Background Contrast enhanced ultrasonography (CEUS) may be superior to power Doppler US in detecting synovial inflammation by visualizing and quantifying low velocity blood flow at the microvascular level, thus making possible the differentiation of active synovitis from inactive intra-articular thickening. Time-intensity curve (TIC) parameters are descriptive and offer an objective quantification of vascularization in a specific anatomical area. Currently, the role of CEUS in daily rheumatological clinical practice is not well defined. [1,2] It is still not clear which CEUS abnormalities are of special interest for rheumatologists.
Objectives The main objective of our study was to compare TIC parameters of CEUS at four joint levels in early arthritis (EA) patients having wrist involvement, with the purpose of characterizing CEUS parameters uniformity. As a secondary objective, we aimed to identify which TIC parameters vary most in the examined joints.
Methods Patients diagnosed with active early rheumatoid or undifferentiated arthritis on the basis of the 2010 ACR/EULAR classification criteria, having bilateral wrist arthritis and both radiocarpal (RC) and intercarpal (IC) synovial hypertrophy identified by grey scale US, were consecutively enrolled. CEUS was performed using a second-generation contrast agent and quantified using dedicated software. The examinations started with the dominant hand. After 30 minutes, the other hand was examined, using the same protocol. The region of interest (ROI) was selected as the area corresponding to the synovial hypertrophy of the RC and IC joints. TIC parameters were calculated for the first minute of contrast enhancement and were analyzed in each of the four examined joints.
Results Nineteen patients were included in the study. Right hand dominance was present in 94.7% of patients. Dominant hand expressed higher peak, AUC and slope values, compared to the other hand. The percentage difference of the parameters measured at right IC and the other joints varied between 12–32% for Peak (p=0.007), 22–38% for AUC (p=0.015) and 9–30% for slope (p=0.514). No differences for any of the TIC parameters between the other assessed joints were found.
Conclusions CEUS behaviour was not uniform in the wrists joints of EA patients, TIC parameters revealing the highest degree of inflammation at IC joint of the dominant hand. Peak and AUC in CEUS, measured at this joint level, demonstrated the highest variation when compared to the other examined joints, suggesting their potential value for quantification of synovial inflammation.
Klauser AS, et al. Contrast-enhanced ultrasonography for the detection of joint vascularity in arthritis-subjective grading versus computer-aided objective quantification. Ultraschall Med. 2011 Dec;32 Suppl 2:E31–7.
Platzgummer H, et al. Quantification of synovitis in Rheumatoid Arthritis: Do we really need quantitative measurement of contrast-enhanced ultrasound? European Journal of Radiology 2009;71:237–41.
Acknowledgement The research was performed with financial support of the European Social Fund, Human Resources Development Operational Programme 2007–2013, POSDRU grant no. 159/1.5/S/138776.
Disclosure of Interest None declared