Channelized hotelling observers for the detection of 2D signals in 3D simulated images

Current clinical practice is increasingly moving in the direction of volumetric imaging. However, model observers for 3D images have been little explored so far. This study is investigating the task of detecting 2D signals in multi-slice simulated image data. We propose a novel design of a multi-slice model observer. To evaluate it, we compare three different model designs of the channelized Hotelling observer (CHO), two multi-slice and one single-slice model. The multi-slice models are built as a sequence of a 2D CHO and 1D HO, where the CHO is used to calculate a vector of metrics for each slice in the planar view and the HO is used to calculate the final scalar statistic of the model. The single-slice model is a 2D CHO applied on the location of the lesion. Our results show that the multi-slice models outperform the single-slice one, and here the new model surpasses the existing one.