Radiologic Technology: Computed Tomography Exam Review

Flashcards created for the review and understanding of key concepts related to Computed Tomography and Radiologic Technology as per the provided lecture notes.

Negative contrast agents

Include substances like Air, used in imaging to create differences in densities.

Oral contrast purpose

Used to enhance vascular structures and delimit the gastrointestinal (GI) tract.

Appropriate action for diabetic patient with elevated creatinine

Use low-osmolar contrast and hydrate patient.

Urticaria and mild dyspnea classification

Classified as a mild reaction following contrast injection.

Increased risk for patients with asthma

Increased risk for anaphylaxis when receiving contrast.

Osmolality in contrast media

Describes the number of dissolved particles in the solution.

Ionic contrast agents

Characterized by dissociation into charged particles.

Increasing iodine concentration effect

Generally increases viscosity of the contrast agent.

Primary mechanism of contrast enhancement

Increase attenuation of x-rays.

Positive contrast agents

Defined as those that increase attenuation relative to tissues.

Contrast extravasation management

After stopping injection, the limb should be elevated and monitored.

Safest contrast strategy for pediatric patients

Weight-based dosing.

Shellfish allergy relation to iodine contrast

Iodine allergy and shellfish allergy are unrelated.

Extravasation risk factors

Increases with the use of fragile veins.

Concern for metformin patient receiving contrast

Risk of lactic acidosis.

Most appropriate contrast for borderline renal function

Use isosmolar contrast agents.

Warming contrast media benefit

Reduces viscosity of the contrast agent.

Complication monitoring in Graves' disease

Monitor for thyroid storm.

Warm flushed sensation after rapid bolus contrast

Expected physiologic response.

Hypotension and bronchospasm classification

Classified as a severe life-threatening reaction.

Delayed images in CT urography

Obtain to evaluate contrast excretion into the collecting system.

Osmolality closest to blood

Isosmolar contrast media.

Metallic taste during injection indication

Normal transient side effect of contrast.

Factor influencing enhancement of solid organs

Contrast injection rate and volume.

Safe step for dehydrated patient scheduled for contrast CT

Hydrate before contrast administration.

Allergic-like reactions to contrast

Described as idiosyncratic.

Rate of contrast elimination terminology

Referred to as clearance.

Primary influence on half-life of contrast media

Renal function.

Risk factor for chemotoxic reactions

High osmolality of the contrast agent.

Type of non-dose-dependent reaction

Idiosyncratic reaction.

Delayed reaction timing

Typically occurs hours to days later.

Most appropriate agent for intravascular CT imaging

Biodinated contrast.

Contrast bolus geometry determinant

Flow rate and duration.

Requirement for high-viscosity contrast media

Higher injection pressure.

Risk of high-viscosity contrast injected rapidly

Increased resistance in veins.

Common route for CT contrast administration

Intravenous administration.

Effect of viscosity on radiation dose in CT

Higher viscosity can affect injection pressure.

Extravasation definition

Refers to contrast leaking into tissues.

Effect of warmed contrast media

Decreases viscosity.

Physiologic parameter for renal function pre-contrast

Serum creatinine and Blood Urea Nitrogen (BUN) levels.

Increase in kVp impact

Increases photon energy and dose.

CT dose management primary goal

Optimize diagnostic quality with minimal dose.

Increased length of scan impact

Increases Dose-Length Product (DLP).

CTDIvol representation

Average dose within the scan volume.

How Dose-Length Product (DLP) is calculated

CTDI multiplied by scan length.

Consequence of increasing pitch

Results in decreased dose.

Stochastic risk in patient groups

Highest in pediatric patients.

Result of overranging in helical CT

Extra dose beyond planned imaging range.

Thyroid shielding during chest CT effect

Reduces dose by blocking scatter reaching superficial organs.

Increasing pitch from 0.8 to 1.5 effect

Decreases dose during imaging.

Reason for rarity of deterministic effects in CT

CT rarely exceeds tissue reaction thresholds.

Repeat scans affect on dose

Significantly increase cumulative dose.

Children's CT dose relative to body mass

Higher due to smaller bodies absorbing more beam energy.

Greatest risk for fetus exposed during abdominal CT

Long-term stochastic cancer risk.

Dose reduction strategy without quality loss

Lowering mAs with iterative reconstruction.

Dose modulation systems function

Adjusting tube current based on patient anatomy.

Justification in radiation protection

Performing CT only when clinically indicated.

ALARA principle for technologists

Optimize technique to achieve diagnostic images at the lowest reasonable dose.

Final verification responsibility in CT orders

The CT technologist.

Essential room preparation step before patient arrival

Scanner calibration and warm-up.

Minimum identification methods for patient safety

Two methods should be used.

Systolic pressure definition

The peak pressure during heart contraction.

Pulse site in elbow cavity

Brachial pulse.

Standard blood pressure cuff inflation level

200 mm Hg.

Full and bounding pulse characteristics

Strong and regular.

Vital sign measured by observing chest movement

Respirations.

Hypertension clinical definition

Abnormally high blood pressure.

Next step for protocol discrepancy

Consult with the radiologist.

Critical medication information for CT technologist

Helps evaluate safe clearance of contrast media.

Next pulse site if radial pulse is absent

Carotid pulse.

Interpretation of blood pressure 150/95 mm Hg

The patient is experiencing hypertension.

Importance of order verification step

Acts as the final safety barrier before radiation exposure.

Protocol selection factor while preparing room for CT

Scanner Capabilities.

Patient anxiety impact on CT scan quality

May cause motion artifacts; coach patient on breathing.

Diastolic pressure interpretation from blood pressure reading

90 mm Hg.

Reason for verifying pregnancy status in CT

Factors that could lead to cancellation or modification of the scan.

Anatomy identification terms

Include maxillary sinus, sphenoid bone, and zygoma.