scholarly journals Implementation of a dedicated 1.5 T MR scanner for radiotherapy treatment planning featuring a novel high-channel coil setup for brain imaging in treatment position

2020 ◽  
Author(s):  
Veit Mengling ◽  
Christoph Bert ◽  
Rosalind Perrin ◽  
Siti Masitho ◽  
Thomas Weissmann ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Brain Imaging ◽  
Treatment Planning ◽  
Signal To Noise Ratio ◽  
Motion Artifacts ◽  
Radiotherapy Treatment Planning ◽  
Tissue Contrast ◽  
Flexible Coil ◽  
Magnetic Resonance Imaging Mri

Abstract Purpose To share our experiences in implementing a dedicated magnetic resonance (MR) scanner for radiotherapy (RT) treatment planning using a novel coil setup for brain imaging in treatment position as well as to present developed core protocols with sequences specifically tuned for brain and prostate RT treatment planning. Materials and methods Our novel setup consists of two large 18-channel flexible coils and a specifically designed wooden mask holder mounted on a flat tabletop overlay, which allows patients to be measured in treatment position with mask immobilization. The signal-to-noise ratio (SNR) of this setup was compared to the vendor-provided flexible coil RT setup and the standard setup for diagnostic radiology. The occurrence of motion artifacts was quantified. To develop magnetic resonance imaging (MRI) protocols, we formulated site- and disease-specific clinical objectives. Results Our novel setup showed mean SNR of 163 ± 28 anteriorly, 104 ± 23 centrally, and 78 ± 14 posteriorly compared to 84 ± 8 and 102 ± 22 anteriorly, 68 ± 6 and 95 ± 20 centrally, and 56 ± 7 and 119 ± 23 posteriorly for the vendor-provided and diagnostic setup, respectively. All differences were significant (p > 0.05). Image quality of our novel setup was judged suitable for contouring by expert-based assessment. Motion artifacts were found in 8/60 patients in the diagnostic setup, whereas none were found for patients in the RT setup. Site-specific core protocols were designed to minimize distortions while optimizing tissue contrast and 3D resolution according to indication-specific objectives. Conclusion We present a novel setup for high-quality imaging in treatment position that allows use of several immobilization systems enabling MR-only workflows, which could reduce unnecessary dose and registration inaccuracies.

Magnetic resonance imaging (MRI): considerations and applications in radiotherapy treatment planning

1997 ◽  
Vol 42 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Vincent S. Khoo ◽  
David P. Dearnaley ◽  
David J. Finnigan ◽  
Anwar Padhani ◽  
Steven F. Tanner ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Treatment Planning ◽  
Resonance Imaging ◽  
Radiotherapy Treatment Planning ◽  
Magnetic Resonance Imaging Mri ◽  
Radiotherapy Treatment

Systematic Analysis and Review of Magnetic Resonance Imaging (MRI) Reconstruction Techniques

2021 ◽  
Vol 16 ◽  
Author(s):  
Penta Anil Kumar ◽  
R. Gunasundari ◽  
R. Aarthi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Optimization Technique ◽  
Motion Artifacts ◽  
Reconstruction Technique ◽  
Resonance Imaging ◽  
Research Gaps ◽  
Conventional Mri ◽  
Mri Reconstruction ◽  
Magnetic Resonance Imaging Mri

Background: Magnetic Resonance Imaging (MRI) plays an important role in the field of medical diagnostic imaging as it poses non-invasive acquisition and high soft-tissue contrast. However, the huge time is needed for the MRI scanning process that results in motion artifacts, degrades image quality, misinterpretation of data, and may cause uncomfortable to the patient. Thus, the main goal of MRI research is to accelerate data acquisition processing without affecting the quality of the image. Introduction: This paper presents a survey based on distinct conventional MRI reconstruction methodologies. In addition, a novel MRI reconstruction strategy is proposed based on weighted Compressive Sensing (CS), Penalty-aided minimization function, and Meta-heuristic optimization technique. Methods: An illustrative analysis is done concerning adapted methods, datasets used, execution tools, performance measures, and values of evaluation metrics. Moreover, the issues of existing methods and the research gaps considering conventional MRI reconstruction schemes are elaborated to obtain improved contribution for devising significant MRI reconstruction techniques. Results: The proposed method will reduce conventional aliasing artifacts problems, may attain lower Mean Square Error (MSE), higher Peak Signal-to-Noise Ratio (PSNR), and Structural SIMilarity (SSIM) index. Conclusion: The issues of existing methods and the research gaps considering conventional MRI reconstruction schemes are elaborated to devising an improved significant MRI reconstruction technique.

scholarly journals A study of the sensitivity and specificity of the Magnetic Resonance Imaging (MRI) technique used in the diagnosis of endometriosis versus the intraoperative appearance considered the reference standard in the diagnosis of endometriosis

2021 ◽  
Vol 28 (1) ◽  
pp. 55-61
Author(s):  
Alexandra RADU ◽  
◽  
Elvira BRATILA ◽  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Sensitivity And Specificity ◽  
Reference Standard ◽  
Resonance Imaging ◽  
First Line ◽  
Magnetic Resonance Imaging Mri ◽  
Asymptomatic Women ◽  
Bladder Invasion

Endometriosis is a gynecological pathology with chronic symptoms, which negatively affects the patient’s quality of life. The prevalence of endometriosis in asymptomatic women is between 2% and 50%, depending on the populations studied and the method of diagnosis. The severity of the symptoms as well as the probability of diagnosing endometriosis increases with age9. Because endometriosis is a gynecological condition with a nonspecific clinical picture, sometimes even asymptomatic, imaging technology can be considered the first line of diagnosis for this pathology. The main objective of this study is to evaluate the sensitivity and specificity of nuclear magnetic resonance imaging (MRI) used in the diagnosis of endometriotic lesions depending on their location, and compare the results obtained with the intraoperative appearance considered a reference standard in the diagnosis of endometriosis. Our study revealed the highest specificity for MRI in the case of endometriotic bladder invasion, respectively the highest sensitivity for endometriotic rectal nodules.

scholarly journals In vivo imaging techniques: a new era for histochemical analysis

2016 ◽  
Author(s):  
A. Busato ◽  
P. Fumene Feruglio ◽  
P.P. Parnigotto ◽  
P. Marzola ◽  
A. Sbarbati
Keyword(s):  
Magnetic Resonance ◽  
In Vivo Imaging ◽  
Diffusion Tensor ◽  
Technological Development ◽  
Imaging Techniques ◽  
Resonance Spectroscopy ◽  
Preclinical Research ◽  
Tissue Contrast ◽  
Magnetic Resonance Imaging Mri

In vivo imaging techniques can be integrated with classical histochemistry to create an actual histochemistry of water. In particular, Magnetic Resonance Imaging (MRI), an imaging technique primarily used as diagnostic tool in clinical/preclinical research, has excellent anatomical resolution, unlimited penetration depth and intrinsic soft tissue contrast. Thanks to the technological development, MRI is not only capable to provide morphological information but also and more interestingly functional, biophysical and molecular. In this paper we describe the main features of several advanced imaging techniques, such as MRI microscopy, Magnetic Resonance Spectroscopy, functional MRI, Diffusion Tensor Imaging and MRI with contrast agent as a useful support to classical histochemistry.

scholarly journals Magnetic resonance imaging of salivary glands

2019 ◽  
Author(s):  
Danielle Ayumi Nishimura ◽  
Ana Luiza Esteves Carneiro ◽  
Kaisermann Costa ◽  
Wladimir Gushiken de Campos ◽  
Jefferson Xavier de Oliveira ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Salivary Glands ◽  
Imaging Techniques ◽  
Neck Region ◽  
Evaluation Instrument ◽  
Resonance Imaging ◽  
Tissue Contrast ◽  
Excellent Method ◽  
Magnetic Resonance Imaging Mri

Salivary glands tumors account for 2-5% of tumors in the head and neck region, possibly being benign or malignant. Magnetic resonance imaging (MRI) presents high soft tissue contrast resolution, thus being an excellent method for salivary gland analysis. The objective of this literature review is to analyze MRI as an evaluation instrument for the diagnosis of salivary glands lesions. Compared to other imaging techniques, MRI can better evaluate the relationship between adjacent anatomical structures, presenting greater sensitivity and specificity.

scholarly journals T2-Weighted 4D Magnetic Resonance Imaging for Application in Magnetic Resonance–Guided Radiotherapy Treatment Planning

2017 ◽  
Vol 52 (10) ◽  
pp. 563-573 ◽  
Author(s):  
Joshua N. Freedman ◽  
David J. Collins ◽  
Hannah Bainbridge ◽  
Christopher M. Rank ◽  
Simeon Nill ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Treatment Planning ◽  
Resonance Imaging ◽  
Radiotherapy Treatment Planning ◽  
Radiotherapy Treatment

RFID-Based Real-Time Navigation for Interventional Magnetic Resonance Imaging: Development and Evaluation of a Novel Tracking System

2017 ◽  
Vol 11 (3) ◽  
Author(s):  
Felix Güttler ◽  
Andreas Heinrich ◽  
Peter Krauß ◽  
Jonathan Guntermann ◽  
Maximilian de Bucourt ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Spatial Resolution ◽  
Radio Frequency Identification ◽  
Signal To Noise Ratio ◽  
Tracking System ◽  
Single Shot ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri ◽  
Steady State Precession

The purpose of this study was to evaluate the suitability of a novel radio-frequency identification (RFID)-based tracking system for intraoperative magnetic resonance imaging (MRI). A RFID tracking system was modified to fulfill MRI-compatibility and tested according to ASTM and NEMA. The influence of the RFID tracking system on MRI was analyzed in a phantom study using a half-Fourier acquisition single-shot turbospin echo (HASTE) and true fast imaging with steady-state precession sequence (TrueFISP) sequence. The RFID antenna was gradually moved closer to the isocenter of the MR scanner from 90 to 210 cm to investigate the influence of the distance. Furthermore, the RF was gradually changed between 865 and 869 MHz for a distance of 90 cm, 150 cm, and 210 cm to the isocenter of the magnet to investigate the influence of the frequency. The specific spatial resolution was measured with and without a permanent line of sight (LOS). After the modification of the reader, no significant change of the signal-to-noise ratio (SNR) could be observed with increasing distance of the RFID tracking system to the isocenter of the MR scanner. Also, different radio frequencies of the RFID tracking system did not influence the SNR of the MR-images significantly. The specific spatial resolution deviated on average by 8.97 ± 7.33 mm with LOS and 11.23 ± 12.03 mm without LOS from the reference system. The RFID tracking system had no relevant influence on the MR-image quality. RFID tracking solved the LOS problem. However, the spatial accuracy of the RFID tracking system has to be improved for medical usage.

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