Multipurpose RF Coil for Low Tesla MRI

Abstract

Magnetic Resonance Imaging (MRI) is one of the most promising imaging modality to detect abnormalities in the human anatomy. It helps clinicians to diagnose different diseases which cannot be detected in other imaging techniques. For instance, early brain stroke can be detected with the help of MRI instead of Computed Tomography (CT). MRI is preferred whenever soft tissue study is needed whereas CT scan is performed mostly when quick diagnoses are required in emergency such as accident and trauma. A typical MRI system comprises a magnet, RF system, gradient system and an image reconstruction system. The RF system is further divided into a transmit and receive section. The former consists of RF power amplifier and transmit coil in addition to other transmitter components. The receiver, on the other hand, has pre-amplifier and receives coils. Receive coil is an important component to acquire the MR signals. This thesis focuses on studying the operation of receive coils for low tesla or permanent magnet MRI system followed by the design and implementation of a multipurpose flexible coil suitable for integration with Siemens Magnetom C MRI scanner. The circuit is implemented in ADS to achieve the resonance at 14.6MHz. The PCB layout is done in Altium Designer and finally tested with an MRI system. The image quality of the designed coil is satisfactory according to the Original Equipment Manufacturer (OEM) specification. SNR test carried out on Siemens Magnetom C MRI demonstrates an SNR of more than 60, that is higher than the required threshold of 56. This thesis lays the foundation of indigenous design and implementation of MRI Coils for use in Pakistan.