A computer-assisted surgical system includes a manipulator arm configured to be coupled to an ultrasound probe and to position the ultrasound probe within a patient and one or more processors configured to perform a process comprising: generating an ultrasound image based on sound waves detected by the ultrasound probe while located within the patient; determining, based on an analysis of the ultrasound image, a contact state of the ultrasound probe, the contact state indicating whether the ultrasound probe is in operative physical contact with tissue of the patient; and controlling, based on the contact state, a positioning of the ultrasound probe.