Characterization of the Physiological Displacement of the Aortic Arch Using Non-Rigid Registration and MR Imaging.

OBJECTIVES: The aim of this work was to study physiological aortic arch three-dimensional displacement using non-rigid registration methods and magnetic resonance imaging (MRI). MATERIALS AND METHODS: Ten healthy volunteers underwent thoracic MRI. Prospective cardiac gating was performed with a 3D turbo field echo sequence to obtain end-systolic and end-diastolic MR images. The rigid and elastic behavior between these two cardiac phases was detected and compared using either an affine or an elastic registration method. To assess reproducibility, a second MRI acquisition was performed 14 days later. RESULTS: Affine registration between the end-systolic and end-diastolic MR images showed significant global translations of the aortic arch and the supra-aortic vessels in the x, y, and z directions (2.02 ± 1.6, -0.71 ± 1.1, and -1.21 ± 1.4 mm, respectively). Corresponding elastic registration indicated significant local displacement with a vector magnitude of 5.1 ± 0.89 mm for the brachiocephalic artery (BCA), of 4.26 ± 0.83 mm for the left common carotid artery (LCCA), and of 4.8 ± 0.86 mm for the left subclavian artery (LSCA). There was a difference in displacement between the supra-aortic trunks of the order of 2 mm. Vector displacement was not statistically different between the repeated acquisitions. CONCLUSIONS: The present results showed important deformations in the ostia of supra-aortic vessels during the cardiac cycle. It seems that aortic arch motions should be taken into account when designing and manufacturing fenestrated endografts. The elastic registration method provides more precise results, but is more complex and time-consuming than other methods.

[Echographic diagnosis of systolic murmur among 280 young French militaries. Implications for the expertise in military medicine]. / Diagnostic échographique d'un souffle cardiaque systolique au sein d'une population de 280 jeunes militaires français. Implications en médecine d'expertise militaire.

UNLABELLED: Clinically discovering a systolic murmur is frequent among the young military population. When this murmur does not sound benign, a transthoracic echocardiography (TTE) is made to detect any cardiopathy, which could cause sudden cardiac death. The aim of this study was to evaluate the interest of systematic TTE in the assessment of any cardiac systolic murmur (CSM) among militaries. METHODS: We ran a retrospective monocentric study in the "Clermont-Tonnerre" military hospital in Brest. We included all patients sent for TEE, aged 15 to 30 years old, from the 1st January 2010 until the 31st July 2013. RESULTS: Two hundred and eighty TTES assessing CSM were performed. We found 28/280 (10%) echocardiographic abnormalities: 13 were bicuspid aortic valves (4.6%), 6 were ventricular septal defects (2.15%), 3 were atrial septal defects (1.07%), 4 were mild mitral regurgitations (1.43%), one mild pulmonary stenosis (0.35%) and one aortic stenosis (0.35%). No hypertrophic cardiomyopathy was found. Concerning military expertise, 11 (3.92%) patients among these 28 with abnormal TEE were considered unfit for work or "fit for work with limitations". CONCLUSION: Assessing a cardiac systolic murmur with TEE lead to the diagnosis of a cardiomyopathy in 10% of the case. This study enhances the importance of systematic TEE when a CSM is detected in the young military, in order to determine if those soldiers can still fulfill their military duty.

Normalized left ventricular workload using phase-contrast magnetic resonance imaging in patients with aortic stenosis.

Aortic stenosis (AS) severity contributes to the left ventricle (LV) deterioration due to the aortic valve narrowing and the alteration of systemic hemodynamic load. This load increment may also increase the LV stroke work (SW) which represent the required energy to deliver the blood at ejection. In this study, SW was derived from in-vivo cardiovascular magnetic resonance (CMR) velocity measurements (n=57) using a lumped-parametric model. Furthermore, normalized SW (N-SW) was evaluated as AS severity parameter. SW differentiated from normal flow (>35 mL/m(2)) and low flow (<35 mL/m(2)) states (p<0.05). N-SW showed a good association with valve effective orifice area (EOA, r=-0.5, p<0.001) and valvulo-arterial impedance (ZVA, r=0.65, p<0.001). A severity threshold for N-SW (1.5 cJ/mL) was found using an EOA=1 cm(2) as AS severity marker. CMR-derived SW and N-SW may be useful to the assessment and grading of AS patients.

[Epidemiology and risk factors of venous thromboembolism]. / Épidémiologie et facteurs de risque de la maladie veineuse thromboembolique.

INTRODUCTION: Venous thromboembolism (VTE) is a common disease. The incidence rises markedly with increasing age; over the age of 75, the annual incidence reaches 1 per 100. BACKGROUND: Besides major risk factors (surgery, trauma and acute medical illness), four risk factors have to be taken into account in the management of VTE: increasing age, cancer, previous history of VTE and pregnancy. To date, with the exception of the antiphospholipid syndrome and antithrombin deficiency, "thrombophilias" do not appear to change the management of VTE. VIEWPOINTS: "Thrombophilias" are useful tools for understanding the pathophysiology of VTE. Therefore, further studies are needed to identify new biological anomalies and their impact on the risk of VTE. Recently, links between VTE and atherosclerosis have been demonstrated, leading to new concept of pan-vascular disease and prevention. CONCLUSIONS: VTE is a major public health problem. The knowledge of VTE risk factors is of major importance in identifying high-risk patients and in reducing the incidence and mortality of VTE.