Search results for "specificity"
showing 10 items of 2234 documents
Remote estimation of blood pulse pressure via temporal tracking of reflected secondary speckles pattern
2011
We present a novel technique for remote noncontact blood pulse pressure measurement. It is based on tracking both temporal and amplitude changes of reflected secondary speckle produced in human skin when illuminated by a laser beam. The implemented technique extracts the difference between the systolic and the diastolic blood pressure. Experimental results are presented showing good agreement when compared with conventional measurement methods.
Assessment of the fundamental flexural guided wave in cortical bone by an ultrasonic axial-transmission array transducer
2013
Abstract The fundamental flexural guided wave (FFGW), as modeled, for example, by the A0 Lamb mode, is a clinically useful indicator of cortical bone thickness. In the work described in this article, we tested so-called multiridge-based analysis, based on the crazy climber algorithm and short-time Fourier transform, for assessment of the FFGW component recorded by a clinical array transducer featuring a limited number of elements. Methods included numerical finite-element simulations and experiments in bone phantoms and human radius specimens ( n = 41). The proposed approach enabled extraction of the FFGW component and determination of its group velocity. This group velocity was in good ag…
High sensitivity of free lambda and free kappa light chains for detection of intrathecal immunoglobulin synthesis in cerebrospinal fluid.
2008
Background – So far, an inflammation of the central nervous system (CNS) is diagnosed by immunoglobulin measurement in cerebrospinal fluid (CSF) and serum as well as by determination of the oligoclonal bands. With the free kappa and lambda light chains, new markers to diagnose intrathecal synthesis are available. Methods – In addition to routine diagnostic tests and the assessment of standard parameters, free immunoglobulin light chains were measured in the CSF of patients with neurological disorders. Results – A significant agreement was found between an increase in free kappa light chain CSF serum quotients and results of the currently widely applied method of oligoclonal band measurem…
Laser fragmentation of pancreatic duct stones using a rhodamine laser with an automatic stone-tissue detection system. Basic in-vitro studies
1997
OBJECTIVES The aim of our study was to examine the suitability of a rhodamine 6G laser with an integrated stone-tissue detection system (STDS) for fragmenting pancreatic stones. METHODS A total of 64 pancreatic duct stones were measured for weight, diameter, main chemical components and in some cases for their computerized tomography density. Recognition of all stones was checked with the standard STDS or a prototype version. Number of fragmentation pulses, total fragmentation energies and correlation with the individual stone parameters were determined. The quality of the tissue-detection mode was evaluated in postmortem pancreata. RESULTS The standard STDS detected only 45% of the pancrea…
Validity of needle core biopsy in the histological characterisation of mammary lesions
2006
Summary Over the last few years, there has been an enormous increase in the use of needle core biopsy (CB) for the histopathological characterisation of suspect lesions of the breast. The aim of this study was to verify the diagnostic reliability of CB by comparing the histological results obtained with the use of this technique with those obtained from the whole of the surgically resected specimen. We studied 198 out of 426 patients with clinically and/or radiologically suspect breast lesions. We found correspondence between the histological examination of the whole of the excised specimen and that of the CB in 94.9% of the cases of infiltrating carcinoma and in 71.4% of those involving du…
Hyperspectral imaging reveals spectral differences and can distinguish malignant melanoma from pigmented basal cell carcinomas : A pilot study
2021
Pigmented basal cell carcinomas can be difficult to distinguish from melanocytic tumours. Hyperspectral imaging is a non-invasive imaging technique that measures the reflectance spectra of skin in vivo. The aim of this prospective pilot study was to use a convolutional neural network classifier in hyperspectral images for differential diagnosis between pigmented basal cell carcinomas and melanoma. A total of 26 pigmented lesions (10 pigmented basal cell carcinomas, 12 melanomas in situ, 4 invasive melanomas) were imaged with hyperspectral imaging and excised for histopathological diagnosis. For 2-class classifier (melanocytic tumours vs pigmented basal cell carcinomas) using the majority of…
Relation of elastosis to biochemical and immunohistochemical steroid receptor findings, Ki-67 and epidermal growth factor receptor (EGFR) immunostain…
1993
We studied 1073 cases of invasive ductal breast cancer, NOS for their elastic content (DEL, ductal+periductal elastosis; TEL, tumour elastosis) and compared the findings with the results of biochemical and immunohistochemical steroid hormone receptor examination. Tumours of patients up to 50 years of age and older were examined separately. In a number of tumours elastosis was also examined in relation to Ki-67 and epidermal growth factor receptor (EGFR) immunostaining. Sensitivity and specificity of DEL and TEL for predicting the receptor, Ki-67 and EGFR findings were estimated. Sensitivity of DEL and TEL for oestrogen and progesterone receptors is dependent on the degree of tumour differen…
Estimating trematode prevalence in snail hosts using a single-step duplex PCR: how badly does cercarial shedding underestimate infection rates?
2014
Background: Trematode communities often consist of different species exploiting the same host population, with two or more trematodes sometimes co-occuring in the same host. A commonly used diagnostic method to detect larval trematode infections in snails has been based on cercarial shedding, though it is often criticized as inaccurate. In the present study we compare infection prevalences determined by cercarial emission with those determined, for the first time, by molecular methods, allowing us to quantify the underestimation of single and double infections based on cercarial emission. We thus developed a duplex PCR for two host-parasite systems, to specifically differentiate between sin…
Ultrastructural study of primary canine and human pigmentary retinopathy
1985
An electron microscopic study was performed on eyes of Labrador dogs afflicted with progressive retinal atrophy (PRA). There was complete loss of photoreceptors, atrophy of the remaining retina and gliosis in the peripheral part while the central retina showed incomplete loss of photoreceptors and an almost total disappearance of photoreceptor outer segments. Melanin-bearing cells, largely containing melanolysosomes, were found deep inside the retina. This electron microscopic study also incorporated the retina of a middle-aged woman affected by retinopathia pigmentosa (RP). The fine structure of the diseased retina showed a similar pattern of lesions, more pronounced in the periphery of th…
Chromoendoscopy and intravital staining techniques.
2000
Chromoendoscopy and intravital staining techniques are synonymous methods for the endoscopic early detection of malignant changes in the intestinal tract. Endoscopic intravital staining involves the use of absorptive stains (methylene blue and Lugol's solution), contrast stains (indigo carmine) and reactive stains (Congo red). Lugol's iodine solution is used to identify superficial carcinomas in the squamous epithelium of the oesophagus. Methylene blue stains the specialized intestinal epithelium in Barrett's oesophagus and, in addition to this, is helpful in the diagnosis of dysplasia. Intravital staining with indigo carmine contributes to contrasting and accentuating changed mucosal proce…