Purpose or Case Report: Takayasu's arteritis (TA) is one of the most common childhood vasculitides, primarily involving large and, to a lesser extent, medium sized arteries. The aorta and pulmonary arteries are most frequently affected. Historically, diagnosis depended on typical fluoroscopic angiographic features, in conjunction with a number of clinical and hematologic criteria. Increasingly, a range of imaging modalities is used in initial diagnosis as well as for monitoring disease progression and treatment response. The purpose of this educational exhibit is to provide an update on the current role of imaging in TA, defining disease extent and activity, as well as highlighting end organ complications.
Methods & Materials: Utility and limitations of ultrasound (US), computed tomographic angiography (CTA), magnetic resonance angiography (MRA), and digital subtraction angiography (DSA) are discussed. Technical considerations for image optimization in children and adolescents are considered, based on literature review and the authors’ experience in pediatric cardiovascular and body imaging. The imaging characteristics of TA across these modalities are illustrated through several cases.
Results: Primary manifestations of TA depend on disease chronicity. Mural and perivascular thickening and enhancement are signs of acute disease and can be seen on CTA with its high spatial resolution. Arterial narrowing and occlusion, observed both acutely and with chronic TA are well demonstrated by DSA, CTA and MRA. MRA’s superior contrast resolution further aids distinction of active from inactive disease, avoiding ionizing radiation, as does US. MRA and US can also demonstrate altered flow dynamics. US depicts lumen, mural and perimural changes, although with small field of view; US contrast agents are increasingly used for wall enhancement.(Figure 1) End organ complications can involve the heart, lungs, bowel or solid abdominal organs. Imaging choice and related findings depend upon the clinical presentation, such as US or MRA for suspected bowel ischemia with wall thickening and mucosal enhancement.(Figure 2)
Conclusions: The range of modalities now utilized in TA evaluation has expanded. Comprehensive knowledge of the role of each helps ensure the most suitable technique is applied to resolve the clinical question during disease evolution, while minimizing risk. Distinguishing active from inactive disease and recognizing complications guide care for patients with TA.