Magnetic resonance imaging (MRI) provides excellent soft tissue contrast and enables structural, functional, and metabolic imaging of the human body. One primary clinical application of MRI is the neuroimaging of tumors, which demands both multi-parametric qualitative and quantitative information from MR scans.
Although the role of the quantitative MRI (qMRI) is well accepted, it suffers from long acquisition times leading to patient discomfort, especially in geriatric and pediatric patients. Quantitative imaging is also critical to estimating temperature during MR scans of patients with implants and leads. The radiofrequency stimulus pulses of an MRI exam can couple to conductive implants, resulting in eddy current propagation and consequential heating. The heating can lead to third-degree burn lesions along the surfaces of titanium joints, deep brain stimulation (DBS), and pacemaker leads. Such challenges raise safety concerns in MRI, requiring fast and accurate temperature estimations to ensure patients’ safety.
This thesis aims to tackle the abovementioned challenges in MRI, specifically focusing on developing novel quantitative imaging approaches using magnetic resonance fingerprinting (MRF) methods and applications. MRF is a framework that allows measuring multiple tissue properties in a single acquisition.
In the first chapter, we extend the current implementation of MRF and introduce tailored MRF (TMRF), an imaging method offering qualitative and quantitative information simultaneously, with promising results in differentiating healthy and pathological tissues. This method increases scanner efficiency and decreases acquisition time for neuroimaging while simultaneously providing qualitative and quantitative imaging measures. We demonstrate these advances in in vitro phantoms healthy volunteers- and pediatric patient- populations.
In the second chapter, we address the issue of MRI safety for patients with conductive implants like deep brain stimulation (DBS) leads by using MRF-based thermometry (MRFT) to accurately predict and monitor temperature near these implants during MRI scans, enhancing safety and efficacy for image-guided procedures and imaging patients with such implants. Successful approaches will be incorporated into an imaging protocol to increase safety and effectiveness for image-guided lead placement and imaging patients with implanted leads. To validate MRFT in vivo in patients, we conducted a patient study using MRFT to evaluate the accuracy of MRFT in vivo near DBS lead.
In the third section, we implement an open-source MRF package (OMEGA) for a multi-site, multi-field strength MRF repeatability study, demonstrating its accuracy and repeatability of MRF across various conditions.
| Identifer | oai:union.ndltd.org:columbia.edu/oai:academiccommons.columbia.edu:10.7916/avj4-w218 |
| Date | January 2024 |
| Creators | Qian, Enlin |
| Source Sets | Columbia University |
| Language | English |
| Detected Language | English |
| Type | Theses |
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