Background/Purpose:

Temporal Arteritis (TA) is the most common large vessel vasculitis, affecting adults over the age of 50. It is associated with significant morbidity due to ischemic manifestations such as blindness and stroke.¹ The gold standard for diagnosis has always been temporal artery biopsy (TAB) and although highly specific (98%) it lacks sensitivity, and can yield false-negative results in up to 60% of cases. The emergence of CDS in the diagnosis of GCA has now been widely acknowledged, further supported by meta-analyses confirming its validity.² Prospective postulate a better sensitivity compared to TAB.³ For hospitals with no prior experience in TA-CDS a common validity concern lies in the procedures intra-operator reliability.

Methods:

A temporal arteritis (TA) pathway incorporating CDS was introduced into a small UK district general hospital serving a population of 200,000. It was presented at a local hospital medical meeting attended by all doctors to raise awareness. Subsequently the pro forma was distributed throughout the trust including medical wards, Accident and Emergency (A&E) and the Medical assessment unit (MAU). 

As part of the pathway every patient who was referred for a TAB (performed by the Maxillofacial surgeons), also underwent a CDS. The latter was performed by one musculoskeletal (MSK) Consultant Radiologist who was blinded in terms of patient symptoms i.e. side of headache. Crucially the radiologist although experienced (n= 20,000 MSK Ultrasound studies) has not been trained specifically in temporal artery ultrasound. Patients would then be followed up in Rheumatology Outpatients with the results of the investigations within 4 weeks.

TAB had a specificity of 100% in contrast the sensitivity was 23% (Sensitivity 84% for CDS).

Conclusion:

TA can be a challenging diagnosis for clinicians to make; hence diagnostic investigations are important. Our results demonstrate the critical role and value of CDS in the diagnosis and management of TA. When clinical suspicion is high for TA our data shows CDS as specific as TAB, but more importantly even when a radiologist is new to the procedure significantly higher sensitivity when compared to TAB (84%, P<0.023). Despite non familiarity of the operator the procedure adds to the diagnostic process. Our study data is line with existing data, ^2,3 and highlights the necessity to incorporate CDS in the diagnosis of TA.

References

1.Jennette JC, Falk RJ, Bacon PA et al. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Arthritis Rheum 2013;65:1-11

2. Karassa FB, Matsagas MI, Schmidt WA et al. Meta-ana– lysis: test performance of ultrasonography for giant-cell arteritis. Ann Intern Med 2005;142:359-69.

3. Luqmani R, Lee E, Singh S, Gillett M et al (2016). The role of Ultrasound Compared to biopsy of Temporal Arteries in the Diagnosis and Treatment of Giant Cell Arteritis