Temporal Bone Imaging Techniques: Computer Tomography, Cone Beam CT and Magnetic Resonance Imaging

2021 ◽  
pp. 21-24
Author(s):  
Geoiphy George Pulickal
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Temporal Bone ◽  
Computer Tomography ◽  
Imaging Techniques ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Bone Imaging ◽  
Resonance Imaging ◽  
Temporal Bone Imaging

scholarly journals Clinically Delivered Treatment for Glioma Patients on a Hybrid Magnetic Resonance Imaging (MRI)-Linear Accelerator (MR-Linac) and a Cone Beam CT (CBCT)-Guided Linac: Dosimetric Comparisons with In Vivo Skin Dose Correlation

2021 ◽  
Author(s):  
Michael H. Wang ◽  
Anthony Kim ◽  
Mark Ruschin ◽  
Hendrick Tan ◽  
Hany Soliman ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Monte Carlo ◽  
Magnetic Resonance ◽  
Linear Accelerator ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Skin Dose ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

Abstract Background Magnetic Resonance Imaging (MRI)-Linear Accelerator (MR-Linac) radiotherapy requires special consideration for secondary electron interactions within the magnetic field, which can alter dose deposition at air-tissue interfaces. Methods Thirty-seven consecutive glioma patients treated during their radiotherapy course with at least one fraction delivered on MR-Linac or Cone Beam CT (CBCT)-guided Linac, were analyzed. Treatment planning for both systems were completed prior to radiotherapy initiation and approved for clinical delivery using commercial treatment planning systems (TPS): a Monte Carlo calculation-based or convolution calculation-based TPS for MR-Linac or CBCT-Linac, respectively. Dosimetric parameters for planning target volume (PTV), organs-at-risk (OARs), and air-tissue interface were compared. In vivo skin dose during a single fraction of MR-Linac and CBCT-Linac treatment was measured using an Optically Stimulated Luminescent Dosimeter (OSLD) and correlated with TPS skin dose. Results Monte Carlo-based MR-Linac plans and convolution-based CBCT-Linac plans exhibited minimal differences in PTV and OAR parameters. However, MR-Linac plans had greater doses within tissues surrounding air cavities (1.52 Gy higher mean Dmean, p < 0.0001) and skin (1.10 Gy higher mean Dmean, p < 0.0001). In vivo OSLD skin readings were 14.5% greater for MR-Linac treatments (p = 0.0027), and were more accurately predicted by Monte Carlo-based calculation (ρ = 0.95, p < 0.0001) vs. convolution-based (ρ = 0.80, p = 0.0096). Conclusions The magnetic field’s dosimetric impact was minimal for PTV and OARs in glioma as compared to standard CBCT-Linac treatment plans. However, skin doses were significantly greater with the MR-Linac and correlated with in vivo measurements. Future MR-Linac planning processes are being designed to account for skin dosimetry and treatment delivery.

scholarly journals Wykorzystanie obrazowania rezonansem magnetycznym w radioterapii (planowanie leczenia i procedury IGRT) oraz związana z tym rola elektroradiologa

2017 ◽  
Vol 14 (3) ◽  
pp. 69-74
Author(s):  
Elżbieta Czajka
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

Wykorzystanie rezonansu magnetycznego (ang. magnetic resonance imaging, MRI) w radioterapii jest często poruszanym zagadnieniem w ostatnich latach. Osobny blok wystąpień poświęcony temu tematowi pojawił się również w części programu dedykowanej elektroradiologom na 3rd ESTRO FORUM. Podczas wystąpień omówiono trzy obszary, w których możliwe jest wykorzystanie rezonansu magnetycznego w radioterapii, tj. 1) akwizycja obrazów niezbędnych do planowania leczenia 2) planowanie leczenia w systemie komputerowym w oparciu o obrazowanie rezonansem magnetycznym oraz 3) realizacja leczenia na aparacie terapeutycznym. Zastąpienie w łańcuchu terapeutycznym przede wszystkim tomografii komputerowej (ang. computed tomography, CT) ale również w dalszym etapie innych metod obrazowania, wykorzystujących promieniowanie rentgenowskie np. CBCT (ang. cone beam CT), MVCT (ang. mega voltage CT) lub kVCT (ang. kilo voltage CT) rezonansem magnetycznym, wprowadza do radioterapii tzw. „full-MR workflow”, czyli koncepcję radioterapii opartej wyłącznie o obrazowanie rezonansem magnetycznym. Analiza wybranych doniesień ma na celu przybliżenie czytelnikowi tego zagadnienia, omówienie jego zalet i potencjalnych ograniczeń, ale również umiejscowienie elektroradiologia w całym procesie radioterapeutycznym opartym o rezonans magnetyczny.

scholarly journals Clinically Delivered Treatment for Glioma Patients on Hybrid Magnetic Resonance Imaging (MRI)-Linear Accelerator (MR-Linac) versus Cone Beam CT (CBCT)-Guided Linac

2021 ◽  
Author(s):  
Michael H. Wang ◽  
Anthony Kim ◽  
Mark Ruschin ◽  
Hendrick Tan ◽  
Hany Soliman ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Monte Carlo ◽  
Magnetic Resonance ◽  
Linear Accelerator ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Skin Dose ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

Abstract Magnetic Resonance Imaging (MRI)-Linear Accelerator (MR-Linac) radiotherapy is an innovative technology that requires special consideration for secondary electron interactions within the magnetic field, which can alter dose deposition at air-tissue interfaces. Thirty-seven consecutive glioma patients had treatment planning completed and approved prior to radiotherapy initiation using commercial treatment planning systems (TPS): a Monte Carlo-based or convolution-based TPS for MR-Linac or Cone Beam CT (CBCT)-guided Linac, respectively. In vivo skin dose was measured using an Optically Stimulated Luminescent Dosimeter (OSLD) and correlated with TPS skin dose. We found that Monte Carlo-based MR-Linac plans and convolution-based CBCT-Linac plans had similar dosimetric parameters for target volumes and organs-at-risk. However, MR-Linac plans had 1.52 Gy higher mean dose to air cavities (p<0.0001) and 1.10 Gy higher mean dose to skin (p<0.0001). In vivo skin dose was 14.5% greater for MR-Linac (p=0.0027), and were more accurately predicted by Monte Carlo-based calculation (ρ=0.95, p<0.0001) vs. convolution-based (ρ=0.80, p=0.0096). This is the first prospective dosimetric comparison of glioma patients clinically treated on both MR-Linac and CBCT-guided Linac. Skin doses were significantly greater with MR-Linac and correlated with in vivo measurements. Future MR-Linac planning processes are being designed to account for skin dosimetry and treatment delivery.

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.

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.

Definitive Diagnosis and Location of Peanuts in the Airways Using Magnetic Resonance Imaging Techniques

1994 ◽  
Vol 23 (6) ◽  
pp. 1379-1382 ◽  
Author(s):  
Hitoshi Imaizumi ◽  
Masamitsu Kaneko ◽  
Satoshi Nara ◽  
Hiroko Saito ◽  
Koji Asakura ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging Techniques ◽  
Definitive Diagnosis ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Techniques

scholarly journals Tracking Transplanted Stem Cells Using Magnetic Resonance Imaging and the Nanoparticle Labeling Method in Urology

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jae Heon Kim ◽  
Hong J. Lee ◽  
Yun Seob Song
Keyword(s):  
Magnetic Resonance Imaging ◽  
Stem Cells ◽  
Molecular Imaging ◽  
Magnetic Resonance ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Image Resolution ◽  
Imaging Method ◽  
Resonance Imaging

A reliablein vivoimaging method to localize transplanted cells and monitor their viability would enable a systematic investigation of cell therapy. Most stem cell transplantation studies have used immunohistological staining, which does not provide information about the migration of transplanted cellsin vivoin the same host. Molecular imaging visualizes targeted cells in a living host, which enables determining the biological processes occurring in transplanted stem cells. Molecular imaging with labeled nanoparticles provides the opportunity to monitor transplanted cells noninvasively without sacrifice and to repeatedly evaluate them. Among several molecular imaging techniques, magnetic resonance imaging (MRI) provides high resolution and sensitivity of transplanted cells. MRI is a powerful noninvasive imaging modality with excellent image resolution for studying cellular dynamics. Several types of nanoparticles including superparamagnetic iron oxide nanoparticles and magnetic nanoparticles have been used to magnetically label stem cells and monitor viability by MRI in the urologic field. This review focuses on the current role and limitations of MRI with labeled nanoparticles for tracking transplanted stem cells in urology.

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