We will be looking at five diseases of the brain and the role advanced imaging plays in their diagnosis.
Advanced Imagining Defined
The types of advanced internal scanning machines used in diagnosing diseases of the brain are computerized tomography (CT) and magnetic resonance imaging (MRI). Information found by these scans explains that the interpretation of CT or MRI images of the brain aid physicians in forming a diagnosis.
How CT Scans Work
Using x-rays a CT scan produces a 2-D image of a targeted section of the body. CT images are created using digital x-ray detectors rather than film. Beams of radiation entering the body are turned into images using a mathematical algorithm. Click here to learn more about CT scans and MRIs
How an MRI Works
MRI machines use radio waves and a magnetic field to create more detailed images than a CT scan. The images produced are 2-D, but there are MRI units that produce 3-D images. The image is the result of the magnetic field pulling hydrogen protons within the body into alignment. The radio waves then cause the nuclei of the protons to vibrate.
Brain Abscess
A brain abscess is a localized infection of the brain. A brain abscess is usually a bacterial infection. An abscess exerts pressure on the brain possibly causing headaches and nausea. Other possible symptoms of a brain abscess include disorientation, excessive fatigue, and seizures. Either computerized tomography or magnetic resonance imaging is used to detected abscesses of the brain. Images of brain abscesses appear as a spot or spots on the brain.
Concussion
As opposed to being viral or bacterial in origin concussion is the result of the violent shaking of or a blow (trauma) to the head. A concussion occurs when the brain collides with the skull. A concussion may cause amnesia, impaired balance, tinnitus, nausea, and vomiting. A loss of consciousness is also possible. An MRI or CT scan may be ordered to check the brain for bleeding.
Brain Aneurysm
When an artery in the brain begins to swell because of weakening in its wall the result is an aneurysm. If the pressure should cause the aneurysm to rupture a stroke will result. When an aneurysm is suspected the initial images of the brain are usually taken using a CT scanner. The use of an MRI angiography is also possible. Angiography focuses on the arteries. A very painful headache, stiff neck, drooping eyelids, nausea, and vomiting can be indicative of an aneurysm. An aneurysm can also affect eyesight causing blurred vision, double vision, and light sensitivity.
Encephalitis
Generally, the result of viral infection encephalitis causes the brain to swell. Encephalitis and meningitis can occur together resulting in a condition known as meningoencephalitis. If encephalitis is suspected an MRI may be ordered. Any swelling or other physical indicators of encephalitis will be detected by magnetic resonance imaging. Encephalitis shares the same symptoms that the brain diseases already listed have in common with the addition of personality changes and seizures.
Brain tumours
The result of excess tissue developing on the brain a tumour puts pressure on the brain. Although they can be cancerous the presence of a tumour does not necessarily mean the presence of brain cancer. Headaches which may be aggravated by activity are symptomatic of a brain tumour. Brain tumours can also adversely affect memory, sleep, and cause seizures. Seizures, nausea, and vomiting are also possible with a brain tumour. Brain tumours are detected using computerized tomography, magnetic resonance imaging, and an MRI angiogram.