Common Radiology Abbreviations and What They Mean

Radiology reports are filled with abbreviations that can make them feel like they're written in a foreign language. "R/O acute process," "S/P surgery," "NAD" - what does it all mean?

This comprehensive guide decodes the most common abbreviations you'll see in CT, MRI, and X-ray reports, organized by category for easy reference.

Clinical History Abbreviations

These abbreviations appear in the "Clinical History" or "Indication" section, explaining why you're getting the scan.

R/O - "Rule Out"

Meaning: The doctor wants to check if you have this condition Example: "R/O appendicitis" = Check if you have appendicitis Important: Does NOT mean you have it - they're looking for it!

S/P - "Status Post"

Meaning: After a previous procedure or event Example: "S/P cholecystectomy" = Had gallbladder removal Common uses:

• S/P surgery - After surgery
• S/P MVA - After motor vehicle accident
• S/P chemo - After chemotherapy

H/O - "History Of"

Meaning: You have a past history of this condition Example: "H/O breast cancer" = Past history of breast cancer

C/O - "Complaining Of" or "Chief Complaint"

Meaning: What symptom brought you in Example: "C/O chest pain" = You're complaining of chest pain

F/U - "Follow-up"

Meaning: Checking on a previous finding Example: "F/U lung nodule" = Monitoring a previously found lung nodule

Normal Findings Abbreviations

WNL - "Within Normal Limits"

Meaning: Everything looks normal Example: "Heart is WNL" = Heart appears healthy Good news! This is what you want to see

NAD - "No Acute Disease" or "No Abnormality Detected"

Meaning: Nothing concerning found Example: "Lungs: NAD" = Lungs look normal Good news!

NL - "Normal"

Meaning: Self-explanatory - normal Example: "Liver: NL" = Normal liver

WNSL - "Within Normal Size and Limits"

Meaning: Size and appearance are normal Example: "Kidneys are WNSL" = Kidneys normal size and appearance

Anatomical Location Abbreviations

Directional Terms

• R = Right
• L = Left
• B/L or BIL = Bilateral (both sides)
• U/L or UNILAT = Unilateral (one side)

Body Regions

• RUQ = Right Upper Quadrant (of abdomen)
• RLQ = Right Lower Quadrant
• LUQ = Left Upper Quadrant
• LLQ = Left Lower Quadrant

Lung Lobes

• RUL = Right Upper Lobe
• RML = Right Middle Lobe
• RLL = Right Lower Lobe
• LUL = Left Upper Lobe
• LLL = Left Lower Lobe

Spine Levels

• C1-C7 = Cervical spine (neck) - 7 vertebrae
• T1-T12 = Thoracic spine (mid-back) - 12 vertebrae
• L1-L5 = Lumbar spine (lower back) - 5 vertebrae
• S1-S5 = Sacral spine (tailbone) - 5 fused vertebrae

Example: "Disc herniation at L4-L5" = Herniated disc between 4th and 5th lumbar vertebrae

Size and Measurement Abbreviations

mm - Millimeters

Context: Measuring nodules, lesions, organs Reference:

• 10mm = 1 centimeter = 0.4 inches
• 25mm = 2.5 cm = 1 inch

Nodule size significance:

• < 6mm = Usually benign, minimal follow-up
• 6-8mm = Low risk, monitoring recommended

• 8mm = Needs further evaluation

cm - Centimeters

Used for: Larger structures (organs, masses) Example: "Liver spans 15 cm" = Normal liver size

AP - Anteroposterior

Meaning: Front-to-back measurement Example: "AP diameter of aorta is 3.5 cm"

Finding Descriptions

Hyperdense / Hypodense (CT)

Hyperdense: Brighter/whiter (bone, blood, calcium, contrast) Hypodense: Darker (fat, fluid, air) Isodense: Same density as surroundings

Example: "Hyperdense lesion consistent with hemorrhage" = Bright spot indicating bleeding

Hyperintense / Hypointense (MRI)

Hyperintense: Brighter signal on MRI Hypointense: Darker signal on MRI Isointense: Same intensity as surroundings

Note: What's "bright" varies by MRI sequence (T1, T2, FLAIR, etc.)

Enhancement

Meaning: Area lights up after contrast dye is given Significance: Shows increased blood flow Example: "Enhancing mass" = Mass has good blood supply (can indicate tumor, infection, or inflammation)

Severity Descriptors

From least to most severe:

1. Trace / Minimal - Barely present
2. Mild - Present but not significant
3. Moderate - Definitely present, noteworthy
4. Severe / Marked - Significant problem

Example: "Mild degenerative changes" vs "Severe degenerative changes"

Common Clinical Abbreviations

CVA - "Cerebrovascular Accident"

Meaning: Stroke Types:

• Ischemic CVA = Stroke from blood clot
• Hemorrhagic CVA = Stroke from bleeding

MI - "Myocardial Infarction"

Meaning: Heart attack

MVA - "Motor Vehicle Accident"

Context: Often seen in trauma imaging Example: "S/P MVA" = After car accident

SOB - "Shortness of Breath"

Example: "SOB with exertion" = Gets short of breath during activity

CP - "Chest Pain"

HA - "Headache"

N/V - "Nausea and Vomiting"

LOC - "Loss of Consciousness"

SZ - "Seizure"

Organ-Specific Abbreviations

Cardiovascular

• CAD = Coronary Artery Disease
• CHF = Congestive Heart Failure
• PE = Pulmonary Embolism (blood clot in lungs)
• DVT = Deep Vein Thrombosis (blood clot in leg)
• AAA = Abdominal Aortic Aneurysm

Respiratory

• COPD = Chronic Obstructive Pulmonary Disease
• PNA = Pneumonia
• PTX = Pneumothorax (collapsed lung)
• SOB = Shortness of Breath
• URI = Upper Respiratory Infection

Gastrointestinal

• GB = Gallbladder
• CBD = Common Bile Duct
• SBO = Small Bowel Obstruction
• LBO = Large Bowel Obstruction
• GI = Gastrointestinal

Genitourinary

• UTI = Urinary Tract Infection
• BPH = Benign Prostatic Hypertrophy (enlarged prostate)
• Hydro = Hydronephrosis (kidney swelling)

Neurological

• MS = Multiple Sclerosis
• ICP = Intracranial Pressure
• SAH = Subarachnoid Hemorrhage (bleeding around brain)
• SDH = Subdural Hematoma (blood clot under skull)

Pathology Descriptors

Acute vs Chronic

Acute: Recent, sudden onset Chronic: Long-standing, persistent Example: "Acute fracture" (new break) vs "Chronic fracture" (old break)

Mass vs Lesion vs Nodule

Mass: General term for abnormal growth or lump Lesion: Any abnormal area (broader term) Nodule: Small, round growth (usually < 3cm)

Cystic vs Solid

Cystic: Fluid-filled Solid: Not fluid-filled Mixed: Has both fluid and solid components

Example: "Cystic mass in kidney" - likely a benign cyst

Technique Abbreviations

IV - "Intravenous"

Context: "CT with IV contrast" = Dye injected through vein

PO - "Per Os" (Latin: By Mouth)

Context: "Oral contrast given" = Dye swallowed

NPO - "Nil Per Os" (Latin: Nothing By Mouth)

Context: "Patient NPO x 6 hours" = No eating/drinking for 6 hours

DWI - "Diffusion Weighted Imaging"

Context: Special MRI sequence for detecting strokes

FLAIR - "Fluid-Attenuated Inversion Recovery"

Context: MRI sequence that suppresses fluid signal

Comparison Terms

Interval

Meaning: Time between scans Example: "Interval development of pneumonia" = Pneumonia developed since last scan

Stable

Meaning: No change from prior scan Example: "Lung nodule is stable" = Same size as before (good news!)

Increased / Decreased

Example: "Pleural effusion has increased" = More fluid around lung than before

New / Resolved

New: Wasn't there before Resolved: Was there before, now gone Example: "Previous infiltrate has resolved" = Pneumonia has cleared up

Phrases That Sound Scary But Often Aren't

"Cannot Exclude"

What it sounds like: You probably have it! What it means: Can't rule it out from images alone Reality: Doesn't mean you have it - may need clinical correlation or more tests

Example: "Cannot exclude small PE" = Based on images alone, can't completely rule out small pulmonary embolism

"Recommend Clinical Correlation"

What it sounds like: Something's wrong! What it means: Radiologist wants findings compared with your symptoms and physical exam Reality: Standard phrase, not necessarily concerning

"Nonspecific"

What it sounds like: The doctor doesn't know! What it means: Finding doesn't point to a specific diagnosis Reality: Many benign conditions look similar on imaging

Example: "Nonspecific white matter changes" - Could be aging, migraines, hypertension, or many other benign causes

"Age-Appropriate" or "Age-Related"

What it means: Normal for your age Example: "Age-appropriate degenerative changes" = Normal wear and tear Good thing! Means it's normal aging

Quick Reference: Abbreviations A-Z

A

• AAA: Abdominal Aortic Aneurysm
• AP: Anteroposterior
• AVM: Arteriovenous Malformation

B

• BIL: Bilateral
• BPH: Benign Prostatic Hypertrophy

C

• C/O: Complaining Of
• CAD: Coronary Artery Disease
• CBD: Common Bile Duct
• CHF: Congestive Heart Failure
• cm: Centimeter
• COPD: Chronic Obstructive Pulmonary Disease
• CP: Chest Pain
• CT: Computed Tomography
• CVA: Cerebrovascular Accident (stroke)

D

• DVT: Deep Vein Thrombosis
• DWI: Diffusion Weighted Imaging

E

• ETT: Endotracheal Tube

F

• F/U: Follow-up
• FLAIR: Fluid-Attenuated Inversion Recovery

G

• GB: Gallbladder
• GI: Gastrointestinal

H

• H/O: History Of
• HA: Headache
• Hydro: Hydronephrosis

I

• ICP: Intracranial Pressure
• IV: Intravenous

L

• LBO: Large Bowel Obstruction
• LOC: Loss of Consciousness
• LLL/LUL: Left Lower/Upper Lobe

M

• MI: Myocardial Infarction
• mm: Millimeter
• MRI: Magnetic Resonance Imaging
• MS: Multiple Sclerosis
• MVA: Motor Vehicle Accident

N

• N/V: Nausea and Vomiting
• NAD: No Abnormality Detected
• NPO: Nothing By Mouth

P

• PE: Pulmonary Embolism
• PNA: Pneumonia
• PO: Per Os (by mouth)
• PTX: Pneumothorax

R

• R/O: Rule Out
• RLL/RML/RUL: Right Lower/Middle/Upper Lobe

S

• S/P: Status Post
• SAH: Subarachnoid Hemorrhage
• SBO: Small Bowel Obstruction
• SDH: Subdural Hematoma
• SOB: Shortness of Breath
• SZ: Seizure

U

• U/L: Unilateral
• URI: Upper Respiratory Infection
• UTI: Urinary Tract Infection

W

• WNL: Within Normal Limits
• WNSL: Within Normal Size and Limits

Tips for Reading Reports with Abbreviations

1. Focus on the IMPRESSION section - This is the summary and uses fewer abbreviations
2. Context is key - Same abbreviation can mean different things in different contexts
3. Ask your doctor - Never hesitate to ask for clarification
4. Use online medical dictionaries - MedlinePlus, Radiopedia are reliable

Still Confused by Your Report?

Even with this guide, radiology reports can be overwhelming. Upload your report to Radily for:

• Personalized explanation of YOUR specific abbreviations
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• Context about what findings mean for your health
• Questions to ask your doctor

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