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 'T2 Weighted' 
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Result : Searchterm 'T2 Weighted' found in 2 terms [] and 44 definitions []
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Searchterm 'T2 Weighted' was also found in the following services: 
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Spin Echo SequenceInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.MRI Resource Directory:
 - Sequences -
 
Spin Echo Timing Diagram (SE) The most common pulse sequence used in MR imaging is based of the detection of a spin or Hahn echo. It uses 90° radio frequency pulses to excite the magnetization and one or more 180° pulses to refocus the spins to generate signal echoes named spin echoes (SE).
In the pulse sequence timing diagram, the simplest form of a spin echo sequence is illustrated.
The 90° excitation pulse rotates the longitudinal magnetization (Mz) into the xy-plane and the dephasing of the transverse magnetization (Mxy) starts.
The following application of a 180° refocusing pulse (rotates the magnetization in the x-plane) generates signal echoes. The purpose of the 180° pulse is to rephase the spins, causing them to regain coherence and thereby to recover transverse magnetization, producing a spin echo.
The recovery of the z-magnetization occurs with the T1 relaxation time and typically at a much slower rate than the T2-decay, because in general T1 is greater than T2 for living tissues and is in the range of 100–2000 ms.
The SE pulse sequence was devised in the early days of NMR days by Carr and Purcell and exists now in many forms: the multi echo pulse sequence using single or multislice acquisition, the fast spin echo (FSE/TSE) pulse sequence, echo planar imaging (EPI) pulse sequence and the gradient and spin echo (GRASE) pulse sequence;; all are basically spin echo sequences.
In the simplest form of SE imaging, the pulse sequence has to be repeated as many times as the image has lines.
Contrast values:
PD weighted: Short TE (20 ms) and long TR.
T1 weighted: Short TE (10-20 ms) and short TR (300-600 ms)
T2 weighted: Long TE (greater than 60 ms) and long TR (greater than 1600 ms)
With spin echo imaging no T2* occurs, caused by the 180° refocusing pulse. For this reason, spin echo sequences are more robust against e.g., susceptibility artifacts than gradient echo sequences.
See also Pulse Sequence Timing Diagram to find a description of the components.
 
Images, Movies, Sliders:
 Shoulder Coronal T1 SE  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 Shoulder Axial T1 SE  Open this link in a new window
 MRI Orbita T1  Open this link in a new window
    
 
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• Related Searches:
    • Echo Time
    • Lumbar Spine MRI
    • T2 Weighted
    • T1 Time
    • Brain MRI
 
Further Reading:
  Basics:
Fast Spin Echo(.pdf)
Tuesday, 24 January 2006   by www.81bones.net    
Magnetic resonance imaging
   by www.scholarpedia.org    
FUNDAMENTALS OF MRI: Part I
   by www.e-radiography.net    
  News & More:
New MR sequence helps radiologists more accurately evaluate abnormalities of the uterus and ovaries
Thursday, 23 April 2009   by www.eurekalert.org    
MRI techniques improve pulmonary embolism detection
Monday, 19 March 2012   by medicalxpress.com    
MRI Resources 
Non-English - Education pool - Lung Imaging - Pregnancy - Jobs - Abdominal Imaging
 
Spine MRIMRI Resource Directory:
 - Spine MRI -
 
Magnetic resonance imaging (MRI) of the spine is a noninvasive procedure to evaluate different types of tissue, including the spinal cord, vertebral disks and spaces between the vertebrae through which the nerves travel, as well as distinguish healthy tissue from diseased tissue.
The cervical, thoracic and lumbar spine MRI should be scanned in individual sections. The scan protocol parameter like e.g. the field of view (FOV), slice thickness and matrix are usually different for cervical, thoracic and lumbar spine MRI, but the method is similar. The standard views in the basic spinal MRI scan to create detailed slices (cross sections) are sagittal T1 weighted and T2 weighted images over the whole body part, and transverse (e.g. multi angle oblique) over the region of interest with different pulse sequences according to the result of the sagittal slices. Additional views or different types of pulse sequences like fat suppression, fluid attenuation inversion recovery (FLAIR) or diffusion weighted imaging are created dependent on the indication.
Indications:
Neurological deficit, evidence of radiculopathy, cauda equina compression
Primary tumors or drop metastases
Infection/inflammatory disease, multiple sclerosis
Postoperative evaluation of lumbar spine: disk vs. scar
Evaluation of syrinx
Localized back pain with no radiculopathy (leg pain)

Contrast enhanced MRI techniques delineate infections vs. malignancies, show a syrinx cavity and support to differentiate the postoperative conditions. After surgery for disk disease, significant fibrosis can occur in the spine. This scarring can mimic residual disk herniation. Magnetic resonance myelography evaluates spinal stenosis and various intervertebral discs can be imaged with multi angle oblique techniques. Cine series can be used to show true range of motion studies of parts of the spine. Advanced open MRI devices are developed to perform positional scans in the position of pain or symptom (e.g. Upright™ MRI formerly Stand-Up MRI).
 
Images, Movies, Sliders:
 Anatomic Imaging of the Lumbar Spine  Open this link in a new window
      

Courtesy of  Robert R. Edelman

 
Radiology-tip.comBone Densitometry,  Myelography
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• View the DATABASE results for 'Spine MRI' (11).Open this link in a new window


• View the NEWS results for 'Spine MRI' (4).Open this link in a new window.
 
Further Reading:
  Basics:
Newer Sequences for Spinal MR Imaging: Smorgasbord or Succotash of Acronyms?
   by www.ajnr.org    
Cutting Edge Imaging of THE Spine
February 2007   by www.pubmedcentral.nih.gov    
Landmark Independent Study by UCLA School of Medicine Reports Comparison of Dynamic™ Upright® MRI With Static Upright MRI in More Than 1,000 Patients (1,302):
Thursday, 15 November 2007   by www.fonar.com    
  News & More:
Discriminating imaging findings of acute osteoporotic vertebral fracture: a prospective multicenter cohort study
Thursday, 9 October 2014   by 7thspace.com    
Lumbar spine MRI limited in diagnosing ankylosing spondylitis
Friday, 7 March 2014   by www.healio.com    
MRI Of The Spine Identifies Smoldering Myeloma Patients At High Risk Of Progressing To Multiple Myeloma
Tuesday, 26 August 2014   by www.myelomabeacon.com    
Intensive training of young tennis players causes spinal damage
Wednesday, 18 July 2007   by www.eurekalert.org    
Imaging Technique for Spinal Cord Injury Shows Promise
Sunday, 22 December 2013   by www.wauwatosanow.com    
MRI Resources 
Brain MRI - Knee MRI - Lung Imaging - Manufacturers - Safety pool - Absorption and Emission
 
Steady State Free PrecessionInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.MRI Resource Directory:
 - Sequences -
 
(SFP or SSFP) Steady state free precession is any field or gradient echo sequence in which a non-zero steady state develops for both components of magnetization (transverse and longitudinal) and also a condition where the TR is shorter than the T1 and T2 times of the tissue. If the RF pulses are close enough together, the MR signal will never completely decay, implying that the spins in the transverse plane never completely dephase. The flip angle and the TR maintain the steady state. The flip angle should be 60-90° if the TR is 100 ms, if the TR is less than 100 ms, then the flip angle for steady state should be 45-60°.
Steady state free precession is also a method of MR excitation in which strings of RF pulses are applied rapidly and repeatedly with interpulse intervals short compared to both T1 and T2. Alternating the phases of the RF pulses by 180° can be useful. The signal reforms as an echo immediately before each RF pulse;; immediately after the RF pulse there is additional signal from the FID produced by the pulse.
The strength of the FID will depend on the time between pulses (TR), the tissue and the flip angle of the pulse; the strength of the echo will additionally depend on the T2 of the tissue. With the use of appropriate dephasing gradients, the signal can be observed as a frequency-encoded gradient echo either shortly before the RF pulse or after it; the signal immediately before the RF pulse will be more highly T2 weighted. The signal immediately after the RF pulse (in a rapid series of RF pulses) will depend on T2 as well as T1, unless measures are taken to destroy signal refocusing and prevent the development of steady state free precession.
To avoid setting up a state of SSFP when using rapidly repeated excitation RF pulses, it may be necessary to spoil the phase coherence between excitations, e.g. with varying phase shifts or timing of the exciting RF pulses or varying spoiler gradient pulses between the excitations.
Steady state free precession imaging methods are quite sensitive to the resonant frequency of the material. Fluctuating equilibrium MR (see also FIESTA and DRIVE)and linear combination SSFP actually use this sensitivity for fat suppression. Fat saturated SSFP (FS-SSFP) use a more complex fat suppression scheme than FEMR or LCSSFP, but has a 40% lower scan time.
A new family of steady state free precession sequences use a balanced gradient, a gradient waveform, which will act on any stationary spin on resonance between 2 consecutive RF pulses and return it to the same phase it had before the gradients were applied.
This sequences include, e.g. Balanced Fast Field Echo - bFFE, Balanced Turbo Field Echo - bTFE, Fast Imaging with Steady Precession - TrueFISP and Balanced SARGE - BASG. See also FIESTA.
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• View the DATABASE results for 'Steady State Free Precession' (20).Open this link in a new window

 
Further Reading:
  News & More:
Comparison of New Methods for Magnetic Resonance Imaging of Articular Cartilage(.pdf)
2002
Searchterm 'T2 Weighted' was also found in the following services: 
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News  (7)  Resources  (1)  Forum  (6)  
 
T1 TimeForum -
related threads
 
The T1 relaxation time (also called spin lattice or longitudinal relaxation time), is a biological parameter that is used in MRIs to distinguish between tissue types. This tissue-specific time constant for protons, is a measure of the time taken to realign with the external magnetic field. The T1 constant will indicate how quickly the spinning nuclei will emit their absorbed RF into the surrounding tissue.
As the high-energy nuclei relax and realign, they emit energy which is recorded to provide information about their environment. The realignment with the magnetic field is termed longitudinal relaxation and the time in milliseconds required for a certain percentage of the tissue nuclei to realign is termed 'Time 1' or T1. Starting from zero magnetization in the z direction, the z magnetization will grow after excitation from zero to a value of about 63% of its final value in a time of T1. This is the basic of T1 weighted images.
The T1 time is a contrast determining tissue parameter. Due to the slow molecular motion of fat nuclei, longitudinal relaxation occurs rather rapidly and longitudinal magnetization is regained quickly. The net magnetic vector realigns with B0 leading to a short T1 time for fat.
Water is not as efficient as fat in T1 recovery due to the high mobility of the water molecules. Water nuclei do not give up their energy to the lattice (surrounding tissue) as quickly as fat, and therefore take longer to regain longitudinal magnetization, resulting in a long T1 time.
See also T1 Weighted Image, T1 Relaxation, T2 Weighted Image, and Magnetic Resonance Imaging MRI.
 
Images, Movies, Sliders:
 Anatomic MRI of the Knee 2  Open this link in a new window
    
SlidersSliders Overview

 Breast MRI Images T2 And T1  Open this link in a new window
 Brain MRI Images T1  Open this link in a new window
      

 
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• View the DATABASE results for 'T1 Time' (15).Open this link in a new window

 
Further Reading:
  Basics:
IMAGE CONTRAST IN MRI(.pdf)
   by www.assaftal.com    
Magnetic resonance imaging - From Wikipedia, the free encyclopedia.
   by en.wikipedia.org    
  News & More:
New technique could allow for safer, more accurate heart scans
Thursday, 10 December 2015   by www.gizmag.com    
Rockland Technimed: Tissue Viability Imaging
Saturday, 15 December 2007   by www.onemedplace.com    
MRI Resources 
Nerve Stimulator - MRI Training Courses - Absorption and Emission - Non-English - Lung Imaging - Hospitals
 
Teslascan®InfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
(Mn-DPDP) This agent, mangafodipir trisodium, is a hepatocyte specific MRI contrast agent. Manganese is very toxic, so it has to be chelated and put in the form of a vitamin B6 analog, which is taken up by normal hepatocytes to some extent.
Teslascan® was developed in the early 1980's, went through clinical trials in the early 1990's, and was approved in 1997. One problem with assessing the efficacy of this agent is the fact that the phase III trials finished in the early 1990's, and the techniques used for MR today are very different from the techniques used almost a decade ago.
This contrast agent shortens the T1 relaxation time. On T1 weighted pictures it makes a normal liver look brighter. Since metastases, for example, do not generally take up this agent, the contrast between the enhancing liver and the non-enhancing lesions will increase on T1 weighted pictures. It does not have much effect on T2 weighted images.

Drug Information and Specification
NAME OF COMPOUND Mangafodipir trisodium, Manganese dipyroxyl diphosphate, MN-DPDP
DEVELOPER Amersham plc
CENTRAL MOIETY Mn2+
CONTRAST EFFECT T1, Predominantly positive enhancement
RELAXIVITY r1=2.3, r2=4.0, B0=1.0 T
PHARMACOKINETIC Hepatobiliary, pancreatic, adrenal
OSMOLALITY 290 mosm/kgH2O
CONCENTRATION 0.01 mmol/L
DOSAGE 5 µmol/kg, 0.5 ml/kg
PREPARATION Finished product
INDICATION Liver lesions
DEVELOPMENT STAGE Approved
DISTRIBUTOR See below
PRESENTATION Vials of 100 ml
DO NOT RELY ON THE INFORMATION PROVIDED HERE, THEY ARE NOT A SUBSTITUTE FOR THE ACCOMPANYING PACKAGE INSERT!

Distribution Information
TERRITORY TRADE NAME DEVELOPMENT
STAGE
DISTRIBUTOR
USA Teslascan® for sale GE Healthcare
EU Teslascan® for sale GE Healthcare

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

 
Further Reading:
  Basics:
EMEA - Teslascan - SCIENTIFIC DISCUSSION(.pdf)
   by www.emea.europa.eu    
  News & More:
Diagnosis and staging of pancreatic cancer: comparison of mangafodipir trisodium-enhanced MR imaging and contrast-enhanced helical hydro-CT.
2002
MAGNETIC RESONANCE IMAGING OF FOCAL LIVER LESIONS(.pdf)
2002
MRI Resources 
Shoulder MRI - NMR - Functional MRI - Libraries - Journals - Fluorescence
 
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