A 29-year-old woman with known Takayasu arteritis (TA) involving the aortic arch and its branches, and treated with corticosteroids and infliximab, was referred to magnetic resonance imaging (MRI) because of worsening dyspnea. ECG-gated 1.5 T cine (steady-state free precession) images and black-blood T1-weighted fast spin-echo images showed intermediate signal wall thickening of the ascending aorta, the aortic arch and the main pulmonary artery. In addition, the lumen of the right pulmonary artery appeared to be severely reduced due to important wall thickening (Fig. 1a–d). Black-blood T2weighted fast spin-echo images with fat suppression using inversion-recovery technique revealed marked enhancement of the walls of the ascending aorta, and main and right pulmonary artery (Fig. 2a, b). In addition, these areas showed late enhancement on contrast-enhanced inversion-recovery T1-weighted fast gradient-echo images obtained 10 min after injection of gadolinium chelate contrast agent (Fig. 3). Both these findings indicated active inflammation. Three-dimensional MR angiography performed after administration of gadolinium chelate contrast agent confirmed the subocclusion of the right pulmonary artery (Fig. 4a, b). These MRI findings were consistent with active TA involving the aorta and the pulmonary arteries; in particular, the symptoms of our patient were largely attributable to pulmonary arterial manifestations of TA, which led to severe stenosis of the right pulmonary artery. TA is a rare, progressive, inflammatory and obliterative disease of large vessels [1]. Most commonly, it involves the aorta and its major branches. Pulmonary artery involvement is less frequently observed and is considered a late manifestation of the disease [1]. Segmental and subsegmental branches are the sites in the pulmonary arterial system most often affected; conversely, stenosis or occlusion of lobar or main pulmonary arteries is more rarely observed [1]. Pathologic features of pulmonary artery involvement includes intimal fibrosis, thinning of the media with disruption of elastic fibers, band-like fibrosis of the adventitia, and complete occlusion of the pulmonary artery due to loose fibrous tissue in the lumen [2]. Conventional angiography has been traditionally used in the past in the clinical workup of patients with TA. Recently, computed tomography and MRI have been shown as useful noninvasive imaging modalities, as in other cardiovascular diseases [3–22]. In particular, MRI is an effective tool for early diagnosis, severity assessment and follow-up of TA. Besides determining the presence of luminal narrowing, MRI can indeed provide additional anatomic information, including vessel wall thickness, and can determine disease activity, disclosing mural inflammatory signs [3, 23]. G. Nucifora (&) G. Todiere D. De Marchi A. Barison G. D. Aquaro M. Lombardi Fondazione CNR/Regione Toscana Gabriele Monasterio, Via Moruzzi 1, 56124 Pisa, Italy e-mail: gnucifora@cardionet.it