An apparatus (11, 21, 31) for acquiring panoramic and optionally CBCT volumetric images, comprising an X-ray source (5) projecting a collimated X-ray bundle through a patient, a bi-dimensional X-ray sensor (6) placed so as to measure the intensity of the radiation after it crossed the patient, a support group supporting said source (5) and sensor (6), which group comprises a C-arm (4) to which said sensor and said source are fixed/fixable, said C arm (4) hanging from a cantilevered arm of a vertically mobile support (3) which is supported by a post (2) a mechanical system capable to allow the rotation and the translation of said C-arm around the patient, so as to acquire radiographic images from different positions a patient positioning device (7) for positioning the patient in an intermediate position between said X-ray source (5) and said sensor (6). According to the invention said post (2) comprises a stationary internal post (41) and a mobile external post (42) sliding on the internal post (41) with a telescopic movement, the mobile external post (42) being provided on the side of the said mobile external post (42) opposite to the C-arm with a continuous slot extending in the direction of sliding of the said external post on the said internal post forming a passage for fixing means of the internal post (42) to a stationary support such as a wall.
