Raster-scan optoacoustic angiography at 532 nm wavelength with 50 μm lateral resolution at 2 mm diagnostic depth was used for quantitative characterization of neoangiogenesis in colon cancer models. Two tumor models of human colon adenocarcinoma (HT-29) and murine colon carcinoma (CT26) different in their histology and vascularization were compared. Tumors of both origins showed an inhomogeneous distribution of areas with high and low vascularization. Rapidly growing CT26 tumor demonstrated a higher rate of vessel growth from the periphery to the center. Peculiarities of the vascularity of tumor models revealed by optoacoustic imaging were confirmed by fluorescent microscopy with FITC-dextran and morphological analysis. The obtained results may be important for the investigation of tumor development and for improvement of colon cancer treatment strategies.
The paper analyzes the experience of catheter treatment of various types of supraventricular arrhythmias in patients with Ebstein’s abnormality (EA) – 19 consecutive cases of the elimination of additional atrioventricular connections (AAVC) and 5 cases of atrial macro-reentry. The elimination of AAVC, just like atrial macroreentry, was preceded by a stage of electrophysiological diagnosis. In a series of observations in 19 patients with EA, 25 AAVC were detected. The article reflects the main electrophysiological differences between “wide” AAVC from multiple ones. In the first procedure, the conduction in all AAVC was eliminated in 16 (84.2%) of 19 patients. 6 of 25 AAVC were qualified by us as “wide”; to eliminate them, a larger number of applications was required – 6 ± 2 (in typical cases – 3 ± 1). In 2 of 3 patients with an unsatisfactory result of the first procedure, AAVC were eliminated during the second procedure. In the long-term period(5.6 ± 3.6 years), recurrences of propagation through AAVC occurred in 2 (10.5%) of 19 patients. All AAVC were permanently eliminated during second procedure. In the group of patients with atrial tachycardia, 3 had a graph characteristic of a typical isthmus-dependent atrial flutter. In one patient with atypical graphics, macro-reentry with excitation circulation around the scar on the anterolateral wall of the right atrium was found. In 3 of 4 patients with isthmus-dependent atrial flutter after radiofrequency exposure, the sinus rhythm was restored and a block of passage through the cavotricuspid isthmus was created. In one case there were changes in the cycle of tachycardia and the morphology of wave P, applying applications between the scar and the tricuspid valve ring led to the creation of a block of passage through this area and to the cessation of arrhythmia. In a patient who initially had reentry with a circulation of excitement around the postoperative scar, arrhythmia was eliminated in a similar way (an additional block was created through the cavotricuspid isthmus). In the observation period of 5.2 ± 2.5 years, there were no recurrences of arrhythmia.
Our work was devoted to the experimental comparison of two ultra-wideband detectors based on PVDF piezofilms of different thickness demonstrating different quality of optoacoustic imaging of vessels in tumor and normal tissues.
We propose a GPU-accelerated implementation of frequency-domain synthetic aperture focusing technique (SAFT) employing truncated regularized inverse k-space interpolation. Our implementation achieves sub-1s reconstruction time for data sizes of up to 100 M voxels, providing more than a tenfold decrease in reconstruction time as compared to CPU-based SAFT. We provide an empirical model that can be used to predict the execution time of quasi-3D reconstruction for any data size given the specifications of the computing system.
The aim of the study is to characterize a new information and telecommunication technology -event-related of the heart rate telemetry -for remote monitoring of cognitive functions and stress conditions in the context of everyday activity.Results.A new technology of event-related telemetry of the heart rate has been developed and characterized in terms of the cognitive function monitoring.The optimal architecture of this system provides for continuous monitoring of the patient's functional state in the context of sensorimotor activity while controlling the features of information images in the virtual computer environment.Errors in this control function are considered to objectively reflect the primary cognitive functions and sensorimotor coordination.The possibility of using such multilevel psychophysiological monitoring throughout the everyday life activity is discussed. Conclusion.A novel automated expert system -event-related telemetry -has been developed; this includes hardware, algorithmic and software Internet resources for detecting the early signs of stress and cognitive function impairment in the real time mode, without restricting person's mobility and without attracting his/her attention to the measurement process.
The method of cost-effective upgrade from an acoustic resolution photoacoustic microscope to a triple-modality imaging system is presented. The newly-developed experimental setup is based on a diode-pumped laser coupled to a fiber bundle with a spherically focused polyvinylidene fluoride detector integrated into the center of a ring-shaped optical illuminator. Each laser pulse illuminating the sample performs two functions. While the photons absorbed by the sample provide a measurable optoacoustic (OA) signal, the photons absorbed by the detector provide the measurable diffuse reflectance (DR) from the sample and the probing ultrasonic (US) pulse. At a 3 mm imaging depth the axial resolution of the OA/US modalities is 38µm/26μm, while the lateral resolution of the DR/OA/US modalities is 3.5mm/50μm/35μm. At BIOMED conference we will present the imaging capabilities of the developed DR/OA/US system using the results on phantom and in vivo experiments. While the DR modality complements the OA one by imaging both the heterogeneities of the optical absorption and the scattering, the US modality generates higher-resolution images of the mechanical contrast providing anatomical guidance for in vivo OA studies.
