Images in Vascular Medicine: Usefulness of carotid ultrasonography for diagnosis and management of polymyalgia rheumatica-associated large-vessel vasculitis

Abstract

A 75-year-old man presented with acute-onset bilateral shoulder and hip pain accompanied by fever and leftsided neck tenderness. A positron emission tomographycomputed tomography (PET-CT) scan showed fluorodeoxyglucose accumulation in both shoulders and hip joints and in the intervertebral discs in the lumbar region (Panel A-1), suggesting polymyalgia rheumatica (PMR).1 In addition, the scan revealed massive fluorodeoxyglucose accumulation in the left common carotid artery (Panels A-2 and A-3: arrow). Contrast-enhanced CT and magnetic resonance imaging (MRI) also showed thickening of the arterial wall of the left common carotid artery (Panels B-1 and C-1: arrow). Mural contrast enhancement with MRI on T1 sequences suggested active inflammation (Panel C-1: arrow). Carotid ultrasonography was conducted for suspected arteritis; it revealed remarkable thickening of the outer layer of the left common carotid artery. Heterogeneous echogenicity of the outer layer of the left common carotid arterial wall also suggested edema caused by inflammation (Panels D-1 and D-3: arrows). The patient was treated with prednisolone (initial dose 60 mg daily) and subcutaneous tocilizumab (162 mg weekly). Four weeks after treatment initiation, CT and MRI showed an improvement in the arterial wall thickness (Panels B-2 and C-2: arrow). Interestingly, the serial ultrasound images also showed an improvement in the thickened wall of the left common carotid artery, with no alteration of the luminal diameter (Panels D-2 and D-4: arrows). PMR is often associated with giant cell arteritis (GCA), which exhibits thickening of the intimal layer and disruption of the media.2 Although our case had thickening of the outer layer, there was no other indication that suggested this entity was different from GCA. Therefore, our case was categorized as PMR-associated large-vessel vasculitis (LVV). PET-CT, CT, and MRI have been widely used for the diagnosis and management of LVV. Although they enable whole-body imaging, it is not practical to use them to assess vascular morphology or subclinical large-vessel involvement in all patients presenting with PMR. The use of ultrasonography could help identify patients with subclinical LVV, who may benefit from additional crosssectional imaging to screen for aortitis. In one study, 4% of patients with PMR had temporal artery biopsy lesions consistent with GCA in the absence of clinical symptoms, and one-third demonstrated subclinical LVV on PET-CT imaging.3 In addition, this case suggests the use of ultrasonography as a supportive, nonradioactive imaging tool, not only for diagnosing but also for managing subclinical LVV in patients with PMR. Images in Vascular Medicine: Usefulness of carotid ultrasonography for diagnosis and management of polymyalgia rheumatica-associated large-vessel vasculitis