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The computational analysis suggested a protective effect, rather than steal phenomenon, of the apicoaortic conduit towards the cerebral perfusion, even in cases of mixed aortic valve disease.

Renal ultrasound was evaluated as a screening procedure for urological conditions (hydronephrosis or space-occupying lesions) in 175 patients (316 kidneys) with renal failure. The final diagnosis of renal disease was based on excretory urography, ascending or translumbar pyelography, open surgical findings, clinical and laboratory test results or renal biopsies. Ultrasonic images suggestive of renal disease requiring surgery were obtained in 83 kidneys and subsequently confirmed in 67. There were 16 falsely positive and 2 falsely negative results. Assuming a 22 per cent prevalence of renal disease requiring surgery in the azotemic population, Bayes' theorem predicts that an abnormal ultrasonic test will increase the probability of surgery in a patient with renal failure from 0.22 to 0.81, while a negative test will reduce the probability from 0.22 to 0.013. Renal ultrasound is a highly effective method to screen for patients with renal failure who require contrast studies. With this means the risks and cost of contrast investigations can be reduced markedly.

Cardiovascular diseases are considered to be the main cause of death in developed countries. Due to limitations resulting from in-vivo measurements of velocity, the analysis and evaluation of hemodynamic parameters by means of computational simulations have become the only efficient solution, especially in cases of pathological ventricle or of assisted conditions. A Left Ventricular Assist Device (LVAD) has been used to provide hemodynamic support to patients with critical cardiac failure. The approach used in this work is to develop a Computational Fluid Dynamics (CFD) model of the aorta, including a mechanical support similar to the LVAD (Jarvik 2000 Heart Inc, New York, NY) in order to assess its effects on local haemodynamics. Its purpose is to analyse the hemodynamic effects of a continuous flow LVAD, evaluated in three different working conditions, taking into account the outflow-graft anastomosis in two different locations: thoracic and ascending aorta.

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