Digital diaphanoscopy of the maxillary sinuses: A revival of optical diagnosis for rhinosinusitis.

PURPOSE: The non-invasive diagnosis of acute rhinosinusitis (ARS) remains an unresolved problem of modern otolaryngology. Analog diaphanoscopy of reduced transillumination (shading) could be enhanced by a digital image processing of the maxillary sinuses. By this means, the limited ergonomics of this safe and low-cost method can be overcome, and merits renewed the investigation. Here, we compared the diagnostic sensitivity and specificity of digital diaphanoscopy and computed tomography (CT) in detecting shading in the maxillary sinus. MATERIALS AND METHODS: We examined 103 adults using both digital diaphanoscopy of the maxillary sinus and native-phase cranial CT. We developed a scoring system for investigation of shading in the maxillary sinus using diaphanoscopy and compared the sensitivity and specificity with that of CT. Also, we documented a follow-up of acute rhinosinusitis. RESULTS: In diagnosing shading in the maxillary sinus, digital diaphanoscopy had a sensitivity of 86% and a specificity of 88%. Digital diaphanoscopy can be used not only in the screening of ARS but also for documentation of its course. CONCLUSION: This study supports the role of modern digital diaphanoscopy in the diagnosis of shading in the maxillary sinus, especially in patients with ARS when CT imaging is not recommended. The ergonomics of analog diaphanoscopy could be significantly improved for physicians and patients by the implementation of modern hardware and software components. Further development of the technique and the use of several discrete wavelengths will improve this method's sensitivity and specificity.

Synergy Effect of Combined Near and Mid-Infrared Fibre Spectroscopy for Diagnostics of Abdominal Cancer.

Cancers of the abdominal cavity comprise one of the most prevalent forms of cancers, with the highest contribution from colon and rectal cancers (12% of the human population), followed by stomach cancers (4%). Surgery, as the preferred choice of treatment, includes the selection of adequate resection margins to avoid local recurrences due to minimal residual disease. The presence of functionally vital structures can complicate the choice of resection margins. Spectral analysis of tissue samples in combination with chemometric models constitutes a promising approach for more efficient and precise tumour margin identification. Additionally, this technique provides a real-time tumour identification approach not only for intraoperative application but also during endoscopic diagnosis of tumours in hollow organs. The combination of near-infrared and mid-infrared spectroscopy has advantages compared to individual methods for the clinical implementation of this technique as a diagnostic tool.

Synergy of Fluorescence and Near-Infrared Spectroscopy in Detection of Colorectal Cancer.

BACKGROUND: Colorectal cancer is one of the most common malignancies worldwide. There is an urgent need for simple and fast methods to improve tumor detection in the diagnostic and intraoperative setting to avoid complications and provide objective information in distinguishing malignant and benign colorectal tissue. Optical spectroscopy methods have recently shown a great potential for this discrimination in different organs. MATERIALS AND METHODS: In this pilot study, fluorescence emission spectra (excitation: 473 nm) and diffuse reflectance spectra (DRS) of normal and tumor tissues from resected colorectal cancer specimen were measured using fiber optical probes in an ex vivo setting, and the data were subjected to multivariate analysis. RESULTS: Substantial spectral differences were found in the fluorescence and DRS spectra of colorectal cancer tissue in comparison to benign tissue. The diagnostic potential of a multimode optical system combining both spectroscopic methods was investigated by mathematical combination. Compared with the individual techniques, a higher sensitivity of the joint DRS-fluorescence optical system in the discrimination between malignant and benign colorectal tissue could be observed. CONCLUSIONS: In the pilot study presented herein, a quick and reliable method to differentiate malignant and benign colorectal tissue ex vivo with different spectroscopic techniques using spectral fiber probes could be established. Joint fluorescence and near-infrared spectroscopy had a higher sensitivity in tissue discrimination and showed to be a promising combination of two spectroscopic methods. Further studies using the synergic effect of fluorescence and DRS spectroscopy are needed to transfer these findings into the in vivo situation.

Development and Testing of an LED-Based Near-Infrared Sensor for Human Kidney Tumor Diagnostics.

Optical spectroscopy is increasingly used for cancer diagnostics. Tumor detection feasibility in human kidney samples using mid- and near-infrared (NIR) spectroscopy, fluorescence spectroscopy, and Raman spectroscopy has been reported (Artyushenko et al., Spectral fiber sensors for cancer diagnostics in vitro. In Proceedings of the European Conference on Biomedical Optics, Munich, Germany, 21-25 June 2015). In the present work, a simplification of the NIR spectroscopic analysis for cancer diagnostics was studied. The conventional high-resolution NIR spectroscopic method of kidney tumor diagnostics was replaced by a compact optical sensing device constructively represented by a set of four light-emitting diodes (LEDs) at selected wavelengths and one detecting photodiode. Two sensor prototypes were tested using 14 in vitro clinical samples of 7 different patients. Statistical data evaluation using principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) confirmed the general applicability of the LED-based sensing approach to kidney tumor detection. An additional validation of the results was performed by means of sample permutation.

Synergy Effect of Combining Fluorescence and Mid Infrared Fiber Spectroscopy for Kidney Tumor Diagnostics.

Matching pairs of tumor and non-tumor kidney tissue samples of four patients were investigated ex vivo using a combination of two methods, attenuated total reflection mid infrared spectroscopy and fluorescence spectroscopy, through respectively prepared and adjusted fiber probes. In order to increase the data information content, the measurements on tissue samples in both methods were performed in the same 31 preselected positions. Multivariate data analysis revealed a synergic effect of combining the two methods for the diagnostics of kidney tumor compared to individual techniques.

Microscopical heat stress investigations under application of quantum dots.

Heat stress responses are analyzed in cancer cells by applying different microscopy techniques for targeting various fluorescently labeled or native structures. Thermotreatments are performed at 40, 45, 50, and 56 degrees C, respectively, for 30 min each, while controls were kept at 37 degrees C. Actin cytoskeletons labeled with Alexa Fluor 488-conjugated phalloidin are imaged by wide-field fluorescence microscopy (WFFM). Structural plasma membrane stabilities are labeled with fluorescent quantum dots and analyzed by laser scanning microscopy (LSM). High-resolution atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to study morphological features and surface structures. Fluorescence images reveal F-actin to be a comparatively thermolabile cell component showing distinctive alteration after heat treatment at 40 degrees C. Destabilization of actin cytoskeletons proceed with increasing stress temperatures. Active reorganization of plasma membranes coincidental to heat-induced shrinkage and rounding of cell shapes, and loosening of monolayered tissue are observed after treatment at 45 or 50 degrees C. Active stress response is inhibited by stress at 56 degrees C, because actin cytoskeletons as well as plasma membranes are destroyed, resulting in necrotic cell phenotypes. Comparing data measured with the same microscopic technique and comparing the different datasets with each other reveal that heat stress response in MX1 cells results from the overlap of different heat-induced subcellular defects.

Comparison of Photo Optical Imaging with Musculoskeletal Ultrasound and Clinical Examination in the Assessment of Inflammatory Activity in Proximal Interphalangeal Joints in Rheumatoid Arthritis and Osteoarthritis.

OBJECTIVE: Lightscan is a novel, rapid, low-cost, easily operated and noninvasive imaging technology used to assess inflammatory activity in proximal interphalangeal (PIP) joints. The results are calculated automatically. To our knowledge, this is the first comparative study of photo optical imaging (POI), with clinical examination (CE), disease activity score at 28 joints (DAS28)-erythrocyte sedimentation rate (ESR), and musculoskeletal ultrasonography (US) in healthy subjects and patients with rheumatoid arthritis (RA) or osteoarthritis (OA). METHODS: There were 688 PIP joints of both hands examined in 87 subjects (38 RA, 21 OA, 28 healthy) by Lightscan and compared with CE for clinically swollen and tender joints, DAS28-ESR (only RA), and US. RESULTS: With US as reference, POI had a sensitivity of 74% and a specificity of 93%. In the receiver-operating curve (ROC) analysis, the Lightscan showed a higher sensitivity and specificity [area under the curve (AUC) 0.879] for the distinction of healthy subjects versus patients (OA, RA) than US in greyscale (GSUS; AUC 0.797) and power Doppler (PDUS; AUC 0.67). POI correlated significantly with GSUS (r 0.473, p < 0.01) and PDUS (r 0.486, p < 0.01). The agreement rates between POI and GSUS were up to 79%, between POI and PDUS up to 92%, and between POI and CE up to 66%. POI did not correlate with DAS28-ESR. CONCLUSION: The Lightscan is a new technology offering sensitive imaging detection of inflammatory changes in subjects with RA and OA with PIP arthritis. POI was more sensitive than CE and correlated significantly to GSUS and PDUS, while presenting a higher sensitivity and specificity for the detection of healthy subjects versus patients (RA, OA) based on the ROC analysis.

Diagnosis of rheumatoid arthritis using light: correction of motion artefacts and color visualization of multispectral images.

State-of-the-art image-processing methods offer new possibilities for diagnosing diseases using scattered light. The optical diagnosis of rheumatism is taken as an example to show that the diagnostic sensitivity can be improved using overlapped pseudocolored images of different wavelengths, provided that multispectral images are recorded to compensate for any motion-related artefacts that occur during examination.

Fluorescence imaging of heat-stress induced mitochondrial long-term depolarization in breast cancer cells.

Various thermotherapies are based on the induction of lethal heat in target tissues. Spatial and temporal instabilities of elevated temperatures induced in therapy targets require optimized treatment protocols and reliable temperature control methods during thermotherapies. Heat-stress induced effects on mitochondrial transmembrane potentials were analyzed in breast cancer cells, species MX1, using the potential sensor JC-1 (Molecular Probes, Invitrogen, Germany). Potential dependant labeling of heat-stressed cells was imaged and evaluated by fluorescence microscopy and compared with control cells. JC-1 stains mitochondria in cells with high mitochondrial potentials by forming orange-red fluorescent J-aggregates while in cells with depolarized or damaged mitochondria the sensor dye exists as green fluorescent monomers. In MX1 cells orange-red and green fluorescence intensities were correlated with each other after various heat-stress treatments and states of mitochondrial membrane potentials were deduced from the image data. With increasing stress temperatures the intensity of red fluorescent J-aggregates decreased while the green fluorescence intensity of JC-1 monomers increased. This heat-stress response happened in a nonlinear manner with increasing temperatures resulting in a nonlinear increase of red/green fluorescence ratios. These data indicated that mitochondria in MX1 cells were increasingly depolarized in response to increasing ambient temperatures.

Heat stress induced redistribution of fluorescent quantum dots in breast tumor cells.

The probing of living cells in different colors over extended periods of time can be used to see the complicated processes that take place during carcinogenesis or heat stress, for example. Since most therapeutic laser tissue interactions are based on thermal effects a detailed characterization of thermal tissue damages in the cellular and sub-cellular levels is important. In order to study such microdosimetry laser-induced fluorescences of Quantum dots provide a suitable approach. Streptavidin conjugated Qdot 605 (Quantum Dot Corp., USA) were used in combination with the concanavalin A-biotin labeling system (Molecular Probes, NL) to observe membrane associated thermal lesions. Fluorescent Qdot conjugates are a promising alternative to organic dyes. The extinction coefficient of Qdot 605 streptavidin conjugate is 650,000 M(-1) cm(-1) at 600 nm. Red fluorescent Qdots 605 were selected because autofluorescence of cells in the red spectral range is not relevant. Fluorescence detection was performed with a confocal laser scan microscope LSM410 (Carl Zeiss, Germany). Breast cancer cells were used in the thermal stressing experiments performed at 40 degrees C, 42 degrees C, 45 degrees C, 50 degrees C or 56 degrees C for 30 min, each. In this methodical approach Qdot mediated labeling of heat stressed cells were demonstrated to show alterations of plasma membrane organizations and integrities, respectively.