Papers by Chantale Lapierre
American Journal of Roentgenology, 2012
RadioGraphics, 2003
Magnetic resonance (MR) imaging was used to evaluate the position of a large atrial septal occlud... more Magnetic resonance (MR) imaging was used to evaluate the position of a large atrial septal occluder (ASO) with regard to adjacent cardiac valves and veins and to assess any negative effects of the ASO on these vital structures. A total of 26 pediatric patients (mean age, 4.5 years; mean interval after implantation, 18.8 months) were evaluated with cardiac MR imaging. The position of the ASO was best depicted with two-dimensional cine fast low-angle shot imaging. The authors observed impingement of the ASO on the right superior pulmonary vein in 14 patients, on the right inferior pulmonary vein in three patients, on the right superior vena cava in 13 patients, and on the right inferior vena cava in nine patients. In two patients, protrusion of the ASO into the right inferior vena cava was associated with coronary sinus prominence. The ASO was in contact with the mitral valve in 10 patients. Deformation of the aortic valve and root was evident at the onset of the R wave in 19 patients and persisted throughout the cardiac cycle in five of these patients. Cardiac MR imaging reliably depicted the position of the ASO with regard to vital structures. Despite the protrusion of the ASO, no significant effects on venous structures or cardiac valves were observed.
Medical Imaging 2012: Image-Guided Procedures, Robotic Interventions, and Modeling, 2012
Percutaneous cardiac interventions rely mainly on the experience of the cardiologist to safely na... more Percutaneous cardiac interventions rely mainly on the experience of the cardiologist to safely navigate inside soft tissues vessels under X-ray angiography guidance. Additional navigation guidance tool might contribute to improve reliability and safety of percutaneous procedures. This study focus on major aorta-pulmonary collateral arteries (MAPCAs) which are pediatric structures. We present a fully automatic intensity-based 3D/2D registration method that accurately maps pre-operatively acquired 3D tomographic vascular data of a newborn patient over intra-operatively acquired angiograms. The tomographic dataset 3D pose is evaluated by comparing the angiograms with simulated X-ray projections, computed from the pre-operative dataset with a proposed splatting-based projection technique. The rigid 3D pose is updated via a transformation matrix usually defined in respect of the C-Arm acquisition system reference frame, but it can also be defined in respect of the projection plane local reference frame. The optimization of the transformation is driven by two algorithms. First the hill climbing local search and secondly a proposed variant, the dense hill climbing. The latter makes the search space denser by considering the combinations of the registration parameters instead of neighboring solutions only. Although this study focused on the registration of pediatric structures, the same procedure could be applied for any cardiovascular structures involving CT-scan and X-ray angiography. Our preliminary results are promising that an accurate (3D TRE 0.265 ± 0.647mm) and robust (99% success rate) bi-planes registration of the aorta and MAPCAs from a initial displacement up to 20mm and 20 • can be obtained within a reasonable amount of time (13.7 seconds).
Journal de Radiologie, 2009
Journal de Radiologie Diagnostique et Interventionnelle
Les techniques chirurgicales destinées à réparer la tétralogie de Fallot ainsi que les techniques... more Les techniques chirurgicales destinées à réparer la tétralogie de Fallot ainsi que les techniques d'imagerie en coupes se sont améliorées au cours des dernières années. Aujourd'hui, la survie après une réparation complète est supérieure à 90 % à 40 ans. Un suivi est nécessaire et l'évaluation par imagerie doit se faire sur la base des techniques chirurgicales utilisées. Dans cet article, nous examinerons les procédures chirurgicales les plus fréquemment utilisées pour une réparation complète, les complications anatomiques et hémodynamiques associées, de même que le rôle de l'imagerie cardiaque, principalement de l'IRM. © 2016Éditions françaises de radiologie. Publié par Elsevier Masson SAS. Tous droits réservés. La tétralogie de Fallot (ToF) est la cardiopathie congénitale cyanogène la plus fréquente, avec une incidence d'environ 0,5/1000 naissances vivantes (5 à 7 % des cardiopathies congénitales). Sans intervention chirurgicale, la plupart des patients décèdent au cours de l'enfance, avec un taux de survie de 66 % à un an, 11 % à 20 ans et 3 % à 40 ans. Depuis l'apparition de la réparation chirurgicale complète en 1955, le pronostic à long terme de ces patients s'est amélioré, mais l'espérance de vie reste réduite par rapport à la population normale appariée selon l'âge [1]. La réparation complète effectuée au cours des premiers mois de vie est actuellement réalisable avec un faible taux de mortalité (< 2 %) [2,3]. Néanmoins, les complications, les lésions résiduelles et les séquelles sont fréquentes.
Pediatric …, 2010
Kawasaki disease (KD) related coronary artery (CA) aneurysms may lead to significant and potentia... more Kawasaki disease (KD) related coronary artery (CA) aneurysms may lead to significant and potentially insidious progressive stenosis. It is also well recognized that CA scarring leads to heavy calcification in KD. We intended to correlate the angiographic anomalies associated with coronary calcifications in KD and to evaluate the chronology and the detection rate of KD-related CA calcification on plain chest X-ray. Between 1992 and 2006, 65 CA angiograms were performed in 50 KD patients. Chest fluoroscopies and angiograms were retrospectively reviewed. When angiograms were abnormal, chest X-rays were reviewed by two radiologists blinded to the results of angiograms. CA lesions were identified in 18/50 (36%) patients, including isolated CA aneurysms in 10. All 8 patients who had CA aneurysms associated with stenosis and/or occlusion had CA calcification identifiable on chest X-ray. All significant stenotic lesions were concomitant with calcification. Plain chest X-ray, a simple inexpensive low dose mean, easily identifies KD patients at risk for serious CA stenosis when specific search for CA calcification is pursued. When detected, a closer tracking of coronary artery patency is warranted via other imaging techniques, usually expensive, invasive, requiring sedation in children or exposing to high radiation.
Pediatric Cardiology, 2010
Therapeutic strategies for isolated unilateral absence of a proximal pulmonary artery remain uncl... more Therapeutic strategies for isolated unilateral absence of a proximal pulmonary artery remain unclear. The natural history of the disease, or thrombosis of primary surgical anastomosis, leads to exclusion of the affected lung with increased risk of intrapulmonary bleeding, impaired quality of life, and shortened life expectancy. We herein describe our two-stage approach in a small series of patients starting with interventional catheterization followed by surgical anastomosis. Other medical interventions, such as anticoagulation and pulmonary vasodilatation, are key factors to successfully restore pulmonary circulation in this rare defect.
Pediatric Cardiology, 2010
Therapeutic strategies for isolated unilateral absence of a proximal pulmonary artery remain uncl... more Therapeutic strategies for isolated unilateral absence of a proximal pulmonary artery remain unclear. The natural history of the disease, or thrombosis of primary surgical anastomosis, leads to exclusion of the affected lung with increased risk of intrapulmonary bleeding, impaired quality of life, and shortened life expectancy. We herein describe our two-stage approach in a small series of patients starting with interventional catheterization followed by surgical anastomosis. Other medical interventions, such as anticoagulation and pulmonary vasodilatation, are key factors to successfully restore pulmonary circulation in this rare defect.
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Papers by Chantale Lapierre