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Computed tomography as well as magnetic resonance or positron electron tomography is currently the most commonly used medical imaging modalities for the analysis of human body complex structures and organs, where diseases must be recognized and identified. The image reconstruction process used in these tomography techniques is usually based on the Radon transform (RT). In this paper, an algorithm based on Markov chain Monte Carlo methods for reconstruction of 2D-3D structures is introduced, including correction of noise directly from the RT sinograms. The 3D reconstruction is independent by the instrumental technique and can be applied to any RT-based medical imaging technologies. [ABSTRACT FROM AUTHOR]

This paper discusses the problem of fostering lifestyle changes towards healthier habits via tailored user guidance. We present a novel multisensory device, the Wize Mirror, which will be able to detect semeiotic face signs related to cardio-metabolic risk, and encourage users to reduce their risk by improving their lifestyle. Offering a proper user guidance requires solving three main issues: user profiling, definition of a wellness index based on biophysical data, and personalized guidance by means of coaching and supportive messages. For each of these issues, the solutions proposed in the EU FP7 Project SEMEOTICONS are presented, highlighting their advantages with respect to the state-of-the-art. [ABSTRACT FROM AUTHOR]

Introduction: The magnitude of the oxygen-sparing effect induced by the diving response in humans is still under debate. We wished to compare cardiovascular changes during maximal breath-holding (BH) in air and during whole-body immersion at the surface in a group of BH divers. Methods: Twenty-one divers performed a maximal static apnea in air or during whole-body immersion. Doppler-echocardiography, arterial blood pressure and haemoglobin saturation (SaO2) were obtained at the beginning of, and at 1/3, 2/3 and maximal BH time. Results: BH time was on the average 3.6 ± 0.4 min, with no differences between the two conditions. SaO2 significantly decreased during BH in both conditions, but was significantly higher during immersion as compared to the dry (P = 0.04). In both conditions, BH induced a significant linear increase in right ventricular diameter (P < 0.001), left ventricular (LV) volumes (P < 0.001) and LV stroke volume (P < 0.001) but a significant linear decrease in LV ejection fraction (P = 0.033). In both conditions, Doppler diastolic parameters showed changes suggesting a constrictive/restrictive left ventricular filling pattern (i.e., an increase of early diastolic left ventricular filling velocity, P = 0.005, and a decrease in the deceleration time of early diastolic left ventricular filling. P < 0.001). Conclusion: BH induces progressive LV enlargement both in air and whole-body immersion, associated with reduced LV ejection fraction and progressive hindrance to diastolic filling. For a similar apnea duration, SaO2 decreased less during immersed BH, indicating an O2-sparing effect of diving, suggesting that interruption of apnea was not triggered by a threshold critical value of blood O2 desaturation. [ABSTRACT FROM AUTHOR]

In a previous study, we obtained histologic documentation of liver gas embolism in the rat model of rapid decompression. The aim of the study was to assess in the same model occurrence and time course of liver embolism using 2-D ultrasound imaging, and to explore by this means putative liver gas embolism in recreational scuba divers. Following 42 min compression at 7 ATA breathing air and 12 min decompression, eight surviving female rats were anesthetized and the liver imaged by ultrasound at 20 min intervals up to 120 min. A significant enhancement of echo signal was recorded from 60 to 120 min as compared to earlier post-decompression times. Enzymatic markers of liver damage (AST, ALT, and GGT) increased significantly at 24 h upon decompression. Twelve healthy experienced divers were studied basally and at 15-min intervals up to 60 min following a 30-min scuba dive at 30 msw depth. At 30 min upon surfacing echo images showed significant signal enhancement that progressed and reached plateau at 45 and 60 min. Total bilirubin at 24 h increased significantly (p = 0.02) with respect to basal values although within the reference range. In conclusion, 2-D ultrasound liver imaging allowed detection of gas embolism in the rat and defined the time course of gas accumulation. Its application to scuba divers revealed liver gas accumulation in all subjects in the absence of clear-cut evidence of liver damage or of any symptom. The clinical significance of our findings remains to be investigated. [ABSTRACT FROM AUTHOR]