Magnetic Resonance Angiography and Multidetector CT Angiography in the Diagnosis of Takayasu's Arteritis: Assessment of Disease Extent and Correlation with Disease Activity

Background: Takayasu’s Arteritis (TA) is a large vessel vasculitis with diverse clinical presentations and arterial vascular bed involvement.It is characterized by chronic, nonspecific inflammation of all layers of the vessel wall which results in stenosis, occlusion, dilatation, or aneurysm formation in the involved blood vessels. Methods: The study included 36 patients of TA. All patients fulfilled the modified Ishikawa’s diagnostic criteria for TA. All patients were evaluated for clinical presentation, angiographic findings, and severity of the disease. The disease activity was assessed based on Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP) and also by CT Angiography (CTA)/Magnetic resonance angiography (MRA) imaging. The angiographic types were classified based on the International TA Conference in Tokyo 1994 angiographic classification. Results: A total of 36 patients were included in the study, 86% were females and a mean age of 21.6 years. Hypertension (78%) was the most common clinical presentation. Type V was the most common angiographic type (42%) followed by type III (25%), type IV (14%), type IIb (11%), type I (5%) and type IIa (3%). Among the aortic arch branches the left subclavian artery (50%), right subclavian artery (38.8%), left vertebral artery (33.3%) and left common carotid artery (27.7%) were the most commonly involved arteries. Disease activity based on CT / MR imaging showed a significant statistical correlation with elevated ESR and positive CRP (p < 0.0001). Mediastinal lymphadenopathy was seen in 21 patients out of which 11 had active disease. However, no significant correlation was found between mediastinal lymphadenopathy and disease activity. Conclusion: TA presents with varied symptomatology and differing vascular involvement. CT/MR angiography is effective in diagnosis and accurately predicted the active stage of the disease.