Tracking chessboard corners using projective transformation for augmented reality

Augmented reality has been a topic of intense research for several years for many applications. It consists of inserting a virtual object into a real scene. The virtual object must be accurately positioned in a desired place. Some measurements (calibration) are thus required and a set of correspondences between points on the calibration target and the camera images must be found. In this paper, we present a tracking technique based on both detection of Chessboard corners and a least squares method; the objective is to estimate the perspective transformation matrix for the current view of the camera. This technique does not require any information or computation of the camera parameters; it can used in real time without any initialization and the user can change the camera focal without any fear of losing alignment between real and virtual object

THU0275 SEVERE PREECLAMPSIA RELATED TO ANTIPHOSPHOLIPID SYNDROME: AN EUROPEAN STUDY OF 40 WOMEN

Background:One of the 3 features of obstetrical antiphospholipid syndrome (APS) is severe preeclampsia (PE). Its time of occurrence, the associated risk of thromboses and systemic lupus erythematosus (SLE) have not been reported yet.Objectives:We analyzed severe PE in a series of women with APS.Methods:We retrospectively collected data of female patients from 5 French internal medicine and 1 Italian rheumatology units. Inclusion criteria were: a severe PE/eclampsia(1), that occurred before 34 weeks of gestation (WG) in patients who met the APS classification criteria(2).Results:40 patients were enrolled (Table 1). Because of known APS/positive aPL/previous obstetrical complications, 23(57.5%) patients were treated during the index PE: 4 with low dose aspirin (LDA), 4 with low molecular weight heparin (LMWH), and 15 with a combination of both. 7 patients were also treated with hydroxychloroquine, 8 with corticosteroids and 3 with immunosuppressants. 17(42.5%) patients received no treatment. 24(60%) live births were observed. During a follow-up period of 3 years, 26(65%) patients had at least 1 new pregnancy, with a total of 38 pregnancies which resulted in 33(86.8%) live births. 57.5% pregnancies who resulted in live births occurred without any maternal or fetal complications. All 26 patients who had at least 1 pregnancy after index PE were treated with LDA; LMWH was given at prophylactic and therapeutic dosage in 13(50%) patients, respectively. No patient experienced 3 consecutive miscarriages.Table 1.40 APS patients with severe PEOverall features (n, %)Patients40 (100)Age at PE, (median, IQR)30.5 (27-33)PE term, WG (median, IQR)25.5 (23-29) Live births24 (60) Birth term, WG (median, IQR)25.5 (23.7-30.3) Associated SLE12 (30)Maternal complications (n, %)25 (62.5) HELLP18 (45) E6 (15) CAPS3 (7.5) Placental abruptions3 (7.5)Fetal complications (n, %)31 (77.5) IUGR18 (45) IUFD11 (2.5) Preterm delivery22 (55)Obstetrical history (n, %) Primiparous21 (52.5) Index PE before APS12 (30)Thrombosis (n, %) Thrombosis before PE index14 (35.0) Thrombosis after PE index2 (5.0)Abs at APS diagnosis (n, %) aPL triple positivity21 (52.5) IgG/IgM anti-cardiolipin34 (85.0) IgG/IgM anti-β2GPI25 (62.5) LAC33 (82.5)Legend to Table 1:PE: preeclampsia; APS: antiphospholipid syndrome; IQR: interquartile range; WG: weeks of gestation; SLE: systemic lupus erythematosus; HELLP: Hemolysis, elevated liver enzymes, low platelet; E: eclampsia; CAPS: catastrophic APS; IUGR: intrauterine growth restriction; IUFD: intrauterine fetal death; CHB: congenital atrioventricular block; aPL: antiphospholipid antibodies; LAC: lupus anticoagulant.Conclusion:Among the APS criteria, "3 consecutive miscarriages criterion" was not found. The majority of patients also experienced thrombosis and SLE before the index PE.References:[1]Diagnosis and Management of preeclampsia and eclampsia. International Journal of Gynecology &Obestetrics 2002;77:67-75.[2]Miyakis S, et al. International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS). J Thromb Haemost 2006;4:295e 306.Disclosure of Interests:Maddalena Larosa: None declared, Nathalie Morel: None declared, Meriem BELHOCINE: None declared, Amelia Ruffatti: None declared, Nicolas Martin Silva: None declared, Romain Paul: None declared, Luc Mouthon: None declared, Michel DREYFUS: None declared, Jean-Charles PIETTE: None declared, Odile Souchaud-Debouverie: None declared, Catherine Deneux-Tharaux: None declared, Vassilis Tsatsaris: None declared, Emmanuelle Pannier: None declared, Gaêlle Guettrot Imbert: None declared, Véronique LE GUERN Grant/research support from: UCB for GR2 study (to our institution), Andrea Doria Consultant of: GSK, Pfizer, Abbvie, Novartis, Ely Lilly, Speakers bureau: UCB pharma, GSK, Pfizer, Janssen, Abbvie, Novartis, Ely Lilly, BMS, Nathalie Costedoat-Chalumeau Grant/research support from: UCB to my institutio

Anatomical classification of the shape and topography of the stomach

The aim of the study was to present the classification of anatomical variations of the stomach, based on the radiological and historical data. In years 2006–2010, 2,034 examinations of the upper digestive tract were performed. Normal stomach anatomy or different variations of the organ shape and/or topography without any organic radiologically detectable gastric lesions were revealed in 568 and 821 cases, respectively. Five primary groups were established: abnormal position along longitudinal (I) and horizontal axis (II), as well as abnormal shape (III) and stomach connections (IV) or mixed forms (V). The first group contains abnormalities most commonly observed among examined patients such as stomach rotation and translocation to the chest cavity, including sliding, paraesophageal, mixed-form and upside-down hiatal diaphragmatic hernias, as well as short esophagus, and the other diaphragmatic hernias, that were not found in the evaluated population. The second group includes the stomach cascade. The third and fourth groups comprise developmental variations and organ malformations that were not observed in evaluated patients. The last group (V) encloses mixed forms that connect two or more previous variations

Midbrain-Hindbrain Involvement in Septo-Optic Dysplasia

BACKGROUND AND PURPOSE: Midbrain-hindbrain involvement in septo-optic dysplasia has not been well described, despite reported mutations of genes regulating brain stem patterning. We aimed to describe midbrain-hindbrain involvement in patients with septo-optic dysplasia and to identify possible clinical-neuroimaging correlations. MATERIALS AND METHODS: Using MR imaging, we categorized 38 patients (21 males) based on the presence (group A, 21 patients) or absence (group B, 17 patients) of visible brain stem anomalies. We measured height and anteroposterior diameter of midbrain, pons, and medulla, anteroposterior midbrain/pons diameter (M/P ratio), vermian height, and tegmento-vermian angle, and compared the results with 114 healthy age-matched controls. Furthermore, patients were subdivided based on the type of midline anomalies. The associations between clinical and neuroradiological features were investigated. Post hoc tests were corrected according to Bonferroni adjustment (pB). RESULTS: Patients with brain stem abnormalities had smaller anteroposterior pons diameter than controls (pB CONCLUSION: Midbrain-hindbrain abnormalities are a significant, albeit underrecognized, component of the septo-optic dysplasia spectrum, and are significantly associated with developmental delay in affected patients

Contribution to restoration of degraded images

No abstract availabl