Evaluation of 3D shearwave(tm) elastography and its benefits for the characterization of breast lesions

Transcription

1 Evaluation of 3D shearwave(tm) elastography and its benefits for the characterization of breast lesions Poster No.: C-2280 Congress: ECR 2011 Type: Scientific Paper Authors: D. AMY; Aix en Provence/FR Keywords: Breast, Oncology, Ultrasound, Elastography DOI: /ecr2011/C-2280 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 26

2 Purpose This analysis presents the results of a fifty-patient study related to the evaluation of the TM performance of 3D ShearWave Elastography (SWE) and 3D B-mode as compared to 2D ultrasound imaging for breast lesion characterization. TM ShearWave Elastography is a breakthrough technology that gives important information about tissue elasticity [1-2-3]. Unlike conventional elastography methods, which rely on manual compression and measure tissue displacement, ShearWave Elastography requires no manual compression and computes true tissue elasticity by measuring the velocity of shear waves as they propagate in tissue. Shear wave propagation speed in tissue is directly related to tissue stiffness. This technology relies upon the generation of a shear wave and its subsequent capture. Shear wave propagation speed is then calculated and a color-coded real time ShearWave Elastography map is produced showing tissue stiffness. Results are real-time, user-skill independent, reproducible and quantifiable in kilopascals or meters per second. 3D Breast ultrasound offers a new approach to breast imaging and improves the diagnosis of breast lesions. The 3D volumetric data acquired, combined with advanced 3D display rendering brings new information and new visualization of breast lesions. Lesions can be visualized in any plane of the 3D volume and particularly in the coronal plane or C-plane. Looking at the lesion in the coronal plane leverages additional criteria and feature for lesion characterization. Modified pattern and Spiculation/Star pattern add additional confidence to the lesion malignancy [4-5]. TM 3D ShearWave Elastography brings new information for the characterization of breast lesions. In a single 3D acquisition, Aixplorer produces 2 complementary volumes with all the necessary information for the volumetric assessment of the lesion: A 3D B-mode high resolution volume for characterization and morphological assessment of the lesion and a 3D elastography volume providing local information of the elasticity distribution inside and around the lesion. Typically, a high resolution B-mode volume is acquired in less than 3s and in less than 10s for the combined B-mode/SWE 3D volumes. Methods and Materials This study was approved by the French National Committee for the Protection of Patients Participating in Biomedical Page 2 of 26

3 Research Programs. All patients signed a written consent form. Using the Aixplorer ultrasound system (SuperSonic Imagine, Aix en Provence, France) conventional 2D Bmode and 2D quantitative SWE images were performed. 2D features were described and lesions were BI-RADS -scored. Lesions included 13 BIRADS 5 and 37 followed-up BI-RADS 2, of which 24 were fibro adenomas and 13 cystic structures. 3D B-mode and 3D SWE volumes were acquired for each lesion. BI-RADS features were also assessed from 3D B-mode. SWE size of the lesion was measured as well as elasticity in kilopascals. 3D data was displayed in MPR and coronal plane multi-slice views to report lesion morphology. Results The following results are from 3 cases of the study: The first case is benign BI-RADS 2 lesion The second and third cases are confirmed BI-RADS 5 lesions. Case 1 Case 1 is a patient of 52 years old. She presented a solid lesion on the right breast: Ovoid shape and very well circumscribed, homogeneous with a poor internal vascularization. No modification in the surrounding tissue: BI-RADS 2. Page 3 of 26

4 Fig.: Figure 1 : 2D B-mode image of the case 1 fibro adenoma References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE Page 4 of 26

5 Fig.: Figure 2: 3D B-mode MPR reconstruction of case 1 fibro adenoma References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE Figure 1 and 2 demonstrate very good correlation between 2D and 3D acquisitions. Furthermore, the dimensions acquired from 2D and 3D on the lesion are identical. Page 5 of 26

6 Fig.: Figure 3 : 2D ShearWave Elastography image of case 1 fibro adenoma. SWE information is color coded between 0 and 180 kpa. References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE Page 6 of 26

7 Fig.: Figure 4 : 3D ShearWave Elastography MPR reconstruction of case 1 fibro adenoma References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE From figures 3 and 4, we can observe a very good correlation between the quantitative elasticity values measured in 2D and 3D on the same lesion and on planes that are spatially at the same position. The elasticity ratio measuring the elasticity inside the lesion divided by the elasticity of the fat is 2.7 on the 2D SWE image and 2.9 on the 3D SWE data. Elasticity maps on both 2D and 3D images are homogeneous with no particular modification in the tissue, which correlates with the benign assessment of the lesion. Case 2 Case 2 is a patient of 58 years old. She presents with a palpable mass on the right breast. 2D B-mode image shows a hypoechoic spiculated millimetric mass: BI-RADS 5. The pathology result confirms an invasive intraductal carcinoma. Page 7 of 26

8 Fig.: Figure 5: 2D ShearWave Elastography image of case 2 invasive intraductal carcinoma References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE Page 8 of 26

9 Fig.: Figure 6 : 3D ShearWave Elastography MPR reconstruction of case 2 invasive intraductal carcinoma References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE The 2D and 3D ShearWave elastography images on this case present with high heterogeneity and high elasticity values up to 180kPa. On both 2D and 3D images, we can observe that the elasticity modifications appear in the surrounding area of the lesion, whereas the center remains at low elasticity values around 35 kpa. Page 9 of 26

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11 Fig.: Figure 7: 3D ShearWave Elastography MultiSLice coronal plane reconstruction of case 2 invasive intraductal carcinoma. 0% SWE transparency (top figure) and 50% SWE transparency (bottom figure). References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE Figure 7 presents a MultiSlice reconstruction of the 3D volume acquired with B-mode and SWE. Each plane corresponds to a different depth as compared to the skin layer. On the B-mode we can observe the carcinologic modifications of the surrounding tissue with a spiculated characteristic pattern. On the bottom figure, the SWE elasticity areas with high values correlate perfectly with the B-mode aspects. The MultiSlice display on the coronal plane brings more accurate information for lesion delineation as well as a better understanding of surrounding tissue modification. Case 3 Case 3 is a patient of 65 years old. She presents with a palpable mass on the left breast. 2D B-mode images show several hypoechoic spiculated millimetric masses :BI-RADS 5. The biggest lesion is hyper-vascularized with irregular and heterogeneous internal structures. The pathology result confirms an invasive carcinoma. Page 11 of 26

12 Fig.: Figure 8: 2D ShearWave Elastography image of case 3 invasive carcinoma References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE Page 12 of 26

13 Fig.: Figure 9: 3D ShearWave Elastography MPR reconstruction of case 3 Invasive carcinoma References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE Figure 9 shows that the elasticity modifications for this lesion are both in the middle of the cancer itself as well as in the surrounding tissue. Shear wave elastography highlights that the elasticity modifications are not only on the border but also in all the surrounding fibrotic and fatty structures. Page 13 of 26

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15 Fig.: Figure 10: 3D ShearWave Elastography MultiSLice coronal plane reconstruction of case 3 invasive carcinoma. 0% SWE transparency (top figure) and 50% SWE transparency (bottom figure). References: D. AMY; Radiology, Cabinet de Radiologie, Aix en Provence, FRANCE On figure 10, the identical characteristic features are found as in case 2. The B-mode coronal planes reinforce the cancer signature with the heterogeneous spiculated aspect. The ShearWave Elastography slices have the typical signature of a BI-RADS 5 lesion. On all lesions, imaging performances of 3D data were identified at least as good as 2D images. Very good agreement was observed between 2D and 3D BI-RADS features. 3D B-mode demonstrated a better ability to delineate breast masses from the surrounding tissue thanks to the coronal plane visualization. 2D and 3D SWE quantitative and qualitative results were comparable. 3D SWE offered a better visualization of the elasticity in the surrounding areas in addition to a higher delineation and morphological assessment of the lesion. Images for this section: Fig. 1: Figure 1 : 2D B-mode image of the case 1 fibro adenoma Page 15 of 26

16 Fig. 2: Figure 2: 3D B-mode MPR reconstruction of case 1 fibro adenoma Page 16 of 26

17 Fig. 3: Figure 3 : 2D ShearWave Elastography image of case 1 fibro adenoma. SWE information is color coded between 0 and 180 kpa. Page 17 of 26

18 Fig. 4: Figure 4 : 3D ShearWave Elastography MPR reconstruction of case 1 fibro adenoma Page 18 of 26

19 Fig. 5: Figure 5: 2D ShearWave Elastography image of case 2 invasive intraductal carcinoma Page 19 of 26

20 Fig. 6: Figure 6 : 3D ShearWave Elastography MPR reconstruction of case 2 invasive intraductal carcinoma Page 20 of 26

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22 Fig. 7: Figure 7: 3D ShearWave Elastography MultiSLice coronal plane reconstruction of case 2 invasive intraductal carcinoma. 0% SWE transparency (top figure) and 50% SWE transparency (bottom figure). Fig. 8: Figure 8: 2D ShearWave Elastography image of case 3 invasive carcinoma Page 22 of 26

23 Fig. 9: Figure 9: 3D ShearWave Elastography MPR reconstruction of case 3 Invasive carcinoma Page 23 of 26

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25 Fig. 10: Figure 10: 3D ShearWave Elastography MultiSLice coronal plane reconstruction of case 3 invasive carcinoma. 0% SWE transparency (top figure) and 50% SWE transparency (bottom figure). Page 25 of 26

26 Conclusion Shear wave elastography gives quantitative and reproducible information on solid breast lesions. Furthermore, 3D SWE is offering volumetric information for lesion characterization, especially with regards to lesion margins. As for 3D B-mode where the coronal plane analysis leverages additional criteria and feature for lesion characterization, the 3D SWE coronal plane section brings specific ultrasonic and elastographic features for the identification, delineation and extension of BI-RADS 5 lesions. 3D SWE will potentially improve characterization of breast lesions and bring new criteria for the follow-up of lesions under treatment. References [1] Bercoff J, Tanter M, Fink M. "Supersonic shear imaging: a new technique for soft tissue elasticity mapping ". IEEE Trans Ultrason Ferroelect Freq Control, 2004; 51: [2] Tanter M, Bercoff J, Athanasiou A, Deffieux T, Gennisson JL, Montaldo G, Muller M, Tardivon A, Fink M. "Quantitative assessment of breast lesion viscoelasticity: initial clinical results using supersonic shear imaging", Ultrasound Med Biol, 2008 Sep; 34(9): [3] Athanasiou A, Tardivon A, Tanter M, Sigal-Zafrani B, Bercoff J, Deffieux T, Gennisson JL, Fink M, Neuenschwander S. "Breast lesions: quantitative elastography with supersonic shear imaging--preliminary results". Radiology.,2010 Jul;256(1): [4] Cho N, Moon WK, Cha JH, Kim SM, Han BK, Kim EK, Kim MH, Chung SY, Choi HY, Im JG. "Differentiating benign from malignant solid breast masses: comparison of twodimensional and three-dimensional US". Radiology, 2006 Jul;240(1): [5] Weismann C, Hergan K. "Current status of 3D/4D volume ultrasound of the breast". Ultraschall Med Jun;28(3): Personal Information Page 26 of 26