A system and method are presented for use in monitoring blood flow conditions in a region of interest in a patients body, such as a brain or kidney region. The monitoring system comprises a blood flow sensing system, and a control unit configured for communication with the sensing system to operate and to process and analyze output data of the sensing system. The blood flow sensing system is configured and operable for measuring a blood flow parameter from a first region being a region of interest in a patients body and generating first measured data indicative thereof, and measuring a blood flow parameter in a second region being a tissue region outside the brain region and generating second measured data indicative thereof The control unit is configured for operating the sensing system for carrying out substantially simultaneous measurements on the region of interest and the tissue region outside the region of interest and recording the first and second measured data, and configured and operable for determining a predetermined function characterizing a relation between the first measured data and the second measured data, and generating output data indicative of said relation, being indicative of the blood flow condition in the region of interest.
