Techniques

The special MRI techniques play a significant role in detecting and assessing the extent of cancer, but also in investigating many other conditions. These techniques significantly increase diagnostic accuracy when identifying and characterizing a lesion, contributing to selecting the most suitable treatment and to properly monitoring the treatment result.

We take advantage of all the benefits of modern imaging through MRI scans, ultimately striving for advanced imaging, adjusted to each individual patient.

MRI is a complex imaging method that is constantly advancing. Many different parameters contribute to final image quality and proper interpretation of the findings.

The following contribute to optimal quality:

Our state-of-the-art equipment
Optimal protocol application, adjusted to each anatomical area and clinical question
Post-processing, working closely with our dedicated team of radiophysicists
Combination of high-resolution anatomical images with special functional techniques
The specialization, knowledge and experience of our radiologists

The Unit has been described as a center of excellence by Siemens for the application of technological advancements, supported by our contemporary equipment. We are also a training center for other doctors working in centers that carry the company's equipment.

MRI TECHNIQUES

SPECTROSCOPY

This method detects chemical substances (metabolites) that cannot be identified by conventional MRI, assessing the metabolic activity of an organ. Metabolites are essentially indicators that further identify the tissue.

The technique is mainly used to identify neoplastic diseases and other conditions, such as demyelination, neurodegenerative disorders and metabolic diseases.

In Oncology, distinct changes in the concentration of chemical substances offer additional information, which is significant for:

Identifying and assessing the aggressiveness of the tumor
Making a differential diagnosis of neoplasms and other conditions
Designing a pretreatment plan for the extent of the neoplasm
Monitoring the treatment result

The combination of spectroscopy with high-resolution anatomical imaging and other special functional techniques (diffusion, perfusion) is called multiparametric MRI.

MULTIPARAMETRIC STUDY

A multiparametric study is the combination of special MRI techniques with high-resolution anatomical imaging. This provides information on the number of cells, blood flow and metabolic activity of the tumor.

A multiparametric study combines many special techniques, such as:

Diffusion (DWI/IVIM)
Perfusion (DCE/DSC)
Spectroscopy
High-resolution morphological images

It is used to investigate cancer detected in many organs, such as the brain, neck, breast, prostate, rectum, uterus and other.

When is a multiparametric study used?

Early detection of cancer.
It detects clinically significant cancer with great accuracy, even if it is small in size.
Improved biopsy precision.
It detects suspect areas, assisting in collecting a biopsy sample from the right area, without missing the cancer.
Selection of suitable treatment.
It assesses the extent of cancer (staging) more accurately, leading to the selection of the most suitable treatment method (surgery, chemotherapy or radiotherapy).
Monitoring of treatment result.
It assists in early recurrence detection.

PERFUSION (TECHNIQUES: DSC, DCE, ASL)

It is a dynamic study of the perfusion of an organ in terms of small vessels (capillaries) and identifies areas with pathologic perfusion.

The use of the Perfusion technique offers to following information to Oncology:

It identifies the tumor (high/low perfusion).
It assesses the most aggressive areas and estimates the total size of the tumor.
It evaluates the most suitable position for a biopsy (targeted towards the most aggressive areas).
It selects the most suitable treatment method (surgery, radiotherapy or chemotherapy).
It plans the radiotherapy to include the entire extent of the lesion in the area to receive radiation.
It evaluates the treatment result.
It identifies the extent of response to treatment.
It assists in early recurrence detection.

The combination of the perfusion technique with high-resolution anatomical images and other special functional techniques (diffusion / spectroscopy) is called multiparametric MRI.

DTI - tractography

This technique is used to provide images of the neural fiber interconnections in the brain and spine. This assists in mapping the complex neural connections in the brain white matter.

Tractography allows us to identify areas with displacement or destruction of white matter tracts. The mapping of the area is performed prior to surgery or radiotherapy planning, so the neurosurgeon may select the most suitable access, maintaining the functional connections wherever possible and avoiding the creation of a permanent neurological deficit. It is also used to investigate numerous conditions of the nerves and white matter.

FUNCTIONAL MRI (fMRI)

Compared to Tractography, which maps complex neural connections in the brain white matter, Functional MRI depicts the functional areas in the cerebral cortex, such as the motor cortex and language center.

Functional MRI is a special non-invasive method used to stimulate and then provide images of the functional areas of the cerebral cortex.

In Neurooncology, it is performed prior to surgery, as a mapping method. Through the information it provides, neurosurgeons may keep away from the functional centers during surgery and avoid causing permanent damage to the patient (e.g. palsy or aphasia).
Depending on the area of the brain that needs to be depicted, during the exam, patients are asked to execute a series of simple commands (e.g. finger movement when examining the motor cortex).
The data is incorporated in a neuronavigation system, allowing the neurosurgeon to map the functional brain centers during surgery.

MR NEUROGRAPHY

CEREBROSPINAL FLUID (CSF) FLOW STUDY

This is an MRI technique used for quality and quantitative assessment of the cerebrospinal fluid (CSF) flow. It assesses CSF pulsations and flow velocity in the brain.

In some cases, the results may assist in selecting the most suitable treatment (shunt placement or not).

It is suitable for various conditions, such as:

Chiari malformation
Normal pressure hydrocephalus
Sylvius aqueductal stenosis

DYNAMIC MR ANGIOGRAPHY (BRAIN, NECK, SPINE)

All the latest angiography techniques are performed within the Unit, aiming at high-resolution imaging of the central nervous system arteries and veins.

The techniques include Dynamic (4D) MR Angiography of the brain/neck, with image scans every 1-2 seconds upon administration of contrast medium, similarly to digital angiography.
This dynamic exam allows us to assess the flow in large vessels (TWIST – 4D contrast enhanced MRA) and is ideal for conditions such as arteriovenous malformation (AVM), giant aneurysm and venous conditions. It also assesses the early perfusion of tumors.

CARTILAGE MAPPING (T2 MAPPING)

This is a special MRI technique that assesses the cartilage in joints, such as the knee and the knee joint condyles. It accurately identifies any cartilage deterioration at early stages, when it is not visible through conventional techniques. This way, it provides significant information to orthopedic surgeons about the extent and stage of osteoarthritis and other cartilage conditions.

CONVENTIONAL MRI TECHNIQUES

CONTRAST MEDIUM

The special multiparametric scans for dynamic angiography and oncologic imaging require double the standard concentration of contrast medium gadobutrol* (Gadovist 0.1M). This ensures better imaging in dynamic studies, greater concentration of the medication in smaller administered doses (protocols that require double or triple the standard concentration of the contrast medium) and lower risk of complications in patients with kidney failure (macrocyclic contrast medium).

Comparative Studies of Different Gadolinium Agents in Brain Tumors: Differences between Gadolinium Chelates and Their Possible Influence on Imaging Features
AJNR 2010 31: 981-982