artifacts ultrasound in regional anesthesia
TRANSCRIPT
![Page 1: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/1.jpg)
Artifacts
ULTRASOUND
![Page 2: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/2.jpg)
• any record or image obtained in the course of
applying a medical diagnostic technique which is
not representative of the structures under study but
is adventitious”.
![Page 3: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/3.jpg)
• When evaluating anatomic structures, acoustic
artifacts result in added (not real), missing,
improperly located, brightness, shape or size
alterations
![Page 4: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/4.jpg)
Ultrasound
• US waves wavelength and frequency are inversely related
• Low frequency - Better penetration of tissues – good resolution of deeper structures
• High frequency probes used for superficial structures visualization
• Higher frequency waves are more attenuated than lower frequency for a given distance
• 1-20Mhz probes• Atlas of Ultrasound-Guided Procedures in Interventional Pain Manag ement
![Page 5: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/5.jpg)
• Increasing the transducer frequency improves the
spatial resolution at the expense of beam
penetration as a result of sound wave absorption. In
contrast, lower frequency transducers enable
assessment of deeper structures, but the spatial
resolution is lower.
![Page 6: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/6.jpg)
• Angle of insonation
• maximum reflection achieved when the sound wave
is directed perpendicular to the imaged structure
• In addition to reflection, the sound waves also be
absorbed in the examined tissues, and the amount
of absorption increases with greater transducer
frequency and tissue viscosity.
![Page 7: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/7.jpg)
![Page 8: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/8.jpg)
![Page 9: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/9.jpg)
• Acoustic Shadowing: Acoustic shadowing is the
reduction in amplitude of reflected sound caused by
reflectors that lie behind a strongly reflecting or
attenuating structure
![Page 10: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/10.jpg)
![Page 11: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/11.jpg)
Acoustic Reflection and Refraction
![Page 12: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/12.jpg)
Acoustic Enhancement: Acoustic enhancement is a relative
increased echo amplitude caused by an intervening structure
of low attenuation
![Page 13: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/13.jpg)
Ring-down and comet-tail artifacts
![Page 14: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/14.jpg)
Reverbation
![Page 15: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/15.jpg)
![Page 16: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/16.jpg)
![Page 17: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/17.jpg)
![Page 18: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/18.jpg)
![Page 19: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/19.jpg)
![Page 20: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/20.jpg)
![Page 21: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/21.jpg)
![Page 22: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/22.jpg)
![Page 23: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/23.jpg)
![Page 24: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/24.jpg)
![Page 25: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/25.jpg)
![Page 26: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/26.jpg)
![Page 27: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/27.jpg)
![Page 28: artifacts ultrasound in regional anesthesia](https://reader031.vdocuments.mx/reader031/viewer/2022022415/5a674bb77f8b9a8a378b457b/html5/thumbnails/28.jpg)
• Regional Anesthesia and Pain Medicine Vol. 32 No.
5 September–October 2007
• Ultrasound, Vol. 36, No. 4, 1995, pp 297-306.
• Seminars in Musculoskeletal Radiology Vol. 18 No.
1/2014