Imaging Modalities
3D Mammography (Tomosynthesis)
Also called: Tomosynthesis, DBT
A mammogram that takes multiple thin image slices of the breast, improving cancer detection and reducing callbacks.
Patient Education
Glossary of imaging terms.
Plain-language definitions for the words you'll see on your imaging order, your radiology report, and your bill — written by our team to help you understand your care.
142 terms across 5 categories
Most looked-up
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1 termA
8 termsContrast & Safety
ALARA Principle
Also called: As Low As Reasonably Achievable
The radiation-safety principle that radiology should use the lowest dose that still produces a diagnostic image.
Results & Reports
Aneurysm
An abnormal bulge or ballooning in the wall of a blood vessel that can grow and, rarely, rupture.
Anatomy & Procedures
AP, Lateral & Oblique Views
The standard angles X-rays are shot from — front-to-back (AP), side (lateral), and angled (oblique).
Billing, Insurance & Legal
Appeals Process
The formal steps to challenge an insurer's denial of coverage for an imaging exam.
Anatomy & Procedures
Arthrogram
A joint injection of contrast followed by MRI or CT to show subtle tears in cartilage or ligaments.
Results & Reports
Artifact / Motion Artifact
A distortion in the image that isn't real anatomy — often from movement, metal, or the scanner itself.
Billing, Insurance & Legal
Assignment of Benefits (AOB)
Also called: AOB
Authorization that lets your insurer pay the imaging provider directly instead of reimbursing you.
Results & Reports
Avascular Necrosis (AVN)
Also called: AVN, Osteonecrosis
Death of bone tissue from loss of blood supply, most often in the hip, that can lead to joint collapse.
B
7 termsBilling, Insurance & Legal
Balance Billing
Also called: Surprise Billing
When a provider bills you for the difference between their charge and what your insurer paid — restricted in many situations.
Results & Reports
BI-RADS
A standardized 0–6 scoring system used on breast imaging reports.
Anatomy & Procedures
Bilateral vs. Unilateral
Bilateral means both sides are imaged; unilateral means just one side.
Results & Reports
Bone Marrow Edema
Also called: Bone Marrow Lesion
Excess fluid within bone seen on MRI — a sensitive but nonspecific sign of injury, stress, or inflammation.
Imaging Modalities
Bone Scan
Also called: Nuclear Medicine Bone Scan, Skeletal Scintigraphy
A nuclear medicine scan that uses a small injected tracer to highlight areas of active bone turnover across the whole skeleton.
Imaging Modalities
Breast Coil
A specialized antenna that wraps around the breast to sharply boost MRI signal and image detail.
Results & Reports
Bursitis
Inflammation of a bursa — a small fluid-filled sac that cushions tendons and bones near joints.
C
13 termsResults & Reports
Calcification
Calcium deposits within tissue, appearing very bright on CT and X-ray; their pattern offers diagnostic clues.
Anatomy & Procedures
Cervical, Thoracic & Lumbar Spine
The three main regions of the spine: cervical (neck), thoracic (mid-back), and lumbar (lower back).
Results & Reports
Chondral Loss / Cartilage Thinning
Also called: Cartilage Loss
Wearing away of the smooth cartilage that caps the ends of bones in a joint.
Contrast & Safety
Claustrophobia (in MRI)
Anxiety about enclosed spaces — common during MRI and manageable with several options.
Contrast & Safety
Contrast Allergy / Reaction
A reaction to imaging contrast — most often mild, but always something we screen for.
Results & Reports
Contrast Enhancement
Brightening of tissue after contrast is given, indicating blood flow, inflammation, or a breakdown of normal barriers.
Contrast & Safety
Contrast Extravasation
When injected contrast leaks out of the vein into surrounding tissue instead of flowing into the bloodstream.
Billing, Insurance & Legal
Coordination of Benefits (COB)
Also called: COB
The process insurers use to decide who pays first when you're covered by more than one plan.
Billing, Insurance & Legal
Court-Ready Report
A radiology report formatted and detailed enough to support a legal case.
Billing, Insurance & Legal
CPT Code
Also called: Procedure Code
The standardized 5-digit code that identifies exactly which imaging procedure was performed, used for billing.
Imaging Modalities
CT
Also called: CAT Scan, Computed Tomography
A fast X-ray-based scan that creates detailed cross-sectional slices of the body.
Imaging Modalities
CT Angiography
Also called: CTA
A CT scan with IV contrast that highlights arteries and veins.
Imaging Modalities
CT Slices
Also called: Slice Count, Detector Rows
The number of cross-sectional images a CT scanner captures per rotation — more slices mean thinner cuts, faster scans, and sharper 3-D detail.
D
7 termsResults & Reports
Deep Vein Thrombosis (DVT)
Also called: DVT, Blood Clot
A blood clot in a deep vein, usually of the leg, that can be diagnosed with Doppler ultrasound.
Imaging Modalities
DEXA Scan
Also called: DXA, Bone Density Scan
A quick, very low-dose X-ray scan that measures bone density to screen for osteoporosis.
Results & Reports
DICOM
The standard file format for medical images — what gets put on your CD or sent to your provider.
Results & Reports
Disc Bulge
A broad, generalized outward extension of a disc beyond its normal margin — usually milder than a herniation.
Results & Reports
Disc Herniation
Also called: Herniated Disc, Slipped Disc, Ruptured Disc
When the soft center of a spinal disc pushes through its outer ring; subtypes include protrusion, extrusion, and sequestration.
Imaging Modalities
Doppler Ultrasound
An ultrasound technique that shows blood flow direction and speed.
Results & Reports
DWI
Also called: Diffusion-Weighted Imaging
An MRI sequence that detects how freely water moves inside tissue — used to find strokes within minutes and to characterize many tumors.
E
2 termsContrast & Safety
eGFR
Also called: Kidney Function
A blood test that estimates kidney function — sometimes required before IV contrast.
Billing, Insurance & Legal
Explanation of Benefits (EOB)
Also called: EOB
The statement from your insurer explaining what was billed, what they paid, and what you may owe — it is not a bill.
F
9 termsAnatomy & Procedures
Facet Joint
The small paired joints at the back of each spinal level that guide and limit movement.
Results & Reports
Fatty Infiltration / Atrophy
Replacement of normal muscle (or organ tissue) by fat, often signaling chronic disuse, nerve injury, or aging.
Results & Reports
Findings
The detailed section of the report describing what the radiologist saw on every image.
Results & Reports
FLAIR
Also called: Fluid-Attenuated Inversion Recovery
A brain MRI sequence that turns down the bright signal from spinal fluid so small lesions stand out clearly.
Anatomy & Procedures
Flex & Extension MRI
MRI capability to image the spine or joints while you bend forward and arch backward, revealing instability invisible on neutral scans.
Anatomy & Procedures
Flexion & Extension Views
X-rays taken while you bend forward and backward to reveal instability that a neutral image can hide.
Imaging Modalities
Fluoroscopy
Real-time, moving X-ray imaging — often used for swallowing studies and joint injections.
Results & Reports
Follow-Up Imaging
Also called: Surveillance Imaging, Short-Interval Follow-Up
A repeat scan in 3, 6, or 12 months to see whether a finding has stayed stable, shrunk, or grown.
Imaging Modalities
Functional MRI (fMRI)
Also called: fMRI
An MRI that maps brain activity by detecting small changes in blood flow while you perform tasks.
G
3 termsContrast & Safety
Gadolinium
The contrast agent used for most MRI exams that need contrast.
Contrast & Safety
Gadolinium Retention / Deposition
The finding that tiny traces of gadolinium can remain in the body, including the brain, after MRI contrast.
Contrast & Safety
GBCA (Gadolinium-Based Contrast Agent)
Also called: Gadolinium-Based Contrast Agent
The family of MRI contrast agents built around the element gadolinium — the umbrella category for MRI 'dye.'
H
3 termsResults & Reports
Hematoma / Contusion
Also called: Bruise
A collection of blood (hematoma) or a deep bruise (contusion) within tissue, usually from injury.
Imaging Modalities
High-Field MRI
An MRI with a stronger magnet (typically 1.5T or 3T) for the highest-resolution images.
Results & Reports
Hyperintense & Hypointense
MRI descriptors meaning brighter (hyperintense) or darker (hypointense) than surrounding tissue on a given sequence.
I
16 termsBilling, Insurance & Legal
ICD-10 / Diagnosis Code
Also called: Diagnosis Code
The standardized code describing the medical reason (diagnosis or symptom) for your exam.
Anatomy & Procedures
Image-Guided Biopsy
A needle biopsy steered to the target by ultrasound, CT, MRI, or mammography for an accurate tissue sample.
Anatomy & Procedures
Image-Guided Injection
A therapeutic or diagnostic injection placed precisely using ultrasound, fluoroscopy, or CT guidance.
Contrast & Safety
Imaging During Pregnancy
Guidance on which scans are safe in pregnancy — ultrasound and MRI are preferred; radiation and contrast are minimized.
Anatomy & Procedures
Imaging Order (Rx)
Also called: Prescription, Referral
The signed request from your provider that tells us exactly what study to perform and why.
Anatomy & Procedures
Imaging Planes (Axial, Coronal, Sagittal)
The three standard slice orientations used in cross-sectional imaging: axial, coronal, and sagittal.
Anatomy & Procedures
Imaging Protocol
The specific recipe of sequences, contrast, and settings a radiologist selects to answer your clinical question.
Results & Reports
Impression
The bottom-line summary of a radiology report — what the radiologist concludes.
Billing, Insurance & Legal
In-Network vs. Out-of-Network
Whether a provider has a contract with your insurance plan — in-network usually means lower out-of-pocket cost.
Results & Reports
Incidental Finding
Something found on your scan that wasn't the reason it was ordered.
Billing, Insurance & Legal
Independent Medical Examination (IME)
Also called: IME
An evaluation — sometimes including a review of your imaging — by a neutral provider, often requested by an insurer or in litigation.
Imaging Modalities
Interventional Radiology (IR)
Also called: IR
Minimally invasive, image-guided procedures — biopsies, drainages, injections, and vascular treatments — performed through tiny incisions.
Anatomy & Procedures
Intervertebral Disc
Also called: Spinal Disc
The cushioning pad between two vertebrae, with a soft center and a tough outer ring.
Contrast & Safety
Iodinated Contrast
The IV contrast used for most CT exams that need contrast.
Results & Reports
Isointense
An MRI descriptor for a finding that has the same brightness as the tissue around it.
Contrast & Safety
IV Contrast
A liquid injected into a vein during CT or MRI to make blood vessels and certain tissues stand out.
J
1 termResults & Reports
Joint Effusion
Extra fluid within a joint — a common, nonspecific sign of irritation, injury, or arthritis.
L
6 termsAnatomy & Procedures
Labrum
The rim of cartilage that deepens the shoulder and hip sockets and adds stability.
Billing, Insurance & Legal
Letter of Protection (LOP)
An attorney's written promise that imaging bills will be paid from a case settlement.
Billing, Insurance & Legal
Lien
Also called: Medical Lien
An agreement that defers payment for imaging until a personal injury case settles.
Imaging Modalities
Low-Dose CT
A CT protocol tuned to use the lowest radiation dose that still produces a diagnostic image.
Results & Reports
Lung-RADS
A standardized scoring system used on lung cancer screening CT reports.
Results & Reports
Lymphadenopathy
Also called: Enlarged Lymph Nodes
Enlarged lymph nodes — a common reaction to infection or inflammation, and sometimes a sign of malignancy.
M
16 termsImaging Modalities
Mammography
Also called: Mammogram, Digital Mammography
A low-dose X-ray of the breast used to screen for and diagnose breast cancer.
Billing, Insurance & Legal
Medi-Cal
California's Medicaid program, providing health coverage — including imaging — for eligible low-income residents.
Billing, Insurance & Legal
Medical Necessity
The requirement that an exam be clinically appropriate for your condition in order for insurance to cover it.
Billing, Insurance & Legal
Medicare & Medicaid
Government health programs: Medicare mainly for those 65+ and certain disabilities; Medicaid for low-income individuals.
Anatomy & Procedures
Meniscus
The two C-shaped cartilage cushions in each knee that absorb shock and stabilize the joint.
Contrast & Safety
Millisievert (mSv)
Also called: mSv
The unit radiology uses to measure the biological effect of a radiation dose.
Imaging Modalities
MR Angiography (MRA)
Also called: MRA
An MRI technique that maps blood vessels — often without any contrast injection.
Contrast & Safety
MR Safety Classification
Also called: MR-Safe, MR-Conditional, MR-Unsafe
The labeling system that rates whether a device or implant is MR-Safe, MR-Conditional, or MR-Unsafe.
Imaging Modalities
MR Spectroscopy (MRS)
Also called: MRS
An MRI add-on that measures the chemical makeup of tissue rather than just its appearance.
Imaging Modalities
MRCP
Also called: Magnetic Resonance Cholangiopancreatography
A specialized MRI of the bile ducts, gallbladder, and pancreatic duct — no injection or scope required.
Imaging Modalities
MRI
Also called: Magnetic Resonance Imaging
A scan that uses a strong magnet and radio waves — no radiation — to make detailed pictures of soft tissue.
Contrast & Safety
MRI Safety Screening
The questionnaire and review we use to make sure it's safe for you to enter the MRI magnet.
Imaging Modalities
MRI Sedation
Medication that helps anxious or claustrophobic patients relax and stay still during an MRI.
Anatomy & Procedures
MRI Sequence / Series
Each distinct set of MRI images acquired with a particular technique — like T1, T2, or STIR — within a single exam.
Contrast & Safety
MRI-Conditional Pacemaker
A pacemaker or defibrillator designed to undergo MRI safely under specific, controlled conditions.
Results & Reports
Myelopathy
Dysfunction of the spinal cord itself, usually from compression — a more serious finding than radiculopathy.
N
4 termsContrast & Safety
Nephrogenic Systemic Fibrosis (NSF)
Also called: NSF
A rare, serious tissue-scarring disease linked to gadolinium contrast in patients with severe kidney failure.
Anatomy & Procedures
Nerve Block
An image-guided injection of anesthetic (often with steroid) around a nerve to relieve or diagnose pain.
Anatomy & Procedures
Neural Foramen
Also called: Neuroforamen
The bony opening on each side of the spine where a nerve root exits — it can narrow and pinch the nerve.
Results & Reports
Nodule vs. Mass
A size-based distinction: a nodule is small (commonly ≤3 cm), a mass is larger — both describe a discrete lesion.
O
3 termsResults & Reports
Occult Fracture
Also called: Radiographically Occult Fracture
A fracture not visible on X-ray but detectable on MRI or CT.
Imaging Modalities
Open MRI
An MRI scanner with open sides — easier for patients who are claustrophobic or larger-bodied.
Results & Reports
Osteophyte (Bone Spur)
Also called: Bone Spur
A bony outgrowth that forms at the edges of joints or vertebrae as part of arthritis and aging.
P
9 termsResults & Reports
Partial vs. Full-Thickness Tear
A partial tear involves only part of a tendon or ligament; a full-thickness tear goes all the way through.
Anatomy & Procedures
Patient Positioning (Prone vs. Supine)
How you're placed for the scan — supine is face-up, prone is face-down — chosen to optimize the images.
Billing, Insurance & Legal
Peer Review / Utilization Review
Insurer review of whether a requested or completed exam meets coverage and appropriateness criteria.
Billing, Insurance & Legal
Personal Injury Protection (PIP)
Also called: PIP, No-Fault
Auto-insurance coverage that pays medical costs, including imaging, after a car accident regardless of fault.
Imaging Modalities
PET / PET-CT
Also called: Positron Emission Tomography
A nuclear medicine scan that maps metabolic activity — commonly used in cancer staging — usually fused with CT.
Contrast & Safety
Pre-Medication Protocol
Also called: Premedication
A regimen of steroids and antihistamines taken before contrast to reduce the risk of an allergic-type reaction.
Billing, Insurance & Legal
Predetermination / Precertification
Also called: Precertification, Precert
An insurer's advance review confirming whether a planned exam will be covered before it's performed.
Billing, Insurance & Legal
Prior Authorization
Also called: Pre-Auth, PA
Insurance approval required before certain scans — most MRIs and CTs.
Results & Reports
Pulmonary Embolism (PE)
Also called: PE
A blockage in a lung artery, usually from a clot that traveled from a leg vein — diagnosed with CT angiography.
R
3 termsResults & Reports
Radiculopathy
Also called: Pinched Nerve, Sciatica
Symptoms — radiating pain, numbness, or weakness — caused by compression or irritation of a spinal nerve root.
Results & Reports
Radiology Report
The written interpretation of your scan by a board-certified radiologist.
Anatomy & Procedures
Rotator Cuff
The group of four shoulder muscles and tendons that stabilize the joint and lift the arm.
S
18 termsAnatomy & Procedures
Screening vs. Diagnostic
Screening exams look for disease in people without symptoms; diagnostic exams evaluate a specific problem.
Billing, Insurance & Legal
Self-Pay
Also called: Cash Price
Paying out-of-pocket at our discounted cash price instead of using insurance.
Results & Reports
Signal Void
An area on MRI that appears completely black because it produces little or no signal.
Anatomy & Procedures
Slice Thickness & Field of View
Also called: FOV
Two settings that control image detail: how thin each slice is and how much of the body each image covers.
Results & Reports
Soft Tissue Edema
Fluid or swelling within muscles, fat, or other soft tissues, seen as bright signal on fluid-sensitive imaging.
Contrast & Safety
Specific Absorption Rate (SAR)
Also called: SAR
A measure of how much radio-frequency energy the body absorbs during MRI, monitored to prevent tissue heating.
Imaging Modalities
SPECT / SPECT-CT
Also called: Single-Photon Emission CT
A nuclear medicine scan that builds 3D images of tracer uptake, often fused with CT for precise localization.
Anatomy & Procedures
Spinal Canal
The central bony tunnel that protects the spinal cord and nerves — narrowing here is called central stenosis.
Results & Reports
Spinal Stenosis
Narrowing of the spinal canal (central) or nerve-exit openings (foraminal) that can compress the cord or nerves.
Results & Reports
Spondylolisthesis
When one vertebra slips forward (or backward) relative to the one below it.
Results & Reports
Spondylosis
Also called: Spinal Degeneration, Spinal Osteoarthritis
A general term for age-related wear-and-tear changes of the spine, including discs, joints, and bone spurs.
Results & Reports
STAT Read
Also called: Stat Interpretation, Urgent Read
An urgent radiology interpretation — typically delivered within hours, sometimes under an hour — when the clinical situation needs immediate decision-making.
Results & Reports
STIR
Also called: Short Tau Inversion Recovery
An MRI sequence with the fat signal suppressed — used to detect bone bruises, stress fractures, and soft-tissue edema.
Results & Reports
Stress Fracture / Stress Reaction
An overuse injury where repetitive load creates bone swelling (stress reaction) or a small crack (stress fracture).
Results & Reports
Sub-Specialty Read
Also called: Fellowship-Trained Read
A radiology interpretation by a fellowship-trained sub-specialist — neuro, MSK, body, or cardiothoracic — for added expertise on complex cases.
Results & Reports
Subchondral Change
Changes in the bone just beneath joint cartilage — cysts, sclerosis, or edema — that accompany arthritis.
Billing, Insurance & Legal
Subpoena
A legal request for records or images — handled by our records team.
Results & Reports
Synovitis
Inflammation of the synovium, the lining of a joint — a source of pain, swelling, and effusion.
T
6 termsResults & Reports
T1-weighted
A type of MRI image where fat looks bright and fluid looks dark.
Results & Reports
T2-weighted
A type of MRI image where fluid (edema, CSF) looks bright.
Billing, Insurance & Legal
Technical & Professional Components
Also called: TC/PC, Global Billing
Imaging bills split into the technical part (the scan itself) and the professional part (the radiologist's read); together they're 'global.'
Results & Reports
Tendinopathy (Tendinosis vs. Tendinitis)
Also called: Tendinosis, Tendinitis
An umbrella term for a painful, abnormal tendon; tendinitis implies active inflammation, tendinosis implies chronic degeneration.
Anatomy & Procedures
Tendon vs. Ligament
A tendon connects muscle to bone; a ligament connects bone to bone.
Imaging Modalities
Tesla (T)
The unit that measures how strong an MRI magnet is — higher Tesla generally means sharper images in less time.
U
2 termsImaging Modalities
Ultrasound
Also called: Sonography, US
A radiation-free scan that uses sound waves to image organs, vessels, and soft tissue in real time.
Imaging Modalities
Upright / Weight-Bearing MRI
Also called: Standing MRI, Positional MRI
An MRI performed while you sit, stand, or bear weight so the spine and joints are imaged in the position that actually causes symptoms.
W
4 termsAnatomy & Procedures
Weight-Bearing Views
Also called: Standing Views
X-rays taken while you stand and put weight on the joint, showing how it behaves under real load.
Imaging Modalities
Wide-Bore MRI
A closed MRI with a wider, shorter tunnel — more comfortable for larger or claustrophobic patients while keeping high-field image quality.
Anatomy & Procedures
With and Without Contrast
A scan performed twice — once without contrast and once after contrast is injected.
Billing, Insurance & Legal
Workers' Compensation Imaging
Also called: Workers' Comp, Work Comp
Imaging for a work-related injury, billed to the employer's workers' compensation insurer under its own rules.
X
1 termImaging Modalities
X-Ray
Also called: Radiograph, Plain Film
A quick, low-radiation image that's best for bones, lungs, and foreign bodies.
Still have a question about your order or report?
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