| The following work investigates spectroscopic MRI data acquired with high spectral and spatial resolutions (HiSS) as a source of information related to early cancer detection. HiSS datasets allow for the acquisition of a water spectrum for each tiny voxel imaged; it is the shape of the waterline and the features within it that is of specific interest to this work.;An initial study to determine the efficacy of early detection with HiSS was performed on a transgenic rodent prostate cancer model where disease progression is similar to that in humans. Images produced by utilizing the voxel by voxel variation in signal intensity of the main peak of the water resonance were compared with conventional images. As previous work in this lab and elsewhere has reported, the waterlines of the small voxels imaged were typically inhomogeneously broadened, producing secondary peaks and partially resolved shoulders at frequencies both above and below that of the main water peak.;Second, we sought to verify that the off-peak components of the waterline were statistically above the noise level, and therefore, not simply due to arbitrary fluctuations in signal. Having demonstrating through phantom and rodent experiments that observed inhomogeneities in the waterline were "real" signal allowed for further investigation of different Fourier components of the waterline as novel sources of image contrast. Specifically, since contrast between different Fourier components of the waterline in a single HiSS dataset themselves differed, this indicated that there were specific anatomic or physiological features that were more visible at different Fourier components.;Finally, images produced by developed analysis techniques exploiting inhomogeneous broadening of the waterline, including the individual Fourier components, were compared with a gold standard of tumor micro-vasculature localization; a super-paramagnetic blood pool contrast agent. It is demonstrated with statistical significance that appropriate analysis of HiSS datasets can identify tumor micro-vasculature without the use of exogenous contrast agents. |
