Digital Radiography Artifacts

Artifacts

Undesirable optical densities or blemishes on a radiograph or any other medical image

Ghost Image

it happens when there's an incomplete erasure of a previous image on a CR IP

Ghost Image

caused by double exposure or environmental radiation

Interpolation

a process of assigning a value to a dead pixel based on the recorder value of adjacent pixels

Flat Fielding

software correction that is performed to equalize the response of each pixel to a uniform xray beam

2

what is the field size per image in nuclear medicine

5

what is the field size per image in MRI

10

What is the field size per image in computed tomography

20

what is the field size per image in CR and DR

50

what is the field size per image in digital mammography

Lossless compression

image that can be reconstructed to be exactly the same as the original

10% (10:1) to 50% (2:1)

lossless compression reduce the data file to _____ to _____ of the original file

Lossy Compression

it can provide compression up to 100:1 or greater, and can be used on images in which exact measurement or fine detail is not required

Archiving Mammography images

Lossy compression is not acceptable for archiving images of what kind?

Histogram

a graph of frequency of occurrence versus digital value intervals

Proper collimation and centering

These could help/prevent histogram errors that can lead to artifacts

properly collimated, sized and positioned

a exposure field recognition errors may occur if the xray exposure field is not ____________?