Basic Projections

• Mammography: Basic Projections

  • Importance of clinical background
  • Issues of consent and exposure justifications
  • Communication and the development of a rapport with the patient
  • Points of technique relating to all examinations, including anatomical positioning – "the whole-body technique"
  • Compression of the breast – why & how
  • Anatomically derived mammographic principles
• Reasons women attend a mammography unit

  • National or Local Screening Programs
  • Family history surveillance
  • Breast symptoms
  • Additional views
  • Stereotactic-guided needle biopsy & marker localization
  • Screening research studies
  • Follow-up mammography
• Screening Mammograms

  • No symptoms or signs of breast cancer
  • Average risk for breast cancer
  • Reduces breast ca mortality in 50-70 age group
• Diagnostic Mammograms


  • Women with symptoms such as a lump, pain, nipple thickening or discharge
  • Changes in breast shape or size
  • Used to evaluate abnormalities detected in screening mammogram
• Justifying the exposure


  If a request goes outside the normal protocols & the patients may be at risk from unnecessary radiation, RT should not proceed until the situation is clarified and the request is justified
• Informed or Valid Consent


  • They need to know that the screening test is not 100% effective and that a recall for further tests is a possibility, before proceeding with the examination
  • Withdraws consent at some point during the procedure
  • Those who are brought by relatives and professional care staff can be assisted to understand the process with the use of appropriate guidance; in form of images, sign language and demonstration
• Pre-mammography discussion

  • Establishing Rapport
  • Explaining the Procedure
  • Relevant History
  • Observing and Reporting Clinical Signs
• Film Marking


  To assist in orientation, annotations should always be placed on the lateral/axillary edge and at the corner of the film away from the patient
• Anatomical Positioning


  • Mammography is a whole-body technique
  • Correct positioning of feet, arms & spine are crucial in producing high-quality diagnostic mammograms
  • The patient can be position standing or seated
• Manipulating & Controlling the Breast


  • The breast should be held firmly, the hand cupping the breast with the thumb & fingers at the posterior margin of the breast against the chest wall; the internal structures of the breast must be grasped, not just the overlying fat
  • Handling the breasts in this manner will maintain control of the breast throughout the procedure and ensure the patient has confidence in the radiographer
• Compression of the Breast


  • Compression of the breast tissue is essential for good mammography
  • One hand controls the position of the whole body while the other manipulates the breast
  • Standard teaching "not moderate compression but the most vigorous possible compression tolerated by the patient"
  • Much of the resultant pain originated from compression of the axillary muscles & overlying soft tissues
  • In UK, maximum force permitted to be applied to the breast is 200 Newtons
• Beneficial Effects of Breast Compression During Mammography


  • Reduction of Internal X-Ray Beam Scatter
  • Improved Contrast
  • Spreading of Breast Tissues: Reduced Superimposition, Clearer Demonstration
  • Reduced Geometric Unsharpness
  • Reduced Movement Unsharpness
  • Reduced Radiation Dose to the Breast
  • More Homogenous Film Density
• Range of Force (Newtons) Applied to the Breast During the Production of Good-Quality Mammography

  • Craniocaudal (CC): 70 – 140
  • Mediolateral Oblique (MLO): 100 – 140
  • Lateral: 70 – 140
• Cranio-Caudal Projection (CC)


  • Routine for all initial x-ray examinations of the breast
  • CC projection combined with MLO
  • Majority of the breast tissue is demonstrated with the exclusion of the extreme medial portion and the axillary tail
• Cranio-Caudal Projection (CC) - Should Demonstrate


  • The nipple in profile & pointing towards the center of the long axis of the film
  • The majority of medial tissue
  • The majority of the lateral tissue with the exclusion of the axillary tail
  • Pectoral muscle demonstrated at the center of the film on approximately 30% of individuals
  • The depth of breast tissue demonstrated should be equal to, or no more than 1 cm less than, the distance from the nipple to pectoral muscle on the medio-lateral oblique projection
• 45 Degree Medio-Lateral Oblique Projection (MLO)


  • The medio-lateral oblique projection is used in all routine mammographic examinations together with the cranio-caudal projection
  • Carefully performed, the lateral oblique mammogram is the only projection in which all the breast tissue can be demonstrated on one film
• 45 Degree Medio-Lateral Oblique Projection (MLO) - Equipment Position


  1. The machine should be rotated through 45°

  2. The top of the breast support table
• Medio-lateral oblique projection (MLO)


  Used in all routine mammographic examinations together with the cranio-caudal projection
• Equipment Position


  1. The machine should be rotated through 45°

  2. The top of the breast support table should be level with the notch beneath the clavicle & humeral head when the woman's arm is by her side
• Anatomical Position - Left Breast


  1. The woman faces the machine with her feet pointing towards the machine

  2. The lateral edge of the thorax should be in line with the edge of the breast support table

  3. The mammographer should stand slightly behind and to the right of the patient
• The 45° medio-lateral oblique mammogram should demonstrate


  • The inframammary angle
  • The nipple in profile
  • The nipple lifted to the level of the lower border of the pectoral muscle
  • The pectoral muscle across the film at an appropriate angle for the individual woman (generate between 20 and 35 degrees from the vertical)