Project Summary An Academic-Industrial partnership between scientists and clinicians at the University of Texas Southwestern (UTSW) Medical Center and Philips Research Hamburg and Philips North America (Philips) has been formed with the purpose of translating the novel molecular MR imaging method, Chemical Exchange Saturation Transfer (CEST), into a clinical tool for the assessment of Small Renal Masses (SRMs). CEST has already demonstrated feasibility in neurooncology applications. The management of SRMs is challenging because a substantial number of them are benign or indolent malignant tumors, leading to patient exposure to unnecessary morbidity from biopsies and surgery. Non-invasive distinction between benign/indolent tumors and aggressive tumors would allow for better risk stratification and patient management. While novel, CEST has already been adopted by certain clinical centers for assessment in neuro oncology. Recently, our group demonstrated the promise of CEST to the characterization of breast lesions. Here, we propose to broaden the application of CEST to renal oncology by addressing the inherent challenges of application of CEST in the abdomen and by optimizing CEST in patients with SRMs. Our hypothesis is that technical development of CEST-MRI allows observation of aggressive tumor microenvironment in SRM. Our goal is to advance CEST methodology to become a part of comprehensive SRM evaluation protocol. The goals of the project will be achieved via the following Specific Aims: Aim 1: To develop and optimize CEST methodology for SRMs on 3T human MRI system. This is technical development Aim, where we will evaluate several approaches addressing major issues associated with translation of CEST to kidney oncology applications: (i) improved resolution and fat separation, (ii) acceleration of acquisition using pseudo-cartesian and undersampled algorithms,(iii) motion correction and (iv) advanced Z-spectrum analysis methods. Aim 2: To evaluate the optimized CEST-MRI as a predictive biomarker of SRM hystology. The Aim's focus in on the translation of the CEST technology to SRM patients: (i) evaluation of the optimized in a group of SRM patients: (ii) correlation of the CEST-MRI measurements with histopathology results and correlation of CEST-MRI with glycogen deposition.