contrast and imaging

positive contrast media

increase attenuation and appears radi opaque, absorbs or blocks x ray (white)

positive contrast example

barium sulfate and ionized contrast

negative contrast media

decrease attenuation and appears radiolucent, passes through x ray (dark/black)

negative contrast example

carson dioxide and air

barium

used for esophageal, gastral, intestinal examinations if perforation is NOT suspected

ionized contrast

water soluble, is suspicion of perforation or leak

kilovoltage peak

kVp, primarily controls beam energy (penetration), influences contrast

mila amperage and time (seconds)

mAs, controls quantity of x ray photons

radiograph

image of anatomical part

view

the image or part as seen from vantage point of IR

projection

path of CR as it passes through the patient

Chest x-rays

the most common and repeated exam

types of sheilidng aprons

0.25 mm (required by law) and 0.5mm (better), never crumple or fold

SID

source to image distance

OID

object (patient) to image distance, used to magnify

types of Body habitus

hypersthentic, sthenic, hyposthenic

hypersthentic

5% of people, stocky massive body type, thoracic cavity is wide and deep, gallbladder and stomach high and transverse

sthenic

near average, 50% of pop, slightly heavier w/ muscle, chest and abdomen near average

hyposthenic

more slender, 35%, gallbladder sits vertical and stomach is J-shaped

asthenic

10% of pop, extremely slender, thoracic cavity is narrow and shallow, low diaphragm, gallbladder is vertical, stomach is J shaped