Published on March 23rd, 2015 | by Theo Arvanitis0
How to know when “thinking goes wrong”
The brain is an amazing organ. It controls many of the functions of the human body – but it is also the organ that processes the information that allows us to understand things – including itself. It is also the last part of the human body to be fully understood. That is, in part, due to it being protected within the skull, but also because of the complexity of its operation. However, recent developments in biomedical imaging techniques are giving us new insight into how it works, how it goes wrong and how we go about fixing it.
Understanding how the body works is a prerequisite to understanding how it goes wrong and therefore how to treat it. Historically, diagnosis relied on the symptoms of disease and relating them back to the underlying cause. As our understanding of biological function increases so does the desire to diagnose the causes more directly. This quest has taken doctors from measuring outside signs to looking inside the body, the organ, and even the chemistry that powers the organ. This path meant that they had to understand systems and how they operated. All of this has led to the increasing use of imaging techniques that allowed doctors to directly see how the organ worked inside the patient.
When it comes to understanding the brain, the move to imaging has been the breakthrough. The distributed and integrated way the brain works means that the clinician has to measure many factors across the brain to see what is wrong. The first technique to see inside the skull was an early example of digital health – computed tomography (CT). In this technique, the head is X-rayed from many angles and the data collected analysed by an algorithm that can generate a density map of the brain. It is mainly used to diagnose trauma from head injuries, but can be augmented by using contrast dyes to measure blood flow. The data gathered and imaged can be visualised as “slices” or built into a 3D image of the brain.
These days, the main technique used to analyse brain function is magnetic resonance imaging and it many derivatives. It is based on the nuclear magnetic resonance phenomenon, where a combination of magnetic fields and radio waves can problem the state of individual atoms. As with CT, the raw data must be collected from many perspectives and combined into an image of the brain. However, because of the physics involved, a lot more information can be extracted. Magnetic resonance imaging (MRI) can measure the density of chemical constituents inside the body, its biochemical composition at a particular point (or map a particular biochemical entity), and hence give use information on the intricacies of an organs structure or even function. Thus, each individual magnetic resonance imaging based technique can give insight into how the brain works – or goes wrong. It is the 3 dimensional maps of these insights and their combination that can tell a clinician where, for example, reduced blood-flow can cause deterioration in function, where a tumour is and what sort of tumour it is.
The biomedical imaging techniques needed to gain insight into the brain are as complicated as the brain itself – and the ways the raw data must be manipulated and analysed to give meaningful insight are constantly developing, enabled by increased computing power and cleverer algorithms. As the imaging techniques have developed, and given us greater understanding of how the brain functions, so we have asked more of imaging. This area has developed fast but is still developing and we can expect much more insight into our own brains in the future.