Zusammenfassung
Zu den neuroophthalmologischen Erkrankungen gehören Läsionen der Sehbahn einschließlich der Retina und des Sehnervs, Anomalien der Augenstellung und/oder -motilität sowie Pupillenstörungen [1]. CT und MRT spielen bei der Diagnosestellung, der Ausbreitung eines Krankheitsprozesses und differenzialdiagnostischen Überlegungen eine herausragende Rolle. Ziel dieses Fortbildungsartikels ist es, dem Augenarzt einen Überblick über diese Untersuchungsverfahren und ihren Einsatz bei für den Augenarzt relevanten Erkrankungen zu geben.
Abstract
Computer tomography (CT) and magnet resonance imaging (MRI) are valuable imaging tools in order to examine various pathologies of the visual pathways. The advantage of CT is its short acquisition time of a few minutes, its availability making it an ideal tool in emergency medicine. It is extremely valuable in patients with cranio-cerebral trauma when an orbital or skull fracture or an intracerebral haemorrhage has to be assessed. In addition, CT-Angiography is used in the management of patients with an acute stroke. CT is mandatory to visualize the orbit in many conditions. The most important disadvantage is its use of ionizing radiation. Thus, CT is contraindicated in pregnant woman. Contrast of soft tissue as brain tissue is inferior compared to MRI. The latter has a high sensitivity in visualizing all kind of brain pathologies including tumours, inflammatory conditions or brain oedema as a result of a stroke. In contrast to CT, MRI (without contrast agent) can be used
in pregnant women. The disadvantages of MRI are its long acquisition time, its contraindication in patients with metallic implants including pacemaker and its low resolution of bony tissue. Both imaging tools are often used in a complementary way in many orbital diseases, pathologies affecting bony structures, pathologies with calcifications and in stroke patients.
Schlüsselwörter
Neuroradiologie der Sehbahn - Computertomografie - CT - Kernspintomografie - MRT
Key words
neuroimaging - visual pathways - computer tomography - CT - magnet resonance imaging - MRI
