Ryan Nicholas Schurr, Presenter: Nothing to Disclose

Saba N. Elias MSc, Abstract Co-Author: Nothing to Disclose

Wenbo Wei, Abstract Co-Author: Nothing to Disclose

Jochen Keupp PhD, Abstract Co-Author: Employee, Koninklijke Philips NV

Michael Vinzenz Knopp MD, PhD, Abstract Co-Author: Nothing to Disclose

Guang Jia PhD, Abstract Co-Author: Nothing to Disclose

Steven Heymsfield, Abstract Co-Author: Nothing to Disclose

Multi-parametric magnetic resonance imaging (MRI) is used to aid in the diagnosis of prostate cancer. Magnetization transfer MRI (MT-MRI) may provide a complementary mechanism to reveal molecular-based contrast between the tumor and benign prostatic tissue. This study investigates the molecular mechanisms of MT-MRI of prostate cancer.

Eighteen prostate cancer patients were imaged on a 3 Tesla MRI system (Philips, Best, Netherlands) before undergoing prostatectomy. A saturation pre-pulse was applied at frequencies ranging from -8 to 8 ppm with a power of 4 uT. Images were acquired using a single-slice, single-shot turbo spin echo sequence. From MT-spectral data, bound proton (associated with immobile macromolecules) and free proton (free water) pools were modeled as separate Lorentz functions using IDL. Parameters describing the full-width at half maximum (FWHM) and maximum magnitude of the bound and free proton components of the MT-spectra were obtained for the PZ, CG, and tumor regions of interest.

The magnitude of the bound pool is 0.15 ± 0.05 for the PZ, 0.21 ± 0.03 for the CG, and 0.22 ± 0.05 for the tumor. This is significantly different between the PZ and the tumor, but not between the CG and the tumor (p=0.001 and p=0.12, respectively). The magnitude of the free pool is 0.77 ± 0.02 for the PZ, 0.76 ± 0.03 for the CG, and 0.75 ± 0.03 for the tumor. This is significantly different between the PZ and tumor, but not the CG and tumor (p=0.002 and p=0.142, respectively). The FWHM of the free pool is 7.4 ± 1.0 ppm for the PZ, 8.3 ± 0.6 ppm for the CG, and 8.2 ± 0.7 ppm for the tumor. This is significantly different between the PZ and CG, and the PZ and tumor (p=0.001 and p=0.0002, respectively).

Our data shows higher magnitude of the bound pool in the prostate cancer and CG regions, revealing greater concentration of immobile macromolecules, and a lower magnitude of the free pool in prostate cancer regions, indicating less free water in cancerous tissues than the PZ.

Modeling the MT-spectra of the regions of the prostate provides immobile macromolecular and water information, useful for the application of MT-MRI as a unique and complementary method of improving contrast between tumor and benign prostate tissues.

Schurr, R, Elias, S, Wei, W, Keupp, J, Knopp, M, Jia, G, Heymsfield, S, A Two-Pool Modeling for 3 Tesla Magnetization Transfer MR Imaging of Prostate Cancer.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045492.html