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 'Chemical Shift Imaging' 
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Result : Searchterm 'Chemical Shift Imaging' found in 1 term [] and 11 definitions [], (+ 8 Boolean[] results
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Chemical Shift ImagingInfoSheet: - Sequences - 
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(CSI) Chemical shift imaging is an extension of MR spectroscopy, allowing metabolite information to be measured in an extended region and to add the chemical analysis of body tissues to the potential clinical utility of Magnetic Resonance. The spatial location is phase encoded and a spectrum is recorded at each phase encoding step to allow the spectra acquisition in a number of volumes covering the whole sample. CSI provides mapping of chemical shifts, analog to individual spectral lines or groups of lines.
Spatial resolution can be in one, two or three dimensions, but with long acquisition times od full 3D CSI. Commonly a slice-selected 2D acquisition is used. The chemical composition of each voxel is represented by spectra, or as an image in which the signal intensity depends on the concentration of an individual metabolite. Alternatively frequency-selective pulses excite only a single spectral component.
There are several methods of performing chemical shift imaging, e.g. the inversion recovery method, chemical shift selective imaging sequence, chemical shift insensitive slice selective RF pulse, the saturation method, spatial and chemical shift encoded excitation and quantitative chemical shift imaging.
See also Magnetic Resonance Spectroscopy.

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Further Reading:
  Basics:
1H MR Spectroscopy and Chemical Shift Imaging of the In Vivo Brain at 7 Tesla
Sunday, 26 November 2006   by tobias-lib.uni-tuebingen.de    
MRI evaluation of fatty liver in day to day practice: Quantitative and qualitative methods
Wednesday, 3 September 2014   by www.sciencedirect.com    
  News & More:
MRI-PDFF images successfully measure liver fat content
Tuesday, 28 February 2017   by www.healio.com    
Spin echoes, CPMG and T2 relaxation - Introductory NMR & MRI from Magritek
2013   by www.azom.com    
mDIXON being developed to simplify and accelerate liver MRI
September 2010   by incenter.medical.philips.com    
MRI Resources 
Pathology - Mass Spectrometry - Process Analysis - Safety Products - Service and Support - Libraries
 
Chemical Shift Selective Imaging SequenceInfoSheet: - Sequences - 
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Types of, 
etc.MRI Resource Directory:
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(CHESS) A sequence for water suppression in proton MR spectroscopy and for water or fat suppression in MR imaging. This technique uses a frequency-selective 90° pulse to selectively excite the water signal, followed by a spoiler gradient to dephase the resulting magnetization. The gradients may be repeated several times in different directions to increase its effectiveness.
See also Chemical Shift Imaging and Chemical Shift.

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MRI Resources 
General - PACS - Crystallography - MRI Accidents - Movies - Colonography
 
Fourier TransformationMRI Resource Directory:
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(FT) The Fourier transformation is a mathematical procedure to separate out the frequency components of a signal from its amplitudes as a function of time, or the inverse Fourier transformation (IFT) calculates the time domain from the frequency domain. The FT is used to generate the spectrum from the free induction decay or spin echo in the pulse MR technique and is essential to most MR imaging techniques. The Fourier transformation can be generalized to multiple dimensions, e.g. to relate an image to its corresponding k-space representation, or to include chemical shift information in some chemical shift imaging techniques. Fourier transformation analysis allows spatial information to be reconstructed from the raw data.
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Further Reading:
  Basics:
Fourier Transform Imaging of Spin Vortex Eigenmodes
Friday, 13 August 2004   by www.physik.uni-regensburg.de    
MR Image Reconstruction from Raw Data
   by dukemil.egr.duke.edu    
The Scientist and Engineer's Guide to Digital Signal Processing
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Hybrid Spectroscopy
 
The combination of single volume spectroscopy and chemical shift imaging. The chemical shift measurement is performed over a selectively-excited volume of interest. Areas with strong distorting signal are not stimulated and therefore do not append signal to the spectra.
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Further Reading:
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Near-IR Spectroscopy Performs Challenging Breast Imaging
Tuesday, 18 February 2014   by www.novuslight.com    
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Lung Imaging - Health - NMR - Pediatric and Fetal MRI - Coils - RIS
 
Liver ImagingForum -
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Liver imaging can be performed with sonography, computed tomography (CT) and magnetic resonance imaging (MRI). Ultrasound is, caused by the easy access, still the first-line imaging method of choice; CT and MRI are applied whenever ultrasound imaging yields vague results. Indications are the characterization of metastases and primary liver tumors e.g., benign lesions such as focal nodular hyperplasia (FNH), adenoma, hemangioma and malignant lesions (cancer) such as hepatocellular carcinomas (HCC). The decision, which medical imaging modality is more suitable, MRI or CT, is dependent on the different factors. CT is less costly and more widely available; modern multislice scanners provide high spatial resolution and short scan times but has the disadvantage of radiation exposure.
With the introduction of high performance MR systems and advanced sequences the image quality of MRI for the liver has gained substantially. Fast spin echo or single shot techniques, often combined with fat suppression, are the most common T2 weighted sequences used in liver MRI procedures. Spoiled gradient echo sequences are used as ideal T1 weighted sequences for evaluating of the liver. The repetition time (TR) can be sufficiently long to acquire enough sections covering the entire liver in one pass, and to provide good signal to noise. The TE should be the shortest in phase echo time (TE), which provides strong T1 weighting, minimizes magnetic susceptibility effects, and permits acquisition within one breath hold to cover the whole liver. A flip angle of 80° provides good T1 weighting and less of power deposition and tissue saturation than a larger flip angle that would provide comparable T1 weighting.
Liver MRI is very dependent on the administration of contrast agents, especially when detection and characterization of focal lesions are the issues. Liver MRI combined with MRCP is useful to evaluate patients with hepatic and biliary disease.
Gadolinium chelates are typical non-specific extracellular agents diffusing rapidly to the extravascular space of tissues being cleared by glomerular filtration at the kidney. These characteristics are somewhat problematic when a large organ with a huge interstitial space like the liver is imaged. These agents provide a small temporal imaging window (seconds), after which they begin to diffuse to the interstitial space not only of healthy liver cells but also of lesions, reducing the contrast gradient necessary for easy lesion detection. Dynamic MRI with multiple phases after i.v. contrast media (Gd chelates), with arterial, portal and late phase images (similar to CT) provides additional information.
An additional advantage of MRI is the availability of liver-specific contrast agents (see also Hepatobiliary Contrast Agents). Gd-EOB-DTPA (gadoxetate disodium, Gadolinium ethoxybenzyl dimeglumine, EOVIST Injection, brand name in other countries is Primovist) is a gadolinium-based MRI contrast agent approved by the FDA for the detection and characterization of known or suspected focal liver lesions.
Gd-EOB-DTPA provides dynamic phases after intravenous injection, similarly to non-specific gadolinium chelates, and distributes into the hepatocytes and bile ducts during the hepatobiliary phase. It has up to 50% hepatobiliary excretion in the normal liver.
Since ferumoxides are not eliminated by the kidney, they possess long plasmatic half-lives, allowing circulation for several minutes in the vascular space. The uptake process is dependent on the total size of the particle being quicker for larger particles with a size of the range of 150 nm (called superparamagnetic iron oxide). The smaller ones, possessing a total particle size in the order of 30 nm, are called ultrasmall superparamagnetic iron oxide particles and they suffer a slower uptake by RES cells. Intracellular contrast agents used in liver MRI are primarily targeted to the normal liver parenchyma and not to pathological cells. Currently, iron oxide based MRI contrast agents are not marketed.
Beyond contrast enhanced MRI, the detection of fatty liver disease and iron overload has clinical significance due to the potential for evolution into cirrhosis and hepatocellular carcinoma. Imaging-based liver fat quantification (see also Dixon) provides noninvasively information about fat metabolism; chemical shift imaging or T2*-weighted imaging allow the quantification of hepatic iron concentration. See also Abdominal Imaging, Primovist™, Liver Acquisition with Volume Acquisition (LAVA), T1W High Resolution Isotropic Volume Examination (THRIVE) and Bolus Injection.

For Ultrasound Imaging (USI) see Liver Sonography at US-TIP.com.
 
Images, Movies, Sliders:
 Anatomic Imaging of the Liver  Open this link in a new window
      

 MRI Liver T2 TSE  Open this link in a new window
    
 
Radiology-tip.comAbdomen CT,  Biliary Contrast Agents
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Radiology-tip.comLiver Sonography,  Vascular Ultrasound Contrast Agents
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Further Reading:
  Basics:
Contrast MRI Best at Finding Liver Trouble - But Timing Matters
Sunday, 6 March 2011   by www.searchmedica.com    
MR contrast agents: Applications in hepatobiliary imaging
Thursday, 11 November 2010   by www.appliedradiology.com    
Elastography: A Useful Method in Depicting Liver Hardness
Thursday, 15 April 2010   by www.sciencedaily.com    
Iron overload: accuracy of in-phase and out-of-phase MRI as a quick method to evaluate liver iron load in haematological malignancies and chronic liver disease
Friday, 1 June 2012   by www.ncbi.nlm.nih.gov    
MAGNETIC RESONANCE IMAGING OF FOCAL LIVER LESIONS(.pdf)
2002
  News & More:
MRI-PDFF images successfully measure liver fat content
Tuesday, 28 February 2017   by www.healio.com    
EORTC study aims to qualify ADC as predictive imaging biomarker in preoperative regimens
Monday, 4 January 2016   by www.eurekalert.org    
MRI effectively measures hemochromatosis iron burden
Saturday, 3 October 2015   by medicalxpress.com    
Total body iron balance: Liver MRI better than biopsy
Sunday, 15 March 2015   by www.eurekalert.org    
Perspectum Diagnostics Announces FDA Clearance for LiverMultiscan MR Imaging Device
Thursday, 12 November 2015   by www.fiercemedicaldevices.com    
MRI Resources 
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