TAKAYASU ARTERITIS IN THAILAND - CLINICAL AND IMAGING FEATURES

Purpose: To present and evaluate the clinical and imaging features of patients with Takyasu arteritis in Thailand. Materials and methods: Cl inical and angiographic findings were studied in 63 patients with Taka yasu arteritis collected at Chulalongkorn Hospital Medical School, Ban gkok. Imaging features including CT scan in 15 patients, magnetic reso nance imaging in 14 patients and magnetic resonance angiography in ten patients were evaluated and compared to angiography. Results: Among 6 3 patients there were 43 females and 20 males with the ratio female to male 2.15:1. The most common age groups were in the third and fourth decades of life. The most common clinical findings were hypertension a nd absence or weakness of pulses. Elevated erythrocyte sedimentation r ate was found in 50%. For angiography, the most common vessel affected was the abdominal aorta (20%). The second and third most common sites were renal arteries (18.7%) and the subclavian arteries (14.3%). Coro nary artery involvement was found in two out of eight patients. No pul monary involvement was found in eight cases studied by pulmonary angio graphy. For classification of angiogram, the most common type of invol vement (66.7%) was extensive involvement of the aorta and branches (ty pe V of new classification established from International Conferences on Takayasu arteritis in Tokyo 1994). No patient was found to have onl y involvement of brachiocephalic branches or ascending aorta and brach iocephalic branches. CT scan showed calcification in the vessel walls (8/15 cases) which helped in diagnosis of the disease. Wall thickness, surrounding tissue, appearance of the vessel and intraluminal thrombu s could be well seen. Magnetic resonance imaging added more detail in multiple planes and could demonstrate vascular flow. High detection ra te of the lesions (94.8%) was found for the aorta. The study was less sensitive for smaller vessels. Magnetic resonance angiography showed b etter correlation of the findings of brachiocephalic arteries compared to angiography. Subclavian steal syndrome could be diagnosed. For ren al arteries, MR angiography could correctly demonstrate occlusion of r enal artery in six out of eight cases. In the other two cases only ste noses of the vessels were found on angiograms. One renal arterial sten osis on MR angiography was confirmed by angiography. Conclusion: Takay asu arteritis could be found in Thailand. Clinical features were almos t the same as in reports from other countries. Various forms of arteri al involvement were demonstrated by imaging modalities. Angiography re mained the best method for detection and diagnosis of Takayasu arterit is in correlation with clinical and laboratory findings. Although CT s can, magnetic resonance imaging and magnetic resonance angiography wer e limited and less sensitive for detection of the lesions, they were u seful as noninvasive modalities showing more details of intraluminal c lot, vascular wall and surrounding tissue which could be correlated wi th pathological findings and pathogenesis of the disease. Our study su ggests that MR imaging and MR angiography can be screening and diagnos tic techniques for patients with suspected Takayasu arteritis.