MRI Gradient Coils - Essay Example

Project (MR gradient coils: action and performance) My partner, Mrs. Xxxxxxxx sent a copy of her research paper requesting for critic or review of the paper. Said research dealt on Magnetic Resonance Imaging or MRI, its important parts, and its advantage/s over other medical imaging techniques. She described MRI as a non-invasive mode of achieving high-contrast image quality of the body which makes it the most-preferred choice of physicians. She also identified gradients in the MRI as the most crucial and integral part of the magnetic resonance system for spatial encoding signals . The paper generally aims to explain the degree of performance and participation of gradients in relation to achievement of high-image quality of body parts covered by the MRI. Commendations According to the author, the advantage of MRI technology is that it is a non-ionizing and non-invasive imaging technology. This may be credited to the use of gradients in MRI. The author explained the magnetic resonance gradients coils concept, their action, speed and performance. She highlighted several important points on how gradients help in the MRI. Thus, she emphasized the the mechanism of the gradient coils in encoding signal spatial along the gradients axis, the manner of selecting the slice and the thickness. She further explained the mechanism by which the steep and shallow gradients are used in selecting slice thickness. Finally, the essential properties that should be considered in gradient coils to get high imaging qualities were examined and the adverse the effects of gradients on biological tissues like peripheral nerve stimulation, acoustic noise, muscle twitching and thermal burns were discussed. Affirmations In the second paragraph on the first page of the abstract, the researcher wrote about the units that were used in measuring the magnetic field strength but she failed to write about the unit that was used for measuring the gradient field strength. Why? Also, the researcher defined the gradients in line 10 of the last page. It could have been better if it was placed in the Introduction rather than in the last page since definitions were intended to introduce the reader to the significant terms used in the writing. The researcher wrote in the second paragraph of the abstract, “Human research magnets of 7T and 8T are operation in several site worldwide.” However, it is quite disturbing why these types of magnets were mentioned in the abstract but nothing in the research paper discussed these things. Said sentence therefore appears to be irrelevant. Thus, the researcher must either discuss these types of magnets in the body of the paper or better yet, totally delete the above-quoted sentence. In addition, the author mentioned in the introduction that he/she will elaborate on the different gradient types and designs thereof. However, perusal of the body of the research paper would show that only the three (3) main ingredients, to wit, z, y and x, were discussed as part of the MR system. In the last paragraph of the summary, the author stated, “the distinct advantages over normal radiographs and CT examinations, is that it does without the delivery of ionizing radiation to the patient”. I respect the author’s view; however, I cannot agree on this as MRI gives precise contrast differences between soft tissues that significantly help in diagnosing abnormalities than other normal radiographs and CT examinations. Recommendations I respectfully recommend that the researcher e-write the abstract and avoid putting much information therein as the abstract serves as a skeleton of the whole paper only. Thus, there is no need to elaborate or discuss things in this part of the paper. Instead, the details should be written in the body of the paper or discussion. The introduction is relatively short as compared with the abstract. No pictures or diagrams were provided in the research paper. These things are very important in order to simplify the meaning of the contents of the paper or give an overview of what were written in the paragraphs. It is also necessary to highlight clear definitions of the slew rate, its effects on gradients’ performance and its units. It must be borne in mind that slew rate of the gradients determine how fast the gradients can be switched on and off. The gradients’ strength is calculated thru the variations that are created in the field strength over a specific distance of the coil, and it must be directly proportional to the amount of current provided by the coil itself. Gradients with strength of 2.0 mT/m/A and 100-200 T/s are used in clinical MRI system. Further, the researcher failed to write in the performance section about the shimming process which is vital in maintaining homogenous magnetic field since gradients can be used in performing this task. The fact also that open magnets have different gradients configurations in comparison with closed magnets will also greatly improve the research paper. It is of general knowledge in this field that there are different designs considered for the three (3) gradients in the MRI system but the researcher did not mention any of them. Some gradient designs should have been presented and discussed thoroughly as they are used for Z axis gradient like Maxwell coil pair and Helmholtz coil while others are used for x and y axes like Golay coil. The effects of different designs geometry and gradients with emphasis on gradients’ performance and image quality must be meticulously explained. The time in which the gradients are switched on, is associated with other RF pulses timings during image acquisition, thus, this must also be clearly explained. The efficient shielding and effects of eddy currents’ interference with image quality and artifacts must also be discussed in the performance section of the review. More elaborate information is likewise required with regard to how can physiological effects on patients be limited or controlled, like acoustic noise, peripheral nerve stimulation, thermal effects ,muscle twitching and the like as they are among the most significant issues that worry patients during MRI procedure. Overall considered, the research paper does not provide the information expected from its title and/or subject. This may be improved if the researcher would add more data and would explain each and every detail thereof. Otherwise, the paper will appear to be more of a summary of a general concept rather than achieve its ultimate purpose of laying down much-needed facts and explanation of each concept or process. Read More