Max Denis – denis.max@mayo.edu     507-266-7449
Mohammad Mehrmohammadi – mehr@wayne.edu
Pengfei Song – song.pengfei@mayo.edu
Duane D. Meixner – meixner.duane@mayo.edu
Robert T. Fazzio – fazzio.robert@mayo.edu
Sandhya Pruthi – pruthi.sandhya@mayo.edu
Shigao Chen – chen.shigao@mayo.edu
Mostafa Fatemi – fatemi.mostafa@mayo.edu
Azra Alizad – alizad.azra@mayo.edu   507-254-5970

Mayo Clinic College of Medicine
200 1st St SW
Rochester, MN 55905

Popular version of paper 2pBA14
Presented Monday morning, October 28, 2014
168^th ASA Meeting, Indianapolis

Currently, a large number of patients with suspicious breast masses undergo biopsy, more than half of which turn out to be benign. The huge number false positive cases results in an enormous unnecessary cost plus psychological and physical trauma to patients. To avoid such biopsies, one needs to use a modality that can better differentiate between the benign and malignant lesions.

Palpation, the examination of tissue through the use of touch, remains one of the simplest yet effective methods for detecting breast tumors. However, the sense of touch is not sensitive enough to detect small or very deep lesions. It is well known that breast tumors are often much harder than the normal tissue, and cancerous masses are harder than the benign ones [1]. Therefore, scientists have been trying to develop new imaging tools that are sensitive to tissue stiffness. Elasticity medical imaging is an emerging field that provides information about a tissue’s stiffness property [2].

This paper presents application of a new tool called “Comb Push ultrasound elastography (CUSE)”, developed in our ultrasound laboratory at Mayo Clinic Rochester [3,4,5] for accurate measurement and imaging of breast mass stiffness. This new tool will help improving detection and differentiation of breast masses, which will eventually help physicians in better diagnosis of breast cancer. We attempt to assess a tissue’s stiffness property noninvasively by applying ultrasound to tap on breast mass and determine its stiffness by measuring the speed of the resulting waves. These waves are called shear waves. Thereafter, a two-dimensional shear wave speed map is reconstructed. Having already identified the region of interest from the ultrasound, the shear wave speed map is overlaid onto the ultrasound image. Therefore, the shear wave speed within the breast mass can be measured which allows us to determine the stiffness of the mass.

Figure 1. Examples of CUSE evaluations of (a) benign and (b) cancerous breast masses.

Hence, the CUSE imaging technique may be useful as a noninvasive method as an adjunct to breast ultrasound for differentiating benign and malignant breast masses, and may help in reducing the number of unnecessary biopsies. This ongoing project is being done under an approved protocol by Mayo Institutional Review Board and funded by grants and R01CA148994- R01CA148994-04S1 from National Institute of Health and is led by Dr. Azra Alizad.

References:

1. Sewell CW (1995) Pathology of benign and malignant breast disorders. Radiologic Clinics of North America 33: 1067-1080.
2. Sarvazyan A, Hall TJ, Urban MW, Fatemi M, Aglyamov SR, et al. (2011) An overview of elastography–an emerging branch of medical imaging. Current medical imaging reviews 7: 255.
3. Song P, Manduca A, Zhao H, Urban MW, Greenleaf JF, et al. (2014) Fast Shear Compounding Using Robust 2-D Shear Wave Speed Calculation and Multi-directional Filtering. Ultrasound in medicine & biology 40: 1343-1355.
4. Song P, Urban MW, Manduca A, Zhao H, Greenleaf JF, et al. (2013) Comb-push Ultrasound Shear Elastography (CUSE) with Various Ultrasound Push Beams.
5. Song P, Zhao H, Manduca A, Urban MW, Greenleaf JF, et al. (2012) Comb-push ultrasound shear elastography (CUSE): a novel method for two-dimensional shear elasticity imaging of soft tissues. Medical Imaging, IEEE Transactions on 31: 1821-1832.