Background/Purpose:

Color Doppler ultrasound (CDUS) and
Magnetic resonance angiography (MRA) has been extensively used in the
diagnostics of large vessel vasculitis (LVV) [giant cell arteritis (GCA) and
Takayasu arteritis (TA)]. No studies exist, which compare the diagnostic
accuracy of CDUS and MRA of LVV in the supra-aortic large vessels. The aim of
this study is to perform a head-to-head comparison between CDUS and MRA of
temporal arteries and supra-aortic large vessels in a group of LVV patients.

Methods:

MUSES (Magnetic resonance
angiography vs Ultrasonography in Systemic large vEssel vasculitis, Clinical
Trials.gov NCT02042092), is a prospective cross-sectional study. Patients
diagnosed with LVV by ultrasound, MRA, Computed Tomography Angiography or
Positron Emission Tomography, were identified and included in MUSES at the
Department of Rheumatology, in Kristiansand between January 2014 and January
2015. One ultrasonographer experienced in the use of vascular ultrasound (APD)
examined and recruited the LVV patients. MRA imaging was performed within one
week after the ultrasound evaluation and one radiologist evaluated the MRA
images locally (FL). The common temporal, carotid, subclavian, vertebral,
axillary arteries and the thoracic aorta were evaluated. Films and images of CDUS
and MRA examinations were recorded.  The recorded data has been surveyed by two
external experts, one on vascular ultrasound (WAS) and one on MR imaging (JG).
Both experts were blinded to clinical and laboratory data and were unaware of distribution
and size of the vasculitis lesions. The experts applied a dichotomous score
(vasculitis: yes/no) in every evaluated vessel. The identification of vasculitis
in any vessel represented an independent result.

Results:

Twenty-seven patients were
recruited [(12 males, 15 females, median
age 69 years (IQR 62-76)]. Twenty-five patients were diagnosed with GCA and 2
with TA. Eight patients had new onset LVV and 19 had long lasting disease (median
disease duration 2 years, IQR 0-5). Median time between CDUS and MRA
examination was 2 days (IRQ 1-4). Median CRP was 8 mg/l (IQR 3-24) and ESR 24 mm/hr.
(IQR 9-53). In two patients, no vasculitis changes were observed in any vessel,
either on CDUS or MRA. In the remaining 25 patients, CDUS revealed vasculitis
in all patients, while MRA was positive in 20 patients. The temporal artery and
the supra-aortic vessels in which CDUS, MRA or both modalities revealed
vasculitis changes are presented in table 1.

Conclusion:

It seems that CDUS is more sensitive to detect
vasculitis changes in large vessels. Further, CDUS revealed vasculitis in more
patients than MRA. Thus, we recommend CDUS as a first line evaluation in all
patients suspected to have LVV.  

Table 1.