What is the most reliable imaging modality for small colonic polyp characterization? Study of white-light, autofluorescence, and narrow-band imaging

Abstract

Of the imaging modalities tested, NBImag appeared to have the best overall accuracy and interobserver agreement, although not adequate for in vivo diagnosis. NBI and AFI did not have better sensitivity, specificity, or accuracy compared with WLE.

In vivo Optical Diagnosis of Polyp Histology: Can We Omit Pathological Examination of Diminutive Polyps?

“…The results of NBI without optical magnification in predicting histology are variable with authors showing an accuracy similar to that of optical magnification NBI and authors obtaining worse results [56]. Again, different definitions for a vascular pattern typical of adenoma (table 4) may account for these discrepancies.…”

“…Paggy et al [72] found similar results both in the whole group of < 10 mm polyps and in diminutive polyps. Other authors have not showed as good results [56,73]. The most recent report using the NICE classification found an accuracy of 89%, sensitivity of 98% and a NPV of 95%.…”

“…Three studies from the same group show a poor diagnostic accuracy for NBI without magnification and autofluorescence with similar sensitivity but worse specificity [59,63,64]. Ignjatovic et al [56] reported that NBI with magnification appeared to have the best accuracy, albeit modest and not adequate for in vivo diagnosis.…”

“…This heterogeneity may be explained by the use of different descriptions of vascular networks. Examples are, brown blob or dense vascular network to predict neoplasia [46][47][48]; fine capillary network, dark dots, light rounds, tubular or gyrus like [49]; microvessel thickness (invisible, thin, thick) and microvessel irregularity (invisible, regular, mildly irregular, severely irregular) [50]; vascular patter intensity (weaker, the same or darker than the surrounding mucosa) [51]; fine vascular network or dilated corkscrew type vessels and abnormal branching patterns [52]; and finally, capillary pattern (CP type I: invisible or faintly visible, CP type II: capillaries elongated and thicker and CP type III: capillaries of irregular sizes, thicker and branched) [53][54][55].Other causes of heterogeneity are the use of magnification or high-resolution endoscopes since the results with the latter are not as encouraging (see section 2.2.5) [46,49,56], and finally, better results are reported by experts.…”

Hyperspectral imaging fluorescence excitation scanning for colon cancer detection

“…There are currently several complementary endoscopic technologies for colorectal exams: white light endoscopy (WLE), narrow-band imaging, autofluorescence imaging, and chromoendoscopy. [5][6][7] Interestingly, although the specificity and sensitivity of these endoscopic technologies have been estimated in a range of studies, 3,5,6,[8][9][10][11] no single technology has emerged as clearly superior. As such, WLE remains the gold standard and is often the "de facto" imaging modality for colorectal screening.…”