ROLE OF ELASTOGRAPHY IN CHARACTERISATION OF BREAST LESIONS. ABSTRACT ID .NO: IRIA-1214 TOPIC ROLE OF ELASTOGRAPHY IN CHARACTERISATION OF BREAST LESIONS.

INTRODUCTION Breast cancer is the most common malignancy in women . The early breast cancer detection modalities such as mammography ,ultrasonography and magnetic resonance imaging have high sensitivity but low specificity. Due to overlapping sonographic features of some benign and malignant lesions, biopsies become inevitable causing discomfort to the patients and increased costs. To overcome these limitations, ultrasound elastography was introduced which has high specificity in characterization of breast lesions

MATERIALS AND METHODS PATIENTS: Breast lesions of 26 patients were analyzed by B mode ultrasound and three modes of elastography namely esie touch, virtual touch tissue imaging, virtual touch tissue quantification. TECHNIQUE: Sonographic and elastographic examinations were performed by using the ACUSON S2000 ultrasound system(siemens medical solutions, mountain view, CA,USA)with a band width of 4-9 MHZ with an integrated elastography software and ARFI technology.

ESIE TOUCH simple cyst Score1:Even strain for the entire lesion Score2:Strain in most of the lesion with some areas of no strain(mosaic pattern) FNAC: Fibro adenoma Score3:Strain at the periphery of the lesion with sparing of the center HPE: Fibro epithelial lesion Score4:No strain in the entire lesion HPE: Fibro adenoma with hyalinization score5:No strain in the entire lesion and surrounding area. HPE: Infiltrating ductal carcinoma

ARFI(VTI) Bright -cyst Intermediate-Fibro adenoma Dark - carcinoma

SHEAR WAVE VELOCITIES BENIGN LESION MALIGNANT LESION WITHIN THE LESION BORDER GLANDULAR TISSUE FAT

DISCUSSION Ultrasound elastography estimates the relative tissue stiffness in response to a stressing force : In our study esie touch is performed by a very light compression with the probe. Elastographic images were assessed by a color scale Red :the areas with no strain Green :to areas with intermediate elasticity Blue: to components with the greatest strain. Images were classified according to the 5 score system of Ueno and colleagues; Score1-Even strain for the entire lesion Score2-Strain in most of the lesion with some areas of no strain(mosaic pattern) Score3-Strain at the periphery of the lesion with sparing of the center Score4-No strain in the entire lesion Score5-No strain in the entire lesion and surrounding area. It is subjective and operator dependent ESIE TOUCH

DISCUSSION ARFI : Composed of two components VIRTUAL TOUCH TISSUE IMAGING: By using acoustic radiation forces ,to generate localised tissue displacements it generates a qualitative map depicting the relative stiffness of tissue. 1.stiff tissue appear dark 2.soft tissues appear bright VIRTUAL TOUCH TISSUE QUANTIFICATION: It quantifies the absolute tissue elasticity Calculates the propagation velocity of the shear waves through tissues induced by focused radiation force The limits for measurements of VTQ values for this machine were 0-9m/s The values outside these limits were displayed as X.XX. Stiffer tissues will have more shear wave velocities compared to softer tissues EXCEPTIONS: Soft malignant lesions such as mucinous, medullary, papillary and some infiltrating ductal carcinomas. Hard benign lesions, Hyalinised fibro adenomas and fat necrosis.

RESULTS Esie touch- strain elastography ARFI -VTI All malignant lesions in our study showed dark elastogram on VTI. Out of 14 benign lesions 11,showed intermediate and 3 showed dark elastogram which may be due to hard lesions or due to excessive compression resulting in false positives. All malignant lesions showed score 5 and benign lesions showed scores 2,3,and 4 on esie touch depending on the degree of hardness

SHEAR WAVE VELOCITIES MALIGNANT LESIONS BENIGN LESIONS Average shear wave velocities are higher with in the lesion compared to the border, which are in turn higher compared to the glandular tissue and fat respectively for both benign and malignant lesions. These values are higher for malignant lesions compared to the benign lesions.

MALIGNANT LESIONS Out of the 12 malignant lesions 2 of the BIRADS-IV category lesions were correctly upgraded to BIRADS V after using elastography

BENIGN LESIONS Out of the 14 malignant lesions 4 of the BIRADS-IV category lesions were correctly downgraded to BIRADS -III after using elastography. Two of the lesions showed false positive results as one was a hyalinized fibroadenoma and another was sclerosing intraductal papilloma.

CONCLUSION Addition of Elasticity imaging was useful because it corroborated better with histopathology and increased our confidence levels in characterization of breast lesions and reduced the need for biopsies. ACR BIRADS ATLAS Vth EDITION has added elasticity assessment as a parameter in the associated features unlike the previous editions.

RFERENCES Beatriz Navarro, MD, Belen Ubeda , MD, Merce Vallespi, MD, Casandra Wolf, MD, Lilian Casas, MD,Jean L.Browne, MD WEI MENG,GUANGCHEN ZHANG,CHANGJUN WU,GUOZHU WU,YAN SONG,ZHAOLING LU Ultrasound department,The first affiliated Hospital of Harbin Medical University ,Harbin,China;and Technology Department ,Siemens of Chindex International Inc.,China Jianqiao zhou, MD,Weiwei zhan, MD,Cai Chang ,MD, Jinwen zhang,MD, Zhifang,MD,Yijie Dong, MD,Chun Zhou,MD,Yanyan Song,phD