Lesson 1Sound wave fundamentals: frequency, wavelength, propagation, acoustic impedanceIntroduces essential sound wave properties pertinent to ultrasound imaging, encompassing frequency, wavelength, propagation speed, and acoustic impedance, and delineates how these factors govern reflection, refraction, and transmission at interfaces.
Frequency, period, and clinical rangesWavelength and spatial resolution linksPropagation speed in different tissuesAcoustic impedance and reflectionRefraction and transmission at boundariesIntensity, power, and beam profilesLesson 2Basic troubleshooting: noise, probe contact problems, and cable/instrument checksOffers a systematic method for addressing substandard images, involving identification of noise, verification of probe contact and gel application, examination of cables and connectors, and determination of when equipment servicing is necessary.
Identifying electronic and speckle noiseImproving probe contact and gel useChecking cables, connectors, and portsVerifying presets and default settingsSimple on-the-spot functional testsWhen to escalate to technical serviceLesson 3Doppler basics (overview): colour vs spectral Doppler principles and limits for bedside useIntroduces Doppler physics tailored for bedside application, contrasting colour and spectral Doppler, addressing aliasing and angle dependence, and outlining practical constraints in emergency and critical care scenarios requiring swift, targeted evaluations.
Principles of the Doppler frequency shiftColour Doppler flow mapping and settingsSpectral Doppler waveforms and indicesAngle dependence and aliasing limitationsPractical bedside Doppler applicationsCommon Doppler pitfalls and artefactsLesson 4Transducer types and beam formation: linear, curvilinear, phased-array characteristicsDescribes linear, curvilinear, and phased-array transducers, the variations in beam formation between them, and how footprint, frequency, and field of view inform probe selection for vascular, abdominal, cardiac, and lung imaging.
Linear probes and high-resolution imagingCurvilinear probes and abdominal viewsPhased-array probes and cardiac windowsBeam steering, focusing, and apodisationProbe frequency ranges and applicationsSelecting probes for point-of-care examsLesson 5Attenuation and depth: effects of frequency selection on depth and image qualityExamines how ultrasound energy diminishes with depth, the impact of frequency selection on penetration and resolution, and strategies to equilibrate image brightness, noise, and diagnostic detail for superficial versus deep structures.
Mechanisms of attenuation in soft tissueFrequency versus penetration trade-offsFrequency effects on axial and lateral resolutionOptimising settings for superficial targetsOptimising settings for deep structuresRecognising attenuation-related artefactsLesson 6Focusing, focal zones, and near/far field optimisationAddresses how focusing and focal zones constrict the beam, enhance lateral resolution, and vary in near and far fields. Stresses the selection and placement of focal zones to optimise visualisation of target structures at diverse depths.
Near field, focal zone, and far field basicsElectronic versus fixed focusing methodsEffect of focus on lateral resolutionChoosing number and depth of focal zonesOptimising focus for superficial targetsOptimising focus for deep structuresLesson 7Common artefacts: reverberation, shadowing, enhancement, mirror image, comet-tail, A/B-lines, ring-downReviews principal ultrasound artefacts, their origins, and methods to identify and utilise or mitigate them. Highlights reverberation, shadowing, enhancement, mirror image, comet-tail, A- and B-lines, and ring-down in point-of-care examinations.
Reverberation and multiple reflection patternsAcoustic shadowing and clean versus dirty shadowsPosterior acoustic enhancement mechanismsMirror image and duplication artefactsComet-tail, ring-down, and short-path artefactsA-lines, B-lines, and lung artefact patternsLesson 8Resolution and penetration: axial, lateral, and elevational resolution trade-offsDetails axial, lateral, and elevational resolution, their dependence on pulse length and beam width, and how probe selection, depth, and focusing influence the balance between detailed imaging and sufficient penetration in clinical practice.
Axial resolution and spatial pulse lengthLateral resolution and beam widthElevational resolution and slice thicknessDepth, focusing, and resolution changesProbe selection for optimal resolutionBalancing resolution against penetrationLesson 9Time-gain compensation, overall gain, and dynamic range: purpose and practical adjustmentsExplains how time-gain compensation, overall gain, and dynamic range affect image brightness and contrast. Concentrates on practical controls to compensate for depth-related attenuation and prevent over- or under-gaining of structures.
Overall gain and global brightness controlTime-gain compensation curve shapingDynamic range and image contrast controlRecognising overgain and undergain patternsDepth-specific adjustments during scanningPreset use and manual fine-tuningLesson 10Safety and bioeffects: thermal and mechanical indices, ALARA principle, safe scanning timesOutlines ultrasound safety principles, incorporating thermal and mechanical indices, ALARA, and safe exposure durations. Emphasises practical measures to reduce risk whilst preserving diagnostic image quality in vulnerable patients.
Thermal index meaning and limitationsMechanical index and cavitation riskALARA principle in daily practiceSafe scanning times by patient groupHigh-risk scenarios and mitigationRegulatory guidelines and labelling
