Mammography

Mammography basics
Instrument
Views
Birads

1. MAMMOGRAPHY
DR. BRIBIN BRIGHT

2. MAMMOGRAPHY -INDICATIONS
Screening of asymptomatic women.
Screening of high risk women.
Follow up of patients after mastectomy of same and opposite breast / same breast with implant
Investigations of benign breast diseases with eczematous skin,nipple discharge , skin thickening .
Investigation of a breast lump.
Investigation of occult primary with secondaries .
Male breast evaluation .

3. TYPE OF MAMMOGRAPHIC EXAMINATION
Diagnostic mammography
Is performed on patients with symptoms or elevated risk factors.
Two or three viewsof each breast may be required.
Screening mammography
Is performed on asymptomatic women with the use of a two view protocol,
usually medial lateral oblique and cranio caudal , to detect on unsuspected cancer

4. MAMMOGRAPHY -BASICS
Uses low-energy x-rays (40kVp) for dectecting breast pathologies.
Higher kV -Poor Contrast
Lower kV -Good Contrast
Tissues within breast have verysmall difference inattenuation property-Lacks contrast
<40kVp -Good photoelectric effect-brings out contrast between the tissues within the breasts.
Better contrast
Better detailing of structures

5. INSTRUMENTATIONS
HIGH FREQUENCY X-RAYGENERATOR
X-RAY TUBE
ANODE
CATHODE
BEAM PORT
K-EDGE FILTERS
COMPRESSION PADDLE
SPOT COMPRESSION
PARALLEL LINEAR GRID
IMAGE RECEPTOR
AEC (AUTOMATIC EXPOSURE CONTROL)

6. X-RAY TUBE
Rotating Anodetype
-Glass orMetal ceramic
Advantage
-Decreases off focus radiation
-Increases Tube lighting
Cathode-Dual focalspots
0.3mm(Imaging)
0.1mm (Magnification)
(Focal spot-Penumbra-Resolution)
Helps identifiying microcalcification

7. ANODE (TARGET)
Usually-Tungsten (xray /Floro/ CT/ cathlab)
MOLYBDENUM -17.5 &19.6 keV
RHODIUM-20.2&22.7 keV
CHARACTERISTIC RADIATION
Characteristic x-ray Characteristic x-rays are produced after ionization of a k-shell electron. When an outer-shell
electron fills the vacancy in the k shell, an x-ray is emitted.
In mammography, 17.5-19.5kev characteristic x-ray is produced with Mo and 23kev is produced with Rh

9. ANODE ANGLE = 16°to0to -9°
EFFECTIVE ANODE ANGLE
-Angle of anode relative to the horizontal tube mount
XRAY TUBE TILT
-To reduceunwanted radiation
-focus only to the breast area

10. SOURCE TO IMAGE DISTANCE (SID)
-lesser than usual Radiography -60/65 cm(Chest = 18)
-short SID
-Heel Effect utilized
AtCathode→chestwall–Thicker tissues
SIDE
AtAnode→Nippleregion–Less Thickness
SIDE
Non-uniformityofX-ray Intensity
Along the cathode side -MoreIntensity
Along the Anode side-Less Intensity

11. PARTS OF MAMMOGRAPHY EQUIPMENT
Beam port-1 mm Beryllium
Since metal/ Glassisused in XRAY TUBE
metal will absorb the low energyphotonsfrom xray tube
K-edge filters-Cuts unwanted Lowenergy photons (RADIATION)
/High energy photons (SCATTER –Reduces contrast)
(0.03mm Mo / 0.025mm Rh)

12. PARTS OF MAMMOGRAPHY EQUIPMENT
To decreaseBreast thickness,spreadsout the tissue
-Spreads outsuperimposedanatomy.
Scatter Radiation- contrast
Radiation doseto the breast tissue
Geometric Blurring (closer to imagereceptor)
Decreases the kinetic blur .
Makes breast thickness uniformin film density.
Differentiatesthe easily compressible cysts and fibro-
glandular tissue from the more rigid carcinomas
Separatesthe super imposed breast lesions .
Compression paddle

13. PARTS OF MAMMOGRAPHY EQUIPMENT
GRIDS
Stationary grids or grids placed in between the screen and the film are no longer used as the thin grid lines
compromised on the quality of the image .
Covered tiny details such as microcalcifications
Hence oscillating grids are used o Grid ratio of 4 : 1 or 5 : 1
The grid lines are eliminated by the motionof the grid .
Grids improve the image quality and cause a significant reduction

14. PARTS OF MAMMOGRAPHY EQUIPMENT
Spot.compression -for imaging particular region
Parallel Linear grid-(4:1 to 5:1) low grade ratiogridsused
to increase theContrast
Image Receptor
Screen film
CR Cassette
Flat paneldetector -(Digital Mammography)
AEC-Automatic Exposure Control
KeV selected →MAS automatically chosen.

15. FLAT PANEL DETECTORS -INDIRECT
Indirect Amorphous silicon technology
Xray scintillator(Gradoliniun Sulphate / Csl)
Produceslightflashes when Xraybeam falls overit.
Silicon Photodiode array(Photo detector)
Made of Amorphous silicon
Converts light photonsfrom the scintillatorinto electrical signal
TFT-electronic switch
-Reads electrical signal
-Gives positional information
-This data is sent to AEC(Analogue toDigitalConverter)
AEC
Converts it into digital signaland are finally sent to Computerfor processing
Disadvantage-LIGHT SCATTER
Scattering oflight within the phosphors leading to unsharpness

16. FLAT PANEL DETECTORS -DIRECT
Crystals of amorphousselenium
directly converts Xrays intoelectricalsignal that is stored in a capacitor (ready to be read)

17. MAGNIFICATION TECHNIQUE
Toincreasethe visibility of finer details like microcalcification
Increase O ID -object to Image Distance
Breast is kept over a raised platform
No need for grid as there is presence of air gap

18. SCREEN FILM MAMMOGRAPHY
Old method
The image is created directly on a film-Non modifiable
Less sensitive for women with dense breasts
Screen film cassette used
Single emulsionfilm
Single screen
Terbium activated Gadoliniumoxysulphide
Screen emits green light
Film will be sensitive to greenlight(ORTHOCHROMATIC FILM)

19. COMPUTER RADIOGRAPHY (CR) MAMMOGRAPHY
A/K/A Filmless radiography
Electronic radiography
Digital storage phosphor imaging
Xray images are acquired in digital format
Photostimulable phosphor plates used
Imaging plate has high sensitivity to xrays
COMPONENTS
storage phosphor cassette
Storage phosphor reader
Bar code scanner
Workstation
Photostimuliable Phosphor (PSP) Cassette
PSPReceptormaterials
. BaFBr : Eu2+
. BaF (Br1): Eu2+
.Ba SrFBr: Eu 2+

20. DIGITAL MAMMOGRAPHY
Also called full-field digital mammography (FFDM)
-in which the x-ray film is replaced by electronics that convert x-rays into mammographic pictures of the breast.
Display Monitor-HIGH RESOLUTION (5 MP)
Direct Digital Mammography
-Flat panel detector with amorphous seleniumarray
Indirect Digital Mammography
-Flat panel scintillator with amorphoussilicon diode array

21. DIGITAL MAMMOGRAPHY
ADVANTAGE
Better contrast, more details.Better delineation of parenchyma & subcutaneous tissue
Better noise level reduction
Tolerance to over/under exposure (Avoids Repetition?
Post-processing techniques for better diagnosis
Radiation dose isdecreased-Mean glandular dosein mammography
Screen Film(2-3m bGy)
Digital (20-30% reduction)
Image can be seen quickly andstored digitally(less storage space )

22. LIMITATIONS OF 2D MAMMOGRAPHY
20%of cancers will be missed
10% recalled for additional workup
75-80% of biopsies result in benign lesions
sensitivity decreases with increased breast density
2D mammograms, take images only from the front and side, this may create images with
overlapping breast tissue

23. ADVANCES IN DIGITAL MAMMOGRAPHY
Computer-Aided Diagnosis
-usessoftware to detect area of clinicalsignificance andhighlightthemfor better output image
Digital Breast Tomosynthesis(DBT)
Xray Tube rotates /moves in a 50-55°arcaround the breast,
capturing several (11-25)low dose projections of the breast at different angles.
Then reconstructed to 3DProjection images (1 mm slices)
3D MAMMOGRAPHY

24. DIGITAL BREAST TOMOSYNTHESIS-DBT (3D MAMMOGRAPHY )
Disadvantages of DBT
•Twice the radiation compared to 2D mammo
•More storage requirements
•Takes longer time to read
•Cannot be read on demand
Advantages of DBT
•Increased cancer detection rate
•Lesions are better defined
•Precise location of lesions
•Less false positive recalls
3D MAMMOGRAPHY

25. HOW MAMMOGRAM IS PERFORMED ?

26. HOW MAMMOGRAM IS PERFORMED ?
CRANIO CAUDAL (CC VIEW)
demonstrate maximum tissue on both medial and lateral
aspects of the breast with the retromammary space and some
pectoral muscle
The following points were analyzed on CC view:
nipple should be in profile
nipple should point straight and should not be pointing lateral
or medial
PND (pectoral nipple distance) must be within 1 cm of the
same measurement of the MLO view.

27. HOW MAMMOGRAM IS PERFORMED ?
MEDIOLATERAL OBLIQUE(MLO VIEW)
demonstrate axilla, axillary tail, and inframammary
fold with all the breast tissue
The following points were analyzed on MLO view:
Breast should be pulled out with nipple in profile
The pectoralis muscle margin should be well visualized
The lower edge of pectoralis muscle should be at the level
of pectoralis–nipple line (PNL) or below
PND must be within 1 cm of the same measurement of
the MLO view.
When MLO image of both breasts are viewed as mirror
images, pectoralis muscle should meet in the midline and
form a “V”.

28. OTHER VIEWS
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

30. REPORTING A MAMMOGRAM
Breast Imaging Reporting and Data System (BI-RADS)
RISK ASSESSMENT AND QUALITY ASSURANCE TOOL developed by American college of radiology (ACR)
that provides a widely accepted lexicon and reporting schema for imaging of thebreast.
All mammographic, ultrasound and breast MRI findings and reports should closely adhere to the BI-RADS lexicon
and assessment categories.

33. THANK YOU