Reconstruction filters and contrast detail curves in CT

W. Huda; K. M. Ogden; E. Samei; E. M. Scalzetti; R. L. Lavallee; M. L. Roskopf; G. E. Groat

doi:10.1117/12.770530

6 March 2008 Reconstruction filters and contrast detail curves in CT

W. Huda, K. M. Ogden, E. Samei, E. M. Scalzetti, R. L. Lavallee, M. L. Roskopf, G. E. Groat

Proceedings Volume 6917, Medical Imaging 2008: Image Perception, Observer Performance, and Technology Assessment; 691710 (2008) https://doi.org/10.1117/12.770530
Event: Medical Imaging, 2008, San Diego, California, United States

Abstract

In this study, we investigated the effect of CT reconstruction filters in abdominal CT images of a male anthropomorphic phantom. A GE Light Speed CT 4-slice scanner was used to scan the abdomen of an adult Rando phantom. Cross sectional images of the phantom were reconstructed using four reconstruction filters: (1) soft tissue with the lowest noise; (2) detail (relative noise 1.7); (3) bone (relative noise 4.5); and (4) edge (relative noise 7.7). A two Alternate Forced Choice (AFC) experimental paradigm was used to estimate the intensity needed to achieve 92% correct (i.e., I_92%). Four observers measured detection performance for five lesions with size ranging from 2.5 to 12.5 mm for each of these four reconstruction filters. Contrast detail curves obtained in images of an anthropomorphic phantom were not straight lines, but best fitted to a second order polynomial. Results from four readers show similar trends with modest inter-observer differences with the measured coefficient of variation of the absolute performance levels of ~22%. All reconstruction filters had similar shaped contrast detail curves except for smallest details where the frequency response of filters differed most significantly. Increasing the noise level always reduced detection performance, and a doubling of image noise resulted in an average drop in detection performance of ~20%. The key findings of this study are that (a) the Rose model can provide reasonable predictions as to how changes in lesion size affect observer detection; (b) the shape of CT contrast detail curves is affected only very slightly with reconstruction filter; (c) changes in reconstruction filter noise can predict qualitative changes in observer detection performance, but are poor direct predictors of the quantitative changes of imaging performance.

Citation Download Citation

W. Huda, K. M. Ogden, E. Samei, E. M. Scalzetti, R. L. Lavallee, M. L. Roskopf, and G. E. Groat "Reconstruction filters and contrast detail curves in CT", Proc. SPIE 6917, Medical Imaging 2008: Image Perception, Observer Performance, and Technology Assessment, 691710 (6 March 2008); https://doi.org/10.1117/12.770530

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available