We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.
Nobody downloaded yet

BLIP Echo Planar Imaging Method - Essay Example

Comments (0) Cite this document
Summary
Q1. BLIP Echo Planar Imaging (EPI) method- Principles of EPI: EPI, like FSE (Fast Spin Echo), is an imaging method that reduces the imaging time as it acquires multiple phase encoding steps in each repetition time (TR). It is a fast and flexible method of imaging that provides with good contrast and resolution for the images…
Download full paperFile format: .doc, available for editing
Polish This Essay96.9% of users find it useful
BLIP Echo Planar Imaging Method
Read TextPreview

Extract of sample
"BLIP Echo Planar Imaging Method"

Download file to see previous pages Sampling of k-space is different in EPI that enables high quality of images acquired. EPI uses quickly switching gradients to produce its echo train as against use of RF pulses in FSE. EPI frequency encoding gradient oscillates from positive to negative to create odd and even echoes. Each read gradient echo corresponds to one k-space with the positive and negative gradients changing the direction of the line that is read. The changing of direction of the line read results in a phase ‘blip’ causing a shift in Ky and this method of phase encoding is referred to as blip EPI. Characteristics of EPI: EPI has three distinct characteristics in terms of speed, the variety of contrast and the flexibility in terms of available resolution for imaging small structures like the pituitary gland. EPI offers higher speeds (6 to 10 times) of imaging of short temporal events under motion. It provides with high image quality by collecting more averages with increased slice frequency per TR. The signal to noise ratio of the images is high and the resolution is also high. Its usefulness depends on the MR system used and the efficiency is determined by the ability to perform 1282 or 2562 in a very short time to avoid large off resonance artifacts. It means that high quality images of moving patients can be obtained by using the speed of EPI. A variety of tissue contrasts (T1, T2 and T2*) are allowed by EPI for image acquisition and small structures are imaged using the flexibility in resolution where the field view can be reduced, the echo train length can be increased or geometric distortions can be reduced to increase the resolution. Also, just half of the data of the image can be gathered that can be further synthesized through conjugation to obtain the remaining data. Flexibility in contrast can be used to produce an image similar in standards to that of an SE image with the same TE and TR by using an excitation pulse in the front part followed by a 1800 pulse (T2* dephasing) to create the first echo. EPI compared to conventional fast imaging methods: EPI uses the Blip EP method of phase encoding where each phase blip between echoes causes a shift in k-space line. Each k-space line is contributed by the gradient refocused echo and is either read positively or negatively through the gradient change. The quickly switching gradients that produce the echo train are responsible for the odd and even echoes. When the lines are read, the reversed read lines are reordered before constructing the image. Also, the rf pulse is not used to create multiple echoes as in conventional FSE. Figure 1: (a) Pulse diagram of FSE, 4 echoes and (b) pulse diagram of EPI. Source: (McMahan, 2012). Benefits in EPI: Acquiring single snap shot images is much faster (20-100 ms) using EPI when compared to conventional FSE as gradient echoes take less time as all the encoding steps are obtained after one single excitation pulse is applied. This is in contrast to the train of rf pulses applied that increases TR. Also, EPI allows flexibility in contrast that enables even small structures to be imaged very fast. Further, slice coverage is increased with EPI when compared to FSE. EPI has fewer rf pulses that result in low specific absorption rate (SAR). As SAR is low, TR is also low, resulting in more slices to be covered in the same TR as in FSE. Sensitivity to resonance effects: A disadvantage in EPI is that it is sensitive to off resonance effects of the echo gradients ...Download file to see next pagesRead More
Cite this document
  • APA
  • MLA
  • CHICAGO
(“BLIP Echo Planar Imaging Method Essay Example | Topics and Well Written Essays - 2500 words”, n.d.)
Retrieved de https://studentshare.org/physics/1445011-mres
(BLIP Echo Planar Imaging Method Essay Example | Topics and Well Written Essays - 2500 Words)
https://studentshare.org/physics/1445011-mres.
“BLIP Echo Planar Imaging Method Essay Example | Topics and Well Written Essays - 2500 Words”, n.d. https://studentshare.org/physics/1445011-mres.
  • Cited: 0 times
Comments (0)
Click to create a comment or rate a document
CHECK THESE SAMPLES - THEY ALSO FIT YOUR TOPIC
Echo Planar Imaging, or EPI, Fast Imaging Techniques (MRI)
EPI is a fast, flexible imaging method, with good contrast and resolution, and with many potential applications in clinical imaging, such as functional MRI and rapid entire brain imaging. Though, EPI can be very unforgiving and requires careful parameter selection (Weishaupt, Koechli and Marincek, 2008).
15 Pages(3750 words)Essay
EPI7005_2
Water proton amounts found in the inhomogeneity of the local field will result in off-resonance. The frequency changes of such spins vary in different regions and in different patients. However, its behavior will still resemble that of off-resonance fat. Several methods have been used in the correction of geometric distortions in MRI diffusion weighted normally resulting from static magnetic field inhomogeneties.
10 Pages(2500 words)Essay
Echo Planar Imaging, or EPI, Fast Imaging Techniques (MRI)
Introduction Magnetic susceptibility refers to the process y issue tissue affects magnetic field. The existing boundaries between fat and compact bone are normally affected by the transverse magnetic field de-phasing and signal distortion. The consequent of the above is that frequency positions in the wrong location in the phase direction.
10 Pages(2500 words)Essay
Echo cancellation and applications
Their scope lies in the full duplex data transmission over wire to wire circuits. Echo is observed in telecommunications. Certain filter structures are used including FIR, IIR, lattice structure, frequency domain structure, memory type structure, among which FIR is of most use.
7 Pages(1750 words)Essay
Echo-planar Imaging in Magnetic Resonance Imaging
“EPI is fundamentally just a trick of spatial encoding” (Cohen, 2000, p.3). EPI is a speedy, elastic method of imaging. It has high-quality contrast and resolution capabilities, and also possesses many prospective applications in clinical imaging, including functional MRI and rapid whole brain imaging.
8 Pages(2000 words)Essay
Fast Imaging Techniques (MRI)
Receiver bandwidth is generally used to fasten the digitalisation of the MR signals. In this regard, the receiver bandwidth 1 can determine the frequency ranges that will eventually be sampled using the frequency encoding gradient. During the optimization through an increase of receiver bandwidth, the amount of time at the flat top of the gradient is significantly reduced.
6 Pages(1500 words)Essay
Planar Ultra Wideband Antenna for Microwave Imaging System for Medical Application (Project Debrief)
Furthermore, It is a fact that effective Work Integrated Learning (WIL) programs offers numerous benefits to all the stakeholders (employers, students and university). As a student, I appreciate Griffith University’s Industry
5 Pages(1250 words)Essay
Imaging
2). As the air is inspired, it travels from the trachea which represents the trunk of the tree, and continues to its smaller branches in the form of the bronchi and bronchioles until it
6 Pages(1500 words)Essay
Madonnas Of Echo Park
Most importantly, the author is trying to illustrate the essence of Americanization as a form of success as well as being accepted by the society. The characters that appeared in the novel show the
2 Pages(500 words)Essay
METHOD
These students will participate in the experimental study to assess the impact of online classes and traditional classes. The participants will be informed that the experiment will measure how they captured concepts of the materials used in the class. The
4 Pages(1000 words)Essay
Let us find you another Essay on topic BLIP Echo Planar Imaging Method for FREE!
Contact us:
+16312120006
Contact Us Now
FREE Mobile Apps:
  • About StudentShare
  • Testimonials
  • FAQ
  • Blog
  • Free Essays
  • New Essays
  • Essays
  • The Newest Essay Topics
  • Index samples by all dates
Join us:
Contact Us