Why is brain imaging important

Consequently, an additional achievement of fMRI becomes obvious: fMRI does not only allow the detection of altered brain activation, but also of altered brain connectivity, indicating disturbed communication of brain areas. And indeed schizophrenia that has long been described as a disorder of disconnectivity, could be empirically linked to altered functional Meyer-Lindenberg et al. By allowing the investigation of glutamate in the prefrontal cortex of patients with schizophrenia, MRS helps to solve another puzzle of the cognitive deficits in schizophrenia, Poels et al.

Moreover, attempts to investigate molecular processes in the brain by means of fMRI are the imaging genetics studies that combine genetic information for e. However, using MRS the concentration of only few neurotransmitters can be estimated, and imaging genetics studies might neglect epigenetic effects, while PET has a wide range of possible molecular targets in the brain that can be directly assessed.

Notwithstanding the additional advantages and necessities of MRS and imaging genetics studies, a combination of f MRI and PET would allow a direct comprehensive assessment of the functioning of individual brain regions, as well as the interplay on the level of the whole brain see Figure 1 for a schematic comparison of PET and f MRI. Figure 1. Generally, in PET the advances are driven by the development of selective radioligands i. However, improvements of the specificity of molecular imaging probes invariably go along with the loss of effectual resolution as the orientation guide—the accumulation in the non-target tissue is decreased.

Hence, bimodal imaging techniques that combine the outstanding molecular imaging probabilities of PET with imaging techniques with a better spatial resolution were developed.

Hence, despite the exceptional technical challenges that had to be mastered Pichler et al. While the determination of increases in neural activity and metabolism by the BOLD effect at first glance resembles static tracers that track the hemodynamics i. Hemoglobin is not able to penetrate the blood brain barrier but as it is triggered by the readily diffusible molecule oxygen, it virtually reports on metabolism beyond the blood brain barrier.

Hence, this is the first time that it is possible to directly and simultaneously investigate the activity of neurotransmitters along with the activity and connectivity of a brain region. This combined assessment will give rise to a next generation of understanding brain function in healthy persons and patients with mental illnesses, and thus gives rise to high promise on the way to personalized therapies—the great white hope in medicine.

Despite the complexity of the brain function, advances in brain imaging techniques, in particular PET and MRI have boosted the research in the structure and function of the human brain. MRI has become the main modality for clinical neuroimaging. While economical restrictions and unbalanced safety concerns halt the development of novel tracers, fMRI hemodynamic based strategies have strongly advanced the progress of neuroimaging. The molecular imaging tracers predominantly radiotracers for PET provide the basis not only for a better understanding of molecular processes in the brain, but also for the stratification procedures essential for the safe development of individualized therapies.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Bucerius, J. JACC Cardiovasc. Imaging 5, — Burns, J. Structural disconnectivity in schizophrenia: a diffusion tensor magnetic resonance imaging study.

Psychiatry , — Catana, C. Cowper, S. Scleromyxoedema-like cutaneous diseases in renal-dialysis patients. Lancet , — U S A 98, — Imaging 39, — Hesse, S. Kindermann, S. Review of functional magnetic resonance imaging in schizophrenia.

Kreisl, W. Brain , — Logothetis, N. Neurophysiological investigation of the basis of the fMRI signal. Nature , — Maarrawi, J. Brain opioid receptor density predicts motor cortex stimulation efficacy for chronic pain. Objective: Innovations in physics and computing technology over the past two decades have provided a powerful means of exploring the overall structure and function of the brain using a range of computerised brain imaging technologies BITs.

These technologies offer the means to elucidate the patterns of pathophysiology underlying mental illness. The aim of this paper is to explore the current status and some of the future directions in the application of BITs to psychiatry.

You will need to change into a hospital gown. This is to prevent artifacts appearing on the final images and to comply with safety regulations related to the strong magnetic field. Guidelines about eating and drinking before an MRI vary between specific exams and facilities. Take food and medications as usual unless your doctor tells you otherwise. Some MRI exams use an injection of contrast material. The doctor may ask if you have asthma or allergies to contrast material, drugs, food, or the environment.

MRI exams commonly use a contrast material called gadolinium. Doctors can use gadolinium in patients who are allergic to iodine contrast. A patient is much less likely to be allergic to gadolinium than to iodine contrast. However, even if the patient has a known allergy to gadolinium, it may be possible to use it after appropriate pre-medication.

Tell the technologist or radiologist if you have any serious health problems or recent surgeries. Some conditions, such as severe kidney disease, may mean that you cannot safely receive gadolinium. You may need a blood test to confirm your kidneys are functioning normally. Women should always tell their doctor and technologist if they are pregnant.

MRI has been used since the s with no reports of any ill effects on pregnant women or their unborn babies. However, the baby will be in a strong magnetic field.

Therefore, pregnant women should not have an MRI in the first trimester unless the benefit of the exam clearly outweighs any potential risks. Pregnant women should not receive gadolinium contrast unless absolutely necessary. Leave all jewelry and other accessories at home or remove them prior to the MRI scan. Metal and electronic items are not allowed in the exam room.

They can interfere with the magnetic field of the MRI unit, cause burns, or become harmful projectiles. These items include:. In most cases, an MRI exam is safe for patients with metal implants, except for a few types. People with the following implants may not be scanned and should not enter the MRI scanning area without first being evaluated for safety:.

Tell the technologist if you have medical or electronic devices in your body. These devices may interfere with the exam or pose a risk. Many implanted devices will have a pamphlet explaining the MRI risks for that device. If you have the pamphlet, bring it to the attention of the scheduler before the exam. MRI cannot be performed without confirmation and documentation of the type of implant and MRI compatibility. You should also bring any pamphlet to your exam in case the radiologist or technologist has any questions.

If there is any question, an x-ray can detect and identify any metal objects. Metal objects used in orthopedic surgery generally pose no risk during MRI. However, a recently placed artificial joint may require the use of a different imaging exam. Tell the technologist or radiologist about any shrapnel, bullets, or other metal that may be in your body. Foreign bodies near and especially lodged in the eyes are very important because they may move or heat up during the scan and cause blindness.

Dyes used in tattoos may contain iron and could heat up during an MRI scan. This is rare. The magnetic field will usually not affect tooth fillings, braces, eyeshadows, and other cosmetics.

However, these items may distort images of the facial area or brain. Tell the radiologist about them. The traditional MRI unit is a large cylinder-shaped tube surrounded by a circular magnet.

You will lie on a table that slides into a tunnel towards the center of the magnet. Some MRI units, called short-bore systems , are designed so that the magnet does not completely surround you. Some newer MRI machines have a larger diameter bore, which can be more comfortable for larger patients or those with claustrophobia.

They are especially helpful for examining larger patients or those with claustrophobia. Open MRI units can provide high quality images for many types of exams. Open MRI may not be used for certain exams. To get the highest quality MRI results, your child will need to lie still during the scan.

For this reason, sedation may be needed, especially for babies and young kids, who often have trouble staying still for the test. Sedation is also helpful for kids who have trouble relaxing in an enclosed space claustrophobia. Sedation medicines usually are given through an intravenous IV line small tube in a vein to help a child stay asleep during the entire test. If your child will be sedated, food and liquids will be stopped at a certain point before the MRI to allow the stomach to empty.

It's important to notify the MRI technician of any illness, allergy, previous drug reactions, or pregnancy. You can stay in the MRI room with your child until the test begins, and some centers let parents stay throughout the test.

Otherwise, you'll join the technician in an outer room or be asked to stay in a waiting room. An MRI of the brain usually takes minutes to perform.

Your child will lie on the movable scanning table while the technologist places him or her into position. A special plastic device called a coil may be placed around your child's head.

The table will slide into the tunnel and the technician will take images of the head. Each scan takes a few minutes. To detect specific problems, your child may be given a contrast solution through an IV. The solution is painless as it goes into the vein. The contrast highlights certain areas of the brain, such as blood vessels, so doctors can see more detail in specific areas.

The technician will ask if your child is allergic to any medications or food before the contrast solution is given.