Why Cross-Training Matters for the ARDMS Registry
The ARDMS registry exams don't test ultrasound in isolation. Questions frequently reference other imaging modalities and how they relate to sonographic findings. You'll encounter scenarios where a CT finding triggers an ultrasound follow-up, an MRI confirms what you saw on US, or a nuclear medicine study provides functional data that complements your anatomic scan.
This module teaches you to recognize how imaging modalities work together in clinical practice β the same way the registry tests it. No practice questions here, just the knowledge foundation you need to understand the cross-references.
What You'll Learn
Modality Fundamentals
How CT, MRI, Nuclear Medicine, Mammography, and X-ray actually work β enough to understand registry questions, not to become a radiologist.
Clinical Pathways
Real-world diagnostic workflows: when US leads to CT, when MRI follows US, when nuclear medicine triggers echo β and why.
Side-by-Side Comparisons
How the same pathology looks on US vs CT vs MRI. Pattern recognition across modalities builds deeper understanding.
Registry Keywords
Specific terms and phrases from other modalities that appear on ARDMS exams. Know them before test day.
Case Studies
Multi-modality workups showing the complete diagnostic journey β from initial presentation through imaging to diagnosis.
Medical Terminology
Roots, prefixes, and suffixes that appear across all imaging reports. Decode any term on the registry.
Imaging Modalities at a Glance
Each modality uses different physics to create images. Understanding the basics helps you interpret registry questions that reference other studies.
Ultrasound (US)
Physics: Sound waves (2-18 MHz) reflected at tissue interfaces. Real-time, portable, no radiation. Operator-dependent.
Best for: Soft tissue, fluid vs solid, real-time motion, Doppler flow, fetal imaging, bedside/POCUS.
Limitations: Body habitus, bowel gas, operator skill, limited by bone/air interfaces.
Your specialtyComputed Tomography (CT)
Physics: X-ray tube rotates around patient; detectors measure attenuation. Hounsfield units (HU) quantify density.
Best for: Trauma, lung, bone, hemorrhage, vascular (CTA), rapid whole-body survey. Excellent spatial resolution.
Limitations: Ionizing radiation, IV contrast risks (allergy, renal), limited soft tissue contrast vs MRI.
Ionizing radiationMagnetic Resonance Imaging (MRI)
Physics: Strong magnetic field aligns hydrogen protons; RF pulses and gradient fields create signal. T1, T2, FLAIR, DWI sequences.
Best for: Soft tissue contrast (brain, spine, joints, liver characterization), no radiation. Gold standard for many pathologies.
Limitations: Slow, expensive, claustrophobia, contraindicated with some implants, gadolinium risks (NSF).
No radiationNuclear Medicine (NM)
Physics: Radiotracer injected IV; gamma camera detects emitted photons. Shows function not just anatomy. SPECT and PET.
Best for: Thyroid (I-123), cardiac perfusion (Tc-99m), bone mets (Tc-99m MDP), hepatobiliary (HIDA), PE (V/Q), PET-CT for cancer staging.
Limitations: Radiation dose, poor spatial resolution, limited anatomy, pregnancy contraindicated.
Functional imagingMammography
Physics: Low-energy X-rays (25-35 kVp) through compressed breast. Digital (FFDM) and tomosynthesis (DBT, 3D).
Best for: Breast cancer screening, calcifications (micro/macro), architectural distortion. BI-RADS classification.
Limitations: Dense breast tissue reduces sensitivity, radiation, compression discomfort, lower sensitivity in young women.
Screening standardX-ray (Radiography)
Physics: Single X-ray beam through body onto detector. 2D projection of 3D anatomy. Density: airβfatβsoft tissueβboneβmetal.
Best for: Fractures, pneumonia, CHF (cardiomegaly, pulmonary edema), foreign bodies, bowel obstruction, lines/tubes.
Limitations: 2D only, limited soft tissue detail, superimposition of structures, radiation.
First-line imagingKey Physics Comparisons for the Registry
| Property | US | CT | MRI | Nuclear |
|---|---|---|---|---|
| Energy source | Sound waves | X-rays | RF + magnetic field | Radiotracer (Ξ³-rays) |
| Radiation | None (ALARA still applies β thermal/mechanical) | Yes (ionizing) | None | Yes (ionizing) |
| Contrast agent | Microbubbles (Definity, Lumason) | Iodinated IV | Gadolinium IV | Radiotracer IV |
| Spatial resolution | Good (axial 0.5-1mm) | Excellent (<1mm) | Good (1-2mm) | Poor (6-10mm) |
| Temporal resolution | Excellent (real-time) | Good (gated) | Poor (seconds) | Poor (minutes) |
| Soft tissue contrast | Moderate | Moderate | Excellent | N/A (functional) |
| Pregnancy safe? | Yes (diagnostic levels) | No (avoid) | Relative (no gadolinium) | No |
| Cost | Low | Moderate | High | High |
| Portability | Excellent (bedside) | None (fixed) | None (fixed) | None (fixed) |
Cardiac Workup Pathways
π« Chest Pain / Suspected CAD
Registry connection: A nuclear stress test showing a "reversible perfusion defect" = ischemia. This patient may then get a stress echo to assess wall motion. A "fixed defect" = old infarct/scar. Echo would show regional wall motion abnormality (akinesis/dyskinesis) in the corresponding territory.
π« Heart Failure Evaluation
Registry connection: CXR shows "cephalization of vessels" and "Kerley B lines" = pulmonary edema from CHF. Echo quantifies LVEF (HFrEF β€40%, HFpEF β₯50%). Cardiac MRI with late gadolinium enhancement (LGE) shows fibrosis/scar pattern β subendocardial = ischemic, mid-wall = non-ischemic (myocarditis, HCM). MUGA scan gives most reproducible EF (used for chemo monitoring).
π« Valvular Heart Disease
Registry connection: TTE is the first-line for all valve disease. TEE provides higher-resolution views (especially MV, LA appendage, prosthetic valves). Cardiac CT measures aortic annulus dimensions for TAVR sizing β you may see "annular calcium" or "CT-derived annulus" on the registry. Cardiac cath provides invasive hemodynamic confirmation when echo and symptoms are discordant.
π« Pulmonary Embolism
Registry connection: CTPA is gold standard for PE diagnosis. Echo in massive PE shows RV dilation, septal bowing, McConnell sign (RV free wall akinesis with apical sparing), and elevated RVSP. The venous duplex is ordered to find the DVT source. V/Q scan (nuclear) is alternative when CTA is contraindicated β "high probability V/Q" = mismatched perfusion defect.
Abdominal / Hepatobiliary Pathways
π« Liver Mass Workup
Registry connection: US often detects the mass first. CT/MRI characterizes it: hemangioma shows peripheral nodular enhancement filling in centripetally. HCC shows arterial enhancement + portal venous washout + enhancing capsule (LI-RADS criteria). FNH has a central scar that enhances on delayed phase. "Washout" and "arterial enhancement" are registry keywords.
π« RUQ Pain (Gallbladder)
Registry connection: US is first-line for RUQ pain (stones, wall thickening, Murphy sign, CBD dilation). HIDA scan (nuclear, Tc-99m DISIDA) shows non-visualization of gallbladder = acute cholecystitis (cystic duct obstruction). MRCP (MRI) is non-invasive to evaluate CBD/pancreatic duct without contrast or radiation. ERCP is both diagnostic and therapeutic (can remove stones, place stents).
π« Renal Mass
Registry connection: US identifies simple cyst (Bosniak I: anechoic, thin wall, posterior enhancement) vs complex/solid. CT Bosniak classification uses enhancement (>20 HU change): I = simple cyst, II = minimally complex, IIF = follow-up, III = indeterminate (surgery considered), IV = clearly malignant. RCC on CT shows heterogeneous enhancement. "Hounsfield units" and "enhancement" are registry keywords.
π« Aortic Aneurysm Surveillance
Registry connection: US is the screening and surveillance tool for AAA (β₯3 cm). CTA provides exact dimensions, branch vessel anatomy, and planning for endovascular repair (EVAR). US measures AP diameter outer-to-outer. CT measures in multiple planes. Repair threshold: β₯5.5 cm or rapid growth >0.5 cm/6 months.
OB/GYN Pathways
π€° First Trimester Bleeding
Registry connection: TV US is the primary imaging for first-trimester bleeding. Discriminatory hCG level (~1500-2000 mIU/mL): above this, IUP should be visible on TV US. If no IUP seen β ectopic pregnancy workup. MRI may be used for unusual ectopic implantation sites (c-section scar pregnancy, cervical ectopic).
π©Ί Breast Mass Workup
Registry connection: Mammography detects calcifications that US cannot see. US differentiates cyst from solid and guides biopsy. Breast MRI has highest sensitivity but lowest specificity β used for high-risk screening (BRCA+), pre-operative extent assessment, and implant evaluation. BI-RADS classification applies to all breast imaging. "Architectural distortion," "spiculated mass," and "grouped microcalcifications" are registry keywords from mammography.
Vascular & MSK Pathways
𦡠DVT / PE Workup
Registry connection: Compression US is first-line for DVT. Non-compressibility = positive DVT. CTPA is gold standard for PE. CT venography can be done in the same sitting as CTPA β the contrast is already in the veins. MR venography is an alternative for contrast-allergic patients.
𦴠Rotator Cuff Tear
Registry connection: US has sensitivity comparable to MRI for full-thickness rotator cuff tears (>90% in experienced hands). US advantage: dynamic evaluation, contralateral comparison, guided injection, lower cost. MRI advantage: full field of view, bone marrow, labrum, better for partial tears and surgical planning. "Full-thickness tear" vs "partial-thickness tear" vs "tendinosis" are critical distinctions on the registry.
How the Same Pathology Looks Across Modalities
Understanding appearance differences helps you answer registry questions that describe findings on other studies and ask what you'd expect on ultrasound.
Liver Hemangioma
π On Ultrasound
Hyperechoic, well-circumscribed, homogeneous. Posterior acoustic enhancement. No internal vascularity on color Doppler. Typical location: right lobe, posterior.
US appearanceπ« On CT
Hypodense on non-contrast. Peripheral nodular enhancement on arterial phase with progressive centripetal fill-in on portal/delayed phases. Complete fill-in on delayed = diagnostic.
CT appearance𧲠On MRI
Very bright on T2 ("light bulb sign"). T1 hypointense. Same peripheral nodular enhancement pattern as CT. MRI is confirmatory when US is atypical.
MRI appearanceHepatocellular Carcinoma (HCC)
π On Ultrasound
Variable echogenicity (hypo/iso/hyperechoic). Heterogeneous mass in cirrhotic liver. May show "halo" sign (hypoechoic rim = pseudocapsule). Hepatic vein/portal vein invasion.
US appearanceπ« On CT
Arterial enhancement (hypervascular) + portal venous washout + enhancing capsule = LI-RADS 5 (definite HCC). No biopsy needed if criteria met in at-risk patient.
CT appearance𧲠On MRI
Same enhancement pattern as CT. MRI more sensitive for small lesions. Diffusion restriction on DWI. Eovist (hepatocyte-specific contrast) shows hypointense on hepatobiliary phase = diagnostic.
MRI appearanceGallstones vs Choledocholithiasis
π On Ultrasound
GB stones: echogenic foci + posterior shadow + gravity-dependent. CBD stones: dilated CBD (>6mm) Β± visible stone. US sensitivity for CBD stones is only 50-70%.
US appearance𧲠On MRCP
CBD stones appear as dark filling defects within bright bile on T2. MRCP sensitivity >95% for CBD stones. Non-invasive, no contrast needed.
MRI appearanceβ’οΈ On HIDA
Non-visualization of gallbladder at 4 hours (with CCK/morphine augmentation) = acute cholecystitis. GB ejection fraction <35% = biliary dyskinesia.
Nuclear appearanceRenal Cell Carcinoma
π On Ultrasound
Solid heterogeneous renal mass. May be iso/hyper/hypoechoic. Internal vascularity on color Doppler. Check for IVC extension (tumor thrombus).
US appearanceπ« On CT
Enhancing solid mass (>20 HU enhancement). Heterogeneous. May contain calcification, necrosis. CT defines TNM staging, IVC involvement, lymph nodes, mets.
CT appearance𧲠On MRI
T2 hyperintense, enhancing. MRI better for characterizing indeterminate renal lesions (hemorrhagic cyst vs solid). DWI restriction in malignancy.
MRI appearanceAortic Aneurysm
π On Ultrasound
AP diameter measured outer wall to outer wall. Mural thrombus appears echogenic. Cannot reliably see suprarenal extent or iliac involvement.
US appearanceπ« On CTA
Complete visualization: exact dimensions in all planes, branch vessel anatomy, iliac extension, mural thrombus, signs of impending rupture (crescent sign, draped aorta).
CT appearanceCarotid Stenosis
π On Duplex US
B-mode plaque characterization + Doppler velocities (PSV, EDV, ICA/CCA ratio). SRU consensus criteria for stenosis grading. Dynamic, real-time, no contrast.
US appearanceπ« On CTA
Luminal narrowing measured by NASCET criteria (1 - residual lumen / distal ICA Γ 100). Calcified vs soft plaque. Visualization of intracranial circulation.
CT appearance𧲠On MRA
Time-of-flight (TOF) or contrast-enhanced MRA. Can overestimate stenosis (flow gap artifact). Used when CTA contraindicated or for intracranial vessels.
MRI appearanceBreast Masses
π On Ultrasound
Cyst vs solid differentiation. Benign: oval, parallel, circumscribed, no vascularity. Suspicious: irregular, taller-than-wide, angular margins, posterior shadowing.
US appearanceπ©» On Mammography
Mass characteristics: shape, margins, density. Calcifications: benign (coarse, popcorn, eggshell) vs suspicious (fine pleomorphic, linear branching). Architectural distortion.
Mammo appearance𧲠On Breast MRI
Enhancement kinetics: type I (persistent = benign), type II (plateau = indeterminate), type III (washout = suspicious). Highest sensitivity for invasive cancer.
MRI appearanceThyroid Nodules
π On Ultrasound
TI-RADS scoring: composition, echogenicity, shape, margin, echogenic foci. Suspicious: solid hypoechoic, taller-than-wide, irregular margins, microcalcifications.
US appearanceβ’οΈ On Nuclear (I-123)
"Hot" nodule (hyperfunctioning) = almost always benign. "Cold" nodule (non-functioning) = higher cancer risk β needs FNA. Thyroid scan determines function.
Nuclear appearanceMulti-Modality Case Studies
Each case traces the complete diagnostic journey, showing how different imaging modalities complement each other.
Case 1: 65-year-old Male β Chest Pain on Exertion
PMH: HTN, DM, smoker. Presenting complaint: substernal chest pressure with exercise Γ 3 weeks.
Step 1: Initial Workup
EKG: normal sinus rhythm, no acute ST changes. Troponin: negative Γ 2. CXR: mild cardiomegaly, no pulmonary edema.
Step 2: Nuclear Stress Test (Tc-99m Sestamibi)
Exercise treadmill to 85% MPHR. Nuclear perfusion imaging shows reversible perfusion defect in the anteroseptal and apical segments.
Step 3: Stress Echocardiogram (Follow-up)
Rest: normal wall motion, LVEF 58%. Peak stress: new hypokinesis of the anterior wall and anteroseptal segments (LAD territory). Basal inferior wall hyperdynamic (compensatory).
Step 4: Coronary CTA (or Cath)
CTA reveals 80% stenosis of the mid-LAD with mixed plaque (calcified + soft). Referred for cardiac catheterization and stent placement.
Case 2: 52-year-old Female β Incidental Liver Lesion
PMH: healthy. CT abdomen for unrelated reason reveals 3 cm liver lesion. Referred for ultrasound correlation.
Step 1: CT Finding
Contrast-enhanced CT shows a 3 cm well-circumscribed lesion in the right hepatic lobe, segment VI. Peripheral nodular enhancement on arterial phase with progressive centripetal fill-in on portal venous and delayed phases.
Step 2: Liver Ultrasound
US shows a well-circumscribed, hyperechoic, homogeneous mass in segment VI with posterior acoustic enhancement. No internal vascularity on color Doppler.
Step 3: MRI Confirmation (if atypical)
If the US appearance were atypical (e.g., hypoechoic in a fatty liver), MRI would be ordered. Hemangioma on MRI: very bright T2 ("light bulb sign"), same enhancement pattern as CT.
Case 3: 28-year-old Female β Pelvic Pain + Positive hCG
PMH: prior ectopic pregnancy, IUD removed 3 months ago. Ξ²-hCG: 2,800 mIU/mL.
Step 1: Transvaginal Ultrasound
No intrauterine pregnancy (IUP) seen. Endometrial stripe measures 12 mm (thickened, "pseudodecidual reaction"). Right adnexa: 2 cm complex mass with a hyperechoic ring ("tubal ring sign"). Small amount of free fluid in the cul-de-sac.
Step 2: Clinical Decision
With hCG >2,000 (above discriminatory level for TV US) and no IUP, this is an ectopic pregnancy. Patient is hemodynamically stable β medical management with methotrexate is considered.
Step 3: MRI (if C-section scar ectopic suspected)
In unusual locations (c-section scar, cervical, interstitial), MRI helps delineate the relationship of the ectopic to the myometrium and surrounding structures for surgical planning.
Case 4: 70-year-old Male β Carotid Bruit + TIA
PMH: HTN, hyperlipidemia. Episode of right arm weakness and speech difficulty lasting 20 minutes (TIA).
Step 1: Carotid Duplex Ultrasound
Left ICA: heterogeneous plaque at the bulb with ulceration. PSV 285 cm/s, EDV 122 cm/s, ICA/CCA ratio 4.8. Classified as 70-99% stenosis per SRU consensus criteria.
Step 2: CTA Head/Neck
Confirms severe left ICA stenosis at 78% by NASCET criteria. No intracranial occlusion. Good collateral flow via Circle of Willis.
Step 3: Surgical Decision
Symptomatic stenosis >70% = carotid endarterectomy (CEA) or carotid artery stenting (CAS) recommended per guidelines. Post-operative duplex surveillance at 30 days, 6 months, then annually.
Case 5: 45-year-old Female β Breast Mass on Screening Mammogram
No symptoms. Routine screening mammogram (age-appropriate). BIRADS 0 β incomplete, needs additional imaging.
Step 1: Screening Mammogram
A 1.5 cm oval mass with partially obscured margins identified in the upper outer quadrant of the right breast. No calcifications. Dense breast tissue (ACR density C).
Step 2: Targeted Breast Ultrasound
Correlating mass at 10 o'clock, 5 cm from nipple: 1.4 cm oval, parallel, circumscribed, hypoechoic solid mass with no posterior features. No internal vascularity.
Step 3: If Suspicious Features
If the mass were taller-than-wide, irregular, or had posterior shadowing, it would be BI-RADS 4 (suspicious). US-guided core needle biopsy would be performed. If calcifications are the concern and not visible on US, stereotactic mammographic biopsy is used instead.
Registry Keywords from Other Modalities
These terms from CT, MRI, Nuclear Medicine, and Mammography appear on ARDMS exams. Know what they mean and how they connect to ultrasound findings.
CT Keywords
| Term | Meaning | US Connection |
|---|---|---|
| Hounsfield Units (HU) | CT density measurement. Water=0, air=-1000, bone=+1000, fat=-100, soft tissue=+40-60 | US uses echogenicity instead (anechoic, hypo, iso, hyperechoic) |
| Arterial enhancement | Lesion becomes bright on arterial phase CT = hypervascular | On US: increased vascularity on color Doppler |
| Portal venous washout | Lesion becomes darker than liver on portal phase = suspicious for HCC | US: cannot directly assess enhancement, but can see flow characteristics |
| LI-RADS | Liver Imaging Reporting and Data System for HCC in at-risk patients | US LI-RADS (CEUS) is a separate scoring system using contrast-enhanced US |
| Bosniak classification | CT classification of renal cysts (I-IV) based on septations, enhancement, calcification | US can identify simple cysts (Bosniak I) but CT needed for enhancement assessment |
| NASCET criteria | North American method to measure carotid stenosis on CTA: (1βresidual/distal ICA)Γ100 | US uses velocity criteria (SRU consensus) which correlate with NASCET percentages |
| Ground glass opacity | Hazy lung opacity on CT (inflammation, infection, hemorrhage) | US: B-lines (lung ultrasound) correspond to interstitial edema, correlate with CT GGO in some settings |
| Crescent sign | High-attenuation crescent in AAA wall = acute/impending rupture | US: may see echogenic focus in mural thrombus, but CT is definitive for rupture signs |
MRI Keywords
| Term | Meaning | US Connection |
|---|---|---|
| T1-weighted | Fat = bright, fluid = dark. Good for anatomy. "T1 = fat is fine" | US: fat is hyperechoic (similar concept) |
| T2-weighted | Fluid = bright, muscle = dark. Good for pathology/edema. "T2 = water is white" | US: fluid is anechoic (black). Opposite brightness convention |
| DWI (diffusion-weighted) | Restricted diffusion = bright. Indicates high cellularity (tumor, abscess, acute stroke) | No direct US equivalent, but abscess on US is complex fluid collection |
| Late gadolinium enhancement (LGE) | Bright areas on delayed cardiac MRI = fibrosis/scar. Pattern distinguishes ischemic vs non-ischemic | Echo: regional wall motion abnormality corresponds to LGE distribution. Strain imaging (GLS) correlates with fibrosis |
| Light bulb sign | Very bright T2 signal in liver hemangioma = diagnostic | US: hemangioma is hyperechoic, homogeneous. Different appearance but same diagnosis |
| Central scar | FNH shows a central scar that enhances on delayed phase | US: FNH is subtle, near-isoechoic, may see central scar as hyperechoic line |
| NSF (nephrogenic systemic fibrosis) | Rare gadolinium contrast reaction in patients with severe renal failure (GFR <30) | US contrast (microbubbles) does NOT cause NSF β advantage of CEUS in renal failure patients |
Nuclear Medicine Keywords
| Term | Meaning | US Connection |
|---|---|---|
| Reversible perfusion defect | Area of reduced perfusion on stress that normalizes at rest = ischemia | Stress echo: corresponding new WMA at peak stress that wasn't present at rest |
| Fixed perfusion defect | Area of reduced perfusion on both stress and rest = old infarct/scar | Echo: resting WMA (akinesis/thinning) in the same territory = chronic MI |
| MUGA scan | Nuclear ventriculography β most reproducible LVEF measurement | Echo EF by Simpson biplane is the standard. MUGA used when echo windows are poor or for chemo monitoring |
| HIDA non-visualization | Gallbladder doesn't fill with radiotracer at 4 hours = acute cholecystitis | US: stones + thick wall + Murphy sign + pericholecystic fluid = cholecystitis. HIDA confirms when US is equivocal |
| Hot nodule (thyroid) | Hyperfunctioning thyroid nodule on I-123 scan β almost always benign | US cannot determine function. A suspicious-appearing nodule on US that is "hot" on nuclear may NOT need biopsy |
| Cold nodule (thyroid) | Non-functioning thyroid nodule β higher cancer risk, needs FNA | US-guided FNA is performed on suspicious cold nodules. TI-RADS helps decide which need biopsy |
| V/Q mismatch | Ventilation-perfusion scan: perfusion defect without ventilation defect = high probability PE | Echo in PE: RV dilation, TR, McConnell sign. Venous duplex may show DVT source |
| Bone scan (Tc-99m MDP) | Increased uptake = osteoblastic activity (metastasis, fracture, infection, Paget disease) | US role: guide biopsy of soft tissue component, assess associated soft tissue mass |
Mammography Keywords
| Term | Meaning | US Connection |
|---|---|---|
| BI-RADS | Breast Imaging Reporting standardized classification (0-6) | US uses the same BI-RADS categories. Know what each number means |
| Architectural distortion | Distortion of breast tissue without a visible mass β suspicious for cancer or radial scar | US may show irregular hypoechoic area at the site, or may be occult on US (mammo-only finding) |
| Microcalcifications | Tiny calcifications that may indicate DCIS. Fine pleomorphic or linear branching = suspicious | US generally CANNOT see microcalcifications. If the lesion is calcification-only, stereotactic biopsy (not US-guided) is needed |
| Spiculated mass | Mass with radiating lines from margin = highly suspicious for malignancy | US: corresponding irregular, hypoechoic, non-parallel mass with angular margins and posterior shadowing |
| ACR density | A (fatty) β D (extremely dense). Dense breasts reduce mammo sensitivity | US is more sensitive in dense breasts (ACR C-D). Supplemental screening US recommended for dense-breast patients |
| Skin thickening / trabecular thickening | May indicate inflammatory breast cancer or lymphatic obstruction | US: skin thickening >2mm, edema pattern, enlarged axillary lymph nodes |
Medical Terminology for the Registry
Understanding word roots, prefixes, and suffixes lets you decode unfamiliar terms on the exam. If you can break apart a word, you can figure out its meaning even if you've never seen it before.
Common Prefixes
| Prefix | Meaning | Example |
|---|---|---|
| hyper- | Excessive, above normal | Hyperechoic (brighter than surrounding tissue), hypertension, hyperthyroid |
| hypo- | Deficient, below normal | Hypoechoic (darker than surrounding tissue), hypotension, hypothyroid |
| an-/a- | Without, absence of | Anechoic (no echoes = black), anemia, amenorrhea, anencephaly |
| iso- | Equal, same | Isoechoic (same echogenicity as reference tissue) |
| poly- | Many, excessive | Polyhydramnios (too much amniotic fluid), polycystic, polyuria |
| oligo- | Few, deficient | Oligohydramnios (too little fluid), oliguria |
| dys- | Difficult, abnormal | Dysplasia (abnormal development), dyspnea, dysuria |
| tachy- | Fast | Tachycardia (fast heart rate >100 bpm) |
| brady- | Slow | Bradycardia (slow heart rate <60 bpm) |
| peri- | Around | Pericardial (around the heart), perinephric, periportal |
| retro- | Behind, backward | Retroperitoneal (behind peritoneum), retroplacental |
| endo- | Within | Endometrium (inner lining), endocardium, endovascular |
| echo- | Reflected sound | Echogenic (producing echoes), echolucent (same as anechoic) |
| sono- | Sound | Sonography, sonolucent, sonographer |
| hemo-/hemato- | Blood | Hematoma (blood collection), hemorrhage, hemolysis |
| hepato- | Liver | Hepatomegaly (enlarged liver), hepatocellular, hepatopetal (toward liver) |
| nephro-/reno- | Kidney | Nephromegaly, nephrolithiasis (kidney stones), renovascular |
| cholecyst- | Gallbladder | Cholecystitis (GB inflammation), cholecystectomy (GB removal) |
| choledocho- | Common bile duct | Choledocholithiasis (CBD stone), choledochal (relating to CBD) |
Common Suffixes
| Suffix | Meaning | Example |
|---|---|---|
| -itis | Inflammation | Cholecystitis, appendicitis, pancreatitis, endocarditis |
| -osis | Condition, abnormal state | Stenosis (narrowing), cirrhosis, thrombosis, fibrosis |
| -ectasis | Dilation, expansion | Bronchiectasis, pyelectasis (dilated renal pelvis), atelectasis |
| -megaly | Enlargement | Hepatomegaly, splenomegaly, cardiomegaly |
| -pathy | Disease | Cardiomyopathy, nephropathy, neuropathy |
| -oma | Tumor/mass | Hemangioma, hepatoma (HCC), carcinoma, fibroma |
| -lithiasis | Stones | Cholelithiasis (gallstones), nephrolithiasis (kidney stones) |
| -ectomy | Surgical removal | Cholecystectomy, nephrectomy, appendectomy |
| -plasty | Surgical repair | Angioplasty, valvuloplasty |
| -scopy/-graphy | Visual examination / recording | Echocardiography, sonography, mammography, angiography |
| -penia | Deficiency | Thrombocytopenia (low platelets), leukopenia |
| -stasis | Stopping, standing still | Hemostasis (stopping bleeding), cholestasis (bile stasis) |
| -emesis | Vomiting | Hematemesis (vomiting blood), hyperemesis |
Body System Roots
| Root | Meaning | Example in Sonography |
|---|---|---|
| cardi/o | Heart | Echocardiography, cardiomyopathy, pericardial |
| angi/o, vas/o | Vessel | Angiography, vascular, angioplasty |
| ather/o | Fatty plaque | Atherosclerosis (plaque in arteries) |
| thromb/o | Clot | Thrombosis (clot formation), thrombus, thromboembolism |
| gastr/o | Stomach | Gastroschisis (abdominal wall defect), gastric |
| enter/o | Intestine | Mesentery, enterocolitis (NEC) |
| cyst/o | Bladder, sac | Cholecystitis, cystic (relating to cysts), polycystic |
| uter/o, metr/o, hyster/o | Uterus | Endometrium, myometrium, hysterectomy |
| oophor/o, ovari/o | Ovary | Oophorectomy, ovarian torsion |
| salping/o | Fallopian tube | Salpingitis, hydrosalpinx |
| orch/o, test/o | Testis | Orchitis, cryptorchidism (undescended testis) |
| encephal/o | Brain | Encephalocele, anencephaly, holoprosencephaly |
| oste/o | Bone | Osteogenesis imperfecta, osteoporosis |
| my/o | Muscle | Myocardium (heart muscle), myometrium (uterine muscle) |
Directional & Positional Terms
| Term | Meaning | Clinical Use |
|---|---|---|
| Anterior / Posterior | Front / Back | Anterior placenta, posterior acoustic enhancement |
| Superior / Inferior | Above / Below | Superior mesenteric artery, inferior vena cava |
| Medial / Lateral | Toward midline / Away from midline | Medial epicondyle, lateral ventricle |
| Proximal / Distal | Closer to / Farther from origin | Proximal ICA stenosis, distal DVT |
| Superficial / Deep | Near surface / Away from surface | Superficial femoral vein, deep venous thrombosis |
| Sagittal | Lengthwise (head-to-toe) plane | Sagittal view of aorta, sagittal uterus |
| Transverse (axial) | Cross-section plane | Transverse view of carotid, transverse cervix |
| Coronal | Front-to-back dividing plane | Coronal view of kidney (long axis), coronal cranial US |
| Cephalad / Caudad | Toward head / Toward feet | Cephalic presentation (head down), caudal regression |
| Hepatopetal / Hepatofugal | Toward liver / Away from liver | Portal vein flow: hepatopetal = normal; hepatofugal = portal HTN |