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Determining the timing of intracranial injuries in general, and abusive head trauma (AHT) in particular, is important to the care of children with traumatic brain injury. Additionally, identifying the time of the injury provides important information as to who might have, and who did not, inflict the trauma. Understanding the appearance and evolution of intracranial findings on neuroimaging has been an important factor in assessing the time of the injury. However, a number of studies in the last two decades have both suggested greater uncertainty about the reliability of this process and advanced our knowledge in this area. In this review, the authors consider the biophysical factors that contribute to the appearance and evolution of intracranial hemorrhage and, in particular, subdural hemorrhage (SDH). The traditional view of SDH is predicated largely on prior studies of intracerebral hemorrhage, although a number of variables make this comparison untenable. Moreover, more recent studies have suggested a number of factors that could alter the density (CT) or signal intensity (MRI) and produce mixed density/intensity SDH. These factors need to be considered in interpreting neuroimaging studies. A number of these recent studies evaluating serial neuroimaging in children with AHT have modified our understanding of intracranial hemorrhage and its evolution in this context. Taken together, the studies to date, having important limitations, provide only broad ranges over which to time injuries. The authors conclude that neuroimaging studies at this time are not likely, in isolation, to be able to accurately pinpoint a specific time of injury; rather, neuroimaging can only provide a range of possible times and should instead be used as a means to supplement or corroborate timing based on clinical presentation and other imaging findings.

Abusive head trauma (AHT) is the leading cause of fatal head injuries in children younger than 2 years. A multidisciplinary team bases this diagnosis on history, physical examination, imaging and laboratory findings. Because the etiology of the injury is multifactorial (shaking, shaking and impact, impact, etc.) the current best and inclusive term is AHT. There is no controversy concerning the medical validity of the existence of AHT, with multiple components including subdural hematoma, intracranial and spinal changes, complex retinal hemorrhages, and rib and other fractures that are inconsistent with the provided mechanism of trauma. The workup must exclude medical diseases that can mimic AHT. However, the courtroom has become a forum for speculative theories that cannot be reconciled with generally accepted medical literature. There is no reliable medical evidence that the following processes are causative in the constellation of injuries of AHT: cerebral sinovenous thrombosis, hypoxic–ischemic injury, lumbar puncture or dysphagic choking/vomiting. There is no substantiation, at a time remote from birth, that an asymptomatic birth-related subdural hemorrhage can result in rebleeding and sudden collapse. Further, a diagnosis of AHT is a medical conclusion, not a legal determination of the intent of the perpetrator or a diagnosis of murder. We hope that this consensus document reduces confusion by recommending to judges and jurors the tools necessary to distinguish genuine evidence-based opinions of the relevant medical community from legal arguments or etiological speculations that are unwarranted by the clinical findings, medical evidence and evidence-based literature.

Background Spinal imaging has been a neglected part of abusive head trauma (AHT) imaging. As most of the radiographs and CT spine are negative in AHT in infants, the cervical spine is assumed to be normal. There is increasing evidence in the role of injury to brainstem and cervical cord in the pathogenesis of AHT. In addition, in courts of law, there is fierce debate about AHT, its mimics and other disparate nontraumatic diagnoses explaining the neuroradiological and skeletal findings. However, this discussion ignores the evidence and significance of spinal injury. We sought to study the cervical spine in an AHT cohort to understand the true prevalence of spinal injuries in AHT and contrast it with cohorts of accidental and nontraumatic groups to give the clinicians a robust diagnostic tool in evaluating AHT. Objective The purpose of this study is to compare the relative incidence of spinal ligamentous and soft-tissue abnormalities on spinal MRI among three groups of children ages <48 months: 1) those with AHT, 2) those with accidental trauma, and 3) those with nontraumatic conditions. Materials and methods This comparative study included 183 children who underwent spine MRI: 67 with AHT, 46 with accidental trauma and a clinical suspicion of spinal injury, and 70 with nontraumatic conditions. Clinical and radiographic findings were collected in all cases and were analyzed retrospectively to identify MRI evidence of traumatic spinal injuries. The incidence of spinal injuries among the three groups was compared. The incidence of spinal ligamentous injuries was calculated for those with and without radiographic evidence of hypoxic-ischemic encephalopathy. All comparisons were performed using Fisher exact test with P  < 0.05 considered statistically significant. Results Cervical spine ligamentous injuries (predominantly the nuchal, atlanto-occipital and atlanto-axial ligaments) were present in 78% of the AHT group, 46% of the accidental trauma group and 1% of the nontraumatic group; all of these differences were statistically significant. Among the AHT group, ligamentous injuries were statistically correlated with evidence of brain ischemia. Conclusion Injury to the cervical spinal posterior ligamentous complex is common in AHT and even more prevalent than in clinically symptomatic traumatic cases. The high correlation between the radiographic findings of occipitocervical ligamentous injuries and hypoxic-ischemic brain injury is consistent with an interpretation that transient upper occipitocervical spinal cord injury in AHT leads to disordered breathing and results in hypoxic-ischemic encephalopathy. We recommend imaging the entire spine in AHT to properly identify and classify these injuries.

BackgroundArterial blood sampling is the gold standard method to obtain the arterial input function (AIF) for quantification of whole body (WB) dynamic 18F-FDG PET imaging. However, this procedure is invasive and not typically available in clinical environments. As an alternative, we compared AIFs to population-based input functions (PBIFs) using two normalization methods: area under the curve (AUC) and extrapolated initial plasma concentration (CP*(0)). To scale the PBIFs, we tested two methods: (1) the AUC of the image-derived input function (IDIF) and (2) the estimated CP*(0). The aim of this study was to validate IDIF and PBIF for FDG oncological WB PET studies by comparing to the gold standard arterial blood sampling.MethodsThe Feng 18F-FDG plasma concentration model was applied to estimate AIF parameters (n = 23). AIF normalization used either AUC(0–60 min) or CP*(0), estimated from an exponential fit. CP*(0) is also described as the ratio of the injected dose (ID) to initial distribution volume (iDV). iDV was modeled using the subject height and weight, with coefficients that were estimated in 23 subjects. In 12 oncological patients, we computed IDIF (from the aorta) and PBIFs with scaling by the AUC of the IDIF from 4 time windows (15–45, 30–60, 45–75, 60–90 min) (PBIFAUC) and estimated CP*(0) (PBIFiDV). The IDIF and PBIFs were compared with the gold standard AIF, using AUC values and Patlak Ki values.ResultsThe IDIF underestimated the AIF at early times and overestimated it at later times. Thus, based on the AUC and Ki comparison, 30–60 min was the most accurate time window for PBIFAUC; later time windows for scaling underestimated Ki (− 6 ± 8 to − 13 ± 9%). Correlations of AUC between AIF and IDIF, PBIFAUC(30–60), and PBIFiDV were 0.91, 0.94, and 0.90, respectively. The bias of Ki was − 9 ± 10%, − 1 ± 8%, and 3 ± 9%, respectively.ConclusionsBoth PBIF scaling methods provided good mean performance with moderate variation. Improved performance can be obtained by refining IDIF methods and by evaluating PBIFs with test-retest data.

Abusive head trauma (AHT) is the most lethal form of child abuse; preventing AHT should be a national priority, but research into this area is woefully underfunded. Prevention programs have primarily focused on universal parent education during the neonatal period, a time when parents are a captive audience of the health care establishment whose focus is on the needs of their newborn infant, and who will soon be exposed to the frustration and anger of infant crying. Research has suggested a strong causal link between infant crying and AHT, and parents — particularly fathers and father figures — have been identified as the most common perpetrators of AHT. A number of studies have suggested that educating parents during the postnatal period about the normalcy of inconsolable infant crying and its evolution over the first several months of postnatal life improves parental knowledge about infant crying and a number of positive parenting behaviors, and decreases emergency room visits for crying. In 1998, we began a pilot program in Upstate New York near Buffalo that led to a 47% reduction in AHT incidence. Similar studies have demonstrated 35–75% reductions in incidence, which has led to enthusiasm for this approach to preventing AHT. We, as well as another group, have enacted statewide programs in Pennsylvania and North Carolina; unfortunately, these two large statewide replication trials failed to demonstrate any impact of such an intervention on AHT rates. Serial messages for parents, provided repeatedly over the period of greatest risk for AHT, might be another avenue of research.

BackgroundRetinal hemorrhages are one of the most important supportive evidences for abusive head trauma (AHT). Susceptibility-weighted imaging (SWI) is highly suited to identify various forms of intracranial hemorrhage in AHT. However its utility in imaging retinal hemorrhage is not well established.ObjectiveSWI is a sensitive sequence for identifying retinal hemorrhage on MRI.Materials and methodsIn this retrospective analysis, 26 consecutive infants and young children with a suspected admission diagnosis of AHT underwent indirect ophthalmoscopy and brain MRI protocol for AHT along with SWI. Brain susceptibility-weighted images of 14 age-matched children were used as controls. For detecting retinal hemorrhage, susceptibility-weighted images of patients and controls were reviewed randomly and independently by two neuroradiologists who were blinded to the history and ophthalmology findings. A pediatric ophthalmologist graded the indirect ophthalmoscopy images.ResultsA diagnosis of AHT was confirmed in all 26 cases from a multidisciplinary meeting. Indirect ophthalmoscopy images were available in 21 cases. Ophthalmoscopy was positive for retinal hemorrhage in the right eye in 18 cases (85.7%) and in the left eye in 16 cases (76.2%). On SWI, retinal hemorrhage was identified in the right eye in 9/21 cases (42.8%) and in the left eye in 8/21 cases (38.1%) of AHT. Analysis of SWI in 21 cases of AHT demonstrated a sensitivity of 50%, specificity of 100%, positive predictive value of 100% and negative predictive value of 32% for detecting retinal hemorrhage.ConclusionSWI is moderately sensitive and highly specific for identifying retinal hemorrhage in AHT. Further studies are needed to identify steps to improve the efficiency of SWI in detecting retinal hemorrhage.

Pediatric radiologists are frequently summoned to testify in court regarding the imaging of child abuse. This essay provides guidance on how to prepare for trial and what to expect in court. Preparation is paramount and includes meeting with the attorney and reviewing imaging studies, medical records and pertinent reports in anticipation of questioning in court. We also provide guidance to aid in testimony in court. Legal standards for testimony are discussed herein.

Background Abusive head trauma (AHT) is an important cause of serious brain injury in infants and young children who have characteristic clinical and imaging findings that are discordant with the clinical history provided. Recent attention has focused on abnormalities of the cranial venous sinuses and cortical veins, both on MRI and at autopsy. Although many have interpreted these to be secondary to the AHT, some have recently argued that these venous abnormalities represent primary cortical sinus and venous thrombosis that leads secondarily to subdural hemorrhage and secondary brain injury. Direct trauma to the veins and sinuses has been reported at autopsy in AHT, but there has been no systematic study of venous abnormalities in cases of AHT. Objective The purpose of this study was to define the incidence and characteristics of venous and sinus abnormalities in AHT. Materials and methods We included all children <36 months of age who were diagnosed with abusive head trauma between 2001 and 2012 and who had MRI and magnetic resonance (MR) venography as part of their diagnostic workup. We analyzed age, gender and clinical findings. MRI and MR venography were analyzed independently by two neuroradiologists with a focus on abnormalities involving the intracranial veins and venous sinuses. Results A total of 45 children were included. The median age was 3 months (range 15 days to 31 months) and 28 were boys (62%). Clinical findings included retinal hemorrhage in 71% and extracranial fractures in 55%. CT or MRI demonstrated subdural hemorrhage in 41 (91%); none had subdural effusions. In 31 cases (69%) MR venography demonstrated mass effect on the venous sinuses or cortical draining veins, with either displacement or partial or complete effacement of the venous structures from an adjacent subdural hematoma or brain swelling. We also describe the lollipop sign, which represents direct trauma to the cortical bridging veins and was present in 20/45 (44%) children. Conclusion Evidence of displacement or compression of cortical veins and sinuses from subdural hemorrhage or edema on MR venography was present in the majority of children with abusive head trauma. Evidence of direct trauma to the veins (lollipop sign) was identified in nearly half of cases. It is important to understand the superimposed effects of subdural hematoma and brain swelling on the veins and sinuses to differentiate it from cortical sinus and venous thrombosis.

Parkinson’s disease (PD) is the fastest growing neurodegenerative disease, but at present there is no cure, nor any disease-modifying treatments. Synaptic biomarkers from in vivo imaging have shown promise in imaging loss of synapses in PD and other neurodegenerative disorders. Here, we provide new clinical insights from a cross-sectional, high-resolution positron emission tomography (PET) study of 30 PD individuals and 30 age- and sex-matched healthy controls (HC) with the radiotracer [ 11 C]UCB-J, which binds to synaptic vesicle glycoprotein 2A (SV2A), and is therefore, a biomarker of synaptic density in the living brain. We also examined a measure of relative brain perfusion from the early part of the same PET scan. Our results provide evidence for synaptic density loss in the substantia nigra that had been previously reported, but also extend this to other early-Braak stage regions known to be affected in PD (brainstem, caudate, olfactory cortex). Importantly, we also found a direct association between synaptic density loss in the nigra and severity of symptoms in patients. A greater extent and wider distribution of synaptic density loss in PD patients with longer illness duration suggests that [ 11 C]UCB-J PET can be used to measure synapse loss with disease progression. We also demonstrate lower brain perfusion in PD vs. HC groups, with a greater extent of abnormalities in those with longer duration of illness, suggesting that [ 11 C]UCB-J PET can simultaneously provide information on changes in brain perfusion. These results implicate synaptic imaging as a useful PD biomarker for future disease-modifying interventions.