High-resolution 7T MRI of the human hippocampus in vivo

AbstractObjectiveMinimum deformation averaging (MDA) procedures exploit the information contained in inter-individual variations to generate high-resolution, high-contrast models through iterative model building. However, MDA models built from different image contrasts reside in disparate spaces and their complementary information cannot be utilized easily. The aim of this work was to develop an algorithm for the non-linear alignment of two MDA models with different contrasts to create a high-resolution in vivo model of the human hippocampus with a spatial resolution of 300 μm.MethodsA Turbo Spin Echo MDA model covering the hippocampus was contrast matched to a whole-brain MP2RAGE MDA model and aligned using cross-correlation and non-linear transformation. The contrast matching algorithm followed a global voxel location-based approach to estimate the relationship between intensity values of the two models. The performance of the algorithm was evaluated by comparing it to a non-linear registration obtained using mutual information without contrast matching. The complimentary information from both contrasts was then utilized in an automated hippocampal subfield segmentation pipeline.ResultsThe contrast of the Turbo Spin Echo MDA model could successfully be matched to the MP2RAGE MDA model. Registration using cross correlation provided more accurate alignment of the models compared to a mutual information based approach. The segmentation using ASHS resulted in hippocampal subfield delineations that resembled the tissue boundaries observed in the Turbo Spin Echo MDA model.ConclusionThe developed contrast matching algorithm facilitated the creation of a high-resolution multi-modal in vivo MDA model of the human hippocampus. This model can be used to improve algorithms for hippocampal subfield segmentation and could potentially support the early detection of neurodegenerative diseases.

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High-Resolution 7T MR Imaging of the Human Subgenual Prefrontal Cortex in vivo- Development of a segmentation algorithm and its application in mood disorders

Klinische Neurophysiologie ◽

10.1055/s-0033-1337207 ◽

2013 ◽

Vol 44 (01) ◽

Author(s):

A Tränkner ◽

P Schönknecht

Keyword(s):

Prefrontal Cortex ◽

High Resolution ◽

Mr Imaging ◽

Mood Disorders ◽

Segmentation Algorithm

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Faculty Opinions recommendation of High-Throughput, High-Resolution Mapping of Protein Localization in Mammalian Brain by In Vivo Genome Editing.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726346764.793519161 ◽

2016 ◽

Author(s):

Vijay Tiwari ◽

Amitava Basu

Keyword(s):

High Resolution ◽

Genome Editing ◽

High Throughput ◽

Protein Localization ◽

Mammalian Brain ◽

High Resolution Mapping ◽

Resolution Mapping

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Faculty Opinions recommendation of Direct wavefront sensing for high-resolution in vivo imaging in scattering tissue.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726327470.793517748 ◽

2016 ◽

Author(s):

Paul Timpson ◽

Claire Vennin

Keyword(s):

High Resolution ◽

In Vivo Imaging ◽

Wavefront Sensing

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Optimization of spectral-domain optical coherence tomography with a supercontinuum source for in vivo motion detection of low reflective outer hair cells in guinea pig cochleae

Optical Review ◽

10.1007/s10043-021-00654-8 ◽

2021 ◽

Author(s):

Fumiaki Nin ◽

Samuel Choi ◽

Takeru Ota ◽

Zhang Qi ◽

Hiroshi Hibino

Keyword(s):

Optical Coherence Tomography ◽

High Resolution ◽

Guinea Pig ◽

Hair Cells ◽

Sensory Epithelium ◽

Outer Hair Cells ◽

Acquisition Time ◽

Total Acquisition Time ◽

Sd Oct

AbstractSound evokes sub-nanoscale vibration within the sensory epithelium. The epithelium contains not only immotile cells but also contractile outer hair cells (OHCs) that actively shrink and elongate synchronously with the sound. However, the in vivo motion of OHCs has remained undetermined. The aim of this work is to perform high-resolution and -accuracy vibrometry in live guinea pigs with an SC-introduced spectral-domain optical coherence tomography system (SD-OCT). In this study, to reveal the effective contribution of SC source in the recording of the low reflective materials with the short total acquisition time, we compare the performances of the SC-introduced SD-OCT (SCSD-OCT) to that of the conventional SD-OCT. As inanimate comparison objects, we record a mirror, a piezo actuator, and glass windows. For the measurements in biological materials, we use in/ex vivo guinea pig cochleae. Our study achieved the optimization of a SD-OCT system for high-resolution in vivo vibrometry in the cochlear sensory epithelium, termed the organ of Corti, in mammalian cochlea. By introducing a supercontinuum (SC) light source and reducing the total acquisition time, we improve the axial resolution and overcome the difficulty in recording the low reflective material in the presence of biological noise. The high power of the SC source enables the system to achieve a spatial resolution of 1.72 ± 0.00 μm on a mirror and reducing the total acquisition time contributes to the high spatial accuracy of sub-nanoscale vibrometry. Our findings reveal the vibrations at the apical/basal region of OHCs and the extracellular matrix, basilar membrane.

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Iron accumulation in the oculomotor nerve of the progressive supranuclear palsy brain

Scientific Reports ◽

10.1038/s41598-021-82469-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hansol Lee ◽

Myung Jun Lee ◽

Eun-Joo Kim ◽

Gi Yeong Huh ◽

Jae-Hyeok Lee ◽

...

Keyword(s):

High Resolution ◽

Progressive Supranuclear Palsy ◽

Oculomotor Nerve ◽

Iron Accumulation ◽

Blue Staining ◽

Normal Brain ◽

Myelinated Fiber ◽

Healthy Controls ◽

Icp Ms

AbstractAbnormal iron accumulation around the substantia nigra (SN) is a diagnostic indicator of Parkinsonism. This study aimed to identify iron-related microarchitectural changes around the SN of brains with progressive supranuclear palsy (PSP) via postmortem validations and in vivo magnetic resonance imaging (MRI). 7 T high-resolution MRI was applied to two postmortem brain tissues, from one normal brain and one PSP brain. Histopathological examinations were performed to demonstrate the molecular origin of the high-resolution postmortem MRI findings, by using ferric iron staining, myelin staining, and two-dimensional laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging. In vivo iron-related MRI was performed on five healthy controls, five patients with Parkinson’s disease (PD), and five patients with PSP. In the postmortem examination, excessive iron deposition along the myelinated fiber at the anterior SN and third cranial nerve (oculomotor nerve) fascicles of the PSP brain was verified by LA-ICP-MS. This region corresponded to those with high R2* values and positive susceptibility from quantitative susceptibility mapping (QSM), but was less sensitive in Perls’ Prussian blue staining. In in vivo susceptibility-weighted imaging, hypointense pixels were observed in the region between the SN and red nucleus (RN) in patients with PSP, but not in healthy controls and patients with PD. R2* and QSM values of such region were significantly higher in patients with PSP compared to those in healthy controls and patients with PD as well (vs. healthy control: p = 0.008; vs. PD: p = 0.008). Thus, excessive iron accumulation along the myelinated fibers at the anterior SN and oculomotor nerve fascicles may be a pathological characteristic and crucial MR biomarker in a brain with PSP.

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High-resolution in vivo imaging of rhesus cerebral cortex with ultrafast portable photoacoustic microscopy

NeuroImage ◽

10.1016/j.neuroimage.2021.118260 ◽

2021 ◽

pp. 118260

Author(s):

Wei Qin ◽

Qi Gan ◽

Lei Yang ◽

Yongchao Wang ◽

Weizhi Qi ◽

...

Keyword(s):

Cerebral Cortex ◽

High Resolution ◽

In Vivo Imaging ◽

Photoacoustic Microscopy

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Polymorphisms in Plasmodium falciparum dihydropteroate synthetase and dihydrofolate reductase genes in Nigerian children with uncomplicated malaria using high-resolution melting technique

Scientific Reports ◽

10.1038/s41598-020-80017-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Adeyemi T. Kayode ◽

Fehintola V. Ajogbasile ◽

Kazeem Akano ◽

Jessica N. Uwanibe ◽

Paul E. Oluniyi ◽

...

Keyword(s):

High Resolution ◽

Dihydrofolate Reductase ◽

Uncomplicated Malaria ◽

High Resolution Melting ◽

Intermittent Preventive Treatment ◽

Preventive Treatment ◽

Triple Mutant ◽

Seasonal Malaria Chemoprevention

AbstractIn 2005, the Nigerian Federal Ministry of Health revised the treatment policy for uncomplicated malaria with the introduction of artemisinin-based combination therapies (ACTs). This policy change discouraged the use of Sulphadoxine-pyrimethamine (SP) as the second-line treatment of uncomplicated falciparum malaria. However, SP is used as an intermittent preventive treatment of malaria in pregnancy (IPTp) and seasonal malaria chemoprevention (SMC) in children aged 3–59 months. There have been increasing reports of SP resistance especially in the non-pregnant population in Nigeria, thus, the need to continually monitor the efficacy of SP as IPTp and SMC by estimating polymorphisms in dihydropteroate synthetase (dhps) and dihydrofolate reductase (dhfr) genes associated with SP resistance. The high resolution-melting (HRM) assay was used to investigate polymorphisms in codons 51, 59, 108 and 164 of the dhfr gene and codons 437, 540, 581 and 613 of the dhps gene. DNA was extracted from 271 dried bloodspot filter paper samples obtained from children (< 5 years old) with uncomplicated malaria. The dhfr triple mutant I51R59N108, dhps double mutant G437G581 and quadruple dhfr I51R59N108 + dhps G437 mutant haplotypes were observed in 80.8%, 13.7% and 52.8% parasites, respectively. Although the quintuple dhfr I51R59N108 + dhps G437E540 and sextuple dhfr I51R59N108 + dhps G437E540G581 mutant haplotypes linked with in-vivo and in-vitro SP resistance were not detected, constant surveillance of these haplotypes should be done in the country to detect any change in prevalence.

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