American Gastroenterological Association technical review on the management of Barrett's esophagus.

Purpose Most of the esophageal squamous cell carcinomas (ESCCs) and cancers of the head and neck (HN 97% v 55%, P < .001, respectively). The sensitivity ...

Early Detection of Superficial Squamous Cell Carcinoma in the Head and Neck Region and Esophagus by Narrow Band Imaging: A Multicenter Randomized Controlled Trial

The quality of images reconstructed by statistical iterative methods depends on an accurate model of the relationship between image space and projection space through the system matrix. The elements of the system matrix for the clinical Hi-Rez scanner were derived by processing the data measured for a point source at different positions in a portion of the field of view. These measured data included axial compression and azimuthal interleaving of adjacent projections. Measured data were corrected for crystal and geometrical efficiency. Then, a whole system matrix was derived by processing the responses in projection space. Such responses included both geometrical and detection physics components of the system matrix. The response was parameterized to correct for point source location and to smooth for projection noise. The model also accounts for axial compression (span) used on the scanner. The forward projector for iterative reconstruction was constructed using the estimated response parameters. This paper extends our previous work to fully three-dimensional. Experimental data were used to compare images reconstructed by the standard iterative reconstruction software and the one modeling the response function. The results showed that the modeling of the response function improves both spatial resolution and noise properties

Fully 3-D PET reconstruction with system matrix derived from point source measurements

A combination of targeted probes and new imaging technologies provides a powerful set of tools with the potential to improve the early detection of cancer. To develop a probe for detecting colon cancer, we screened phage display peptide libraries against fresh human colonic adenomas for high-affinity ligands with preferential binding to premalignant tissue. We identified a specific heptapeptide sequence, VRPMPLQ, which we synthesized, conjugated with fluorescein and tested in patients undergoing colonoscopy. We imaged topically administered peptide using a fluorescence confocal microendoscope delivered through the instrument channel of a standard colonoscope. In vivo images were acquired at 12 frames per second with 50-μm working distance and 2.5-μm (transverse) and 20-μm (axial) resolution. The fluorescein-conjugated peptide bound more strongly to dysplastic colonocytes than to adjacent normal cells with 81% sensitivity and 82% specificity. This methodology represents a promising diagnostic imaging approach for the early detection of colorectal cancer and potentially of other epithelial malignancies.

Detection of colonic dysplasia in vivo using a targeted heptapeptide and confocal microendoscopy

Several attacks are proposed against the double random phase encryption scheme. These attacks are demonstrated on computer-generated ciphered images. The scheme is shown to be resistant against brute force attacks but susceptible to chosen and known plaintext attacks. In particular, we describe a technique to recover the exact keys with only two known plain images. We compare this technique to other attacks proposed in the literature.

Resistance of the double random phase encryption against various attacks

This study was performed to examine the usefulness of medical endoscopic imaging utilizing narrow-band illumination. The contrast between the vascular pattern and the adjacent mucosa of the underside of the human tongue was measured using five narrow-band illuminations and three broadband illuminations. The results demon- strate that the pathological features of a vascular pattern are depen- dent on the center wavelength and the bandwidth of illumination. By utilizing narrow-band illumination of 415630 nm, the contrast of the capillary pattern in the superficial layer was markedly improved. This is an important benefit that is difficult to obtain with ordinary broad- band illumination. The appearances of capillary patterns on color im- ages were evaluated for three sets of filters. The narrow, band imaging (NBI) filter set (415630 nm, 445630 nm, 500630 nm) was selected to achieve the preferred appearance of the vascular patterns for clini- cal tests. The results of clinical tests in colonoscopy and esophagos- copy indicated that NBI will be useful as a supporting method for observation of the endoscopic findings of early cancer. © 2004 Society of

https://www.spiedigitallibrary.org/journals/Journal-of-Biomedical-Optics/volume-9/issue-03/0000/Appearance-of-enhanced-tissue-features-in-narrow-band-endoscopic-imaging/10.1117/1.1695563.pdf

Appearance of enhanced tissue features in narrow-band endoscopic imaging.

We propose a new illumination method for a medical endoscope: narrow band imaging (NBI), in which the spectral bandwidth of the filtered light is narrowed. To confirm how the spectral specifications of the filtered light influence a reproduced image, an experiment was conducted observing the endoscopic images of the back mucosa of a human tongue. In addition, the effect of NBI on endoscopic images was investigated through preliminary clinical tests in colonoscopy and upper gastrointestinal endoscopy. It has been shown that NBI can enhance the capillary pattern and the crypt pattern on the mucosa. These patterns are useful features for diagnosing an early cancer.

Endoscopic observation of tissue by narrowband illumination

A color image processing apparatus reproduces color data of a subject at higher accuracy by estimating the spectral reflectance of the subject from the color chip basis function vn (λ) which can expand the spectral reflectances of all color chips of the reference chart and the expansion coefficients B of the color chips The color image processing apparatus uses an image processing device to which a subject shooting signal Q shot by the color image input device and a reference chart shooting signal G taken from a plurality of color chips each having a spectral reflectance, is known

Color image processing apparatus

In a color reproduction device, an input profile that is referenced in converting an input image from an image input device into a device-independent color image is created based on image input device information, shooting- and observation-time lighting data, and subject data, allowing accurate conversion of the input image to the device-independent color image. In reproducing the image by an image output device, the spectral reflectance of the subject itself is calculated from image input device information and shooting-time lighting data, thereby reducing the effect of the shooting-time lighting. The colors of the subject under observation lighting are calculated from observation-time lighting data. A color reproduced image is estimated accurately on the basis of the subject data even if the input image has little information.

Color reproducing device

The range of the reproducible color, i.e., color gamut, of the conventional display devices such as CRTs (cathode ray tubes) and LCDs (liquid crystal displays) is sometimes insufficient for reproducing the natural color of an object through color imaging systems. In this paper, six-primary color display is presented to reproduce the expanded color gamut, by using two conventional RGB projectors and six interference filters. The design method of the filters is also introduced to maximize the volume of the color gamut in CIE-LUV uniform color space. Using the experimental system, the gamut of the six-primary projection display is evaluated comparing with that of conventional CRTs and projectors.

Takashi Obi

Papers

Appearance of enhanced tissue features in narrow-band endoscopic imaging.

Endoscopic observation of tissue by narrowband illumination

Color image processing apparatus

Color reproducing device

Expanded color gamut reproduced by six-primary projection display