Orally administered tagging agents are usually used in CT colonography (CTC) to differentiate residual bowel content
from native colonic structure. However, the high-density contrast agents tend to introduce the scatter effect on
neighboring soft tissues and elevate their observed CT attenuation values toward that of the tagged materials (TMs),
which may result in an excessive electronic colon cleansing (ECC) where pseudo-enhanced soft tissues are incorrectly
identified as TMs. To address this issue, we integrated a scale-based scatter correction as a preprocessing procedure into
our previous ECC pipeline based on the maximum a posteriori expectation-maximization (MAP-EM) partial volume
segmentation. The newly proposed ECC scheme takes into account both scatter effect and partial volume effect that
commonly appear in CTC images. We evaluated the new method with 10 patient CTC studies and found improved
performance. Our results suggest that the proposed strategy is effective with potentially significant benefits for both
clinical CTC examinations and automatic computer-aided detection (CAD) of colon polyps.
The Feldkamp (FDK) algorithm is the most popular algorithm for circular cone-beam computed tomography (CBCT).
While, due to the spatially invariant interpolation process and pre-weighting factor adopted in numerical implementation
of the algorithms, non-uniform noise propagation have been observed across the field-of-view. In this study, instead of
using spatially invariant interpolation, we consider the spatially variant weighting to compensate for the non-uniformity.
The simulation study demonstrates the effectiveness of the presented solution.
Human colon has complex structures since it turns, twists, and even mobiles when the position of patient changes. The
awareness of the locations and orientations is very important for improving the experience of virtual navigation,
registration of supine/prone images and polyp matching. Teniae coli (TCs) are three longitudinal muscles along the
human colon. They are parts of the colon wall, and they have the potential to serve as reliable landmarks to provide the
above mentioned awareness. Morphologically, TCs are three smooth narrow bands, approximately perpendicular to the
haustral folds, and extending between the fold pairs in a parallel manner. Such characteristics make the TCs detectable
if the folds have been extracted already. In this study, based on the previous work of the segmentation of haustral folds,
we introduce a new method of automatically detecting the three TCs. The experiments will be conducted on real patient
studies to demonstrate the feasibility of the method, and solid evaluation will be conducted based on a flattened two-dimensional
(2D) colon representation.