intro to radiology mon: exam1

Medical radiation sciences uses what

Uses energy to create images of the human body

Forms of heat energy

Mechanical, heat, light, chemical, sound, magnetic, electrical and atomic energy

The electromagnetic spectrum looks like what?

A wave

What is Radiography

Electromagnetic energy in the form of X-rays to create medical imaging

Radiography was created when?

November 8 1895

Diagnostic medical sonography

High frequency sound energy to create medical images

Sonography is what

Non ionizing

Magnetic resonance imaging

Energy of high strength magnetic fields and radio waves to create images of the human body

What is the newest modality?

MRI

Computed axial technology

X-ray energy and sophisticated software to create cross-sectional images of the human body

CT does what

It acquires hundreds of views of patient anatomy, as the X-ray tube and detector rotate around the patient.

Ct uses what

Ionizing radiation (a lot more than X-ray)

Nuclear medicine

The nuclear energy of the atom to create medical images

What is the energy form of nuclear medicine

Gamma rays

What is administered to patients to assess physiological functioning

Radiopharmaceuticals

How does nuclear medicine differ

Takes images of radiation coming out of the body rather than going into the body

Cardiovascular interventional technology

Uses X-rays to visualize human blood vessels and heart anatomy

CT requires what?

Use of a catheter and the injection of X-ray contrast material to visualize anatomy

Where are CTs done

Sterile angiography lab

Radiation therapy

High energy ionizing radiation to treat malignant tumors

Radiation therapy targets what

Cancer cells

What modality will tattoo a patient

Radiation therapy target same spot everyday

Mammography

X-ray of breast. Breast tissue for masses.

Types of mammograms

1. Screening : 40 year checkup

2. Diagnostic: mom got it @45 so I get checked @35

Who discovered the role of germs in disease process

Louis Pasteur

Why discovered X-ray

Wilhelm Rontgen

What was the first known X-ray of

Birtha’s hand

Names for radiology

X-ray, medical imaging, diagnostic services, imaging services, imaging.

Health care team includes

Physicians ( medical doctor, doctor of osteopathy) nurses, allied health personal,

X-ray beam energy is produced using what?

High voltage electricity

An image receptor does what

Converts the energy of X-rays into an image

Lowest dosage of ionization is…

50,000

How many volts are in a wall

110 volts

Method to stop electrons and cause energy transformation

Target

Method to accelerate electrons to great speed

Voltage

Source of electrons

Cathode

Remnant radiation

After the radiation has already gone through the patient (what’s left)

absorbed radiation

What has been in the patient

Scatter radiation

Water ballon example. Bounce off.

Primary radiation

What goes directly to the patient

Attenuation

Loss of radiation energy as a result of passing through an absorbing material

High attenuation occurs in

Radiopaque matter

Radiopaque

Hard time going through. White. Punching a wall

Low attenuation occurs in

Radiolucent matter

Radiolucent

Passes through easily. Punching jello.

Kilovolt peak

What does kVp stand for

KVp does what / stands for what

How strong do we need the voltage

Dose

How much + how strong

K

1,000 volts

mA + time (mAs)

How many photons coming out of pt & for how long

Imaging chain

Radiation from X-ray tube through matter to IR

Invisible receptors

Moms job developing images

Latent image

an invisible hidden pattern stored in a light sensitive or radiation sensitive material after it is exposed.

A latent image must do what?

Be processed to convert it to a visible image

Photons

Bundle of energy

Digital radiographs

1. Indirect DR technology

2. Direct DR technology

PSP

Photostimulable phosphor technology

What are some geometric qualities

Good resolution, sharp detail, size and shape.

Signal value variables

Exposure, beam quality, patient characteristics, distance, radiographic grids, X-ray beam modifications, IR characteristics.

What is the good signal value

Combination of these variables being optimized

What affects the visibility of resolution (detail)

Optimum IR

What is a primary factor of receptor exposure

Milliampere-seconds (mAs)

What does mAs represent

They represent the quantity of X-ray production

If patient is larger more mas

If patient is small less mas

Subject density

tissue thickness, tissue composition, pathological conditional

Signal value and subject density have an inverse relationship

mAs reciprocity law

Regardless of the mA and time combinations, the same mAs value will yield the same exposure

KVp is what type of relationship

Direct and non-linear

Poly-energetic

composed of particles or photons that have a range of different levels

Heterogenous

A wide range of different photon energies and wavelengths rather than a single

Distance

Laws of light and intensity as a function of distance ex: flashlight in eyes means a lot of radiation. Further flashlight away less radiation

Beam modifications

1. Filtration

2. Collimation (beam limitation)

3 types of IRs:

1. Film/screen

2. Storage phosphor technology

3. Flat-panel detectors

Digital cassette systems consist of what

Pixel elements in a rectangular array and the resolution is determined by the pixel size of each data element. Ex: phone camera quality.

What is image contrast

It’s due to the shades of gray making up an image

What is automatic rescaling

Computer software optimizes image quality by varying the brightness and contrast of the image on the basis of the exposure to the receptor. Too little exposure results in noisy or grainy images. Too much exposure technique can reduce image contrast.

Image display parameters

Digitally created images are viewed on flat screen television monitors. Images can be adjusted in terms of brightness and contrast.

1. Window level controls image brightness (WL)

2. Window width controls contrast (WW)

Spatial resolution

Often referred to as recorded detail. Described as the sharpness with which an objects structural edges are shown on an image. CRISP.

What is the most common cause of image unsharpness

Motion distortion

What is motion caused by

Involuntary and voluntary

Distortion

Misrepresentation of the true size or shape of the patients anatomy.

2 types of distortion

1. Size distortion

2. Shape distortion

Fluoroscopy

Use of X-rays to create real time images of patient anatomy and function.

Fluoroscopic imaging technology

Image intensifier, flat-panel digital fluoroscopic detector

Images taken during fluoroscopy are what type of images

Digital images

In 1896 Thomas Edison created video playback

In 1904 his assistance, Clarence Daly, died from radiation

Why is it called X-ray?

X means unknown and rays were becoming more popular