Further Investigations: Tests and Imaging

August 2017

There are no specific tests for the diagnosis of Alzheimer's disease.

Therefore, the principle is to rule out other conditions and to diagnose Alzheimer's by exclusion.

Initial Investigations


Initially, blood tests are performed to exclude anaemia, kidney or liver problems, hypothyroidism, vitamin deficiency and infection. A chest x-ray and urine analysis may also be carried out.

In some cases, further investigations such as a drug screen or HIV test may be necessary.

Brain imaging


Brain imaging is recommended for any recent dementia.

Computerised Tomography (CT)


The first imaging technique would be a CT scan.

CT is useful to show any thinning of brain tissue, brain tumours or hydrocephalus (excess fluid around the brain).

Magnetic Resonance Imaging (MRI)


  • MRI is preferred to CT and generally required when diagnosis is uncertain
  • MRI offers a more detailed scan so that any loss of brain tissue associated with Alzheimer's disease can be seen
  • Therefore, MRI can highlight very early anomalies before people will develop the disease
  • MRI also enables doctors to follow the disease's progress

SPECT and PET


When a diagnosis of dementia is more difficult, a Single Photon Emission Computed Tomography (SPECT) or a Positron Emission Tomography (PET) is recommended.

Related


El diagnóstico por la imagen
El diagnóstico por la imagen
Latest update on May 28, 2010 at 11:54 AM by N.T.
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