Creation of a low-cost magnetic resonance system for the early detection of preeclampsia

Almazrouei, N.K., 2021. Creation of a low-cost magnetic resonance system for the early detection of preeclampsia. PhD, Nottingham Trent University.

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Abstract

The placenta is a temporary organ that develops after the implantation of a fertilized egg in the uterus, and it functions as an interface between the mother and the foetus to provide sufficient foetus nutrition. Various studies have shown that the magnetic resonance relaxation times of the placenta change during pregnancy, which could be an early indicator of a disease, such as preeclampsia (PE). However, magnetic resonance imaging (MRI) is not a suitable routine for pregnant women due to cost and availability. Low-field unilateral nuclear magnetic resonance (NMR) is a low-cost alternative capable of measuring relaxation times at a single point in space. Although the frequently adopted ultrasound imaging offers an easy technique to locate the placenta, it does not have the potential for early diagnosis of diseases like PE. Therefore, combining the two modalities, (ultrasound and low-field NMR) opens up a novel diagnostic approach at a much lower cost. This thesis aims to develop a low-field unilateral NMR system capable of measuring the relaxation time parameters at a distance from the sensor surface equivalent to the human placenta position.

This study reports the development of a low-field magnetic resonance system, called NMR-CAPIBarA (Clinical Assessment of Patients Implemented with Bar magnet Arrays), capable of measuring spin-lattice relaxation time (T1) and effective transverse relaxation time (Teff2 ) covering the whole range of values relevant to the developing placenta. Two different materials were used to mimic the placental tissue relaxation time values presented in previous literature: PDMS silicone oils representing Teff2 and full-fat milk powder solution representing T1. The low-field electronic system was operated at a magnetic field of 18 mT and was successful in generating and detecting NMR signals using two types of radiofrequency coils: a solenoid and a printed circuit board surface coil, paired with the constructed planar magnet. The most significant result is the positive correlation between the relaxation times measured on the developed system when compared to the same measurements made by a commercial MRI scanner. In particular, the values obtained from the different silicone oil viscosities showed the capability of the low-field system to provide quantitative relaxation measurements over a range of required values to predict the health of the placenta, assuring that the proposed diagnostic approach is quite promising.

Item Type: Thesis
Creators: Almazrouei, N.K.
Date: October 2021
Rights: This work is the intellectual property of the author. You may copy up to 5% of this work for private study, or personal, non-commercial research. Any re-use of the information contained within this document should be fully referenced, quoting the author, title, university, degree level and pagination. Queries or requests for any other use, or if a more substantial copy is required, should be directed in the owner(s) of the Intellectual Property Right.
Divisions: Schools > School of Science and Technology
Record created by: Linda Sullivan
Date Added: 05 Nov 2021 15:00
Last Modified: 05 Nov 2021 15:00
URI: http://irep.ntu.ac.uk/id/eprint/44629

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