The utility of color duplex ultrasonography in the diagnosis of temporal arteritis

Purpose: Temporal arteritis (TA) is frequently diagnosed with nonspecific clinical characteristics, followed by a temporal artery biopsy to confirm the presence of vasculitis. Consequently, numerous screening surgical biopsies are performed with a high negative-biopsy rate. A prospective study was performed evaluating color duplex ultrasound scan (CDU) as the preferred method for the diagnosis of vasculitis in the evaluation of suspected TA. Methods: Thirty-two patients with suspected TA on the basis of clinical criteria were evaluated with CDU before a temporal artery biopsy. The presence of a hypoechoic "halo," suggesting edema of the inflamed vessel, and inflammatory sterroses were noted. Histologic examinations of standard temporal artery biopsies then were performed, and the results were compared with the CDU findings. In addition, a metaanalysis was performed to identify articles related to the use of ultrasound scan in the detection of TA. Results. All patients completed a bilateral CDU examination of the temporal arteries, and in 75% of patients biopsied, no evidence of vasculitis was found at histologic examination. When CDU examined for halo alone as the determinant for disease, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), compared with histologic confirmation of TA, were 85.7%, 92.0%, 75.0%, and 95.8%, respectively. With the criteria for a halo sign present, an inflammatory stenosis present, or both present on CDU, the sensitivity, specificity, positive predictive value, and NPV were 100%, 80.0%, 58.3%, and 100%, respectively. Conclusion: CDU is a superior noninvasive method of determining the presence of vasculitis when compared with routine surgical biopsy. Examination of the temporal artery with CDU can effectively predict which patient will need surgical biopsy. The utility of CDU in the diagnosis of TA is maintained by a high sensitivity in detecting patients with the disease and also by a high NPV that can eliminate patients who would not benefit from biopsy.