We have developed a new tumor model, the skin flap pedicle, which is ideally suited for study by such techniques as magnetic resonance imaging (MRI) and spectroscopy (MRS) and positron emission tomography (PET) to evaluate changes in metabolism/physiology in tumors before and after treatment. Heretofore, results from such studies were generally obtained from tumors growing in the thigh or flank region and these sites of growth often compromised the quality of the results, because of the contribution of normal tissues such as muscle and bone. In an attempt to circumvent such problems, we developed a surgical technique for creating a tubular skin pedicle and subsequently transplanting tumors in the lumen of such pedicles. We have successfully grown Dunning Prostate tumors (R-3327) as PEDICLE-TUMORS (PED-TUM). This paper describes the surgical procedure for formation of the skin pedicle, implantation of the tumor, data on the growth and histology and discusses the application of the PED-TUM to research problems. We compare the NMR characteristics of the tumor grown in the traditional SC thigh position with that growth in the pedicle and demonstrate the utility and advantages of the new model for studies of tumor physiological function and structure.