Ultrasound 1F03 Presentation F2024 PDF

Ultrasound Specialization MedRadSc 1F03 Diagnostic Ultrasound Isn’t only about babies!  Objectives for today Project analysis slide 2 Describe the purpose of Introduce th...

Ultrasound Specialization MedRadSc 1F03 Diagnostic Ultrasound Isn’t only about babies!  Objectives for today Project analysis slide 2 Describe the purpose of Introduce the physics of ultrasound and types of ultrasound examinations performed Appreciate ultrasound as part Ultrasound of other modalities within Role of the ultrasound technologist Specializati diagnostic imaging, or a larger on hospital Recognize importance of critical Visualize sonography as a thinking and communication career What is Ultrasound? Sound we can hear 20-20000 Hz “ULTRA” Sound =Above human hearing range Diagnostic Ultrasound uses 2-24 MHz 4 1MHz = 1 000 000 Hz How is it done? This Photo by Unknown Author is licensed under CC BY 5 Pulse Echo Technique The physics behind the modality…. Acoustic Impedance Based on the ACOUSTIC IMPEDANCE of the tissue that the wave encounters, many processes may occur that contribute to the overall sonographic image that is produced. Intensity of the beam is reduced as a function of distance, and the number of interactions the wave encounters. WHAT ARE THESE PROCESSES? 1. Transmission 2. Absorption Collectively 3. Reflection described as: 4. Refraction ATTENUATIO 5. Scatter N Conversion of energy Attenuation (reduction of transmitted beam) may occur through Absorption (converted to heat) Reflection back to the transducer (back to electric signal to form image) Scattering (also helps with image formation, but some of the echoes are lost) Refraction (change in direction as it passes through mediums of different density = artifacts) Image: American College of Emergency Physicians, 10 ACEP How are images produced? The machine uses: Assumed speed of sound (1540 m/s) The “time of flight” for the echo to leave the transducer and be reflected back to calculate the depth of the “dot” to represent the interaction for that wave Distance Equation and Echo Location From Miele, 2020 Chapter 1 Frequency of waves 2-24 MHz frequency range used in diagnostic ultrasound Frequency is dependent on wavelength; shorter wavelengths = higher frequencies and vice versa We can change/manipulate frequency when scanning! Higher frequency provides more detail, but less penetration of sound (depth of imaging is sacrificed) KEY: the higher the frequency the better the resolution but the lower the penetration!  GOLDEN RULE IN DIAGNOSTIC U/S IMAGING: Optimizing the sonographic image requires constant critical thinking… I.E. SCANNING AT THE HIGHEST FREQUENCY GIVES US THE BEST RESOLUTION; HOWEVER, LIMITS OUR ABILITY TO PENETRATE DEEP STRUCTURES. ALWAYS SCAN AT THE HIGHEST Why the BRIGHTNESS VARIABILITY? Very bright = ECHOGENIC No echo = ANECHOIC Changes in: -Medium -Acoustic Impedance -Reflection Types -Absorption Changes Kremkau, (2016) Fig 1.1 “Enemies” of ultrasound The machine assumes transmission speed of sound through soft tissue at 1540 m/s. Significant differences (high acoustic impedance mismatch) of adjacent tissue types or matter causes significant attenuation!! Acoustic Impedance (Z) = DENSITY (kg/m3) x velocity lung (V) 0.18 × 106 fat 1.34 × 106 kidney 1.63 × 106 liver 1.65 × 106 muscle 1.71 × 106 bone 7.8 × 106 Reflection fraction = [(Z2 - Z1) / (Z2 + Z1)]2 Comparison of modalities Air on Air on Xray ultrasound Air on CT Physics Checkpoint 1 Why do we need to use gel during any ultrasound study? This Photo by Unknown Author is licensed under CC BY-NC 2 The acoustic impedance (Z) of a medium is calculated using what two values? 3 To perform an abdominal ultrasound, you might select a 5 MHz transducer frequency – knowing this, what transducer frequency would you select to perform a thyroid ultrasound? 2MHz ? 10MHz ? Purpose of ultrasound (exam types) Fetal growth/monitoring Thyroid Abdomen Breast Liver, kidneys, pancreas, Testicles gallbladder, spleen, etc Heart (cardiac Pelvic organs sonography) Blood vessels Brain-neonatal Joints Muscles and tendons Bowel Intraoperative procedure 2D, 3D, real-time A requisition and a clinical question for every patient Requisition Clinical questions will determine protocol Abdominal pain - ?gallstones Pelvic pain - ?ovarian pathology Dating for early pregnancy Palpable thyroid nodule Recent stroke - ?carotid stenosis Shoulder injury - ?rotator cuff Performing ultrasound Role of the ultrasound technologist Ultrasound A safe (no ionizing radiation), portable, reliable and economical diagnostic imaging technique to assess NORMAL vs. ABNORMAL ALARA: As Low As Reasonably Achievable ?Thermal bioeffects from ultrasound How can we implement ALARA in our practice? Power output: reduce power where you can without compromising the exam Power: quantified as MI (mechanical index) and TI (thermal index) Minimize the amount of time the transducer/beam is stationary Minimize use of colour Doppler and spectral Doppler unless clinically warranted, especially in utero. Key Points Working in the dark Very hands-on, close proximity with patients Considered most “user dependent” modality Use of gel, proper ergonomics, optimized images Cases 10 minutes – 2 hours Patient preparation variable depending on study Safe for vulnerable patients (neonates, prenatal imaging, repeat imaging) Available, cost effective, used for acute and routine exams You are the eyes and ears for the radiologist and ordering physician EQUIPMENT OPTIONS…. What do we need to know? A thorough understanding of relational anatomy and pathology!  Sonographer skills needed Communication Applied knowledge Critical thinking Skills Judgement Technical Skills Professional Behaviours Organizational Skills Communication as a Sonographer Honesty Courtesy Integrity Respect Compassion Professional Empathy This Photo by Unknown Author is licensed under Competen CC BY-SA-NC t Optimizing patient care Communicatio n Critical thinking Adaptability This Photo by Unknown Author is licensed under CC BY-SA What information can ultrasound provide? Ultrasound can characterize the features of pathology that has been identified. Location Size Mobility Compressibility Vascularity Composition Borders Technical impressions Sonographers complete technical impression worksheets after case completion Record measures Describe echotexture or lesions NAD (no abnormality detected) or describe pathology We do not diagnose or finalize reports (radiologists do this) Sonography is collaborative! This Photo by Unknown Author is licensed under CC BY-ND Ergonomics and Repetitive Strain Injury Siemens Healthcare Work environments Private clinics, small practices Fewer techs (~1-3), specialized studies, outpatients with scheduled appts Vascular labs, fertility clinics, ob/gyn offices, or general outpatients, breast clinic Urgent care or community hospital Medium sized depts (~3-8 techs) Combination of booked patients and urgent add-ons. Acute care, tertiary care hospital setting Large departments (ie McMaster hospital has 12-14 techs on at a time), many sonographers sharing workload, complex cases Opportunities Sonography Canada, CMRITO Write your registration exams: Required for working in Ontario: Maintenance of registration required through: Payment of annual fees Completion of CMEs (continuing medical education credits) Liability insurance Adhering to policies, codes https://sonographycanada.ca/resources/competencies-standards  Code of Ethics, QA programs Defines: Scope of practice Maintain standards Behavioural code Liability Maintain records of registration and CMEs “Its purpose is to assure the profession’s quality of practice, and to promote registrants’ continuing This Photo by Unknown Author is licensed under CC BY-ND evaluation, competence, and https://www.cmrito.org/pdfs/code/code-of-ethics.pdf improvement. Sonography Canada – Professional Practice Guidelines. How do I start? 4 5 3 1 2 The illusive ultrasound image… NORMAL Liver ABNORMAL Liver Normal Kidney Blood Flow Assessment Vascular BioDigital Human  Rumack and Levine, 5th ed Neurosonography Interventional procedures Other imaging techniques  What makes a good Project analysis slide 3 sonographer KNOWLEDG TECHNICAL ETHICS WILLINGNE COMMUNICATI E SKILLS SS TO ON Patient care and GROW AND Hand-eye Professionalism, LEARN Physics, anatomy, communication, Being open to coordination, adherence to relational anatomy, cultural sensitivity learning machine ethical and physiology, and awareness, opportunities manipulation and professional pathophysiology. communication throughout your image guidelines, ALARA, and interpersonal career, and optimization, humility, integrity skills with other adapting with ability to transcend sonographers and changing didactic knowledge radiologists technology. into practice. https://www.youtube.com/watch?v=ehgOOoNnTp0 Thank You Outside sources: The National Institure of Biomedical Imaging and Bioenginering. The National Institure of Health “How Ultrasound works.” Online video clip Youtube Oct 06, 2021 Society of Diagnostic Medical Sonographers. “ Why Sonographers do What they Do?” Online video clip Youtube (27 Jun 2014) https://www.youtube.com/watch?v=ehgOOoNnTp0