Reportage in the interventional neuroradiology service in Pasteur 2 Hospital, Nice, France. Treating a cerebral aneurysm through embolization. This endovascular treatment consists of introducing a catheter into the brain and filling the aneurysm with platinum coils in order to clot it and prevent it splitting. The embolization is carried out under fluoroscopic guidance. The doctor inserts the microguide into the microcatheter.