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INTRODUCTION: Carotid webs (CaW) are increasingly recognized as a cause of cryptogenic acute ischemic stroke (AIS). Due to the risk of recurrent ischemic stroke associated with CaW, it is important to identify them. Although several studies report digital subtraction angiography (DSA) and computerized tomography angiography (CTA) to be better at diagnosing CaW than Doppler ultrasound (DUS), it remains to be defined which is the best radiological method to diagnose CaW. Our aim was to evaluate sensitivity and accuracy of DUS compared to CTA for CaW diagnosis. METHODS: We searched PUBMED and EMBASE databases from inception through August 2022. We included studies with patients with CaW diagnosed by DUS and/or CTA, in which both methods were used in each patient. Demographic characteristics, diagnostic reports of each method and histology reports were collected. Descriptive analysis and sensitivity and accuracy estimates were made to evaluate DUS compared to CTA. RESULTS: We included 27 articles in the systematic review (121 patients with CaW). DUS identified 94 patients with CaW and CTA 116 patients. DUS missed diagnosis in 22.3% (27 patients) and CTA did not identified CaW detected by DUS in 4.13% (5 patients). Accuracy rate between DUS and CTA was 73.6% (95% CI 64.8 to 81.2%). Sensitivity of DUS to diagnose CaW compared to CTA was 76.7% (95% CI 68.0 to 84.1%). Most common misdiagnosis with DUS were normal exam (44.4%), atherosclerosis (22.2%) and dissection (22.2%). CONCLUSION: The sensitivity and accuracy of DUS to diagnosis of CaW were moderate. It might detect CaW in some cases in which it was not identified by CTA. Increase recognition of CaW and specific ultrasound protocols may enhance diagnosis of CaW by DUS.
RESUMO
OBJECTIVE: The aim of the work described here was to analyze the relationship between the change in ultrasound (US) settings and the vertical artifacts' number, visual rating and signal intensity METHODS: An in vitro phantom consisting of a damp sponge and gelatin mix was created to simulate vertical artifacts. Furthermore, several US parameters were changed sequentially (i.e., frequency, dynamic range, line density, gain, power and image enhancement) and after image acquisition. Five US experts rated the artifacts for number and quality. In addition, a vertical artifact visual score was created to determine the higher artifact rating ("optimal") and the lower artifact rating ("suboptimal"). Comparisons were made between the tested US parameters and baseline recordings. RESULTS: The expert intraclass correlation coefficient for the number of vertical artifacts was 0.694. The parameters had little effect on the "optimal" vertical artifacts but changed their number. Dynamic range increased the number of discernible vertical artifacts to 3 from 36 to 102 dB. CONCLUSION: The intensity did not correlate with the visual rating score. Most of the available US parameters did not influence vertical artifacts.
