Computed Tomography

Monitoring During the Examination

Continuous observation through the control-room window, cameras, and the intercom lets the technologist respond quickly to adverse events. Patients receiving contrast are watched closely during and immediately after injection. Patients with compromised status may require pulse oximetry, ECG, or blood pressure monitoring, and the technologist must recognize abnormal values and respond according to protocol.

Parameter	NormalAdultRange	Notes
Heartrate	60–100beats/min	Below60bradycardia(goalforcoronaryCTA);above100
		tachycardia
Respiratoryrate	12–20breaths/min	Risingratecansignalrespiratorydistressoranxiety
Bloodpressure	Below120/80mmHg	Hypotensionwithbradycardiasuggestsavasovagal
		reaction;hypotensionwithtachycardiasuggests
		anaphylaxis
Oxygen saturation (SpO 2)	About95–100%	Belowabout90%requirespromptaction
Temperature	About 97 .8–99 .1 °F (36 .5–37 .3 °C)	Fevermayaccompanyinfection

ECG patterns matter most in cardiac CT. A regular sinus rhythm allows reliable gating; atrial fibrillation, frequent premature ventricular contractions, and other arrhythmias cause misregistration. Life-threatening rhythms such as ventricular fibrillation or asystole call for an immediate code response. The technologist also assesses level of consciousness (alert and oriented to person, place, time, and situation) and fall risk, never leaving a sedated, confused, or elderly patient unattended on the table.

Accessory Medical Devices

Device	TechnologistResponsibilities
Oxygendelivery	Maintain the prescribed flow during transfer and scanning Nasal cannula about 1–6 L/min; simple .
	mask about 5–10 L/min; nonrebreather mask about 10–15 L/min Use portable tanks with adequate .
	supplyandsecurethem
Chesttubes	Keepthedrainageunitbelowthelevelofthechestandupright;donotclampordisconnect;avoid
	tensionorkinksduringtransfer
Indwellingurinarycatheters	Keepthecollectionbagbelowthelevelofthebladdertopreventreflux;avoidtensiononthetubing;
	thecathetercanbeclampedonlyforprotocolssuchasretrogradecystography

Device	TechnologistResponsibilities
IVlinesandpumps	Keepinfusionsrunningunlessthecareteamdirectsotherwise;avoiddislodginglineswhenmoving
	thetable
Ventilatorsandmonitors	Transportwithqualifiedpersonnel;routetubingandcablessothetablecanmovefreelythroughthe
	gantry

Ergonomics and Safe Transfers

Safe transfer protects both patient and staff. Lock stretcher and wheelchair wheels, lower the table to transfer height, use slide boards, transfer sheets, or mechanical lifts for dependent patients, and have enough staff before moving the patient. Verify the patient's weight against the table weight limit before scanning bariatric patients, and confirm that the body fits the gantry aperture. Technologists use proper body mechanics: a wide base of support, bending at the knees, keeping the load close, and pushing rather than pulling.

Special Patient Populations

Age-appropriate communication, a parent present with

Multiple comorbidities, reduced renal function, hearing and

protection when helpful, feed-and-wrap or swaddling for

vision changes, fall risk, fragile skin and veins, and kyphosis

infants, immobilization devices, sedation per protocol, and

that complicates positioning; allow additional time.

child-sized technique factors.

Infection Control

Standard precautions apply to every patient: hand hygiene before and after contact, gloves when contact with blood or body fluids is possible, and additional PPE for splashes. Transmission-based precautions add contact (gown and gloves; for example MRSA, C. difficile), droplet (surgical mask; influenza, pertussis), or airborne measures (fit-tested N95 respirator; tuberculosis, measles, varicella). The CT table, positioning aids, and gantry surfaces are cleaned with an EPA- registered disinfectant between patients, following the product's contact time. C. difficile spores require a sporicidal (bleach-based) disinfectant and soap-and-water hand washing, because alcohol hand rub does not kill spores.

Level	Defi nitionandExamples
Cleaning	Removalofvisiblesoilandorganicmaterial;alwaysprecedesdisinfectionorsterilization
Disinfection	Destructionofmostpathogenicmicroorganismsonsurfacesandequipment(theCTtable positioning ,
	sponges injectorheads) ,
Sterilization	Destructionofallmicroorganisms includingspores;requiredforinstrumentsthatentersteriletissueor ,
	thevascularsystem(biopsyneedles arthrographytrays) ,

Sterile technique is used for CT-guided biopsy and drainage, arthrography, myelography, and central line access: a sterile field, sterile gloves, skin antisepsis, and no crossing of the sterile field. Aseptic technique (clean gloves, skin antisepsis, sterile catheter) is used for peripheral IV placement.

Medical Emergencies

CT technologists maintain basic life support certification and know the location and contents of the crash cart. When an emergency occurs, the technologist stops the scan, stays with the patient, calls for help (a code or rapid response team as appropriate), retrieves the crash cart and AED, and begins CPR if the patient is unresponsive and not breathing normally. Other emergencies include seizures (protect the patient from injury, turn to the side, do not restrain or place anything in the mouth), hypoglycemia (give glucose if the patient is alert, or follow protocol), syncope, and cardiac arrest. Every adverse event is documented according to facility policy.