Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging purposes, depending on the target process within the body.
A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant (cancerous) tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and secondary tumors, which most commonly have spread from tumors located outside the brain, known as brain metastasis tumors. All types of brain tumors may produce symptoms that vary depending on the size of the tumor and the part of the brain that is involved. Where symptoms exist, they may include headaches, seizures, problems with vision, vomiting and mental changes. Other symptoms may include difficulty walking, speaking, with sensations, or unconsciousness.
A head injury is any injury that results in trauma to the skull or brain. The terms traumatic brain injury and head injury are often used interchangeably in the medical literature. Because head injuries cover such a broad scope of injuries, there are many causes—including accidents, falls, physical assault, or traffic accidents—that can cause head injuries.
A computed tomography scan is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or radiology technologists.
Headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches.
A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include loss of consciousness; memory loss; headaches; difficulty with thinking, concentration, or balance; nausea; blurred vision; dizziness; sleep disturbances, and mood changes. Any of these symptoms may begin immediately, or appear days after the injury. Concussion should be suspected if a person indirectly or directly hits their head and experiences any of the symptoms of concussion. Symptoms of a concussion may be delayed by 1–2 days after the accident. It is not unusual for symptoms to last 2 weeks in adults and 4 weeks in children. Fewer than 10% of sports-related concussions among children are associated with loss of consciousness.
Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain. Symptoms may include a severe headache of rapid onset, vomiting, decreased level of consciousness, fever, weakness, numbness, and sometimes seizures. Neck stiffness or neck pain are also relatively common. In about a quarter of people a small bleed with resolving symptoms occurs within a month of a larger bleed.
Intracranial hemorrhage (ICH), also known as intracranial bleed, is bleeding within the skull. Subtypes are intracerebral bleeds, subarachnoid bleeds, epidural bleeds, and subdural bleeds.
Epidural hematoma is when bleeding occurs between the tough outer membrane covering the brain and the skull. When this condition occurs in the spinal canal, it is known as a spinal epidural hematoma.
Neuroimaging is the use of quantitative (computational) techniques to study the structure and function of the central nervous system, developed as an objective way of scientifically studying the healthy human brain in a non-invasive manner. Increasingly it is also being used for quantitative research studies of brain disease and psychiatric illness. Neuroimaging is highly multidisciplinary involving neuroscience, computer science, psychology and statistics, and is not a medical specialty. Neuroimaging is sometimes confused with neuroradiology.
A subdural hygroma (SDG) is a collection of cerebrospinal fluid (CSF), without blood, located under the dural membrane of the brain. Most subdural hygromas are believed to be derived from chronic subdural hematomas. They are commonly seen in elderly people after minor trauma but can also be seen in children following infection or trauma. One of the common causes of subdural hygroma is a sudden decrease in pressure as a result of placing a ventricular shunt. This can lead to leakage of CSF into the subdural space especially in cases with moderate to severe brain atrophy. In these cases the symptoms such as mild fever, headache, drowsiness and confusion can be seen, which are relieved by draining this subdural fluid.
Computed tomography angiography is a computed tomography technique used for angiography—the visualization of arteries and veins—throughout the human body. Using contrast injected into the blood vessels, images are created to look for blockages, aneurysms, dissections, and stenosis. CTA can be used to visualize the vessels of the heart, the aorta and other large blood vessels, the lungs, the kidneys, the head and neck, and the arms and legs. CTA can also be used to localise arterial or venous bleed of the gastrointestinal system.
Cerebral venous sinus thrombosis (CVST), cerebral venous and sinus thrombosis or cerebral venous thrombosis (CVT), is the presence of a blood clot in the dural venous sinuses, the cerebral veins, or both. Symptoms may include severe headache, visual symptoms, any of the symptoms of stroke such as weakness of the face and limbs on one side of the body, and seizures, which occur in around 40% of patients.
Midline shift is a shift of the brain past its center line. The sign may be evident on neuroimaging such as CT scanning. The sign is considered ominous because it is commonly associated with a distortion of the brain stem that can cause serious dysfunction evidenced by abnormal posturing and failure of the pupils to constrict in response to light. Midline shift is often associated with high intracranial pressure (ICP), which can be deadly. In fact, midline shift is a measure of ICP; presence of the former is an indication of the latter. Presence of midline shift is an indication for neurosurgeons to take measures to monitor and control ICP. Immediate surgery may be indicated when there is a midline shift of over 5 mm. The sign can be caused by conditions including traumatic brain injury, stroke, hematoma, or birth deformity that leads to a raised intracranial pressure.
A cerebrospinal fluid leak is a medical condition where the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord leaks out of one or more holes or tears in the dura mater. A CSF leak is classed as either spontaneous (primary), having no known cause, or nonspontaneous (secondary) where it is attributed to an underlying condition. Causes of a primary CSF leak are those of trauma including from an accident or intentional injury, or arising from a medical intervention known as iatrogenic. A basilar skull fracture as a cause can give the sign of CSF leakage from the ear nose or mouth. A lumbar puncture can give the symptom of a post-dural-puncture headache.
Magnetic resonance imaging of the brain uses magnetic resonance imaging (MRI) to produce high quality two-dimensional or three-dimensional images of the brain and brainstem as well as the cerebellum without the use of ionizing radiation (X-rays) or radioactive tracers.
A sports-related traumatic brain injury is a serious accident which may lead to significant morbidity or mortality. Traumatic brain injury (TBI) in sports are usually a result of physical contact with another person or stationary object, These sports may include boxing, gridiron football, field/ice hockey, lacrosse, martial arts, rugby, soccer, wrestling, auto racing, cycling, equestrian, rollerblading, skateboarding, skiing or snowboarding.
Spinal cord injury without radiographic abnormality (SCIWORA) is symptoms of a spinal cord injury (SCI) with no evidence of injury to the spinal column on X-rays or CT scan. Symptoms may include numbness, weakness, abnormal reflexes, or loss of bladder or bowel control. Neck or back pain is also common. Symptoms may be brief or persistent. Some do not develop symptoms until a few days after the injury.
A central nervous system tumor is an abnormal growth of cells from the tissues of the brain or spinal cord. CNS tumor is a generic term encompassing over 120 distinct tumor types. Common symptoms of CNS tumors include vomiting, headache, changes in vision, nausea, and seizures. A CNS tumor can be detected and classified via neurological examination, medical imaging, such as x-ray imaging, magnetic resonance imaging (MRI) or computed tomography (CT), or after analysis of a biopsy.
Alan Edward Zimmer, M.D. was an American neuroradiologist, specializing in duplex neurovascular and magnetic resonance imaging (MRI). In the 1960s, Zimmer helped bring early neuroradiology methological advancements developed in Sweden to radiologists in the United States. He also conducted early research related to the emerging technologies of computer axial tomography and MRI as these procedures began to revolutionize radiology in the 1970s and '80s. As New Jersey’s senior neuroradiologist, Zimmer was consulted frequently by physicians, hospitals, and the courts to help diagnosis injuries and disease related to the head, neck, and spine. Zimmer was chief of neuroradiology at the University of Medicine and Dentistry of New Jersey (UMDNJ) from 1983 until his death.
