Evaluation of various attenuation corrections in lung SPECT in healthy subjects
2003 (English)In: Nuclear medicine communications, ISSN 0143-3636, E-ISSN 1473-5628, Vol. 24, no 10, 1087-1095 p.Article in journal (Refereed) Published
The effect of increasingly more sophisticated attenuation correction methods on image homogeneity has been studied in seven healthy subjects. The subjects underwent computed tomography (CT), single photon emission computed tomography (SPECT) and transmission computed tomography (TCT) of the thorax region in the supine position. Density maps were obtained from the CT and TCT studies. Attenuation corrections were performed using five different methods: (1) uniform correction using only the body contour, (2) TCT based corrections using the average lung density, (3) TCT based corrections using the pixel density, (4) CT based corrections using average lung density, and (5) CT based corrections using the pixel density. The isolated attenuation effects were assessed on quotient images generated by the division of images obtained using various attenuation correction methods divided by the non-uniform attenuation correction based on CT pixel density (reference method). The homogeneity was calculated as the coefficient of variation of the quotient images (CVatt), showing the isolated attenuation effects. Values of CVatt were on average 12.8% without attenuation correction, 10.7% with the uniform correction, 8.1% using TCT map using the average lung density value and 4.8% using CT and average lung density corrections. There are considerable inhomogeneities in lung SPECT slices due to the attenuation effect. After attenuation correction the remaining inhomogeneity is considerable and cannot be explained by statistical noise and camera non-uniformity alone.
Place, publisher, year, edition, pages
2003. Vol. 24, no 10, 1087-1095 p.
attenuation correction, SPECT, lung and thorax region
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-47749DOI: 10.1097/00006231-200310000-00009OAI: oai:DiVA.org:liu-47749DiVA: diva2:268645