Radiology (MD-302)

Radiology

study of X rays and radioactive substances and their uses in the diagnosis and treatment of diseases

X-ray

invisible waves of energy

Nuclear Medicine

medical specialty that uses radioactive substances in the diagnosis and treatment of disease

Radiologist

a medical specialist who uses X-rays in the treatment of disease

Nuclear Physician

radiologist who uses diagnostic nuclear medicine procedures

Radiologic Technologist

works with X-rays, radiation, nuclear medicine, ultrasound

Characteristics of X-rays

• Expose photographic plate
• Penetrate substance
• Invisible
• Travel in straight line
• Scatter
• Ionization

X-ray Studies

radiographic films of structures used for evaluation

Digital Radiography

any method of X-ray image formation that uses a computer to store and manipulate data.

computed tomography (CT)

a series of x-ray images are taken in multiple views (especially cross section)

Contrast Studies

radiopaque substance ingested or injected to expose structures

Barium Sulfate

A contrast medium used for GI imaging

Iodine

A contrast medium used in a majority of non-GI studies

Fluoroscopy

visualization of body parts in motion by projecting x-ray images on a luminous fluorescent screen

Digital Imaging

A filmless method of capturing an image and displaying it by using an image receptor, an electronic signal, and a computer to process and store the image.

Interventional Radiology

the use of radiographic imaging to guide a procedure such as a biopsy

Ultrasound

diagnostic technique using ultrasound waves to produce an image of an organ or tissue

MRI

a technique that uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue

Posteroanterior (PA) view

x-rays travel from a posteriorly placed source to an anteriorly placed detector

Anteroposterior (AP) View

x-rays travel from an anteriorly placed source to a posteriorly placed detector

Lateral View

positioning of the patient so that the side of the body faces the x-ray machine

Oblique View

positioning of the patient so that the x-rays pass through the body on an angle

Abduction

Movement away from the midline of the body

Adduction

movement toward the midline

Eversion

turning outward

Extension

Straightening of a joint

Flexion

bending a joint

Decubitus

lying down on side

Prone

lying face down

Recumbent

lying down (prone or supine)

Supine

lying on the back

Radionuclides

substances that emit radiation spontaneously; also called tracers

• Alpha Particles
• Beta Particles
• Gamma Rays

In vitro

outside the body or in a lab setting

In vivo

Done within the body

Half-life

length of time required for half of the radioactive atoms in a sample to decay

Disintegration

the breakdown of a tablet into smaller particles

Radioimmunoassay (RIA)

test used to measure levels of hormones in plasma of blood via radioactive chemicals and antibodies

radiopharmaceutical (Labeled Compound)

drug that contains a radioactive substance which travels to an area or a specific organ that will be scanned

Scintiscanner (Gamma Camera)

machine used to detect radiopharmaceuticals in the body for diagnostic imaging

• Detects gamma rays

Scintiscan

Image created by gamma radiation, indicating concentration within the body

Bone Scan

uptake of a radioactive substance is measured in bone

Lymphoscintigraphy

a diagnostic test that is performed to detect damage or malformations of the lymphatic vessels using radionuclides

PET scan

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

Single-photon emission Computed Tomography (SPECT)

radioactive tracer is injected intravenously and a computer reconstructs a 3D image based on a composite of many views

technetium Tc 99m sestamibi (Cardiolite) scan

Uptake of a radioactive chemical in myocardium reveals evidence of a heart attack (myocardial infarction).

Thallium (TI) Scan

test that uses radioactive thallium to assess coronary artery disease

Thyroid Scan

scanner detects radioactivity and visualizes the thyroid gland

Conditions Diagnosed with PET scans

• CVA
• Epilepsy
• Alzheimer
• Brain Tumor
• Abd or Pulmonary Malignancy

Conditions Diagnosed with SPECT

• Liver Tumor
• Cardiac Ischemia
• Bone and Spinal Disease

Gamma Rays

high-energy electromagnetic waves emitted by tracers

Ionization

transformation of electrically neutral substances into electrically charged particles

Radiolucent

permitting the passage of x-rays

Radiopaque

substances that do not permit the passage of x-rays

Scan

image of an area, organ or tissue of the body

Tagging

attaching a radionuclide to a chemical and following its path in the body

Ultrasound Transducer

handheld device that sends and receives ultrasound signals

Uptake

rate of absorption of a radionuclide into an organ or tissue

Ventilation-Perfusion Studies

Ventilation and perfusion of a radiopharmaceutical followed by imaging its passage through the respiratory tract

fluoro

(ROOT) luminous

iso

(ROOT) same

pharmacuto

(ROOT) drug

radio

(ROOT) xray

roentgeno

(ROOT) xray

sono

(ROOT) sound

therapeuto

(ROOT) treatment

vitro

(ROOT) glass

vivo

(ROOT) life

-gram

(SUF) record

-graphy

(SUF) process of recording

-lucent

(SUF) to shine

-opaque

(SUF) obsure

cine-

(PRE) movment

echo-

(PRE) repeated sound

ultra-

(PRE) beyond

Radioactivity

The process in which some substances spontaneously emit radiation

Radioactive Decay

A spontaneous process in which unstable nuclei lose energy by emitting radiation

Alpha Particles

positively charged particles with about four times the mass of a hydrogen atom

Beta Particle

a high-speed electron or positron emitted in the decay of a radioactive isotope

Conditions Evaluated with Bone Scans

• Bone Cancers
• Monitors infection
• Monitors trauma

PET-MRI Scan

incorporates magnetic resonance imaging and positron emission tomography to reveal how an organ functions

Iodine-123

radionuclide used mainly for thyroid scans

Technetium IV

A radionuclide used for thyroid scans