Imaging Packet New Bolton

Computed Tomography (CT)

An imaging technique using circular X-ray beams to create 2D cross-sectional "slices."

CT 3D Reconstruction

The process of computer-stacking 2D slices to view sagittal, transverse, or dorsal planes.

Superimposition

An imaging artifact on radiographs that CT eliminates by displaying single-slice cross-sections.

Fan Beam CT

CT type where an X-ray tube and detector rows spin to produce slices.

Cone Beam CT

CT type using a cone-shaped beam with synced rotating tube and detector.

Fluoroscopy

An imaging technique using X-rays to obtain real-time moving interior images.

MRI (Magnetic Resonance Imaging)

Imaging based on the rate at which aligned protons return to their normal state.

MRI RF Shielding (Cage)

A room built around MRI units to prevent outside radiofrequencies from interfering.

MRI Bone Bruising

The only imaging modality capable of differentiating this specific bone pathology.

MRI Safety Rule

The magnet is always on; absolutely no ferrous metals containing iron are allowed.

Radiopharmaceutical

A compound of a radioactive isotope and a pharmaceutical targeted to specific biology.

Gamma Ray emission

Radiation emitted from inside the patient rather than passed through them.

99mTc MDP

The radiopharmaceutical combination used for planar equine bone scan imaging.

18F-NaF

The radiopharmaceutical used for 3-Dimensional PET bone images.

Nuclear Medicine "Hot Spot"

An area of increased radiopharmaceutical accumulation due to high blood flow and osteoblasts.

Biological Half-Life

The time required for the body to eliminate 50% of a substance.

OSL Badge

Optically stimulated luminescence badge using aluminum oxide to monitor personal radiation exposure.

ALARA

As Low As Reasonably Achievable; managed through time, distance, and shielding.

Nuclear Medicine Lead Aprons

Not worn because standard aprons only block low-energy X-rays, not high-energy gamma rays.

X-ray Tube Parts

The cathode (electron source) and the anode (spinning metal target).

Rule of Radiographic Views

Always take at least two views at 90 degrees to each other.

Focal Film Distance (FFD)

The distance from the X-ray tube to the plate.

Object Film Distance (OFD)

The distance from target body part to plate; must be kept minimal.

Kilovoltage Peak (kVp)

Peak voltage applied to X-ray tube determining the highest photon energy.

Milliampere-seconds (mAs)

Measure of radiation quantity over time, directly influencing radiographic density.

Adjusting kVp for Exposure

Must be increased or decreased by 10% to 15% for visible change.

Adjusting mAs for Exposure

Must be increased or decreased by 35% to 50% for visible change.

Ultrasound Transducer Frequency Rule

Higher frequency is for superficial structures; lower frequency penetrates deeper.

Ultrasound Bone Appearance

Appears as a bright white line with a dark shadow beyond it.

Ultrasound Fluid Appearance

Appears completely black on screen because soundwaves do not reflect back.

Anechoic

No echoes produced; appears black on an ultrasound image.

Echogenic

The ability of a anatomical structure to produce echoes.

Hyperechoic

Highly reflective and echo-rich; appears as varying shades of light gray.

Hypoechoic

Less reflective with low echoes; appears as varying shades of dark gray.

Attenuation

The lack of sound transmission through a mass, indicating solid consistency.