scholarly journals Evaluation of the whole auditory pathway using high-resolution and functional MRI at 7T parallel-transmit

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0254378
Author(s):  
Sandra Da Costa ◽  
Jérémie Clément ◽  
Rolf Gruetter ◽  
Özlem Ipek
Keyword(s):  
High Resolution ◽  
Inner Ear ◽  
Functional Mri ◽  
Qualitative Evaluation ◽  
Auditory Pathway ◽  
Rf Coil ◽  
Parallel Transmit ◽  
Cross Correlation Analysis ◽  
Left And Right ◽  
Auditory Functions

Purpose The aim of the present study is to show a MR procedure for the evaluation of simultaneous left and right auditory functions with functional MRI, and high-resolution acquisition of anatomical auditory pathway using parallel-transmit (pTx) methods at 7T. Methods The time-efficient MR acquisition included two steps: RF weights were optimized for the regions-of-interest and high-resolution MR images of the inner-ear were acquired for the first 30 min (400 μm-iso resolution) followed by functional MRI acquisitions along the whole auditory pathway during the next 20 minutes. Data was processed with a linear cross-correlation analysis to define frequency preferences for each voxel in the auditory relays. Results Tonotopic maps revealed ordered bilateral frequency gradients in the auditory relays whereas at the level of the cochlear nuclei and superior olivary complexes the frequency gradients were less evident. A 21% increase in transmit-field efficiency was achieved over the left/right inner-ear regions and thus its main structures were clearly discernible using the pTx methods, compared to a single transmit RF coil. Conclusion Using 7T pTx allows a fast (less than 60 min in total) and qualitative evaluation of the simultaneous left and right auditory response along the entire auditory pathway, together with high-resolution anatomical images of the inner-ear. This could be further used for patient examination at 7T.

scholarly journals High-resolution uniform MR imaging of finger joints using a dedicated RF coil at 3T

2009 ◽  
Vol 31 (1) ◽  
pp. 240-247 ◽  
Author(s):  
Wingchi E. Kwok ◽  
Zhigang You ◽  
Johnny Monu ◽  
Gwysuk Seo ◽  
Christopher Ritchlin
Keyword(s):  
High Resolution ◽  
Mr Imaging ◽  
Rf Coil ◽  
Finger Joints

scholarly journals Facial nerve anomalies in paediatric cochlear implant candidates: radiological evaluation

2016 ◽  
Vol 131 (1) ◽  
pp. 26-31 ◽  
Author(s):  
F B Palabiyik ◽  
K Hacikurt ◽  
Z Yazici
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Facial Nerve ◽  
Cochlear Implant ◽  
Inner Ear ◽  
Resonance Imaging ◽  
High Resolution Computed Tomography ◽  
Ear Anomalies

AbstractBackground:Pre-operative radiological identification of facial nerve anomalies can help prevent intra-operative facial nerve injury during cochlear implantation. This study aimed to evaluate the incidence and configuration of facial nerve anomalies and their concurrence with inner-ear anomalies in cochlear implant candidates.Methods:Inner-ear and concomitant facial nerve anomalies were evaluated by magnetic resonance imaging and temporal high-resolution computed tomography in 48 children with congenital sensorineural hearing loss who were cochlear implant candidates.Results:Inner-ear anomalies were present in 11 out of 48 patients (23 per cent) and concomitant facial nerve anomalies were present on 7 sides in 4 patients (7 per cent of the total). Facial nerve anomalies were accompanied by cochlear or vestibular malformation.Conclusion:Potential facial nerve abnormalities should always be considered in patients with inner-ear anomalies. Pre-operative facial nerve imaging can increase the surgeon's confidence to plan and perform cochlear implantation. Magnetic resonance imaging should be used to detect inner-ear anomalies; if these are identified, temporal high-resolution computed tomography should be used to evaluate the facial nerve.

HIGH-RESOLUTION MR IMAGING OF THE AUDITORY PATHWAY

1998 ◽  
Vol 6 (1) ◽  
pp. 195-217
Author(s):  
Jeffrey A. Stone ◽  
Donald W. Chakeres ◽  
Petra Schmalbrock
Keyword(s):  
High Resolution ◽  
Mr Imaging ◽  
Auditory Pathway

scholarly journals Hippocampal morphometry in sudden and unexpected death in epilepsy

Neurology ◽  
2019 ◽  
Vol 93 (8) ◽  
pp. e804-e814 ◽  
Author(s):  
Alyma Somani ◽  
Anita-Beatrix Zborovschi ◽  
Yan Liu ◽  
Smriti Patodia ◽  
Zuzanna Michalak ◽  
...  
Keyword(s):  
Granule Cell ◽  
Hippocampal Sclerosis ◽  
Qualitative Evaluation ◽  
Granule Cell Layer ◽  
Parahippocampal Gyrus ◽  
Unexpected Death ◽  
Cell Dispersion ◽  
Autonomic Networks ◽  
Left And Right ◽  
The Right

ObjectiveTo determine hippocampal morphometric measures, including granule cell dispersion and features of malrotation, as potential biomarkers for sudden unexpected death in epilepsy (SUDEP) from an archival postmortem series.MethodsIn a retrospective study of 187 archival postmortems from 3 groups, SUDEP (68; 14 with hippocampal sclerosis [HS]), non-SUDEP epilepsy controls (EP-C = 66; 25 with HS), and nonepilepsy controls (NEC = 53), Nissl/hematoxylin & eosin–stained sections from left and right hippocampus from 5 coronal levels were digitized. Image analysis was carried out for granule cell layer (GCL) thickness and measurements of hippocampal dimensions (HD) for shape (width [HD1], height [HD2]) and medial hippocampal positioning in relation to the parahippocampal gyrus (PHG) length (HD3). A qualitative evaluation of hippocampal malrotational (HMAL) features, dentate gyrus invaginations (DGI), and subicular/CA1 folds (SCF) was also made.ResultsGCL thickness was increased in HS more than those without (p < 0.001). In non-HS cases, increased GCL thickness was noted in EP-C compared to NEC (p < 0.05) but not between SUDEP and NEC. There was no difference in the frequency of DGI, SCF, measurements of hippocampal shape (HD1, HD2, or ratio), or medial positioning among SUDEP, EP-C, and NEC groups, when factoring in HS, coronal level, and age at death. Comparison between left and right sides within cases showed greater PHG lengths (HD3) on the right side in the SUDEP group only (p = 0.018).ConclusionsNo hippocampal morphometric features were identified in support of either excessive granule cell dispersion or features of HMAL as definitive biomarkers for SUDEP. Asymmetries in PHG measurements in SUDEP warrant further investigation as they may indicate abnormal central autonomic networks.

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