Investigations
1st investigations to order
erythrocyte sedimentation rate (ESR)
CRP
computed tomography angiography (CTA)
Test
CTA may be performed with helical scanning and 3D reconstruction. It has high sensitivity and specificity (over 95%) for the diagnosis of Takayasu's arteritis. Catheter angiogram is not recommended due to its invasive nature, unless required prior to revascularisation procedures.[25][28][30][Figure caption and citation for the preceding image starts]: Computed tomography angiogram, with 3D reconstruction of the aortic arch and major vessels, showing proximal occlusion of the left subclavian artery and patent left vertebral artery distal to the occlusion (left vertebral steal syndrome)From the collection of Kenneth J. Warrington, MD [Citation ends].
[Figure caption and citation for the preceding image starts]: Computed tomography angiogram, with 3D reconstruction of the aortic arch and major vessels, showing narrowing of the left common carotid artery and left subclavian arteryFrom the collection of Kenneth J. Warrington, MD [Citation ends].
[Figure caption and citation for the preceding image starts]: Computed tomography angiogram with 3D reconstruction showing bilateral renal artery stenosisFrom the collection of Kenneth J. Warrington, MD [Citation ends].
Result
segmental narrowing or occlusion, occasionally dilation, of affected vessels; aortic aneurysms may be seen; thickening of vessel walls may be seen but is of uncertain significance
magnetic resonance angiography (MRA)
Test
MRA is used to identify arterial involvement, and it may be useful in the assessment of disease activity, with vessel wall thickening and oedema thought to reflect active disease.[31][Figure caption and citation for the preceding image starts]: Magnetic resonance angiogram of the aortic arch and major vessels showing occlusion of bilateral subclavian arteries; left common carotid artery has small diameter; proximal vertebral arteries are not identifiedFrom the collection of Kenneth J. Warrington, MD [Citation ends].
Result
segmental narrowing, occlusion, or dilation of involved arteries; vessel wall inflammation may be detectable
Investigations to consider
Doppler ultrasound
Test
Particularly useful in the early vascular evaluation of patients with suspected Takayasu's arteritis, as it is a non-invasive procedure. Abdominal ultrasound may reveal mesenteric or renal artery stenosis, and transthoracic/trans-oesophageal studies can detect abnormalities in the upper aorta and subclavian and carotid arteries.[32]
Result
segmental narrowing, occlusion, and/or dilation of involved arteries
positron emission tomography with radiolabelled fluorodeoxyglucose (PET-FDG)
Test
Can be used to identify inflammation in the large arteries and is therefore a useful technique to establish diagnosis. PET-FDG can also be used for assessing disease activity over time.[25][26]
PET-FDG performs comparably to CTA for the detection of aortitis.[25][33]
Result
may show increased uptake in actively inflamed arterial segments
Use of this content is subject to our disclaimer