Brain scintigraphy (SPECT): what é and what is it for

Brain scintigraphy, or brain perfusion tomography (SPECT), is a test performed to detect changes in blood circulation and brain function, and is usually performed to assist in the identification or monitoring of degenerative brain diseases, such as Alzheimer's, Parkinson's or tumor, especially when other tests such as magnetic resonance imaging or computed tomography are not enough to confirm the suspicions.

The brain scintigraphy exam is performed with the injection of drugs, known as radiopharmaceuticals, which are capable of fixing in the brain tissue, allowing the formation of images in the device.

What is it for

Brain scintigraphy provides information about blood perfusion and brain function, very useful in situations like:

Search for dementias such as Alzheimer's or Lewy body dementia;
Identify foci of epilepsy;
Evaluate brain tumors;
Assist in the diagnosis of Parkinson's disease or other parkinsonian syndromes such as Huntington's disease;
Assessment of neuropsychiatric diseases such as schizophrenia and depression;
Perform early diagnosis, control and evolution of vascular brain diseases such as stroke and other types of strokes;
Confirm brain death;
Evaluation of traumatic injury, subdural hematomas, abscesses and cases of vascular malformation;
Evaluation of inflammatory lesions such as herpetic encephalitis, systemic lupus erythematosus, Behçet's disease, and HIV-associated encephalopathy.

Many times, brain scintigraphy is requested when there are doubts regarding the diagnosis of a neurological disease, since exams such as magnetic resonance and computed tomography, by showing more structural changes and in the anatomy of brain tissue, may not be enough to clarify some cases.

Which doctor can order the exam

Brain scintigraphy is usually ordered by the neurologist when there is a suspicion of a neurological disease that cannot be confirmed by magnetic resonance imaging or computed tomography.

How it's made

To perform brain scintigraphy, no specific preparation is necessary. On the day of the exam, it is recommended that the patient rest for about 15 to 30 minutes, in a quiet room, to minimize anxiety, to ensure a better quality of the exam.

Next, the radiopharmaceutical, usually Technetium-99m or Thallium, is applied to the patient's vein, who must wait for at least 1 hour until the substance is properly concentrated in the brain, then images can be taken in the appliance for about 40 to 60 minutes. During this period, it is necessary to remain still and lie down, as movement can impair the formation of images.

Next, the patient is released for normal activities. The radiopharmaceuticals used do not usually cause reactions or any harm to the he alth of the person performing the test.