scholarly journals A new magnetic resonance-based technique for high-resolution quantification of amorphous and quasi-amorphous structures

2016 ◽  
Vol 13 (123) ◽  
pp. 20160589
Author(s):  
James Rafferty ◽  
Lance Farr ◽  
Tim James ◽  
David Chase ◽  
John Heinrich ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Three Dimensions ◽  
Small Scale ◽  
Micro Computed Tomography ◽  
Cross Sectional ◽  
Biological Structures ◽  
The One

We present a novel, high-resolution magnetic resonance technique, fine structure analysis (FSA) for the quantification and analysis of amorphous and quasi-amorphous biological structures. The one-dimensional technique is introduced mathematically and then applied to one simulated phantom, two physical phantoms and a set of ex vivo biological samples, scanned with interpoint spacings of 0.0038–0.195 mm and cross-sectional sizes of 3 × 3 or 5 × 5 mm. The simulated phantom and one of the physical phantoms consists of randomly arranged beads of known size in two and three dimensions, respectively. The second physical phantom was constructed by etching lines on Perspex. The ex vivo samples are human bone specimens. We show that for all three phantoms, the FSA technique is able to elucidate the average spacing of the structures present within each sample using structural spectroscopy, the smallest of which was 180 µm in size. We further show that in samples of trabecular bone, FSA is able to produce comparable results to micro-computed tomography, the current gold standard for measuring bone microstructure, but without the need for ionizing radiation. Many biological structures are too small to be captured by conventional, clinically deployed medical imaging techniques. FSA has the potential for use in the analysis of pathologies where such small-scale repeating structures are disrupted or their size, and spacing is otherwise altered.

High-Resolution Magnetic Resonance Imaging of the Human Median Nerve

2004 ◽  
Vol 18 (2) ◽  
pp. 80-87 ◽  
Author(s):  
Archie Heddings ◽  
Mehmet Bilgen ◽  
Randolph Nudo ◽  
Bruce Toby ◽  
Terence McIff ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Peripheral Nerve ◽  
Median Nerve ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Proton Density ◽  
Resonance Imaging ◽  
Imaging Protocols

Objectives. It is widely accepted that peripheral nerve repairs performed within 6 weeks of injury have much better outcomes than those performed at later dates. However, there is no diagnostic technique that can determine if a traumatic peripheral nerve injury requires surgical intervention in the early postinjury phase. The objective of this article was to determine whether novel, noninvasive magnetic resonance imaging techniques could demonstrate the microstructure of human peripheral nerves that is necessary for determining prognosis and determining if surgery is indicated following traumatic injury. Methods. Ex vivo magnetic resonance imaging protocols were developed on a 9.4-T research scanner using spin-echo proton density and gradient-echo imaging sequences and a specially designed, inductively coupled radio frequency coil. These imaging protocols were applied to in situ imaging of the human median nerve in 4 fresh-frozen cadaver arms. Results. Noninvasive high-resolution images of the human median nerve were obtained. Structures in the nerve that were observed included fascicles, interfascicular epineurium, perineurium, and intrafascicular septations. Conclusion. Application of these imaging techniques to clinical scanners could provide physicians with a tool that is capable of grading the severity of nerve injuries and providing indications for surgery in the early postinjury phase.

scholarly journals Cross-sectional anatomy, computed tomography, and magnetic resonance imaging of the banded houndshark (Triakis scyllium)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sang Wha Kim ◽  
Adams Hei Long Yuen ◽  
Cherry Tsz Ching Poon ◽  
Joon Oh Hwang ◽  
Chang Jun Lee ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Evolutionary Developmental Biology ◽  
Phylogenetic Position ◽  
Ct Scanner ◽  
Resonance Imaging ◽  
Cross Sectional

AbstractDue to their important phylogenetic position among extant vertebrates, sharks are an invaluable group in evolutionary developmental biology studies. A thorough understanding of shark anatomy is essential to facilitate these studies and documentation of this iconic taxon. With the increasing availability of cross-sectional imaging techniques, the complicated anatomy of both cartilaginous and soft tissues can be analyzed non-invasively, quickly, and accurately. The aim of this study is to provide a detailed anatomical description of the normal banded houndshark (Triakis scyllium) using computed tomography (CT) and magnetic resonance imaging (MRI) along with cryosection images. Three banded houndsharks were scanned using a 64-detector row spiral CT scanner and a 3 T MRI scanner. All images were digitally stored and assessed using open-source Digital Imaging and Communications in Medicine viewer software in the transverse, sagittal, and dorsal dimensions. The banded houndshark cadavers were then cryosectioned at approximately 1-cm intervals. Corresponding transverse cryosection images were chosen to identify the best anatomical correlations for transverse CT and MRI images. The resulting images provided excellent detail of the major anatomical structures of the banded houndshark. The illustrations in the present study could be considered as a useful reference for interpretation of normal and pathological imaging studies of sharks.

scholarly journals Measurement of three-dimensional displacement field in piled embankments using synchrotron X-ray tomography

2019 ◽  
Vol 56 (6) ◽  
pp. 885-892 ◽  
Author(s):  
Louis King ◽  
Abdelmalek Bouazza ◽  
Anton Maksimenko ◽  
Will P. Gates ◽  
Stephen Dubsky
Keyword(s):  
High Resolution ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Physical Models ◽  
Scale Model ◽  
Small Scale ◽  
Full Field ◽  
X Ray ◽  
Wide Range ◽  
Piled Embankments

The measurement of displacement fields by nondestructive imaging techniques opens up the potential to study the pre-failure mechanisms of a wide range of geotechnical problems within physical models. With the advancement of imaging technologies, it has become possible to achieve high-resolution three-dimensional computed tomography volumes of relatively large samples, which may have previously resulted in excessively long scan times or significant imaging artefacts. Imaging of small-scale model piled embankments (142 mm diameter) comprising sand was undertaken using the imaging and medical beamline at the Australian Synchrotron. The monochromatic X-ray beam produced high-resolution reconstructed volumes with a fine texture due to the size and mineralogy of the sand grains as well as the phase contrast enhancement achieved by the monochromatic X-ray beam. The reconstructed volumes were well suited to the application of digital volume correlation, which utilizes cross-correlation techniques to estimate three-dimensional full-field displacement vectors. The output provides insight into the strain localizations that develop within piled embankments and an example of how advanced imaging techniques can be utilized to study the kinematics of physical models.

Contribution of high-resolution correlative imaging techniques in the study of the liver sieve in three-dimensions

2007 ◽  
Vol 70 (3) ◽  
pp. 230-242 ◽  
Author(s):  
Filip Braet ◽  
Eddie Wisse ◽  
Paul Bomans ◽  
Peter Frederik ◽  
Willie Geerts ◽  
...  
Keyword(s):  
High Resolution ◽  
Imaging Techniques ◽  
Three Dimensions ◽  
Correlative Imaging

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

QUANTITATIVE ASSESSMENT OF GINGIVAL INFLAMMATION USING HIGH-RESOLUTION ULTRASOUNDEX-VIVO

2018 ◽  
Vol 18 (03) ◽  
pp. 1850012 ◽  
Author(s):  
AHMED M. SAYED ◽  
RACHEL LAMARCK ◽  
ELISA CRUZ ◽  
EROS CHAVES ◽  
OSAMA M. MUKDADI
Keyword(s):  
High Resolution ◽  
Ultrasound Imaging ◽  
Ex Vivo ◽  
Ultrasound Image ◽  
Strong Relationship ◽  
Ultrasound Images ◽  
Gingival Inflammation ◽  
Cross Sectional ◽  
Diagnostic Potential ◽  
Image Pairs

This study investigates the feasibility of using high-resolution ultrasound imaging echogenicity to quantitatively diagnose gingival inflammation. Gingival samples were extracted from the study participants during gingivectomy procedures. Ultrasound mechanical scanning of the samples was immediately conducted ex-vivo to render cross-sectional images of high resolution, at different locations. Samples’ histological preparation and analysis was followed after performing ultrasound imaging. Histological sections were then matched with ultrasound images at different sections for each gingival sample. The matched image pairs were used to estimate two quantitative measures; relative inflammation area and ultrasound image echogenicity. These parameters were employed to judge the diagnostic potential of gingival ultrasound imaging. The results show that ultrasound images exhibited low intensity levels at the inflamed gingival regions, while healthy layers showed higher intensity levels. The relative area parameter implied a strong relationship between ultrasound and histological images. Ultrasound echogenicity was found to be statistically significant in differentiating between some inflammation degrees in the studied gingival samples. In summary, ultrasound imaging has the potential to be a noninvasive adjunct diagnostic tool for gingival inflammation, and may help assess the stage of the disease and ultimately limit periodontal disease occurrence; taking into consideration the limits of this study.

scholarly journals Magnetic Resonance Imaging of Rectal Cancer

2019 ◽  
Vol 02 (01) ◽  
pp. 018-032
Author(s):  
Ekta Maheshwari ◽  
Gitanjali Bajaj ◽  
Kedar Jambhekar ◽  
Tarun Pandey ◽  
Roopa Ram
Keyword(s):  
Magnetic Resonance Imaging ◽  
Rectal Cancer ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Imaging Techniques ◽  
Postoperative Recurrence ◽  
Response To Therapy ◽  
Resonance Imaging ◽  
Primary Rectal Cancer ◽  
Magnetic Resonance Imaging Mri

AbstractHigh-resolution magnetic resonance imaging (MRI) plays a pivotal role in the pretreatment assessment of primary rectal cancer. The success of this technique depends on obtaining good-quality high-resolution T2-weighted images of the primary tumor, orthogonal to rectal lumen. The goal of magnetic resonance staging is to identify patients who will benefit from neoadjuvant therapy prior to surgery to minimize postoperative recurrence and planning of optimal surgical approach. MRI also facilitates optimal identification of important prognostic factors, which improves both treatment selection and posttreatment follow-up. The objective of this article is to review the existing literature and provide a concise update on various aspects of rectal cancer imaging, discuss the current role of advanced imaging techniques such as diffusion-weighted and perfusion imaging in the evaluation of rectal cancer, and to assess response to therapy.

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