Diagnostic Brain Imaging Research Articles

Magnetic resonance imaging acquisition techniques intended to decrease movement artefact in paediatric brain imaging: a systematic review.

Attaining paediatric brain images of diagnostic quality can be difficult because of young age or neurological impairment. The use of anaesthesia to reduce movement in MRI increases clinical risk and cost, while CT, though faster, exposes children to potentially harmful ionising radiation. MRI acquisition techniques that aim to decrease movement artefact may allow diagnostic paediatric brain imaging without sedation or anaesthesia. We conducted a systematic review to establish the evidence base for ultra-fast sequences and sequences using oversampling of k-space in paediatric brain MR imaging. Techniques were assessed for imaging time, occurrence of movement artefact, the need for sedation, and either image quality or diagnostic accuracy. We identified 24 relevant studies. We found that ultra-fast techniques had shorter imaging acquisition times compared to standard MRI. Techniques using oversampling of k-space required equal or longer imaging times than standard MRI. Both ultra-fast sequences and those using oversampling of k-space reduced movement artefact compared with standard MRI in unsedated children. Assessment of overall diagnostic accuracy was difficult because of the heterogeneous patient populations, imaging indications, and reporting methods of the studies. In children with shunt-treated hydrocephalus there is evidence that ultra-fast MRI is sufficient for the assessment of ventricular size.

Metabolic evaluation of children with global developmental delay.

Global developmental delay (GDD) is a relatively common early-onset chronic neurological condition, which may have prenatal, perinatal, postnatal, or undetermined causes. Family history, physical and neurological examinations, and detailed history of environmental risk factors might suggest a specific disease. However, diagnostic laboratory tests, brain imaging, and other evidence-based evaluations are necessary in most cases to elucidate the causes. Diagnosis of GDD has recently improved because of remarkable advances in genetic technology, but this is an exhaustive and expensive evaluation that may not lead to therapeutic benefits in the majority of GDD patients. Inborn metabolic errors are one of the main targets for the treatment of GDD, although only a small proportion of GDD patients have this type of error. Nevertheless, diagnosis is often challenging because the phenotypes of many genetic or metabolic diseases often overlap, and their clinical spectra are much broader than currently known. Appropriate and cost-effective strategies including up-to-date information for the early identification of the "treatable" causes of GDD are needed for the development of well-timed therapeutic applications with the potential to improve neurodevelopmental outcomes.

Advisory Group Draws Roadmap for President’s BRAIN Initiative

Back to table of contents Previous article Next article Clinical and Research NewsFull AccessAdvisory Group Draws Roadmap for President’s BRAIN InitiativeAaron LevinAaron LevinSearch for more papers by this authorPublished Online:9 Oct 2013https://doi.org/10.1176/appi.pn.2013.10b14AbstractAn interim report for President Obama’s BRAIN Initiative focuses on new technologies to develop an integrated view of brain circuits and their function.President Obama’s Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Working Group should focus on intermediate circuits and activity in the brain—those more complex than individual cells but not yet encompassing the whole brain, said an interim advisory report presented September 16 at the National Institutes of Health (NIH).“Our goal is to look at the broad impact of this project on neuroscience research by posing problems, not dictating solutions,” said committee cochair William Newsome, Ph.D., a professor at Stanford University, in a teleconference.“The challenge is to map the circuits of the brain, measure the fluctuating patterns of electrical and chemical activity flowing within those circuits, and understand how their interplay creates our unique cognitive and behavioral capabilities,” said the committee’s written report. “[O]ur ultimate goal is to understand our own brains.”The advisory committee included one psychiatrist, Karl Deisseroth, M.D., Ph.D., a professor of bioengineering and of psychiatry and behavioral sciences at Stanford University.The committee heard from dozens of invited experts representing a variety of relevant fields: chemistry, molecular biology, electrophysiology, optics, structural neurobiology, data analysis, computation, and human neuroscience.“The focus is not on technology per se, but on the development and use of tools for acquiring fundamental insight about how the nervous system functions in health and disease,” the report stressed.Once under way, the program should begin by generating a census of neuronal and glial cell types and creating structural maps of the brain, said cochair Cornelia Bargmann, Ph.D., a professor at Rockefeller University in New York.Work would begin first with animal models, graduating eventually to humans. But human research data could come even now from patients undergoing diagnostic brain imaging or by monitoring those receiving deep brain stimulation and other technological interventions.“We’re seeking an understanding of the dynamics of the brain: where signals come from and how they are related to internal states,” said Newsome.Understanding brain circuits will mean identifying and characterizing their cells, clarifying synaptic connections, observing patterns of activity during behavior, and perturbing these patterns to assess their significance, said the report. Doing so will mean integrating observations of the brain in action across time and space. Such research will require new or improved technologies to record brain activity, manipulate brain circuits, and then connect neuronal activity to behavior in the organism. That research and the tools to process the immense quantities of data require close collaboration between neuroscientists and computer specialists, statisticians, physicists, engineers, and other scientists.Rapid dissemination of these tools as they are developed, through training modules and summer courses, would accelerate progress.The BRAIN Initiative will need sustained support over many years, says NIH Director Francis Collins, M.D., Ph.D.National Institutes of Health “The overarching vision is to combine these approaches into a single, integrated science of cells, circuits, brain, and behavior,” said the report.The committee will present its final report in June 2014.What will happen then is an open question given the current confusion over federal budgets.“It’s hard to be specific, but this project will need sustained support over many years,” said NIH Director Francis Collins, M.D., Ph.D. “We will need to nail down a timeline in June.” ■The advisory committee’s report is posted at http://www.nih.gov/science/brain/09162013-Interim%20Report_Final%20Composite.pdf. ISSUES NewArchived

Diagnostic Brain Imaging in Psychiatry: Current Uses and Future Prospects

Diagnostic Brain Imaging in Psychiatry: Current Uses and Future Prospects

Developing a Diagnostic Brain Imaging Protocol for Recent Onset Psychosis which Embodies Principles of Predictive Coding and Free Energy

Although schizophrenia is usually conceptualized of as a disorder of well formed hallucinations and delusions, its onset is more typically characterized by heightened arousal, a vague but pervasive feeling of unease and poorly formed misperceptions. This unstable constellation of symptoms challenges clinical diagnosis at a time when properly guided interventions are most likely to have the greatest long-term benefits. It is possible to frame this clinical picture as a disturbance in the capacity of the cortex to optimally form predictive models of the environment, to appropriately sample visual scenes in order to estimate the likelihood of such models and to hence minimize surprise in a dynamic social landscape. This approach suggests that manipulating the relationship between visual search strategies and natural scene statistics might be a sensitive means of quantifying core neurobiological deficits early in the course of emerging psychotic disorders. We are developing a diagnostic tool for the prodromal phase of these disorders which involves experimentally disturbing the relationship between visual saccades and the stream of natural images in well directed films. I will outline the conceptual and computational bases and early experimental results thus far obtained, including a canonical example of paranoia and theory of mind in a spaghetti western.

Functional Neuroimaging to Characterize Visual System Development in Children with Retinoblastoma

To use functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to investigate visual system development in children being treated for retinoblastoma. Informed consent was obtained for all participants (N = 42) in this institutional review board-approved study. Participants were imaged with a 1.5-T scanner while under propofol sedation. Diagnostic brain and orbital imaging was followed by investigational functional neuroimaging, which included fMRI during photic stimulation through closed eyelids, to measure functional activation in the visual cortex, and DTI, to evaluate diffusion parameters of white matter tracts in the corpus callosum and the periventricular optic radiations. Analysis included 115 examinations of 39 patients with a median age of 16.4 months and age range from 1.5 to 101.5 months at first evaluation. The blood oxygen level-dependent signal was predominantly negative and located in the anterior visual cortex. Activation was affected by tumor lateralization (unilateral or bilateral), macular involvement, and retinal detachment. Patients who had undergone unilateral enucleation showed cortical dominance corresponding to the projection from the nasal hemiretina in the unaffected eye. Diffusion parameters followed a normal developmental trajectory in the optic radiations and corpus callosum, but variability was greater in the splenium than in the genu of the corpus callosum. Longitudinal functional neuroimaging demonstrated important effects of disease and treatment. Therefore, fMRI and DTI may be useful for characterizing the impact of retinoblastoma on the developing visual system and improving the prediction of visual outcome in survivors.

An audit assessing the incidence, prevalence and quality of management of neurocognitive disorders in 88 HIV positive children

AimsAn audit was carried out to assess the prevalence of neurocognitive disorders (NCDs) in 88 HIV positive children. This audit also recorded the Cerebrospinal fluid Penetration Effectiveness (CPE) score of...

Development of memory clinics in the Netherlands: 1998 to 2009

Objectives: Memory clinics (MCs) are multidisciplinary teams involved with early diagnosis and treatment of people with dementia. The main aim of this study was to gain more insight into the development of MCs in the Netherlands since 1998. Methods: In 1998, 2004 and 2009, an MC survey with questions about patient groups, organisation and working procedures of the MC were sent to all MCs in the Netherlands. Results: The number of MCs increased from 12 in 1998, to 43 in 2004 and to 63 in 2009. In 2009, MCs were better embedded with other regional care and were delivering services for dementia with less emphasis on university-based research. While dementia was still the most common syndromal diagnosis, the proportion of subjects diagnosed with milder memory problems increased to 39%. Diagnostic tools, blood assessments and brain imaging were used in nearly all the facilities. There was an increase both in the use of extensive neuropsychological assessments and in the use of cerebrospinal fluid diagnostics. Conclusion: MCs in the Netherlands have outgrown the primarily university-based setting, have focussed less on scientific research, and have taken a place in the regular care of people with cognitive problems and people in early phases of dementia.

Ictal but Not Interictal Epileptic Discharges Activate Astrocyte Endfeet and Elicit Cerebral Arteriole Responses

Activation of astrocytes by neuronal signals plays a central role in the control of neuronal activity-dependent blood flow changes in the normal brain. The cellular pathways that mediate neurovascular coupling in the epileptic brain remain, however, poorly defined. In a cortical slice model of epilepsy, we found that the ictal, seizure-like discharge, and only to a minor extent the interictal discharge, evokes both a Ca2+ increase in astrocyte endfeet and a vasomotor response. We also observed that rapid ictal discharge-induced arteriole responses were regularly preceded by Ca2+ elevations in endfeet and were abolished by pharmacological inhibition of Ca2+ signals in these astrocyte processes. Under these latter conditions, arterioles exhibited after the ictal discharge only slowly developing vasodilations. The poor efficacy of interictal discharges, compared with ictal discharges, to activate endfeet was confirmed also in the intact in vitro isolated guinea pig brain. Although the possibility of a direct contribution of neurons, in particular in the late response of cerebral blood vessels to epileptic discharges, should be taken into account, our study supports the view that astrocytes are central for neurovascular coupling also in the epileptic brain. The massive endfeet Ca2+ elevations evoked by ictal discharges and the poor response to interictal events represent new information potentially relevant to interpret data from diagnostic brain imaging techniques, such as functional magnetic resonance, utilized in the clinic to localize neural activity and to optimize neurosurgery of untreatable epilepsies.

Demographic, Maltreatment, and Neurobiological Correlates of PTSD Symptoms in Children and Adolescents

To examine the relationships of demographic, maltreatment, neurostructural and neuropsychological measures with total posttraumatic stress disorder (PTSD) symptoms. Participants included 216 children with maltreatment histories (N = 49), maltreatment and PTSD (N = 49), or no maltreatment (N = 118). Participants received diagnostic interviews, brain imaging, and neuropsychological evaluations. We examined a hierarchical regression model comprised of independent variables including demographics, trauma and maltreatment-related variables, and hippocampal volumes and neuropsychological measures to model PTSD symptoms. Important independent contributors to this model were SES, and General Maltreatment and Sexual Abuse Factors. Although hippocampal volumes were not significant, Visual Memory was a significant contributor to this model. Similar to adult PTSD, pediatric PTSD symptoms are associated with lower Visual Memory performance. It is an important correlate of PTSD beyond established predictors of PTSD symptoms. These results support models of developmental traumatology and suggest that treatments which enhance visual memory may decrease symptoms of PTSD.

Predictors of ischemic stroke after hip operation: a population-based study.

Hip operation (total hip arthroplasty [THA] or fracture repair) is the most common noncardiac surgical procedure performed in patients age 65 years and older. To determine the predictors of ischemic stroke in patients who have undergone hip operation. Population-based historical cohort study, in which postoperative ischemic strokes were identified from medical record review for stroke diagnostic codes and brain imaging results and were confirmed by physician review. Tertiary care center in Olmsted County, Minnesota. Residents of Olmsted County who underwent hip surgical procedure. Incidence of ischemic stroke within 1 year of hip operation. In total, 1606 patients underwent 1886 hip procedures from 1988 through 2002 and were observed for ischemic stroke for 1 year after their procedure. Sixty-seven ischemic strokes were identified. The rate of stroke at 1 year after hip operation was 3.9%. In univariate analysis, history of atrial fibrillation (hazard ratio [HR], 2.16; P = 0.005), hip fracture repair vs. total hip arthroplasty (HR, 3.80; P < 0.001), age 75 years or older (HR, 2.20; P = 0.02), aspirin use (HR, 1.8; P = 0.01), and history of previous stroke (HR, 4.18; P < 0.001) were significantly associated with increased risk of stroke. In multivariable analysis, history of stroke (HR, 3.27; P < 0.001) and hip fracture repair (HR, 2.74; P = 0.004) were strong predictors of postoperative stroke. This population-based historical cohort of patients with hip operation had a 3.9% cumulative probability of ischemic stroke over the first postoperative year. Hip fracture repair and history of stroke were the strongest predictors of this complication.

Are There Inequalities in the Provision of Stroke Care?

There is evidence of unequal access to health care interventions even where universal health systems operate. We investigated associations between patients' sociodemographic characteristics and the provision of acute and longer-term stroke care in a multiethnic urban population. We used data from 1635 patients with first-ever stroke, collected by a population-based stroke register from 1995 to 2000. Using multivariable analyses, controlled for sociodemographic and clinical factors, we investigated access to 22 evidence-based components of care. 1392 patients (85.1%) were admitted to hospital; of these, 354 (25.4%) were admitted or transferred to a stroke unit. Of those with clinical need, 607 (70.7%) received physical therapies; 477 (59.8%) received speech and language therapy. Older age was associated with lower odds of hospitalization (odds ratio [OR], 0.50; 95% CI, 0.32 to 0.77, P=0.02) and diagnostic brain imaging (OR, 0.15; 95% CI, 0.08 to 0.30, P<0.01) but higher odds of receiving physical therapy (OR, 4.24; 95% CI, 1.22 to 14.73, P<0.01). Black ethnicity was associated with higher odds of stroke unit admission (OR, 1.59; 95% CI, 1.01 to 2.49, P<0.04). There was a weak association between socioeconomic status and admission to hospital and stroke unit. Gender was associated only with treatment of hypertension before stroke. Provision of individual components of care over 1 year varied for specific sociodemographic categories, but there was no consistent pattern of inequality. Clinical decision-making processes are likely to influence these patterns. Further information about clinician and patient roles in decision making is required.

Brain development in healthy, hyperactive, and psychotic children.

Serious and chronic childhood psychiatric disorders have long been assumed to reflect relatively subtle abnormalities of brain development. Although diagnostic brain imaging is well established in pediatric neurology, it has not yet permitted quantitative assessment of brain abnormalities in children with psychiatric illnesses. Recent advances in brain magnetic resonance imaging (MRI) allow reliable, automated, quantitative measurement of multiple brain regions. 1 The noninvasive nature of MRI also allows periodic rescanning for research purposes, making prospective longitudinal study of brain development feasible in large numbers of healthy children and those with psychiatric illness. 2,3 Longitudinal MRI of the brain also makes possible the mapping of region-specific changes in brain volume over time.

Application of gamma camera imaging and SPECT systems in chemical processes

SPECT imaging systems are used in nuclear medicine for diagnostic imaging of heart, brain, lung and other organ functions. Radio-pharmaceuticals are injected in the blood stream of a patient. The propagation of the radio-pharmaceutical is monitored as a function of position and time using a gamma camera. In many tests, the monitoring occurs in real time. This technique has been extended for use in chemical process monitoring in our laboratory. In particular, a Siemens gamma camera with SPECT capabilities is routinely used for real time tracer studies, radioactive particle tracking and SPECT imaging. The same radio-pharmaceuticals used in medical testing are used for process monitoring. The system has been used in determining hydrodynamic properties of gas/solid and liquid/solid fluidized beds and in visualizing and monitoring of multi-phase flow phenomena in porous media.

Cost management strategies for carotid endarterectomy

Background: We developed a model for capitation and global pricing for carotid endarterectomy. Methods: A care algorithm for diagnosis, perioperative management, and postoperative care using cost data was developed. Perioperative care charges were extrapolated from a 1-year experience and applied to models to determine pricing for a 1-year global fee and a 5-year capitated contract. Results: Global pricing was estimated at $12,071 per patient while a capitated price for 5-year care was $17,175. Based on the age mix of the population, a per member, per month cost could be calculated assuming a frequency of 414 procedures per 100,000 patients over age 65 and 31 procedures per 100,000 patients under 65. Sources of costs were extensive preoperative diagnostic testing, particularly angiography, brain imaging, and cardiac evaluation. Conclusions: Global pricing and capitation are both feasible for carotid endarterectomy. Each approach has unique risks and benefits.

Brain Imaging

Advances in medical technology have revolutionized diagnostic brain imaging. Traditional radiography and invasive contrast studies for intracranial imaging have been superseded by several newer imaging modalities which provide high resolution, crosssectional images. Ultrasonography, computed tomography, magnetic resonance, and nuclear scintigraphy are now used for anatomical and functional imaging of the brain. These noninvasive modalities are available at most veterinary teaching institutions and are offered through many larger referral practices. The diagnostic usefulness and clinical limitations for each of these modalities are described.

A rat model of herpes encephalitis with special reference to its potential for the development of diagnostic brain imaging

A rat model of herpes encephalitis using intraocular inoculation of herpes simplex virus strain SC16 was investigated. Virus distribution in the brain was examined by virus isolation and immunocytochemical staining using immuno-gold silver and peroxidase-anti-peroxidase. At 5 days post-infection virus was found in the thalamus, hypothalamus, septum, colliculus, geniculate bodies, the pons, trapezoidium and medulla oblongata, but less frequently, in the cerebellum and occipital lobes. Possible routes of spread of virus and the potential of this model in neuro-radiological scanning procedures are discussed.