Contrast-enhanced ultrasound of carotid artery wall in Takayasu disease: first evidence of application in diagnosis and monitoring of response to treatment.

A 35-year-old woman with chronic anterior cervicalgia was referred to our institution for an ultrasound of the neck. The B-mode ultrasound (Siemens S 2000, linear phased array probe 9 to 13 MHz) revealed a 1.6-mm hyperechoic circumferential wall thickening of the right common carotid artery, involving the whole artery, without evidence of stenosis (Figure 1). The other supraaortic arteries appeared normal. Positron-emission tomography and computed tomography scans demonstrated further localizations of arterial wall thickening in the right brachiocephalic artery, the aortic arch, and the abdominal aorta. The patient’s long medical history of hypertension, carotidynia, radial pulse asymmetry, and biological inflammatory syndrome along with the imaging results led to the diagnosis of Takayasu disease.1 Contrast-enhanced ultrasound of carotid arteries was then performed (T0) before the patient started steroid treatment. We used a Siemens S 2000, 9to 13-MHz probe, and a 3-second intravenous (IV) bolus of 1.5 mL of Sonovue (Bracco, Altana Pharma, Konstanz, Germany) flushed with 5 mL of saline. A picture was taken 1 minute post-IV and a 30-second movie was recorded 15 seconds post-IV, at the beginning of arterial opacification. Pictures were then postprocessed by Adobe Photoshop CS4 extended software to measure the gray scale median (GSM) of the right common carotid wall. The use of this software to calculate the GSM has been shown to provide a reproducible gray scale numeric evaluation of a selected area,2 ranging from 0 (black) to 255 (white), validated as an objective measure of echogenicity. The same protocol of contrast-enhanced ultrasound was performed 3 months (T1) and 6 months (T2) after the beginning of treatment, by the same operator in identical technical conditions. During that time, under steroid treatment, the patient’s symptoms improved dramatically and the biological inflammatory syndrome resolved. The B-mode ultrasound appearances did not change during the 6 months, showing a stable 1.6-mm hyperechoic circumferential wall thickening of the right common carotid artery. On contrast-enhanced ultrasound, however, the pretreatment scan showed a marked arterial wall enhancement with direct visualization of multiple opacified vasa vasorum (Figure 2 and Movie I in the online-only Data Supplement). These appearances changed progressively at T1 (Movie II in the online-only Data Supplement) and T2 (Movie III in the online-only Data Supplement) with the impression of marked diminution of arterial wall enhancement and vasa vasorum opacification. That was confirmed by the GSM measures, which significantly decreased during the 6 months: GSM at T0, 80.58 (Figure 2); at T1, 42.09 (Figure 3); at T2, 5.05 (Figure 4), illustrating the lowering echogenicity of the pathological arterial wall under treatment. B-mode ultrasound and GSM index are currently used to assess the stability of atherosclerotic plaques.3 With contrastenhanced ultrasound imaging, the GSM increases in atherosclerotic disease with the degree of enhancement of the parietal wall, which itself reflects the neovascularization and Figure 1. Mode-B ultrasound: right common carotid artery circumferential wall thickening suggesting inflammatory arteritis.