Mammography Techniques and Principles

Mammography Methods

• Three common mammogram types are film-screen, digital, and 3D digital mammograms.

Mammography Composition

• Mammogram images are created by X-rays passing through breast tissue and interacting with a digital detector.
• The anode in the X-ray tube used for mammography is made of molybdenum or rhodium, not tungsten, which is used in general X-ray tubes.

Mammography kVp and mAs

• Statistical analysis of imaging performance characteristics for mammography units operated at 25 and 26 kVp was conducted.
• The required mAs value at 26 kVp is approximately 15% lower than at 25 kVp.
• The range of mAs used for generating a phantom image is roughly 70 to 120 mAs.

Mammography Radiation Dosage

• Modern mammogram machines use low radiation doses to produce high-quality breast X-rays.
• The average radiation dose for a typical mammogram (two views per breast) is approximately 0.4 millisieverts (mSv).

Mammography Components

• Essential components include an X-ray generator, an image detector, and a breast compression paddle.
• The generator and detector are set at a fixed distance and oriented orthogonally.
• The entire unit can be rotated to capture the necessary mammographic views.

Calcaneus X-ray (Heel X-ray)

• A calcaneus X-ray, known as a calcaneus series or calcaneus radiograph, is a set of two X-rays of the calcaneus (heel bone).

Anode Heel Effect

• The anode heel effect is a decrease in X-ray field intensity toward the anode in X-ray tubes.
• This is due to lower X-ray emissions at angles perpendicular to the electron beam and higher absorption at the anode end.
• Reduced X-ray fluence and higher mean radiation energy occur in the anode direction.
• This variation in intensity is because of how electrons strike the anode target at varying angles.

Anode Angle

• The anode angle is the angle between the vertical and the target surface in X-ray tubes.
• Most X-ray tubes have an anode angle of 12-15 degrees.
• A smaller angle results in a smaller effective focal spot.
• Not every part of the anode is involved in X-ray production.

Tomography (3D Imaging)

• "3D CT Scanner" is an abbreviation for Computed Tomography 3D Scanner, a system using X-rays to define 3D object size.
• Computed tomography is a diagnostic imaging technique that uses a combination of X-rays and computer technology to produce images of the inside of the body.
• Tomography images are used to show bones, muscles, fat, organs, and blood vessels.

Positron Emission Tomography (PET) Scan

• A positron emission tomography scan is also known as a PET scan.
• PET scans are often used in cancer treatment.
• PET scans can be combined with CT scans (PET-CT scans).

CT Scan Contrast Agent

• Radiologists use iodine-based contrast medium (ICCM) to enhance CT images for accurate diagnosis.
• Certain tests, like CT angiograms, require ICCM.

Tomography as a Radiology Technique

• Tomography is a radiologic technique to create clear X-ray images of deep internal structures.
• By focusing on a specific plane within the body, it helps visualize structures obscured by overlying organs and soft tissues.

Contrast for Tomography

• Types of contrast include intravenous (IV), oral (PO), and rectal (PR).
• IV contrast can either be gadolinium for MRI or iodine-based contrast for CT.
• PO contrast for ER and inpatient CT scans is dilute iodinated contrast similar to IV CT contrast.