A method of and device for acquiring in-vivo images or quantitative/qualitative data (perfusion, blood flow, vascularization, contrast enhancement, selective blood supply management) of interior parts of the human body (20) is described, using an imaging system (21) and including the steps of positioning the body (20) relatively to the imaging system (21), applying a respiratory resistance device (10) to the respiratory system of the body (20), and performing an image acquisition step during or concomitantly an inhalation/inspiration/suction or exhalation/Valsalva/expiration phase, during which the body provides suction or exhalation against a resistance as provided by the respiratory resistance device (10).