Breast Sonoelastography: Our Preliminary Experience in 155 Lesions
MC Lam, KML Wong, WS Mak, KMK Kwok, HS Lam, CW Wong
Hong Kong J Radiol 2016;19:287-92
DOI: 10.12809/hkjr1615379
Objectives: To determine whether shear wave velocity is correlated with the ultrasound Breast Imaging–Reporting and Data System (BIRADS) grading and pathology result, and to establish a cutoff value to distinguish benign and malignant lesions.
Methods: This prospective study was conducted from November 2014 to March 2015 in a regional hospital in Hong Kong. Women with ultrasound-identified breast lesions were included. Ultrasound followed by sonoelastography was performed for all patients. Patient demographics, ultrasound findings, shear wave velocities, and cytology and histology results were analysed. Receiver operating characteristic curves were plotted to determine a cutoff value.
Results: Overall, 97 patients with 155 lesions were included. Pathology results were available for 61 benign and 27 malignant lesions. BIRADS grade 4 and 5 lesions had higher maximum (3.94 vs. 2.95 m/s; p = 0.029) and mean shear wave velocity (3.66 vs. 2.69 m/s; p = 0.023) than that of BIRADS 2 and 3 lesions. BIRADS grading had a moderate positive correlation with both maximum and mean shear wave velocity in sonoelastography (ρ = 0.304 and 0.308; both p = 0.0001). Histologically proven malignant lesions had higher maximum (5.75 vs. 2.87 m/s; p < 0.0001) and mean shear wave velocity (5.36 vs. 2.62 m/s; p < 0.0001) than that of benign lesions. Based on the 88 lesions with pathology results, B-mode ultrasound BIRADS alone had a sensitivity of 100%, specificity of 42.6%, positive predictive value of 43.5%, and negative predictive value of 100%. With a cutoff velocity of 2.98 m/s, sonoelastography achieved a sensitivity of 88.9% and specificity of 60.7%. Applying this to BIRADS 4a lesions, specificity of BIRADS improved to 73.8% while sensitivity dropped to 88.9%.
Conclusion: Shear wave velocity is correlated with ultrasound BIRADS grading and final pathology. A cutoff at 2.98 m/s achieved a sensitivity of 88.9% and specificity of 60.7% for malignancy detection.
Authors’ affiliations:
MC Lam: Department of Radiology and Organ Imaging, United Christian Hospital, Kwun Tong, Hong Kong
KML Wong, WS Mak, KMK Kwok, HS Lam, CW Wong: Department of Diagnostic and Interventional Radiology, Kwong Wah Hospital, Yaumatei, Hong Kong
中文摘要
乳腺超聲彈性成像：155個病變的初步經驗
林茂珠、黃嘉敏、麥詠詩、郭勁明、林漢城、黃鎮威
目的：探討剪力波的波速是否與超聲乳腺影像報告和數據系統（BIRADS）的分級和病理結果相關，並設立截斷值用作鑒別良惡性病變。
方法：這項前瞻性研究於2014年11月至2015年3月在香港一所分區醫院內進行。研究對象為經超聲成像證實有乳腺病變的婦女，於乳房超聲彈性成像之前，先行常規超聲檢查。分析患者人口學數據、超聲結果和剪力波的波速，以及細胞學和組織學結果。繪製ROC曲線以找出截斷值。
結果：總計97名患者的155例病變納入研究。當中61個良性和27個惡性病變有病理學結果。BIRADS 4級和5級病變的最大剪力波波速（3.94比2.95 m/s；p=0.029）和剪力波平均波速（3.66比2.69 m/s； p=0.023）均大於BIRADS 2級和3級病變。乳房超聲彈性成像方面，BIRADS分級與最大波速和平 均波速呈中度正相關（ρ=0.304和0.308，兩者皆為p=0.0001）。組織學證實的惡性病變最大波速（5.75比2.87 m/s；p<0.0001）和平均波速則更高（5.36比2.62 m/s；p<0.0001）。根據88例病理學結果，單獨運用乳房B-mode超聲BIRADS分級的靈敏度為100%，特異度42.6%，陽性預測值43.5%，陰性預測值100%。剪力波的波速截斷值為2.98 m/s時，乳腺超聲彈性成像的靈敏度可達88.9%，特異性為60.7%。將其應用於BIRADS 4a級乳腺病變，BIRADS的特異性提高至73.8%，靈敏度則降至88.9%。
結論：剪力波的波速與超聲BIRADS分級和最終病理學結果相關。剪力波的波速截斷值為2.98 m/s時，BIRADS對惡性腫瘤檢測的靈敏度為88.9%，特異性為60.7%。