Giant-cell arteritis on photon-counting detector CT: A case report.

A 77-year-old woman presented to our hospital with a 2-week history of fever, headache, and induration along the bilateral superficial temporal arteries (STAs). The color Doppler ultrasonography of the STA showed a hypoechoic mural thickening surrounding a residual color flow. A contrast-enhanced photon-counting detector (PCD) CT demonstrated mural thickening and stenosis of the bilateral STAs. The patient underwent a biopsy of the right STA. Histopathological findings were consistent with giant cell arteritis (GCA). The patient's symptoms were temporarily relieved after initiation of steroid treatment, but jaw claudication occurred 2 months later. Contrast-enhanced CT showed improved vascular abnormalities of the STAs but new mural thickening and stenosis of the bilateral maxillary artery. Due to its higher resolution, image contrast, and lower noise, PCD-CT may have great potential in detecting, diagnosing, and monitoring GCA.