Polyp height and width measurement using topographic height map

Yao, Jianhua; Frentz, Suzanne M.; Li, Jiang; Summers, Ronald M.

doi:10.1117/12.769463

Cited by 3 publications

(4 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These methods assessed polyp width or a combination of width and height, but not height alone, since the focus was to obtain a measurement comparable to the size measurements determined at optical colonoscopy. The height map algorithm used in this paper was tested on 226 polyps and found to agree well with manual assessment of polyp height [7, 8]. …”

Section: Discussionmentioning

confidence: 96%

“…To assess flatness, the heights of the polyps at CTC were measured using a validated automated software program [7, 8]. The program uses a topographical height map to locate the base of the polyp and then computes the height as the perpendicular distance from the base to the tip of the polyp.…”

Section: Methodsmentioning

confidence: 99%

“…Using a validated automated quantitative assessment of polyp height and width, we determined whether hyperplastic colonic polyps on CTC are objectively flatter than adenomatous polyps of comparable width [7, 8]. …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Automated Measurement of Colorectal Polyp Height at CT Colonography: Hyperplastic Polyps Are Flatter Than Adenomatous Polyps

Summers

Liu

Yao

et al. 2009

American Journal of Roentgenology

Self Cite

View full text Add to dashboard Cite

Objective It is known that hyperplastic polyps are more difficult to detect than adenomatous polyps at CT colonography (CTC) and it has been theorized that this is because hyperplastic polyps are flatter. Using automated software that computes polyp height, we determined whether hyperplastic colonic polyps on CTC are indeed flatter than adenomatous polyps of comparable width. Materials and Methods 1186 screening patients at 3 medical centers underwent oral contrast-enhanced CTC and same-day optical colonoscopy (OC) with segmental unblinding. 185 of the patients had at least one hyperplastic or adenomatous polyp 6–10 mm in size visible at CTC, where size was determined by a calibrated guidewire at OC. To assess flatness, the heights of the polyps at CTC were measured using a validated automated software program. Heights and height-to-width ratios of the hyperplastic polyps were compared to those of the adenomatous polyps using a t-test (two-tailed, unpaired, unequal variance). Results There were 176 adenomatous and 83 hyperplastic polyps visible at segmentally unblinded OC. The fraction of these polyps that were measurable at CTC using the automated software was not significantly different for adenomatous versus hyperplastic polyps (158/176, 89.8% versus 73/83, 83.9%, p=0.2). The average height-to-width ratios using automated width measurements were 15% less for hyperplastic polyps: 0.39±0.20 (n=158) and 0.33±0.19 (n=73) for adenomatous and hyperplastic polyps, respectively (p=0.03). When polyps of comparable OC size or CTC width were considered, the heights of hyperplastic polyps were up to 27% less than those of adenomatous polyps. Conclusions For 6–10 mm polyps of a given size as determined by optical colonoscopy or a given width at CT colonography, hyperplastic polyps tend to be flatter (i.e., have lower height) compared to adenomatous polyps.

show abstract

Section: Discussionmentioning

confidence: 96%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Automated Measurement of Colorectal Polyp Height at CT Colonography: Hyperplastic Polyps Are Flatter Than Adenomatous Polyps

Summers

Liu

Yao

et al. 2009

American Journal of Roentgenology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Some initial results from this paper were previously published in two conference papers [22] [23]. In this paper, we improve our technique by introducing virtual flattening techniques, and new topographic features based on principal component analysis.…”

Section: Introductionmentioning

confidence: 99%

Employing topographical height map in colonic polyp measurement and false positive reduction

Yao¹,

Li²,

Summers³

2009

Pattern Recognition

Self Cite

View full text Add to dashboard Cite

CT Colonography (CTC) is an emerging minimally invasive technique for screening and diagnosing colon cancers. Computer Aided Detection (CAD) techniques can increase sensitivity and reduce false positives. Inspired by the way radiologists detect polyps via 3D virtual fly-through in CTC, we borrowed the idea from geographic information systems to employ topographical height map in colonic polyp measurement and false positive reduction. After a curvature based filtering and a 3D CT feature classifier, a height map is computed for each detection using a ray-casting algorithm. We design a concentric index to characterize the concentric pattern in polyp height map based on the fact that polyps are protrusions from the colon wall and round in shape. The height map is optimized through a multi-scale spiral spherical search to maximize the concentric index. We derive several topographic features from the map and compute texture features based on wavelet decomposition. We then send the features to a committee of support vector machines for classification. We have trained our method on 394 patients (71 polyps) and tested it on 792 patients (226 polyps). Results showed that we can achieve 95% sensitivity at 2.4 false positives per patient and the height map features can reduce false positives by more than 50%. We compute the polyp height and width measurements and correlate them with manual measurements. The Pearson correlations are 0.74 (p=0.11) and 0.75 (p=0.17) for height and width, respectively.

show abstract

A CAD of fully automated colonic polyp detection for contrasted and non-contrasted CT scans

2017

View full text Add to dashboard Cite

show abstract

Polyp height and width measurement using topographic height map

Cited by 3 publications

References 6 publications

Automated Measurement of Colorectal Polyp Height at CT Colonography: Hyperplastic Polyps Are Flatter Than Adenomatous Polyps

Automated Measurement of Colorectal Polyp Height at CT Colonography: Hyperplastic Polyps Are Flatter Than Adenomatous Polyps

Employing topographical height map in colonic polyp measurement and false positive reduction

A CAD of fully automated colonic polyp detection for contrasted and non-contrasted CT scans

Contact Info

Product

Resources

About