The Diagnostic Accuracy of Carotid Doppler in Detecting Anechoic Thrombus Against CT Angiography as the Gold Standard

Objective In this study, we aimed to assess the diagnostic accuracy of carotid Doppler ultrasound (CDU) in detecting anechoic carotid artery thrombus when compared to CT angiography (CTA) as the gold standard. Materials and methods This prospective comparative study was conducted at the Radiology Department of the Pakistan Institute of Medical Sciences, Islamabad from January 2022 to May 2022. The study enrolled 32 patients who met the inclusion criteria. We evaluated patients admitted to the neurology ward/OPD who were referred to radiology as part of a stroke workup based on their clinical examination and medical history. In all patients, CDU was used to detect free-floating thrombus (FFT)/anechoic thrombus. CTA was used as the gold standard to assess the diagnostic accuracy of CDU. Results The mean age of the study participants was 45.63 ± 7.05 years (range: 33-59 years). Out of 32 patients, 19 (59.4%) were male and 13 (40.6%) were female. The results of CDU were confirmed by CTA in all patients. The diagnostic accuracy of CDU was 53.12% for detecting FFT. The values for sensitivity (54.55%), specificity (50%), positive predictive value (PPV, 70.59%), and negative predictive value (NPV, 33.33%) were also calculated. Conclusion Despite the limited sample size, the study concludes that CDU has a diagnostic accuracy of 53%. CTA still remains the gold standard imaging modality for anechoic thrombus if strong clinical suspicion is present.