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Result : Searchterm 'Pulse Sequence' found in 5 terms [] and 166 definitions []
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Searchterm 'Pulse Sequence' was also found in the following services: 
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News  (2)  Resources  (5)  Forum  (10)  
 
Interpulse Times
 
(T) Times between successive RF pulses used in pulse sequences. Particularly important are the inversion time (TI) in inversion recovery, and the time between 90° pulse and the subsequent 180° pulse to produce a spin echo, which will be approximately one half the spin echo time(TE). The time between repetitions of pulse sequences is the repetition time(TR).
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Ultrasound  (1) Open this link in a new window
Knee MRI
 
Knee MRI, with its high soft tissue contrast is one of the main imaging tools to depict knee joint pathology. MRI allows accurate imaging of intra-articular structures such as ligaments, cartilage, menisci, bone marrow, synovium, and adjacent soft tissue.
Knee exams require a dedicated extremity coil, providing a homogenous imaging volume and high SNR to ensure best signal coverage. A complete knee MR examination includes for example sagittal and coronal T1 weighted, and proton density weighted pulse sequences +/- fat saturation, or STIR sequences. For high spatial resolution, maximal 4 mm thick slices with at least an in plane resolution of 0.75 mm and small gap are recommended. To depict the anterior cruciate ligament clearly, the sagittal plane has to be rotated 10 - 20° externally (parallel to the medial border of the femoral condyle). Retropatellar cartilage can bee seen for example in axial T2 weighted gradient echo sequences with Fatsat. However, the choice of the pulse sequences is depended of the diagnostic question, the used scanner, and preference of the operator.
Diagnostic quality in knee imaging is possible with field strengths ranging from 0.2 to 3T. With low field strengths more signal averages must be measured, resulting in increased scan times to provide equivalent quality as high field strengths.
More diagnostic information of meniscal tears and chondral defects can be obtained by direct magnetic resonance arthrography, which is done by introducing a dilute solution of gadolinium in saline (1:1000) into the joint capsule. The knee is then scanned in all three planes using T1W sequences with fat suppression. For indirect arthrography, the contrast is given i.v. and similar scans are started 20 min. after injection and exercise of the knee.
Frequent indications of MRI scans in musculoskeletal knee diseases are:
e.g., meniscal degeneration and tears, ligament injuries, osteochondral fractures, osteochondritis dissecans, avascular bone necrosis and rheumatoid arthritis.

See also Imaging of the Extremities and STIR.
 
Images, Movies, Sliders:
 Sagittal Knee MRI Images T1 Weighted  Open this link in a new window
      

 Anatomic MRI of the Knee 2  Open this link in a new window
    
SlidersSliders Overview

 Knee MRI Coronal Pd Spir 001  Open this link in a new window
 Sagittal Knee MRI Images STIR  Open this link in a new window
      

 Axial Knee MRI Images T2 Weighted  Open this link in a new window
 Anatomic MRI of the Knee 1  Open this link in a new window
    
SlidersSliders Overview

 
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• View the DATABASE results for 'Knee MRI' (4).Open this link in a new window


• View the NEWS results for 'Knee MRI' (4).Open this link in a new window.
 
Further Reading:
  Basics:
Musculoskeletal MRI at 3.0 T: Relaxation Times and Image Contrast
Sunday, 1 August 2004   by www.ajronline.org    
Knee, Anterior Cruciate Ligament Injuries (MRI)
Tuesday, 28 March 2006   by www.emedicine.com    
  News & More:
NSAIDs May Worsen Arthritis Inflammation
Monday, 21 November 2022   by www.itnonline.com    
A Knee MRI in Half the Time? It's Possible
Thursday, 8 April 2021   by www.diagnosticimaging.com    
Seniors, patients, astronauts will all benefit from new USask research on bone health
Saturday, 27 February 2021   by www.yorktonthisweek.com    
3D mapping algorithm reads knee MRIs for new arthritis treatments
Thursday, 11 June 2020   by www.healthimaging.com    
MRI T2 Mapping of the Knee Providing Synthetic Morphologic Images: Comparison to Conventional Turbo Spin-Echo MRI
Tuesday, 1 October 2019   by pubs.rsna.org    
Researcher uses MRI to measure joint's geometry and role in severe knee injury
Tuesday, 23 September 2014   by medicalxpress.com    
Abnormalities on MRI predict knee replacement
Monday, 9 March 2015   by medicalxpress.com    
MRI Resources 
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MAGNETOM Allegraâ„¢InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.med.siemens.com/med/d/gg/mr/products/allegra.htm From Siemens Medical Systems;
the 3 T MAGNETOM Allegra is a dedicated MR headscanner, perfect as a research system in cognitive and neuroscience with MRS and fMRI. MAGNETOM Allegra is a full member of the MAGNETOM product family. It uses many common components, i.e. electronics, computer system, software and pulse sequence concepts.
Device Information and Specification
CLINICAL APPLICATION
CONFIGURATION
Short bore
Yes/Mutli-nuclear MRS
PULSE SEQUENCES
GRE, IR, FIR, STIR, TrueIR/FISP, FSE, FLAIR, MT, SS-FSE, MT-SE, MTC, MSE, EPI, GMR, fat/water sat./exc.
IMAGING MODES
Single, multislice, volume study, multi angle, multi oblique
SINGLE/MULTI SLICE
178 images/sec at 256 x 256 at 100% FOV
FOV
22 cm
Min 2D/3D: 0.1/0.05 mm
1024 x 1024 full screen display
MEASURING MATRIX
64 x 64 to 1024 x 1024
10 micrometer
BORE DIAMETER
or W x H
60 x 60 cm
MAGNET WEIGHT (gantry included)
5500 kg
DIMENSION H*W*D (gantry included)
220 x 220 x 147 cm
POWER REQUIREMENTS
380/400/420/440/480 V
COOLING SYSTEM TYPE
Single cryogen, 2 stage refrig.
CRYOGEN USE
0.1 L/hr helium
STRENGTH
40 mT/m
Passive, act.; 1st order std./2nd opt.
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Searchterm 'Pulse Sequence' was also found in the following services: 
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News  (2)  Resources  (5)  Forum  (10)  
 
Magnetic Field Mapping
 
The mapping of the magnetic field by measuring or imaging the spatial distribution of magnetic field strength, can be performed by scanning with a probe and handles a large range of field strengths, but is slow and tedious. Accurate field maps can be made by measuring the Larmor frequency as a function of position.
The field must be homogeneous enough to allow MR imaging to be performed, than the magnetic field can be mapped by different methods.
1. The adaptation of chemical shift imaging.
2. The faster one measures the change in signal phase in an image obtained with a gradient echo pulse sequence resulting from a change in echo time TE, which is proportional to the local field strength.
Also useful is a spin echo pulse sequence with data collection from two time locations of the readout gradient and the data acquisition interval, where each having a known shift of the acquisition center away from the spin echo.
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Further Reading:
  News & More:
sPHENIX assembly update: magnet mapped, detectors prepared
Friday, 23 December 2022   by www.eurekalert.org    
Searchterm 'Pulse Sequence' was also found in the following service: 
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Ultrasound  (1) Open this link in a new window
Magnetic Resonance MyelographyMRI Resource Directory:
 - MR Myelography -
 
MR myelography is studying the spinal canal and subarachnoid space by high-resolution MRI with a technique in which a sequence with strong T2 weighting is used to provide high contrast between the "dark" spinal cord and its nerves and the surrounding "bright" cerebrospinal fluid. MR myelography as part of an entire MR examination has virtually replaced X-ray myelography. Used sequences are T2 weighted fast spin echo pulse sequences or a refocused gradient echo pulse sequence with strong T2 weighting.

See also the related poll result: 'MRI will have replaced 50% of x-ray exams by'
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MRI Resources 
Abdominal Imaging - Nerve Stimulator - Spectroscopy pool - Most Wanted - IR - MR Myelography
 
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