Learn the physics, anatomy, equipment, and clinical applications behind X-ray, CT, MRI, and every major imaging modality.
Each modality page covers the underlying physics, how the equipment works, interactive diagrams, clinical applications, and key concepts for your exams.
From Röntgen's accidental discovery in 1895 to modern digital imaging. An interactive timeline of the milestones that shaped medical imaging.
Timeline · PioneersThe foundation of all medical imaging. Understand X-ray tube physics, image formation, exposure factors, and diagnostic applications.
Ionizing · DiagnosticHarnessing high-frequency sound waves for real-time imaging. Explore the piezoelectric effect, transducer types, and Doppler techniques.
Non-Ionizing · Real-TimePowerful soft-tissue contrast using magnetic fields and radio waves. Learn proton physics, pulse sequences, and scanner safety protocols.
Non-Ionizing · Soft TissueCross-sectional anatomy from a rotating X-ray beam. Understand Hounsfield units, multi-detector arrays, and helical scanning.
Ionizing · Cross-SectionFunctional imaging with radiopharmaceuticals. Explore SPECT, PET, gamma camera principles, and radionuclide therapy applications.
Ionizing · FunctionalUsing ionizing radiation to treat cancer. Understand LINAC machines, treatment planning, fractionation, and the role of the radiation therapist.
Therapeutic · LINACPractical, evidence-informed guides for radiography students and professionals.
Radiography images the body; radiotherapy treats cancer. Compare the two careers, the radiation each uses (kV vs MV), and why September 7 is World Radiotherapy Awareness Day.
September 6, 2026 ☢️ PhysicsWhy doubling the distance from an X-ray tube quarters the beam intensity — inverse square law formula, the direct square law (mAs₂ = mAs₁ × (D₂/D₁)²) for SID technique changes, worked examples, and ARRT exam tips on distance-based radiation protection.
September 4, 2026 ☢️ PhysicsUnderstand size distortion (magnification factor = SID/SOD) and shape distortion (elongation vs foreshortening) — plus why the PA chest uses a 72-inch SID to limit cardiac magnification, with ARRT exam tips and worked problems.
September 2, 2026 🦴 PositioningDedicated scaphoid (navicular) positioning guide — PA axial Stecher method, ulnar deviation elongating view, lateral oblique, centering points, the retrograde blood-supply rationale, ARRT exam tips, and the imaging pathway.
August 31, 2026 💉 ProceduresLearn what endoscopic retrograde cholangiopancreatography (ERCP) is, why iodinated contrast is used instead of barium, the fluoroscopy technique, prep, common complications, and ARRT exam tips.
August 29, 2026 ☢️ PhysicsLearn what half-value layer (HVL) measures, how beam filtration controls beam quality, the FDA minimum HVL standards in mm Al, and ARRT-tested exam tips for rad techs.
August 28, 2026 ☢️ PhysicsLearn how x-ray collimation cuts patient dose and scatter while sharpening contrast — collimator parts (lead shutters, light beam diaphragm, PBL), the digital histogram pitfall, and 7 ARRT-tested rules for rad techs.
August 26, 2026 ☢️ PhysicsUnderstand radiation dose units for the ARRT — gray, sievert, rad, and rem, absorbed vs equivalent vs effective dose, radiation weighting factors (wR), US NCRP vs ICRP dose limits, and typical imaging doses in mSv.
August 24, 2026 💉 ProceduresComplete myelography guide for rad techs — nonionic iodinated intrathecal contrast, CT myelography, indications, lumbar puncture technique, Trendelenburg positioning, patient prep, aftercare, and ARRT exam safety points.
August 22, 2026 ⚡ PhysicsUnderstand every factor behind radiographic image sharpness and geometric unsharpness — focal spot size, SID, OID, motion, the detector, and quantum mottle — with the Ug = F × OID/SOD formula and ARRT exam tips.
August 21, 2026 🦴 PositioningMaster the shared language of radiography — projection and position terms like AP, PA, and lateral decubitus, the four body habitus types, and the palpable bony landmarks that anchor your centering. 30 ARRT exam terms in plain English.
August 19, 2026 ⚡ PhysicsUnderstand the five ways x-rays interact with matter — photoelectric (Z³/E³) builds contrast, Compton dominates in soft tissue and creates scatter fog, and why kVp choice controls image contrast. ARRT exam essentials.
August 17, 2026 🦴 PositioningComplete AC joint X-ray positioning guide — Pearson weight-bearing AP, Zanca, and Alexander methods with centering points, CR angles, Rockwood classification, and ARRT exam tips.
August 14, 2026 🛡️ Radiation SafetyPregnancy and x-ray safety guide for rad techs — fetal dose limits for declared pregnant workers, the 10-day rule, conceptus dose table, shielding guidance, and ARRT exam tips.
August 12, 2026 🦴 Bone DensitometryComplete DEXA scan guide for rad techs — AP spine, hip, and forearm positioning, T-scores vs Z-scores, patient prep, quality control, the ARRT Bone Densitometry credential, and exam tips.
August 10, 2026 💉 ProceduresComplete arthrography guide for rad techs — direct and indirect technique, iodinated vs gadolinium contrast, fluoroscopic procedure steps, joint-specific approaches, adhesive capsulitis findings, and ARRT exam tips.
🦴 PositioningComplete soft tissue neck X-ray positioning guide for rad techs — AP and lateral upper airway views with CR centering at C4, epiglottitis thumb sign, croup steeple sign, prevertebral space, and ARRT exam tips.
August 7, 2026 🦴 PositioningComplete temporal bone X-ray positioning guide for rad techs — AP axial 35°, mastoid lateral oblique, profile, Stenver's, and SMV views with Clark's centering points and ARRT exam tips.
August 5, 2026 ⚡ PhysicsComplete X-ray tube guide for ARRT prep — cathode, filament, focusing cup, rotating anode, focal spot sizes, line-focus principle, heel effect, tube failure causes, and practice questions.
August 4, 2026 🦴 PositioningComplete orbit X-ray positioning guide for rad techs — modified occipito-mental, OM 30° caudad, optic foramina oblique, and lateral views with Clark's centering points and ARRT exam tips.
August 3, 2026 🦴 PositioningComplete nasal bone X-ray positioning guide for rad techs — lateral, PA, Waters, and superoinferior tangential views with Clark's centering points, evaluation criteria, ARRT exam tips, and practice questions.
July 29, 2026 🦴 PositioningComplete SI joint positioning guide — AP axial (15° cephalic Ferguson method), RPO/LPO oblique projections with Clark's centering points, evaluation criteria, and ARRT exam tips.
July 27, 2026 💼 CareerComplete radiologic technologist resume and interview guide — cover letter tips, common interview questions, salary negotiation strategies, and job search advice for new rad tech graduates entering the medical imaging field.
July 27, 2026 🦴 PositioningComplete tibia and fibula positioning guide — AP & lateral views with Clark's centering points, joint inclusion rules, leg-length imaging methods, ARRT exam tips, and practice questions for rad techs.
July 26, 2026 🔬 PhysicsEssential radiation biology guide for rad techs — cell damage mechanisms, deterministic vs stochastic effects, tissue radiosensitivity, and ARRT exam prep with practice questions.
July 25, 2026 🦴 PositioningComplete zygomatic arch X-ray positioning guide — SMV, tangential jug handle, AP axial Towne, and PA axial Titterington views with Clark's centering points and ARRT exam tips.
July 24, 2026 💼 CareerComplete CT technologist career guide — ARRT post-primary certification pathways, salary ($68K-$82K), job duties, education requirements, clinical competencies, and CT registry exam prep for rad tech students.
July 24, 2026 🦴 PositioningComplete paranasal sinus X-ray positioning guide — Waters, Caldwell, lateral, SMV, and open-mouth views with Clark's centering points and ARRT exam tips for rad tech students.
July 23, 2026 🦴 PositioningComplete humerus X-ray positioning guide for rad techs — AP, lateral, and transthoracic (Lawrence method) views with centering points, SID, IR sizing, evaluation criteria, and ARRT exam tips.
July 22, 2026 🦴 PositioningComplete TMJ X-ray positioning guide — axiolateral (Schüller method), PA transoral, and AP axial views with Clark's centering, open vs closed mouth comparison, and ARRT exam tips.
July 22, 2026 🦴 PositioningComplete scoliosis series positioning guide for rad techs — PA, lateral, and bending views with Cobb angle measurement, Clark's references, and ARRT exam tips.
July 20, 2026 🦴 PositioningComplete mandible X-ray positioning guide for rad techs — axiolateral oblique with rotation guide, PA axial, and AP axial Towne method with Clark's centering points and ARRT exam tips.
July 17, 2026 🦴 PositioningMaster clavicle X-ray positioning for rad techs — AP and AP axial (cephalic) views with Clark's centering points, technique charts, trauma considerations, companion shadow identification, and ARRT exam tips.
July 15, 2026 🦴 PositioningMaster shoulder X-ray positioning for rad techs — AP internal/external rotation, Grashey (true AP), scapular Y-view, axillary lateral, and trauma shoulder series. Centering points, evaluation criteria, and ARRT exam prep questions.
July 15, 2026 🦴 PositioningThoracic & lumbar spine positioning guide for radiography students — AP, lateral, swimmer's, oblique, spot L5-S1 and scoliosis views with centering points, evaluation criteria, and ARRT exam tips.
July 14, 2026 🦴 PositioningComplete elbow X-ray positioning guide for rad techs — AP, lateral, oblique, and radial head views with Clark's centering points, technique charts, fat pad sign interpretation, Coyle method, and ARRT exam tips.
July 13, 2026 🦴 PositioningAdvanced cervical spine X-ray positioning guide — trauma clearance protocols, ABCS evaluation method, normal variants vs fractures, CT junction imaging, and ARRT-level practice questions for rad techs.
July 13, 2026 🦴 PositioningComplete pelvis X-ray positioning guide for rad techs — AP pelvis, Judet views, inlet and outlet projections, trauma considerations, centering, IR sizes, and ARRT exam tips for each projection.
July 12, 2026 🦴 PositioningAdvanced rib X-ray positioning — clinical decision-making for PA vs AP vs oblique, specialized lordotic projections, CT imaging algorithms, normal variants that simulate fractures, and pathology recognition.
July 11, 2026 🦴 PositioningMaster femur X-ray positioning — AP full-length, lateral recumbent, and horizontal beam lateral (trauma) views with Clark's centering points, technique charts, evaluation criteria, and ARRT exam tips for rad techs.
July 10, 2026 💉 Patient CareHIPAA compliance for radiologic technologists — protected health information (PHI), minimum necessary rule, patient privacy in imaging areas, voice and data security, breach reporting, and real-world case scenarios for rad techs.
July 10, 2026 💡 EducationSystematic approach to radiographic image critique — evaluating positioning, collimation, exposure factors, anatomical coverage, and image quality. Templates for clinical image evaluation and ARRT exam preparation.
July 09, 2026 📝 Practice Test300+ practice questions covering ARRT & PART/RTLE licensing exams. Filter by topic, modality, and exam type. Random 100-question exams with instant feedback and score tracking.
🦴 PositioningComplete sacrum and coccyx X-ray positioning guide — AP sacrum (15° cephalad), AP coccyx (10° caudad), and lateral views with Clark's centering points, technique charts, evaluation criteria, and ARRT exam tips.
July 08, 2026 💉 Patient CareInfection prevention for rad techs — hand hygiene, standard precautions, transmission-based precautions, equipment disinfection protocols, isolation patient imaging workflow, and COVID-19 and emerging pathogen considerations.
July 08, 2026 💉 Patient CareEffective patient communication techniques for rad techs — explaining procedures, managing anxious patients, pediatric and geriatric communication, cultural sensitivity, and plain language strategies for informed consent.
July 07, 2026 🦴 PositioningComplete facial bones X-ray positioning guide for rad techs — Waters, modified Waters, Caldwell, lateral, SMV, and nasal bone views with Clark's centering points, evaluation criteria, and ARRT exam tips.
July 06, 2026 🛡️ SafetyEvidence-based pediatric dose reduction for rad techs — Image Gently campaign principles, size-based technique adjustments, shielding protocols, immobilization to avoid repeats, and dose monitoring for CT and X-ray.
July 06, 2026 🔬 ProceduresComplete HSG procedure guide — patient preparation, contrast instillation, fluoroscopic imaging sequence, tubal patency assessment, normal vs pathologic findings, and post-procedure care for rad techs.
July 5, 2026 🔬 ProceduresExcretory urography (IVU/IVP) guide — patient preparation, contrast injection timing, sequence of radiographs (scout, nephrogram, pyelogram, post-void), compression techniques, and alternative imaging for renal stones.
July 4, 2026 🔬 ProceduresComplete guide to barium contrast studies for rad techs — upper GI series, small bowel follow-through, barium enema preparation, double-contrast technique, fluoroscopic positioning, and contraindications.
July 03, 2026 🦴 PositioningComplete skull X-ray positioning guide for rad techs — lateral, PA, Caldwell, Towne, and AP projections with Clark's centering points, evaluation criteria, and ARRT exam tips.
July 3, 2026 💉 Patient CareEssential guide to contrast extravasation for rad techs — risk factors, signs and symptoms, severity classification, immediate management steps, documentation requirements, and patient follow-up protocols.
July 02, 2026 🦴 PositioningComplete hip X-ray positioning guide for rad techs — AP hip, frog-leg lateral, cross-table lateral, and Dunn method projections. Centering points, IR sizes, trauma considerations, and ARRT exam tips included.
July 01, 2026 🔧 TechnologyComplete guide to digital X-ray artifacts — CR plate artifacts (scratches, static, erasure), DR detector artifacts (dead pixels, calibration errors), grid artifacts, motion artifacts, and software processing artifacts with troubleshooting tips.
July 01, 2026 ⚡ PhysicsMaster automatic exposure control (AEC) in radiography: chamber selection, backup timer safety, density controls, and ARRT exam tips for technologists.
June 30, 2026 📖 EducationLearn how to choose the right radiologic technology program — compare JRCERT accreditation, clinical rotation quality, program costs, and ARRT pass rates to find the best career fit.
June 29, 2026 ⚡ PhysicsComprehensive guide to exposure technique charts for rad techs — fixed kVp vs variable kVp, AEC chamber setup, body habitus adjustments, EI targets, and ARRT exam prep.
June 28, 2026 💡 TechnologyComprehensive quality control program for radiography — daily QC checks for DR and CR systems, phantom testing, spatial resolution and contrast tests, AEC calibration, collimation accuracy, and regulatory compliance.
June 27, 2026 ⚡ PhysicsMaster scatter control: grid ratio, Bucky factor, 4 types of cutoff, air-gap technique, and evidence-based grid selection for the ARRT exam.
June 26, 2026 💡 TechnologyPACS and DICOM fundamentals every rad tech should know — image acquisition, storage, and retrieval, DICOM modalities and tags, HL7 interfaces, RIS-PACS integration, image compression, and troubleshooting connectivity issues.
June 26, 2026 📖 EducationMaster your clinical rotations with this complete guide — ARRT competency requirements, professional conduct tips, clinical success strategies, and how to pass every check-off in your radiography program.
June 24, 2026 💡 PhysicsUnderstanding digital radiography image processing — histogram analysis, look-up tables (LUTs), edge enhancement, spatial frequency processing, multi-frequency processing, and digital post-processing techniques for diagnostic optimization.
June 24, 2026 🔬 TechniquesC-arm fluoroscopy guide for rad techs — sterile-field protocol, OR positioning for common surgical procedures, NRC dose limits, and image troubleshooting.
June 23, 2026 📍 PositioningStep-by-step forearm X-ray positioning guide — AP and lateral forearm projections, radius and ulna technique, centering points, common errors, evaluation criteria, and ARRT exam tips for rad techs.
June 22, 2026 💡 TraumaComplete guide to trauma radiography — ATLS imaging protocols, cross-table lateral views, horizontal beam techniques, trauma series (cervical, chest, pelvis), and communication in the trauma bay.
June 21, 2026 🔬 TechniquesMaster portable X-ray technique — positioning patients in bed, trauma cart radiography, ICU chest X-rays, mobile C-arm guidance, radiation safety for portable exams, and image quality considerations.
June 20, 2026 🩻 Chest X-RayMaster portable chest X-ray technique — AP positioning methods, SID guidelines, grid decisions, common errors, ARRT exam prep, and evaluation criteria.
June 19, 2026 🔊 UltrasoundTwo breakthroughs in water-immersion whole-body ultrasound in one article: Caltech's research-grade system and Midjourney Medical's Ultrasonic CT with Butterfly Network chips.
June 19, 2026 💡 PediatricsComplete guide to pediatric radiography for rad techs — immobilization techniques, modified positioning for children, dose reduction strategies, gonadal shielding, and age-appropriate communication.
June 19, 2026 📍 PositioningStep-by-step foot and ankle X-ray positioning — AP, oblique, lateral foot views; AP, mortise, lateral ankle views; axial calcaneus projection. Weight-bearing vs non-weight-bearing considerations.
June 18, 2026 📖 EducationComplete guide to radiography program accreditation — what JRCERT accreditation means, how to find accredited programs, and why accreditation matters for ARRT exam eligibility and your rad tech career.
June 17, 2026 📍 PositioningComplete positioning guide for hand, wrist, and finger X-rays — PA, oblique, lateral, scaphoid views, and special projections for the thumb and digits. Common errors and evaluation criteria.
June 17, 2026 📍 PositioningUpper extremity X-ray positioning guide — hand, wrist, and elbow projections with Clark's centering points, technique charts, and ARRT exam tips for rad techs.
June 15, 2026 PhysicsMaster kVp and mAs — how kilovoltage and milliamperage affect X-ray beam quality, density, contrast, patient dose, and technique chart development for rad techs.
June 12, 2026 SafetyPatient shielding in radiography — why lead aprons and gonadal shielding are no longer recommended, the science behind the change, and what evidence-based practice looks like today.
June 14, 2026The list updates from the channel feed and keeps a local fallback if the feed is unavailable.
Designed to work alongside your radiography program curriculum.
Get context on how medical imaging evolved. Understanding the "why" makes the physics easier to remember.
Each page covers physics principles, equipment diagrams, clinical uses, and key terminology.
Hover or tap on interactive diagrams to reveal labels, explanations, and component descriptions.
Visual explainers show you exactly how each technology works — from X-ray production to MRI proton alignment.
Key differences at a glance.
| Modality | Energy Source | Ionizing? | Primary Use | Soft Tissue? |
|---|---|---|---|---|
| X-Ray | X-ray photons | Yes | Bone, chest, dense structures | Limited |
| Ultrasound | Sound waves (MHz) | No | Soft tissue, vascular, OB | ✓ Excellent |
| MRI | Magnetic field + RF | No | Brain, spine, joints, soft tissue | ✓ Superior |
| CT Scan | X-ray photons | Yes | Trauma, chest, abdomen, vascular | Moderate |
| Nuclear Medicine | Gamma rays | Yes | Functional imaging, metabolism | Moderate |
| Radiotherapy | High-energy photons/particles | Yes | Cancer treatment | — |
