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Göteborgs universitets publikationer

Shape determination of microcalcifications in simulated digital mammography images with varying pixel size

Författare och institution:
M. Ruschin (-); Magnus Båth (Institutionen för särskilda specialiteter, Avdelningen för radiofysik); B. Hemdal (-); A. Tingberg (-)
Publicerad i:
Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 5749 s. 288-299
ISSN:
1605-7422
Publikationstyp:
Artikel, övrig vetenskaplig
Publiceringsår:
2005
Språk:
engelska
Fulltextlänk:
Sammanfattning (abstract):
The purpose of this work was to study how the pixel size of digital detectors can affect shape determination of microcalcifications in mammography. Screen-film mammograms containing microcalcifications clinically proven to be indicative of malignancy were digitised at 100 lines/mm using a high-resolution Tango drum scanner. Forty microcalcifications were selected to cover an appropriate range of sizes, shapes and contrasts typically found of malignant cases. Based on the measured MTF and NPS of the combined screen-film and scanner system, these digitised images were filtered to simulate images acquired with a square sampling pixel size of 10 μm × 10 μm and a fill factor of one. To simulate images acquired with larger pixel sizes, these finely sampled images were re-binned to yield a range of effective pixel sizes from 20 μm up to 140 μm. An alternative forced-choice (AFC) observer experiment was conducted with eleven observers for this set of digitised microcalcifications to determine how pixel size affects the ability to discriminate shape. It was found that observer score increased with decreasing pixel size down to 60 μm (p<0.01), at which point no significant advantage was obtained by using smaller pixel sizes due to the excessive relative noise-per-pixel. The relative gain in shape discrimination ability at smaller pixel sizes was larger for microcalcifications that were smaller than 500 μm and circular.
Ämne (baseras på Högskoleverkets indelning av forskningsämnen):
MEDICIN OCH HÄLSOVETENSKAP ->
Klinisk medicin ->
Radiologi och bildbehandling ->
Radiologi
MEDICIN OCH HÄLSOVETENSKAP ->
Klinisk medicin ->
Radiologi och bildbehandling ->
Radiofysik
Nyckelord:
Digital mammography , Image restoration , Microcalcification , Pixel size , Shape
Postens nummer:
235496
Posten skapad:
2016-04-28 17:42

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