CT image quality assessment by a Channelized Hotelling Observer (CHO): Application to protocol optimization.

In this work we investigate the feasibility of employing a Channelized Hotelling model Observer (CHO) in a CT protocol optimization program with the aim at assuring that the scanners are working at their own best with regard to the quality of images and patient exposure. Although the benefit of using model observers in the clinical protocol optimization is evident, in the practice it is still to be investigated what are the pitfalls associated with this method. With this concern we focused on a clinical protocol for oncology of the abdomen. For the implementation of CHO, we designed a new phantom with the aim of minimizing the number of acquired images. After tuning the model according to a restricted data set, we applied it to the evaluation of a large data set of images obtained with different reconstruction algorithms and acquired on different scanners. Results were very encouraging about the usefulness of CHO for the mentioned purposes. For the first time, at our knowledge, the applicability of CHO was demonstrated for images reconstructed with both filtered back projection (FBP) and iterative (IR) algorithms on the same scanner as well as for images from different scanners, though produced by the same manufacturer. Instead it turned out that CHO was not applicable for the same purposes over images from another manufacturer.

[1]  Kyle J. Myers,et al.  Model observers for assessment of image quality , 1993 .

[2]  Damien Racine,et al.  Objective assessment of low contrast detectability in computed tomography with Channelized Hotelling Observer. , 2016, Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics.

[3]  W J H Veldkamp,et al.  Low contrast detectability performance of model observers based on CT phantom images: kVp influence. , 2015, Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics.

[4]  Shuai Leng,et al.  Correlation between model observer and human observer performance in CT imaging when lesion location is uncertain. , 2013, Medical physics.

[5]  Shuai Leng,et al.  Prediction of human observer performance in a 2-alternative forced choice low-contrast detection task using channelized Hotelling observer: impact of radiation dose and reconstruction algorithms. , 2013, Medical physics.

[6]  Jie Yao,et al.  Predicting human performance by a channelized Hotelling observer model , 1992, Optics & Photonics.

[7]  J Y Vaishnav,et al.  Objective assessment of image quality and dose reduction in CT iterative reconstruction. , 2014, Medical physics.

[8]  Charles E Metz,et al.  Receiver operating characteristic analysis: a tool for the quantitative evaluation of observer performance and imaging systems. , 2006, Journal of the American College of Radiology : JACR.

[9]  Yi Zhang,et al.  Correlation between human and model observer performance for discrimination task in CT , 2014, Physics in medicine and biology.

[10]  J. Robson,et al.  Spatial-frequency channels in human vision. , 1971, Journal of the Optical Society of America.

[11]  John Eng,et al.  Receiver operating characteristic analysis: a primer. , 2005, Academic radiology.

[12]  Junji Shiraishi,et al.  Modulation transfer function measurement of CT images by use of a circular edge method with a logistic curve-fitting technique , 2014, Radiological Physics and Technology.

[13]  John M. Boone,et al.  Radiation dose and image-quality assessment in computed tomography , 2012 .

[14]  H H Barrett,et al.  Addition of a channel mechanism to the ideal-observer model. , 1987, Journal of the Optical Society of America. A, Optics and image science.

[15]  Miguel P Eckstein,et al.  Evaluation of internal noise methods for Hotelling observer models. , 2007, Medical physics.

[16]  F O Bochud,et al.  Image quality in CT: From physical measurements to model observers. , 2015, Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics.

[17]  Jovan G Brankov,et al.  Evaluation of the channelized Hotelling observer with an internal-noise model in a train-test paradigm for cardiac SPECT defect detection , 2013, Physics in medicine and biology.

[18]  Kyle J Myers,et al.  CT image assessment by low contrast signal detectability evaluation with unknown signal location. , 2013, Medical physics.