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In this paper, we demonstrate that image processing algorithms (IPAs) can perform a new visual task, namely, selecting and locating regions-of-interest (ROIs). This task has been defined on the basis of a theory of human vision: the scanpath theory. Further, using the measures S[sub p] and S[sub s], the similarity of location and ordering, respectively, developed over the years in studying human perception and the active looking role of eye movements, we could quantify the efficient and efficacious manner by which IPAs can imitate human vision in locating ROIs. The methodology in this paper is applied to the Mars Rover exploration. [ABSTRACT FROM AUTHOR]

BACKGROUND: Before trans-catheter aortic valve implantation (TAVI), assessment of cardiac function and accurate measurement of the aortic root are key to determine the correct size and type of the prosthesis. The aim of this study was to compare cardiovascular magnetic resonance (CMR) and trans-thoracic echocardiography (TTE) for the assessment of aortic valve measurements and left ventricular function in high-risk elderly patients submitted to TAVI. METHODS: Consecutive patients with severe aortic stenosis and contraindications for surgical aortic valve replacement were screened from April 2009 to January 2011 and imaged with TTE and CMR. RESULTS: Patients who underwent both TTE and CMR (n = 49) had a mean age of 80.8+/-4.8 years and a mean logistic EuroSCORE of 14.9+/-9.3 %. There was a good correlation between TTE and CMR in terms of annulus size (R2=0.48, p<0.001), left ventricular outflow tract (LVOT) diameter (R2 =0.62, p<0.001) and left ventricular ejection fraction (LVEF) (R2=0.47, p<0.001) and a moderate correlation in terms of aortic valve area (AVA) (R2=0.24, p<0.001). CMR generally tended to report larger values than TTE for all measurements. The Bland-Altman test indicated that the 95% limits of agreement between TTE and CMR ranged from -5.6 mm to +1.0 mm for annulus size, from -0.45 mm to +0.25 mm for LVOT, from -0.45 mm2 to +0.25 mm2 for AVA and from -29.2% to 13.2% for LVEF. CONCLUSIONS: In elderly patients candidates to TAVI, CMR represents a viable complement to transthoracic echocardiography. [ABSTRACT FROM AUTHOR]