Contrast Media in CT
Blood Aspiration, Malpostion or Occlusion
What must be demonstrated prior to administration of any substance into a CVAD to proove the patency of the central line? If this does not occur what can this indicate?
Verify it Can Be Used
What must be done before injecting contrast into a peripherally inserted central catheter?
Start a Separate IV
What must be done if a PICC is not deisgned to handle conrast injection?
Liver
What organ should be scanned 60 seconds after inhection due to its dual blood supply?
Diabetes Mellitus
What pathology increases a patient's risk of developing CIN?
Diabetic Patients
What patients should be prioritized because the fasting can have dangerous implications?
Non-Equilibrium Phase
What phase follows the bolus phase where the contrast is still brighter in the arteries than the parenchyma of the organs, but the venous structures are now opacified?
Higher Viscosity
What physical characteristic does contrast with higher concentration have?
Power Injector
What piece of CT equipment is designed to deliver a blous of contrast in a short period of time and is capable of providing reproducible levels of contrast enhancement?
Hydration
What precaution can greatly reduce the risks associated with injection of contrast?
Insufflation, Absorption, Patient Comfort
What reason is carbon dioxide used over air? (3 reasons)
Programmable Pressure Limits, Audible Alarm
What safety devices are built into the pressure mechanism?
Name of Contrast Used, Dose, Flow Rate, Injection Site
What should be documented when injecting contrast?
Call a Code
What should you do if a patient begins to experience a severe idiosyncratic reaction to contrast?
Stop the Injection
What should you immediately do if a patient begins to experience a mild to moderate recaction?
Stop Injection and Remove Needle
What should you immediately do if a patient is complaining of pain at the injection site?
Enema Tip
What special piece of equipment that is attached to a catheter is used to administer iodinated contrast?
Angiography
What studies are higher concentration contrast agents good for?
Pharmokinetics, Patient, Equipment
What three factors affect the start and end timing of the phases of tissue enhancement?
Orally, Rectally, Injection
What three methods can be used to administer air and gases? (aplha)
Dialysis
What treatment may be temporarily necessary is a patient develops CIN?
Kidney Disease or Renal Failure, GFR and SeCr
What two renal conditions are a major contraindication to IV contrast? What blood tests can be done to check patient's renal function prior?
Close Ended Catheters
What type of CVAD contains a valve that control fluid flow, prevents relux of blood into catheter and only requires a saline fush to maintain patency?
Dialysis
What type of catheter should never be used for contrast administration?
Time-Density Curves, Aortic
What type of graph depicts the effects of aortic and hepatic enhancement? Which version has more pronounced effects?
Chemotoxic
What type of reaction results from physiochemical properties of the contrast, the dose of contrast and the speed at which the contrast is injected?
Antecubital,
What vein is preferred when using a power injector?
Increase
What will happen to the SeCr levels of a patient who has consumed at lot of cooked meat?
Location, Age of Catheter, Unaccessed Connecting Hub or Port, Condition of Surrounding Skin
When a patient arrives into the CT department with an exisiting IV line what factors need to be evaluated first before it can used?
Joint Spaces
When something is injected intraarticularily, where are we injecting this?
Non-ionic
When the molecules of an iodinated water-soluble solution do not dissociate in the blood stream, what is it said to be?
Orally
When used as a contrast medium what is the only way water is administered?
Lower Injection Rate, Decreased Volume
When using a contrast agent with higher concentration how can you maintain an adequate enhancement?
Syringe, No it Only Maintains the Temperature, 37°C
Where does the warming device attach to? Does it heat the contrast? What temperature is the contrast?
Test Bolus
Which automated injection triggering method utilizes an injection of 10-20 mL of contrast delievered at the same rate as the diagnostic scan to perform trial scans to determine the length of time from injection to peak enhancement?
Kidneys
Which organ has a peak enhancement of 80 to 120 seconds due to the fact that it is one of the last organs to receive the contrast?
Men, Younger Pt, Blacks
Who will have greater levels of SeCr? -men or women -younger pt or older pt -blacks or whites
Differentiates, Density, Contrast
Why is contrast media used in CT? It ________________ between structures of similar ______________. Plainly said it increases the ____________________.
Not Metabolized, Water-Soluble, Easy to Administer, Large Attenuation Differences
Why is iodinated water-soluble contrast used? (NWEL)
Uniphasic
What is the word used to decribe a single flow rate that is used during a CT scan?
Durable, Prevents Mixing of Medications
What it the major advantages to a using a CVAD?
Plasctic Cannula
What kind of needle is required due for increased flexibilty?
Extravasation, Vascular Studies
What is a risk of the bolus triggering method due to the tech not being able to remain in the room? So what study should this only be used for?
Open Ended Catheter
What is a type of CVAD must be clamped when not in use and should be flushed with heparinized saline to maintain the patentcy between uses?
Arterial Phase
What is another name for the bolus phase?
Venous Phase
What is another name for the non-equilibrium phase?
It is Accidentally Injected into Surrounding Tissue
What is extravasation of contrast media?
Leaks into Surrounding Tissues
What is infiltration of contrast media?
Arthrograms, GI Studies, Postmyelograms, Solid Organ Enhancement, Vascular & Arterial Studies
What is iodinated water-soluble solution for? (5)
Can Decrease the Accuracy of Imaging During Peak Aortic Enhancement, Trigger Scan Acquisition Early
What is major limitation of bolus triggering involving the delay between the last monitor scan and the start of scanning? How is this overcome?
Liver
What is one of the worst organs to scan during the equilibrium phase?
10
What is the AVID during the equilibrium phase in HU?
10 to 30
What is the AVID during the non-equilibrium phase in HU?
Pulomnary, Cardiovascular
Although generally safe overdoses of contrast can occur and be fatal, what systems do it affect? (2)
Sterile
Any needle that accesses a CVAD must be what?
Contrast Induced Nephropathy
What is the acute impairment of renal function due to the administration of IV contrast?
Dialysis, End-Stage Renal Failure
Any patient who is temporarily on this treatment should not receive contrast as it can lead to chronic kidney failure. However a patient with this condition can receive contrast as no further damage can happen to the kidneys.
0.1%, 15-30, Water
What is the concentration of VoLumen? What is that in HU? What substance does it resemble?
Equilibrium Phase
What is the final phase that occurs approximately 2mins after the bolus phase where contrast is emptied from the arteries, diluted from the veins and has soaked the organ parenchyma?
Temporarily
A contrast medium is and agent that __________________ ehances differences between anatomical structures.
Decreased
A malnourished patient or someone with msucle wasting will have increased or decreased SeCr levels?
2, 24, 30
A patient with normal renal function can eliminate half the doage of contrat in how many hours? How long until complete elimination? How long can the half-life increase to in a patient with impaired function?
Allergies to Food, Drugs or Other Substances
A patient with this condition is two times more likely to have an adverse reaction to contrast. Beta-blockers can be used to impair the response to contrast.
Asthma
A patient with this respiratory condition is three times more at risk to develop adverse reactions to contrast.
Bolus Phase
What is the first phase of enhancement that immediately follows the injection of an IV bolus, takes 15 to 22 seconds to reach peak and the arterial structures are filled with contrast?
Glomerular Filatration, Serum Creatinine
What is the golden standard when is comes to measuring renal function prior to contrast administration? What is another way to estimate this although not as accurate? (no abbrv)
Yes
Are pharmokinetic factors controllable?
Bolus-Shaping
What is the manipulation of the flow-rate to change the characteristic of the time-density curve?
IV
What is the most common administration method of iodinated contrast?
1, 3
Barium Sulfate for CT is specially formulated with a concentration of ___ to ___ %.
Iodinated Water-Soluble Solution
What is the most commonly used contrast medium used in CT?
Avoid Using HOCM
What is the most important method of reducing a patient's risk of developing an idiosyncratic reaction?
VoLumen
What is the name of a unique barium used in CT with a low HU?
Large Bowel Visualiztion
What is the only use/exam for the rectal administration of iodinated contrast?
No, They are Unrelated
Can a larger dose of contrast create a larger idiosyncratic reaction? Why?
No, it Requires Special Training
Can a technologist access an implanted port such as tunneled central venous catheter?
Ensures the Imaging During Peak Enhancement Regardless of Pateint
What is the purpose of automated injection triggering?
Connecting Tubing, Air Bubbles, Vein Patency
Considertations of using a Power Injector: -what must be able to withstand the pressure delivered by the power injector? -what must be cleared from syringes and tubing prior to connection? -what must be checked using blood aspiration, resistance, and saline flush?
Central Nervous System
Contrast is contraindicated in a patient with a disorder of this system because it disrupts their blood brain barrier and are at a higher risk of seizures.
Greater Peak Enhancement, Greater Time to Reach the Peak
What effect occurs if you increase the contrast volume if the injection rate is held constant?
Evaluation of the Pancreas, GI Studies, Gastric Neoplasm
What exam is water commonly used as a contrast agent? (3)
Arthrograms, GI Studies, Myelogram, Virtual Colonoscopies
What four exams are air and gases used for? (aplha)
30
During the bolus phase what is the HU difference between the aorta and the IVC (or AVID, arterovenous iodine difference)?
Non-Equilibrium
During what phase is most routine (or non-angiography) images acquired?
Normal
Feeling of heat/warmth, voiding sensation, mild flushing, metallic tate, neausea, and vomiting are all examples of what kind of reaction?
Chemotoxic Response
Hemodynamic disturbances, injuries to organs and vessel, pain at the injection site, and contrast induced nephropathy are all examples of what kind of response to contrast.
By Weight
How are pediatric doses calculated?
Inform Patient of Reactions Prior to Administration
How can anxiety that can increase the likelihood of normal reactions and side effects be decreased?
Day, Weeks, Months, or Years
How long can a CVAD be used?
48 Hours, Lactic Acidosis
How long should a patient taking metformin withold their medication after a contrast injections? What potential dangerous pathology can occur if the kindeys can't remove the metformin and it accumulates?
2, Liquid, Paste, Liquid, Esophageal Studies
How many forms does Barium Sulfate come in for CT? What are the two forms? Which has low concentration and viscosity? What exam is the high viscosity barium typically used for?
Darker, Air
How will a negative contrast make a CT image appear? What is an example of this type of contrast?
Lighter, Barium Sulfate, Iodinated Solution
How will a positive contrast agent make a CT image appear? What are two examples of this? (alpha)
Carbon Dioxide
What gas is often preferred over air as a contrast agent?
Previous Contrast Reaction
If a patient has experienced this condition they are eleven times more likely to have an adverse reaction, making this one of the most important indicators of relative risk.
Decrease Time to Reach Peak Enhancement
If the flow rate is increase for a contstant volume of contrast what is the result?
Blood Brain Barrier Disruptions, No, 4 mins
In a routine scan of the head what pathology is being looked at if enhancement is being used? Does the injection rate matter? Typically how long is the scan delay for the brain?
Gas, Liquid, Paste/Powder
In terms of consistency what are the three main forms of contrast?
Increases, Direct
Increasing the volume of contrast ______________ the risk. It is a __________ relationship.
Fluoroscopy
What guidance tool/method is require for the injection of contrast into joint spaces or the spinal column?
LOCM, IOCM, Hydrated, Smallest, Metformin
Methods for preventing CIN include: -using ________ or _________ (osmolality) -ensuring a patient is well __________________ prior to the exam -using the _______________ possible dose -temporarily discontinue medications such as ________________
Add 3 Seconds
What is the rule of thumb when the delay is calculated in the test bolus method?
48
The common practice is to limit a patient to one contrast injection per how many hours?
Streaks, Needs to be Diluted, Allergic, Mucosal, Complications, Contraindications
The cons of barium are: -it can cause these on the image -this needs to happen b/f it's used -this type of reaction can occur -is has poor ______________ evaluation -and these can occur from use -sometimes will not work with certain pathologies
Decreased, Smaller Bore
The flow rate needs to be adjusted how and what kind of bore should be used when using a smaller vein?
Severe
The following signs and symptoms are indicative of what classification of idiosyncratic reaction? -abrupt onset -bradycardia -hypotension -severe dyspnea -cardiac arrhythmias -laryngeal swelling -convulsions/seizures -loss of consciousness -respiratory or cardiac arrest
Heart Disease, Hypertension
What is a contraindication to contrast due to fact that it cause weakened and narrow blood vessels and can cause changes in BP and cardiac output?
Hyperthyroidism
What is a contraindication to contrast due to the facy it can increase thyroid hormone levels resulting in a fatal thyroid storm?
Idiosyncratic
This type of reaction is completely unpredictable and can occur anywhere from minutes to 1 hours. The reactions are described as allergic-like and children have a lower incidence.
Elevated SeCr, 7 to 10 Days
What is a key indicator of CIN post injection that occurs 24-48 hours after? How long should is take these levels to return to normal?
It Can Cling
What is a major pro of barium when it comes to the bowel walls?
Better Distention, Slower Transit Time, Improved Bowel Wall Visualization
What advantages does VoLumen provide over water? (3)
Ensure That Arm is Straight, Proper Dose Delivered, Stable Vein is Used, Choose Large Vein, Choose Large Bore Catheter
What are a few ways to prevent either infiltration or extravasation?
Veins, Arteries, Solid Organs
What are being enhanced when iodinated contrast is injected?
Allergic-Like Reactions, Contraindications, Diarrhea, Poor Coating
What are cons to using iodinated water-soluble solution? (ACDP)
Double Contrast Study, Yes
What are studies with more than one type of contrast called? Can this be done with two contrast agents of the same classification?
Non-Toxic, Radiolucent, Readily Absorbed, Distends the GI Tract
What are the chracteristics of air and gases? (4 reasons)
Poor Bowel Distention, Rapid Transit Time
What are the cons to using water as a contrast medium? (2)
Intraarticular, Intrathecal, Intravenous, Oral, Rectal
What are the five wat iodinated contrast can be administered? (no abbrv)
Warming Device, Syringe, Pressure Mechanism, Control Panel
What are the four components of a mechanical injector?
GI Studies
What are the only exams where barium is used?
Cost Effective, Easily Accessible, Low Density, No Allergies
What are the pros to using water as contrast? (4)
Mild, Moderate, Severe
What are the three classifications of idiosyncratic reactions?
High Osmolar Contrast Medium, Low Osmolar Contrast Medium, Isosmolar Contrast Medium, HOCM, IOCM
What are the three levels of osmolality of contrast? (no abbrv.) Which is the most likley to cause adverse reactions? Which is the safest to use? (abbrv. for last 2)
Hand, Drip Infusion, Mechanical Injector, Mechanical Injector
What are the three methods of injecting contrast? Which is the most common?
Bolus, Non-Equilibrium, Equilibrium
What are the three phases of tisse enhancement?
Positive, Negative
What are the two classifications of contrast depending on its attenuation value?
Test Bolus, Bolus Triggering
What are the two types of automated injection triggering?
Orally, Rectally, Orally
What are the two ways that barium is administered in an enhanced exams? Which is more common?
Ominpaque, Optiray, Visipaque
What are three commonly used iodinated contrast agents that are inejcted?
Gastrogafin, Telebrix
What are two names of orally administered iodinated contrast?
Streaking
What artifact can occur from the use of higher concentration contrast?
Bolus Triggering
What automated injection triggering method uses the contrast bolus itself to intiate the scan acquisition by placing an ROI in a single slice and taking a series of low-dose scan and once the desired HU is achieved triggers the computer to start the scan?
Air
What can never be injected intravenously?
Barium, Water
What cannot be aministered to the spinal column via intethecal injection?
Mild to Moderate
What classification of idiosyncratic reactions are the following signs and symptoms? -itchy skin -hives/rash -nasal congestions -coughing/laryngeal swelling -peripheral tingling -tachycardia or bradycardia -hypotension -tightness -anxiety
Control Panel
What component of the mechanical injector enables the technologist to manipulate the injection parameters (flow rate, volume, pressure limit) and stores the injection parameter protocols into their memory?
Pressure Mechanism
What component of the mechanical injector is considered the body of the system and consists of an electromechanical motor used to drive the piston movement?
Syringe
What component of the mechanical injector is removable, pre-sterilized and disposable, and contains the piston for contrast loading and delivery?
Central Venous Access Device
What device is designed to deliver medications and fluids directly into the IVC, SVC, or right atrium?
Spinal Column
What does something intrathecal refer to?
