CAT SCAN REGISTRY 2026 - Labs

P wave

the first wave in an EKG. Represent electrical activity through the atria

QRS Complex

Represent electrical current through the ventricles - aka “ventricle systole”

ST Segment

Represent ventricle contracting but no electrical activity is following through it

T Wave

Represent electricity in ventricles for the next muscle contraction - aka “ventricle diastole”

EKG Gating

Creates images of the heart only when its at rest between beats. Doing this minimizes motion blur.

Kidney function and blood clotting

Types exams used for CT that demonstrates PT ability to use contrast and IV

Types of kidney function tests

Blood urea nitrogen (BUN), Creatine, and Glomerular Filtration Rate (GFR)

BUN - normal value

7 to 25 mg/dL

BUN value above 25 mg/Dl

Means kidney function is struggling to function. Contrast should not be used

BUN value above 50 mg/Dl

Mean kidney function is failing and is going through renal failure. Contrast should not be used.

Creatinine - normal value

0.5 to 1.5 mg/dL

Normal BUN/creatinine ratio

approximately 6:1 to 22:1

Estimated Glomerular filtration rate (eGFR)

An approximation of creatinine clearance or the rate by which creatinine is filtered from the blood stream.

Normal eGFR measurement

greater than 90 to 120 mL/min

Prothrombin time (PT)

measure of blood coagulation

Normal Prothrombin Time

approximately 12 to 15 seconds

international normalized ratio (INR)

Used to compare a patient's PT with a control sample for a more accurate PT result

normal range for INR

0.8 to 1.2

Partial thromboplastin time (PTT)

an additional lab value used to detect abnormalities in blood clotting

Normal Partial thromboplastin time

25 to 35 seconds

Platelet count

Assess the patient's clotting ability

Normal platelet count

140,000 to 440,000 per mm3 (or μL) of blood.

D-Dimer testing

utilized for the diagnosis of deep vein thrombosis and pulmonary embolism.

Significance of elevated amounts of D-dimer in the bloodstream

Indicates recently degraded blood clots. Additional testing such as CT angiography of the pulmonary arteries may be needed.

liver function tests (LFT)

used to screen for damage to patient's liver. consists of blood tests that measure the levels of various enzymes and proteins in circulating blood.

Alanine Transaminase (ALT), Aspartate

transaminase (AST), and Alkaline phosphate

(ALP)

Liver Function Tests for hepatitis, cirrhosis, blocked bile ducts, or liver malignancy

Normal ALT

7–55 units per liter (U/L)

Normal AST

8–48 units per liter (U/L)

Normal ALP

45–115 units per liter (U/L)

Gamma-glutamyltransferase (GGT)

Used to determine the cause of elevated ALP that can occur in certain liver diseases.

Bilirubin

Type of LFT to determine jaundice (yellowed pigmentation of the skin, orbits, and other mucous membranes).

Normal Bilirubin

0.1–1.2 milligrams per deciliter (mg/dL)

Albumin

LFT to determine chronic liver disease such as cirrhosis.

Normal Albumin

3.5–5.0 grams per deciliter (g/dL)

Total protein (TP)

Type of LFT to determine liver disease

Normal TP

6.3–7.9 grams per deciliter (g/dL) Liver disease may be indicated by a low value

L-Lactate dehydrogenase (LD)

LFT to indicate of liver disease such as hepatitis.

Normal L-Lactate dehydrogenase (LD)

122–222 units per liter (U/L)