Mary Spiers, Ph.D.
If you have a character with a neurological disorder in your story, odds are you’re considering a scene in which the results of a brain scan will be interpreted.
Writers who want to mention or show a brain scan may wonder what types of imaging are appropriate to include for their character’s disorder. If you simply Google “brain imaging methods” you’ll find a dizzying number of possible options.
The latest developments in brain imaging have resulted in a number of experimental high-tech options.
However, if your story is set in the present day, these powerful imaging methods, like PET scans, DTI and fMRIs are not typically used in day-to-day neurological practice. They may either be too expensive or not necessary to make a diagnosis. As of now, they're used more in research aimed at discovering how the brain works.
Some of the newer imaging methods show a lot of promise, and they’re cool visually, so if your story is set in the future then you may choose to show some of these newer methods.
Below, I've compiled a cheat sheet listing the most common imaging methods used today and the reason each would be used.
If you have a character with a neurological disorder in your story, odds are you’re considering a scene in which the results of a brain scan will be interpreted.
Writers who want to mention or show a brain scan may wonder what types of imaging are appropriate to include for their character’s disorder. If you simply Google “brain imaging methods” you’ll find a dizzying number of possible options.
The latest developments in brain imaging have resulted in a number of experimental high-tech options.
However, if your story is set in the present day, these powerful imaging methods, like PET scans, DTI and fMRIs are not typically used in day-to-day neurological practice. They may either be too expensive or not necessary to make a diagnosis. As of now, they're used more in research aimed at discovering how the brain works.
Some of the newer imaging methods show a lot of promise, and they’re cool visually, so if your story is set in the future then you may choose to show some of these newer methods.
Below, I've compiled a cheat sheet listing the most common imaging methods used today and the reason each would be used.
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The Writer's Brain Lab
Brain Scan "Cheat Sheet"
First, there are 2 main types of imaging methods: Structural and Functional.
Neurologists are often interested in looking at the STRUCTURE of the brain to see if everything is in place, to look for fractures, lesions (holes), bleeds, tumors or brain tissue death. To find out if a physical problem exists (that is big enough to be seen) and where the problem is the structural methods are used.
At other times it is important to look at the FUNCTION of the brain to examine how it is working, by analyzing electrical neuronal communication, biochemistry or blood and oxygen flow to the brain.
Imaging is very useful but will not diagnose everything nor is it able to read minds or determine if a person is "smart" in some area. Many times brain scans and other tests are ordered to help “rule out” problems.
For example, there is no current readily available imaging method to diagnose Alzheimer’s disease. However, tests are run to rule out strokes, tumors or other types of dementia. The neurologist will examine the patient, and will often involve a neuropsychologist to help in examining and testing the patient's memory and cognition. The diagnosis is then made with the help of imaging as well as other examinations and neuropsychological methods.
Following are descriptions of the most common imaging methods and some of the more common reasons you would use them for your story character.
STRUCTURAL Imaging
CT or CAT (Computed Axial tomography) scans combine many X-rays in order to see the brain in either 2D or 3D. CAT scans of the brain do not show very small brain changes. This is often the first scan that may be used in an emergency situation. This was one of the first brain imaging technologies to be put into common clinical use.
Common uses:
•Tumor diagnosis
•Stroke diagnosis - death of tissue and/or bleeding
•Skull fracture diagnosis
MRI (Magnetic Resonance Imaging) uses a powerful magnetic field (patients with metal implants cannot use this) to produce high-resolution 2D or 3D images of the brain. MRI costs more than a CT scan but is now used in many hospitals because the better resolution will uncover finer grained issues.
Common uses:
•Tumor diagnosis or to rule out if a tumor is present
•Traumatic Brain Injury (TBI) shows
-“bruising of the brain”, bleeds
- small (not microscopic) areas of damage
•Multiple Sclerosis - brain and spinal cord lesions
• Dementia - to examine brain size, to see if all or part of the brain has “shrunk”.
- Ex. Parkinson’s disease – changes in the substania nigra
• Seizures - to look for seizure causes
-lesions, tumors or tissue irregularities
•Stroke diagnosis - reveals problems of tissue death earlier than CT scans. TIA
(transient ischemic attack, aka: mini-stroke).
Cerebral Angiogram (Arteriogram) details the structure of the arteries within the neck and brain to see if they are malformed, narrowed or ballooned (aneurysm). A dye must be inserted through a catheter (groin) to see the arteries in better contrast.
Common uses:
•Stroke risk - to look for "narrowing of the arteries" or a clot that may cause or
has caused a stroke.
•Congenital problem - to look for ateriorvascular malformations (AVM) that can
cause weak spots in blood vessels.
•Severe Headaches - to look for vascular causes of headaches, or inflammation.
•Tumor - to examine the blood supply to a tumor before operating.
FUNCTIONAL Imaging
EEG (Electroencephalography) monitors the electrical activity of the brain through electrodes placed on the scalp. In some cases electrodes are implanted through the skull (depth electrodes) to overcome the interference of the skull.
Common uses:
•Seizure diagnosis: to look for the “focus” (area where the seizure starts)
•Coma: to monitor brain activity to determine level of alertness/consciousness
•Brain death: to determine loss of brain activity
•Sleep disorders: in this case the EEG is called a
PSG (Polysomnogram) and is monitored through the night.
Ultrasound (Sonography, Transcranial Doppler) uses sound waves to measure fluids. This is usually the speed and volume of blood flow (hemodynamics) of the carotid arteries in the neck that supply blood to the brain. Sometimes it may be used to measure the Cerebral Spinal Fluid that surrounds the brain and spinal cord. Whereas Arteriogram measures structure, the doppler measures function for some of the same problems, and so may be used together. Since the bone of the skull interferes with readings, the measurement is taken at places where the arteries enter the skull or where bone is thinner, or at times when the skull is "open" (as in surgery, or for infants). This produces very detailed images.
Common uses:
•Stroke risk - to look for "narrowing of the arteries" or a clot that may cause or
have caused a stroke.
• Hydrocephalous - to look for reasons for swelling of the brain in infants.
fMRI (functional Magnetic Resonance Imaging) is used to help map functional areas of the brain as they relate to behavior such as speech and language and memory. By asking a person to perform a task while imaging the brain, the functional area for that ability (for that person) can be determined. As of late 2014, fMRI is not often used to diagnose problems. It is very expensive and requires a number of support personnel to operate, process and interpret the findings. As the technology becomes more widely used, fMRI may be more commonly used in treatment.
•Stroke treatment - to map out recovery (e.g. speech processing)
•Traumatic Brain Injury (TBI) treatment - mapping out recovery
•Tumor surgery -to map out functional areas before or during surgery
•Epilepsy (seizures) - to help map out areas of the seizure focus (not yet in
common practice) and to map out functional areas that may be
affected if surgery for seizures is needed.
Some final points:
•Keep in mind that imaging methods are one of many tools that physicians will use to aid in diagnosis along with history and physical, other medical tests, and neuropsychological (cognitive, intellectual and behavioral) assessment.
•Sometimes more than one imaging method may be appropriate (e.g. a CAT scan or MRI for stroke), or several methods may be used together to get a picture of both structure and function (MRI, carotid ultrasound & cerebral angiogram for stroke).
•If you want to include a static picture of a "brain scan" it will need to fit with the structural methods used (e.g. MRI). If you are depicting a changing image (e.g. fMRI) then this will be one of the functional imaging methods.
• I've included common brain imaging methods in clinical use that will cover most of the more common disorders that writers encounter. New imaging methods are continually being developed, but it takes some time for them to be widely adopted in clinical practice. If you want to use a new method or are writing about a more rare disorder, fact check with a practicing neurologist in a hospital to see if the imaging method you want to include is currently used.
Brain Scan "Cheat Sheet"
First, there are 2 main types of imaging methods: Structural and Functional.
Neurologists are often interested in looking at the STRUCTURE of the brain to see if everything is in place, to look for fractures, lesions (holes), bleeds, tumors or brain tissue death. To find out if a physical problem exists (that is big enough to be seen) and where the problem is the structural methods are used.
At other times it is important to look at the FUNCTION of the brain to examine how it is working, by analyzing electrical neuronal communication, biochemistry or blood and oxygen flow to the brain.
Imaging is very useful but will not diagnose everything nor is it able to read minds or determine if a person is "smart" in some area. Many times brain scans and other tests are ordered to help “rule out” problems.
For example, there is no current readily available imaging method to diagnose Alzheimer’s disease. However, tests are run to rule out strokes, tumors or other types of dementia. The neurologist will examine the patient, and will often involve a neuropsychologist to help in examining and testing the patient's memory and cognition. The diagnosis is then made with the help of imaging as well as other examinations and neuropsychological methods.
Following are descriptions of the most common imaging methods and some of the more common reasons you would use them for your story character.
STRUCTURAL Imaging
CT or CAT (Computed Axial tomography) scans combine many X-rays in order to see the brain in either 2D or 3D. CAT scans of the brain do not show very small brain changes. This is often the first scan that may be used in an emergency situation. This was one of the first brain imaging technologies to be put into common clinical use.
Common uses:
•Tumor diagnosis
•Stroke diagnosis - death of tissue and/or bleeding
•Skull fracture diagnosis
MRI (Magnetic Resonance Imaging) uses a powerful magnetic field (patients with metal implants cannot use this) to produce high-resolution 2D or 3D images of the brain. MRI costs more than a CT scan but is now used in many hospitals because the better resolution will uncover finer grained issues.
Common uses:
•Tumor diagnosis or to rule out if a tumor is present
•Traumatic Brain Injury (TBI) shows
-“bruising of the brain”, bleeds
- small (not microscopic) areas of damage
•Multiple Sclerosis - brain and spinal cord lesions
• Dementia - to examine brain size, to see if all or part of the brain has “shrunk”.
- Ex. Parkinson’s disease – changes in the substania nigra
• Seizures - to look for seizure causes
-lesions, tumors or tissue irregularities
•Stroke diagnosis - reveals problems of tissue death earlier than CT scans. TIA
(transient ischemic attack, aka: mini-stroke).
Cerebral Angiogram (Arteriogram) details the structure of the arteries within the neck and brain to see if they are malformed, narrowed or ballooned (aneurysm). A dye must be inserted through a catheter (groin) to see the arteries in better contrast.
Common uses:
•Stroke risk - to look for "narrowing of the arteries" or a clot that may cause or
has caused a stroke.
•Congenital problem - to look for ateriorvascular malformations (AVM) that can
cause weak spots in blood vessels.
•Severe Headaches - to look for vascular causes of headaches, or inflammation.
•Tumor - to examine the blood supply to a tumor before operating.
FUNCTIONAL Imaging
EEG (Electroencephalography) monitors the electrical activity of the brain through electrodes placed on the scalp. In some cases electrodes are implanted through the skull (depth electrodes) to overcome the interference of the skull.
Common uses:
•Seizure diagnosis: to look for the “focus” (area where the seizure starts)
•Coma: to monitor brain activity to determine level of alertness/consciousness
•Brain death: to determine loss of brain activity
•Sleep disorders: in this case the EEG is called a
PSG (Polysomnogram) and is monitored through the night.
Ultrasound (Sonography, Transcranial Doppler) uses sound waves to measure fluids. This is usually the speed and volume of blood flow (hemodynamics) of the carotid arteries in the neck that supply blood to the brain. Sometimes it may be used to measure the Cerebral Spinal Fluid that surrounds the brain and spinal cord. Whereas Arteriogram measures structure, the doppler measures function for some of the same problems, and so may be used together. Since the bone of the skull interferes with readings, the measurement is taken at places where the arteries enter the skull or where bone is thinner, or at times when the skull is "open" (as in surgery, or for infants). This produces very detailed images.
Common uses:
•Stroke risk - to look for "narrowing of the arteries" or a clot that may cause or
have caused a stroke.
• Hydrocephalous - to look for reasons for swelling of the brain in infants.
fMRI (functional Magnetic Resonance Imaging) is used to help map functional areas of the brain as they relate to behavior such as speech and language and memory. By asking a person to perform a task while imaging the brain, the functional area for that ability (for that person) can be determined. As of late 2014, fMRI is not often used to diagnose problems. It is very expensive and requires a number of support personnel to operate, process and interpret the findings. As the technology becomes more widely used, fMRI may be more commonly used in treatment.
•Stroke treatment - to map out recovery (e.g. speech processing)
•Traumatic Brain Injury (TBI) treatment - mapping out recovery
•Tumor surgery -to map out functional areas before or during surgery
•Epilepsy (seizures) - to help map out areas of the seizure focus (not yet in
common practice) and to map out functional areas that may be
affected if surgery for seizures is needed.
Some final points:
•Keep in mind that imaging methods are one of many tools that physicians will use to aid in diagnosis along with history and physical, other medical tests, and neuropsychological (cognitive, intellectual and behavioral) assessment.
•Sometimes more than one imaging method may be appropriate (e.g. a CAT scan or MRI for stroke), or several methods may be used together to get a picture of both structure and function (MRI, carotid ultrasound & cerebral angiogram for stroke).
•If you want to include a static picture of a "brain scan" it will need to fit with the structural methods used (e.g. MRI). If you are depicting a changing image (e.g. fMRI) then this will be one of the functional imaging methods.
• I've included common brain imaging methods in clinical use that will cover most of the more common disorders that writers encounter. New imaging methods are continually being developed, but it takes some time for them to be widely adopted in clinical practice. If you want to use a new method or are writing about a more rare disorder, fact check with a practicing neurologist in a hospital to see if the imaging method you want to include is currently used.
About the Author: Mary Spiers is a Clinical Neuropsychologist and Writer.
She’s the creator of Neuropsyfi and the Writer’s Brain Lab Blog.
Find out more about Mary Spiers,
submit a story question or follow her on Twitter.
She’s the creator of Neuropsyfi and the Writer’s Brain Lab Blog.
Find out more about Mary Spiers,
submit a story question or follow her on Twitter.