Echo Planar Imaging, or EPI, Fast Imaging Techniques (MRI) Essay - 1

Echo coplanar Imaging, or EPI, Fast Imaging Techniques (MRI) - Essay ExampleDifferent results have been found from different frame areas which have variable magnetic field strengths thus such body areas end up having varying processional water frequencies. Blood has been observed to have the highest susceptibility as it has iron contents as one of its components. Compositions based on water also have high susceptibility in similarity with air (McRobbie 2007) (a) List the parameters that could be changed to optimize the EPI image in this chance, plus how you would change the parameter (i.e. outgrowth or decrease). (2 marks) Slew rate and the receiver bandwidth Each of the listed parameters has a different way of changing it. For example, the case of slew rate increment, an overall drop-off in echo spacing as well as reduction in nonrepresentational distortion is required for it to be altered. For receiver bandwidth to be increased, an overall reduction in echo spacing, signal to noise ratio and geometric distortion need to be let down (Van Der Zwaag, at el. 2012, p. 129) In a normal scenario, MR equipments take their measure until the trapezoid gradient gets to the flat eliminate. When this time comes, the entropy points will then be sampled by the MR equipments in the direction of the frequency. This implies that no data eruditeness takes place during the rise time. The rise time refers to the time when the gradient is not yet at its negligible or maximum amplitude. However, by employing ramp sampling method, the data points witnessed during the readout gradient switching pot be acquired during the rise time. a) Two different features can be used while employing ramp sampling, and they include 1. Having the geometric distortion backgroundd ramp sampling can be used to reduce the flat top while at the resembling time keeping the Nx constant. This implies that the echo spacing can be decreased consequently minimizing geometric distortion. 2. Inc reasing resolution by keeping the flat top at the same level, more Nx data points can be fitted during readout and thus increasing the overall resolution. b). Using Conjugate entailment Conjugate synthesis is a symmetry property which means that only half of the raw data spaces in the whole MR can be acquired to come up with a Mr image that is complete. The most plummy means to achieving high resolution during a single shot EPI experiments is through having the readout duration on the ky to be as long as possible so as to have only the negative and authoritative kx values. c). Slew rate enhancement d). Echo train length reduction e) Making use of shimming to minimize distortion d). Employing parallel imaging to minimize echo spacing f) . Making use of Multi shot EPI so as to ensure that there are no cases of phase errors building up. g). Through increasing the TE which will in turn increase the transverse magnetization hence larger T2* and T2 (b) Discuss the set up of consequenc es if you optimize the image by increasing the receiver bandwidth. (4 marks) Receiver bandwidth generally describes how fast an MR signal can be digitized. In cases where the receiver bandwidth is generally higher, there is a corresponding faster digitization of the produced image. This is because the cheek of receiver bandwidth is inversely proportional to the time taken during the imaging process. The receiver bandwi