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 'T1 Weighted' 
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Result : Searchterm 'T1 Weighted' found in 3 terms [] and 53 definitions []
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Searchterm 'T1 Weighted' was also found in the following services: 
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News  (2)  Resources  (1)  Forum  (4)  
 
Gastrointestinal ImagingMRI Resource Directory:
 - Abdominal Imaging -
 
Rectal staging is necessary for the preoperative assessment of intra- and extramural tumor infiltration or the decision for adjuvant radio-chemotherapy. One indication of MRI with luminal contrast enhancement is small bowel enteroclysis after duodenal intubation for visualization of inflammatory bowel wall thickening and other complications.
"Double contrast" enhancement of the bowel lumen is the administration of plain water or water with methylcellulose along with heavily T2 weighted sequences or contrast enhanced T1 weighted sequences.
Several oral contrast agents have been used for small bowel MRI: Mannitol, metamucil, locust bean gum, and PEG. All provide sufficient bowel distension and homogeneity, but suffer from side effects such as diarrhea. The volume of PEG or mannitol administered must be not too large in order to achieve the best compromise between distension and acceptance by the patient.
MR colonography with positive bowel lumen enhancement requires higher concentrations of paramagnetic agents compared to the available dedicated enteral contrast agents, IV compounds are used to dope water enemas for this purpose.
Some investigators advocate negative bowel enhancement with Contrast Agents to suppress high signal bowel content in MRCP ( Magnetic resonance cholangiopancreaticography ). The use of a mixture of metamucil and 20 ml of gadolinium chelate provides good homogeneity and good tolerance without diarrhea.
 
Images, Movies, Sliders:
 MR Colonography Gadolinium per Rectum  Open this link in a new window
      

Courtesy of  Robert R. Edelman
 Pregnancy and Small Bowel Obstruction  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 
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• View the NEWS results for 'Gastrointestinal Imaging' (1).Open this link in a new window.
 
Further Reading:
  Basics:
Nottingham scientists exploit MRI technology to assist in the treatment of IBS
Thursday, 9 January 2014   by www.news-medical.net    
Hydro-MRI of the Small Bowel: Effect of Contrast Volume, Timing of Contrast Administration, and Data Acquisition on Bowel Distention
Sunday, 1 October 2006   by www.ajronline.org    
Usefulness of MR Imaging for Diseases of the Small Intestine: Comparison with CT
2000   by www.ncbi.nlm.nih.gov    
  News & More:
Advancing Clinical Trials with Medical Imaging: Spotlight on Immunologic Diseases
Tuesday, 28 April 2015   by www.clinicalleader.com    
MRI Resources 
Manufacturers - Shoulder MRI - MRI Centers - MRI Reimbursement - Non-English - Homepages
 
Gastrointestinal Paramagnetic Contrast AgentsInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
Paramagnetic substances, for example Gd-DTPA solutions, are used as MRI oral contrast agents in gastrointestinal imaging to depict the lumen of the digestive organs. Different Gd-DTPA solutions or zeolites containing gadolinium can be used e.g., for diagnosis of delayed gastric emptying, diagnosis of Crohn's disease etc.
Low concentrations of gastrointestinal paramagnetic contrast agents cause a reduction in T1 relaxation time; consequently, these agents act on T1 weighted images by increasing the signal intensity of the bowel lumen. High concentrations cause T2 shortening by decreasing the signal, similar to superparamagnetic iron oxide. Gd-DTPA chelates are unstable at the low pH in the stomach, therefore buffering is necessary for oral use.
See also Gadopentetate Gastrointestinal, Gadolinium Zeolite, Negative Oral Contrast Agents, Gastrointestinal Superparamagnetic Contrast Agents, and Ferric ammonium citrate.
 
Images, Movies, Sliders:
 MR Colonography Gadolinium per Rectum  Open this link in a new window
      

Courtesy of  Robert R. Edelman
 
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• View the DATABASE results for 'Gastrointestinal Paramagnetic Contrast Agents' (5).Open this link in a new window

MRI Resources 
MRI Physics - Equipment - Manufacturers - MRCP - Education - Safety pool
 
Gradient Echo Multi SliceInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
(GEMS) This pulse sequence uses a changeable flip angle instead of a 90° pulse and a gradient instead of a RF pulse to rephase the FID.
T2*, T1 weighted and proton density images can be acquired. The flip angle in combination with the TR determines the T1 weighting and the TE controls the amount of dephasing. To minimize T2* the echo time should be short.
See also Gradient Echo Sequence.
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Searchterm 'T1 Weighted' was also found in the following services: 
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News  (2)  Resources  (1)  Forum  (4)  
 
Hepatobiliary Contrast AgentsInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
The characteristics of a hepatobiliary contrast agent are specific liver uptake and excretion via the biliary system. The paramagnetic substance (e.g. manganese, gadolinium) is taken up by normal hepatocytes. Diseased liver tissue did not include hepatocytes or their function is disturbed. Therefore, the signal of healthy liver tissue increases on T1 weighted sequences, but not in the liver lesions.
Another type of liver imaging contrast agent is superparamagnetic iron oxide. These particles accumulate in the reticuloendothelial system (RES) of the liver, and darken the healthy liver tissue in T2 weighted images. RES cells (including Kupffer cells) are existing in healthy liver tissue, in altered tissue with reduced RES activity or without RES cells the contrast agent concentration is also low or not existing, which improves the liver to lesion contrast.
Benefits of hepatobiliary contrast agents:
Liver lesions (e.g., tumor, metastases, haemangioma etc.) are better detectable and to characterize.
These contrast agents are useful to analyze and evaluate the liver function (in cases of diffuse liver diseases e.g., cirrhosis).
Imaging of the gallbladder and biliary system is improved.
Differences of a hepatobiliary contrast agent compared with a targeted contrast agent for Kupffer cells:
The higher number of hepatocytes than Kupffer cells improves the uptake effectiveness of the contrast agent.
Hepatobiliary contrast agents enable a better opacification of the biliary ducts and the gallbladder caused by the biliary excretion.
Hepatobiliary contrast media are fast excreted agents. RES targeted contrast agents remain longer in the body, a fact that can increase possible side effects.
See also Superparamagnetic Contrast Agents, Hepatobiliary Chelates, Liver Imaging, Endorem™, Primovist™, and Classifications, Characteristics, etc.

See also the related poll result: 'The development of contrast agents in MRI is'
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• View the DATABASE results for 'Hepatobiliary Contrast Agents' (11).Open this link in a new window

 
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    
  News & More:
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    
EMA's final opinion confirms restrictions on use of linear gadolinium agents in body scans
Friday, 21 July 2017   by www.ema.europa.eu    
MAGNETIC RESONANCE IMAGING OF FOCAL LIVER LESIONS(.pdf)
2002
MRI Resources 
Corporations - DICOM - Resources - Libraries - MRI Reimbursement - IR
 
In Phase Image
 
The term in phase refers to an image in which the signals from two spectral components (such as fat and water) add constructively in a voxel. T1 weighted in phase images are acquired by a gradient echo-based technique with a short TR, TE and a high flip angle greater than 60 degrees. To some degree, in phase sequences are more sensitive to detection of focal hepatic lesions than out of phase for evaluating reduced lesion-to-liver contrast, but the choice for a T1 gradient echo sequence is still based on field strength, advanced imaging techniques (breath hold imaging), and physician preference.
 
Images, Movies, Sliders:
 MRI Liver In Phase  Open this link in a new window
    
 
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• View the DATABASE results for 'In Phase Image' (4).Open this link in a new window

 
Further Reading:
  Basics:
Artifacts in MRI
Saturday, 1 October 2011   by www.huc.min-saude.pt    
  News & More:
Direct Water and Fat Determination in Two-Point Dixon Imaging
April 2013   by scholarship.rice.edu    
MRI Resources 
MRA - Patient Information - Spectroscopy - Breast MRI - Implant and Prosthesis - Fluorescence
 
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