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Biomedical subjects

G Sebag

Publications and source records attributed to G Sebag.

At least 19 recordsLinked to original sources

Third-trimester fetal MRI in isolated 10- to 12-mm ventriculomegaly: is it worth it?

OBJECTIVE: The justification for magnetic resonance imaging (MRI) in isolated mild ventriculomegaly remains controversial. This study was undertaken to evaluate the contribution of third-trimester MRI in isolated 10- to 12-mm fetal ventriculomegaly. DESIGN: Observational prospective cohort study. SETTING: Universitary prenatal reference centre. POPULATION: From February 2000 to May 2005, we prospectively collected data concerning fetuses referred to us for cerebral MRI following detection of ventriculomegaly by ultrasound scan (n= 310). METHODS: Among these, we identified and analysed those cases in which ventriculomegaly was isolated and did not exceed 12 mm in ultrasound examinations prior to MRI scan (n= 185). MAIN OUTCOME MEASURE: Cases in which MRI provided additional information that was likely to have an impact on prenatal management were detailed. RESULTS: During the study period, 310 MRI were performed because of fetal ventriculomegaly. Hundred and eighty-five were suspected to be isolated 10- to 12-mm ventriculomegalies in ultrasound scan and formed our database. MRI confirmed the 10- to 12-mm isolated fetal ventriculomegaly in 106 cases (57.3%) and found other abnormalities in 5 (4.7%) of these 106 cases. MRI found ventricular measurement to be less than 10 mm in 43 cases (23.3%) and more than 12 mm in 36 cases (19.4%). Among these 36 fetuses with ventricle size more than 12 mm, 6 (16.7%) had other abnormalities, whereas MRI did not find other abnormalities in the 43 cases with ventricle size below 10 mm. CONCLUSION: Before advantages of MRI to ultrasound examination can be demonstrated, it seems reasonable that MRI should remain an investigational tool, restricted to selected clinical situations in which the results are expected to modify case management. Where ultrasound scan suspects isolated ventriculomegaly of 10 to 12 mm, our data suggest that when the finding is confirmed with MRI this could be expected in around 5% of cases. Therefore, the policy of routine MRI in such cases should depend on prenatal centres' priorities.

Brain Edema↗

Automated analysis of MR image of hip: geometrical evaluation of the Legg-Calve-Perthes disease.

This study proposes semi-automatic determination of geometrical features in hip magnetic resonance (MR) images in order to evaluate the Legg-Calvé-Perthes disease (LCPD). Nine anatomical points on a hip image are selected by a clinician; then eight geometrical indexes of the hip joint are calculated: acetabulum head index (AHI), Wiberg angle (VCE), inner acetabular coverage angle (VCI), acetabular inclination angle (HTE), femoral shaft-neck angle (CC'D), circularity (C), convex deficiency factor (CDF) and pillar height deficiency factor (HDF) for the head region. The geometrical parameters are evaluated on 46 hip images of young patients with unilateral LCPD: 23 images concern the affected hip and 23 the unaffected hip. The extraction of the region of interest is done with a seeded region growing method. All the data were centered and reduced, and were subjected to principal component analysis. Supervised classification is applied with discriminant analysis and k-nearest neighbours classification. The AHI appears to be the best discriminant attribute (maximum between-class variance ratio). Cross-validation tests indicate that we can at most reduce the parameters to five (AHI, CC'D, DHF, DCF and VCE). The classification error rate for the linear discriminant method is 12.5%.

Automation↗

Prenatal diagnosis of a cystic type IV sacrococcygeal teratoma mimicking a cloacal anomaly: contribution of MR.

OBJECTIVE: To report a case of pelvic midline cystic mass in a female fetus without visibility of the rectum and which is not a cloacal anomaly. METHODS: Ultrasound (US) and magnetic resonance imaging (MRI) were performed respectively at 27 and 27.5 weeks' gestation and the findings of these examinations were compared with post-mortem examination after termination of pregnancy (TOP). RESULTS: US showed a pelvic midline cystic mass in a female fetus with mild enlargement of the left ureter and renal pelvis. MRI did not show the T1 hypersignal of meconium in the rectum. The analysis of MR findings were suggestive of the diagnosis of a sacrococcygeal teratoma. Pregnancy was terminated because of the possibility of severe sphincterial disorders and the fetopathological examination confirmed this diagnosis. CONCLUSION: This observation illustrates the diagnostic problems generated by the detection of a pelvic midline cystic mass in a female fetus. The absence of visibility of the T1 hypersignal of the meconium in the rectum is traditionally supposed to be highly suggestive of a cloaca, but may also be explained by the emptiness of the rectum, compressed by the mass.

Adult↗

[Gartner's cyst communicating with the bladder and vagina with associated complete vaginal diaphragm].

Gartner's duct cyst is a relatively common benign cystic lesion and represents embryologic remnants of Wolffian ducts. These cysts are usually small and asymptomatic and have been reported to occur in as many as 1% of all women. We report a case of a 30 month old baby presenting with recurrent urinary tract infection and Gartner's duct cyst communicating with the vagina and bladder with associated complete vaginal diaphragm. The diagnosis of Gartner's duct cyst was suggested by pelvic ultrasonography and MR imaging. Vaginal diaphragm and communication between the Gartner's cyst, the bladder and vagina were established during cystoscopy and vaginoscopy.

Child, Preschool↗

[Low bone mineral density in children with Crohn's disease].

UNLABELLED: Recent studies have reported low bone mineral density in children with Crohn's disease. The aims of this retrospective study were to quantify its frequency and to search for risk factors. POPULATION AND METHODS: Bone mineral density of 29 children with Crohn's disease was measured by dual-energy X-ray absorptiometry. All the children were taking calcium and vitamin D, during all the follow-up. RESULTS: Osteoporosis (Z-score < or = -2.5 S.D.) was found in 38% of the children, and osteopenia in 38% (Z-score between -1 and -2.5 S.D.). Low bone mineral density was correlated with age, suggesting it begins with puberty. Daily corticosteroid exposure was significantly higher for patients with osteoporosis. Disease severity measured with Harvey-Bradshaw index and exposure to immunosuppressive drugs were almost statistically significant. Sex, height, duration and site of disease, nutritional assistance exposure were not associated with low bone mineral density. CONCLUSION: This study confirms the high frequency of low bone mineral density in children with Crohn's disease, mainly during puberty. Corticosteroid exposure is a risk factor, and the disease severity, a probable one (non significant). New treatment strategy has to be defined to prevent and to treat this complication.

Absorptiometry, Photon↗

Isolated pericardial effusion in the human fetus: a report of three cases.

OBJECTIVE: Our objective was to determine the possible underlying etiologies and outcome in isolated fetal pericardial effusion. METHODS: Doppler fetal echocardiography allowed the diagnosis of pericardial effusion in three patients and revealed the etiology in two. RESULTS: We present the findings in three cases of isolated pericardial effusion. In the first, the pericardial effusion was a manifestation of trisomy 21 associated with a myeloproliferative disorder. In the second, the pericardial fluid collection was the first sign of an autosomal recessive disease, idiopathic infantile arterial calcification. The third case was remarkable because of the spontaneous resolution of a large pericardial fluid collection. CONCLUSION: Isolated fetal pericardial effusion covers a wide spectrum of etiologies from severe genetic and chromosomal diseases to transient forms.

Adult↗

Fetal cerebral cortex: normal gestational landmarks identified using prenatal MR imaging.

BACKGROUND AND PURPOSE: Few investigators have analyzed the MR imaging patterns of fetal gyration. Our purpose was to establish, with a large prospective series, the normal sulcation landmarks according to gestational age by using in utero MR imaging and to correlate our findings with established neuroanatomic timetables. METHODS: A standardized fetal cerebral MR examination was performed in 173 normal fetuses at 22 to 38 weeks' gestation. Eight T1- and T2-weighted coronal, axial, and sagittal slices were obtained for each fetus and systematically analyzed. The sequential development of the different fissures and sulci of the cerebral cortex with respect to gestational age were tabulated. RESULTS: Sulcation of the medial, lateral, and inferior surfaces of the brain was depicted, and a timetable for the MR depiction of the primary and secondary sulci was established for the 22- to 38-week gestational period. This timetable was in good agreement with the neuroanatomic standards of reference, with a mean lag time of 1 week. CONCLUSION: This analysis of fetal brain sulcation in a large series of fetuses contributes to a better understanding of the maturation of the fetal cortex on MR imaging studies. It furthermore provides a standard of reference that can be used to assess the normality of fetal sulcation and to diagnose gyrational abnormalities with prenatal MR imaging.

Cerebral Cortex↗

Multicenter prospective study of children with sickle cell disease: radiographic and psychometric correlation.

After obtaining familial informed consent, between January 1996 and July 1997, 173 children (5 to 15 years old) with sickle cell disease were enrolled in a prospective multicenter study using blood screening, transcranial Doppler ultrasonography (n = 143), cerebral magnetic resonance imaging (n = 144), and neuropsychologic performance evaluation (n = 156) (Wechsler Intelligence tests WISC-III, WIPPSI-R), which were also performed in 76 sibling controls (5 to 15 years old). Among the 173 patients with sickle cell disease (155 homozygous for hemoglobin SS, 8 sickle cell beta0 thalassemia, 3 sickle cell beta+ thalassemia, 7 sickle cell hemoglobin C disease SC), 12 (6.9%) had a history of overt stroke, and the incidence of abnormal transcranial Doppler ultrasonography (defined as mean middle cerebral artery velocity > 200 cm/sec or absent) was 8.4% in the overall study population and 9.6% in patients with homozygous sickle cell anemia The silent stroke rate was 15%. Significantly impaired cognitive functioning was observed in sickle cell disease patients with a history of stroke (Performance IQ and Full Scale IQ), but also in patients with silent strokes (Similarities, Vocabulary, and Verbal Comprehension). However, infarcts on magnetic resonance imaging were not the only factors of cognitive deficit: Verbal IQ, Performance IQ, and Full Scale IQ were strongly impaired in patients with severe chronic anemia (hematocrit < or = 20%) and in those with thrombocytosis (platelets > 500 x 10(9)/L). Multivariate logistic regression analysis showed that abnormal magnetic resonance imaging (odds ratio [OR] = 2.76) (P = .047), hematocrit < or =20% (OR = 5.85) (P = .005), and platelets > 500 x 10(9)/L (OR = 3.99) (P = .004) were independent factors of cognitive deficiency (Full Scale IQ < 75) in sickle cell disease patients. The unfavorable effect of low hematocrit has already been suggested, but this is the first report concerning an effect of thrombocytosis and showing that silent stroke alone is not a factor of cognitive deficit when not associated with low hematocrit or thrombocytosis. The effect of hydroxyurea, which is known to increase hematocrit and decrease platelet count, on cognitive functioning of sickle cell patients should be evaluated prospectively.

Adolescent↗

Laparoscopic Duhamel procedure. Management of 30 cases.

BACKGROUND: Between February 1995 and June 1998, 30 laparoscopic Duhamel pull-through procedures were performed in our department. METHODS: Our main aim was to prove the feasibility of the laparoscopic abdominal Duhamel procedure for different localizations of Hirschsprung disease. We used one camera port and three working ports. The sigmoid colon and posterior rectum were mobilized laparoscopically. A standard posterior colo-anal anastomosis was fashioned and a stapler was used for the anterior anastomosis. The top of the rectum was then closed by endo stapler under laparoscopic vision. RESULTS: Thirty patients underwent laparoscopic surgery for this procedure. Three laparoscopic procedures were converted because of technical difficulties. The operative time was 100-330 mn. Oral feeding was started at a mean postoperative time of 2.5 days. Mean postoperative hospitalization was 9 days. Early postoperative complications included 1 anastomotic leak, 1 retrorectal abscess, 2 urinary infections, and 1 evisceration (after conversion). No enterocolitis or enterocolitis-like symptoms were noted. All patients now have daily spontaneous bowel movements. CONCLUSION: The laparoscopic Duhamel procedure can be performed safely, giving good results.

Anastomosis, Surgical↗

Blind protected specimen brush and bronchoalveolar lavage in ventilated children.

OBJECTIVE: To determine whether nonbronchoscopic protected specimen brush (PSB) and bronchoalveolar lavage (BAL) are contributive for diagnosing ventilator-associated pneumonia in mechanically ventilated children. DESIGN: Prospective study. SETTING: Fifteen-bed pediatric intensive care unit in a university hospital. PATIENTS: A total of 103 mechanically ventilated children, ranging in age from 7 days to 8.8 yrs, most with a high clinical suspicion for bacterial pneumonia. INTERVENTIONS: All the children underwent nonbronchoscopic PSB and BAL. Nonbronchoscopic PSB was performed with a plugged double-sheathed brush and BAL with a double-lumen plugged catheter. Endotracheal secretions and blood cultures were also collected. Open-lung biopsy was performed for any child who died within 7 days after the inclusion in the study, according to the parental consent. MEASUREMENTS AND MAIN RESULTS: The PSB specimens were submitted for bacteriologic quantitative culture (positive threshold, 10(3) colony-forming units [cfu]/mL). The BAL samples were processed for microscopic quantification of the polymorphonuclear cells containing intracellular bacteria (positive threshold, 1%) and quantitative culture (positive threshold, 10(4) cfu/mL). According to diagnostic categories based on clinical, biological, radiologic, and pathologic criteria, 29 children had bacterial pneumonia and 64 did not Ten children were classified as having an uncertain status. Of the 29 children with bacterial pneumonia, 26 (90%) met one of the following three criteria: a) PSB specimen culture, > or =10(3) cfu/mL; b) intracellular bacteria in cells retrieved by BAL, > or =1%; and c) BAL fluid culture, > or =10(4) cfu/mL. In contrast, 56 (88%) of the 64 patients without pneumonia did not. CONCLUSION: The results of this study indicate the following: a) nonbronchoscopic PSB and BAL were feasible in a large population of mechanically ventilated children; b) nonbronchoscopic techniques were contributive for diagnosing ventilator-associated pneumonia in children; and c) a combined diagnostic approach, using nonbronchoscopic PSB and BAL, was superior to using either test alone.

Bacteria↗

Magnetic resonance imaging of the fetus.

Fetal magnetic resonance imaging (FMRI) has gained considerable interest during the last decade, especially in its intracranial applications. Due to its high soft-tissue contrast and presumed safety, FMRI should be accepted as a complementary technique in prenatal diagnosis, useful either to elucidate equivocal findings on routine US studies or to further delineate some pathological entities. Normal patterns of fetal brain maturation, as shown by FMRI, are described because they are of paramount importance to accurately evaluate intracranial diseases. To date, however, FMRI requires specialised facilities and should be considered as an evolving clinical research modality and performed within precise guidelines in a multidisciplinary approach to prenatal pathology.

Brain↗

[Prenatal MRI of corpus callosum agenesis. Study of 20 cases with neuropathological correlations].

Twenty prenatal MR studies of corpus callosum agenesis were retrospectively studied and compared with neuropathologic examinations (18) or postnatal imaging (2). Corpus callosum agenesis were either complete (14) or partial (6). Positive diagnosis was made in 19 cases/20. The diagnosis of "isolated" or "associated" corpus callosum agenesis was assessed in 11 cases/15. MR depicted 15 of the 33 associated neurologic abnormalities. Prenatal MR is a valuable complementary technique for the diagnosis of corpus callosum agenesis when sonography is doubtful. MR could improve prognosis evaluation, since it enables depiction of associated abnormalities, notably gyral abnormalities, posterior fossa malformations, and intra-cranial cysts. MR images prove to be useful before neuropathologic examinations.

Agenesis of Corpus Callosum↗

Dynamic gadolinium-enhanced subtraction MR imaging--a simple technique for the early diagnosis of Legg-Calvé-Perthes disease: preliminary results.

PURPOSE: To determine whether the simple technique of dynamic gadolinium-enhanced subtraction MR imaging, which is available on standard MR units, can detect ischemia of the femoral head in children with early Legg-Calvé-Perthes disease (LCP). MATERIALS AND METHODS: Bone perfusion of eight hips in four patients (mean age 7.5 years) was studied using dynamic gadolinium-enhanced subtraction MR imaging at the onset of proven LCP (with initial negative plain films). Enhancement of subtracted images was compared with that on standard MR images and with bone scintigraphy findings. RESULTS: Subtraction MR imaging depicted ischemia as a widespread absence of enhancement and was in good agreement with bone scintigraphy. The subtraction technique improved the sensitivity and the specificity of MR imaging in two children. Furthermore, subtraction MR imaging allowed recognition of the pattern of early reperfusion. CONCLUSION: Our preliminary results indicate that dynamic gadolinium-enhanced subtraction MRI is a simple and promising means of early recognition of ischemia in LCP.

Child↗

[Doppler ultrasonography in the study of the vascularization of the femur head in newborn infants].

PURPOSE: To establish the effectiveness of color Doppler and power Doppler ultrasound (US) in identifying the arterial supply of the femoral head in newborn. MATERIAL AND METHODS: Sixty normal hips in 30 newborns (mean age: 22 days) were imaged with a 7 MHz transducer. The presence and Doppler characteristics of flow in the branches of the inferior and superior arterial groups were documented according to the anatomic description of Lagrange and Dunoyer. RESULTS: The arterial flow within the chondroepiphysis from the inferior and superior branches was visualized in 100% and 91% cases, respectively. The transversal trochanter major incidence was the most adequate. Abduction without stress did not induce modification of the arterial supply. CONCLUSION: Visualization of femoral head vascularity with Power Doppler and color Doppler US is feasible and consistent in the majority of healthy neonates.

Arteries↗