mammography

It's all about mammography unit

1. mammography?

2. first used to examine breast tissues by the german surgeon- ALBERT SALMON . a mammogram is a x ray exam of breast to detect and evaluate any changes in the breast.

3. indication b reast cancer-the first symptoms of breast cancer usually appear as an area of thickened tissue in the breast. other symptom-pain, resdness, nipple discharge, inverted nipple, change in the size o shape of the breast. stages of breast cancer- *stage 0= known as ductal carinoma in situ, (cells that line the milk ducts of the breast have become cancer). *stage 1= tumors measures upto 2 c.m across. it has not affected any lymph nodes. * stage 2 = it has started to spread to nearby nodes , has not spread to the lymph nodes. *stage 3 = the cancer has spread to distant organs.

4. breast lump: localized swelling. nipple discharge. breast pain. follow up for previously evaluated mammographic findings.

5. contra-indication pregnancy radiation therapy to chest / mediastinal active collagen disease : immune system causes inflammation in our collagen, it is the main structural protein found in various connective tissue.

6. mammography x - r a y tube target materials consists of- molybdenum (42) rhodium (45) molybdenium is the best material to be used in mammography. allows production of low energy spectrum of radiation low kvp(26-40)

7. filtration materails that are placed in the path of the x ray beam in order to absorb those x ray with low energy. molybdenum- best used for lower kvp rhodium yttrium (39)

8. collimation: used to shape radiation field. less scatter. smaller exposed area, better for patient dose.

9. breast compression breast is compressed using a rigid transparent plastic compression plate. breast is compressed for better spatial resolution . spatial resolution is the ability of an imaging system to diffrentiate between two near by objects. reduce movement blur.

10. views : standard view:craniocaudal view(cc view), 45 degree lateral oblique(MLO). additional view: extendd CC view,true lateral view, axillary view, cleavage view, paddle compression view, magnification view, eklund view.

11. what is CC View? the mammography equipement is positioned with the x ray beam axis pointing vertically downwards. the women faces the machine, with her arms by her side. she is standing and is rotated 15-20 degrees to bring the side under examination close to the horizontal breast -support table. the table is at the level of infra mammary crease(lower boundary of breast)

12. the nipple should be in the midline of the breast and in profile. the women head is turned away from the side under the examination. the breast is lifted up and rotated medially 5-10 degrees so that the nipple is just medial to the midline of the film. as the hand is removed, the breast is compressed firmly to a level that the women can tolerate. a remote cotrolled foot compression device allows this to be achieved more easily. compression must be released as soon as the exposure ends.

13. MLO allows visualization of the largest amount of breast tissue. the mammographic equipement is routinely angled at 45 degrees from the vertical. the women arm is placed on the top of the table with elbow flexed and dropped behind it. the table height is adjusted so that the lower border of the breast is 2-3 c.m above the edge of the film. the breast is gently extended upwards and outwards to ensure it contacts the breast - support table. the compression plate is applied. when the compression is almost complete, the breast is checked for skin folds and radiographer’s hand is removed.

14. 45 degree lateral oblique(MLO). lateral side of the breast is probably the most common place for pathological changes to occur. for an ML view, the tube emitting the x-ray is medial and the detector plate is lateral . for the LM view, the tube is lateral and the detector is placed medially. lateral views are extremely useful in determining the exact location of an abnormality in the breast. ML view is best for lesions located in the central or lateral breast LM view is best for evaluating medial lesions.

15. extended cranio-caudal view: the routine CC view will not showmany abnormilities in the upper quadrant of the breast, which will be demonstrated on the medio-lateral oblique projection. as all lesions must be demonstrated on two projections, this extended crnio-caudal projection is useful for demonstrating the outer quadrant, axillary tail and axilla. the women stands close to the equipement, with her breast aligned slightly side of the midline of the breast support table. the breast is lifted gently and placed on the table

16. the women is then encourged to lean 10-15degrees laterally. compression is applied , the exposure is made and compression released immediately.

17. magnification view A magnification view in mammography is performed to evaluate and count microcalcifications . This allows the acquisition of magnified images of the region of interest. magnified projections are done in the cranio-caudal and mediolateral projections. the women is placed in the position for the lateral and cranio caudal projections in turn. it is important to realize that the field will cover only the half of the breast under examination. Provides additional information on margins, satellite lesions, and microcalcifications. Can also be useful for asymmetric tissue .

18. cleavage view A cleavage view (also called "valley view") is a mammogram view that depict the posteromedial portion of both breasts (the “valley” between the two breasts) by placing them on the cassette at the same time and pulling them anteriorly. Modified CC view that improves visualization of area between breasts. Both breasts are positioned on the detector.

19. axillary view An axillary view (also known as a "Cleopatra view“) is a type of supplementary mammographic view. It is an craniocaudal view for better imaging of the lateral portion of the breast to the axillary tail. This view allows imaging of the axillary tail of the breast. It resembles the ML view but allows evaluation of breast tissue more laterally oriented.

20. spot view A spot view (also known as a spot compression view or focal compression view) is an additional mammographic view performed by applying the compression to a smaller area of tissue using a small compression paddle, increasing the effective pressure on that spot. This results in better tissue separation and allows better visualization of the breast tissue in that area.

21. patient preparation? give verbal instruction. patient should refrain from using lotions, powder, and deodrants the day of examination. patients clothing from waist up will be removed.

22. abnormalities: cysts: f l uid filled sacs. calcification: deposition of calcium. fibroadenomas: benign tumors.

23. Why is compression important in mammography? Decreases radiation dose Separates glandular tissue Decreases superimposition of tissue Improves resolution or clarity of the image Increases contrast to visualize subtle differences in tissue Reduces scatter radiation

24. digital mammography Digital mammography is a specialized form of mammography that uses digital receptors and computers instead of x-ray film . the X-ray film is replaced by solid-state detectors that convert X-rays into electrical signals. The electrical signals are used to produce images of the breast that can be seen on a computer screen or printed on special film similar to conventional mammograms. also called full-field digital mammography (FFDM)

25. Tomosynthesis (3D Mammography) Tomosynthesis or “3D” mammography is a new type of digital x-ray mammogram which creates 2D and 3D-like pictures of the breasts. This tool improves the ability of mammography to detect early breast cancers . The images include thin one millimeter slices. The “3D” images reduce the overlap of breast tissue, and make it possible for a radiologist to better see through your breast tissue on the mammogram.

26. Multiple studies have shown that “3D” mammography increases the detection of breast cancer by approximately 25%, and decreases the number of false positive call backs by approximately 15%.

27. Galactography or ductography is a medical diagnostic procedure for viewing the milk ducts. The procedure involves the radiography of the ducts after injection of a radiopaque substance into the duct system. The procedure is used for investigating the pathology of nipple discharge.

28. ADVANTAGES It is time-efficient. It is easier to see slight differences between tissues. It requires lower average radiation dosage. Reduces the risk of dying from breast cancer . Reduces the risk of having to undergo chemotherapy .

29. LIMITATION they are no 100% accurate in showing if a women has breast cancer. mammograms look normal though breast cancer is present. mammograms look abnormal een though there is no cancer in breast. women with dense breasts have more false negative limitations of mammograms.

30. Xeroradiography /xeromammography X-ray imaging in which a picture of the body is recorded on paper rather than on film. a plate of selenium, which rests on a thin layer of aluminium oxide . Xeromammography is a photoelectric method(electrically charge particle is released within a materia; when it absorbs electromagnetic radiation) of recording an x-ray image on a coated metal plate, using low-energy photon beams, long exposure time, and dry chemical developers. This process was developed in the late 1960s by Jerry Hedstrom, and used to image soft tissue, and later focused on using the process to detect breast cancer.

31. Xeroradiography /xeromammography photoelectric method. records images without film. latent image is converted to positive image .

32. xeroradiography Vs Radiography elimination of accidental film exposure, economic benefit, reduced exposure to radiation dose. it involves neither we chemical processing nor the use of the dark room. dis:the process of developement cannot be layed and is it to completed within 15mins.

33. components: xerographic plate. corotron. casette. toner. special paper.

34. xerographic plate. sheet of aluminium in which a layer of amorphus selenium has been deposited. In addition, there is an interface layer between the selenium and aluminium and an overcoating protecting the selenium surface. layers: overcoating, selenium, interface, aluminium.

35. procedure the first step in xeroradiographic process is to sensitise the selenium the selenium layer by applying a uniform electrostatic(biuld up charges due to conatct with other crges) charge to its surface in the dark .

36. principle: the XR plate is charged to a high positive potential by corotron(charging device) it is then placed in a cassette and used in a manner similar to that with conventional film in its casette. when x rays strike the selenium, photoconduction(material become more electrically conductive due to absorption of x rays) occurs and this produces a charge image of the part examined. the image is made visible by bringing into proximity to the plate charged developer or toner particles. the resultant powder image is subsequently transferred to paper and fused providing an opaque XR interpretation and storage.

37. process: plate is sensitizes before the exposure. the charged plate is placed in a light tight casette and is exposed to x rays. the x ray reaching the plate cause the photoconductor layer to lose its charge in an amount corresponding to the intensity of x-ray beam. the uniform charge is thus dissipated and the remainning charge patterns form the ltent electrostatic image.

38. the exposed plate is placed on the top of a dark box into which an aerosol of charged tonner particles is sprayed through a nozzle(produces millions of ink droplets used in creating the image) all toner must be removed before the plate is to be reused. the plate is exposed to a light source that reduces the bond holding the residual toner to the plate. a preclean corotron exposes the plate to an altrnating current .

39. image quality image quality is based on --- radiographic mottle sharpness resolution. radiographic mottle- depends on film screen mottle and film gradiness. screen mottle depends on structure mottle and quantum mottle.

40. radiographic mottle: it is also known as noise. it directly related to the number of x-ray photons. Fewer photons reaching the image receptor will cause an undesirable fluctuation in image densities, resulting in images with a grainy, or sandlike, appearance.

41. sharpness ability to define edge of film. types of unsharpness: geometric unsharpness, motion unsharpness and photographic or system unsharpness. geometric unsharpness: *Two principal factors play simultaneously: the apparent focal spot size and the ratio between object-film distance (OFD) and focus-film distance (FFD). *Fine focal spot sizes will minimise geometric unsharpness, and therefore give more detailed images.

42. sharpness * Keeping the ratio FFD:OFD high will minimise geometric unsharpness. Motion unsharpness : *is caused by movement of the patient, the detector or the source of X-rays during the exposure. *Movement of the patient can be minimised in a number of ways: immobilizing the patient, asking the patient to keep still or to hold the breath and keeping exposure time short.

43. photographic unsharpnesss : *result of the detector system employed.

44. resolution Resolution is the ability of an imaging system to display two adjacent objects as discrete entities. Resolution is also known as spatial resolution