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News  (28)  Resources  (5)  Forum  (67)  
 
Intera Achieva CV™InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.medical.philips.com/main/products/mri/products/intera_achievacv/ From Philips Medical Systems;
The Intera Achieva CV is focused on cardiovascular imaging research and development, generating technology on the cutting edge for modern clinical needs, like easy coronary artery imaging, the evaluation of flow effects in vessels and peripheral angiography with optimal resolution per station.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Short bore compact
Standard: Head, body, cardiac, optional phased array: Spine, pediatric, 3rd party connector; Optional SENSE? coils for all applications
Optional
SYNCHRONIZATION
ECG/peripheral: Optional/yes, respiratory gating
PULSE SEQUENCES
SE, Modified-SE, IR (T1, T2, PD), STIR, FLAIR, SPIR, FFE, T1-FFE, T2-FFE, Balanced FFE, TFE, Balanced TFE, Dynamic, Keyhole, 3D, Multi Chunk 3D, Multi Stack 3D, K Space Shutter, MTC, TSE, Dual IR, DRIVE, EPI, Cine, 2DMSS, DAVE, Mixed Mode; Angiography: Inflow MRA, TONE, PCA, CE MRA
IMAGING MODES
Single Slice 2D , Multi Single Slice 2D, Multi Slice 2D, 3D, Multi Chunk 3D, Multi Stack 3D
FOV
Over 50 cm
0.05 mm
128 x 128, 256 x 256,512 x 512,1024 x 1024 (64 for Bold img)
MEASURING MATRIX
Variable in 1% increments
PIXEL INTENSITY
Lum.: 120 cd/m2; contrast: 150:1
Variable (op. param. depend.)
60 x 60 cm
POWER REQUIREMENTS
380/400 V
CRYOGEN USE
0.03 L/hr helium
STRENGTH
up to 33 mT/m
5-GAUSS FRINGE FIELD
2.4 m / 3.8 m
Passive and dynamic
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Further Reading:
  News & More:
Coronary Artery Disease: Combined Stress MR Imaging Protocol-One-Stop Evaluation of Myocardial Perfusion and Function1
   by radiology.rsnajnls.org    
MRI Resources 
Research Labs - Musculoskeletal and Joint MRI - Services and Supplies - Shoulder MRI - Education pool - Coils
 
Liver ImagingForum -
related threadsMRI Resource Directory:
 - Liver Imaging -
 
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, Primovistâ„¢, Liver Acquisition with Volume Acquisition (LAVA), T1W High Resolution Isotropic Volume Examination (THRIVE) and Bolus Injection.

For Ultrasound Imaging (USI) see Liver Sonography at Medical-Ultrasound-Imaging.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.comradAbdomen CT,  Biliary Contrast Agents
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Medical-Ultrasound-Imaging.comLiver Sonography,  Vascular Ultrasound Contrast Agents
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• View the DATABASE results for 'Liver Imaging' (13).Open this link in a new window


• View the NEWS results for 'Liver Imaging' (10).Open this link in a new window.
 
Further Reading:
  Basics:
Comparison of liver scintigraphy and the liver-spleen contrast in Gd-EOB-DTPA-enhanced MRI on liver function tests
Thursday, 18 November 2021   by www.nature.com    
Liver Imaging Today
Friday, 1 February 2013   by www.healthcare.siemens.it    
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    
  News & More:
Utility and impact of magnetic resonance elastography in the clinical course and management of chronic liver disease
Saturday, 20 January 2024   by www.nature.com    
Even early forms of liver disease affect heart health, Cedars-Sinai study finds
Thursday, 8 December 2022   by www.eurekalert.org    
For monitoring purposes, AI-aided MRI does what liver biopsy does with less risk, lower cost
Wednesday, 28 September 2022   by radiologybusiness.com    
Perspectum: High Liver Fat (Hepatic Steatosis) Linked to Increased Risk of Hospitalization in COVID-19 Patients With Obesity
Monday, 29 March 2021   by www.businesswire.com    
EMA's final opinion confirms restrictions on use of linear gadolinium agents in body scans
Friday, 21 July 2017   by www.ema.europa.eu    
T2-Weighted Liver MRI Using the MultiVane Technique at 3T: Comparison with Conventional T2-Weighted MRI
Friday, 16 October 2015   by www.ncbi.nlm.nih.gov    
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    
MRI Resources 
Pediatric and Fetal MRI - Diffusion Weighted Imaging - Pacemaker - Brain MRI - MRA - MRI Accidents
 
Lumbar Spine MRI
 
MRI of the lumbar spine, with its multiplanar 3 dimensional imaging capability, is currently the preferred modality for establishing a diagnosis. MRI scans and magnetic resonance myelography have many advantages compared with computed tomography and/or X-ray myelography in evaluating the lumbar spine. MR imaging scans large areas of the spine without ionizing radiation, is noninvasive, not affected by bone artifacts, provides vascular imaging capability, and makes use of safer contrast agents (gadolinium chelate).
Due to the high level of tissue contrast resolution, nerves and discs are clearly visible. MRI is excellent for detecting degenerative disease in the spine. Lumbar spine MRI accurately shows disc disease (prolapsed disc or slipped disc), the level at which disc disease occurs, and if a disc is compressing spinal nerves. Lumbar spine MRI depicts soft tissues, including the cauda equina, spinal cord, ligaments, epidural fat, subarachnoid space, and intervertebral discs. Loss of epidural fat on T1 weighted images, loss of cerebrospinal fluid signal around the dural sac on T2 weighted images and degenerative disc disease are common features of lumbar stenosis.

Common indications for MRI of the lumbar spine:
Neurologic deficits, evidence of radiculopathy, acute spinal cord compression (e.g., sudden bowel/bladder disturbance)
Suspected systemic disorders (primary tumors, drop metastases, osteomyelitis)
Postoperative evaluation of lumbar spine: disk vs. scar
Localized back pain with no radiculopathy (leg pain)

Lumbar spine imaging requires a special spine coil. often used whole spine array coils have the advantage that patients do not need other positioning if also upper parts of the spine should be scanned. Sagittal T1 and T2 weighted FSE sequences are the standard views. With multi angle oblique techniques individually oriented transverse images of each intervertebral disc at different angles can be obtained.

See also the related poll result: 'MRI will have replaced 50% of x-ray exams by'
 
Images, Movies, Sliders:
 Anatomic Imaging of the Lumbar Spine  Open this link in a new window
      

Courtesy of  Robert R. Edelman

 
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• View the DATABASE results for 'Lumbar Spine MRI' (6).Open this link in a new window

 
Further Reading:
  Basics:
Lumbar Spine Stenosis: A Common Cause of Back and Leg Pain
   by www.aafp.org    
Spine imaging after lumbar disc replacement: pitfalls and current recommendations
Tuesday, 21 July 2009   by 7thspace.com    
  News & More:
Impact of patient-reported symptom information on lumbar spine MRI Interpretation
Monday, 25 January 2021   by www.eurekalert.org    
Lumbar spine MRI reports are too difficult for patients to understand
Friday, 29 March 2019   by www.eurekalert.org    
Inappropriate Ordering of Lumbar Spine Magnetic Resonance Imaging: Are Providers Choosing Wisely? -
Tuesday, 2 February 2016   by www.ajmc.com    
How Weight-Bearing MRIs Can Improve Care & Lower Costs While Meeting Milliman Criteria
Friday, 4 October 2013   by www.beckersspine.com    
Lumbar Diskal Cyst Containing Intervertebral Disk Materials
Tuesday, 1 November 2011   by www.orthosupersite.com    
A Study of the Morphology of Lumbar Discs in Sitting and Standing Positions Using a 0.5T Open- Configuration MRI(.pdf)
2001   by cds.ismrm.org    
Searchterm 't2' was also found in the following services: 
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News  (28)  Resources  (5)  Forum  (67)  
 
Magic Angle Effect (Artifact)InfoSheet: - Artifacts - 
Case Studies, 
Reduction Index, 
etc.MRI Resource Directory:
 - Artifacts -
 
Quick Overview
Artifact Information
NAME
Magic angle
DESCRIPTION
Increase of the T2 time, bright signal in tendons
REASON
Angle about 55° to the main magnetic field
HELP
Angle not about 55°
The magic angle is a precisely defined angle, the value is approximately 54.7°. Hence, two nuclei with a dipolar coupling vector at an angle of approximately 54.7° to a strong external magnetic field have zero dipolar coupling.
Magic angle spinning is a technique in solid-state NMR spectroscopy, which employs this principle to remove or reduce dipolar couplings, thereby increasing spectral resolution. In MRI, the magic angle effect visualizes as bright spots through an increased T2 time on short echo time (TE) images, for e.g. collagen fibers of tendons and ligaments, which are oriented at the magic angle of approximately 54.7° to the magnetic field.
mri safety guidance
Image Guidance
Take care that tendons and ligaments are not oriented at about a 54.7° angle to the main magnetic field.
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Further Reading:
  Basics:
Magic angle
   by en.wikipedia.org    
Magic Angle Effects
   by www.mritutor.org    
MRI Resources 
Liver Imaging - Patient Information - Societies - MRI Centers - Research Labs - Jobs
 
Magnetic Resonance CholangiopancreaticographyMRI Resource Directory:
 - MRCP -
 
(MRCP) This MR imaging technique takes advantage of the high signal intensity of body fluids and acquires heavy T2 weighted images of the gall bladder, the pancreas and parts of the liver. Due to the T2 weighting, the liver and other solid parenchyma are signal suppressed and only fluid-filled structures in addition to the gall bladder, the bile and pancreatic ducts retain important signal intensity. Hepatobiliary contrast agents (e.g. Gadoxetic Acid, CMC 001) can be useful for enhancement of the bile ducts and better imaging of the biliary tract.
A 2D cholangiogram, often only one thick slice (a volume with a thickness of 4 - 8 cm, mostly coronal planned) or 5 - 6 radial placed slices, shows a view like single slices. If a 3D acquisition is used, the postprocessing function maximum intensity projection (MIP) can show reconstructions from multiple sides.
Radiology-tip.comradBiliary Contrast Agents
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Medical-Ultrasound-Imaging.comGallbladder Ultrasound
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• View the DATABASE results for 'Magnetic Resonance Cholangiopancreaticography' (3).Open this link in a new window

 
Further Reading:
  News & More:
Perspectum and Nuance Collaborate to Scale Access to AI-Enabled Integrated Digital Care Platforms to Improve Patient Care for Metabolic Disease
Friday, 9 December 2022   by www.itnonline.com    
MRI Resources 
Shoulder MRI - MR Guided Interventions - Diffusion Weighted Imaging - Coils - Bioinformatics - Mobile MRI Rental
 
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