Neuroradiology

2>Neuroradiology

Definition: What is Neuroradiology?

Neuroradiology is a field in medicine, that deals with the diagnostic and treatment of diseases with the help of imaging of the central nervous system.

Which Functions Does Neuroradiology Have?

Neuroradiology is responsible for the imaging of the brain and spinal cord. Diseases and anomalies can be diagnosed based on the images created by MRI and CT. The conditions are, among others:

• Stroke
• Multiple Sclerosis
• Cranial fracture and vertebral body fracture
• Encephalitis or meningitis
• Aneurysms
• Tumors
• Herniated disks
• Myelitis

Disease processes and healing success can also be checked.

Neuroradiological Diagnostic

Methods and techniques of imaging have rapidly developed in the past years. X-ray examinations have lost their significance due to the introduction of computer-based cross-sectional imaging, such as CT and MRI. In the meantime, it has been realized to create high-resolution sectional images of the human body, which enable a precise diagnostic and present a basis for invasive interventions.

Computed tomography is a procedure using X-rays to produce sectional images. A CT examination takes only a few seconds and is a suitable tool for quickly obtaining an overview of injuries in an emergency situation. The CT is particularly good at depicting bony structures so that it is used in neuroradiology in addition to emergency diagnostics when evaluating the cranial bone and vertebral bodies is needed.

CT angiography is a special examination method. It involves bringing contrast agents into the patient's bloodstream, which absorbs X-rays. This allows making the vessels in the brain and spinal cord visible on the CT images. Nowadays, computers can also calculate a 3D image from the generated images so that the vessels can be clearly displayed.

Magnetic resonance imaging is used in medicine to visualize soft tissues in the body. These include, among others, organs, muscles, and tendons. A significant advantage over computed tomography is the absence of radiation exposure since the MRI examination is based on a magnetic field. In neuroradiology, this form of examination is used to evaluate the spinal cord and brain. This examination can be problematic for some patients, as they have to lie still for several minutes in the device, which corresponds to a long narrow tube.

Significant Diagnostic Procedures

The most important diagnostic procedures in neuroradiology are:

• Skull base CT
• CT angiography
• CT perfusion
• Functional MRI
• Magnetic resonance spectroscopy
• Diffusion tensor imaging

Skull base CT is used in emergencies, for example, to evaluate if the cranial bone is broken and if bleeding is involved. This examination can also distinguish bleedings from occluded blood vessels, which lead to insufficient supply in the brain, in strokes. CT angiography describes placing contrast agents into the blood vessels, e.g., through the arm vein and subsequent recording of sectional images in the CT equipment. This allows blood vessels in the brain to be well visualized, and aneurysms or blocked vessels can be detected. Functional MRI shows how the brain works by indicating increased blood flow or oxygen consumption in some regions of the brain. Magnetic resonance spectroscopy is a special procedure that can determine concentrations of specific molecules in a defined area of the body. This allows for obtaining important additional information about brain tissue, which can help to make a diagnosis in severe cases. Diffusion Tensor Imaging describes the absorption of diffusion of water molecules in tissue. In this way, it is possible to visualize pathways that run in the white matter of the brain.

Interventional Neuroradiology

Interventional neuroradiology describes the minimal-invasive diagnosis and therapy of diseases in the central nervous system. For these procedures, catheters are fed through the inguinal- or arm arteries into the brain arteries; similar to the heart catheter.

Important Treatment Methods

Interventions performed in interventional neuroradiology are, among others:

• Vascular dilatation in case of narrowing of the cerebral vessels
• Interventional therapy of an acute stroke with insufficient blood flow to the brain
• Closure of brain aneurysms by of so-called coiling
• Vascular occlusion in tumors of the head and neck region and the spinal column

Which Doctors and Clinics Are Specialists for Neuroradiology in Germany, Switzerland, and Austria?

Specialists in radiology can acquire the additional qualification of neuroradiology by completing further training in neuroradiology. Neuroradiology is established in large maximum-care hospitals, e.g. university clinics and university hospitals, as a separate department independent of radiology. A department for neuroradiology is often not available in primary care hospitals, such as small municipal hospitals. The radiology department carries out imaging of the central nervous system, there.

Sources:

• Linn et al. (Hrsg.): Atlas Klinische Neuroradiologie des Gehirns. Springer 2011, ISBN 978-3-540-89568-8.
• Möhlenbruch, Bendszus: Technische Standards bei der interventionellen Behandlung des akuten ischämischen Schlaganfalls. In: Der Nervenarzt. Volume 86, number 10, 2015, doi: 10.1007/s00115-015-4268-y, S. 1209–1216.
• Rillig et al.: Interventionelle Schlaganfallprophylaxe. In: Herz. Volume 40, number 1, 2015, doi: 10.1007/s00059-014-4198-7, pp. 50–59.
• Hufschmidt et al.: Neurologie compact. 7th edition. Thieme 2017, ISBN 978-3-131-17197-9.
• Masuhr, Neumann: Duale Reihe Neurologie. 6th edition. Thieme 2007, ISBN 978-3-131-35946-9.