Abstract TP203: Factors Associated With Temporal Window Failure in Transcranial Doppler Sonography

Abstract

Background and purpose: Temporal window failure (TWF) is found in 8-20% of subjects. Although it has been reported that, it is more common for the elderly and females, there are not enough studies on this topic. This study aimed to identify new factors affecting TWF. Methods: This study analyzed 376 patients who underwent both transcranial Doppler sonography (TCD) and cerebral angiographic imaging among patients visited the neurology department of Chonbuk National University Hospital from January to December 2018. They were divided into two groups depending on the presence of TWF. Afterward, demographics and cardiovascular factors, degree of stenosis from proximal intracranial artery (ICA) to the middle cerebral artery (MCA), and MCA diameter and skull features were examined. Results: The mean age of the patients was 68.4±12.1 years old and 241 of them (64.1%) were male. The study subjects were composed of 314 TWF negative patients (83.5%) and 62 TWF positive patients (16.5%). The stenosis from the proximal ICA to the 2/3 segment of the MCA proximal was not different between the two groups. Factors affecting TWF were analyzed using multivariate logistic regression analysis and the results showed that age (odds ratio [OR], 1.05; p =0.019), female (OR, 4.64; p =0.002), temporal bone thickness (OR, 6.03; p <0.001), temporal bone density (OR, 0.996; p =0.002), and soft tissue thickness (OR, 1.31; p =0.004) significantly affected TWF. Conclusions: We confirmed that the soft tissue thickness of the temporal area was a new associated factor of TWF in addition to the previously reported age, sex, temporal bone thickness, and temporal bone density. The results implied that measuring the soft tissue thickness of the temporal area for patients with suspected TWF would be useful to clinically identify the measurement error due to a technical problem.