A Case Study in Pharmacologic Colon Imaging Using Principal Curves in Single-Photon Emission Computed Tomography

• Published in: Journal of the American Statistical Association Vol. 103; no. 484; pp. 1470 - 1480
• Main Authors: Caffo, Brian S., Crainiceanu, Ciprian M., Deng, Lijuan, Hendrix, Craig W.
• Format: Journal Article
• Language: English
• Published: Alexandria, VA Taylor & Francis 01.12.2008; American Statistical Association; Taylor & Francis Ltd
• Subjects: Algorithms; Anatomy; Applications; Applications and Case Studies; Colon; Computed tomography; Computerized axial tomography; Curve fitting; Degrees of freedom; Digital technology; Disease transmission; Distribution theory; Emission analysis; Emissions; Exact sciences and technology; General topics; HIV; Human immunodeficiency virus; Image processing; Imaging; Imaging techniques; In vivo methods and tests; Interior points; Lubricants; Lubricants & lubrication; Mathematics; Medical imaging; Molding; Pharmacology; Photon emission; Photons; Probability and statistics; Probability theory and stochastic processes; Regression analysis; Safe sexual practices; Sciences and techniques of general use; Smoothing; SPECT; Statistical methods; Statistics; Tomography; Human; Three-dimensional calculations; Experimental data; Medical imaging; Retroviridae; Pharmacology; Lentivirus; Algorithm; SPECT; Virus; Case study; Functional; Statistical method; Smoothing; Distribution function; Tomography; Two-dimensional calculations; Human immunodeficiency virus; Application; Curve fitting; Emission tomography
• ISSN: 0162-1459; 1537-274X
• DOI: 10.1198/016214508000000832

In this article we are concerned with functional imaging of the colon to assess the kinetics of microbicide lubricants. The overarching goal is to understand the distribution of the lubricants in the colon. Such information is crucial for understanding the potential impact of microbicides on human immunodeficiency virus transmission. The experiment was conducted by imaging a radiolabeled lubricant distributed in the subject's colon. The tracer imaging was conducted via single-photon emission computed tomography, a noninvasive, in vivo functional imaging technique. We have developed a novel principal curve algorithm to construct a three-dimensional curve through the colon images. The algorithm was tested and debugged on several difficult two-dimensional images of familiar curves where the original principal curve algorithm does not apply. The final curve fit to the colon data is compared with experimental sigmoidoscope collection.