SU-FF-I-57: MR Image Quality Testing of K-Space- and Image-Based Parallel Imaging Techniques Using the ACR Phantom

2006 ◽  
Vol 33 (6Part3) ◽  
pp. 2009-2010
Author(s):  
CC Chen ◽  
YY Wai ◽  
HL Liu
Keyword(s):  
Image Quality ◽  
Parallel Imaging ◽  
Imaging Techniques ◽  
Mr Image ◽  
Quality Testing

scholarly journals Penerapan Teknik Parallel Imaging Pada Pesawat MRI 0,35 Tesla Untuk Optimalisasi Kualitas Informasi Anatomi Pada MRI Lumbal Pembobotan T1WI dan T2WI Potongan Sagital

2015 ◽  
Vol 1 (1) ◽  
pp. 19-22
Author(s):  
Gatot Murti Wibowo ◽  
Dartini Dartini ◽  
Hari Prayitno
Keyword(s):  
Image Quality ◽  
Parallel Imaging ◽  
Imaging Techniques ◽  
Spin Echo ◽  
Clinical Image ◽  
Good Imaging ◽  
Scan Time ◽  
Significant Difference ◽  
Lumbar Mri

Background : Parallel imaging is one of the MRI Scanning techniques used to reduce the overall scan time when the patients with unvoluntary movement being examined with a low magnetic field of 0,35 T.  This research aims to determine the difference between the clinical image quality of the conventional turbo spin echo (TSE) with mSENSE and that of the TSE with GRAPPA parallel imaging techniques from which resulting the MRI T1 and T2 Weighted Images (T1WI and T2WI) sagittal view of lumbar spines, and to define the techniques that clinically provide the most approriate anatomical information.Methods :  This experimental study is made performed by the MRI 0.35 T in which 10 patients who had hernia nucleus pulposus (HNP) desease participated in the experiments ramdomly. The appointed Radiologists blended in the image evaluation using an image checklist to assess the visualisation of anatomical organs on the resulted sagittal lumbar MRI T1WI and T2WI. The two non-parametric statistical tools, Friedman test and the post hoc Wilcoxon matched pairs test, is used to analyze all the data descriptively. Testing the resesearch hypotheses with 95% of confident interval is to proved the differences between resulted sagittal lumbar MRI T1WI and T2WI..Results : The results shown there is a significant difference on the image quality of anatomical information when conventional TSE, parallel imaging-mSENSE and -GRAPPA, with T1WI are applied in the imaging techniques. When those imaging techniques are employed to obtain T2WI, the result is not significant in  contrast.Conclusion : Good imaging techniques with adequate clinical image quality are ranked sequently as the conventional TSE, the  mSENSE and GRAPPA.

scholarly journals Feasibility of Total Variation Noise Reduction Algorithm According to Various MR-Based PET Images in a Simultaneous PET/MR System: A Phantom Study

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 319
Author(s):  
Chan-Rok Park ◽  
Seong-Hyeon Kang ◽  
Young-Jin Lee
Keyword(s):  
Image Quality ◽  
Noise Reduction ◽  
Total Variation ◽  
Parallel Imaging ◽  
Pulse Sequence ◽  
Reduction Algorithm ◽  
Median Filters ◽  
Reduction Techniques ◽  
Imaging Results ◽  
Noise Reduction Algorithm

Recently, the total variation (TV) algorithm has been used for noise reduction distribution in degraded nuclear medicine images. To acquire positron emission tomography (PET) to correct the attenuation region in the PET/magnetic resonance (MR) system, the MR Dixon pulse sequence, which is based on controlled aliasing in parallel imaging, results from higher acceleration (CAIPI; MR-ACDixon-CAIPI) and generalized autocalibrating partially parallel acquisition (GRAPPA; MR-ACDixon-GRAPPA) algorithms are used. Therefore, this study aimed to evaluate the image performance of the TV noise reduction algorithm for PET/MR images using the Jaszczak phantom by injecting 18F radioisotopes with PET/MR, which is called mMR (Siemens, Germany), compared with conventional noise-reduction techniques such as Wiener and median filters. The contrast-to-noise (CNR) and coefficient of variation (COV) were used for quantitative analysis. Based on the results, PET images with the TV algorithm were improved by approximately 7.6% for CNR and decreased by approximately 20.0% for COV compared with conventional noise-reduction techniques. In particular, the image quality for the MR-ACDixon-CAIPI PET image was better than that of the MR-ACDixon-GRAPPA PET image. In conclusion, the TV noise-reduction algorithm is efficient for improving the PET image quality in PET/MR systems.

MR image quality improvement by zero-filling Fresnel transform imaging technique

2005 ◽  
Author(s):  
Bin Rong Wu ◽  
Satoshi Ito ◽  
Yoshitsugu Kamimura ◽  
Yoshifumi Yamada
Keyword(s):  
Quality Improvement ◽  
Image Quality ◽  
Imaging Technique ◽  
Mr Image ◽  
Image Quality Improvement ◽  
Fresnel Transform

scholarly journals Quiescent-Interval Single-Shot Magnetic Resonance Angiography

Diagnostics ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 84
Author(s):  
Aman Saini ◽  
Alex Wallace ◽  
Hassan Albadawi ◽  
Sailendra Naidu ◽  
Sadeer Alzubaidi ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Image Quality ◽  
Magnetic Resonance Angiography ◽  
Diagnostic Imaging ◽  
Imaging Techniques ◽  
Feasibility Studies ◽  
Subsequent Treatment ◽  
Single Shot ◽  
Contrast Enhanced ◽  
Diagnostic Imaging Techniques

Lower extremity peripheral arterial disease (PAD) is a chronic, debilitating disease with a significant global burden. A number of diagnostic imaging techniques exist, including computed tomography angiography (CTA) and contrast-enhanced magnetic resonance angiography (CEMRA), to aid in PAD diagnosis and subsequent treatment planning. Due to concerns of renal toxicity or nephrogenic systemic fibrosis (NSF) for iodinated and gadolinium-based contrasts, respectively, a number of non-enhanced MRA (NEMRA) protocols are being increasingly used in PAD diagnosis. These techniques, including time of flight and phase contrast MRA, have previously demonstrated poor image quality, long acquisition times, and/or susceptibility to artifacts when compared to existing contrast-enhanced techniques. In recent years, Quiescent-Interval Single-Shot (QISS) MRA has been developed to overcome these limitations in NEMRA methods, with promising results. Here, we review the various screening and diagnostic tests currently used for PAD. The various NEMRA protocols are discussed, followed by a comprehensive review of the literature on QISS MRA to date. A particular emphasis is placed on QISS MRA feasibility studies and studies comparing the diagnostic accuracy and image quality of QISS MRA versus other diagnostic imaging techniques in PAD.

Development of a new RF coil and γ-ray radiation shielding assembly for improved MR image quality in SPECT/MRI

2010 ◽  
Vol 55 (9) ◽  
pp. 2495-2504 ◽  
Author(s):  
Seunghoon Ha ◽  
Mark J Hamamura ◽  
Werner W Roeck ◽  
L Tugan Muftuler ◽  
Orhan Nalcioglu
Keyword(s):  
Image Quality ◽  
Radiation Shielding ◽  
Rf Coil ◽  
Mr Image ◽  
Γ Ray

scholarly journals Parallel Imaging of the Cervical Spine at 3T: Optimized Trade-Off between Speed and Image Quality

2012 ◽  
Vol 33 (10) ◽  
pp. 1867-1874 ◽  
Author(s):  
J. Fruehwald-Pallamar ◽  
P. Szomolanyi ◽  
N. Fakhrai ◽  
A. Lunzer ◽  
M. Weber ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Image Quality ◽  
Parallel Imaging ◽  
Trade Off

Temporomandibular joint: improved MR image quality with decreased section thickness.

Radiology ◽  
1992 ◽  
Vol 182 (1) ◽  
pp. 280-282 ◽  
Author(s):  
P L Westesson ◽  
E Kwok ◽  
J B Barsotti ◽  
M Hatala ◽  
D Paesani
Keyword(s):  
Image Quality ◽  
Temporomandibular Joint ◽  
Section Thickness ◽  
Mr Image

Post-mortem computed tomography: Technical principles and recommended parameter settings for high-resolution imaging

2018 ◽  
Vol 58 (1) ◽  
pp. 70-82 ◽  
Author(s):  
Dominic Gascho ◽  
Michael J. Thali ◽  
Tilo Niemann
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Imaging Techniques ◽  
Standard Procedure ◽  
Image Data ◽  
Post Mortem ◽  
Raw Data ◽  
Resolution Imaging ◽  
Technical Principles ◽  
Dose Imaging

Post-mortem computed tomography (PMCT) has become a standard procedure in many forensic institutes worldwide. However, the standard scan protocols offered by vendors are optimised for clinical radiology and its main considerations regarding computed tomography (CT), namely, radiation exposure and motion artefacts. Thus, these protocols aim at low-dose imaging and fast imaging techniques. However, these considerations are negligible in post-mortem imaging, which allows for significantly increased image quality. Therefore, the parameters have to be adjusted to achieve the best image quality. Several parameters affect the image quality differently and have to be weighed against each other to achieve the best image quality for different diagnostic interests. There are two main groups of parameters that are adjustable by the user: acquisition parameters and reconstruction parameters. Acquisition parameters have to be selected prior to scanning and affect the raw data composition. In contrast, reconstruction parameters affect the calculation of the slice stacks from the raw data. This article describes the CT principles from acquiring image data to post-processing and provides an overview of the significant parameters for increasing the image quality in PMCT. Based on the CT principles, the effects of these parameters on the contrast, noise, resolution and frequently occurring artefacts are described. This article provides a guide for the performance of PMCT in morgues, clinical facilities or private practices.

Molecular Scale Imaging With a Mutlilayer Superlens

2005 ◽  
Author(s):  
P. Chaturvedi ◽  
N. Fang
Keyword(s):  
Parallel Imaging ◽  
Imaging Techniques ◽  
Tolerance Analysis ◽  
Evanescent Waves ◽  
Image Resolution ◽  
Recent Theory ◽  
Optimized Design ◽  
Molecular Scale ◽  
Imaging Resolution ◽  
Matrix Scheme

Recent theory [1] suggested a thin negative index film should function as a “superlens”, providing image detail with resolution beyond the diffraction limit—a limitation to which all positive index optics are subject. The superlens allows the recovery of evanescent waves in the image via the excitation of surface plasmons. It has been demonstrated experimentally [2] that a silver superlens allows to resolve features well below the working wavelength. Resolution as high as 60 nanometer (λ/6) half-pitch has been achieved. This unique class of superlens will enable parallel imaging and nanofabrication in a single snapshot, a feat that are not yet available with other nanoscale imaging techniques such as atomic force microscope or scanning electron microscope. In this paper, we explore the possibility of further refining the image resolution using a multilayer superlens [3]. Using a stable transfer matrix scheme, our numerical calculations show an ultimate imaging resolution of λ/24. This is made possible using alternating stacks of alumina (Al2O3) and silver (Ag) layers to enhance a broad spectrum of evanescent waves via surface plasmon modes. Furthermore, we present the effect of alterations in number of layers and thickness to the image transfer function. With optimized design of multilayer superlens (working wavelength of 387.5nm), our study indicates the feasibility of resolving features of 16nm and below. Moreover, our tolerance analysis indicates that a 380 nm commercial light source would degrade slightly the imaging resolution to about 20nm. Preliminary experiments are ongoing to demonstrate the molecular scale imaging resolution. The development of potential low-loss and high resolution superlens opens the door to exciting applications in nanoscale optical metrology and nanomanufacturing.

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