation of standardized animal neuroimaging protocols will facilitate animal population imaging efforts as well as meta-analysis and replication studies, the gold standards in evidence-based science.

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Section: Data Acquisitionmentioning

confidence: 80%

Section: Data Acquisitionmentioning

confidence: 99%

Section: Data Acquisitionmentioning

confidence: 99%

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Animal Functional Magnetic Resonance Imaging: Trends and Path Toward Standardization

Mandino

Cerri

Garin

et al. 2020

Front. Neuroinform.

100

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“…Since higher magnetic field can enhance BOLD signals 54,55 , ultra-high field MRI has been used in some studies 39,56 . We used Spin Echo-Echo Planar Imaging (SE-EPI) sequence for high-resolution fMRI at ultra-high magnetic fields 55,57 . A custom-made surface coil for 14 T-MRI was attached to the operant learning device on top, and the coil centre was fitted to the mouse bregma.…”

Section: Discussionmentioning

confidence: 99%

Hyper BOLD Activation in Dorsal Raphe Nucleus of APP/PS1 Alzheimer’s Disease Mouse during Reward-Oriented Drinking Test under Thirsty Conditions

Sakurai

Shintani

Jomura

et al. 2020

Sci Rep

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Alzheimer's disease (AD), a neurodegenerative disease, causes behavioural abnormalities such as disinhibition, impulsivity, and hyperphagia. preclinical studies using AD model mice have investigated these phenotypes by measuring brain activity in awake, behaving mice. in this study, we monitored the behavioural alterations of impulsivity and hyperphagia in middle-aged AD model mice. As a behavioural readout, we trained the mice to accept a water-reward under thirsty conditions. to analyse brain activity, we developed a measure for licking behaviour combined with visualisation of whole brain activity using awake fMRI. In a water-reward learning task, the AD model mice showed significant hyperactivity of the dorsal raphe nucleus in thirsty conditions. in summary, we successfully visualised altered brain activity in AD model mice during reward-oriented behaviour for the first time using awake fMRi. this may help in understanding the causes of behavioural alterations in AD patients.Fifty million people worldwide currently suffer from dementia. This number is estimated to reach 130 million by 2050. Alzheimer's disease (AD) is a neurodegenerative disease accounting for 60-70% of dementia cases 1 . AD develops through amnestic mild cognitive impairment (MCI), in which a decrease of memory function is the only symptom can be recognised. Once dementia develops, memory and various cognitive functions decrease, behavioural and psychological symptoms of dementia (BPSP) are also exhibited 1-3 . As these symptoms progress, it becomes impossible to maintain an independent daily life. Dementia patients mostly need medical care due to BPSP rather than reducing of memory and cognitive functions. BPSP includes depression, anxiety, and apathy. Although research on these BPSP symptoms has progressed, however, most symptoms such as disinhibition, impulsivity and hyperphagia have not been analysed in the way of pathology.AD significantly impairs reward-based behaviour (by 15-20%) in patients. A typical example is hyperphagia, which stems from a lack of satiety control, similar to disorders of impulsivity and compulsivity 4,5 . The Urgency, lack of Perseverance, lack of Premeditation, Sensation Seeking (UPPS) Scale or Barrat's Impulsiveness Scale (BIS) are now used to test for impulsivity in AD patients 3 . Overeating and impulsivity have also recently been reported in AD model mice 6,7 . These observations suggest that AD mice models may be useful in studying hyperphagia and early changes in impulsive behaviour. It has also been suggested that the brainstem serotonergic system, including the dorsal raphe nucleus 8,9 and ventral temporal lobe (hippocampus, parahippocampus, amygdala), are involved in such alterations. However, the neurological mechanisms behind these phenotypes have not yet been identified. In order to elucidate these mechanistic underpinnings, direct evaluation of brain activity associated with abnormal behaviour phenotypes is required 10 .Functional magnetic resonance imaging (fMRI) is widely used in neuroscience resea...

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“…At ultrahigh magnetic field strengths (e.g., 7T), SE-fMRI has also been shown to provide improved spatial specificity when compared with GE-fMRI, as it enhances the relative sensitivity of the BOLD signal from the parenchyma. [12][13][14] Thus, SE-fMRI with enhanced spatial specificity can be useful to study brain organization and function at the cortical laminar or columnar levels. [15][16][17][18][19][20] However, high spatiotemporal resolution SE-fMRI is difficult due to the long echo time (TE) needed to generate BOLD contrast (TE ≈ T 2 of gray matter) 13,21 and associated long repetition times (TRs), along with higher specific absorption rate (SAR) from high flipangle pulses.…”

Section: Introductionmentioning

confidence: 99%

Accelerated spin‐echo functional MRI using multisection excitation by simultaneous spin‐echo interleaving (MESSI) with complex‐encoded generalized slice dithered enhanced resolution (cgSlider) simultaneous multislice echo‐planar imaging

Han

Liao

Manhard

et al. 2019

Magnetic Resonance in Med

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Purpose Spin‐echo functional MRI (SE‐fMRI) has the potential to improve spatial specificity when compared with gradient‐echo fMRI. However, high spatiotemporal resolution SE‐fMRI with large slice‐coverage is challenging as SE‐fMRI requires a long echo time to generate blood oxygenation level‐dependent (BOLD) contrast, leading to long repetition times. The aim of this work is to develop an acquisition method that enhances the slice‐coverage of SE‐fMRI at high spatiotemporal resolution. Theory and Methods An acquisition scheme was developed entitled multisection excitation by simultaneous spin‐echo interleaving (MESSI) with complex‐encoded generalized slice dithered enhanced resolution (cgSlider). MESSI uses the dead‐time during the long echo time by interleaving the excitation and readout of 2 slices to enable 2× slice‐acceleration, while cgSlider uses the stable temporal background phase in SE‐fMRI to encode/decode 2 adjacent slices simultaneously with a “phase‐constrained” reconstruction method. The proposed cgSlider‐MESSI was also combined with simultaneous multislice (SMS) to achieve further slice‐acceleration. This combined approach was used to achieve 1.5‐mm isotropic whole‐brain SE‐fMRI with a temporal resolution of 1.5 s and was evaluated using sensory stimulation and breath‐hold tasks at 3T. Results Compared with conventional SE‐SMS, cgSlider‐MESSI‐SMS provides 4‐fold increase in slice‐coverage for the same repetition time, with comparable temporal signal‐to‐noise ratio. Corresponding fMRI activation from cgSlider‐MESSI‐SMS for both fMRI tasks were consistent with those from conventional SE‐SMS. Overall, cgSlider‐MESSI‐SMS achieved a 32× encoding‐acceleration by combining Rinplane × MB × cgSlider × MESSI = 4 × 2 × 2 × 2. Conclusion High‐quality, high‐resolution whole‐brain SE‐fMRI was acquired at a short repetition time using cgSlider‐MESSI‐SMS. This method should be beneficial for high spatiotemporal resolution SE‐fMRI studies requiring whole‐brain coverage.

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Gradient‐echo and spin‐echo blood oxygenation level–dependent functional MRI at ultrahigh fields of 9.4 and 15.2 Tesla

Abstract: SE-BOLD fMRI improves spatial specificity to microvessels compared to GE-BOLD at both fields. BOLD sensitivity is similar at the both fields and can be improved at ultrahigh fields only for thermal-noise-dominant ultrahigh-resolution fMRI.

Cited by 27 publications

References 52 publications

Animal Functional Magnetic Resonance Imaging: Trends and Path Toward Standardization

Animal Functional Magnetic Resonance Imaging: Trends and Path Toward Standardization

Hyper BOLD Activation in Dorsal Raphe Nucleus of APP/PS1 Alzheimer’s Disease Mouse during Reward-Oriented Drinking Test under Thirsty Conditions

Accelerated spin‐echo functional MRI using multisection excitation by simultaneous spin‐echo interleaving (MESSI) with complex‐encoded generalized slice dithered enhanced resolution (cgSlider) simultaneous multislice echo‐planar imaging

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