Optimization of the method for assessment of brain perfusion in humans using contrast-enhanced reflectometry: multidistance time-resolved measurements.

The aim of the study was to determine optimal measurement conditions for assessment of brain perfusion with the use of optical contrast agent and time-resolved diffuse reflectometry in the near-infrared wavelength range. The source-detector separation at which the distribution of time of flights (DTOF) of photons provided useful information on the inflow of the contrast agent to the intracerebral brain tissue compartments was determined. Series of Monte Carlo simulations was performed in which the inflow and washout of the dye in extra- and intracerebral tissue compartments was modeled and the DTOFs were obtained at different source-detector separations. Furthermore, tests on diffuse phantoms were carried out using a time-resolved setup allowing the measurement of DTOFs at 16 source-detector separations. Finally, the setup was applied in experiments carried out on the heads of adult volunteers during intravenous injection of indocyanine green. Analysis of statistical moments of the measured DTOFs showed that the source-detector separation of 6 cm is recommended for monitoring of inflow of optical contrast to the intracerebral brain tissue compartments with the use of continuous wave reflectometry, whereas the separation of 4 cm is enough when the higher-order moments of DTOFs are available.

[Utility of point-of-care ultrasound in lung disease diagnosis]. / Przydatnosc point-of-care USG w diagnostyce chorób pluc.

A new method in the diagnostics of respiratory failure is lung ultrasound (LUS). The test assesses the pleural line and its related artefacts caused by the changing content of extravascular lung water which conditions the degree of lung aeration. Assessment of the movement of the pleural line and the related artefacts (A lines and B lines) enables diagnosis of respiratory failure and treatment monitoring. The advantage of LUS is the possibility of assessing lung function in real time, and the possibility of obtaining information about aeration of the examined part of lung parenchyma. In comparison to other imaging methods, ultrasound is characterized by a considerable specificity and sensitivity in diagnostics and differentiation of numerous diseases, such as pneumothorax, pneumonia, ARDS, and pulmonary edema.