Giant Cell Arteritis – How does the doctor make the diagnosis?
The definitive diagnosis is usually made by a rheumatologist—a specialist in inflammatory diseases of the blood vessels and joints. This process typically includes a detailed discussion about the patient’s symptoms over time, their medical history, and any relevant family history. If Giant Cell Arteritis is suspected, the first step is usually a blood test. Specifically, doctors determine the erythrocyte sedimentation rate and C-reactive protein levels. If these markers are elevated, it supports the suspicion of inflammation in the body. Additional tests are then used to determine the exact cause.
Can't the doctor just tell from the symptoms whether it is Giant Cell Arteritis?
Unfortunately, symptoms alone are not enough to make a definitive diagnosis. The symptoms of Giant Cell Arteritis are often nonspecific: they may appear suddenly, come and go, evolve over time, or resemble those of other conditions. You can learn more about typical symptoms here. Even though some signs are characteristic of this autoimmune disease, other possible causes must be ruled out first, such as:
- Infections
- Cancer or tumors
- Other types of vasculitis, e.g. Takayasu arteritis or inflammation of small and medium-sized vessels
- Non-inflammatory circulatory problems affecting the optic nerve
What methods are used to detect Giant Cell Arteritis?
To confirm or rule out the diagnosis, the doctor may use a combination of so-called histopathological and imaging techniques:
Tissue sample from the temporal artery (Temporal Artery Biopsy)
During a temporal artery biopsy, the doctor removes a small piece of tissue from the temporal artery under local anesthesia. This sample is then examined under a microscope by a pathologist to check for signs of inflammation. In most cases, this method reliably confirms whether Giant Cell Arteritis is present. However, in those patients whose disease primarily affects other large blood vessels, the tissue sample may appear normal, even if the condition is present.
Biopsy of the temporal arteries
Fundus Examination (Ophthalmoscopy)
Using a special magnifying lens, the ophthalmologist examines the back of the eye (the fundus). Inflammatory changes—such as swelling or hemorrhages—can offer clues that point to Giant Cell Arteritis.
Ophthalmoscopy (Fundus Examination)
Color Doppler Ultrasound (CDUS/CCDS)
This technique allows the doctor to detect changes in the walls of blood vessels. It also visualizes blood flow in color, making it possible to quickly identify even small areas of inflammation or narrowing.
Color Doppler Ultrasound (CDUS) / Color-Coded Duplex Sonography (CCDS)
Magnetic Resonance Imaging (MRI)
MRI produces precise images of the blood vessels and can detect even minimal changes. Important: All metallic objects must be removed before the examination. If you have an implant, such as a pacemaker, or another medical device in your body, make sure to inform your doctor in advance. Tattoos should also be mentioned, as they can occasionally affect image quality.
Magnetic Resonance Imaging (MRI)
Positron Emission Tomography (PET)
This examination is used less often. The patient is given a mildly radioactive contrast agent that accumulates specifically in inflamed tissue. When combined with computed tomography (CT), PET allows doctors to see parts of the blood vessels that other tests might not clearly show.