Takayasu arteritis is a chronic granulomatous large vessel vasculitis predominantly affecting the aorta and its primary branches, occurring in young women. Also known as 'pulseless disease' because stenosis/occlusion of upper extremity arteries leads to pulse loss. It occurs predominantly between ages 10-40, with a female-to-male ratio of 8-9:1. Most common in East Asia, India, and Latin America, with worldwide incidence of 1-2/million/year. CT/MR angiography characteristically shows concentric wall thickening (>3 mm) of the aorta and branches, stenosis, occlusion, and aneurysm formation. Pulmonary artery involvement (50%) and coronary artery involvement (10-30%) are important complications. The disease progresses in two phases: active inflammatory phase and chronic fibrotic phase.
Age Range
10-40
Peak Age
25
Gender
Female predominant
Prevalence
Rare
Autoimmune mechanisms play a role in the pathogenesis of Takayasu arteritis. On a background of genetic susceptibility (strong HLA-B*52 association), a yet unidentified triggering antigen activates dendritic cells in the vasa vasorum. CD4+ and CD8+ T-lymphocytes infiltrate the adventitia and media of the arterial wall → granuloma formation → medial smooth muscle necrosis and elastic fiber destruction → intimal hyperplasia (fibrous proliferation) → luminal narrowing. In the inflammatory phase, arterial wall thickening and edema are prominent — seen as T2 hyperintensity and enhancement on MRI. In the chronic phase, fibrosis and calcification develop → wall thickening becomes permanent but enhancement decreases. Inflammatory weakening of the aortic wall also predisposes to aneurysm formation — particularly in thoracic and abdominal aorta. Stenosis and occlusion reduce blood flow to organs: subclavian stenosis → upper extremity ischemia/pulselessness; carotid/vertebral stenosis → cerebrovascular ischemia; renal artery stenosis → renovascular hypertension; mesenteric stenosis → intestinal ischemia. Pulmonary arterial hypertension may develop in pulmonary artery involvement.
Long-segment homogeneous hypoechoic concentric wall thickening in the carotid or subclavian artery — named 'Macaroni sign' because it resembles a macaroni stick. This finding reflects arterial wall thickening due to granulomatous inflammation and edema in the active inflammatory phase of Takayasu arteritis. Differs from the halo sign in GCA by longer segment involvement and more prominent wall thickness. Easy and non-invasive assessment with ultrasound.
Concentric wall thickening (>3 mm, sometimes >10 mm) and multiple long-segment stenosis/occlusion of the aorta and primary branches (subclavian, carotid, renal, iliac) on CT angiography. Wall thickening is soft tissue density in active phase, may be calcified in chronic phase. Stenosis typically shows ostial/proximal segment involvement. Rich collateral circulation develops in occlusion. According to Numano classification: Type I (aortic arch branches), Type II (descending thoracic/abdominal aorta), Type III (combined), Type IV (pulmonary artery), Type V (entire aorta). Late-phase (dual-phase) wall enhancement indicates active inflammation.
Report Sentence
Concentric wall thickening and multiple long-segment stenosis/occlusion of the aorta and primary branches on CT angiography, consistent with Takayasu arteritis.
Hyperintense signal on T2/STIR in aorta and branch artery walls in the active inflammatory phase on MRI — indicator of wall edema and active granulomatous inflammation. Black-blood T2 STIR sequence clearly images wall edema by suppressing blood signal. T2 hyperintensity is the most reliable MR indicator of active disease activity and is used for monitoring treatment response. Mural enhancement on contrast T1 also supports active inflammation. In the chronic fibrotic phase, T2 signal normalizes and enhancement decreases — but wall thickening may persist.
Report Sentence
Hyperintense edema on T2/STIR and prominent mural enhancement on contrast T1 in the aortic wall on MRI, consistent with active Takayasu arteritis.
Diffuse increased FDG uptake in the aorta and branches on FDG PET-CT — metabolic marker of active vascular inflammation. Aortic wall uptake above liver level (visual grade ≥2) is considered significant. Uptake pattern in Takayasu is typically diffuse and covers large segments of the aorta — similar to GCA but more extensive. PET-CT is equivalent or superior to MRI in demonstrating clinically and serologically silent disease activity. Can also demonstrate pulmonary artery involvement. Decrease in FDG uptake on monitoring indicates successful treatment.
Report Sentence
Diffuse increased FDG uptake above liver level in the aorta and branches on PET-CT, consistent with active large vessel vasculitis (Takayasu arteritis).
Concentric wall thickening of carotid and subclavian arteries on ultrasonography (Macaroni sign — long-segment homogeneous hypoechoic wall thickening). Increased peak systolic velocity and post-stenotic turbulence at stenosis sites on Doppler. No flow signal in occlusion. Carotid intima-media thickness (IMT) increase may be an early finding. B-mode US may demonstrate wall thickening in superficial arteries (carotid, subclavian, axillary) before CT/MR. Progression or regression of stenosis degree can be evaluated on follow-up examinations.
Report Sentence
Concentric homogeneous wall thickening (Macaroni sign) of bilateral carotid/subclavian arteries and increased flow velocities at stenosis sites on ultrasonography, consistent with Takayasu arteritis.
Wall thickening, stenosis, or occlusion of the main pulmonary artery and/or branches on CT angiography — an important finding seen in 50% of Takayasu patients. Pulmonary artery wall thickening is concentric and homogeneous. Stenosis is usually seen in lobar or segmental branches. Mosaic perfusion pattern (decreased perfusion in some lobes/segments) may coexist. Pulmonary arterial hypertension may develop. Pulmonary artery involvement is important in distinguishing Takayasu from other large vessel vasculitides (pulmonary involvement is rare in GCA).
Report Sentence
Concentric wall thickening and segmental stenosis of pulmonary artery branches on CT angiography, consistent with pulmonary involvement of Takayasu arteritis.
Aortic aneurysm in the setting of Takayasu arteritis — develops in 15-25% of patients. Aneurysm is typically located in ascending aorta, aortic arch, or descending thoracic aorta. Fusiform morphology is more common (70-80%), saccular morphology may also be seen. Aneurysm formation with wall thickening creates the characteristic 'mixed' (stenotic + aneurysmal) pattern of Takayasu. Dissection may develop as a complication — especially during active inflammation. Aneurysm rupture is rare but life-threatening.
Report Sentence
Fusiform aneurysm of the thoracic aorta in the setting of Takayasu arteritis, forming a mixed (stenotic-aneurysmal) pattern with concentric wall thickening.
Criteria
Isolated involvement of branches arising from the aortic arch (subclavian, carotid, innominate). Aortic arch and descending aorta spared. Most common type seen in Japan.
Distinct Features
Upper extremity pulselessness and cerebral ischemia symptoms dominant. Pulse asymmetry and bruit findings prominent. Relatively good prognosis — renal and coronary involvement rare.
Criteria
Involvement of all aortic segments and branches. Both aortic arch branches, descending aorta, abdominal aorta, and pulmonary artery are affected. Most severe form.
Distinct Features
Highest morbidity and mortality. Renovascular hypertension, pulmonary hypertension, and cardiac complications common. Stenosis/occlusion in multiple vascular territories. Requires aggressive immunosuppressive therapy.
Criteria
Systemic symptoms (fever, malaise, arthralgia, weight loss), elevated ESR/CRP, T2 edema and enhancement in arterial wall on MRI, increased FDG uptake on PET-CT.
Distinct Features
Responds to immunosuppressive therapy. MRI/PET used for treatment monitoring. ESR/CRP elevation indicates disease activity but is not reliable alone (may be normal in 30-40% of silently active disease).
Distinguishing Feature
GCA occurs in individuals >50 years while Takayasu starts at <40 years. Both are large vessel vasculitides showing similar wall thickening on CT/MR. Pulmonary artery involvement is frequent in Takayasu (50%) but rare in GCA. Coronary artery involvement (10-30%) is more frequent in Takayasu. Temporal artery involvement (halo sign) is typical in GCA, absent in Takayasu. Geographic distribution differs: Takayasu common in Asia, GCA in Northern Europe.
Distinguishing Feature
Atherosclerotic aortic disease shows eccentric intimal plaque and calcification; Takayasu shows concentric homogeneous wall thickening. Atherosclerosis prefers infrarenal aorta; Takayasu prefers thoracic aorta and branches. Ostial stenoses of branch vessels are shorter segment in atherosclerosis; long-segment stenoses are typical in Takayasu. Atherosclerosis in elderly, hyperlipidemic patients; Takayasu in young women.
Distinguishing Feature
FMD affects mid-to-distal segments of medium-sized arteries with string of beads pattern; Takayasu affects proximal segments of large arteries with concentric wall thickening. FMD has no inflammation findings; Takayasu has elevated ESR/CRP and wall edema. FMD has no aortic involvement; the aorta is the primary target in Takayasu.
Distinguishing Feature
IgG4-related aortopathy is characterized by periaortic soft tissue thickening ('mantle sign'); Takayasu shows concentric mural thickening but periaortic soft tissue is not typical. IgG4 has elevated serum IgG4 and multiple organ involvement (pancreas, salivary gland, retroperitoneum). IgG4-related aortopathy usually involves infrarenal aorta; Takayasu prefers thoracic aorta and branches.
Urgency
urgentManagement
medicalBiopsy
Not NeededFollow-up
3-monthTreatment of Takayasu arteritis involves suppression of active inflammation and management of vascular complications. Primary treatment is high-dose corticosteroid (prednisolone 1 mg/kg/day, tapering after 4-6 weeks). Methotrexate, azathioprine, or mycophenolate mofetil is added in steroid-resistant or dependent cases. Biologic agents (tocilizumab — IL-6 blocker) are promising in refractory cases. Vascular revascularization (percutaneous angioplasty/stent or surgical bypass) may be needed in patients with hemodynamically significant stenosis — but should be performed after active inflammation is controlled (high restenosis rate in active phase). Renovascular hypertension treatment (ACE inhibitor or ARB) is important. MRI (T2 edema, mural enhancement) and PET-CT are more reliable than ESR/CRP for disease activity monitoring. Regular clinical and imaging follow-up is required lifelong.
Treatment of Takayasu arteritis is immunosuppressive (corticosteroids + steroid-sparing agents) and revascularization when needed (endovascular/surgical — during remission). Disease activity is monitored with MR and PET. Renal artery stenosis can lead to renovascular hypertension, coronary involvement to myocardial ischemia. Pregnancy management requires special attention.