Multimodal photoacoustic/ultrasonic imaging system: a promising imaging method for the evaluation of disease activity in rheumatoid arthritis
Chenyang Zhao, Qian Wang, Xixi Tao, Ming Wang, Yu Chen, Sirui Liu, Mengtao Li, Xinping Tian, Zhenhong Qi, Jianchu Li, Fang Yang, Lei Zhu, Xujin He, Xiaofeng Zeng, Yuxin Jiang, Meng Yang
Abstract
Abstract Objectives We aimed to assess the clinical value of multimodal photoacoustic/ultrasound (PA/US) articular imaging scores, a novel imaging method which can reflect the micro-vessels and oxygenation level of inflamed joints of rheumatoid arthritis (RA). Methods Seven small joints were examined by the PA/US imaging system. A 0–3 scoring system was used to semi-quantify the PA and power-Doppler (PD) signals, and the sums of PA and PD scores (PA-sum and PD-sum scores) of the seven joints were calculated. The relative oxygen saturation (SO 2 ) values of the inflamed joints were measured and classified into 3 PA+SO 2 patterns. The correlations between the PA/US imaging scores and the disease activity scores were assessed. Results Thirty-one patients of RA and a total of 217 joints were examined using the PA/US system. The PA-sum had high positive correlations with the standard clinical scores of RA (DAS28 [ESR] ρ = 0.754, DAS28 [CRP] ρ = 0.796, SDAI ρ = 0.836, CDAI ρ = 0.837, p < 0.001), which were superior to the PD-sum (DAS28 [ESR] ρ = 0.651, DAS28 [CRP] ρ = 0.676, SDAI ρ = 0.716, CDAI ρ = 0.709, p < 0.001). For the patients with high PA-sum scores, significant differences between hypoxia and hyperoxia were identified in pain visual analog score ( p = 0.020) and patient’s global assessment ( p = 0.026). The PA+SO 2 patterns presented moderate and high correlation with PGA ( ρ = 0.477, p = 0.0077) and VAS pain score ( ρ = 0.717, p < 0.001). Conclusion The PA scores have significant correlations with standard clinical scores for RA, and the PA+SO 2 patterns are also related with clinical scores that reflect pain severity. PA may have clinical potential in evaluating RA. Key Points • Multimodal photoacoustic/ultrasound imaging is a novel method to assess micro-vessels and oxygenation of local lesions. • Significant correlations between multimodal imaging parameters and clinical scores of RA patients were verified. • The multimodal PA/US system can provide objective imaging parameters, including PA scores of micro-vessels and relative SO 2 value, as a supplementary to disease activity evaluation.