Ultrasound Lecture 1 - PDF

SHENNA MARIE G. FORRO, RRT, MSRT ULTRASONOG OBJECTIVES: ▸Explain the purpose of ultrasound ▸Describe the nature and principles of ultrasound ▸Understand the history of ultrasound ▸Explain the biological effect of ultrasound INTRODUCTION TO ULTRASOUND ULTRASOUND IMAGING “SONOGRAPHY” ‣ Involves...

SHENNA MARIE G. FORRO, RRT, MSRT ULTRASONOG OBJECTIVES: ▸Explain the purpose of ultrasound ▸Describe the nature and principles of ultrasound ▸Understand the history of ultrasound ▸Explain the biological effect of ultrasound INTRODUCTION TO ULTRASOUND ULTRASOUND IMAGING “SONOGRAPHY” ‣ Involves exposing part of the body to a high frequency sound waves to produce pictures of the inside of the body ‣ Because ultrasound images are captured in real-time, they can show the structures and movement of the body’s internal organs, as well as blood flowing through the blood vessel (interactive process) INTRODUCTION TO ULTRASOUND SONOGRAPHY ▸Sonus: Sound ▸Graphien: To write INTRODUCTION TO ULTRASOUND ‣Ultrasound is the name given to high frequency sound waves ‣Acoustic vibrations of frequencies higher than 20 kHz (2-20 MHz) ‣Non-audible by human ear HUMAN HEARING ‣20 - 20,000 Hz  ADVANTAGES & DISADVANTAGES ‣ NON-ION ‣ OPERA IZING TOR ‣ NO IV DEPEN INJECTI DENCE ON ‣ BONE, ‣ PORTAB AIR/GAS ULTRASOUND HISTO RY HISTORICAL DEVELOPMENT 1.LAZARO SPALLANZANI (1794) ‣Analyzed the basic mechanisms of the navigation of flying bats in the dark, and rightly deduced that bats employed sound rather than light to orient themselves ‣Discovered echolocation or bio sonar ULTRASOUND USED BY BATS ‣ When bats emit ultrasound from their mouth, they can hear high frequency that they make while flying ‣ They listen to the vibration that return from various objects near them ECHOLO CATION The use of sound waves or echoes to determine the location  HISTORICAL DEVELOPMENT 2. SIR FRANCIS GALTON (1880) ‣Created and produced the apparatus that was able to produce the sound waves of a frequency of 40 hertz. ‣Whistle HISTORICAL DEVELOPMENT 3. PAUL-JACQUES CURIE & PIERRE CURIE (1880) ‣ Discovered piezoelectricity ‣ Noted that electricity may be created in a crystal of quartz under mechanical vibrating HISTORICAL DEVELOPMENT 4. PAUL LANGEVIN 1915 (WORLD WAR 1) ‣ Research the use of high-frequency sound waves to find German submarines. ‣ SONAR (Sound Navigation and Ranging) ‣ 1916 - the first working version of a marine SONAR system was used during the first HISTORICAL DEVELOPMENT 4. PAUL LANGEVIN 1915 (WORLD WAR 1) ‣ Invented Hydrophone first transducer HISTORICAL DEVELOPMENT 5. SY SOKOLOV (1928) ‣ First proposed the idea of ultrasound to find flaws deep in metal structures HISTORICAL DEVELOPMENT 6. DR. KARL DUSSIK (1940) ‣Credited for being the first to use ultrasound in medical diagnosis when he used two transducers positioned on opposite sides of the head to measure ultrasound transmission profiles. ‣He transmitted an ultrasound beam through the human skull in attempts of detecting brain tumors HISTORICAL DEVELOPMENT HISTORICAL DEVELOPMENT 7. WILLIAM FRY ‣Credited with being the first to introduce the use of computer in diagnostic ultrasound 8. GEORGE LUDWIG ‣Interested in reflections from gallstones, demonstrated that when ultrasound waves generated by a piezoelectric crystal transducer are transmitted into the body, ultrasound waves of different acoustic impedances are returned to the transducer. HISTORICAL DEVELOPMENT 9. IAN DONALD (1956) ‣ Introduced the ultrasound in diagnostic and medicine ‣ He used the one-dimensional (A-Mode) to measure the parietal diameter of the fetal head ‣2 YEARS LATER ‣ Ian Donald & Tom Brown presented the ultrasound image of a female genital tumor. HISTORICAL DEVELOPMENT HISTORICAL DEVELOPMENT 10. TOM BROWN ‣ Invented the “Two Dimensional Compound Scanner” ‣ enabled the examiner to visualize the density of the tissue 11. LATE 1950S ‣ The first contact compound B-scanner (using olive oil as a lubricant) was developed. This equipment used an articulating arm to produce static images. HISTORICAL DEVELOPMENT 12. 1970S ‣ gray scale imaging was introduced, enabling the display of a wide range of echo amplitudes. 13. MID 1970S ‣ Real-time scanning systems were introduced. ‣ Dynamic sonographic information was available for the first time. 14. 1980S ‣ Doppler technique BIOLOGIC EFFECTS OF ULTRASO BIOLOGICAL EFFECTS OF ULTRASOUND BIOLOGICAL EFFECTS OF ULTRASOUND THERMAL MECHANI EFFECT CAL EFFECT BIOLOGICAL EFFECTS OF ULTRASOUND THERMAL EFFECTS ‣ Slight temperature rise near the transducer ‣ Significant near bone-tissue interfaces. ‣ Pulsed Doppler has higher potential for heating. BIOLOGICAL EFFECTS OF ULTRASOUND MECHANICAL EFFECTS ‣ Includes cavitation pressure END OF DISCUSSION ULTRASONOG