The “Macaroni Sign”
A 24-year-old woman presented with sudden paresis of the right hemisoma. Systolic blood pressure in the left arm was 80 mm Hg and in the right arm was 110 mm Hg. The laboratory data showed systemic inflammation (erythrocyte sedimentation rate: 47 mm/h; C-reactive protein, 3.57 mg/dL). Echo-color Doppler showed homogeneous, midechoic, circumferential wall thickening of the left common carotid artery (Figure). This rare ultrasonographic finding, previously described by Maeda et al1 as the “macaroni sign,” is pathognomonic for Takayasu’s arteritis, an inflammatory granulomatous disease of medium- and large-sized arteries (epiaortic especially) that is prevalent in young women. Mononuclear and giant cells infiltrate walls, typically the media and adventitia; proliferation of intima and degeneration of the external elastic lamina occur, with formation of stenosis, occlusions, and aneurysms. Echo-color Doppler enables a differential diagnosis with the large-vessel giant cell arteritis: It is more acute than Takayasu’s arteritis, and there is more mural edema, resulting in a darker (hypoechoic) wall thickening. Ultrasonography and angiography are complementary methods for the diagnosis of Takayasu’s arteritis. Angiography may show significant luminal changes in many vessels, whereas ultrasonography may show both characteristic and minimal wall changes, although in a smaller number of arteries.