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At least 127 records · Page 7Linked to original sources
PubMed1986

Success rates of blind orotracheal intubation using a transillumination technique with a lighted stylet.

The technique of guided orotracheal intubation using a lighted stylet depends on the transillumination of the soft tissues of the neck to direct the tube through the glottis and into the trachea. We conducted an operating room study of this technique, recording success rates and intubation times of 50 patients undergoing elective surgery. All patients were intubated successfully, 35 of 50 (70%) on the first attempt, 12 of 15 (80%) on the second attempt, and three of three (100%) on the third attempt. The average time for intubation was 37 seconds. A new design of the lighted stylet method resulted from the experience gained. Intubator training and experience influenced initial success rates, and the cadaver laboratory was of particular value in teaching the technique.

Adolescent↗
PubMed2001

The use of fibre-optic transillumination in general dental practice.

OBJECTIVE: To assess the use of fibre-optic transillumination (FOTI) as a diagnostic tool in general dental practice. DESIGN: A cross-over quantitative study for the diagnosis of approximal carious lesions by two clinical methods with a qualitative component. SUBJECTS AND METHODS: Seven GDPs were trained to use FOTI as an adjunct to their usual clinical examination to diagnose approximal caries. After 12 weeks of use in their practices four of the GDPs took part in two assessment sessions, set a week apart, using 29 volunteer patients. Each patient was examined on two separate occasions by each GDP using either their standard clinical examination technique alone or supplemented by FOTI examination. The order of the techniques was randomised. Radiographs of each patient were also examined separately. An experienced FOTI user also examined the patients to provide a benchmark. From standard charts the number of enamel and dentinal lesions on approximal surfaces was summed and comparisons made between the techniques. Six GDPs took part in one-to-one interviews. MAIN OUTCOME MEASURES: Mean numbers ofcarious lesions recorded by each clinician using each technique. RESULTS: There was a trend for all GDPs to find more enamel and dentinal lesions using FOTI, than with their standard clinical examination with or without radiographs. All GDPs found the FOTI technique a useful adjunct. They used FOTI in different ways and found a variety of uses for it other than caries diagnosis. CONCLUSIONS: The

Cross-Over Studies↗
PubMed2003

Hook phlebectomy versus transilluminated powered phlebectomy for varicose vein surgery: early results.

OBJECTIVES: to compare Transilluminated Powered Phlebectomy (TIPP) (TriVex System) with Muller's hook phlebectomy. MATERIALS AND METHODS: between January and April 2001, 40 patients (group 1) undergoing TIPP were non-randomly compared to 40 patients undergoing Muller's hook phlebectomy (group 2) in the course of conventional vein stripping and perforator ligation. All patients had at least C2 CEAP disease. RESULTS: hospital stay averaged 2 days (range 1-3 days; median 2 days) and was similar for the two groups. TIPP took significantly longer (56+/-12 vs 45+/-10 min, p<0.001) but was associated with significantly fewer incisions (6 [2-8] vs 8 [4-21], p<0.001). The mean pain score (out of 10) at 2 and 7 days and 6 weeks was 5, 2 and zero after TIPP and 4, 2 and zero after hook phlebectomy. The incidence of postoperative haematoma formation was significantly higher after TIPP (45 vs 25%, p=0.06), especially in the calf region (25 vs 2.5%,p =0.003). CONCLUSION: TIPP was slower (although speed increased with practice) associated with more haematoma (although this reduced with practice) and fewer incisions. In other respects (pain, cosmetic satisfaction, other complications, residual varices) it was not significantly different from hook phlebectomy. Greater clinical experience with the technique and randomized studies are required to determine whether TIPP is a valuable addition to our armamentarium.

Adult↗
PubMed2002

Spatial resolution in fast time-resolved transillumination imaging: an indeterministic Monte Carlo approach.

The spatial resolution achievable in time-resolved optical transillumination imaging through a turbid (scattering and absorbing) medium has been reassessed theoretically. The temporal point spread function was constructed assuming a delta function input pulse, a approximately 50 mm thick medium and a small detector with zero risetime. Temporal profiles were derived from an indeterministic Monte Carlo simulation for different time scales. From the temporal point spread function (TPSF), an analytic edge response function from which the spatial resolution was determined was derived. Previous analytical methods for determining the spatial resolution are approximations for very short flight times (sub-100 ps time region). The results show that a spatial resolution of about two millimetres is possible under ideal signal-to-noise ratio conditions and with detector gate times of the order of ten picoseconds. If this predicted spatial resolution can be achieved in an imaging system, it may be possible to improve the diagnosis of breast tumours.

Algorithms↗
PubMed2004

First photon detection in time-resolved transillumination imaging: a theoretical evaluation.

First photon detection, as a special case of time-resolved transillumination imaging, is studied through the derivation of the temporal probability density function (pdf) for the first arriving photon. The pdf for different laser intensities, media and second and later arriving photons were generated. The arrival time of the first detected photon reduced as the laser power increased and also when the scattering and absorption coefficients decreased. The pdf for an imbedded totally absorbing 3 mm inhomogeneity may be distinguished from the pdf of a homogeneous turbid medium similar to that of human breast in dimensions and optical properties.

Algorithms↗
PubMed1997

Wavelet representations for monitoring changes in teeth imaged with digital imaging fiber-optic transillumination.

Digital imaging fiber-optic transillumination (DI-FOTI) is a novel method to detect and monitor dental caries, using light, a charge-coupled device (CCD) camera, and computer-controlled image acquisition. The advantages of DIFOTI over radiography include: no ionizing radiation, no film, real-time diagnosis, and higher sensitivity in detection of early lesions not apparent to X-ray, as demonstrated in vitro. Here, we present a method of processing DIFOTI images, acquired at different times, for monitoring changes. Of central importance to this application is pattern matching of image frames that is invariant to translation and rotation of a tooth, relative to the field of view of the imaging camera, and that is robust to changes in illumination source intensity. Our method employs: 1) wavelet modulus maxima representations for segmentation of teeth images; 2) first and second moments of gray level representations of DIFOTI images in the spatial domain, to estimate tooth location and orientation; and 3) multiresolution wavelet magnitude representations for quantitative monitoring. Even with illumination source intensity variation, it is demonstrated in vitro that such wavelet representations can facilitate detection of simulated clinical changes in light transmission that cannot be detected in the spatial domain.

Algorithms↗
PubMed1987

Comparison of fibre optic transillumination with clinical and radiographic caries diagnosis.

Fibre optic transillumination (FOTI) has been employed during the course of a 3-yr clinical dentifrice trial which initially involved 3003 children. At the initial examination, a subgroup of 813 13-yr-olds, and at the following annual visit, 2247 14-yr-olds, were examined using a 150 W lamp and 0.5 mm diameter probe. Routine clinical and radiographic examinations were performed separately. Compared to the clinical scores for anterior teeth, FOTI detected an additional 64% of interproximal lesions at the first visit while, for the larger number of children at the second visit, the increase in lesion detection level using FOTI was 37%. For the posterior teeth the comparable figure at the second examination was 92%. When FOTI data were compared to radiographic data for more than 52,000 posterior interproximal surfaces, FOTI could only detect 17% of radiographic Grade 2 lesions and 48% Grade 3 lesions. Thus any assumption that FOTI diagnoses may be a substitute for bitewing radiography appears premature.

Adolescent↗
PubMed2004

Classification of breast tissue density by optical transillumination spectroscopy: optical and physiological effects governing predictive value.

Preventive oncology is in need of a risk assessment technique that can identify individuals at high risk for breast cancer and has the ability to monitor the efficacy of a risk reducing intervention. Optical transillumination spectroscopy (OTS) gives information about breast tissue composition and tissue density. OTS is noninvasive and in contrast to mammography, uses nonionizing radiation. It is safe and can be used frequently on younger women, potentially permitting early risk detection and thus increasing the time available for risk reduction interventions to assert their influence. Before OTS can be used as a risk assessment and/or monitoring technique, its predictive ability needs to be demonstrated and maximized through the construction of various mathematical models relating OTS and breast tissue density, and hence, risk. To establish a correlation between OTS and mammographic density principal components analysis (PCA), using risk classification, is calculated. The PCA scores are presented in three-dimensional cluster plots and a plane of differentiation that separates the high and low tissue densities is used to calculate the predictive value. Stratification of PCA for measurement position on the breast in cranial-caudal projection is introduced. Analysis of PCA scores as a function of the volunteer's age and body mass index (BMI) is examined. A small but significant correlation between the component scores and age or BMI is noted but the correlation is dependent on the tissue density category examined. Correction of the component scores for age and BMI is not recommended, since a priori knowledge of a woman's breast tissue density is required. Stratification for the center and distal measurement positions provide a predictive value for OTS above 96%.

Adult↗
PubMedDate not supplied

Transillumination imaging performance: a time-of-flight imaging system.

A series of Monte Carlo simulations have been performed in order to investigate the feasibility of constructing a time-of-flight transillumination imaging system that could be used as an effective tool for screening for breast disease. The conceptual design of such a system is described, and simulated images are presented that demonstrate its likely performance. It is found that, whereas the spatial resolution achievable with such a system is only dependent upon its temporal resolution, the scattering characteristics of the tissue being imaged will strongly affect the ultimate imaging performance of such a system.

Breast Neoplasms↗
PubMedDate not supplied

Transillumination imaging performance: spatial resolution simulation studies.

Monte Carlo calculations were used to simulate the propagation of visible and near-infrared light through homogenous tissue in order to quantitate the potential spatial resolution performance for transillumination imaging. Specifically, the relative effectiveness of coaxial collimation and time of flight (TOF) detection for improving spatial resolution was investigated. The results demonstrate that significant improvements in spatial resolution can be achieved through these techniques, with TOF methods offering superior performance for a given level of detected signal intensity.

Computer Simulation↗
PubMed1994

Resolution limits for optical transillumination of abnormalities deeply embedded in tissues.

Random walk theory is used to calculate the line spread function (LSF) of photons as they cross the midplane of a slab of finite thickness. The relationship between the LSF and the photon transit time in transillumination time-resolved experiments is investigated. It is found that the LSF is approximately Gaussian distributed, with a standard deviation, sigma, which can be used as a criterion of the spatial resolution of the imaging system. Results are substantiated by comparison with actual data in the literature. Any given resolution can be improved by reducing the excess transit time delta t, but heterogeneity of the scattering medium and low levels of detected light enormously complicate the achievement of subcentimeter spatial resolution. The latter point is discussed by using optical parameters of breast tissues for visible and near-infrared radiation (NIR) light.

Breast Diseases↗
PubMed1996

Point spread functions of photons in time-resolved transillumination experiments using simple scaling arguments.

Simple scaling arguments are used to determine spatial resolution achievable in time-resolved transillumination experiments involving highly diffuse media. These arguments allow us to obtain relationships linking target resolution at different planes inside an optically turbid slab to the gating times of the imaging system. We show that this approach yields the same results as those obtained previously from an approximate and rather complicated analytical derivation. In addition, we are now able to assess the effects of scattering anisotropy on spatial resolution attainable when gating times are so short that a constant scaling of photon transport scattering length is not appropriate. These results should enable one to devise more accurate and simpler image reconstruction algorithms.

Algorithms↗
PubMed1997

Computer simulation of time-gated transillumination and reflection of biological tissues and tissuelike phantoms.

A simulation technique is employed to explore the possibility of locating millimeter-sized objects, immersed in turbid media, from time-gated measurements of the transmitted or reflected light. The simulation results for tissuelike phantoms are compared to experimental transillumination data and excellent agreement is found. Simulations of time-gated reflection experiments show that it is possible to detect objects of 1 mm diameter. This may open new possibilities for medical diagnosis of breast cancer in an early stage.

Algorithms↗
PubMed1978

Percutaneous catheterisation of the radial artery in newborn babies using transillumination.

A technique for inserting radial artery catheters percutaneously in newborn babies using transillumination is described. Catheterisation was successful in 69% of the 107 babies in whom it was attempted. In the last 30 attempts there was an 85% success rate with an average useful life of 100 hours. The average weight of these babies was 1405 g, with a range of 620--4250 g. The method has several advantages over previous methods.

Arteries↗
PubMed1983

Transillumination of breast tissues: factors governing optimal imaging of lesions.

Lesions within the female breast may be observed in a darkened room when the tissues are transilluminated by white light. Telediaphanography is a method of recording that can reproduce images of lesions in monochrome or pseudocolor in real time. A model system is described that permits measurement of spatial resolution.

Breast Neoplasms↗
PubMed1998

Reliability of visual examination, fibre-optic transillumination, and bite-wing radiography, and reproducibility of direct visual examination following tooth separation for the identification of cavitated carious lesions in contacting approximal surfaces.

The aim of this study was to evaluate the diagnostic accuracy of visual, fibreoptic transillumination (FOTI), and bite-wing radiographic examination performed by 4 observers for the identification of cavitated carious lesions in contacting approximal surfaces, and to assess the inter-observer agreement with these methods and with direct visual examination conducted after tooth separation, the method used as validation for definitive determination of cavitation. A total of 338 unrestored approximal surfaces in 53 students were examined independently by 4 dentists using the diagnostic methods under study. The results from the diagnostic methods were compared with the results from the validation method for each observer. The sensitivities for identification of cavitated lesions using visual examination ranged from 0.12 to 0.50. For FOTI and radiography, the sensitivities ranged from 0.00 to 0.08 and from 0.56 to 0.69, respectively. The specificities exceeded 0.90 for all observers with all methods. Kappa values expressing inter-observer reproducibility were lowest for FOTI, followed by visual and radiographic examination. On the basis of these results, it was concluded that FOTI was the least reliable of the diagnostic methods tested. For the validation method, the inter-observer agreement was only 'substantial'. This implies that the method cannot be used as a validation for other diagnostic methods applied for the identification of cavitated carious lesions in contacting approximal surfaces. However, visual inspection after tooth separation may serve as a supplementary diagnostic tool to conventional visual and radiographic examination for clinical management of aproximal carious lesions.

Adult↗
PubMedDate not supplied

An in vitro comparison of the ability of fibre-optic transillumination, visual inspection and radiographs to detect occlusal caries and evaluate lesion depth.

The aim of this study was to compare the performance of fibre-optic transillumination (FOTI), visual inspection and bite-wing radiographs to detect occlusal caries and estimate the lesion depth. Fifty-nine extracted molars were assessed using FOTI and visual examination by 4 trained examiners and 1 examiner evaluated the bite-wing radiographs. Histological validation was performed using 250-microm sections examined with a stereomicroscope. For the three methods, the correlation between the lesion depth and the histological scores varied from 0.65 to 0.73. For dentinal caries detection, the areas under ROC curves ranged from 0.83 to 0.87. The radiographic method was poor at detecting lesions confined to enamel. FOTI, visual inspection and radiographs showed a good correlation with the histology but had difficulty in distinguishing lesions located deep in enamel or in the outer third of dentine. FOTI was shown to be as accurate as a detailed visual inspection in detecting occlusal caries.

Dental Caries↗
PubMed1993

Validity and reproducibility of clinical examination, fibre-optic transillumination, and bite-wing radiology for the diagnosis of small approximal carious lesions: an in vitro study.

This study measured validity and reproducibility of unaided clinical diagnosis, fibre-optic transillumination (FOTI), and bite-wing radiology in the diagnosis of approximal caries. Sixty models were made using extracted premolars and molars, each containing four teeth with six contacting approximal surfaces. The teeth were examined first using unaided clinical examination and then using FOTI. Bite-wing radiographs were then taken of the teeth set in the models and examined. The three examinations were repeated after 1 week. Histological sections of the undecalcified teeth were prepared following their removal from the models, and those showing signs of caries were examined to give the valid state of disease in each surface. The diagnostic threshold was caries penetrating into dentine. The reproducibility of all three methods was acceptable with kappa values exceeding 0.6. All specificity values exceeded 0.95. Statistically significant differences were seen between sensitivities for clinical (0.38) and bite-wing (0.59) diagnosis and between clinical and FOTI (0.67) examination, but not between bite-wing and FOTI. It is concluded that the validity of FOTI is at least as high as that of bite-wing radiology, and both are superior to unaided clinical diagnosis.

Bicuspid↗