General Flashcards
Vital Signs
temp, pulse, blood pressure, respirations
normal body temp
97.7-99.5
pulse rate for adults
60-100 bpm
pulse rate for kids
70-120 BPM
systolic pressure
indicates pressure within arteries. should be less than 120 mm Hg
diastolic pressure
measure during relaxation of the heart should be less than 80 mm Hg
normal respiration for adults/ kids
12-20
20-30
cardiac cycle
series of blood flow-related events that occur from the beginning of one heartbeat to that of the next.
systole vs diastole
contraction vs. relaxation
3 distinct stages of cardiac cycle
atrial systole, ventricular systole, complete cardiac diastole.
atrial systole
contraction of the left and right atria.
corresponds to P wave on ECG
Ventricular systole
contraction of the left and right ventricles.
corresponds to the beginning of the QRS complex on ECG.
Complete Cardiac Diastole
period of relaxation after heart contraction.
consists of ventricular diastole and atrial diastole.
corresponds to the T wave of the ECG
When are cardiac CT images typically acquired
diastolic phase
preferred heart rate for optimal cardiac imaging on most MSCT systems
65 bpm
Blood Urea Nitrogen (BUN)
laboratory value used to indicate renal function.not sufficient indicator by itself. normal range: 7-25 mg/dL
Creatinine (Cr)
lab value used to indicate renal function.
normal levels 0.5-1.5 mg/dL
BUN/ Creatinine ratio
sometimes used to evaluate renal function. normal is 6:1-22:1
GFR
Glomerular Filtration Rate: more accurate measure of renal function. approximation of creatinine clearance. normal GFR: men: 70(+-)14
women: 60(+-)10
PT
prothrombin time: measure of blood coagulation.
normal range: 12-15 seconds.
normal INR range
0.8-1.2
PTT
partial thromboplastin time:used to detect abnormalities in blood clotting.
normal range: 25-35 seconds
elevate D-Dimer =======
recently degraded blood clots
Aseptic technique
practices and procedures used by practitioners to reduce the risk of infection during IV administration of contrast media
components of aseptic technique
- thorough hand washing between patients
- wearing of disposable gloves
- cleaning venipuncture site with alcohol swab
- gentle pressure with alcohol swab to venipuncture site after removal.
Sterile Technique
establishing a field around area of interest free of all microorganisms.
max flow rate for 22G angiocath
3 mL/s
single-phase imaging
image acquisition occurs at a single specific time during or after the injection of the contrast agent.
Multiphase Imaging
involves the acquisition of multiple series of CT images over time intervals.
RCM
radiopaque contrast media.
Osmolality
characteristic of an iodinated RCM. describes the agents propensity to cause fluid from outside the blood vessel(extravascular space) to move into the blood stream(intravascular space)
greatly effects potential for adverse effects on patient.
Ionic Contrast Media
salts consisting of sodium and/or meglumine. Each molecule of ionic contrast consists of 3 iodine atoms. When injected into the bloodstream, each molecule disassociates into two charged particles or ions. high osmolar
Non-Ionic Contrast Media
non-salt chemical compounds that also contain 3 atoms of iodine per molecule. they do not disassociate in solution. low osmolar
IOCM
iso-osmolar contrast media: same osmolality as blood.
rate of serum iodine concentration for adequate opacification during CT exam
2-8 mg/mL
intrathecal
injection into the space surrounding the spinal cord
intra-articular
injection directly into joint space. performed during CT arthrography.
4 H’s as outlined by the ACR
- History
- Hydration
- Have (equipment ready)
- Heads up (constant assessment of patient)
CIN
contrast induced nephrotoxicity, a severe delayed reaction. considerable decline in renal function after receiving contrast media.risk is directly related to patients preexisting renal function.
source detector distance
as the distance from the x-ray tube to the detectors decreases, dose increases.
Filtration in CT x-ray tube
between 6-9 mm (Al) or equivalent
Filtration in CT x-ray tube
between 6-9 mm (Al) or equivalent
bow tie filters
added to CT x-ray tube to compensate for no cylindrical nature of most body shapes.
bow tie filters
added to CT x-ray tube to compensate for no cylindrical nature of most body shapes.
Inherent absorption efficiency
describes the ability of the detector to capture transmitted x-ray quanta and produce the appropriate response.
Inherent absorption efficiency
describes the ability of the detector to capture transmitted x-ray quanta and produce the appropriate response.
geometric efficiency
describes the spatial arrangement of detector elements, including the amount of interspace material required between adjacent elements.
> interspace material=patient dose
geometric efficiency
describes the spatial arrangement of detector elements, including the amount of interspace material required between adjacent elements.
> interspace material=patient dose
beam shape MSCT vs traditional
MSCT uses cone shaped beam instead of fan shaped
beam shape MSCT vs traditional
MSCT uses cone shaped beam instead of fan shaped
adaptive filters
noise reduction algorithms employed during the reconstruction process to reduce displayed noise within the CT image.
dose profile
the section of the patient exposed to radiation
adaptive filters
noise reduction algorithms employed during the reconstruction process to reduce displayed noise within the CT image.
3 basic principles of radiation protection of the CT patient?
strict clinical indication
protocol optimization
shielding
dose profile
the section of the patient exposed to radiation
3 basic principles of radiation protection of the CT patient?
strict clinical indication
protocol optimization
shielding
absorbed dose
describes the amount of x-ray energy absorbed in a unit of mass. (Gy)
absorbed dose
describes the amount of x-ray energy absorbed in a unit of mass. (Gy)
air kerma
describes the amount of radiation in a quantity of air
air kerma
describes the amount of radiation in a quantity of air
effective dose
accounts for the type of tissue that the radiation is deposited in. Takes into account different types of tissue. approximates relative risk from exposure. (Sv)
effective dose
accounts for the type of tissue that the radiation is deposited in. Takes into account different types of tissue. approximates relative risk from exposure. (Sv)
CTDI
CT dose index, approx measure of the dose received in a single CT section or slice.
CTDI
CT dose index, approx measure of the dose received in a single CT section or slice.
azimuth
the angle of the tube and detectors in relationship to the patient position during scout acquisition.
azimuth
the angle of the tube and detectors in relationship to the patient position during scout acquisition.
slip ring technology
eliminates the need for cables by utilizing a system of contact brushes that supply electricity to power the system and enable the passage of transmission data to the computer system.
slip ring technology
eliminates the need for cables by utilizing a system of contact brushes that supply electricity to power the system and enable the passage of transmission data to the computer system.
