This invention describes a conception of using a possible thermally stimulated large increase of blood perfusion by magnetic resonance imaging guided high intensity focused ultrasound for targeted drug delivery. The concept can also be used to develop thermally/mechanically activated drugs for targeted drug delivery. Magnetic resonance Imaging (MRI) guided high intensity focused ultrasound (MRgHIFU) was featured as one of the 50 best inventions in the year by TIME magazine last year. MRgHIFU surgery is a noninvasive thermal ablation method that uses MRI for precision target definition, treatment planning, and closed-loop controlled of ultrasound energy delivery. In the process of analyzing the data collected from animal trials for MRgHIFU surgery, we found that the temperature profile of the tissue under thermal blast can only be understood in terms of a thermally stimulated large increase of perfusion. The blood perfusion rate can reach as much as 20 times of the nonnal blood perfusion rate. This TS LIP model, if proven to be true, has important therapeutic applications since 1. Substantial increase in local blood flow can be accomplished with targeted heating of tissue by a number of clinical available techniques. For example, non-invasive heating via focused ultrasound, or minimally invasive procedures such as laser ablation, or radiofrequency ablation, or even by invasive surgery. If cancer treating drugs that rely on blood flow to transport them to the tissue of interest are administered during the temperature elevation, the regions of temperature elevation will receive disproportionately large blood flow compared to normal blood flow rate, and the greater accumulation of the drug in the tissue of interest will result in effective targeted therapy. Since elevated temperature and mechanical vibration should enhance the drug effect in general, we call this, targeted simultaneous enhancement of the quantity and the effect of drugs, approach as thermally stimulated large increase of perfusion (TSLIP) mediated therapy, the TSLIP-mediated therapy. 2. The effectiveness of such therapy can be further increased if this approach is combined with heat/mechanical vibration activated drugs. Such drugs have the added benefit of being able to selectively act on the tissue of interest providing the ability to spare the surrounding tissue. 3. Since thermal dosage by itself is therapeutic, therefore, the combination of thermal treatment and TSLIP-mediated therapy provides extra degrees of freedom for optimal therapy and patient care. 4. Another dimension to this approach is the ability to simultaneously monitor the temperature elevation using imaging techniques such as magnetic resonance imaging (MRI). One implementation could be the approach of MRgHIFU, where the real-time temperature monitoring via MR allows one to monitor the region of thermal dose delivery and the subsequent modulation of perfusion. The combination of administration of both the therapeutic drug, as well as an MR contrast medium, once the target temperature is released, can provide a direct estimation of the increase in local perfusion that can be measured with MR imaging techniques. 5. Another approach for effective therapy and monitoring is the design of drugs that can simultaneously serve as contrast agents for an imaging modality. For example, the therapeutic drug can be designed to have its magnetic resonance relaxivity that can be modulated by temperature or by varying the amount of access to nearby water molecules. In one implementation, for example, when such restricted access to mobile water molecules is removed by heating, or mechanical vibration, these spatial location of these contrast agents becomes conspicuous in MR images. This allows for a real-time visualization of drug delivery and may provide additional control for effective TSLIPmediated therapy.