Novel Artificial Intelligence Guided Non-expert Compression Ultrasound Deep Vein Thrombosis Diagnostic Pathway May Reduce Vascular Laboratory Venous Testing

Abstract

Objective: Ultrasonography and D dimer testing are established modalities for evaluating potential lower extremity deep vein thrombosis (DVT). The ThinkSono Guidance system is an artificial intelligence (AI) based software allowing non-ultrasound trained providers to perform compression ultrasounds for evaluation by remote interpreters. This study evaluated its clinical use and potential reduction of venous duplexes and waiting times.

Methods: Patients with suspected DVT were prospectively recruited through the institution's emergency department. Patients underwent an AI guided two region proximal DVT compression examination by non-ultrasound trained providers using the ThinkSono Guidance system and D dimer testing. Ultrasound images remotely reviewed by the on call radiologist were rated for diagnostic quality; all images of sufficient quality were assessed as either "Compressible/no proximal DVT" or "Inadequate imaging/possible DVT". All patients assessed as "compressible" with negative D dimers were discharged. All other patients were sent for a venous duplex scan. Time to diagnosis, sensitivity, and specificity of ThinkSono Guidance against D dimers and full duplex scans were calculated.

Results: Fifty three patients (mean age 56 ± 18 years, 45% female) were scanned with ThinkSono Guidance by one of three non-ultrasound trained providers. All scans were of diagnostic quality. ThinkSono Guidance with radiologist review yielded 45 negative DVT diagnoses (85%). Seventeen of these with negative D dimers were discharged (32%) and 28 required duplex ultrasound testing per trial protocol (23 due to positive D dimers, five due to D dimer non-availability). All of these duplexes were negative (100% sensitivity). Eight patients were suspected of having DVT by the reviewing radiologist, and duplex confirmed DVT in six patients (96% ThinkSono Guidance specificity, 36% D dimer specificity). ThinkSono Guidance scans averaged 6.75 minutes for scan and review. The median time from scan initiation to review was 37.5 minutes.

Conclusion: This study suggested that a significant proportion of patients with suspected DVT could safely avoid duplex ultrasound and D dimer testing using the ThinkSono system, setting the basis for a novel AI assisted diagnostic pathway.

Keywords: Artificial intelligence; Deep vein thrombosis; Duplex ultrasound; Venous thromboembolism.