In this issue, Rizwan et al. report a study evaluating the utility of cranial CT angiography (CTA) for the diagnosis of giant cell arteritis (GCA) by examining the association between CTA findings and superficial temporal artery biopsy (TAB) results. ^{Reference Rizwan, Khatri and Basseri1} The authors found that a blurred superficial temporal artery (STA) wall and perivascular enhancement on CTA were associated with increased odds of a positive TAB. This study adds to the growing body of literature supporting diagnostic imaging for the evaluation of GCA. The 2023 European Alliance of Associations for Rheumatology (EULAR) recommendations endorse ultrasound as the first-line imaging modality to evaluate patients with suspected GCA. ^{Reference Dejaco, Ramiro and Bond2} However, in some areas, including much of the USA, the use of ultrasound is limited by the availability of high-level technical expertise. ^{Reference Maz, Chung and Abril3} Other imaging modalities, including [18F]fluorodeoxyglucose PET-CT and MR angiography, have shown good diagnostic performance but are costly and time-consuming. CTA, which is quick and widely available, could be a game changer for the diagnosis of GCA.

The 2023 EULAR recommendations removed prior discouragement of the use of CTA for assessing inflammation in superficial cranial arteries, acknowledging that these vessels can be visualized with CTA. ^{Reference Dejaco, Ramiro and Bond2} Nevertheless, due to limited prospective data, CTA was not specifically recommended in this updated guidance. The current study provides an important data point supporting further evaluation of cranial CTA in GCA diagnosis. There have been limited studies assessing cranial CTA for GCA. A prior study reported CTA detection of STA abnormalities with a sensitivity of 54% and specificity of 81%. ^{Reference Conway, Smyth and Kavanagh4} The current work adds useful data supporting CTA’s potential role in early GCA diagnosis, though it is limited by its small size and single-center design. Additionally, this study used TAB results, which have limited sensitivity, ^{Reference Rubenstein, Maldini and Gonzalez-Chiappe5} to define GCA disease state. If some biopsy-negative patients actually had GCA, the negative predictive value and the estimated odds ratios in the current study would be lower.

While the potential role of CTA in GCA diagnosis is exciting, more study is needed. In addition to larger studies evaluating the sensitivity, specificity and predictive values of CTA findings, questions remain regarding the optimal timeframe for CTA evaluation with respect to initiation of steroid therapy, the inter-observer agreement of neuroradiologists and community radiologists with regard to pertinent CTA findings and whether inclusion of additional vessels (beyond the STA) may increase the sensitivity of CTA. We look forward to further work in this area.