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News  (18)  Resources  (5)  Forum  (54)  
 
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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• Related Searches:
    • MRI History
    • Magnetic Resonance Myelography
    • Crosstalk (Artifact)
    • Contrast Agents
    • Cervical Spine MRI
 
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    
MRI Resources 
Absorption and Emission - Directories - Process Analysis - Software - Spine MRI - Collections
 
MAGNETOM Skyra
 
www.healthcare.siemens.com/magnetic-resonance-imaging/0-35-to-1-5t-mri-scanner/magnetom-skyra/ From Siemens Medical Systems; Received FDA clearance in 2010.
MAGNETOM Skyra is a top-of-the-line, patient friendly wide bore 3 Tesla MRI system.
The system is equipped with the Tim 4G and Dot system (Total imaging matrix and Day optimizing throughput), to enhance both productivity and image quality with the complete range of advanced applications for clinical routine and research. Tim 4G features lighter, trimmer MRI coils that take up less space inside the magnet but deliver a high coil element density with increased signal to noise ratio and the possibility to use high iPAT factors.
Device Information and Specification
CLINICAL APPLICATION
Whole Body
CONFIGURATION
Open bore
3 Tesla
Head, spine, torso/ body coil, neurovascular, cardiac, neck, shoulder, knee, wrist, foot//ankle and multi-purpose flex coils. Peripheral vascular, breast, shoulder.
CHANNELS (min. / max. configuration)
48, 64, 128
Chemical shift imaging, single voxel spectroscopy
IMAGING TECHNIQUES
iPAT, mSENSE and GRAPPA (image, k-space),CAIPIRINHA (k-space), noncontrast angiography, plaque imaging, radial motion compensation, Dixon
MINIMUM TR
3D T1 spoiled GRE: 0.95 (256 matrix)
MINIMUM TE
3D T1 spoiled GRE: 0.22 (256 matrix), Ultra-short TE
FOV
0.5 - 50 cm
BORE DIAMETER
or W x H
At isocenter: L-R 70 cm, A-P (with table) 55 cm
TABLE CAPACITY
250 kg
MAGNET WEIGHT (gantry included)
5768 kg
DIMENSION H*W*D (gantry included)
173 x 231 x 219 cm
5-GAUSS FRINGE FIELD
2.6 m / 4.6 m
CRYOGEN USE
Zero boil off rate, approx. 10 years
COOLING SYSTEM
Water; single cryogen, 2 stage refrigeration
up to 200 T/m/s
MAX. AMPLITUDE
45 mT/m
3 linear with 20 coils, 5 nonlinear 2nd-order
POWER REQUIREMENTS
380 / 400 / 420 / 440 / 460 / 480 V, 3-phase + ground; 110 kVA
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MRI Resources 
Homepages - NMR - Cochlear Implant - Software - Brain MRI - Chemistry
 
Magnetic Resonance Angiography MRAMRI Resource Directory:
 - MRA -
 
(MRA) Magnetic resonance angiography is a medical imaging technique to visualize blood filled structures, including arteries, veins and the heart chambers. This MRI technique creates soft tissue contrast between blood vessels and surrounding tissues primarily created by flow, rather than displaying the vessel lumen. There are bright blood and black blood MRA techniques, named according to the appearance of the blood vessels. With this different MRA techniques both, the blood flow and the condition of the blood vessel walls can be seen. Flow effects in MRI can produce a range of artifacts. MRA takes advantage of these artifacts to create predictable image contrast due to the nature of flow.
Technical parameters of the MRA sequence greatly affect the sensitivity of the images to flow with different velocities or directions, turbulent flow and vessel size.
This are the three main types of MRA:
All angiographic techniques differentially enhance vascular MR signal. The names of the bright blood techniques TOF and PCA reflect the physical properties of flowing blood that were exploited to make the vessels appear bright. Contrast enhanced magnetic resonance angiography creates the angiographic effect by using an intravenously administered MR contrast agent to selectively shorten the T1 of blood and thereby cause the vessels to appear bright on T1 weighted images.
MRA images optimally display areas of constant blood flow-velocity, but there are many situations where the flow within a voxel has non-uniform speed or direction. In a diseased vessel these patterns are even more complex. Similar loss of streamline flow occurs at all vessel junctions and stenoses, and in regions of mural thrombosis. It results in a loss of signal, due to the loss of phase coherence between spins in the voxel.
This signal loss, usually only noticeable distal to a stenosis, used to be an obvious characteristic of MRA images. It is minimized by using small voxels and the shortest possible TE. Signal loss from disorganized flow is most noticeable in TOF imaging but also affects the PCA images.
Indications to perform a magnetic resonance angiography (MRA):
Detection of aneurysms and dissections
Evaluation of the vessel anatomy, including variants
Blockage by a blood clot or stenosis of the blood vessel caused by plaques (the buildup of fat and calcium deposits)

Conventional angiography or computerized tomography angiography (CT angiography) may be needed after MRA if a problem (such as an aneurysm) is present or if surgery is being considered.

See also Magnetic Resonance Imaging MRI.
 
Images, Movies, Sliders:
 CE-MRA of the Carotid Arteries Colored MIP  Open this link in a new window
    
SlidersSliders Overview

 CE MRA of the Aorta  Open this link in a new window
    
SlidersSliders Overview

 TOF-MRA Circle of Willis Inverted MIP  Open this link in a new window
    

 PCA-MRA 3D Brain Venography Colored MIP  Open this link in a new window
    

 Circle of Willis, Time of Flight, MIP  Open this link in a new window
    
SlidersSliders Overview

 
Radiology-tip.comradCT Angiography,  Angiogram
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Medical-Ultrasound-Imaging.comVascular Ultrasound,  Intravascular Ultrasound
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• View the DATABASE results for 'Magnetic Resonance Angiography MRA' (3).Open this link in a new window


• View the NEWS results for 'Magnetic Resonance Angiography MRA' (10).Open this link in a new window.
 
Further Reading:
  Basics:
Magnetic resonance angiography: current status and future directions
Wednesday, 9 March 2011   by www.jcmr-online.com    
MR–ANGIOGRAPHY(.pdf)
  News & More:
3-D-printed model of stenotic intracranial artery enables vessel-wall MRI standardization
Friday, 14 April 2017   by www.eurekalert.org    
Conventional MRI and MR Angiography of Stroke
2012   by www.mc.vanderbilt.edu    
MR Angiography Highly Accurate In Detecting Blocked Arteries
Thursday, 1 February 2007   by www.sciencedaily.com    
Searchterm 'T1' was also found in the following services: 
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Magnetization Prepared Rapid Gradient EchoInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
(MP-GRE / MPRAGE / MP-RAGE) A fast 3D gradient echo pulse sequence using a magnetization preparation pulse like TurboFLASH. Only one segment or partition of a 3D data record is obtained per inversion preparation pulse. After the acquisition, for all rows a delay time (TD) is used to prevent saturation effects.
MPRAGE is designed for rapid acquisition with T1 weighted dominance. Fast gradient echoes are characterized by their rapid sampling time, high signal intensity and image contrast while approaching steady state (the echo is collected during the time when tissues are experiencing T1 relaxation). The rapid speed of the acquisition makes it an excellent alternative to breath-hold abdominal imaging, neuro, dynamic bolus, MR angiography and cardiac imaging.

See Gradient Echo Sequence.
 
Images, Movies, Sliders:
 Brain MRI Sagittal T1 001  Open this link in a new window
    
 
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• View the DATABASE results for 'Magnetization Prepared Rapid Gradient Echo' (3).Open this link in a new window

MRI Resources 
Jobs - Jobs pool - Blood Flow Imaging - Libraries - Cochlear Implant - Online Books
 
MetallofullerenesInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.
 
The paramagnetic water-soluble metallofullerenes (Gd-fullerenols), which have strong T1 shortening effect, can be used as a novel core material of MRI contrast agents. Gadolinium endohedral metallofullerenes have been synthesized as polyhydroxyl forms (Gd@C82(OH)n, Gd-fullerenes) with the evaluation of their paramagnetic properties. The modification to the water-soluble forms is essential for the biomedical application of the metallofullerenes. The in vitro water proton relaxivity, R1 (the effect on 1/T1), of Gd-fullerenes is significantly higher (20-folds) than that of commercial MRI contrast agents - e.g. Gd-DTPA.
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• View the NEWS results for 'Metallofullerenes' (1).Open this link in a new window.
 
Further Reading:
  News & More:
A Single X-Ray Strike Is Enough to Destroy an Entire Molecule
Friday, 20 March 2020   by scitechdaily.com    
MRI Resources 
Safety Training - Process Analysis - Intraoperative MRI - Image Quality - Artifacts - Case Studies
 
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