Children with biliary atresia are prone to developing progressive hepatic fibrosis and biliary ci... more Children with biliary atresia are prone to developing progressive hepatic fibrosis and biliary cirrhosis following the Kasai operation. The only treatment is liver transplantation. To assess liver fibrosis by acoustic radiation force impulse elastography (ARFI) in children who had Kasai operation, with the goal of identifying an ARFI value cut-off for children requiring liver transplantation. Of the 32 post-Kasai children included, 19 were transplanted or listed for transplantation (group A), while 13 were not on the list during their follow-up (group B). We recorded biopsies, blood samples and ARFI values over time, including at Kasai operation and at transplantation. We estimated an association between groups and continuous variables using generalized estimating equations, and we compared categorical variables using the Fisher exact test. Portal hypertension signs were similar in both groups, whereas ARFI values were higher in group A (mean±standard deviation=3.3±1.2 m/s) than in group B (2.0±0.7 m/s; P=.0003). Eighteen of 19 (94.7%) children in group A and 6/13 (46.2%) children in group B presented with two consecutive ARFI values ≥2 m/s (sensitivity=7%, specificity=53.8%; P=0.003). We found that children who were transplanted had two consecutive ARFI values ≥2 m/s during follow-up. ARFI for evaluation of post-Kasai liver fibrosis may assist the long-term assessment of biliary atresia and may even guide treatment decisions.
Although the orbit is a small anatomical space, the wide range of structures present within it ar... more Although the orbit is a small anatomical space, the wide range of structures present within it are often the site of origin of various tumours and tumour-like conditions, both in adults and children. Cross-sectional imaging is mandatory for the detection, characterization, and mapping of these lesions. This review focuses on multiparametric imaging of orbital tumours. Each tumour is reviewed in relation to its clinical presentation, compartmental location, imaging characteristics, and its histological features. We herein describe orbital tumours as lesions of the globe (retinoblastoma, uveal melanoma), optic nerve sheath complex (meningioma, optic nerve glioma), conal-intraconal compartment (hemangioma), extraconal compartment (dermoid/epidermoid, lacrimal gland tumours, lymphoma, rhabdomysarcoma), and bone and sinus compartment (fibrous dysplasia). Lesions without any typical compartmental localization and those with multi-compartment involvement (veno-lymphatic malformation, plexiform neurofibroma, idiopathic orbital pseudotumour, IgG4 related disease, metastases) are also reviewed. We discuss the role of advanced imaging techniques, such as MR diffusion-weighted imaging (DWI), diffusion tensor imaging, fluoro-2-deoxy-D-glucose positron emission tomography CT (FDG-PET CT), and positron emission tomography MRI (MRI PET) as problem-solving tools in the evaluation of those orbital masses that present with non-specific morphologic imaging findings. Main messages/Teaching points • A compartment-based approach is essential for the diagnosis of orbital tumours. • CT and MRI play a key role in the work-up of orbital tumours. • DWI, PET CT, and MRI PET are complementary tools to solve diagnostic dilemmas. • Awareness of salient imaging pearls and diagnostic pitfalls avoids interpretation errors.
PURPOSE/AIM Provide an overview of the technology and principles of lung MRI in pediatric patient... more PURPOSE/AIM Provide an overview of the technology and principles of lung MRI in pediatric patients. Illustrate potential clinical indications and applications of chest MRI through imaging examples. Compare the utility of chest MRI with radiographs, ultrasound and MDCT CONTENT ORGANIZATION This exhibit will be structured to present the following: 1- Review acquisition protocols and procedural considerations for chest MR studies in infants and children 2- Present a systematic overview of the indications (cystic fibrosis, follow-up of lung infections, congenital malformations and masses) 3- Compare MRI with other radiological modalities (radiographs, ultrasound and MDCT) SUMMARY Among the modalities for lung imaging, MRI has been the latest to be introduced into clinical practice. MR is increasingly being used for evaluating the chest in pediatric patients given its lack of ionizing radiation, the high contrast resolution and good morphological information. Chest MRI may be considered ...
Whole-body MRI (WBMRI) is a non-irradiating imaging technique, suitable to investigate the extent... more Whole-body MRI (WBMRI) is a non-irradiating imaging technique, suitable to investigate the extent of multisystemic diseases in pediatric patients. However its real impact on diagnosis and management of non-oncological pediatric diseases remains unclear. We present our experience of pediatric WBMRI in various pathologies. We retrospectively reviewed medical files of all non- oncologic patients who underwent WBMRI from January 2008 to November 2012. The MRI protocol included T1 weighted and 3D SPACE Inversion Recovery (IR) and fat saturated diffusion weighted (DWI) sequence. We reviewed medical records in order to determine if performing WBMRI added useful information for diagnostic purposes and/or changed clinical management. Forty-two children were included in the study (19 F, 23 M) (median age 4.7 years). Twenty-one children underwent general anesthesia. WBMRI was a useful tool to provide correct diagnosis in chronic recurrent multifocal osteomyelitis (CRMO), and to identify the or...
The invention relates to a multi-cylinder Otto cycle internal combustion engine for motor vehicle... more The invention relates to a multi-cylinder Otto cycle internal combustion engine for motor vehicles, of the type in which the number of working cylinders varies with the power delivered, and in which the working cylinders for any power condition have a compression ratio which is greater than the compression ratio of the complementary cylinders, these latter being supercharged.
European Journal of Pediatric Surgery Reports, 2015
Zinner syndrome, the association of congenital seminal vesicle cyst and ipsilateral renal agenesi... more Zinner syndrome, the association of congenital seminal vesicle cyst and ipsilateral renal agenesis, is more often reported in adults or older adolescents. We present a case of a boy, followed up in our hospital since birth for right renal agenesis who at the age of 4 years presented a right paravesical cyst on ultrasound. The cyst was initially considered as an ureterocele. The diagnosis of Zinner syndrome was made later, at the age of 15 years by ultrasound and magnetic resonance imaging; at that moment the cyst had increased in size and had changed in aspect. This malformation should be considered in the differential diagnosis of a pelvic cyst in male patients with renal agenesis.
In many cell types, septins assemble into filaments and rings at the neck of cellular appendages ... more In many cell types, septins assemble into filaments and rings at the neck of cellular appendages and/or at the cleavage furrow to help compartmentalize the plasma membrane and support cytokinesis. How septin ring assembly is coordinated with membrane remodeling and controlled by mechanical stress at these sites is unclear. Through a genetic screen, we uncovered an unanticipated link between the conserved Rho1 GTPase and its effector protein kinase C (Pkc1) with septin ring stability in yeast. Both Rho1 and Pkc1 stabilize the septin ring, at least partly through phosphorylation of the membrane-associated F-BAR protein Syp1, which colocalizes asymmetrically with the septin ring at the bud neck. Syp1 is displaced from the bud neck upon Pkc1-dependent phosphorylation at two serines, thereby affecting the rigidity of the new-forming septin ring. We propose that Rho1 and Pkc1 coordinate septin ring assembly with membrane and cell wall remodeling partly by controlling Syp1 residence at the bud neck.
PURPOSE/AIM 1) To illustrate the role of imaging in the assessment of congenital and acquired non... more PURPOSE/AIM 1) To illustrate the role of imaging in the assessment of congenital and acquired non-tumoral pathology of pediatric female pelvis. 2) To present an interactive tool to navigate through different datasets in order to become familiar with common and unusual clinical cases imaged by different imaging modalities (US, CT, MRI). CONTENT ORGANIZATION - Normal US appearance of female pelvic organs at different ages - Pathological cases sorted in chapters regrouping different clinical categories: - ambiguous genitalia - US evaluation of prepubertal bleeding - precocious puberty - amenorrhea (primary and secondary, with and without pelvic pain) - pelvic pain (functional and hemorrhagic cysts, ovarian torsion, ovarian hernia, pelvic venous congestion, endometriosis) - tubal pathology (congenital tubal anomalies, hy SUMMARY 1) US appearance of normal pelvic organs at different ages for the assessment hormonal status. 2) congenital gynecological anomalies recognizable postnatally th...
The assessment of acute vertigo in childhood is often challenging, but fortunately a central caus... more The assessment of acute vertigo in childhood is often challenging, but fortunately a central cause is rarely identified. We present the case of a 7-year-old boy who developed, after a mild head trauma, a rotary vertigo associated with nausea and vomiting. A posttraumatic peripheral vestibular dysfunction was first suspected but not confirmed by an otoneurological evaluation. When subtle neurological signs were elicited, a brain magnetic resonance imaging was promptly requested. This showed a small infarct on the lateral posterior left part of the medulla oblongata of the brainstem, typical of Wallenberg syndrome. Vascular imaging was normal and no defined etiology was found. The child was started on prophylactic acetylsalicylic acid. The rapid disappearance of vertigo was noted. On follow-up at 6 months, there has been no recurrence and neurological examination was fully normal. Our case extends the differential diagnosis of acute vertigo in childhood that rarely includes the possibility of a brainstem infarct whose recognition through appropriate clinical examination is nevertheless capital for appropriate investigations and management.
Children with biliary atresia rapidly develop liver fibrosis secondary to inflammatory destructio... more Children with biliary atresia rapidly develop liver fibrosis secondary to inflammatory destruction of the biliary tract. Noninvasive detection of liver fibrosis in neonatal/infantile cholestasis is an additional criterion for the diagnosis of biliary atresia, leading to prompt surgical exploration. To assess the value of US with acoustic radiation force impulse (ARFI) elastography to detect biliary atresia in the workup of neonatal/infantile cholestasis. In this retrospective study, 20 children with cholestasis suspected of having biliary atresia were investigated by US and ARFI. We evaluated the association between US findings and the diagnosis of biliary atresia and with two scores of liver fibrosis obtained from liver biopsy. In univariate analyses, gallbladder size, triangular cord sign, spleen size and ARFI values were found to be associated with biliary atresia, though only the triangular cord sign remained significant when elevated gamma glutamyltransferase (GGT) was included as a predictor. In contrast, spleen size and ARFI correlated with the degree of liver fibrosis on biopsy (r > 0.70, P < 0.001), which remained significant when gamma glutamyltransferase elevation was included as a predictor. The addition of ARFI to a standard abdominal US in the initial workup of the neonate with possible infantile cholestasis can provide reliable information on liver fibrosis and help in the diagnosis of biliary atresia.
This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which... more This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods. The technical requirements and how they may help to understand, classify, or follow-up neurological pathologies are briefly summarized. Techniques, principles, advantages but also intrinsic limitations, typical artifacts, and alternative solutions developed to overcome them are discussed. In this article, we also review routinely available three-dimensional ...
The surgical correction of spinal deformities carries a small but significant risk of injury to t... more The surgical correction of spinal deformities carries a small but significant risk of injury to the spinal cord. To detect the onset and possibly reverse the effects of surgical complication, a variety of neurophysiological monitoring procedures can be employed. The purpose of this review is to provide information regarding the various methodologies available for monitoring spinal cord and nerve root function during orthopaedic procedures. Intra-operative monitoring of cortically recorded somatosensory evoked potentials (SEPs) by peripheral nerve stimulation is of value during orthopaedic surgery and is the state-of-the-art in terms of non-invasiveness, versatility, time requirement, lateral discrimination, and ease of electrode placement. Monitoring of motor evoked potentials (MEPs) is useful particularly in combination with SEPs but is still considered investigational. Root function monitoring has limited application and requires more clinical research.
Children with biliary atresia are prone to developing progressive hepatic fibrosis and biliary ci... more Children with biliary atresia are prone to developing progressive hepatic fibrosis and biliary cirrhosis following the Kasai operation. The only treatment is liver transplantation. To assess liver fibrosis by acoustic radiation force impulse elastography (ARFI) in children who had Kasai operation, with the goal of identifying an ARFI value cut-off for children requiring liver transplantation. Of the 32 post-Kasai children included, 19 were transplanted or listed for transplantation (group A), while 13 were not on the list during their follow-up (group B). We recorded biopsies, blood samples and ARFI values over time, including at Kasai operation and at transplantation. We estimated an association between groups and continuous variables using generalized estimating equations, and we compared categorical variables using the Fisher exact test. Portal hypertension signs were similar in both groups, whereas ARFI values were higher in group A (mean±standard deviation=3.3±1.2 m/s) than in group B (2.0±0.7 m/s; P=.0003). Eighteen of 19 (94.7%) children in group A and 6/13 (46.2%) children in group B presented with two consecutive ARFI values ≥2 m/s (sensitivity=7%, specificity=53.8%; P=0.003). We found that children who were transplanted had two consecutive ARFI values ≥2 m/s during follow-up. ARFI for evaluation of post-Kasai liver fibrosis may assist the long-term assessment of biliary atresia and may even guide treatment decisions.
Although the orbit is a small anatomical space, the wide range of structures present within it ar... more Although the orbit is a small anatomical space, the wide range of structures present within it are often the site of origin of various tumours and tumour-like conditions, both in adults and children. Cross-sectional imaging is mandatory for the detection, characterization, and mapping of these lesions. This review focuses on multiparametric imaging of orbital tumours. Each tumour is reviewed in relation to its clinical presentation, compartmental location, imaging characteristics, and its histological features. We herein describe orbital tumours as lesions of the globe (retinoblastoma, uveal melanoma), optic nerve sheath complex (meningioma, optic nerve glioma), conal-intraconal compartment (hemangioma), extraconal compartment (dermoid/epidermoid, lacrimal gland tumours, lymphoma, rhabdomysarcoma), and bone and sinus compartment (fibrous dysplasia). Lesions without any typical compartmental localization and those with multi-compartment involvement (veno-lymphatic malformation, plexiform neurofibroma, idiopathic orbital pseudotumour, IgG4 related disease, metastases) are also reviewed. We discuss the role of advanced imaging techniques, such as MR diffusion-weighted imaging (DWI), diffusion tensor imaging, fluoro-2-deoxy-D-glucose positron emission tomography CT (FDG-PET CT), and positron emission tomography MRI (MRI PET) as problem-solving tools in the evaluation of those orbital masses that present with non-specific morphologic imaging findings. Main messages/Teaching points • A compartment-based approach is essential for the diagnosis of orbital tumours. • CT and MRI play a key role in the work-up of orbital tumours. • DWI, PET CT, and MRI PET are complementary tools to solve diagnostic dilemmas. • Awareness of salient imaging pearls and diagnostic pitfalls avoids interpretation errors.
PURPOSE/AIM Provide an overview of the technology and principles of lung MRI in pediatric patient... more PURPOSE/AIM Provide an overview of the technology and principles of lung MRI in pediatric patients. Illustrate potential clinical indications and applications of chest MRI through imaging examples. Compare the utility of chest MRI with radiographs, ultrasound and MDCT CONTENT ORGANIZATION This exhibit will be structured to present the following: 1- Review acquisition protocols and procedural considerations for chest MR studies in infants and children 2- Present a systematic overview of the indications (cystic fibrosis, follow-up of lung infections, congenital malformations and masses) 3- Compare MRI with other radiological modalities (radiographs, ultrasound and MDCT) SUMMARY Among the modalities for lung imaging, MRI has been the latest to be introduced into clinical practice. MR is increasingly being used for evaluating the chest in pediatric patients given its lack of ionizing radiation, the high contrast resolution and good morphological information. Chest MRI may be considered ...
Whole-body MRI (WBMRI) is a non-irradiating imaging technique, suitable to investigate the extent... more Whole-body MRI (WBMRI) is a non-irradiating imaging technique, suitable to investigate the extent of multisystemic diseases in pediatric patients. However its real impact on diagnosis and management of non-oncological pediatric diseases remains unclear. We present our experience of pediatric WBMRI in various pathologies. We retrospectively reviewed medical files of all non- oncologic patients who underwent WBMRI from January 2008 to November 2012. The MRI protocol included T1 weighted and 3D SPACE Inversion Recovery (IR) and fat saturated diffusion weighted (DWI) sequence. We reviewed medical records in order to determine if performing WBMRI added useful information for diagnostic purposes and/or changed clinical management. Forty-two children were included in the study (19 F, 23 M) (median age 4.7 years). Twenty-one children underwent general anesthesia. WBMRI was a useful tool to provide correct diagnosis in chronic recurrent multifocal osteomyelitis (CRMO), and to identify the or...
The invention relates to a multi-cylinder Otto cycle internal combustion engine for motor vehicle... more The invention relates to a multi-cylinder Otto cycle internal combustion engine for motor vehicles, of the type in which the number of working cylinders varies with the power delivered, and in which the working cylinders for any power condition have a compression ratio which is greater than the compression ratio of the complementary cylinders, these latter being supercharged.
European Journal of Pediatric Surgery Reports, 2015
Zinner syndrome, the association of congenital seminal vesicle cyst and ipsilateral renal agenesi... more Zinner syndrome, the association of congenital seminal vesicle cyst and ipsilateral renal agenesis, is more often reported in adults or older adolescents. We present a case of a boy, followed up in our hospital since birth for right renal agenesis who at the age of 4 years presented a right paravesical cyst on ultrasound. The cyst was initially considered as an ureterocele. The diagnosis of Zinner syndrome was made later, at the age of 15 years by ultrasound and magnetic resonance imaging; at that moment the cyst had increased in size and had changed in aspect. This malformation should be considered in the differential diagnosis of a pelvic cyst in male patients with renal agenesis.
In many cell types, septins assemble into filaments and rings at the neck of cellular appendages ... more In many cell types, septins assemble into filaments and rings at the neck of cellular appendages and/or at the cleavage furrow to help compartmentalize the plasma membrane and support cytokinesis. How septin ring assembly is coordinated with membrane remodeling and controlled by mechanical stress at these sites is unclear. Through a genetic screen, we uncovered an unanticipated link between the conserved Rho1 GTPase and its effector protein kinase C (Pkc1) with septin ring stability in yeast. Both Rho1 and Pkc1 stabilize the septin ring, at least partly through phosphorylation of the membrane-associated F-BAR protein Syp1, which colocalizes asymmetrically with the septin ring at the bud neck. Syp1 is displaced from the bud neck upon Pkc1-dependent phosphorylation at two serines, thereby affecting the rigidity of the new-forming septin ring. We propose that Rho1 and Pkc1 coordinate septin ring assembly with membrane and cell wall remodeling partly by controlling Syp1 residence at the bud neck.
PURPOSE/AIM 1) To illustrate the role of imaging in the assessment of congenital and acquired non... more PURPOSE/AIM 1) To illustrate the role of imaging in the assessment of congenital and acquired non-tumoral pathology of pediatric female pelvis. 2) To present an interactive tool to navigate through different datasets in order to become familiar with common and unusual clinical cases imaged by different imaging modalities (US, CT, MRI). CONTENT ORGANIZATION - Normal US appearance of female pelvic organs at different ages - Pathological cases sorted in chapters regrouping different clinical categories: - ambiguous genitalia - US evaluation of prepubertal bleeding - precocious puberty - amenorrhea (primary and secondary, with and without pelvic pain) - pelvic pain (functional and hemorrhagic cysts, ovarian torsion, ovarian hernia, pelvic venous congestion, endometriosis) - tubal pathology (congenital tubal anomalies, hy SUMMARY 1) US appearance of normal pelvic organs at different ages for the assessment hormonal status. 2) congenital gynecological anomalies recognizable postnatally th...
The assessment of acute vertigo in childhood is often challenging, but fortunately a central caus... more The assessment of acute vertigo in childhood is often challenging, but fortunately a central cause is rarely identified. We present the case of a 7-year-old boy who developed, after a mild head trauma, a rotary vertigo associated with nausea and vomiting. A posttraumatic peripheral vestibular dysfunction was first suspected but not confirmed by an otoneurological evaluation. When subtle neurological signs were elicited, a brain magnetic resonance imaging was promptly requested. This showed a small infarct on the lateral posterior left part of the medulla oblongata of the brainstem, typical of Wallenberg syndrome. Vascular imaging was normal and no defined etiology was found. The child was started on prophylactic acetylsalicylic acid. The rapid disappearance of vertigo was noted. On follow-up at 6 months, there has been no recurrence and neurological examination was fully normal. Our case extends the differential diagnosis of acute vertigo in childhood that rarely includes the possibility of a brainstem infarct whose recognition through appropriate clinical examination is nevertheless capital for appropriate investigations and management.
Children with biliary atresia rapidly develop liver fibrosis secondary to inflammatory destructio... more Children with biliary atresia rapidly develop liver fibrosis secondary to inflammatory destruction of the biliary tract. Noninvasive detection of liver fibrosis in neonatal/infantile cholestasis is an additional criterion for the diagnosis of biliary atresia, leading to prompt surgical exploration. To assess the value of US with acoustic radiation force impulse (ARFI) elastography to detect biliary atresia in the workup of neonatal/infantile cholestasis. In this retrospective study, 20 children with cholestasis suspected of having biliary atresia were investigated by US and ARFI. We evaluated the association between US findings and the diagnosis of biliary atresia and with two scores of liver fibrosis obtained from liver biopsy. In univariate analyses, gallbladder size, triangular cord sign, spleen size and ARFI values were found to be associated with biliary atresia, though only the triangular cord sign remained significant when elevated gamma glutamyltransferase (GGT) was included as a predictor. In contrast, spleen size and ARFI correlated with the degree of liver fibrosis on biopsy (r > 0.70, P < 0.001), which remained significant when gamma glutamyltransferase elevation was included as a predictor. The addition of ARFI to a standard abdominal US in the initial workup of the neonate with possible infantile cholestasis can provide reliable information on liver fibrosis and help in the diagnosis of biliary atresia.
This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which... more This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods. The technical requirements and how they may help to understand, classify, or follow-up neurological pathologies are briefly summarized. Techniques, principles, advantages but also intrinsic limitations, typical artifacts, and alternative solutions developed to overcome them are discussed. In this article, we also review routinely available three-dimensional ...
The surgical correction of spinal deformities carries a small but significant risk of injury to t... more The surgical correction of spinal deformities carries a small but significant risk of injury to the spinal cord. To detect the onset and possibly reverse the effects of surgical complication, a variety of neurophysiological monitoring procedures can be employed. The purpose of this review is to provide information regarding the various methodologies available for monitoring spinal cord and nerve root function during orthopaedic procedures. Intra-operative monitoring of cortically recorded somatosensory evoked potentials (SEPs) by peripheral nerve stimulation is of value during orthopaedic surgery and is the state-of-the-art in terms of non-invasiveness, versatility, time requirement, lateral discrimination, and ease of electrode placement. Monitoring of motor evoked potentials (MEPs) is useful particularly in combination with SEPs but is still considered investigational. Root function monitoring has limited application and requires more clinical research.
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Papers by Laura Merlini