Rotational angiography

Rotational angiography is a medical imaging technique based on x-ray, that allows to acquire CT-like 3D volumes during hybrid surgery or during a catheter intervention using a fixed C-Arm. The fixed C-Arm thereby rotates around the patient and acquires a series of x-ray images that are then reconstructed through software algorithms into a 3D image. Synonyms for rotational angiography include flat-panel volume CT and cone-beam CT. Rotational angiography is a medical imaging technique based on x-ray, that allows to acquire CT-like 3D volumes during hybrid surgery or during a catheter intervention using a fixed C-Arm. The fixed C-Arm thereby rotates around the patient and acquires a series of x-ray images that are then reconstructed through software algorithms into a 3D image. Synonyms for rotational angiography include flat-panel volume CT and cone-beam CT. In order to acquire a 3D image with a fixed C-Arm, the C-Arm is positioned at the body part in question so that this body part is in the isocenter between the x-ray tube and the detector. The C-Arm then rotates around that isocenter, the rotation being between 200° and 360° (depending on the equipment manufacturer).Such a rotation takes between 5 and 20 seconds, during which a few hundred 2D images are acquired. A piece of software then performs a cone beam reconstruction. The resulting voxel data can then be viewed as a multiplanar reconstruction, i.e. by scrolling through the slices from three projection angles, or as a 3D volume, which can be rotated and zoomed. 3D angiography or Rotational Angiography is used in interventional radiology, interventional cardiology and minimally-invasive surgery. (for examples see: Hybrid cardiac surgical procedure) Clinical benefits range from the visualization of ventricular systems, soft tissue (e.g. tumors) and bone structures in the interventional suite, which allows the evaluation of difficult anatomies, to the detection of bleedings and unintended blockages of other lumen, which might be easily missed in a 2D view and only detected hours later in a post-procedural CT.