Ultrasound shear wave elastography of skin in diagnosis of lymphedema of lower extremity: a preliminary study
10.3760/cma.j.cn441206-20240129-00032
- VernacularTitle:皮肤剪切波弹性成像诊断下肢淋巴水肿的探讨
- Author:
Jiaping LI
1
;
Jia LUO
;
Manying LI
;
Jian QI
;
Xiang ZHOU
;
Qiushuang LI
;
Shaozhen CHEN
;
Xiaoyan XIE
;
Yanling ZHENG
Author Information
1. 中山大学附属第一医院超声医学科,广州 510080
- Keywords:
Lymphedema;
Ultrasound;
Shear wave elastography;
Skin of limbs;
Ultrasound gel pad
- From:
Chinese Journal of Microsurgery
2024;47(4):382-387
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore a better measurement mode of shear wave elastography (SWE) in the skin of lymphedema limbs, and to test its diagnostic efficacy in lymphedema.Methods:Between 1st and 10th August, 2023, 22 healthy volunteers were recruited in the Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ulrasound, the First Afiliaed Hospital of Sun Yat-Sen University to measure the Young's modulus (E-value) of limb skin by SWE using a gel pad (GP group) and the thick-layer coupling gel (CG group) respectively. Then between 15th August and 28th September, 2023, 11 patients with 13 lower limb lymphedema, who were treated in the Department of Microsurgery, Orhopaedic Trauma and Hand Surgery, the First Affiliaed Hospital of Sun Yat-Sen University, were consecutively enrolled to find out the E-value of skin in oedematous limbs. The receiver operating characteristic curve (ROC) was constructed and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated to evaluate the diagnostic efficiency. SPSS 26.0, R studio and GraphPad Prism 8 software were used for statistical analysis. Paired sample non-parametric test (Wilcoxon signed rank test) was used to compare the difference in E-value between the 2 groups. P<0.01 was considered statistically significant. Spearman correlation test was used to analyse the correlation of E-value values between the GP group and CG group. Results:Overall, it was found from the healthy volunteers that E-value of skin in distal limbs were higher than that in proximal limbs, especially in lower extremities. E-value of all scanned location in GP group were found higher than those of CG group with statistically significant difference ( P<0.01), and the values of interclass correlation coefficient (ICC) showed a good repeatability. The 11 patients with lymphedema in 13 lower extremities were examined with the thick-layer coupling gel. The skin E-value in calf of patients with lymphedema were significantly higher than that of the healthy volunteers ( P<0.01), except the skin of thighs ( P>0.01). A lymphedema was diagnosed while either a skin E-value was 27.6 kPa calculated by Youden index or with the thickness of skin was 2.3 mm. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy in the diagnosis of a lymphedema were found at 92.3%, 100%, 100%, 95.7% and 97.1%, respectively. The area under curve (AUC) of ROC was 0.962. The correlation coefficients (R) of E-value in arm, forearm, thigh and lower leg in the GP group and CP group were 0.665, 0.882, 0.850 and 0.815, respectively, which were all significantly correlated. Conclusion:Application of thick layer coupler in ultrasound skin SWE is highly feasible, and the combination of ultrasound skin SWE and skin thickness has higher diagnostic efficiency in the diagnosis of lower extremities lymphedema. It allows more accurate ultrasonic image technical support for early monitoring and diagnosis of lymphedema, microsurgical treatment and a quantitatively perioperative evaluation.
