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Persistence

1. Continues to display information from older images

2. Number of previous frames are superimposed on the most current frame
- Positives: Improves image quality during real-time acquisition
: Smoother image with reduced noise (higher signal to noise ratio)
- Limitations
: Reduces frame rate
: Reduces temporal resolution
- Most effective with slow moving structures

(credit: https://minjikim-md.tistory.com/14)

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[Contents] 1. Preprocessing 2. Postprocessing 3. Persistence (Frame averaging) 4. Edge Enhancement 5. Spatial compounding 6. Panoramic Imaging 1. Preprocessing [★] 1) Manipulation of scan data befo..

# data[].attributes.body
1. Uses information obtained from several imaging angles to create one image.
- Averages frames obtained from different angles due to steering by employing time delays.
- Overlap frames to form a single real-time image

2. Help demonstrate tissue boundaries that are not perpendicular to sound beam

3. More frames = better image quality
- Reduces speckle, reduce refraction and enhancement
- Minimizes shadowing artifacts

4. Limitations
- Reduces frame rate (reducing temporal resolution)
- Electrical steering is used --> only in phased array transducers

(credit: https://minjikim-md.tistory.com/14)

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PACS, stands for Picture Archiving and Communications System, which describes the digital ultrasound laboratory in which images and additional medical information are digitized and stored on a large computer network. (pg. 259)

DICOM, stands for Digital Imaging and Computers in Medicine. DICOM is a set of rules, or protocols, that allows imaging systems to share information on a network.

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I wasn't able to add this picture in my first post but I wanted to share the difference between the two. I took these pictures last year! And you can see in the first post that picture is at the normal compression setting for a carotid scan, and there is a little bit of artifact shown in the artery. The second picture shows the compression knob being turned all the way to the left and the dynamic range changed, and the tiny piece of artifact has disappeared.

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Compression is a technique that reduces the dynamic range of a signal without introducing errors. (pg. 266)

Compression allows you to tell the ultrasound machine how you want the echo intensity displayed as shades of gray. A broad/wide range will be display more shades of gray and an overall smoother image. A smaller/narrow range will display fewer shades of gray and appear as a higher contrast with a more black-and-white image. (credit: https://www.providianmedical.com/ultrasound-imaging-guide/#dynamic-range)

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Scan converters are no longer used because the technology is out dated. Today, many machines use a flat screen digital display. Previously, the displays were the big, old-fashioned, boxy TV displays. These displays required the received data to be in an analog format to display. Scan converters change the incoming analog data from the transducer to a digital format that can then be changed back to another analog format suitable for display. The displays are now digital,  so the data is received from the transducer and changed into a digital format that can be displayed without the need of a scan converter.