Date of Graduation
Statler College of Engineering and Mineral Resources
Chemical and Biomedical Engineering
Matthew C. Valenti.
Standard localized magnetic resonance spectroscopic sequences employ single quantum coherences for excitation and detection. This results in a complex spectra containing large number of resonances. In this thesis we have developed a novel volume localized spectroscopic technique that excites multiple quantum coherences in coupled spin clusters (metabolites) and then reconvert them into single quantum coherences for detection. This results in filtering of uncoupled resonances and also suppresses water with high efficiency. The resulting spectra is reduced in complexity due to the absence of uncoupled resonances.;The technique has been developed in volume localized mode and implemented on a 3T scanner. The technique has been designed to get single-scan coherence pathway selection under gradient-controlled echo filtering, ensuring optimum use of the dynamic range of the receiver electronics.;The multiple quantum preparation sandwich consists of 90° -- t1 -- 90° RF pulse sequence. The period t1 can be optimized for maximizing the desired multiple quantum coherence. The final 90° pulse reconverts the multiple quantum coherences into single quantum coherences. The slice selection gradients are combined with the three RF pulses for volume localization.;The sequence has been tested on phantoms of ethanol and ethyl acetate. The singlets are suppressed as expected. Only the double quantum coherence are able to pass through the double quantum coherence pathway. Preliminary in vivo results for identification of EMCL and IMCL in human calf muscle has been presented.
Ramamurthy, Senthil, "Localized double-quantum filtered correlated spectroscopy on 3T MRI/MRS scanner" (2005). Graduate Theses, Dissertations, and Problem Reports. 1882.