Obtaining 2D Images Of Breast Data In Sagittal Plane From Automated Whole Breast Ultrasound Screening

Abstract:- Three dimension (3D) ultrasound image reconstruction using two dimension (2D) images has attracted much attention in medical research because it provides interactive feedback to help clinicians acquire high-quality images and thus became a famous method for analyzing some anatomy related to abnormalities. In comparison to 2D ultrasound, although 3D offers tremendous benefits, there are sufficient limitations in 2D ultrasound which 3D ultrasound can potentially overcome. In this paper, 2D images of breast data in sagittal plane were obtained from Automated whole breast ultrasound screening (AWBUS)

Keywords:- Breast cancer, AWBUS, 2D ultrasound, 3D ultrasound, sagittal plane, coronal plane

Introduction

Breast cancer is most commonly occurring cancer in women, after skin cancer, it is the most common cancer diagnosed in women. Breast cancer can occur in both men and women but it’s far more common in women. There were over 2 million cases in 2018 and it is estimated that more than 40,000 deaths have been reported in only United States in 2018 due to breast cancer. The American Cancer Society’s estimates for breast cancer in United States for 2019 are:

About 268,800 new cases of invasive breast cancer will be diagnosed in women.

More than 62,000 new cases of carcinoma in situ (CIS) will be diagnosed (CIS is non-invasive and is the earliest form of breast cancer).

About 41,760 women will die from breast cancer.

Generally breast cancer starts when the cell in the breast began to grow out of control, this cells usually form a tumor that can be seen on an X-ray or felt as a lump. The tumor is malignant (cancer) if the cells can grow into (invade) surrounding tissues or spread to distant areas of the body. Breast cancer mostly spreads when the cancer cells get into the blood system and are carried to other different parts of the body. Detected early, breast cancer is easier to treat, with fewer risks and reduces mortality by 25%. This early detection can be achieved by subjecting women at risk.

Breast Cancer Detection

Despite so many progress in detecting and identifying risk factors and genetic markers for breast cancer, nearly 70–80% of cases occur in women without known major predictors[1]. Therefore, population-based screening for early detection of breast cancer is the primary strategy for reducing breast cancer mortality[2]. Various types of tests are performed to look for and diagnose breast cancer.

Mammograms

Breast Ultrasound

Breast MRI scan

AWBUS/IBUS

Mammograms

A mammogram is a low dose x-ray used to look for changes in breast tissue. It is the standard imaging method for breast cancer screening [3] and has resulted in reduced breast cancer mortality. Mammogram can often find or detect breast cancer in early stage, when it’s small and even before a lump can be felt.

Breast Ultrasound

Breast ultrasound imaging test that uses sound waves to make a computer picture of the inside of the breast. It is useful for looking at some changes in breast such as lumps especially those that cannot be see on on mammograms. Ultrasound is very useful as it can tell the difference between fluid-filled cyst (which is unliked to be cancer) and solid masses (can be cancer) also ultrasound is cheap, widely available.

Breast MRI scan

Breast MRI (Magnetic Resonance Imaging) uses magnetic rays and radio waves to create a detailed picture of inside a breast. It is often used on the women who already have been diagnosed with breast cancer and is used to measure the size of the tumor along with looking for other tumors in the breast. Although, MRI can find some cancers which cannot be seen on mammograms but it is more likely to find something that turns out not to be cancer (called false positive). Thus, MRI is not recommended as a screening test for breast cancer.

Automated Whole Breast Ultrasound Scanner (AWBUS)

Mammography as the standard imaging method for breast cancer screening has resulted in reduced breast cancer mortality. However, the number of cancers escaping detection with mammography is substantial, particularly in dense-breasted women, with sensitivity as low as 30–48%[3]. To overcome this problem of sensitivity, Automated Whole Breast Ultrasound (ABUS) is used in addition to a mammograms.

The ABUS is an FDA-approved noninvasive, radiation-free procedure used in addition to a mammogram to increase the accuracy of breast cancer screening in asymptomatic women with dense breast tissue. This painless procedure helps our physicians evaluate dense breast tissue more accurately, using sound waves to create 3D images of the breast. ABUS has been shown to improve the detection rates for breast cancer when used in addition to a mammogram[5].

IBUS

Intelligent Breast full-volume Ultrasound (IBUS), is a new and cutting-edge breast ultrasound instrument. It is a major breakthrough in the field of ultrasound imaging and diagnostic mode. It is safe and comfortable, has high image resolution, and effectively reduces missed diagnosis. It is especially suitable for Asian women's breast examination.

IBUS system can obtain multi-faceted, multi-angle, multi-directional information, especially sagittal surface scan, which can visually reveal the anatomy of breast tissue during supine position in patients, these information helps surgeons perform more accurate surgical planning.

Parameters/Working

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Do not mix complete spellings and abbreviations of units: “Wb/m2” or “webers per square meter”, not “webers/m2”. Spell out units when they appear.

• IBUS vs Traditional Ultrasound Methods
• No x-ray radiation required
• Shortened insliection time
• Higher detection rate for dense breast
• Imliroving the diagnostic accuracy of benign and malignant tumors
• The field view is more than three times larger than traditional two-dimensional lirobe
• Full volume of breast tissue can be easily obtained
• Easy to obtain water level, images of different lilanes such as transverse and coronal.

Motivation

According to GLOBOCAN 2008, although breast cancer is thought to be a disease of the developed world, but almost 50% of breast cancer cases and 58% of deaths occur in less developed countries. Belgium had the highest rate of breast cancer in women with the rate of 113. 2 per 100,000, followed by Luxembourg and Netherlands respectively.

Incidence rate has huge variation around the world from 19. 3 per 100,000 women in Eastern Africa to 89. 7 per 100,000 women in Western Europe. Same as incidence rate the survival rate of breast cancers also varies greatly all around the world, ranging from 80% or above in developed countries such as North America, Sweden and Japan to around 60% in the developing countries (middle income countries) and less than 40% in low income countries. The low survival rate in less developed and undeveloped country is mainly due to lack of early detection programme, as well as lack of proper diagnostic and treatment facilities.

Data Acquisition

This first stage, performed by the medical imaging hardware which is IBUS/AWBUS, samples some property in a patient and produces multiple 2D slices of information [6]. The data sampled depends on the data acquisition technique. IBUS is able to produce up to 700-800 image slices of the breast in sagittal plane. Each slice representing each side of the object, for example the very right, middle and leftmost part of the breast. The difference between the three sets of the image: the more the number of images in the set, the more the object area that can be covered[7]. However, as the images are obtained using this method, the error by lighting affection, which is common problem on 3D image reconstruction will be ignored.

Image Preprocessing

IBUS ultrasound images not only show breast, but also the other objects such as chest wall. Preprocessing is used to refine and clean the image by removing unneeded or unnecessary parts of the image that can be referred as noise [8]. Preprocessing steps includes Resizing, Smoothing, Filtering, Enhancement and Reduction to minimize the noise so as to produce finer images and accurate [9], [11]. Some image processing functions used in the preprocessing stage includes a Gaussian filter, Binary thresholding, Area Filtering, as well as Erosion and Dilation.

Gaussian filter is used to blur the image to remove unwanted small dots,lines. Binary thresholding is used to remove the parts of image which are of no use. Contour Area Filtering as well as Erosion and Dilation also eliminate part of the image, but refers to the size of the pixel area of the section[7].

Model Creation

After preprocessing the images the next step is model creation, Suppose, there are total ‘N’ sagittal plane AWBUS images with length ‘L’ and width ‘W’, then the volume of 3D IBUS model will be -

V = N x L x W

Since the size (length, width) of all the images are same, and images are sequentially arranged in sagittal plane, the 3D model can be directly created by stacking or placing ‘N’ images one over the another sequentially.