Modern Brain Imaging Methods in Preoperative Screening

Imaging Anatomical - Functional - Dissection imaging

Our brain is perhaps the most complex organ in our body, regulating the functions of our body with the help of more than 86 billion neurons. Some of the functions we take for granted, such as breathing or the heartbeat, as well as other more complex ones, such as our thoughts or reactions, are regulated by our brain.

Figure 1:
The basic structures and anatomy of the brain

Modern imaging of the brain

Imaging of the human brain is now performed through a variety of medical imaging systems used in clinical practice, including:

• Magnetic Resonance Imaging (MRI)
• Functional magnetic resonance imaging (fMRI), which identifies structures and regions of the brain associated with specific brain functions
• Diffusion Tensor Imaging (DTI), which identifies the bundles of the brain that serve specific functions.

Functional Magnetic Resonance Imaging (fMRI)

The fMRI allows simultaneous data acquisition during specific, pre-planned procedures performed by the patient. This allows us to isolate and highlight very specific brain functions, such as speech and movement, by measuring the blood flow of the brain regions corresponding to the areas responsible for the respective functions.

The fMRI at the "Agios Loukas" Clinic

The Laboratory Departments of our Clinic include, among others, a new generation MRI scanner that allows its operation as an fMRI imaging system. In collaboration between the Epilepsy and Video-Electroencephalography Unit and the Biomedical Imaging and Graphics Laboratory (BIOMIG - biomig.ntua.gr) of the National Technical University of Athens, we have implemented appropriate data collection protocols, such as typical protocols for activation of speech and movement areas, following a collaboration with YALE University, USA, in order to apply fMRI in preoperative neurosurgical screening. At the same time, protocols are being completed for the activation of memory and hippocampal areas of the brain.

Figure 2:
Example of region activation with functional magnetic resonance imaging.

Diffusion Tensor Imaging (DTI)

DTI is a method that allows structural imaging of brain bundles. Brain bundles are the connections of brain neurons from region to region. Specific bundles are known to serve specific brain functions such as movement, vision and speech. Their imaging allows treating physicians to draw conclusions about the type of condition and plan the surgical approach to avoid unwanted side effects.

Figure 3:
Example of a bundle design.

DTI at the "Agios Loukas" Clinic

DTI has now begun to be applied in our clinic in diseases and lesions located near areas and bundles that serve basic brain functions. The use of this method gives neurosurgeons an additional powerful and reliable tool in their toolbox. In countries abroad, DTI is widely used in major surgical centers. In combination with the acquisition of corresponding anatomical MRI images, it is possible to segment the brain into anatomical regions, to volume measure each region, and to extract and measure brain damage, offering the treating physician direct and quantified patient monitoring.

Figure 4:
Structural imaging of the brain, direct and quantified patient monitoring via DTI.

Preoperative control

Preoperatively, brain imaging through a combination of the techniques mentioned above is a basic requirement in order to:

• Identify any brain damage
• To determine the resection limits of each lesion, as well as the eugene cortex limits, so that they can then be used by the specialist doctor during surgery

For this reason, accurate imaging and processing of the collected data is of paramount importance in preoperative monitoring and surgical planning.

Preoperative check-up at the "Agios Loukas" Clinic

In our clinic, in collaboration with the Biomedical Imaging and Graphics Laboratory (BIOMIG - biomig.ntua.gr) of the National Technical University of Athens, we optimized the MRI protocols, aiming at the best possible spatial and temporal analysis of the collected data. The simultaneous imaging of the analyses through our modern techniques, which in some cases surpasses the largest surgical centers in Europe, reduces the risk of surgery, while providing the possibility of better access to areas and structures that in previous years were difficult to reach.

Under the supervision of the Director of the Radiodiagnostic Laboratory Dr. Anastasios Prousalis, the medical radiologist Dr. Nikolaos Kondylidis and the medical neurologist Dr. Kyriakos Garganis and in collaboration with the doctor of electrical and computer engineering of the National Technical University of Athens Kostakis Giatis, we offer the following services:

• Functional imaging of speech areas, areas of movement, at rest and with simultaneous electroencephalography
• Imaging of bindings
• Structural/Volumetric Analysis
• Imaging of Electrical Sources
• Import of analysis data directly into PACS and neuropil systems

KEIMENO:

Kostakis Giatis, School of Electrical and Computer Engineering, National Technical University of Athens, Athens.

Dr Kyriakos Garganis, Epilepsy and Video-Electroencephalography Unit, "Agios Lukas" Clinic, Thessaloniki

Dr. Nikolaos Kondolidis, Department of Radiology, "Agios Loukas" Clinic, Thessaloniki, Greece

Dr. Anastasios Prusalis, Department of Radiology, "Agios Lukas" Clinic, Thessaloniki, Greece

‍