Mammography

9/24/2014 online

Radiographic studies of the breast

Breast Anatomy

Breast =mammary gland

Consist of glandular, fat, and fibrous tissue

Anatomy cont’d

Female breasts are divided into 15 – 20 lobes

each made up of lobules

Supported by Cooper’s ligament which determines firmness

Lobule size

Affected by age and hormones (pregnancy)

Involution: process of decreasing lobule size with age and after pregnancy

-flatter, saggier breasts

Anatomy (cont’d)

Axillary nodes are often evaluated on mammograms

Because lymphatic vessels of breast drain into lymph nodes

Tissue Variations

Breasts consists of both glandular and connective

Ability to visualize depends on amount of fat within and around breast lobules- provides contrast

Postpuberty breasts contain primarily dense connective tissue- harder to visualize

19 yr. old (never pregnant)

(dense breast)

24 yr. old (has children)

(fatty breast)

Mammograms comparing 2 different women

Cancer in tissues of breast –ducts (tubes that carry milk to nipple)

lobules (glands that make milk)

Can men get breast cancer?

Yes, but rare 1/100 compared to women

Definition of breast cancer

Breast Cancer

Nationally the 2nd leading cause of cancer-related deaths in women

What is first?lung cancer

Breast cancer in United States in 2009 (estimated):

New cases: 192,370 (female)

Deaths: 40,170 (female)

Breast Cancer Risk increases with:

Age

Hormonal history early menses late menopause pregnancy after age 30 Never had a child

Family historyIf daughter, mother, or sister has breast cancer

Pt.s in early stages respond well to treatment

Patients with advanced disease do poorly

Earlier diagnosis, better chance of survival

Mammography is best way for early detection!

Mammography Risk vs. Benefit

In 2007, in US –

133 deaths /million from breast cancer

5 deaths/million from mammography induced radiation (using screen film mammography)

Chances are 26 times more likely that a mammogram will save you rather than harm you!

(70.1% of non-palpable lesions are non-malignant!)

What are your chances beating Breast Cancer ?

If cancer is confined to breast, there is a 97% survival rate for 5 years

Incidence of breast cancer stable since 1988-

-mortality rate decreased by 29%- mainly do to early detection

At what age should a woman have her first mammogram?

Used to be: once a year after age 40

In Nov. 2009, U.S. Preventive Services Task Force updated recommendations:

No routine screening mammography in women aged 40 to 49 years!

50-74 should have mammogram every other year

Optional every other year before age of 50 years:

individual choice based on family history and pt's weighing of specific benefits and harms

American College of Radiology and Society of Breast Imagingstrongly disagree!

Annual screening mammography should begin at age 40!

Mammography only every other year in women 50-74 would miss 19 to 33 percent of cancers that could be detected by annual screening!

History of breast cancer detection

When was the first radical mastectomy introduced?1898

What year was the radiographic appearance of breast cancer first reported?

1913

When did mammography became a reliable diagnostic tool? in 1950s when industrial grade x-ray film introduced

History of breast cancer detection cont’d

1960’s – Xerography introduced – excellent results and much lower dose than industrial film

1975 – Low- dose mammography (High speed/resolution film) introduced by DuPont-

much lower dose than xerography which was then discontinued

Thermography

Approved by United States FDA in 1983

Detects localized temperature elevations over breast

In more than 90%, a "hot spot" will show if cancer is present (all hot spots are not cancer)

A complement to mammography only-

Can only spot superficial hot spots

MQSA (Mammography Quality Standards Act)

1992 – MQSA passed by Congress, not enacted until 1994

Mammography became 1st and only federally regulated imaging exam, which mandated:

Formal training and continuing education

Required regular inspection of equipment

Documentation of quality assurance

Report results, follow-up, track pts, and monitor outcomes

Types of Mammograms

Baseline mammogram: very 1st mammogram (or 1st mammo. after surgery)

Screening mammogram: all mammos after baseline- if pt. asymptomatic (no known breast problems)

Diagnostic Mammogram: when woman presents with clinical evidence of:

Breast disease

Palpable mass or other symptom

Typical Mammography Unit

Equipment is C-arm

SID is fixed at 24 – 26”

Mammography Equipment

1st dedicated mammography unit -1969

Designed to produce high-contrast and high-resolution images

More precise control of kVp, mA, and exposure time

Low kVp : 25 – 28

AEC (automated exposure control)

Grid with ratio: 4:1, or 5:1 200 lines/inch

Mobile Mammography Van

Inexpensive Screening Mammograms can be obtained when it comes to your area

Screen-Film Systems

Now largely replaced by digital imaging

Mammography cassettes contain a single screen

Film is single emulsion

Extended time processing can be usedto reduce dose and increase contrast

Digital MammographyState of the art!

No film, no chemical processing

Much better definition

Less compression needed

Radiation dose about 22% less

Fewer repeats do to poor technique selection

Digital mammography cont’d

Images easily sent over internet

Can give pt. CD of images

Possible downside:1st digital images compared to

previous film images can give false positives due to increased sensitivity

Procedure

Complete, careful history and physical assessment!

Take notes on location of scars, palpable masses, skin abnormalities, and nipple alterations

Examine previous mammograms for positioning, compression, and exposure factors

Procedure (con’t)

Have Pt put on gown with opening in front

Breasts must be bared for imagingCloth will cause image artifact

Remove deodorant and powder from axilla and breast:

It can mimic calcifications on image!

Procedure (cont’d)

Explain procedure to pt., including possibility for additional projections

Consider natural mobility of breast before positioning

Support breast firmly so that nipple is directed forward in profile

Apply proper compression

Place ID markers

Purpose of Compression (25-40 lbs!)

Decreases thickness of breast- thus reduces exposure dose

Decreases magnification and scatter

Increases contrast

Reduces motion unsharpness

MagnificationDigital Mammography now makes “mag films” obsolete

Uses increase OID to magnify image

Increases visibility of small structures

Why does Radiation dose increase with magnification even though technique is not increased?-(breast is closer to source)

Routine Mammography Projections and Positions

Routine mammography projections

Craniocaudal (CC)

Mediolateral oblique (MLO)

Craniocaudal ProjectionPt position

Standing or seated facing IR holder

Part positionElevate inframammary fold to maximum height

Adjust IR height to inferior surface of breast

Gently pull breast onto IR holder with both hands while instructing pt to press chest to IR holder

Craniocaudal Projection (cont’d)

Rotate head away from breast being examined (watch out for hair!)

Lean pt. toward machine

Move opposite breast out of the way

Place hand on shoulder and slide skin over clavicle

Compress breast slowly until skin taut

Mediolateral Oblique Projection

PositionCenter breast with nipple in profile

Hold breast up and out

Compress breast slowly until taut

Pull down on abdominal tissue to open inframammary fold

Instruct pt. to hold opposite breast laterally, out of anatomy of interest

Exposure on suspended respiration

Release compression immediately!

Breast Implants

Implants can be in front of pectoral muscle

or behind

Radiography Of Augmented Breast (implants)

Complications:Increased fibrous tissue surrounding implant (contracture)

Shrinkage HardeningLeakagePain!

Radiography Of Augmented Breast (implants)

8 projections must be obtained (2x4) (twice as many as non-implants)

Four images of breast including anterior breast and implant

Four images with implant displaced posteriorly into chest wall are obtained

Eklund Technique for Radiographyof the Augmented Breast

Treatment For Breast Cancer

Lumpectomy

Partial or radical mastectomy

Radiation

Chemotherapy

(recent study shows that lumpectomy or mastectomy may be no more beneficial than radiation and chemotherapy)

Lesion

Needle Localizations

Used to localize breast lesions before surgery

Special, open-hole plate may be used for ease of localization

Radiographic image of Lumpectomy

Imaging of lump after surgical excision

Breast Calcifications

Calcified Milk Ducts

Benign Cyst