Multi-modal diffeomorphic demons registration based on point-wise mutual information

In this paper we propose a variational approach for multimodal image registration based on the diffeomorphic demons algorithm. Diffeomorphic demons has proven to be a robust and efficient way for intensity-based image registration. However, the main drawback is that it cannot deal with multiple modalities. We propose to replace the standard demons similarity metric (image intensity differences) by point-wise mutual information (PMI) in the energy function. By comparing the accuracy between our PMI based diffeomorphic demons and the B-Spline based free-form deformation approach (FFD) on simulated deformations, we show the proposed algorithm performs significantly better.

Non-rigid Free-Form 2D-3D Registration Using Statistical Deformation Model

This paper presents a non-rigid free-from 2D-3D registration approach using statistical deformation model (SDM). In our approach the SDM is first constructed from a set of training data using a non-rigid registration algorithm based on b-spline free-form deformation to encode a priori information about the underlying anatomy. A novel intensity-based non-rigid 2D-3D registration algorithm is then presented to iteratively fit the 3D b-spline-based SDM to the 2D X-ray images of an unseen subject, which requires a computationally expensive inversion of the instantiated deformation in each iteration. In this paper, we propose to solve this challenge with a fast B-spline pseudo-inversion algorithm that is implemented on graphics processing unit (GPU). Experiments conducted on C-arm and X-ray images of cadaveric femurs demonstrate the efficacy of the present approach.

Levoatrial cardinal vein in mitral atresia and closed foramen ovale: prenatal diagnosis and perinatal management

A levoatrial cardinal vein is a rare cardiovascular anomaly that may be present in malformed hearts with severe left heart obstruction and restrictive interatrial communication. We report the prenatal diagnosis at 23 weeks of a fetus with mitral atresia, double-outlet right ventricle, premature closure of the foramen ovale and a levoatrial cardinal vein draining into the innominate vein. In a prior examination performed elsewhere the levoatrial cardinal vein had been interpreted as an aortic arch perfused retrogradely, and hypoplastic left heart syndrome with aortic atresia had been diagnosed. Prenatal management, induction at 38 weeks and postnatal examinations and treatment are reported. To the best of our knowledge, this is the first reported prenatal diagnosis of this embryological vessel, presenting a potential pitfall for prenatal echocardiography.