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The presence of fat within a hepatic lesion is unusual and can help to direct the radiologist's diagnosis. The aim of this iconographic review is to specify the various hepatic lesions that may contain fat and their appearance particularly on MRI. A histological correlation is also suggested for the most commonly found tumors. The identification of fat within a hepatic tumor, along with other radiological signs and reflection on the clinical and epidemiological context, can lead to a diagnosis being reached or suggested, with confirmation if necessary, by a pathological examination.

Background High frequency percussive ventilation (HFPV) combines diffusive (high frequency mini-bursts) and convective ventilation patterns. Benefits include enhanced oxygenation and hemodynamics, and alveolar recruitment, while providing hypothetic lung-protective ventilation. No study has investigated HFPV-induced changes in lung aeration in patients with early acute respiratory distress syndrome (ARDS). Methods Eight patients with early non-focal ARDS were enrolled and five swine with early non-focal ARDS were studied in prospective computed tomography (CT) scan and animal studies, in a university-hospital tertiary ICU and an animal laboratory. Patients were optimized under conventional “open-lung” ventilation. Lung CT was performed using an end-expiratory hold (Conv) to assess lung morphology. HFPV was applied for 1 hour to all patients before new CT scans were performed with end-expiratory (HFPV EE) and end-inspiratory (HFPV EI) holds. Lung volumes were determined after software analysis. At specified time points, blood gases and hemodynamic data were collected. Recruitment was defined as a change in non-aerated lung volumes between Conv, HFPV EE and HFPV EI. The main objective was to verify whether HFPV increases alveolar recruitment without lung hyperinflation. Correlation between pleural, upper airways and HFPV-derived pressures was assessed in an ARDS swine-based model. Results One-hour HFPV significantly improved oxygenation and hemodynamics. Lung recruitment significantly rose by 12.0% (8.5–18.0%), P = 0.05 (Conv-HFPV EE) and 12.5% (9.3–16.8%), P = 0.003 (Conv-HFPV EI). Hyperinflation tended to increase by 2.0% (0.5–2.5%), P = 0.89 (Conv-HFPV EE) and 3.0% (2.5–4.0%), P = 0.27 (Conv-HFPV EI). HFPV hyperinflation correlated with hyperinflated and normally-aerated lung volumes at baseline: r = 0.79, P = 0.05 and r = 0.79, P = 0.05, respectively (Conv-HFPV EE); and only hyperinflated lung volumes at baseline: r = 0.88, P = 0.01 (Conv-HFPV EI). HFPV CT-determined tidal volumes reached 5.7 (1.1–8.1) mL.kg-1 of ideal body weight (IBW). Correlations between pleural and HFPV-monitored pressures were acceptable and end-inspiratory pleural pressures remained below 25cmH20. Conclusions HFPV improves alveolar recruitment, gas exchanges and hemodynamics of patients with early non-focal ARDS without relevant hyperinflation. HFPV-derived pressures correlate with corresponding pleural or upper airways pressures. Trial registration ClinicalTrials.gov, NCT02510105. Registered on 1 June 2015. The trial was retrospectively registered. Electronic supplementary material The online version of this article (doi:10.1186/s13054-017-1924-6) contains supplementary material, which is available to authorized users.

Fibrodysplasia ossificans progressiva (FOP) is a rare disease characterized by the association of congenital bone abnormalities and extraskeletal ossification flare-ups occurring in muscles and fasciae. Early diagnosis is important to prevent ossification flare-ups, but some atypical presentations can lead to errors in diagnosis and therefore delay. Here, we report on a case of an atypical presentation of FOP in a girl, in whom prominent transverse reductional abnormalities delayed diagnosis. The patient developed extraskeletal ossifications and progressive fibrosis that led to motor restrictions. Since early diagnosis is important, we discuss the clinical presentations of FOP and the differential diagnoses.

One per cent of cases of mechanical occlusion of the small intestine are caused by internal hernias, the rarest type being an internal hernia through the broad ligament of the uterus, and representing approximately 5% of cases. While "conventional" treatment of mechanical occlusions of the small intestine is based on laparotomy, a laparoscopic approach is feasible in nearly half of cases, with an acceptable rate of morbidity. Preoperative diagnosis has for a long time been difficult but the usefulness has recently been emphasized of computed tomography. We report the cases of two patients who presented an internal hernia of the right broad ligament diagnosed with CT who afterwards underwent laparoscopic surgery.

CT imaging features of colitis in neutropenic patients Colitis in neutropenic patients presents with non-specific clinical findings including abdominal pain, fever, diarrhea and abnormal liver function tests. Four diagnoses are relatively more frequent: neutropenic enterocolitis, pseudomembranous colitis, intestinal GVHD and CMV colitis. Knowledge of their respective imaging features combined with epidemiological data frequently leads to the correct diagnosis. The purpose of this paper is to illustrate the imaging features of colitis in neutropenic patients.

Purpose. To review the histological features of 26 circumscribed liver lesions associated with liver capsule retraction and discuss the differential diagnosis while evaluating for the presence of fibrous stromal reaction. Materials and methods. Retrospective study performed between January 2005 and June 2008 including 26 patients: 18 males and 6 females, without history of cancer, aged between 42 and 82 years (mean age: 64.5 years), presenting with liver capsule retraction adjacent to a circumscribed liver lesion detected on CT or MRI. A single lesion was present in 17 patients, and multiple lesions were present in 9 patients. All liver lesions were biopsied with semi-quantitative evaluation of fibrous stromal reaction. Results. Twenty-one patients had benign or malignant liver tumors and 5 patients had confluent hepatic fibrosis. Twenty of 21 liver tumors were malignant (95.2%): 3 intra-hepatic cholangiocarcinoma, 17 cases of metastatic disease including colorectal carcinoma (n=8), bronchogenic carcinoma (n=1), pancreatic carcinoma (n=4), esophageal carcinoma (n=1), breast carcinoma (n=1), gallbladder carcinoma (1) and endocrine neoplasm of the pancreas (n=1), and 1 case of liver sclerosing angioma (n=1). There was no case of hepatoma. Excluding the 5 cases of confluent hepatic fibrosis, fibrous stromal reaction was present in 15 of 21 cases. Conclusion. The presence of capsular retraction next to a circumscribed liver lesion, while non-specific, is suspicious. In keeping with previous reports, metastases were frequently the cause and intrahepatic cholangiocarcinoma was the most frequent primary tumor. In patients with chronic hepatocellular disease, confluent fibrosis was a frequent etiology. The fibrous component of the underlying malignant lesion along with its subcapsular location appear to be determining factors in the development of capsular retraction.

In most cases, fibrolamellar hepatocellular carcinoma has specific and distinctive histopathological features that distinguish it from hepatocellular carcinoma. Magnetic resonance imaging can provide characteristic features to obtain a diagnosis of this entity. We report a case of fibrolamellar hepatocellular carcinoma with a radiological-pathological correlation in a 37 year-old man with chronic viral hepatitis B without cirrhosis who underwent right hepatectomy.

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The arteries and veins of the left vagus (VN) and left recurrent laryngeal (RLN) nerves from the thoracic inlet to the subaortic region are described following vascular casting with red colored latex in 6 adult fresh non-embalmed cadavers. In all specimens the anterior bronchoesophageal artery supplied at least one vessel to the VN and RLN in the subaortic region. For the RLN other arterial sources were arteries arising from the aortic arch in 1 specimen, the subclavian artery in 3 specimens, the first intercostal artery in 1 specimen, and the inferior thyroid artery in all specimens. For the VN other arterial sources were arteries arising from the aortic arch in 2 specimens and the inferior thyroid artery in 1 specimen. For both the VN and RLN the veins were located under the pleura and directed towards the internal thoracic vein anteriorly and the thoracic intercostal veins posteriorly. In conclusion, the inferior thyroid artery at the thoracic inlet for the RLN and the anterior bronchoesophageal artery are the more consistent vessels supplying the VN and RLN. Vascular damage occurring during mediastinal lymph node excision to the VN and RLN, especially in the subaortic region, may explain postoperative vocal fold paralysis.

a lipomatose est une complication rare de la corticotherapie au long cours. Les localisations preferentielles sont le mediastin, la region retrooculaire et l’espace epidural rachidien. Dans ce dernier cas, les symptomes sont peu specifiques. Un tableau de compression medullaire aigue peut parfois survenir en cas de tassement vertebral associe, comme nous l’illustrons dans cette observation.

Une prise de Gadolinium permettait de prevoir constament un effet favorable des anti-inflammatories.

Dynamic MRI of the pelvis was performed in 16 young nulliparous, normally continent women. The examinations were performed in the dorsal decubitus position. Using Turbo-Flash scans (acquisition time: 2.1 sec), sagittal images were obtained at rest and with maximal pelvic straining. The sacral promontory-subpubic (PSP) and the subpubic-subsacral axes (SPSS) measured respectively 80.5 degrees and 30 degrees in relation to the horizontal plane, without a statistically significant difference between rest and straining. A marked deformation of the posterior wall of the bladder was observed in 13 cases and the bladder neck was frontally deformed in 10 cases. With straining, the base of the bladder did not descend beyond 15 mm below the SPSS, and the cervix stayed at least 14 mm above the SPSS. These were established as the normal criteria for pelvic assessment. 20 multiparous patients (mean age 65 years), referred for urinary stress incontinence and/or prolapse, were investigated using the criteria previously established. The PSP, SPSS, and vaginal angle measured 80.95 degrees, 30.57 degrees, and 69.69 degrees respectively in relation to the horizontal. No statistically significant difference was detected between straining and rest conditions. The angle of the uterus in relation to the horizontal was 57.36 degrees at rest and 65.90 degrees in straining with a difference that was statistically significant. In six patients, the base of the bladder descended more than 1.5 cm while straining and in seven patients the cervix descended at least 1.4 cm below the SPSS while straining, both statistically significant differences. Overall, between our control and study populations, there were no significant differences between PSP and SPSS measured on straining and at rest. However, differences were detected in the vaginal angle, bladder-base position, and cervical position. These results suggest the potential substitution of MRI for colpocystography.

L'architecture, les mecanismes de la statique et de la dynamique du pelvis rendent difficiles les indications therapeutiques en cas d'incontinence urinaire et/ou de prolapsus, soulignant l'interet de bilans precis statiques et dynamiques, en particulier chez les patientes multi-operees ou les modifications anatomiques sont nombreuses. A cote de ses performances purement morphologiques, l'IRM, en utilisant des sequences rapides, est surement un examen d'avenir dans l'expertise des desequilibres de la statique pelvienne. Si la realisation de l'exploration en decubitus dorsal est un inconvenient de depart a ce jour incontournable, l'absence d'opacification pelvienne instrumentale rend l'IRM beaucoup plus physiologique que le colpocystogramme. Apres avoir etabli des criteres de normalite, nous avons tente chez des patientes affectees d'une incontinence et/ou d'un prolapsus de mettre en evidence des criteres predictifs pour une decision therapeutique. Les limites que nous avons rencontrees sont peut etre a rapporter a la population (heterogeneite et importance des antecedents). L'impossibilite de visualiser avec precision le col vesical et la filiere ano-rectale, contrairement a l'avis d'auteurs anterieurs, [6] constitute egalement un handicap. La substitution de l'IRM au colpocystogramme nous apparait donc aujourd'hui prematuree. Mais la technique, tres evolutive, est susceptible d'amendements rapides, notamment par la majoration de la resolution spatiale. Sa place dans les bilans de routine devra surement etre rediscutee bientot.

Magnetic resonance imaging (MRI) allows accurate assessment of Crohn's disease (CD), but requires gadolinium injection. Diffusion-weighted (DW)-MRI yields comparable performances in small bowel CD. We compared the accuracy of DW-MR enterocolonography (MREC) and the magnetic resonance index of activity (MaRIA), and performed an external validation of the Clermont score in assessing inflammation in CD.This was an observational prospective study of a single-center cohort. A total of 130 CD patients underwent consecutively MREC with gadolinium injection and DWI sequences between July 2011 and December 2012.Of the 848 evaluated segments (small bowel=352, colon/rectum=496), 175 (20.6%) were active (small bowel=111, colon/rectum=64) defined as MaRIA ≥7. Using a receiver operating characteristic (ROC) curve, we determined an apparent coefficient of diffusion (ADC) threshold of 1.9 × 10(-3) mm(2)/s that yielded a sensitivity and a specificity in discriminating active from nonactive CD of 96.9% and 98.1%, respectively, for the colon/rectum, and 85.9% and 81.6%, respectively, for the ileum. ADC was better correlated to MaRIA ≥7 than related contrast enhancement obtained with injected sequences (P0.001). The Clermont score (=1.646 × bowel thickness-1.321 × ADC+5.613 × edema+8.306 × ulceration+5.039) was highly correlated with the MaRIA (rho=0.99) in ileal CD but not in colonic CD (rho0.80). Interobserver agreement was high with regard to ADC measurement (correlation0.9, P0.001, and concordance0.9, P0001).DW-MREC is a reliable tool to assess inflammation in colonic (ADC) and ileal (Clermont score) CD and its use in daily practice would avoid gadolinium injection.

The ovaries can be affected by a vast variety of tumours, which may be benign or malignant, solid or cystic. Although ultrasonography is often the first examination performed in the evaluation of gynaecological conditions, magnetic resonance imaging is nowadays the most accurate imaging technique in the characterization of ovarian masses. Once the ovarian origin of a pelvic mass has been determined, the detection of any fibrous component within the lesion significantly reduces the spectrum of aetiologies that should be considered. Fibrotic tissue usually displays marked low-signal intensity on T2-weighted sequences at MRI, and enhancement is mostly moderate after intravenous administration of gadolinium chelates. This review aims to provide the main diagnoses to consider at MRI whenever an ovarian tumour, both purely solid or solid and cystic, contains a fibrous component, even if minimally abundant. The corresponding key imaging features are provided.

The purpose of this study was to determine the following: whether the arterial supply of a normal appendix is visible with Doppler sonography; whether the physiologic vasodilatation that accompanies childhood appendicitis is visible; what Doppler patterns appear once necrosis of the appendix has occurred; what Doppler shifts are visible with chronic, recurrent appendicitis; and whether other conditions in the right lower quadrant can mimic the Doppler sonographic patterns of appendicitis.Twenty-five fasting patients without abdominal pain or intestinal disease and 45 patients (1-25 years old; mean, 8 years old) with right lower quadrant pain and suspected appendicitis were examined sonographically, using 5- and 7-MHz linear, color, and pulsed Doppler transducers. Arterial signals were sought within the appendix and neighboring tissues, counted, and classified as sparse (1-2), moderate (3-4), or abundant (4). The resistive index (RI) was measured. Thirty patients who underwent surgery were retained for surgical and pathologic correlation, and only they formed the appendicitis study.A normal appendix was found in 10 patients. Doppler shifts were sparse, and diastolic flow was low or absent (RI, 0.85-1). Acute uncomplicated appendicitis was found in 13 patients, who had abundant color Doppler signals throughout most of the appendix, with high diastolic flow (RI, 0.40-0.77; mean, 0.54). Acute necrotic appendicitis with perforation was found in 11 children, eight of whom showed no signals in the necrotic area at the tip. Few or no signals were seen in the remainder of the appendix (RI, 0.33-0.90; mean, 0.54). In two patients, signals were abundant in the tissues surrounding the appendix. Recurrent or chronic appendicitis was found in three patients, previously diagnosed as having Crohn's disease, psychosomatic illness, or nonspecific abdominal pain. The appendix had Doppler signals confined to the tip (RI, 0.63-0.83; mean, 0.75). Other diagnoses were found in three patients, in whom the appendix was not seen. There were abundant color signals in the intestinal wall and adjacent tissues in the right lower quadrant. Two patients had Crohn's disease, and the third had an unsuspected early pregnancy. The appendix was normal in all.Acute appendicitis is accompanied by inflammatory hypervascularity reflected as an increased number of color signals and higher diastolic Doppler shifts as compared with those found in normal persons. No Doppler shifts are identified in areas of appendiceal ischemia. Other acute inflammation in the right lower quadrant also produces numerous Doppler shifts with high diastolic flow, as does ovulation. Care must be taken to identify the source of these Doppler signals. The changing vascularity of healing, recurrent, and chronic appendicitis promises to further our understanding of the pathogenesis and evolution of this disease.

Resume Introduction Le pronostic de l’anorexie mentale (AM) est severe (deces dans 2 a 5 % des cas). L’AM entretient des liens etroits avec des acces de boulimie. Observation Une femme anorexique mentale de 25 ans a ete hospitalisee pour syndrome occlusif avec vomissements, la presence d’une contracture abdominale, l’absence de bruits hydroaeriques et un arret des matieres et des gaz. La biologie etait normale. Le scanner abdominal mettait en evidence une volumineuse distension gastrique. Le diagnostic de syndrome occlusif fonctionnel etait retenu. Sous traitement medical et surveillance en reanimation, la distension gastrique s’est resolue progressivement. Discussion Les periodes de restriction alimentaire de l’AM sont entrecoupees d’acces boulimiques a l’origine de complications digestives parfois severes. Les anomalies de la motilite gastrique peuvent aboutir a des distensions majeures de l’estomac avec risque de perforation. La survenue de douleurs abdominales en cas d’AM au decours d’un acces boulimique doit faire evoquer le diagnostic de distension gastrique aigue avec risque majeur de perforation.

SummaryBackground Whether diffusion-weighted imaging (DWI)-MRI is of value in detecting and assessing inflammation of ileal Crohn's disease (CD) remains poorly investigated. Aim To compare DWI-MR enterography (MRE) with conventional MRE in estimating inflammation in small bowel CD, to determine an apparent diffusion coefficient (ADC) threshold to differentiate active from non-active lesions and to assess inter-observer agreement. Methods Thirty-one CD patients from the Clermont-Ferrand IBD unit with ileal involvement were consecutively and prospectively included between April and June 2011. All patients underwent DWI-MRI to detect the digestive segment with the most severe lesions, which was then used to calculate the ADC. Qualitative and quantitative results were compared with conventional MRE including MaRIA (Magnetic Resonance Index of Activity) score calculation and independent activity predictors (wall thickening, oedema, ulcers). Each examination was interpreted independently by two radiologists blinded for clinical assessment. Results Seventeen patients (54.8%) had active CD as defined by the MaRIA score ≥7. DWI hyperintensity was highly correlated with disease activity evaluated using conventional MRE (P = 0.001). Qualitative analysis of DW sequences determined sensitivity, specificity, positive predictive value and negative predictive value as 100%, 92.9%, 94.4% and 100% respectively. Quantitative analysis using a cut-off of 1.6 × 10−3 mm²/s for ADC yielded sensitivity and specificity values of, respectively, 82.4% and 100%. Inter-observer agreement was high with regard to DWI hyperintensity (κ = 0.69, accuracy rate = 85.7%) and ADC (correlation = 0.74, P

Finite element modelling of the human lumbar vertebral column employs data-processing procedures for study of the linear and nonlinear elasticity of materials such as are currently used in mechanics or in civil engineering. Thanks to developments in computer science, requiring a close collaboration between doctors and engineers, we put forward in this preliminary study a linear computerised model of the lumbar column comprising 4824 meshes and 6813 nodes. By reducing the simplificatory hypotheses and integrating new parameters, this model as developed is capable of important clinical applications in surgery and ergonomics.

Posterior reversible encephalopathy syndrome (PRES) is a rare but severe condition of the central nervous system. It develops in a variety of clinical settings and it has diverse patterns of expression, which can sometimes make diagnosis difficult. Characteristic features are often demonstrated on computed tomography imaging and/or magnetic resonance imaging, meaning that when there is a suspicious clinical picture, this diagnosis should suggest itself. However, clinicians should be aware of some of the less typical features in order to more fully understand this condition, in which early treatment is key to good clinical progress.

In haematology units, acute abdominal symptoms are common and often challenging for the clinician in charge. Two haematological conditions that may induce specific diagnoses are of particular concern: neutropenia and haematopoietic stem cell transplantation. Clinical and biological manifestations, including abdominal pain, fever, diarrhoea, hepatic cytolysis, or cholestasis are often non-specific. Computed tomography is often the primary imaging screening technique performed in such patients, as it is widely available, performs well for this indication, and may demonstrate evocative findings. The aim of this review is to provide the spectrum of specific diagnoses encountered and the corresponding key CT features in patients presenting with acute abdominal disorders following neutropenia and/or haematopoietic stem cell transplantation.

Opto-electronic systems utilising measurement of displacement of skin markers allows study of movement in the living subject. The authors have used this method in a kinematic study of the thoracic and lumbar spine measuring the displacement of skin markers placed over the spinous processes. It was possible to approach the physiological state of these complex movements once the apparatus had been calibrated to the correct level, and the error margins minimised. Repeated measurements confirmed the reliability of this method even if movement of the skin with respect to the bony reference points introduced some margin of error. Three dimensional displacement of the vertebrae were measured during voluntary movements of the spine demonstrating the complex geometry. Since opto-electronics are non-invasive they constitute an important advance in the study of the kinematics of the spine.

The infratemporal fossa and its contents (particularly the pterygoid muscles) is a region difficult to explore, in spite of its importance in odontostomatological pathology. In order to reduce the indications that justify examination by computed tomography and magnetic resonance imaging, for reasons of economy of health, the authors describe by application of orientated anatomical slices the way in which ultrasonography can be performed. Only the posterior approach between the mandible laterally and the mastoid process medially provided consistently adequate exploration of the infratemporal fossa and the pterygoid muscles.

According to the ultrasound and MRI findings, supported by planned dissections, the female perineum is organised around the musculofascial system converging towards the fibrous structure of the central perineal tendon (CPT). Behind the CPT the fascial layers form part of a fibrous assembly extending from the ventral surface of the sacrum to the anal complex, prolonging the direction of the sacral concavity downwards and forwards. On the other hand, in front of the CPT the fasciae fuse to form two aponeurotic bands circumscribing the urogenital fossa. The fascial system is reinforced cranially by the structures of the hypogastric sheath and the uterosacral ligaments. The weak point of the urogenital fossa is partly filled by the urethral-clitoridal-vulvar complex. The perineum so formed plays a cardinal role in stabilising the pelvic viscera. Stress is placed on the firmness of the posterior perineum, a key element in pelvic stability. The posterior perineum is often involved in pathological conditions and a good acquaintance with these structures is essential in defining therapeutic indications.

The authors have studied the relationship between anatomic and CT sections of the lateral pterygoid muscle in 39 anatomic specimens. Good superimposition of the images was found, which seems important in neoplastic invasion of the infratemporal fossa and which may lead to a pathogenic interpretation of the algo-dysfunctional syndrome of the masticatory apparatus.

To explain surgical findings, we studied the anatomy of the human humeral medullary canal on a series of 28 bones in 16 patients and 9 dried bones. A methodology is described to find angle of medullary canal on CT scans regarding to an epicondylar reference axis. We found a constant tri-dimensional spiral shape of the medullary canal in the distal part of the bone. The relations between this first description and the literature are discussed.

Background: Patients with severe hyponatremia have a high risk for centropontine myelinolysis (CPM) during treatment, but the incidence rate and risk factors have not been well-assessed. Methods: This study was conducted in a medical intensive care unit (ICU) of a university teaching hospital. All patients with a serum sodium concentration < 120 mmol/l and a serum osmolality level < 250 mosmol/kg upon ICU admission were enrolled in this prospective study and were included if they underwent a baseline brain computerized tomography scan (CT scan) and a follow-up brain magnetic resonance imaging 1 month after admission. The diagnosis of CPM was based on cerebral magnetic resonance imaging findings, i.e. Tl-weighted images with T2-weighted images showing hyperintense signal in the corresponding areas which were not apparent on the initial cerebral CT scan. Results. Of the 22 patients included, 12 were considered as having acute hyponatremia and 8 were chronic alcoholics. In 12 patients, the increase in serum sodium level was < 12 mmol/l in any 24-hour period. CPM was diagnosed in 7/22 patients (31.8%) and was asymptomatic in 4 of them. CPM was present in 4 patients with acute hyponatremia and in 4 chronic alcoholics. It was associated with a lower baseline potassium level (p = 0.05) and NaCI administration during the first 24 hours (p = 0.005). However, non-acute hyponatremia, chronic alcoholism and rapid correction of serum sodium did not appear as risk factors. Conclusion: The incidence rate of CPM following severe hyponatremia is high and can develop even when there is a slow correction of serum sodium level. Hypokalemia is a predisposing factor.

The utility of the inferior oblique m. radioanatomical study by a FLASH 3D sequence in magnetic resonance imaging (MRI). Twenty eyes (ten healthy volunteers aged 21-32 years, without any history of significant ocular pathology) were explored by MRI (1 Tesla; cranial coil) and comparisons were made between spin echo (SE) T1 sequence (through the neuro-ocular and coronal planes; thickness of slices = 3 mm) and a gradient echo FLASH 3D sequence (thickness of slices = 1 mm). This enabled a mm by mm reformation of the inferior oblique m through the frontal-oblique plane, made possible by new SE T1 sequences through the same plane. Position, height, and signal of the m. were estimated. The mean frontal angle formed by the muscle and the sagittal axis measured 29 degrees for the right eye and 27 degrees for the left eye. The muscle was always identifiable in the reformation despite its thin dimensions: 1.9 mm (1.5 - 2.8) on the right and 2 mm (1.7 - 2.5) on the left, in low signal silhouetted by the high signal of orbital fat. Thus, thanks to mm by mm reconstructions using FLASH 3D sequence, a good radioanatomic study of the inferior oblique m. by MRI is possible. This could be useful particularly for the strabismus of children.

The influence of various modes of carrying a load of 16 kg (15.69 DaN) on the static positioning of the pelvic girdle and the thoracic and lumbar segments of the spine was examined in seven male subjects. The displacement of cutaneous markers attached to easily palpable skeletal landmarks was recorded using 4 CCD cameras; the data acquired were analysed using an optoelectronic technique (SAGA3). The subjects stood upright on an AMTI biomechanical force platform, from which the ground reaction forces enabled displacements of the centre of gravity axis and thus the moment of the mass carried to be determined. The modes of load carriage examined were: 1) in a case in the left hand; 2) in a case in the right hand; 3) equally in two cases; 4) on the head; 5) in a rucksack; and 6) in an anterior bag. The results showed displacements of the pelvic girdle, the caudal and cranial lumbar segments, and the caudal and cranial thoracic segments in the three orthogonal planes (sagittal, frontal and transverse). The influence of the moment created by the load was seen in the statokinesigrams. The use of external markers using an optoelectronic technique, in association with the ground reaction forces, enables the mode of load carriage to be determined. The results show that the influence of the moment exerted by the mode of load carriage on the gravity axis has important ergonomic consequences.

The motion of the thoracic and lumbar spine segments was analysed by mean of the skin landmarks method in 14 volunteers (7 males, 7 females). The results demonstrated that there was no significant difference between men and women and there was either facilitation or limitation of the motion of the characteristic landmarks of spinal segments during trunk motion in perpendicular planes. The mobility of spinal segments was associated with pelvic girdle motion in order to obtain the planned amplitude, and varied with hip joint abduction. The analysis of the precise mechanisms of relaxing or stretching of the pelvivertebral musculo-ligamentous structures constitutes a large field of investigation that necessitates the study of other lower limb postures and the use of robotic techniques.

This study describes a method of tracking of human body limbs from a monocular sequence of perspective images. These objects and the associated articulations must be modelled. The principle of the method is based on the interpretation of image features as the three-dimensional perspective projections points of the object model and an iterative process method to compute the model position in accordance with the analysed image. This attitude is filtered (Kalman filter) to predict the model position relative to the next image of the sequence. The image features are extracted locally according to the computed prediction. Tracking experiments, illustrated in this study by a leg cycling sequence, have been conducted to demonstrate the viability of the approach.

The overall movement of the trunk is made up of two components, namely the movements of the pelvic girdle and the vertebrae. In the frontal plane, the amplitude of the pelvic movements appears to be relatively limited compared to the vertebral column whereas the pelvis makes the major contribution to the total rotational movement in the axial plane.

Optical techniques using single wavelength lasers allow precise study of the superficial displacements of deeper anatomical structures through direct mechanical pull. Two techniques have been used in this study: 1. Double exposure speckle photography. Since 1980 the relationship between the surface displacements and minimal traction applied to the transverse processes of the spine, either unilateral or bilateral, was studied in an attempt to simulate muscular action exerted at this level. 2. Computerised speckle interferometry. This allowed analysis of the deformations between the lumbar vertebrae under vertical compression, shear or torsion outside the usual anatomical planes. This preliminary study outlines the mechanical behaviour and the plasticity of the vertebral structures but has been performed on only a few anatomical specimens thus not allowing statistical analysis. This would require a larger series.

There has been a progressive growth of clinical, anatomical, technical and biomechanical knowledge of the spine which has emerged from both specific and collaborative efforts of many investigators. In the same way many distinguished contributors have at various times elaborated the analysis of vertebral trauma and their names appear in the References to this paper.

Under static loading during weight-lifting, the lumbosacral spine essentially exhibits horizontalisation of the base of the sacrum (superior plateau of S1). We have attempted to elicit the mechanism of this horizontalisation by means of radiographs. These do not demonstrate any movements of the sacroiliac joints or plasticity of the hip bones. However, a symmetrical rotation of the hip joints conditions a retroversion of the pelvic girdle which explains the horizontalisation of the upper sacral plateau. This fixation of the block of the pelvic girdle is under muscular control, so that this mechanism can be improved by appropriate training.

Objectifs Exposer nos resultats du stenting de syndromes caves superieurs neoplasiques. Materiels et methodes Etude retrospective monocentrique (2000-2007) : 21 hommes, 13 femmes, 44 a 81 ans (moyenne : 60,5), affectes de 26 cancers bronchiques non a petites cellules (76 %), 6 cancers bronchiques a petites cellules (17 %), ou de metastases d’adenocarcinomes mammaires (2,6 %). Une thrombose cruorique etait associee chez 22. Resultats Le stenting pouvait etre effectue dans tous les cas. La resolution des symptomes etait constante en moins de 24 heures. Vingt-quatre patients decedaient apres 13 a 525 jours (moyenne : 66), dont 4 dans les 8 jours suivants le geste. Cinq cas de recidive du syndrome cave (15 %) etaient traites par un deuxieme geste (4 restenoses, 1 fracture de stent). Les taux de permeabilite immediate puis retrouve au terme du suivi etaient respectivement de 85 % et 100 %. Conclusion Le traitement endovasculaire du syndrome cave superieur d’origine neoplasique, contribuant largement a la qualite de la survie, est fiable, sur et perenne.

Ce travail global a permis d'observer des elements qui doivent etre analyses plus precisement par des investigations complementaires : - influence d'autres positions des art. coxo-femorales (adduction, rotations mediale ou laterale, flexion), ou des genoux (flexion), sur la cinematique de la colonne lombaire et thoracique ; - analyse opto-electronique des variations angulaires des capteurs au cours de la realisation d'un mouvement du tronc dans un plan anatomique ; - determination des mecanismes precis et des structures musculo-ligamentaires concernees par les techniques anatomiques, de comportement des materiaux et de robotique.

The haemangioma, the most common non-cystic hepatic lesion, most often discovered by chance, may in certain situations raise diagnostic problems in imaging. In this article, the authors first demonstrate that the radiological appearance of the hepatic haemangioma, in its typical form, is closely related to three known histological sub-types. They then show that certain atypical features should be known in order to establish a diagnosis. They also observe the potential interactions between the haemangioma, an active vascular lesion, and the adjacent hepatic parenchyma. Finally, they discuss the specific paediatric features of hepatic haemangiomas and illustrate the case of a hepatic angiosarcoma.