Mammography Full

1. Mammography

2. INTRODUCTION
 Breast imaging modalities available are Ultrasound, CT, Digital
Mammography ,MRI and scintimammography .
 Mammography remains the cornerstone of breast imaging .
 Only mammography when correctly performed and interpreted
offers the necessary reliability to diagnose the curable forms of
breast cancers.
 Ultrasound, MRI , CT are useful adjuncts once a lesion has been
detected by physical examination or by radiographic mammography.

6. INDICATIONS
 SCREENING
 Screening of asymptomatic women (40 to 44 baseline annual screening ,45 to 54 annually, 55 and
older every 2 years,
 Screening of high risk women
 Follow up of patients after mastectomy of same and opposite breast.
 DIAGNOSTIC
 C/O swelling, tenderness, mastalgia,
 Investigations of benign breast diseases with eczematous skin, nipple discharge , skin thickening .
 Investigation of a breast lump
 Investigation of occult primary with secondary's .
 Male breast evaluation .

7. POSITIONING TERMINOLOGY:
 Breast Axis:
 Saggital plane:
 Transverse plane:
Breast axis Axial plane
Attachment to chest wall
7

8. Contd…
Transverse plane
Breast is divided into 4
quadrants
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9. PATIENT PREPARATION:
 Explanation of procedure to the patient.
 The patient should be asked to change into hospital gown
 Should be instructed not to put on talcum powder/
/deodorant/antiperspirant/lotion under arms or on breasts on the
day of mammogram as can mimic calcium spots.
9

10. VIEWS
BASIC VIEWS:
A. Cranio-caudal view.
B. Medio-lateral oblique view.
SUPPLEMENTARY VIEWS:
A. 90 degree lateral (Medio-lateral/Latero-medial)
B. Axilla
C. Extended cranio-caudal (Lateral /Medial orientation)
D. Caudo-cranial / reverse cranio -caudal
E. Rotated cranio-caudal/ roll view
F. Oblique position / latero-medial projection
G. Cleavage view
H. Tangential
I. Spot compression
J. Magnification
10

11.  cc
 The casette is placed under the breast at the level of the
inframammary fold .
 The breast is then pulled until the inframammary fold is
taut .
 Compression applied
 Xray beam is directed vertically from above .
 Postero medial aspect included .
 MLO
 Best view to image all of the breast tissue and the
pectoral muscle .
 The C-arm of the mammographic unit is rotated to 45
degree so that the cassette is parallel to the pectoral
muscle .
 The film holder is kept high up in the axillary fossa and
the patients arm is abducted at the elbow by 80degrees.
 The x-ray beam enters the breast from the medial side –
compression is applied to the pectoralis major muscle .

13. Supplementary Views

14.  90° lateral
 Demonstrate exact location of a breast lesion
 If abnormality seen in MLO but not in CC to
demonstrate whether this is due to artifact or
superimposed tissue or it’s a true lesion
 Higher on lateral than MLO, then the lesion is in
the medial aspect
 Lower on lateral than MLO then the lesion is in
the lateral aspect
 Close to the same level on both views then the
lesions is in central aspects
 ML (mediolateral)
 for lesions located in the lateral breast
 LM (lateral medial)
 Demonstrates milk of calcium, owing to its
gravity dependency
 is best for evaluating medial lesions

15. Exaggerated craniocaudal
 Exaggerated craniocaudal (XCCL)
 Show lesions in outer quadrant, axillary tail and
axilla, not seen on CC view
 Extended CC /medial orientation (XXCM)
 Demonstrating lesions in the medial portion of the
breast
 The maximum inclusion of the medio-posterior part
of the breast is demonstrated.
(XXCL)

16.  Roll view
 Used to separate superimposed breast
tissue, with either lateral or medial
orientation.
 Two exposure are often required with
breast rolled in RL – counter
clockwise ,RM- clockwise of R breast
 RM (rolled medial)
 Verify true lesions
 RL (rolled lateral)
 Determine location of lesion seen in
one view by seeing how location
changes

17.  Tangential (TAN)
 Verify skin lesions, to locate skin
calcification or lesions considered to be
near skin
 for palpable lesions that are obscured
by surrounding dense glandular tissue
on mammogram.
 Cleavage view
 Show lesions deep in posteromedial
breast not seen in CC view
 To view postero-medial portion of both
breasts

18.  Axillary view
 also known as a "Cleopatra view”
 Valuable in women where lymph gland
involvement of a breast carcinoma is
suspected or there is accessory breast tissue.
 Demonstrate of entire axillary tail (separation
of parenchyma from thoracic wall indicates
that all of axillary has been shown).
 Lateromedial oblique (LMO)
 Improved visualization of superomedial tissue
 Improved tissue visualization and comfort for
women with pectus excavatum, recent
sternotomy, prominent pacemaker

19.  Caudo-cranial /Reverse cranio-caudal
 Reverse CC may be helpful when Pt is small , or a muscular
male.
 Improved resolution is needed for the suspicious area in
superior or the upper quadrant of breast.
 Patient is dyphotic, has a pacemaker.
 Needle localization is performed on an inferior lesion.

20.  Spot compression
 Determine whether lesion is real or is a
summation shadow
 Spot compression with magnification (M)
 Better definition of margins of masses
and morphology of calcifications
 to evaluate and count micro-calcifications
and its extension
 requires magnification platform to
separate the compressed breast from the
cassette
 1.5 to 2 time magnification
 obtained by increasing the object-film
distance, producing an `air gap',

21. Imaging is similar to that of a small female breast.

22. GALACTOGRAPHY (DUCTOGRAPHY)
 Also called contrast mammography ductography as the study
includes the injection of contrast material into a duct.
 There is 10% incidence of carcinoma in women operated upon for
nipple discharge.
 It is done for evaluation of spontaneous nipple discharge that is
bloody, serous or clear in nature originating from one or two ducts.
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23. PROCEDURE
 Clean the nipple with cleansing agent & betadine is applied.
 Needle is inserted under aseptic conditions into the orifice of
discharging duct.
 C/M is injected about 1-3 ml.
 Immediate radiographs are taken in cranio - caudal and medio -
lateral oblique positions.
 Heavy compression is not applied because c/m will ooze out due to
pressure. So light compression is given.
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24. Pathology findings

25. Mass
 A 'Mass' is a space occupying 3D lesion seen in two different
projections.
 If a potential mass is seen in only a single projection it should be
called a 'asymmetry' until its three-dimensionality is confirmed.

27. Calcifications
 Calcifications are either typically benign or of suspicious morphology.

30.  BI-RADS assessment categories can be summarized as follows :
 Category 0 - Need additional imaging evaluation
 Category 1 - Negative
 Category 2 - Benign finding, noncancerous
 Category 3 - Probably benign finding, short-interval follow-up suggested
 Category 4 - Suspicious abnormality, biopsy considered
 Category 5 - Highly suggestive of malignancy, appropriate action needed
 Category 6 - Known cancer, appropriate action should be taken

31. Principles Of Breast Cancer
 Patients in the early stages respond well to extensive surgery
 Patients with advanced disease do poorly
 The earlier the diagnosis, the better the chance of survival
 Mammography is the tool for early detection
 Incidence increases with age
 More sensitive to carcinogens during menarche
 Women with positive family members are more prone to breast
cancer

32. MQSA
 Mammography Quality Standards Act
 Mandated the following:
 Formal training and continuing education
 Required regular inspection of equipment
 Documentation of quality assurance
 Report means of reporting results, follow-up, tracking patients,
and monitoring outcomes

33. Typical Mammography Unit

34. MAMMOGRAPHY EQUIPMENT
 designed to image the soft tissue of the breast while displaying the
necessary subtle contrast differences.
 High frequency generators
 Cathode – dual filament in focusing cup with focal spot size 0.3-0.4 and
0.1-0.15 mm (for magnification)
 Anode - rotating ,SID – 65cm
 low operating voltage - below 40 kV,
 Target – (Mo), (Rh) (W)
 Beryllium window – Minimizes absorption of radiation within the tube .
 Filter – Mo/Mo, Mo/Rh , Rh/Rh , W/Rh , W/Ag
 Compression device : 1-4 mm thick plastic plate

35. Anode design
 rotating anode
 Characteristics X-ray production is the major reason for choosing Mo (K-shell
x-ray energies of 17.5 and 19.6 keV) and Rh (20.2 and 22.7 keV) as targets.
 With tungsten targets, Bremsstrahlung x-rays will predominate at energies
above and below the 17-24 keV range. Although tungsten emits “harder”
spectrum rays, the wider dynamic range can be utilized in digital imaging.
 requires the effective anode angle to be at least 20º to avoid field cutoff for the
24 x 30 cm field area
 Combination of anode angle and tube tilt used

37. Compression Device
 manual, hand-controlled compression device, controlled by the
mammographer.
 The effects of compression are: reduced dose; reduced scatter-
improved contrast; less geometric unsharpness; low movement
unsharpness; uniform breast thickness; reduced tissue overlap
improved resolution.
 Amount of compression – 25- 45 lbs pounds of pressure (111-200N)
 may be uncomfortable for the patient

38. Compression Device

39. GRID
 Grid is used to reduce the scatter radiation reaching to the film
 Most system have moving grid with a ratio of 4:1 to 5:1 .
 Grid frequency» 40 lines/cm.
 Specially HTC grid is used in mammography.
 cellular grid, made of thin copper septa, provides scatter rejection in
two dimensions . Specifications of this design include a septal height
of 2.4 mm, 0.64-mm distance between septa (3.8 ratio), a septal
thickness of 0.03 mm, and 15 cells/cm

41. Heel effect
 Lower x-ray intensity on the anode side of the field at short SID
 Positioning the cathode over the chest wall of the patient and the
anode over the nipple achieves better uniformity of the radiation
transmitted through the breast
 Orientation of the tube in this fashion also decreases the equipment
bulk near the patient’s head for easier positioning

43. Focal spot considerations
 Focal spot sizes range from 0.3 to 0.4 mm for non magnification
 and from 0.1 to 0.15 mm for magnification imaging
 Focal spot and central axis are positioned over the chest wall at the
image receptor edge
 A reference axis, which typically bisects the field, is used to specify
the projected focal spot size

45. Beam quality considerations
 The optimal x-ray energy to achieve high subject contrast and the lowest radiation
dose would be a monoenergetic beam of 15 to 25 keV, depending on breast
composition and thickness
 Screen-film detectors most often use a Mo target and 0.03-mm Mo filtration with a
kV of 24 to 25 kV for thin, fatty breasts and up to 30 kV for thick, glandular breasts.
 For thicker and denser breasts, a Mo target and Rh filter are selected with higher
voltage, from 28 to 32 kV, to achieve a higher effective energy and more penetrating
beam
 We need relatively low penetration to enhance contrast but high penetration is needed
to reduce the dose to the breast.
 The solution is to use an x-ray beam that has a spectrum that produces an optimum
balance between the requirements for high contrast sensitivity and low radiation
dose.

46. Beam Filtration
 Filtration is defined by the half-value layer (HVL).
 In mammography added filtration shapes the emission spectrums of the x-ray beam
and makes it compatible with the image receptor and breast characteristics of each
patient.
 Filtration will also improve the energy-distribution x-ray spectrum by selectively
removing the very low energies and higher energies outside of the desired range.
 In digital imaging, filtration will also help to reduce exposure time, eliminating
potential motion artifacts.
 Minimum HVL is specified by regulations and should not measure less than 0.30 mm
Al at 30 kVp or 0.25 mm at 25 kVp to ensure that the patient will not receive
excessive radiation dose.
 The HVL also should not exceed 0.40 mm Al at 30 kVp to avoid excessive filtration
that would reduce contrast by filtering out the low-energy photons necessary to
penetrate the breast tissue.
 Any HVL assessment must include an assessment of both the inherent and added
filtration.

47. Filtration
 Inherent filter- require beryllium (Z = 4) to permit the transmission
of low energy x-rays.
 Added filter - thin filters of Mo, Rh, and silver (Ag) used to transmit
bremsstrahlung x-rays in the intermediate energy range (15 to 25
keV), including characteristic radiation from Mo and Rh, and also to
highly attenuate lowest and highest x-ray energies in the spectrum
 The filters used in mammography are based on the "k edge"
principle and attenuate or block the radiation above the k-edge
energy of the specific filter material

53. Collimation
 For most mammography examinations, the field size matches the
film cassette sizes (e.g., 18 x 24 cm or 24 x 30 cm)
 Variable shutters on some systems allow the x-ray field to be more
closely matched to the breast volume
 In practice, the large unexposed area of the film from the tight
collimation allows a large fraction of light transmission adjacent to
the breast anatomy on a light box, and can result in poor viewing
conditions
 X ray beam is collimated by means of cone which produces D-
shaped field.

54. Generator & phototimer(AEC)
 High-frequency generators are the standard for mammography systems
 Unlike most conventional x-ray units, the AEC detector is located
underneath the cassette
 Phototimer algorithms take into account the radiographic technique (kVp,
target/filter) and, in the case of extended exposure times, reciprocity law
failure, to achieve the desired film optical density
 Fully automatic AEC sets the optimal kV and filtration from a short
test exposure of ~100 msec
 TWO TYPES :
 (i)Ionization chamber type
 (ii) Solid state diode type

56. Screen-Film Systems
 Mammography cassettes contain a single screen
 The film is single emulsion
 Occasionally, extended time processing is used
 This reduces dose and increases contrast

57. Screen-Film cassettes used in
Mammography

58. Magnification
 referred to as macro radiography
 Mammo only modality that routinely uses magnification views
 Use a raised platform to support the breast about half way between
focus and film i.e. not in close(ish) contact anymore
 Magnification is the result of the diverging X-ray beams travelling in
straight lines

59. Magnification imaging
 Magnifies image by a factor of
between 1.5-1.8
 Magnification increases geometric
unsharpness so small focal spot is used
 Increases exposure times due to
lower mA
 Can remove grid to lower exposure
factors (and patient dose) as scatter is
reduced by the air gap
 Overall patient dose is higher
 Magnification requires individual
justification

60. Digital Mammography
CCD
camera

61. Physics of full field digital
mammography
(FFDM)

62. FFDM Differences
 Image acquisition and display are separated
 Wide dynamic range
 Lower Dose (~20%)
Same dose limits as for film-screen
 Higher kVp (+3 kVp)
 Better for dense breasts
 Imaging detector can be used as AEC detector
 Use of Mo/Mo, Mo/Rh, Rh/Rh, W/Rh and W/Ag targets
 For CR, the film-screen cassette is replaced with a
photostimulable phosphor plate cassette

63. FFDM Differences
 Digital images
Require workstations
Post-processing image enhancement
Computer aided diagnosis
Archival issues (>9 Mbyte/image)

64. AEC is different
 Done with the image detector rather than discrete radiation
detectors.
 System can automatically select the densest aspect of the breast
for AEC “cell” positioning or the technologist can manually
select the AEC “cell” position

65. Digital mammography detectors
 X-ray to digital information.
 “DIRECT” conversion - Amorphous selenium (direct conversion)
using (TFT) flat panel technology ~70 micron pixels
 “INDIRECT” conversion - Scintillating phosphor (CsI columns)
on an array of amorphous silicon photodiodes using thin-film
transistor (TFT) flat panel technology ~100 micron pixels

66. Independent (“Indirect”) Conversion:
Blocking
Layer
CsI
X-Ray Photons
Light
Photodiode Photodiode
Electrons
Read Out Electronics
X-ray
Digital
Data
2,600+
Volts
Electrode
Dielectric
Digital
Data
Electrons
X-Ray Photons
Selenium
K-edge
Fluoresence
Electrons
Read Out Electronics
X-ray
Electrode
Capacitor
Dependent (“Direct”) Conversion:
Detector Technology Overview
Courtesy: Jill Spear, GE Women’s Healthcare

67. Does pixel size matter?
 As pixel size decreases:
Spatial resolution improves
Noise increase
Signal-to-noise decreases

68. Computed Radiography for
Digital mammography

69. Digital Mammography
 Detector is a flexible plastic coated with photostimulable x-ray
absorbing phosphor material.
 The electronic charges are stored in “traps” in the material of
phosphor.
 The image is then read by scanning of imaging plate by a laser
beam.
 The resulting signal is logarithmically amplified,digitized and
processed for film or soft copy display.
 The imaging plate is erased by exposure to white light.

70. Mean glandular dose
 The mean glandular dose (MGD) is an estimate of the average absorbed dose to the
glandular tissues of a breast during mammography. It is measured in Gray (Gy).
 MGD = Kgds
 K = entrant surface air kerma
 g = conversion factor for 50% glandular breast based on thickness and half-value layer
 c = correction factor based on non-standard glandularity/thickness
 s = correction factor based on non-molybdenum anode/filter combination
 standard breast (defined as 4.2 cm thick when compressed, with a 50:50 ratio of
glandular tissue to fat), the MGD is typically 2 mGy per view.
 For full-field digital mammography systems, the dose is lower, typically from 1.2 to
1.8 mGy per view.

71. Recent advancements and
modalities

72. Contrast Enhanced Digital Mammography
 CEDM is a recent development of digital mammography using the
intra-venous injection of an iodinated contrast agent in conjunction
with a mammography examination.
 is being used sparsely for cancer staging or neoadjuvant follow-up in
places where MRI may not be available.
 This technique can increase mammographic lesion conspicuity.

73.  Two techniques have been developed to perform CEDM examinations –
 1. Temporal Subtraction :
 Done by acquisition of high-energy images before and after contrast medium
injection.
 The temporal subtraction technique offers the possibility to analyze the
kinetic curve of enhancement of breast lesions.
 Dual-energy takes advantage of the difference in the atomic density of
tissue, as compared to the contrast. Two images are acquired, and the low-
density breast tissue is subtracted; however, the high energy of contrast
persists, allowing any enhancing abnormality to be more visible.
 The main disadvantages of this technique are that only a single breast can be
imaged and patients have to maintain a particular position (usually MLO) for
a prolonged period
 Prone to Motion artifacts

74.  2. Dual Energy CEDM
 technique based on dual-energy acquisitions, where two images are acquired using
distinct low-energy (standard mammography kV and filtration) and high-energy (higher
kV with strong filtration) X-ray spectra.
 The differences between X-ray attenuation of iodine and breast tissues at these two energy
levels are exploited to suppress the background breast tissue.
 Dual-energy CEDM depicts areas in the breast associated with increased vascularity 2
min after the start of contrast injection that images are acquired.

75. Post-contrast images show an enhancing
lesion infero-medial quadrant - DCC
Post contrast images show an enhancing
lesion proved to be malignant on biopsy

77. Breast Tomosynthesis
 Also known as 3D mammography.
 Its an extension of digital mammography
 Breast tomosynthesis is a new tool that is based on the acquisition of three-
dimensional digital image data, could help solve the problem of interpreting
mammographic features produced by tissue overlap.
 In breast tomosynthesis, a moving x-ray source and a digital detector are used.

78.  The x-ray tube in a breast tomosynthesis system moves along an arc
during exposure.
 An arc like linear motion is suitable for imaging of breast tissue because
most normal anatomic structures in the breast are oriented from the
chest wall to the nipple.
 A wider angular range allows a thinner reconstructed section thickness
of the in-focus plane because objects in the different planes are less
blurred on images acquired at a smaller angle.

79. Normal glandular tissues are more clearly depicted on the
breast tomosynthesis image (arrows in a) than on the digital
mammogram (b).
Normal lactiferous ducts are more prominently depicted on
the breast tomosynthesis image (arrows in a) than on the
digital mammogram (b).

80.  Advantages
 it has the same advantages as that of FFDM.
 Better depiction of the smallest calcifications, better delineation of the lesion border
 requires less compression than 2D mammography.
 Disadvantages
 Motion artifacts are more likely to occur
 Large calcifications cause significant artifacts.

81. Computerized Tomography Laser
Mammography
 Is an optical tomographic technique for breast imaging.
 uses laser energy in the near infrared region of the spectrum, to detect angiogenesis in the
breast tissue
 It is optical molecular imaging for hemoglobin both oxygenated and deoxygenated.
 laser beams travel through tissue and suffer attenuation then a laser detector measures the
intensity drop and the data is collected as the laser detector moves across the breast
creating a tomography image.
 is able to recognize malignant tumor from benign lesion
 And shows hemoglobin distribution in a tissue , detect areas of Angiogenesis

83. Scintimammography
 Scintimammography, also known as nuclear medicine breast imaging, (Breast
Specific Gamma Imaging (BSGI) or Molecular Breast Imaging (MBI).
 Done in those who had abnormal mammograms, or for those who have dense breast
tissue, postoperative scar tissue or breast implants.
 Patient receives an injection of a small amount of a radioactive substance called
technetium 99 sestamibi, which is taken up by cancer cells, and a gamma camera is
used to take pictures of the breasts.
 The procedure is less accurate in evaluating abnormalities smaller than one
centimeter.
 Patient is exposed to slightly more radiation than mammography but has higher
sensitivity and positive predictive value than conventional mammography.

84. Optical Mammography
 Diffuse optical imaging is a set of non-invasive imaging modalities that use near-
infrared light then applies an algorithm to interpret the image and information. The
technique can measure differences in water and fats.
 The tool creates real-time images of metabolic changes, allowing the differentiation
between oxygen rich and oxygen-poor tissue and varying levels of hemoglobin
through differences in light absorption.
 comparatively more comfortable with much less breast compression compared to
conventional mammography.

86. Computer Aided Detection
 Mammography has a low positive predictive value of 35% in detection of
malignancies.
 But, due to the high number of mammograms to be read, the accuracy rate tends to
decrease
 CAD can assist the medical staff to achieve high efficiency and effectiveness, thereby
reducing the false positive rate.
 It is a two level reporting system thus helps to reduce interpretative or subjective
errors.
 studies have shown the ability of CAD to mark cancers with a high degree of accuracy,
especially when microcalcifications are present

88. Positron Emission Mammography
 PEM has higher resolution and a more localized field of view ,performed on patients
to stage a newly diagnosed malignancy.
 uses a pair of dedicated gamma radiation detectors placed above and below the breast
and mild breast compression to detect coincident gamma rays after administration of
fluorine-18 fluorodeoxyglucose (18F-FDG)
 cancer cells demonstrate increased utilization of glucose. Through use of isotope
fluorine-18 attached to the delivery compound deoxyglucose to produce the
radiopharmaceutical 18F-FDG, this utilization of glucose can be visualized.
 Advantages such as better delineation of lesion, high positive predictive value for
malignancies and effective in follow up or in planning for RT
 Has higher radiation exposure

89. Breast Ultrasound
 Breast ultrasound is an important modality in breast imaging.
 Use of breast ultrasound:
• evaluate young (usually under 30 years of age) or pregnant patients who are symptomatic
• evaluate a palpable lump with negative or equivocal mammographic findings
• detect lesions in lower contrast field
• help to distinguish between benign vs malignant characteristics
• guiding biopsy
• evaluate breast implants for rupture
 reasonable sensitivity but poor specificity
 may have a place in screening women at high risk or with mammographically-dense breasts
 probe: linear array 7-13 MHz

90. Breast MRI
 It is a valuable tool to diagnose additional cancer in the same breast in up to one
third of patients and is recommended as a supplemental screening tool to
mammography in women considered to be at high risk for developing breast
cancer.
 MRI is more sensitive in detection of invasive lobular cancer,
 Dedicated bilateral breast surface coil (simultaneous examination of both breasts)
 Preoperative MRI more accurate in assessing tumor extent and multi-focality
(incl. DCIS)
 MRI lowest FN rate in detecting Invasive lobular carcinoma, highest accuracy in
measuring the size
 MRM could detect extensive intraductal component (EIC): sensitivity 71%,
specificity 85%, accuracy 76%

91.  Pitfalls
 MRI typically costs more and takes more time to perform than other
imaging modalities.
 MRI persistently underestimate minimal residual disease

92. Electrical Impedance Scanning (EIS)
 used as an adjunct tool to mammography in helping to detect breast cancer.
 The T-scan measures low level bioelectric currents to produce real-time images of the
electrical impedance properties of the breast. The resulting impedance images of the breast
tissue can be used to help determine if the region of interest is normal tissue or a cancerous
tumor.
 The T-scan works by creating an image "map" of the breast using a small electrical
current.
 One-volt of continuous electricity (approximately the same as holding a flashlight battery
by its ends) is transmitted into the body, either through an electrode patch attached to the
arm or a hand-held cylinder.
 The electric current travels through the breast where it is then measured at skin level by a
probe placed on the breast.

93. Mammographic equipment specification
 Company- Siemens healthcare
 Model –Simens mammomat fusion full field digital mammography
 X-ray tube – tungsten rotating anode tube with beryllium window P40
 Anode speed – 8800rpm
 C-arm rotation:180 degree to -180 degree
 Power rating – 5kw
 Anode heat storage capacity – 162KHU
 Inherent filtration: 1mm Be (- 0.02 mm Al)
 Focus size – 0.3 , 0.15
 Detector type – CSI
 Detector size – 23* 30 cm
 Anode material – W , Filter – 50 micro m Rh

94.  Grid ratio – 5:1 , linear grid
 Grid density – 31 lines/cm
 Kv range – 25kv – 35kv (adjustable in 1 kv increments)
 mAs – 5mAs to 600mAs AEC mode
 Time range – 10ms-4s with large focus, 60ms to 6s with small focus
 mA range – 20 to 190 mA
 Collimation – automatic
 Magnification compression plate – 16*20cm
 Spot compression plate – 9*9cm
 SID – 65cm
 Weight – max 350kg

95. REFERENCES
 The essential physics of medical imaging by Bushberg
 Radiologic science for technologist by Bushong
 Chesney’s equipment for student radiographer
 Websites