Enriched environment exposure during development positively impacts the structure and function of the visual cortex in mice.

Optimal conditions of development have been of interest for decades, since genetics alone cannot fully explain how an individual matures. In the present study, we used optical brain imaging to investigate whether a relatively simple enrichment can positively influence the development of the visual cortex of mice. The enrichment paradigm was composed of larger cages housing multiple mice that contained several toys, hiding places, nesting material and a spinning wheel that were moved or replaced at regular intervals. We compared C57BL/6N adult mice (> P60) that had been raised either in an enriched environment (EE; n = 16) or a standard (ST; n = 12) environment from 1 week before birth to adulthood, encompassing all cortical developmental stages. Here, we report significant beneficial changes on the structure and function of the visual cortex following environmental enrichment throughout the lifespan. More specifically, retinotopic mapping through intrinsic signal optical imaging revealed that the size of the primary visual cortex was greater in mice reared in an EE compared to controls. In addition, the visual field coverage of EE mice was wider. Finally, the organization of the cortical representation of the visual field (as determined by cortical magnification) versus its eccentricity also differed between the two groups. We did not observe any significant differences between females and males within each group. Taken together, these data demonstrate specific benefits of an EE throughout development on the visual cortex, which suggests adaptation to their environmental realities.

[Comparison of 2D and 3D techniques in the evaluation of global ventricular function on multidetector-row CT]. / Comparaison des méthodes 2D et 3D dans l'évaluation des fonctions ventriculaires globales en scanner multi-détecteurs.

PURPOSE: To compare two methods of post processing cardiac CT data to measure global ventricular function. Materials and methods. Retrospective study where three readers measured the end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) of the right (n=22) and left (n=44) ventricles, using a 2D method (extrapolated volumetric method, EVM) and a 3D method (direct volumetric method, DVM) after cardiac CT with retrospective ECG gating. Inter- and intraobserver agreement were calculated based on the intraclass correlation coefficient (ICC) with 95% confidence interval (CI95%), and results obtained with each method were compared using the student t test for paired samples. RESULTS: Inter- and intraobserver reproducibility were very good for both methods, with ICC ranging between 0.694 and 0.992, without significant difference. For the left ventricle, EDV, ESV and EF were 16653 ml, 8351 ml and 5415% for DVM et de 20361 ml, 11558 ml and 4613% for EVM respectively. Right ventricular values were 15247 ml, 7534 ml, 5013% and 17253 ml, 9940 ml, 439% (p<0,0001). CONCLUSION: The very good inter- and intraobserver reproducibility for both methods validate their use in clinical practice. Volume measurements with DVM are always inferior to volumes with EDM, with inverse relationship for EF measurements.

[MDCT in the lateral decubitus position with Valsalva maneuver in the evaluation of abdominal wall hernias]. / Scanner multicoupe en latérocubitus avec manoeuvre de Valsalva dans l'étude des hernies de la paroi abdominale.

MDCT in the lateral decubitus position during Valsalva is sensitive in the detection of abdominal wall hernias and may increase the hernia size and possibly change its contents.

[A rare tracheal tumour: solitary fibroma]. / Une cause exceptionnelle de tumeur trachéale: la tumeur fibreuse solitaire.

INTRODUCTION: Solitary fibromas are rare anatomo-pathological entities, described initially in the pleural cavity. The mesenchymal origin of these tumours explains their widespread distribution. CASE REPORT: The authors report a case of solitary fibroma of the trachea in a woman of 30 years of age, presenting as acute respiratory distress and preceded by a 2 year history of episodes of dyspnoea diagnosed as unstable asthma. CT and MRI imaging showed evidence of a localised tracheal tumour without mediastinal infiltration. The images and macroscopic appearances were non-specific. Bronchoscopic resection of the tumour gave immediate relief of the symptoms. Histology, which was positive for anti-CD34 antibodies and negative for epithelial, muscular and neurological markers, led to a diagnosis of solitary fibroma with no evidence of malignancy. CONCLUSION: To our knowledge, this observation is the first description of a primary solitary fibroma localised to the trachea. The clinical and radiological features are no different from those of other tracheal tumours. After excision, the prognosis is good but long-term follow-up is necessary on account of the risk of local recurrence or metastasis.

[Pulmonary artery sarcoma during postpartum: CT findings]. / Sarcome de l'artère pulmonaire dans le post-partum: aspects scanographiques.

We report the case of a 28 year-old female, who gave birth seven weeks previously, presenting with a pulmonary artery leiomyosarcoma discovered on a thoracic CT performed for clinical suspicion of pulmonary embolism. This case presents two major points of interest: on the first hand, it is a particular context (young post-partum patient), with classic symptoms of routine pulmonary embolism. On the other hand, the exam clearly demonstrates tumor enhancement, which is characteristic but rarely described.

[Contribution of EKG-gated multislice CT in the diagnosis of arrhythmogenic right ventricle dysplasia: report of two selected cases]. / Apport du scanner volumique avec synchronisation ECG dans le diagnostic de cardiomyopathie arythmogène du ventricule droit: à propos de deux cas choisis.

Arrhythmogenic cardiomyopathy of the right ventricle is characterized by replacement of right myocardial cells by fibro-fatty tissue and arrhythmias. The authors present two cases where EKG gated multislice CT was valuable. In one case, comprehensive evaluation of extensive ventricular dysplasia complicated by intraventricular thrombus was achieved whereas accurate evaluation of the ventricular wall process was possible in another case.

[Dynamic evaluation of lower limb arteries using the ECTRICKS MRI technique]. / La perspective d'une étude dynamique des artères des membres inférieurs en IRM grâce à la séquence ECTRICKS.

PURPOSE: This article presents a new MR angiography technique, Elliptic Centric Time Resolved Imaging on Contrast KineticS (ECTRICKS), which allows dynamic evaluation of the lower limb arteries opacification when venous return prevents adequate diagnostic evaluation of calf arteries. PATIENTS AND METHODS: Comparative examinations could be compared. Additional arteries in 59 patients using a standard MRA technique and the ECTRICKS technique. RESULTS: A total of 33 examinations could be compared. Additional arteries could be evaluated in 10% of our patient population using the ECTRICKS technique, and in 20% for our diabetic population. Arterial evaluation was better with the ECTRICKS technique in patients with diabetes and venous insufficiency. CONCLUSION: ECTRICKS is a good complementary sequence for evaluation the calf arteries in patients with diabetes or early venous return.

[Imaging of complications of Meckel diverticulum]. / Imagerie des complications du diverticule de Meckel.

Meckel's diverticulum is a persistent embryonic remnant occurring in 2% of the general population. As an "ileal appendix", it is usually clinically silent and only discovered at the time of complications: inflammation, hemorrhage, obstruction, tumor. The preoperative diagnosis is rarely made because of the non specific nature of the symptomatology and only about 10% of complicated cases are diagnosed at imaging. Complications from Meckel's diverticulum should always be considered in patients presenting with an acute abdomen, especially in young adults.

[Secondary diseases of the peritoneum]. / Le péritoine << témoin >> de la pathologie abdomino-pelvienne.

Most inflammatory, infectious or tumoral diseases of the bowel and abdominal organs may secondarily involve the peritoneum which acts as a mirror of the diseases. Multidetector CT allows breathhold acquisitions through the abdomen and pelvis providing high spatial and contrast resolution imaging at all phases of contrast distribution as well as MPR and 3D capabilities.