Purpose: In patients with suspected giant cell arteritis (GCA), a search for the perivascular halo sign, a sophisticated color duplex ultrasound (CDU) finding, at experienced centers reliably identifies inflamed temporal arteries (TA). We tested whether TA compression in patients with GCA, a simple, largely operator-independent maneuver, elicits contrasting echogenicity between the diseased artery wall and the surrounding tissue (compression sign). Materials and Methods: 80 individuals with suspected GCA were prospectively enrolled in this single-center study. In all study participants, bilateral ultrasound examination of the TA established the presence/absence of the halo and compression sign. A positive compression sign was defined as visibility of the TA upon transducer-imposed compression of the artery. Based on ACR criteria, a team of specialized physicians independently grouped patients as GCA versus non-GCA. Results: 43/80 study participants were grouped as GCA. Both the halo sign and the compression sign were positive in 34/43 patients in the GCA group, and negative in all 37/37 of the non-GCA group, resulting in a sensitivity of 79?% and a specificity of 100?% for both the halo and the compression sign. Conclusion: In this cohort of individuals with suspected GCA, the halo sign and the compression sign were equal in their diagnostic performance. The simplicity of the compression sign suggests a level of reliability warranting further evaluation.

The use of contrast-enhanced ultrasound (CEUS) for vascular imaging indications has increased dramatically during the last decade. Ultrasound contrast agents are gas-filled microbubbles that are injected into the bloodstream and serve as strict intravascular reflectors of ultrasound waves. Numerous studies have addressed the potential clinical use of CEUS in different vascular fields including the carotid arteries, the abdominal aorta, renal arteries and the kidneys. In this review article we discuss the clinical value of contrast agents in vascular ultrasound by enhancing the vascular lumen, and more important, their role as a tool to deliver high resolution, real-time images of microvascular perfusion. Specifically, CEUS imaging of the carotid artery provides a novel, non-invasive method not only to improve the delineation of the vessel wall, but also for the assessment of the vasa vasorum and the ectopic vascularization of the atherosclerotic plaque (intraplaque neovascularization); probably providing a "window" to risk stratify atherosclerotic lesions and individuals by identifying "vulnerable" plaques prone to rupture causing vascular events. CEUS imaging has also emerged as a novel diagnostic tool in various aortic pathologies and particularly for the detection of endoleaks following endovascular treatment of abdominal aortic aneurysms. It is also a valuable tool for the assessment of the tissue perfusion in native and transplanted kidneys providing information on perfusion deficits of the parenchyma. Furthermore, a real-time CEUS method has recently been developed to assess the skeletal muscle microcirculation which could be used to study patients with peripheral arterial occlusive disease or diabetic microangiopathy. In the future, the use of targeted microbubbles could further enhance and expand the diagnostic capabilities of current vascular ultrasound imaging by detecting specific molecular processes that play a role in the pathophysiology of vascular disease.

Controlled-compression sonography is a valuable tool for measuring venous pressure in peripheral veins and allows reliable indirect assessment of CVP without intravenous catheterization.

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Objectives [18F]Fluorodeoxyglucose (FDG)-PET/CT and US are both well established for diagnosing GCA. The present study investigates their accuracy and whether they provide overlapping or complementary information in a cohort of patients presenting with suspicion of GCA. Methods We selected consecutive patients from our cohort of suspected GCA cases that underwent both extended vascular US and PET/CT for diagnostic work-up between December 2006 and August 2012. Results A total of 102 patients were included. Diagnosis of GCA was confirmed in 68 patients and excluded in 34 patients (controls). Vasculitic changes in US were most often found in the temporal artery with 32 positive findings on each side, followed by the popliteal artery (10 right, 9 left) and the subclavian/axillary artery (7 right, 8 left). By contrast, PET/CT showed vasculitis most frequently in the vertebral (23 right, 33 left) and common carotid arteries (32 right, 24 left), followed by the subclavian arteries (16 right, 18 left), and the thoracic (17) and abdominal aorta (23). In 37/68 GCA patients PET/CT and US both revealed vasculitic findings, 11/68 had positive findings in US only and 14/68 in PET/CT only. Specificity of US was higher (one false-positive vs five false-positive in PET/CT). On a single segment level, only 20 of 136 positive segments were positive in both imaging modalities. Conclusion PET/CT measuring vessel wall metabolism and US vessel wall morphology showed a comparable diagnostic accuracy for GCA. However PET/CT and US were often discrepant within single vascular regions. Thus PET/CT and US should be considered as complementary methods, with a second imaging modality increasing the diagnostic yield by 16–20%.