Objective: To evaluate the usefulness of MRI as a diagnostic tool for detection of TA and to elucidate the role of contrast-enhanced MRI (CE-MRI) in assessing the disease activity of TA.

Materials and Methods: Fourteen patients (aged 20 to 60 years; mean 33.9 years) diagnosed as TA were included in this study. Duration of symptoms ranged from 2 months to 30 years. MR imaging was performed 18 times including follow-up scanning up to 20 months after initial MRI in four patients. For determination of the degree of aortic wall enhancement, T1-weighted axial and oblique sagittal images were obtained immediately, 5-10 mine later, and 11-20 minutes later after contrast media injection. The degree of aortic wall and myocardial enhancement was measured by using small ROIs (1-7 mm2). The aorta and its branches were evaluate with digital subtraction angiography (DSA) in three patients

Results: T1-weighted imaging revealed variable degree (4-7 mm) of aortic wall thickening in all patients. Aortic aneurysm was found in four patients and dilatation was found in three patients. In aortic branch vessels, MRI clearly showed stenosis and occlusion. Determination of disease activity by CE-MRI was concordant with clinical findings in all 18 scan times. The aortic mural signal intensity compared with that of myocardium at CE-MRI correlated well with ESR (r = 0.61, p < 0.01). However, in three patients who were still clinically active but had normal ESR after treatment, MRI showed findings of active disease. Finding of MR angiography correlated well with intraarterial DSA for 12 aortic segments and 30 arteries (93%) in three patients.

Conclusion: Contrast-enhanced MRI provides information on disease activity and extent of TA at its various stages, which can be used in diagnosis as well as assessing the treatment response in TA.

Purpose: To evaluate the capacity of B-Mode ultrasonography (B-Mode US) and electron-beam computed tomography (EBCT) to detect arterial changes in Takayasu arteritis (TA).

Patients and Methods: EBCT angiography of the thoraco-abdominal aorta and pulmonary artery, B-Mode US of large superficial arteries (common carotid, subclavian and common femoral arteries) and abdominal aorta were performed prospectively in 43 consecutive patients with TA. The arterial wall thickness was measured and lumen changes (stenosis, aneurysm) were noted.

Results: The combined results of B-Mode US and EBCT examinations showed that all patients had at least one abnormality at the studied sites. The median score of abnormal sites was 7. The most frequent lesion was a characteristic long, homogenous, circumferential thickening, visualized in 50% of examined sites and present in all patients but one (98%). Stenosis was detected by US and EBCT in 44% and 8% of patients, and aneurysm in 0.7% and 11%, respectively.

Conclusion: In TA, B-Mode US and EBCT proved to be able not only to visualize the classical caliber abnormalities (stenosis, aneurysm) but also to depict, in contrast to angiography, the vessel wall thickening, a major pathological feature of the disease. Both these safe techniques seem more useful than angiography to characterize and to map the vascular lesions of TA. Conventional angiography, however, should still be performed in the preoperative phase of bypass surgery and percutaneous transluminal angioplasty.

Purpose: To evaluate pulmonary artery changes in Takayasu arteritis by electron-beam computed tomography (EBCT).

Patients and Methods: EBCT angiography was performed prospectively in 41 consecutive patients with TA (group I), to assess pulmonary artery involvement (PAI). Forty patients who underwent EBCT for suspected pulmonary embolism were used as controls (group II). After an initial precontrast scan, pulmonary artery was imaged by a breath-hold spiral scan. Criteria for PAI were: wall thickening, pulmonary dilatation or stenosis, spontaneous high-attenuation, and low attenuation areas in pulmonary parenchyma.

Results: In group I, 6 patients (15%) had diffuse wall thickening, 14 (34%) had lumen abnormalities (12 dilatations and 2 stenosis), 4 (10%) had spontaneous high-attenuation wall, and 10 (24%) had low attenuation areas in pulmonary parenchyma, versus 0, 0, 1 (3%) and 4 (10%) respectively in group II. The difference between the two groups was significant for the first 2 criteria (p < 0.05), but not for the last 2. At final assessment, 13 patients (32%) had PAI.

Conclusion: Diffuse wall thickening and dilatation or stenosis are the most specific EBCT criteria for PAI in TA.