Chapter 11 - Image Optimization for Ultrasound Guided Procedures

Image Optimization for Ultrasound Guided Procedures Julie A. Cardoso RVT, RPhS, RDCS Director of Accreditation Services for Cardiovascular Credentialing Consultants, LTD

Welcome to the Vein Experts Online Educational CME Program.

Original Release Date: 2/17/14 Termination Date: 1/31/2016 Price: 25.00 for Vein Experts Members & $40.00 for NonMembers - Processing/CME Fees

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This activity has been planned and implemented in accordance with the accreditation requirements and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint providership of The University of Toledo and VeinExperts.org.

• The University of Toledo is accredited by ACCME to provide continuing medical education for physicians.

• The University of Toledo designates this enduring activity for a maximum of 1.00 AMA PRA Category Credits™. Physicians should claim only credit commensurate with the extent of their participation in the activity.

For nurses, we are also able to issue a certificate of attendance stating the course is AMA approved, which may be eligible for credit. Nurses are responsible for submitting the certificate to their board.

Please note only one certificate can be issued for each purchase.

Disclosures: Ronald Bush, MD, FACS, faculty and planning member discloses he is on the Speaker’s Bureau for Dornier/Refine USA and is contracted with Water’s Edge Dermatology and Soffer Health.

Richard L. Mueller, MD, faculty and planning member, discloses he receives grant/research support from Vascular Insights, LLC Ariel Soffer, MD, FACC, faculty and planning member, discloses he is on the Speaker’s Bureau for Cutera , consults for Angiodynamics, & does research for BTG. Peggy Bush, APN, planning member, has no disclosures or financial interests and is employed by Midwest Vein & Laser Center.

Becky Roberts, planning member, has no financial interest or other relationships with any manufacturer of commercial product or service to disclose.

Julie A. Cardoso RVT, RPhS, RDCS, faculty and planning member, discloses she isConsultant and stock shareholder in Cardiovascular Credentialing Consultants, LTD and Per diem Cardiovascular Application Specialist for GE Healthcare North East Division

Purpose • The purpose of this presentation is to optimize ultrasound images for ultrasound guided procedures • The target audience for this activity includes physicians, and other health care professionals in Cardiology, Dermatology, Interventional Radiology. Phlebology, Surgery, Vascular Surgery, Wound Care Specialist who care for patients that undergo ultrasound guided procedures

Learning Objective • As a result of this activity, the participant should be able to • Describe how the ultrasound machine knobs play a vital role in optimizing images for ultrasound guided procedure • Describe how transducer positioning plays a vital role in image optimization

Image Optimization • Ultrasound machine settings should be changed as needed to optimize image quality • Understanding just a few of the knobs can accomplish this for most scans • Different presets for different transducers/structures/ patient species/sizes

Knobology •  What are these knobs and buttons for, and if I adjusting them what is their effect on my image quality?

Screen / Monitor • Adjust brightness / contrast, according to whether the room is bright or dark.

• Adjust before Gain

Gain • Overall gain – Amplification of received signal – Increase or Decreases the amount of returning echoes – Effects the brightening or darkening of the image

Time Gain Compensation • TGC – Compensates for beam attenuation (loss of energy as it passes through tissue – Controls amount of gain in the image at different depths up or down in the field view – Balances the image to equalize the brightness of echoes from the near field to the far field

Focus Points • Improved resolution is seen where the focal points are.

• Place focal points at the region of interest or below to achieve the sharpest image

Depth • Adjust as needed throughout scan • Shallow depth = better resolution • Deep depth = less resolution

Frequency • High frequency • Better resolution • Less depth • Lower frequency • Lower resolution • Better for depth

Gray Scale Resolution • Adequate gray scale resolution allows for the difference of subtle changes in the tissue • DYNAMIC RANGE determines how many shades of gray are demonstrated on an image

Dynamic Range • Dynamic Range (aka Compression) allows you to tell the ultrasound machine how you want the echo intensity displayed as shades of gray. A broad/wide (increase) range will display more shades of gray and an overall smoother image.

• A smaller/narrow (decrease) range will display fewer shades of gray and appear as a higher contrast with a more black-and-white image.

DYNAMIC RANGE • Decreased Dynamic Range

Dynamic Range Increased Dynamic Range

Gray Scale Many levels of brightness White, light gray, medium gray, dark gray, black,ect.

Assignment of different gray shades for each echo amplitude Different colors may also represent different signal strengths

Ultrasound Gray Maps A gray map determines how dark or light you prefer to show each level of white/gray/black based upon the strength of the ultrasound signal.

Gray maps adjust the brightness of each shade of gray.

Gray Scale Maps

Gray Maps vs. Dynamic Range •  Although they may appear to have a similar effect, they are very different. It often helps to adjust them in conjunction with each other to get the best image

Frame Average / Persistence • Frame averaging, or persistence, are similar functions in which multiple image frames are combined, or “averaged” into a single image. Its apparent affect is similar to that of Speckle Reduction, in which the image appears smoother and noise is reduced in the image.

Reject Reject or rejection filter tells the machine the minimum level of echo displayed. For example, if you have a lot of noise in the image, you can increase the Reject level to eliminate the weaker signals, thereby cleaning up the image and suppressing the weakest signals.

Edge Enhance The ultrasound attempts to make a sharper image by combining adjacent signals. This will have an effect of showing higher contrast and brighter edges of structures.

PERPENDICULAR Parallel 90 degree angle to skin to the target object = sharper image quality

TWO ANTATOMIC VIEWS • Transverse – Short Axis • Longitudinal - Sagittal

Transverse – Short Axis • Divides the body cross sectionally into top (superior) and bottom ( inferior) • Image is sliced horizontally

Transverse- Short Axis

Longitudinal - Sagittal •  Divides the body into right and left sections along a vertical axis

Longitudinal - Sagittal

FOUR BASCIC PROBE MOVEMENTS SLIDING ROCKING ANGLING ROTATING

ROCKING Banking the probe along the longitudinal axis of the beam.

In longitudinal view, this rocking motion will make vessels appear to head UPHILL or DOWNHILL; in transverse, the cross-sectional vessel will move SIDE TO SIDE Sliding: Moving the probe face along the surface of the skin, either towards the head (Cephalad) / towards the feet (Caudal) or Lateral / Medial

SLIDING Moving the probe face along the surface of the skin, either towards the head (Cephalad) / towards the feet (Caudal) or Lateral / Medial

ANGLING Sweeping the beam across its axis, side to side In longitudinal view, you would angle lateral and medial

ROTATING Twisting the probe to align the beam with desired structure

Optimizing Transverse Approach • Inject at the side of the transducer that is pointed towards the feet • Angle the transducer slightly towards the needle

Optimizing Transverse Approach • Go in with needle (bevel up) at an almost perpendicular (straight up and down) approach with the transducer OR • Go in with needle (bevel up) at a less steep angle with transducer

Optimizing Transverse Approach

Diagram and ultrasound images: Adapted from Chapter 19, Emergency Ultrasound Ed. 2, James Mateer MD, editor

Optimizing Longitudinal Approach • Inject at the side of the transducer that is pointed towards the feet • 90 degree angle to the skin. Not tilted to one side

Optimizing Longitudinal Approach • Line up the needle (bevel up) directly in the center of the end of the transducer

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Image courtesy of CAE Healthcare and Blue phantom ultrasound training models

Summary In conclusion the four probe movements ( rocking, sliding, angling and rotating) will help you find the target vein and will make your transducer perpendicular for easy access.

Adjusting your ultrasound system settings or screen / monitor will optimize your image.

Most ultrasound systems can save your image presets, so every time you pick up the transducer you will have an optimal image.

Evaluation How well did this activity present the objective?

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Exam What are two anatomic for vein access? a. Transverse and Short axis b. Transverse and Longitudinal c. Longitudinal and Sagittal d.  Grayscale and Transverse What two knob should you adjust for a more contrast image? a. Dynamic Range and Gray Maps b. Frequency and Depth c. Gain and TGC d. Focus point and Monitor / Screen What are the four basic probe movements? a. Sliding, Rocking, Angling and Rotating b. Sliding, transverse, long axis and Rotating c. Dynamic Range, Grayscale map, Rocking and Angling d. Frame rate, Rotating, Sliding and Rocking

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Was any commercial bias presented in the material?

No Yes (Please explain) _______________________________________________ I will be able to change my clinical practice as a result of participating in this activity?

No Yes What topics about ultrasound would you like to hear about in the future? ______________________________________________

Additional Comments / Recommendations ___________________________________ ___________________________________

Contact Information Name & Credentials __________________ ___________________________________ Address ____________________________ ___________________________________ Phone Number ______________________ Email Address_______________________

References Introduction to Vascular Scanning, A guide for the complete beginner; Donald P. Ridgway, RVT 3rd ed., Pasadena, Davies Publishing, 1998 Practical Phlebology: Venous Ultrasound; CRC Press, 2013 Jospeh Zygmunt, Jr, Oliver Pichot, Tracie Duplaise Understanding Ultrasound Physics, 3rd ed. ‘2004, ESP Inc., Edelman SK Vascular Technology – An Illustrated Review. 4th ed.

Pasadena, Davies Publishing, 2009 Rumwell C, McPharlin M,