Abstract W P45: High Resolution Images of Perforating Arteries With 7T MRA in Acute Subcortical Infarction

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Hideki Ohba ◽  
Taisuke Harada ◽  
Makoto Sasaki ◽  
Kazumasa Ohura ◽  
Tatsunori Natori ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
Infarct Volume ◽  
7 Tesla ◽  
Ischemic Lesion ◽  
Clinical Prognosis ◽  
Tof Mra ◽  
Perforating Artery ◽  
Subcortical Infarction ◽  
Perforating Arteries

Introduction: Patients with acute subcortical infarction show various clinical courses according to the pathology of perforating artery so that the noninvasive and precise neuroradiological evaluation of these arteries is very important for prevention of progression and recurrence of the disease. 7 Tesla (7T) - MRI (Magnetic Resonance Imaging) makes it possible to visualize perforating arteries in a way that would not otherwise be possible using conventional MRI. We attempted to assess perforating arteries and infarct lesions in the lenticulostriate artery (LSA) area using 7T- High resolution MRA (Magnetic Resonance Angiography), and to evaluate the association between image findings and clinical courses of treatment. Method: We included 13 patients (M:F = 7:6, mean age: 65 years old) with acute noncardioembolic stroke in LSA area detected by 1.5-T MRI. 7T MRI was acquired among these patients within 2 weeks after onset to visualize responsible LSA and to measure the volume of infarction by 7T-MRI- 3D-TOF MRA, 3D-FLAIR. We also evaluated the association between these results and the severity of stroke by National Institute of Health Stroke Scale (NIHSS). Results: Perforating arteries in the basal ganglia area were clearly visualized in all patients using 7T MRA. According to the location of occlusion and ischemic lesion, patients were categorized into 3 groups (A, B, and C): Group A - patients with proximal branch occlusion of LSA (2 cases), Group B - patients with occlusion of LSA adjacent to the ischemic lesion (7 cases), Group C - no occlusions (4 cases) in LSA associated with infarction. Significant association between overall infarct volume and NIHSS(r=0.636, p=0.020)was observed, whereas infarct volume of each group was not associated with NIHSS. Clinical outcome were not associated with volume of infarction in all cases(p=0.12). However, there were no patients whose symptoms progressed in Group C. Conclusion: 7 T-MRA can provide a clear visualization of perforating arteries and occluded lesions. It can be a useful and noninvasive diagnostic tool to study clinical prognosis after treatment in acute subcortical infarction.

PD54-08 EX-VIVO EXPERIMENTAL 7 TESLA HIGH RESOLUTION MAGNETIC RESONANCE IMAGING - OF LOCALIZED PROSTATE CANCER

2020 ◽  
Vol 203 ◽  
pp. e1106-e1107
Author(s):  
Matthieu Durand* ◽  
Thomas Bessede ◽  
Patrick-Julien Treacy ◽  
Imad Bentellis ◽  
Idoia Corcuera-Solano ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Prostate Cancer ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Ex Vivo ◽  
Localized Prostate Cancer ◽  
7 Tesla ◽  
Resonance Imaging

scholarly journals Ex-vivo experimental 7 Tesla high resolution magnetic resonance imaging of localized prostate cancer

2020 ◽  
Vol 19 ◽  
pp. e585-e586
Author(s):  
M. Durand ◽  
T. Bessede ◽  
P-J. Treacy ◽  
I. Bentellis ◽  
I. Corcuera-Solano ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Prostate Cancer ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Ex Vivo ◽  
Localized Prostate Cancer ◽  
7 Tesla ◽  
Resonance Imaging

scholarly journals Lipid suppressed and tissue-fraction corrected metabolic distributions in human central brain structures using 2D 1H Magnetic Resonance Spectroscopic Imaging at 7 tesla

2020 ◽  
Author(s):  
Alex A. Bhogal ◽  
Tommy A.A. Broeders ◽  
Lisan Morsinkhof ◽  
Mirte Edens ◽  
Sahar Nassirpour ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
Spectroscopic Imaging ◽  
Magnetic Resonance Spectroscopic Imaging ◽  
Brain Diseases ◽  
7 Tesla ◽  
Partial Volume ◽  
Scan Time ◽  
Central Brain

ABSTRACTMagnetic resonance spectroscopic imaging (MRSI) has the potential to add a layer of understanding of the neurobiological mechanisms underlying brain diseases, disease progression, and treatment efficacy. Limitations related to metabolite fitting of low SNR data, signal variations due to partial volume effects, acquisition and extra-cranial lipid artefacts, along with clinically relevant aspects such as scan-time constraints, are among the factors that hinder the widespread implementation of in vivo MRSI. The aim of this work was to address these factors and to develop an acquisition, reconstruction and post-processing pipeline to derive lipid suppressed metabolite values based on Free Induction Decay (FID-MRSI) measurements made using a 7 tesla MR scanner. Anatomical images were used to perform high-resolution (1mm3) partial-volume correction to account for grey matter, white matter and cerebral-spinal fluid signal contributions. Implementation of automatic quality control thresholds and normalization of metabolic maps from 23 subjects to the MNI standard atlas facilitated the creation of high-resolution average metabolite maps of several clinically relevant metabolites in central brain regions, while accounting for macromolecular distributions. Reported metabolite values include glutamate, choline, (phospo)creatine, myo-inositol, glutathione, N-acetyl aspartyl glutamate(and glutamine) and N-acetyl aspartate. MNI-registered average metabolite maps facilitate group-based analysis; thus offering the possibility to mitigate uncertainty in variable MRSI.

scholarly journals Endoscopic Endonasal Transclival Approach to the Ventral Brainstem: Anatomic Study of the Safe Entry Zones Combining Fiber Dissection Technique with 7 Tesla Magnetic Resonance Guided Neuronavigation

2018 ◽  
Vol 16 (2) ◽  
pp. 239-249 ◽  
Author(s):  
Alessandro Weiss ◽  
Paolo Perrini ◽  
Matteo De Notaris ◽  
Guadalupe Soria ◽  
Alarcon Carlos ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
7 Tesla ◽  
Superior Cerebellar Artery ◽  
Endoscopic Endonasal ◽  
Close Relationship ◽  
Fresh Frozen ◽  
Fiber Dissection ◽  
Dissection Technique ◽  
Brainstem Anatomy

Abstract BACKGROUND Treatment of intrinsic lesions of the ventral brainstem is a surgical challenge that requires complex skull base antero- and posterolateral approaches. More recently, endoscopic endonasal transclival approach (EETA) has been reported in the treatment of selected ventral brainstem lesions. OBJECTIVE In this study we explored the endoscopic ventral brainstem anatomy with the aim to describe the degree of exposure of the ventral safe entry zones. In addition, we used a newly developed method combining traditional white matter dissection with high-resolution 7T magnetic resonance imaging (MRI) of the same specimen coregistered using a neuronavigation system. METHODS Eight fresh-frozen latex-injected cadaver heads underwent EETA. Additional 8 formalin-fixed brainstems were dissected using Klingler technique guided by ultra-high resolution MRI. RESULTS The EETA allows a wide exposure of different safe entry zones located on the ventral brainstem: the exposure of perioculomotor zone requires pituitary transposition and can be hindered by superior cerebellar artery. The peritrigeminal zone was barely visible and its exposure required an extradural anterior petrosectomy. The anterolateral sulcus of the medulla was visible in most of specimens, although its close relationship with the corticospinal tract makes it suboptimal as an entry point for intrinsic lesions. In all cases, the use of 7T-MRI allowed the identification of tiny fiber bundles, improving the quality of the dissection. CONCLUSION Exposure of the ventral brainstem with EETA requires mastering surgical maneuvers, including pituitary transposition and extradural petrosectomy. The correlation of fiber dissection with 7T-MRI neuronavigation significantly improves the understanding of the brainstem anatomy.

scholarly journals A High-Resolution Interactive Atlas of the Human Brainstem Using Magnetic Resonance Histology

Neurosurgery ◽  
2020 ◽  
Vol 67 (Supplement_1) ◽  
Author(s):  
Syed M Adil ◽  
Evan Calabrese ◽  
Lefko T Charalambous ◽  
James Cook ◽  
Shervin Rahimpour ◽  
...  
Keyword(s):  
White Matter ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Spatial Resolution ◽  
7 Tesla ◽  
Acquisition Time ◽  
Superior Cerebellar Peduncle ◽  
Corticospinal Tracts ◽  
Custom Made ◽  
And Diffusion

Abstract INTRODUCTION Traditional atlases of the human brainstem are limited by the inflexible, sparsely-sampled, two-dimensional nature of histology or the low spatial resolution of magnetic resonance imaging (MRI). Magnetic resonance histology (MRH) uses postmortem high-resolution MRI to circumvent the challenges associated with both modalities. METHODS A human brainstem specimen extending from the rostral diencephalon through the caudal medulla was removed from a 65-year-old male within 24 hours of death. The specimen was formalin-fixed for two weeks, then rehydrated and placed in a custom-made MRI compatible tube and immersed in buffered liquid fluorocarbon. MRI was performed in a 7-Tesla machine with 120 unique diffusion directions. Acquisition time for anatomic and diffusion images were 14 hours and 208 hours, respectively. Segmentation was performed manually. Deterministic fiber tractography was done using strategically chosen regions of interest and avoidance, with manual editing using expert knowledge of human neuroanatomy. RESULTS Anatomic and diffusion images were rendered with isotropic resolutions of 50 μm and 200 μm, respectively. Spatial resolution was high enough to visualize individual fasciculi of the descending corticospinal tracts intercalated between the transverse pontocerebellar fibers. Ninety different structures were segmented and 11 different fiber bundles were rendered with tractography. Angular resolution was high enough to visualize crossing fibers, such as those of the superior cerebellar peduncle. Both gray and white matter can be visualized in 3D simultaneously, such as the subthalamic nuclei and corticospinal tracts, as may be used in deep brain stimulation. CONCLUSION We used MRH to enable unprecedented resolution in digital imaging of the human brainstem and adjacent diencephalic structures, and we then performed comprehensive segmentation and tractography to render an interactive, three-dimensional atlas of both gray and white matter. This atlas has immediate applications in neuroanatomical study and education, with the potential for future neurosurgical applications in enhancing neurosurgical planning through “safe” zones of entry into the human brainstem. We are currently building the computer infrastructure to make this atlas publicly-available.

scholarly journals Investigating disparity organisation in the human early visual cortex with high resolution magnetic resonance imaging (7 Tesla)

2012 ◽  
Vol 12 (9) ◽  
pp. 41-41
Author(s):  
G. S. L. Coullon ◽  
R. M. Sanchez-Panchuelo ◽  
S. Francis ◽  
D. Schluppeck ◽  
A. J. Parker ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Visual Cortex ◽  
Magnetic Resonance ◽  
High Resolution ◽  
7 Tesla ◽  
Resonance Imaging ◽  
Early Visual Cortex

Value of 3-Dimensional High-Resolution Magnetic Resonance Imaging in Detecting the Offending Vessel in Hemifacial Spasm

Neurosurgery ◽  
2013 ◽  
Vol 73 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Ehab El Refaee ◽  
Soenke Langner ◽  
Joerg Baldauf ◽  
Marc Matthes ◽  
Michael Kirsch ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Facial Nerve ◽  
Hemifacial Spasm ◽  
Observer Agreement ◽  
Resonance Imaging ◽  
3 Dimensional ◽  
Tof Mra ◽  
Simple Compression

Abstract BACKGROUND: High-resolution 3-dimensional (3-D) magnetic resonance imaging (MRI) is widely used to predict the neurovascular anatomy within the cerebellopontine angle. OBJECTIVE: To assess the value of 3-D steady-state free precession imaging (SSFP) and time-of-flight magnetic resonance angiography (TOF MRA) in detecting the offending vessels in hemifacial spasm in comparison to intraoperative endoscopic visualization. METHODS: 42 patients underwent endoscope-assisted microvascular decompression (MVD). All available preoperative 3-D SSFP and TOF MRA images were checked. Intraoperative videos were captured by a high-definition endoscopic camera attached to endoscopes while exploring the area of facial nerve root exit zone (REZ). Evaluation of the 3-D images was performed by 2 independent groups of observers and compared with the operative findings. RESULTS: Three-D MRI had an average positive predictive value (PPV) of 89.1% in differentiating between simple and complex compression. Mean accuracy of the images in detection of the offending vessels was 83.3% and 77% according to the first and second groups of observers, respectively. Averaged inter-observer agreement between the 2 groups of observers was substantial, with an averaged Kappa coefficient (K) of 0.56. In the simple compression group, mean accuracy was 97% and 89.4% according to the first and second groups of observers, respectively. Averaged K for agreement was substantial (K = 0.65). CONCLUSION: According to endoscopic visualization, 3-D SSFP and TOF MRA images are accurate in detecting the offending vessels in simple compression of the facial nerve, and in predicting presence of a complex compression with variable sensitivity in identifying all offending vessels.

scholarly journals Velocity and Pulsatility Measures in the Perforating Arteries of the Basal Ganglia at 3T MRI in Reference to 7T MRI

2021 ◽  
Vol 15 ◽  
Author(s):  
Tine Arts ◽  
Timion A. Meijs ◽  
Heynric Grotenhuis ◽  
Michiel Voskuil ◽  
Jeroen Siero ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Flow Velocity ◽  
Signal To Noise Ratio ◽  
Statistical Significance ◽  
7 Tesla ◽  
3T Mri ◽  
Perforating Artery ◽  
Artery Flow ◽  
Mri Measurements ◽  
Perforating Arteries

Cerebral perforating artery flow velocity and pulsatility can be measured using 7 tesla (T) MRI. Enabling these flow metrics on more widely available 3T systems would make them more employable. It is currently unknown whether these measurements can be performed at 3T MRI due to the lower signal-to-noise ratio (SNR). Therefore, the aim of this study is to investigate if flow velocity and pulsatility in the perforating arteries of the basal ganglia (BG) can be measured at 3T MRI and assess the agreement with 7T MRI measurements as reference. Twenty-nine subjects were included, of which 14 patients with aortic coarctation [median age 29 years (21–72)] and 15 controls [median age 27 years (22–64)]. Using a cardiac-gated 2D phase-contrast MRI sequence BG perforating arteries were imaged at 3T and 7T MRI and perforating artery density (Ndensity, #/cm2), flow velocity (Vmean, cm/s) and pulsatility index (PI) were determined. Agreement between scanner modalities was assessed using correlation and difference plots with linear regression. A p-value ≤ 0.05 indicated statistical significance. It was shown that perforating artery flow velocity and pulsatility can be measured at 3T MRI (Ndensity = 0.21 ± 0.11; Vmean = 6.04 ± 1.27; PI = 0.49 ± 0.19), although values differed from 7T MRI measurements (Ndensity = 0.95 ± 0.21; Vmean = 3.89 ± 0.56; PI = 0.28 ± 0.08). The number of detected arteries was lower at 3T (5 ± 3) than 7T MRI (24 ± 6), indicating that 3T MRI is on average a factor 4.8 less sensitive to detect cerebral perforating arteries. Comparison with 7T MRI as reference showed some agreement in Ndensity, but little to no agreement for Vmean and PI. Equalizing the modalities’ sensitivity by comparing the detected arteries on 7T MRI with the highest velocity with all vessels detected on 3T MRI, showed some improvement in agreement for PI, but not for Vmean. This study shows that it is possible to measure cerebral perforating artery flow velocity and pulsatility at 3T MRI, although an approximately fivefold sample size is needed at 3T relative to 7T MRI for a given effect size, and the measurements should be performed with equal scanner field strength and protocol.

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