A medical imaging element support unit is for use in fixing a medical imaging element (26) releasably against a region of skin of a subject. The support unit includes a support body (14), having a base for engaging with skin of the subject in use and having a coupling means (22) for releasably coupling the medical imaging element to the support body. A pneumatic positioning mechanism is provided for adjustment of a position of the medical imaging element relative to the support body, wherein an air pump mechanism is arranged for applying air to the pneumatic positioning mechanism. The same air pump mechanism is controllable in use to create a suction force at the skin engaging area for releasable fixation of the support body to the skin. An ultrasound system is also disclosed, comprising the support unit and a medical imaging element in the form of an ultrasound transducer unit.
