The invention relates to a medical diagnostic X-ray apparatus (1) comprising an X-ray source (13), a hollow carrier (5) to which the X-ray source is connected, and a cooling mechanism (3) provided with a cooling means to cool the X-ray source (13) during use of the X-ray apparatus (1). The cooling construction (3) extends completely inside the hollow carrier (5) thus reducing the risk of leakage of cooling means.
