Breast imaging

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BREAST IMAGING

BREAST IMAGINGDr. Sayan

How to locate tumor from a MMG?Dist b/n benign and malig mass1

Timeline of Breast Imaging1950s Breast Self Examination1960s BSE + Mammography1970s BSE + Mammography + Thermography + Ultrasound1980s BSE + Mammography + Better US1990s BSE + Mammo + US + MRI2000s Digital Mammo + US + MRI2020?? Digital Mammo + US + MRI + MR spectroscopy + Tomosynthesis + PEM + BSGI

1913 - Albert Salomon Laid the foundations of mammography3000 mastectomy specimen Collaboration of macroscopic anatomy with microscopic examinations.1963 - 1966: Health Insurance Plan (HIP) of New York First RCT- periodic screening with physical examination & mammography. 1/3rd reduction in mortality at 5 yrs f/u & sustained benefit till 18 yrs of f/uIn 1965: 1st mammography unit the Snographe was built by Compagnie Gnrale de Radiologie headed by Charles GrosMammography : History

The Health Insurance Plan trial provided the foundation and scientific basis for the subsequent worldwide success of screening mammography In 1913, Salomon compared X-rays of the breasts to the actual removed tissue, observing specifically microcalcifications. By doing so, he was able to establish the difference as seen on an X-ray image between cancerous and non-cancerous tumors in the breast

Mammography is a special type of X -ray imaging - to create detailed image of the breast.

Permit earlier detection of abnormality

High contrast resolution is required - attenuation diff. between normal & diseased breast tissue is so small

Mammography

X-ray tube Compression deviceImage detector

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Film/Screen MammographyOld methodThe image is created directly on a film-Non modifiable

Less sensitive for women with dense breasts

10 - 20 % of breast cancers that are detected by physical examination are not visible on film mammography

A major limitation of film mammography is the film itself quality depends on exposure

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Digital Mammography Electronic (digitised) image of the breast - stores it directly in a computer

Can be manipulated

Less radiation exposure than film mammography

Improvement in image storage and transmission

Cost 1.5 to 4 times more than film systems

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Advantages of Digital MammographyExposure can be tailored to enhance tissue contrastFaster image acquisitionShorter examination timeImproved contrastBetter delineation of parenchyma & subcutaneous tissue ReproducibilityElectronic transmission ( Tele-mammography)Less storage spaceNew advancesCAD- Computer Aided DetectionDual energy subtractionContrast subtraction digital mammography

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Digital Mammography

Basic positioning CranioCaudal View

From above a horizontally-compressed breast

Will show as much as possible of glandular tissue surrounded by fatty tissue and the outermost edge of chest muscle

Nipple will be shown in profile.

Can't capture much of armpit and upper chest

From above a horizontally-compressed breast Will show as much as possible of your glandular tissue the surrounding fatty tissue and the outermost edge of chest muscle Nipple will be shown in profile. Can't capture much of the breast tissue - armpit and upper chest

Medio-Lateral Oblique view

From the side and at an angle of a diagonally-compressed breast

The angle allows more of breast tissue to be imaged including tissue in armpit.

It will show glandular as well as fatty tissue

Gives a larger area than a CC view

Other Views May be Taken for a Diagnostic Mammogram

Latero-medial (LO) - from the outside towards the center

Medio-lateral (ML) - from the center towards the outside

Spot compression - compression on only a small area, to get more detail

Cleavage view - both breast compressed, to see tissue near the center of the chest

Magnification - to see borders of structures and calcifications

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Why Use So Much Compression?Holding breast away from chest wall permits projection of most tissue & decreases noise from chest wall structureless motion results in clearer edges (less blurring)Decrease in dose due to reducing thickness thro which radiation has to passSeparates overlapping structurePressing close to detector minimizes geometric unsharpnessMore uniform thickness and uniform exposureAccurate registration of image for computer reconstruction algorithm

The compression force should be firm but should not cause pain; preferably should not be more than 20 N

Poulos et al. Breast compression in mammography: How much is enough? Australasian Radiology Volume 47, Issue 2, pages 121126, June 2003

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MammographySENSITIVITY67% (60-78%)SPECIFICITY94% (93-96)PPV8.6 (3-16)NPV99.7% (99.6-99.9)

23000 3.2 YRS MFU 176-1ST SCREEN 206 TOTAL100000 AUSTRALIA

Sensitivity overall 67%, but lower in

Young, dense breastsHormonal therapyMucinous, lobular pathologiesHigh grade or high proliferative indicesShort interval

Screening Mammographyin the average risk woman

14Truly indicate among all diseased (True Pos/ all diseased)

Specificity overall 94%, but lower in

Young, dense breasts, Hormonal therapyBIRADS not usedPrior breast surgeryBMI

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