Advanced magnetic resonance imaging techniques in perinatal brain injury

Despite marked improvements in perinatal practice, perinatal brain injury remains one of the most common complications causing chronic handicapping conditions. Experimental advances have elucidated many of the cellular and vascular mechanisms of perinatal brain damage showing a correlation between the nature of the injury and the maturation of the brain. New diagnostic tools, such as quantitative three-dimensional magnetic resonance (MR) imaging, diffusion-weighted MR imaging and proton MR spectroscopy, are presented in this review article that allow to assess brain development, detect early brain injury and monitor effects of perinatal brain injury on subsequent brain development and brain plasticity. These techniques will guide future therapeutic interventions aimed at minimizing irreversible perinatal brain injury.     

Immune thrombocytopenic purpura: Historical perspective, current status, recent advances and future directions

Immune thrombocytopenic purpura (ITP) has witnessed many changes and updates over the past decade. The definitions of disease subtypes, course and response to treatment have all been standardized recently. Consequent to the lack of an international consensus management guideline, wide variations exist in treatment practice. This is now being addressed to an extent by the much awaited ITP International Working Group 2010 recommendations. The pathophysiologic mechanisms have been unfolded at cellular, molecular and humoral levels. As a result, many recent advances have taken place in the management of this disorder. This review revisits the history of evolution of ITP, summarizes the current recommendations for management and lists the recent advances and future prospects in this field.     

Magnetic resonance imaging in perinatal brain injury: clinical presentation, lesions and outcome

Neonatal MR imaging is invaluable in assessing the term born neonate who presents with an encephalopathy. Successful imaging requires adaptations to both the hardware and the sequences used for adults. The perinatal and postnatal details often predict the pattern of lesions sustained and are essential for correct interpretation of the imaging findings, but additional or alternative diagnoses in infants with apparent hypoxic ischaemic encephalopathy should always be considered. Perinatally acquired lesions are usually at their most obvious between 1 and 2 weeks of age. Very early imaging (<3 days) may be useful to make management decisions in ventilated neonates, but abnormalities may be subtle at that stage. Diffusion-weighted imaging is clinically useful for the early identification of ischaemic white matter in the neonatal brain but is less reliable in detecting lesions within the basal ganglia and thalami. The pattern of lesions seen on MRI can predict neurodevelopmental outcome. Additional useful information may be obtained by advanced techniques such as MR angiography, venography and perfusion-weighted imaging. Serial imaging with quantification of both structure size and tissue damage provides invaluable insights into perinatal brain injury.     

Magnetic resonance imaging and proton magnetic resonance spectroscopy of the brain in the diagnostic evaluation of developmental delay

AimTo assess the contribution of MRI and proton spectroscopy (1HMRS) in establishing an etiological diagnosis in children with developmental delay (DD) and to assess whether the chance of finding specific abnormalities correlates with the presence of neurological signs and/or abnormal head circumference (HC).MethodsPatients were derived from a cohort of 325 consecutive patients with DD receiving structured multidisciplinary evaluation in our centre. Patients had MRI/1HMRS if a diagnosis could not be made clinically and if additional neurological signs and/or abnormal HC and/or an IQ below 50 were present. The MRI protocol consisted of axial IR, T2, FLAIR, sagittal T1 and coronal T2 sequences. Multivoxel 1HMRS was located in a plane superior to the lateral ventricles with voxels in both grey matter and white matter.ResultsOne hundred and nine children were scanned, 80 of them because of neurological signs and/or abnormal HC. Although minor abnormalities were noted in the vast majority of patients, MRI and/or 1HMRS really contributed to an etiological diagnosis in only 10 (9%) patients, all of whom were scanned because of neurological signs. In these 10 patients, 1HMRS was diagnostic in one patient and of additional value to MRI findings in 3 patients.ConclusionsMRI and 1HMRS may contribute to the diagnostic evaluation of DD, especially if applied specifically to patients with neurological signs, whereas its role is very limited in children without these signs.     

Magnetic resonance imaging of the brain in children with headache: the clinical relevance with modern acquisition techniques

The aim of this study was to evaluate the frequency of abnormal findings in magnetic resonance imaging (MRI) in children with headache, the clinical relevance of these findings, and whether more sophisticated technologies also result in more relevant abnormal findings. The MRIs of 1004 children with age ranging from 1 to 17 years were retrospectively analyzed. Children who were investigated with established sequences (n = 419) were compared with those examined with state-of-the-art MRI acquisition technology (n = 585). In 216/1004 investigations, MRI was performed because of headache (74/216 with established sequences, 142/216 with state-of-the-art acquisition technology). In 114/216 (52.8%) patients with headache, the MRI was abnormal with relevant findings in 23/114 patients and findings without clinical relevance in 91/114 children. A higher incidence of abnormal findings than in previous reports was found but there was only limited clinical gain of information using modern sequences in children with headache.     

Magnetic resonance imaging of the neonatal brain

Neonatal magnetic resonance (MR) imaging is rapidly becoming the preferred modality for the evaluation of central nervous system disorders in the newborn. Recent literature supports the value of this imaging technique in diagnosing ischemic, hemorrhagic and infectious disease processes in the premature and full-term neonatal brain. Recent data in premature newborns with neurological injury also suggest a role for MR imaging in determining long-term neurodevelopmental outcomes. This review article provides a framework and overview on neonatal MR imaging techniques and examines the literature or radiological disease patterns and prognostic implications in common neurological disorders.     

Advanced MR techniques in the term-born neonate with perinatal brain injury

Magnetic resonance imaging (MRI) has become an essential tool for assessing the neonatal brain. Conventional imaging can detect patterns of injury that relate to the aetiology and timing of an insult and provide valuable information about prognosis. Sequences must always be adapted for the immature brain. Diffusion techniques improve the detection of ischaemic tissue and allow more accurate timing of an insult. Diffusion tensor imaging allows the assessment of tissue microstructure changes with normal development as well as in response to tissue injury. Diffusion tractography will further our understanding of the long-term effects of perinatal injuries on brain development, and when used in combination with clinical and functional imaging studies will allow the plasticity of the immature brain to be studied. MR angiography and venography are important adjuncts to the clinical examination, and when combined with perfusion studies can provide valuable information about vessel development following injury. Detailed vascular studies may detect inherent susceptibilities, which give rise to lesions in some babies but not others. The future for neonatal imaging is exciting; however, detailed and serial imaging of carefully chosen cohorts of infants coupled with long-term clinical follow-up are essential to ensure the clinical significance of any new findings.     

Magnetic resonance imaging of the brain in newborn infants: Practical aspects

Magnetic Resonance Imaging is becoming more widely available and increasingly important for imaging the neonatal brain. In newborn infants it poses challenges regarding patient preparation, safety, optimal timing, and sequence optimization. These issues are addressed in this paper and indications for performing neonatal Magnetic Resonance Imaging are presented.     

Inflicted traumatic brain injury: advances in evaluation and collaborative diagnosis

The determination that a traumatic brain injury is not accidental requires data collection from multiple domains: historical, clinical, laboratory, radiographic, environmental and psychosocial. These essential, yet disparate, types of information must be synthesized in a collaborative and interdisciplinary process to formulate a medical opinion with regard to the cause of an injury, and the final opinion has tremendous consequences for children and families. Medically directed child protection teams have emerged as the standard of care in many children's hospitals and child abuse pediatrics is now a recognized medical subspecialty with board certification available in the next several years. Not only do the child and family benefit from this coordinated effort, but there are also great benefits for the members of the child protection team: more clearly defined responsibilities, redirected focus on treatment for the surgeon, and increased confidence that the opinion is based upon consensus and current scientific knowledge. By this process and its division of labor, the child abuse pediatrician assumes responsibility for ensuring that a final medical opinion is arrived at, and then advocates for appropriate disposition for the child. The child abuse pediatrician is responsible for establishing institutional standards for family evaluation, collecting all necessary medical data and directing a consensus-based decision making process that is based upon current medical knowledge, medical literature and experience. The child abuse pediatrician also assumes the role of primary communication conduit for investigational agencies and the courts. The neurosurgeon is a key member of the child protection team and relies on the team to obtain necessary historical information to address consistency of the mechanism with the sustained injuries and has an integral role in determining the team's final opinion. An interdisciplinary response to inflicted traumatic brain injury is the cornerstone for establishing a rigorous standard of care; it also fosters education across medical subspecialties where controversy has been a significant part of the landscape. Valid and useful clinical research that describes head injury as accidental or inflicted can only be performed in the context of an interdisciplinary, medically directed child protection team that strives for objectivity and precision in the determination of the manner of an injury.     

Magnetic resonance imaging of the brain in congenital cytomegalovirus infection

Ten children (age 2 months to 8 years) with a congenital cytomegalovirus (CMV) infection were studied by magnetic resonance imaging (MRI) using a 2.35 Tesla magnet. CMV infection was confirmed by serological investigations and virus culture in the neonatal period. Nine children had severe mental retardation and cerebral palsy, 1 patient suffered from microcephaly, ataxia and deafness. The cranial MRI examination showed the following abnormalities (N): dilated lateral ventricles (10) and subarachnoid space (8), oligo/pachygyria (8), delayed/pathological myelination (7), paraventricular cysts (6), intracerebral calcification (1). This lack of sensitivity for calcification is explainable by the basic principles of MRI. The paraventricular cystic lesions were adjacent to the occipital horns of the lateral ventricles and separated only by a thin membrane. This finding might represent a “new sign” for congenital CMV infection in MRI examinations, being characteristic but nevertheless nonspecific, like calcification in CT. Presented in part at the ESPR meeting in Montreux 1988.     

Magnetic resonance imaging of the brain in childhood herpesvirus infections

We used magnetic resonance imaging (MRI) to evaluate nine children with neurologic disorders caused by infections with members of the herpesvirus family. MRI studies were abnormal in eight children and demonstrated a wide range of central nervous system lesions, including cystic encephalomalacia, ventricular enlargement, cerebral atrophy and focal parenchymal lesions. When compared with conventional computed tomographic scanning, MRI was more sensitive in detecting abnormalities of white matter and in defining the extent of parenchymal lesions. These studies indicate that MRI scans are highly useful in children with herpesvirus infections involving the central nervous system.     

Magnetic resonance and ultrasound brain imaging in preterm infants

Cranial ultrasonography has been used to identify brain injury in preterm neonates for more than two decades. More recently, magnetic resonance imaging has been used to evaluate brain development and pathology in these infants. In this review we describe how well findings from these two imaging modalities agree with histology findings and neuro-developmental outcome. In addition, we discuss studies comparing ultrasound and magnetic resonance imaging findings.