Understanding Medical Imaging with an Example-Neuroimaging

Medical Imaging refers to the process of creating images of various organs of the human body. Medical Imaging is a vital diagnostic tool, helping physicians understand the illness or disease that is affecting a patient by visualizing the structural and functional aspects of various organs. Medical Imaging is also used as a part of treatment and management of many health conditions. The basics of Medical Imaging are rather simple, i.e. the images of the patient’s organs are compared with the normal/conventional images. This comparison helps the physicians to understand the anatomical or physiological differences in the medical images of the patient, i.e. the images help to decode the underlying problem. Medical Imaging is a vast niche and it combines many disciplines of medical science, such as radiology, nuclear medicine, investigative science, thermography, endoscopy, medical photography and microscopy.

Understanding Medical Imaging with an Example: Neuroimaging
There are various branches of Medical Imaging too such as Neuroimaging that is dedicated to directly or indirectly creating images of the body organs that are part of the human nervous system. This helps neurologists to understand the structural, functional or biochemical problems in the brain that are inducing neurological disorders/diseases. Neuroimaging is further categorized into two, broad categories. These are:

  • Structural Imaging—this branch of Medical Imaging deals with the structural composition of the brain. It is used in the diagnosis of large-scale intracranial diseases such as head trauma or tumors.
  • Functional Imaging—this branch of Medical Imaging is used for diagnosing the metabolic diseases affecting the brain. This includes lesions or neurological diseases like Alzheimer's disease. Functional imaging is also used as a neurological evaluation tool in psychology and behavioral studies. Functional Imaging enables to understand how the brain is functioning and identify any parts that might be functioning in an abnormal manner. For instance, functional imaging helps to color code different lobes of the brain, clearly indicating which lobes are showing signs of impaired function.

Popular Medical Imaging Techniques: Brain Imaging
Brain Imaging is considered as a specialty in the niche of Medical Imaging.. Here, imaging studies of the brain are carried out using standard medical imaging methods such as:

Computed Axial Tomography
This is also called a CT scan or CAT Scan (Computed Axial Tomography). Here, x-rays are taken from various angles around the head of the patient. CAT scanning is particularly useful for identifying the extent of damage a serious head injury has induced or other types of brain injuries. CT scanning is based on the principle that different sections of the brain should absorb X-ray beams within a particular range. This range has been calculated after establishing the amount of radioactive absorption different human tissues exhibit when exposed to a steady stream of X-rays. Thus, if any section of the brain seems to absorb more or less than the indicated range, an abnormality is noted and this forms the basis for further investigation. The images created through CAT scanning are essentially cross-sections of various parts of the brain that can be created rather quickly. This is of great importance in cases of serious head injuries where brain damage is always a possible reason for fatality.

Magnetic Resonance Imaging
This medical imaging technique is commonly referred to as MRI. It is among the most recommended imaging technologies that is used in the diagnosis and management of many, serious neurological disorders. During MRI, radio-waves are passed onto the head of the patient. The patient’s head is surrounded by sensors that help to create detailed images of the brain. The entire process is highly computerized and helps neurologists have access to detailed (mapped) brain images. Advancement in this niche has been made in the form of Functional MRI or fMRI that helps to analyze how blood is flowing across various sections of the brain.