Consequently, the shortened duration of flat top reduces both ESP and the geometric distortion of the image (Jezzard and Balaban, 1995, p.71). Another consequence of increasing the receiver bandwidth is faster imaging. Although increasing the receiver bandwidth allows faster imaging, it may also significantly reduce the SNR, and this often leads to more noise outside the spectrum (Parrish, 2000, p.927). For example, as the bandwidth range is gradually increased, the system may begin to sample more inherent noise together with the generated echo signal, thereby resulting in the fall of SNR. There are a number of ways that can generally be used to help recover the signals lost as a result of a wider bandwidth during the optimization of image. Some of the choices include acquisition of more signal averages and improving the receiver coil technology. The first option is, however, counter-productive because it may increase the amount of time needed to perform the overall scan while the second option if often preferred because it helps maintain the original objective of choosing EPI. Lastly, with regard to the required T2 weighted image, increasing the receiver bandwidth may reduce the effects of chemical shift artefacts on the image. According to Ra and Rim (1993, p.145), this is because higher receiver bandwidth results in a wide range of resonant frequencies on which the distortion is spread in order to cover a smaller pixel range and minimize the geometric distortion. 2. Discuss the advantages and disadvantages of using segmentation in EPI. Segmentation is a new concept that has significantly made it possible to use EPI on most of the conventional imaging systems where constraints related to signal to noise would have otherwise prevented EPI. Segmenting EPI is increasingly becoming more important to a number of its properties that ensure improved image quality as compared to the conventional single shot EPI. For example, one of the potential benefits of segmentation is that it allows EPI to be able to effectively run on the conventional systems where single short EPI can not be used. This is because segmentation ensures less stress is placed on the gradients as opposed to single short EPI and is therefore critically important in situations where by the available SNR and hardware makes it difficult to acquire all the necessary k-space data before the elimination of the MR signal by the traverse relaxation (McRobbie et al., 2003, p.75). Another important advantage of segmented EPI is that it helps reduce the magnetic susceptibility of various artefacts. This is because phase errors often have less time to build up when segmented EPI as compared to single shot EPI. The shortening of echo train length also allows segmented EPI to be less prone to the effects of artefact variations. Segmentation can also be used to help reduce imaging distortion and enable higher image resolution as compared to single shot EPI. The other key benefit of segmentation of EPI is the fact that it can be used to increase resolution. This is particularly attributed to the fact that segmented EPI have relatively short echo train length, thereby leading to increased spatial resolution. On the other hand, normal single shot EPI usually have lower spatial
Fast Imaging Techniques (MRI) Insert name (s) Course Fast Imaging Techniques (MRI) 1. Discuss the chain of consequences if you optimise the image by increasing the receiver bandwidth. When the image is optimised by increasing the receiver bandwidth, a number of sequences occur before the required field of view and matrix size of the T2 weighted image is achieved…
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).
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.
Hepatocellular carcinoma develops in the cell when the cell is mutated in its cell machinery. The mutation at the cellular metabolism level prevents the cell from undergoing apoptosis and thus leads to the higher rate of replication. Chronic hepatitis C causes HCC through cirrhosis and hepatitis B virus genome enters into the cells and causes infection leading to the non-cirrhotic liver HCC.
Figure 1 shows an example of an MRI image from a moving patient. In such cases, use of sedation or general anesthesia is warranted to increase tolerance to an unpleasant but necessary procedure, and to expedite MRI imaging of a distressed patient (Medical Advisory Secretariat, 2003; Shellock, 2011).
Question 1 Breast Magnetic Resonance Imaging (MRI) examinations have been timed carefully to avoid wrong results from the hormonal influences during the normal menstrual cycle. According to Ellis (2009), cyclical hormonal changes are usually manifested in a normally menstruating woman.
MRI AND PET/CT imaging in the Early and late Stage Disease Name Institution Introduction Magnetic resonance Imaging is a type of test that makes use of the energy of the radio wave pulses and magnetic field to make pictures of structures and organs inside the body.
The amalgamation of both practices is tremendously encouraging for the primary recognition and valuation of stroke, for tumour description and for the estimation of neurodegenerative illnesses (Nelson, et al., 1995). Perfusion applications are intended to evaluate the distribution of blood to a vascular bed.
Diffusion weighted imaging (DWI) is an MRI sequence designed to measure the random movements of water particles to further assess different tissue characteristics such as membrane permeability. By virtue of the kinetic
When in use, the machine takes images of the target organ in various angles which are then processed using a computer to yield a picture of high detail of the area selected for observation. Basically therefore, the technique makes use of a computer, an
6 pages (1500 words)Essay
Hire a pro to write a paper under your requirements!
Win a special DISCOUNT!
Put in your e-mail and click the button with your lucky finger
Apply my DISCOUNT
Got a tricky question? Receive an answer from students like you!Try us!
Let us find you an essay for FREE
Contact us via Live Chat, call us at +16312120006or send an email to email@example.com