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In this paper, we propose a new framework to perform nonrigid surface registration. It is based on various extensions of an iterative algorithm recently presented by several researchers (Besl and McKay, 1992; Champleboux et al., 1992; Chen and Medioni, 1992; Menq and Lai, 1992; Zhang, 1994) to rigidly register surfaces represented by a set of 3D points,(More)
Some medical interventions require knowing the correspondence between an MRI/CT image and the actual position of the patient. Examples are in neurosurgery or radiotherapy, but also in video surgery (laparoscopy). Recently, computer vision techniques have been proposed to find this correspondence without any artificial markers. Following the pioneering work(More)
Single photon emission computed tomography (SPECT) imaging with 201Tl or 99mTc agent is used to assess the location or the extent of myocardial infarction or ischemia. A method is proposed to decrease the effect of operator variability in the visual or quantitative interpretation of scintigraphic myocardial perfusion studies. To effect this, the patient's(More)
projection) which maps a 3D object onto a 2D image of this object, the relative positions of the 3D object and the Some medical interventions require knowing the correspondence between an MRI/CT image and the actual position of 2D sensor being unknown. the patient. Examples occur in neurosurgery and radiotherapy, This problem can be solved with artificial(More)
We present in this paper a new registration and gain correction algorithm for 3D medical images. It is intensity based. The basic idea is to represent images by 4D points x j ; y j ; z j ; i j and to deene a global energy function based on this representation. For minimisa-tion, we propose a technique which does not require computing the derivatives of this(More)
Cardiologists assume that analysis of the motion of the heart (especially the left ventricle) can provide useful information about the health of the myocardium. A 4-D polar transformation is defined to describe the left-ventricle (LV) motion and a method is presented to estimate it from sequences of 3-D images. The transformation is defined in 3-D(More)
Early detection of deterioration in hospital patients followed by intervention and stabilization can prevent adverse events such as a cardiac arrest, unscheduled admission to ICU, or death. Patients at step-down units of hospitals tend to have their vital signs checked by nursing staff at 4-hourly intervals. If an abnormality develops in the period between(More)