High specificity of spectral and power Doppler ultrasonographic nail
assessment in psoriatic arthritis patients
Abstract
Introduction: The use of high resolution ultrasonography (US) became a
very important tool in nail assessment. This study evaluated nails
clinical and ultrasound measurements in the psoriatic arthritis (PsA)
patients and control groups. Methods: A cross sectional study was
performed and 44 patients with PsA, 10 health individuals and 6 hand
osteoarthritis patients (OA) were selected. PsA patients were included
when filling the CASPAR criteria. Results: spectral Doppler (sD) was
analyzed in 208 nail beds. Nail plates appearance on gray scale (GS)
showed loss of the normal three-layered appearance in 89 nails (45.9%).
Power Doppler (PD) signal was detected in 189 nail beds (92.2%),
showing inflammatory activity in most of the patients and nails
examined. Resistance index (RI) measured was significantly lower in PsA
patients as compared with controls group in both longitudinal and
transverse planes (p<0.001). The nail enthesitis was observed
when RI values below 0.4, characterizing 100% sensitivity and 96%
specificity (p<0.01). Conclusions: Nail US measurements
presented statistical significance in PsA patients, in studies future
could show many inflammatory situations, as treatment assessment.