A method and system for noninvasive monitoring of at least one parameter of a region of interest in a human body. The system comprises a measurement unit and a control unit. The measurement unit comprises an optical unit having an illumination assembly (101A) and a light detection assembly (101B) to generate measured data indicative of collected light; and an acoustic unit (110) configured to generate acoustic waves of a predetermined ultrasound frequency range. The measurement unit provides an operating condition such that the acoustic waves overlap with an illuminating region within the region of interest and substantially do not overlap outside the region of interest. The measured data is indicative of scattered light having both ultrasound tagged and untagged light portions, enabling to distinguish between light responses of the region of interest and the region outside the region of interest.