The role of ultrasound biomicroscopy in the diagnosis of temporal arteritis.

Temporal artery biopsy is considered the gold standard for the diagnosis of temporal arteritis (TA). The aim of the study was to determine whether ultrasound biomicroscopy (UBM) findings are useful in predicting the result (positive or negative) of temporal artery biopsy in patients with TA. Sixteen consecutive patients (ten women and six men) with clinical diagnosis of TA seen at the Ophthalmology Unit, S. Marta Hospital, Catania University, were included in the study. All patients were submitted to UBM (50-MHz transducer, P45 Plus Paradigm Medical Instruments, Salt Lake City, UT, USA) before temporal artery biopsy. The results were correlated with histopathologic changes. Seven patients presented histopathologic findings consistent with the diagnosis of TA. Thus, UBM findings of these patients were compared with those of the nine patients with negative biopsy. On UBM, we searched for the presence of a hypoechoic effect surrounding the walls of temporal arteries, so-called halo sign, as well as for the intra-arterial middle reflexive filling, so-called intra-arterial filling. The halo sign and intra-arterial filling were found in all seven (100%) patients with biopsy-proven TA. However, in five (55.5%) patients, the absence of these two parameters on UBM of patients with suspected TA strongly suggested that temporal artery biopsy would be negative (negative predictive value, 100%). On the other hand, four (44.5%) of nine patients with negative biopsy presented one of these two UBM findings. In conclusion, this preliminary work suggested UBM to be an appropriate noninvasive tool for morphological imaging and evaluation of temporal arteries, helpful in obtaining an indication of the side and segment for biopsy, and may play a role in predicting negative result of temporal artery biopsy in patients with TA; however, for the time being we cannot recommend any change in the current practice.