Adrian Kuok Pheng Lim MD, FRCR, Presenter: Luminary, Toshiba Corporation

Keshthra Satchithananda MBBS, Abstract Co-Author: Committee member, Johnson & Johnson

Sonya Abraham, Abstract Co-Author: Nothing to Disclose

Elizabeth Ann Dick MD, FRCR, Abstract Co-Author: Nothing to Disclose

David Owen Cosgrove MBBCh, FRCR, Abstract Co-Author: Research Consultant, SuperSonic Imagine Research Consultant, Bracco Group Speakers Bureau, Toshiba Corporation

To assess the efficacy of Superb Microvascular Imaging (SMI) in detecting low grade inflammation in joints and tendons compared with conventional Power Doppler ultrasound (PDUS).  

SMI is a new and sensitive Doppler technology designed to detect slow flowing microvasculature. We assessed it in patients who presented for routine MSK ultrasound (Aplio 500, Toshiba Medical Systems). The grey-scale, PDUS and SMI findings of each study were recorded on video clips. The joints and tendons which demonstrated an abnormality or vascular signal on either grey-scale appearance, PDUS or SMI were included in the analysis. Three radiologists with over 10 years experience individually in MSK ultrasound assessed the images and scored whether there were grey-scale changes, signal on PDUS and/or SMI within the joints or tendons examined. If signal was detected on PDUS and SMI, they also scored a four point scale comparing the two Doppler techniques (no difference, mildly, moderately or markedly better)  

50 cases have been analyzed to date, comprising of  36 joints, 9 tendons, and 5 superficial lumps. In all cases, patients were symptomatic with joint pain or a palpable lump and 12 had a history of an inflammatory arthropathy. There was very good agreement between the readers (Κappa = 0.85). 29 cases demonstrated vascular flow with both PD and SMI while in 5 cases, no flow was detected with either technique. In 16 cases, vascularity was detected with SMI but not with PDUS (Fisher's exact test: p = 0.02). Out of the 29 patients with vascularity on SMI and PDUS, 3 showed no difference; while SMI scored moderately or markedly better in 20 cases (Chi2: p<0.02). In 12 patients, the SMI findings altered patient management where they either received an ultrasound guided steroid injection or started oral analgesia and/or disease modifying treatment.  

SMI is a revolutionary Doppler technique which not only improves the visualisation of the microvasculature but allows detection of low grade inflammation not previously visualised with Power Doppler. This has significant clinical impact leading to a change in management in 25% of the patients in this study population.

The improved sensitivity of SMI compared with the current  "gold standard" Power Doppler, allows the detection of low grade inflammation not possible with Power Doppler which would significantly influence patient treatment.    

Lim, A, Satchithananda, K, Abraham, S, Dick, E, Cosgrove, D, Superb Microvascular Imaging (SMI) and Detection of Low Grade Musculoskeletal Inflammation.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007205.html