Liposarcoma of the extremities: MR imaging features and their correlation with pathologic data

SummaryObjectiveTo describe the MRI features of liposarcomas of the extremities and correlate them with data from the histologic subtypes.Material and methodsRetrospective study of 20 cases of liposarcoma of the extremities identified on MRI, surgically removed and confirmed at pathology. On MRI examination, T1- and T2-weighted fat-suppressed and non-fat-suppressed images were acquired then gadolinium-enhanced fat-suppressed T1-weighted images were obtained in at least two orthogonal planes.ResultsSixteen female and four male patients aged 12 to 77 years old at presentation, in 16 cases, with a slowly enlarging painless mass (demonstrating no associated local or general inflammatory components), located in the lower extremity (16 cases) and predominantly located in the thigh (13 cases). Pathologic examination revealed three cases of well-differentiated liposarcoma, 12 cases of myxoid liposarcoma one of which with round cells, three cases of pleomorphic liposarcoma, one case of dedifferentiated liposarcoma and one case of mixed-type liposarcoma. MR images mostly showed well-circumscribed tumors (19 cases) . Well-differentiated liposarcomas typically demonstrated a very specific diagnostic appearance as a predominantly adipose mass containing nonlipomatous components seen as thick septa that may show nodularity. Other subtypes of liposarcoma demonstrated a small amount of adipose tissue thus producing a marbled textural pattern on T1-weighted images particularly in myxoid liposarcomas (9 cases), or even nonlipomatous elements in high-grade liposarcomas (in round cell liposarcoma and in two out of three pleomorphic liposarcomas). The myxoid subtype has also a relatively characteristic appearance as a low signal intensity noted on T1-weighted images and a marked high signal intensity on T2. The dedifferentiated liposarcoma has a very specific radiologic appearance as a nonlipomatous component within a predominantly adipose mass, simulating that of well-differentiated liposarcomas.ConclusionMRI of extremity liposarcomas is a highly reliable and sensitive method to characterize liposarcomas. Besides its value in the diagnosis of liposarcoma and locoregional extension control, it allows proper identification of the specific histologic subtypes of liposarcoma.Level of evidenceLevel IV. Rétrospective diagnostic study

Intrauterine pregnancy following low-dose gonadotropin ovulation induction and direct intraperitoneal insemination for severe cervical stenosis

BACKGROUND: We present a case of primary infertility related to extreme cervical stenosis, a subset of cervical factor infertility which accounts for approximately 5% of all clinical infertility referrals. CASE PRESENTATION: A 37 year-old nulligravida was successfully treated with ovulation induction via recombinant follicle stimulating hormone (FSH) and direct intraperitoneal insemination (IPI). Anticipating controlled ovarian hyperstimulation with in vitro fertilization/embryo transfer (IVF), the patient underwent hysteroscopy and cervical recanalization, but safe intrauterine access was not possible due to severe proximal cervical stricture. Hysterosalpingogram established bilateral tubal patency and confirmed an irregular cervical contour. Since the cervical canal could not be traversed, neither standard intrauterine insemination nor transcervical embryo transfer could be offered. Prepared spermatozoa were therefore placed intraperitoneally at both tubal fimbria under real-time transvaginal sonographic guidance using a 17 gage single-lumen IVF needle. Supplementary progesterone was administered as 200 mg/d lozenge (troche) plus 200 mg/d rectal suppository, maintained from the day following IPI to the 8(th )gestational week. A singleton intrauterine pregnancy was achieved after the second ovulation induction attempt. CONCLUSIONS: In this report, we outline the relevance of cervical factor infertility to reproductive medicine practice. Additionally, our andrology evaluation, ovulation induction approach, spermatozoa preparation, and insemination technique in such cases are described

Pituitary Adenylate Cyclase Activating Peptide (1-38) and its analog (Acetyl-[Ala15, Ala20] PACAP 38-polyamide) reverse methacholine airway hyperresponsiveness in rats

O objetivo deste estudo foi investigar funcionalmente e estruturalmente efeito broncodilatador do peptídeo ativador da adenilato ciclase pituitária (PACAP1-38) e da acetil-[Ala15, Ala20]PACAP 38-poliamida, potente análogo do PACAP-38, nos ratos desafiados pelo metacolina (MeCh). Ratos Wistar machos foram aleatoriamente divididos em cinco grupos. Grupos 1 e 2, inalando aerossóis de solução salina ou doses crescentes de MeCh (0,5, 1, 2,12, 4,25, 8,5, 17, 34 e 68 mg/L). Os outros grupos recebendo terbutalina (Terb) (250 µg/rato) (10-6M), PACAP-38 (50 µg/rato) (0.1 mM) ou análogo do PACAP-38 (50 µg/rato) associados a MeCh na dose de 4,25 mg/L. A resistência pulmonar total (RL) foi registrada antes e 2 min após a administração de Mech pelo equipamento pneumomultiteste. A administração MeCh induziu aumento significativo e dose dependente (pThe aim of this study was to investigate both functionally and structurally bronchodilator effects of Pituitary adenylate cyclase activating peptide (PACAP38) and acetyl-[Ala15, Ala20] PACAP38-polyamide, a potent PACAP38 analog, in rats challenged by methacholine (MeCh). Male Wistar rats were divided randomly into five groups. Groups 1 and 2 inhaled respectively aerosols of saline or increasing doses of MeCh (0.5, 1, 2.12, 4.25, 8.5, 17, 34 and 68mg/L). The other groups received terbutaline (Terb) (250 µg/rat) (10-6 M), PACAP38 (50 µg/rat) (0.1 mM) or PACAP38 analog (50 µg/rat) associated to MeCh from the dose of 4.25 mg/L. Total lung resistances (RL) were recorded before and 2 min after MeCh administration by pneumomultitest equipment. MeCh administration induced a significant and a dose-dependent increase (

On the stability of modal methods when dealing with lamellar structures with extreme filling ratios

International audienceBehind the appellation “modal methods”, for diffraction gratings, one can find a variety of methods sharing in common the development of the fields in terms of basis functions that can be either Fourier exponentials hence the name Fourier Modal Method (FMM), or polynomials leading to the family of Polynomial Modal Methods (Legendre, Tchebychev, and Gegenbauer). These approaches may not behave in the same way when dealing with gratings with extreme features such as a very low or very high filling ratios. In the present work, we address such a problem and compare the performances of the different Modal Methods

Analyse de scènes par une méthode du type "K2D" pour la manipulation de pièces en robotique avancée

Nous décrivons le système de vision stéréoscopique appliqué à la Robotique, utilisé au LIMSI. Ce système constitue l'essentiel du module de perception utilisé pour la manipulation d'objets. Les opérations d'assemblage automatique seront assurées par des capteurs d'efforts, l'information géométrique étant fournie par le module de vision. Les caractéristiques de ce système sont les suivantes : - utilisation de la méthode "K2D", - positions des caméras déterminées à partir des images de quatre points d'étalonnage, - angle de vision de la scène quelconque (30°-60°), - images de 256 x 256 x 4 bits, - les objets sont approximés par des polyèdres. Les images sont d'abord traitées afin d'extraire les contours. Puis les contours sont approchés par des segments de droites. L'algorithme hongrois est utilisé pour trouver les segments homologues. La précision des résultats est limitée principalement par les dimensions des pixels et par la précision de l'extracteur de contours

On a (2,2)-rational recursive sequence

We investigate the asymptotic behavior of the recursive difference equation yn+1=(α+βyn)/(1+yn−1) when the parameters α<0 and β∈â„Â. In particular, we establish the boundedness and the global stability of solutions for different ranges of the parameters α and β. We also give a summary of results and open questions on the more general recursive sequences yn+1=(a+byn)/(A+Byn−1), when the parameters a,b,A,B∈℠and abAB≠0

Structure and stability of Na+Xen clusters

International audienc