Neurometabolism and brain morphometry in an adolescent female with an extra-hepatic congenital portosystemic shunt.

Background: Chronic hepatic encephalopathy (CHE) has been reported both in patients with congenital porto-systemic shunts (CPSS) and chronic liver disease. CHE is difficult to recognize in children as there is no clear definition and its manifestations are highly variable. CHE is associated with variations in brain volumes and metabolites that have already been demonstrated using 1.5-3T MRI systems. However, the in-depth study of brain metabolism requires the high spectral resolution of high magnetic fields. Objectives and Methods: We analyzed the neurometabolic profile, brain volumes and T1 relaxation times of a child with a CPSS using high field proton magnetic resonance spectroscopy (1H MRS, 7T) combined with MRI and compared it to an age-matched control group. We also evaluated the impact of shunt closure on neurocognitive symptoms using adapted neuropsychological tests. Results: 7T MRS revealed a significant increase in glutamine compared to controls, a decrease in brain osmolytes, and a slight elevation in NAA concentrations. 7T MRI scans showed morphological abnormalities but no changes in the signal intensity of the globus pallidus. Neurocognitive testing revealed attention deficit disorder, language difficulties, and mild intellectual disability. Most of these areas improved after shunt closure. Conclusions: In this paediatric case of type B HE with normal fasting ammonia, neurometabolic profile was compatible with what has been previously shown in chronic liver disease, while also demonstrating an isolated glutamine peak. In addition, neurocognitive function partially improved after shunt closure, arguing strongly for shunt closure in both presymptomatic and symptomatic patients.

A forensic case of hydranencephaly in a preterm neonate fully documented by postmortem imaging techniques.

The authors present a medico-legal autopsy case of hydranencephaly in a male preterm newborn, fully documented by postmortem unenhanced and enhanced imaging techniques (postmortem computed tomography and postmortem magnetic resonance imaging). Hydranencephaly is a congenital anomaly of the central nervous system, consisting in almost complete absence of the cerebral hemispheres and replacement of the cerebral parenchyma by cerebrospinal fluid, rarely encountered in forensic medical practice. A premature baby was born during the supposed 22nd and 24th week of pregnancy in the context of a denial of pregnancy without any follow-up. The newborn died a few hours after birth and medico-legal investigations were requested to determine the cause of death and exclude the intervention of a third person in the lethal process. The external examination revealed neither traumatic nor malformative lesions. Postmortem imaging investigations were typical of hydranencephaly, and conventional medico-legal autopsy, neuropathological examination, and histological examination confirmed a massive necrotic-haemorrhagic hydranencephaly. This case represents in itself an association of out-of-the-ordinary elements making it worthy of interest. Key Points: Postmortem unenhanced and enhanced imaging techniques (computed tomography and magnetic resonance imaging) were performed as complementary examination to conventional medico-legal investigations.Postmortem angiography of a preterm newborn is possible with catheterization of the umbilical blood vessels.Hydranencephaly is a congenital anomaly of the central nervous system, consisting in almost complete absence of the cerebral hemispheres and replacement of the brain by cerebrospinal fluid, for which several aetiologies have been postulated.

High field brain proton magnetic resonance spectroscopy and volumetry in children with chronic, compensated liver disease - A pilot study.

BACKGROUND: There is increasing evidence that children or young adults having acquired liver disease in childhood display neurocognitive impairment which may become more apparent as they grow older. The molecular, cellular and morphological underpinnings of this clinical problem are incompletely understood. AIM: Therefore, we used the advantages of highly-resolved proton magnetic resonance spectroscopy at ultra-high magnetic field to analyze the neurometabolic profile and brain morphometry of children with chronic, compensated liver disease, hypothesizing that with high field spectroscopy we would identify early evidence of rising brain glutamine and decreased myoinositol, such as has been described both in animals and humans with more significant liver disease. METHODS: Patients (n = 5) and age-matched controls (n = 19) underwent 7T MR scans and short echo time 1H MR spectra were acquired using the semi-adiabatic SPECIAL sequence in two voxels located in gray and white matter dominated prefrontal cortex, respectively. A 3D MP2RAGE sequence was also acquired for brain volumetry and T1 mapping. Liver disease had to have developed at least 6 months before entering the study. Subjects underwent routine blood analysis and neurocognitive testing using validated methods within 3 months of MRI and MRS. RESULTS: Five children aged 8-16 years with liver disease acquired in childhood were included. Baseline biological characteristics were similar among patients. There were no statistically significant differences between subjects and controls in brain metabolite levels or brain volumetry. Finally, there were minor neurocognitive fluctuations including attention deficit in one child, but none fell in the statistically significant range. CONCLUSION: Children with chronic, compensated liver disease did not display an abnormal neurometabolic profile, neurocognitive abnormalities, or signal intensity changes in the globus pallidus. Despite the absence of neurometabolic changes, it is an opportunity to emphasize that it is only by developing the use of 1H MRS at high field in the clinical arena that we will understand the significance and generalizability of these findings in children with CLD. Healthy children displayed neurometabolic regional differences as previously reported in adult subjects.

Prenatal magnetic resonance imaging of complex female genitourinary system abnormalities, what the fetal medicine specialist needs to know.

Complex female genitourinary system anomalies include a wide spectrum of uncommon pathologies, caused from the abnormal separation of the urorectal septum and the urogenital sinus in early embryonic life. The resulting fusion of the distal urinary, genital and intestinal tracts increases the risk of death in utero and alters the normal organ functionality and the quality of life in survivors. An accurate prenatal identification of these pathologies depends mainly on prior suspicion at ultrasound screening, but also requires a solid knowledge of embryology and familiarity with the different patterns of malformation. Prenatal MRI provides an excellent anatomic evaluation of the fetal anatomy that may improve the diagnosis in complex cases with inconclusive echographic findings. The additional information can help both families and medical teams to better evaluate the severity of the pathology and the postnatal prognosis and therefore to better orientate the management during pregnancy, at delivery and after birth. This review article describes the embryological basis and the clinical findings of the most relevant pathologies included in the spectrum. It also describes the imaging signs on prenatal MRI studies in a series of confirmed cases and proposes a diagnostic algorithm based on imaging findings for guiding prenatal diagnosis.

A tailored passive driver for liver MRE in pediatric patients.

Objectives: Magnetic resonance elastography (MRE) is increasingly used in the pediatric population for diagnosis and staging of liver fibrosis. However, the MR-compatible driver and sequences are usually those used for adult patients. Our feasibility study aimed to adapt the standardized adult MRE passive driver and vibrational parameters to a pediatric population. Methods: We designed an elliptic passive driver shaped on a torus equipped with an elastic membrane and adapted to children's morphologies. As a first step, eight children (aged 8-18 years) were enrolled in a prospective pilot study aiming to determine the threshold vibrational amplitude for MRE using a custom passive driver, based on phase aliasing assessment and the occurrence of signal void artifacts on magnitude MR images. In the second step, the practicality and the consistency of the custom driver were assessed in a further 11 pediatric patients (aged 7-18 years). In the third step, we compared our custom driver vs. the commercial driver on six adult volunteers, in terms of the reliable region of interest area within the acquired MRE slices, the shear wave maps' quality, and measured stiffness values obtained. Results: Based on pediatric patient data, the threshold vibrational amplitude expressed as percentage of maximum output was found to be 0.4 and 1.1 times the body weight (kg) at 40 and 60 Hz frequencies, respectively. In comparison to the commercial passive driver, the custom driver improved threefold the contact with the body surface, also enabling a more comfortable examination as self-assessed by the volunteers. Conclusions: Our custom driver was more comfortable for the volunteers and was able to generate more homogenous shear waves, yielding larger usable hepatic area, and more reliable stiffness values.

Benefits of diffusion-weighted imaging in pediatric acute osteoarticular infections.

BACKGROUND: Contrast-enhanced magnetic resonance imaging (MRI) is recommended for the diagnosis of acute osteoarticular infections in children. Diffusion-weighted imaging (DWI) may be an alternative to the injection of gadolinium. OBJECTIVE: To evaluate unenhanced MRI with DWI in comparison to contrast-enhanced MRI for the diagnostic work-up of acute osteoarticular infections in children. MATERIALS AND METHODS: This retrospective study included 36 children (age range: 7 months-12 years) with extra-spinal osteoarticular infections and MRI performed within 24 h of admission. MRI protocol included short tau inversion recovery (STIR), water-only T2 Dixon, T1, DWI, and gadolinium-enhanced T1 sequences. Two readers reviewed three sets of images: 1) unenhanced sequences, 2) unenhanced sequences with DWI and 3) unenhanced followed by contrast-enhanced sequences (reference standard). Sensitivity and specificity of sets 1 and 2 were compared to set 3 and assessed to identify osteoarticular infections: osteomyelitis (long bones, metaphyseal equivalents), septic arthritis and abscess (soft tissues, bone). RESULTS: All 14 cases of osteomyelitis in the metaphyses and diaphyses of long bones and all 27 cases of septic arthritis were identified by unenhanced sequences, but 4/16 abscesses were missed. For the diagnosis of abscess, DWI increased sensitivity to 100%. Among the 18 osteomyelitis in metaphyseal equivalents, 4 femoral head chondroepiphyses were identified by contrast-enhanced sequences only. CONCLUSION: MRI for suspected pediatric acute osteoarticular infections is the best diagnostic modality to guide patient management. An unenhanced protocol with DWI may be an alternative to a contrast-based protocol, even in the presence of an abscess. However, gadolinium remains necessary to assess for chondroepiphyseal involvement of the femoral head.

A clinical and MRI retrospective cohort study of patients with juvenile idiopathic arthritis (JIA) to determine if initial temporomandibular joint (TMJ) examination findings are associated with severity of TMJ arthritis.

The purpose of the present study was to evaluate the association between initial TMJ examination findings and clinical and MRI severity of TMJ arthritis in a cohort of patients with JIA. The clinical variables were signs and symptoms at the initial TMJ evaluation. Outcome was the severity of TMJ arthritis as evaluated clinically by the Helkimo clinical dysfunction indices and by MRI. Associations of signs and symptoms with clinical and MRI severity were analyzed using a Fisher exact test and linear regression. The sample was composed of 101 patients with a mean age of 12.8 years, 76% of which were girls. Subjective difficulty in opening the mouth wide and objective limited MIO were the only clinical findings associated with both the severity of clinical dysfunction (p = 0.001 and p < 0.001, respectively) and the acute (p = 0.008 and p = 0.001, respectively) and chronic (p = 0.006 and p = 0.001, respectively) MRI severity of the TMJ arthritis. The results of this study suggest that in patients with JIA, limited mouth opening at the initial TMJ assessment may be a valid indicator of clinical severity of TMJ arthritis, which correlates with severity as seen on MRI.

Early arterial pressure monitoring and term-equivalent age MRI findings in very preterm infants.

INTRODUCTION: Variability of arterial blood pressure (ABP) has been associated with intraventricular hemorrhage in very preterm neonates (VPT) and may predict other brain lesions assessed at term-equivalent of age (TEA). METHODS: This was a prospective single-center study including VPT with early invasive continuous ABP monitoring and assessed at TEA using brain magnetic resonance imaging (TEA-MRI). The association between early mean ABP (MABP) and TEA-MRI findings was modeled by multivariate logistic regression analysis using covariates selected by the LASSO method. RESULTS: Among 99 VPT, the LASSO procedure selected consecutive periods of lowest MABP of 30 min on day 1 (d1) and 10 min on day 2 (d2) as the most relevant durations to predict TEA-MRI findings (OR [95% CI], 1.11 [1.02-1.23], p = 0.03 and 1.13 [1.01-1.27], p = 0.03, respectively). ROC curve analysis showed optimal thresholds at 30.25 mmHg on d1 and 33.25 mmHg on d2. This significant association persisted after adjustment with covariates including birthweight, gestational age, sex, and inotrope exposure. Final models selected by LASSO included the decile of the birthweight and lowest MABP for 30 min on d1 and 10 min on d2, for which the areas under the ROC curve were 74% and 75%, respectively. CONCLUSION: Early continuous ABP monitoring may predict brain TEA-MRI findings in VPT. IMPACT: Early arterial blood pressure monitoring may contribute to predicting brain damage upon MRI at term-equivalent of age for infants born very preterm. Careful blood pressure continuous monitoring in very preterm infants may identify infants at risk of long-term brain damage. Umbilical artery catheterization provides the best option for continuously monitoring arterial blood pressure in very preterm infants.

Acoustic radiation force impulse imaging: normal values of spleen stiffness in healthy children.

BACKGROUND: Acoustic radiation force impulse (ARFI) imaging is a noninvasive ultrasound elastography technique for evaluating tissue stiffness. The association of liver and spleen stiffness provides additional information in the assessment of portal hypertension. The technique and normal values of spleen stiffness by point shear wave elastography (p-SWE) in pediatrics have not been well documented. OBJECTIVE: Our aim is to describe the feasibility and normal ARFI elastography values in the spleen for healthy children and to compare measurements in two different probe positions (the axial and sagittal planes). MATERIALS AND METHODS: Spleen p-SWE using ARFI values were measured with a 6C1 probe in 102 healthy children (age range: 8 weeks to 17 years) divided into four age groups. An average of nine (standard deviation: two) spleen stiffness measurements were taken during free breathing in each plane (axial and sagittal). The impact of age and measurement plane in the spleen was analyzed using multivariate models. RESULTS: There was no significant difference in spleen stiffness values taken at different ages, with an average of the medians of 2.43±0.31 m/s. There was no significant difference based on probe orientation: sagittal plane (median: 2.46±0.29 m/s) and axial plane (median: 2.43±0.32 m/s) with Student's t-test P=0.18. The mean depth of measurement varied between 2.3 cm and 3.7 cm, according to age. CONCLUSION: Normal spleen stiffness values using ARFI imaging in children do not vary with age and correspond to a median of 2.43 m/s. No significant difference was found when using different probe positions.

Contribution of magnetic resonance imaging to the prenatal diagnosis of common congenital vascular anomalies.

BACKGROUND: Screening ultrasound (US) has increased the detection of congenital vascular anomalies in utero. Complementary magnetic resonance imaging (MRI) may improve the diagnosis, but its real utility is still not well established. OBJECTIVES: We aimed to describe the imaging findings on prenatal US and MRI of the most frequent congenital vascular anomalies (lymphatic malformations and congenital hemangiomas) to assess the accuracy of prenatal US and MRI exams for diagnosis and to evaluate the relevance of the additional information obtained by complementary fetal MRI. MATERIALS AND METHODS: All confirmed postnatal congenital vascular anomalies detected in the last 10 years at 3 university hospitals were retrospectively identified. The prenatal diagnosis was compared with the final diagnosis for both methods and the clinical relevance of additional MRI information was evaluated. A second MRI in advanced pregnancy was performed in fetuses with lesions in a sensitive anatomical location and the clinical relevance of the additional information was evaluated. RESULTS: Twenty-four cases were included in the study, 20 lymphatic malformations and 4 hemangiomas. MRI slightly improved the diagnosis of lymphatic malformation, 85% vs. 80% at US, especially for abdominal lesions. Both methods had a low identification rate (25%) for tumors. MRI performed late in five fetuses with lymphatic malformation allowed optimized management at birth. CONCLUSION: MRI improves the diagnosis of congenital lymphatic malformations whereas hemangiomas remain difficult to identify in utero. The main role of MRI is to provide high-defined anatomical data to guide management at birth.

De Novo KAT5 Variants Cause a Syndrome with Recognizable Facial Dysmorphisms, Cerebellar Atrophy, Sleep Disturbance, and Epilepsy.

KAT5 encodes an essential lysine acetyltransferase, previously called TIP60, which is involved in regulating gene expression, DNA repair, chromatin remodeling, apoptosis, and cell proliferation; but it remains unclear whether variants in this gene cause a genetic disease. Here, we study three individuals with heterozygous de novo missense variants in KAT5 that affect normally invariant residues, with one at the chromodomain (p.Arg53His) and two at or near the acetyl-CoA binding site (p.Cys369Ser and p.Ser413Ala). All three individuals have cerebral malformations, seizures, global developmental delay or intellectual disability, and severe sleep disturbance. Progressive cerebellar atrophy was also noted. Histone acetylation assays with purified variant KAT5 demonstrated that the variants decrease or abolish the ability of the resulting NuA4/TIP60 multi-subunit complexes to acetylate the histone H4 tail in chromatin. Transcriptomic analysis in affected individual fibroblasts showed deregulation of multiple genes that control development. Moreover, there was also upregulated expression of PER1 (a key gene involved in circadian control) in agreement with sleep anomalies in all of the individuals. In conclusion, dominant missense KAT5 variants cause histone acetylation deficiency with transcriptional dysregulation of multiples genes, thereby leading to a neurodevelopmental syndrome with sleep disturbance, cerebellar atrophy, and facial dysmorphisms, and suggesting a recognizable syndrome.

Management of delivery of a fetus with autosomal recessive polycystic kidney disease: a case report of abdominal dystocia and review of the literature.

BACKGROUND: Autosomal recessive renal polycystic kidney disease occurs in 1 in 20,000 live births. It is caused by mutations in both alleles of the PKHD1 gene. Management of delivery in cases of suspected autosomal recessive renal polycystic kidney disease is rarely discussed, and literature concerning abdominal dystocia is extremely scarce. We present a case of a patient with autosomal recessive renal polycystic kidney disease whose delivery was complicated by abdominal dystocia, and we discuss the factors that determined the route and timing of delivery. CASE PRESENTATION: A 23-year-old Caucasian woman, G2 P0, with a prior unremarkable pregnancy was referred to our tertiary center at 31 weeks of gestation because of severe oligoamnios (amniotic fluid index = 2) and hyperechogenic, dedifferentiated, and enlarged fetal kidneys. She had no other genitourinary anomaly. Fetal magnetic resonance imaging showed enlarged, hypersignal kidneys and severe pulmonary hypoplasia. We had a high suspicion of autosomal recessive renal polycystic kidney disease, and after discussion with our multidisciplinary team, the parents opted for conservative care. Ultrasound performed at 35 weeks of gestation showed a fetal estimated weight of 3550 g and an abdominal circumference of 377 mm, both above the 90th percentile. Because of the very rapid kidney growth and suspected risk of abdominal dystocia, we proposed induction of labor at 36 weeks of gestation after corticosteroid administration for fetal lung maturation. Vaginal delivery was complicated by abdominal dystocia, which resolved by continuing expulsive efforts and gentle fetal traction. A 3300-g (P50-90) male infant was born with Apgar scores of 1-7-7 at 1, 5, and 10 minutes, respectively, and arterial and venous umbilical cord pH values of 7.23-7.33. Continuous peritoneal dialysis was started at day 2 of life because of anuria. Currently, the infant is 1 year old and is waiting for kidney transplant that should be performed once he reaches 10 kg. Molecular analysis of PKHD1 performed on deoxyribonucleic acid (DNA) from the umbilical cord confirmed autosomal recessive renal polycystic kidney disease. CONCLUSIONS: Management of delivery in cases of suspected autosomal recessive renal polycystic kidney disease needs to be discussed because of the risk of abdominal dystocia. The route and timing of delivery depend on the size of the fetal abdominal circumference and the gestational age. The rate of kidney growth must also be taken into account.

Iterative algorithms for metal artifact reduction in children with orthopedic prostheses: preliminary results.

BACKGROUND: Increased computational power allows computed tomography (CT) software to process very advanced mathematical algorithms to generate better quality images at lower doses. One such algorithm, iterative metal artifact reduction (iMAR) has proven to decrease metal artifacts seen in CT images of adults with orthopedic implants. OBJECTIVES: To evaluate artifact reduction capability of the algorithm in lower-dose pediatric CT compared to our routine third-generation advanced modeled iterative reconstruction (ADMIRE) algorithm. MATERIALS AND METHODS: Thirteen children (11-17 years old) with metal implants underwent routine clinically indicated CT. Data sets were reconstructed with an iMAR algorithm. Hounsfield units and image noise were measured in bone, muscle and fat in the streak artifact (near the implant) and at the greatest distance from the artifact (far from the implant). A regression model compared the effects of the algorithm (standard ADMIRE vs. iMAR) near and far from the implant. RESULTS: Near the implant, Hounsfield units with iMAR were significantly different in our standard ADMIRE vs. iMAR for bone, muscle and fat (P<0.001). Noise was significantly different in standard ADMIRE vs. iMAR in bone (P<0.003). Far from the implant, Hounsfield units and noise were not significantly different for ADMIRE vs. iMAR, for the three tissue types. CONCLUSION: These preliminary results demonstrate that iMAR algorithms improves Hounsfield units near the implant and decreases image noise in bone in low-dose pediatric CT. It does this without changing baseline tissue density or noise far from the implant.

Benefit of Temporomandibular Joint Lavage With Intra-Articular Steroids Versus Lavage Alone in the Management of Temporomandibular Joint Involvement in Juvenile Idiopathic Arthritis.

PURPOSE: The aim of the present investigation was to evaluate, in patients with juvenile idiopathic arthritis, the effect of lavage with or without intra-articular corticosteroid (IACS) injection on clinical temporomandibular joint (TMJ) signs and symptoms of inflammation and changes in acute inflammation as assessed using magnetic resonance imaging (MRI). MATERIALS AND METHODS: Forty-one patients (mean age, 13.6 ± 4.0 yr) with juvenile idiopathic arthritis participating in a large prospective juvenile inflammatory rheumatism cohort study (JIRcohorte) were included in this study. Clinical history, examination, and MRI were carried out at baseline and 6 months after intervention, if any. Twenty-one patients underwent lavage and IACS injection in at least 1 TMJ, 8 patients underwent lavage of at least 1 TMJ, and 12 patients were followed with no intervention. Outcomes measured were maximal mouth opening, Helkimo dysfunction index scores, pain intensity, and acute inflammation as assessed using MRI. RESULTS: All groups showed a mean increase in mouth opening and mean decrease in pain intensity. The mean Helkimo clinical dysfunction score decreased for the 2 intervention groups but not for the control group. The mean Helkimo anamnestic dysfunction score decreased for the lavage with IACS group but not for the lavage-only group. The only statistically relevant difference was found for the Helkimo anamnestic dysfunction score comparing the lavage-only with the lavage with IACS group, with a more positive effect found in the lavage with IACS group. More than 50% of joints in each group showed no change at MRI examination. Joints with lavage and ICAS injection showed better improvement than joints that had lavage only or no intervention. CONCLUSION: TMJ lavage with or without IACS injection cannot be claimed to systematically decrease pain, increase mouth opening, or resolve acute inflammation. Despite a tendency for improvement, response to this treatment is very patient dependent and can be determined by an array of other variables.

Biallelic variants in LINGO1 are associated with autosomal recessive intellectual disability, microcephaly, speech and motor delay.

PURPOSE: To elucidate the novel molecular cause in two unrelated consanguineous families with autosomal recessive intellectual disability. METHODS: A combination of homozygosity mapping and exome sequencing was used to locate the plausible genetic defect in family F162, while only exome sequencing was followed in the family PKMR65. The protein 3D structure was visualized with the University of California-San Francisco Chimera software. RESULTS: All five patients from both families presented with severe intellectual disability, aggressive behavior, and speech and motor delay. Four of the five patients had microcephaly. We identified homozygous missense variants in LINGO1, p.(Arg290His) in family F162 and p.(Tyr288Cys) in family PKMR65. Both variants were predicted to be pathogenic, and segregated with the phenotype in the respective families. Molecular modeling of LINGO1 suggests that both variants interfere with the glycosylation of the protein. CONCLUSION: LINGO1 is a transmembrane receptor, predominantly found in the central nervous system. Published loss-of-function studies in mouse and zebrafish have established a crucial role of LINGO1 in normal neuronal development and central nervous system myelination by negatively regulating oligodendrocyte differentiation and neuronal survival. Taken together, our results indicate that biallelic LINGO1 missense variants cause autosomal recessive intellectual disability in humans.

Tracheal agenesis: optimization of computed tomography diagnosis by airway ventilation.

Tracheal agenesis is a rare and often lethal congenital defect that leads to airway emergency at birth. Computed tomography (CT) is the modality of choice to evaluate anomalous tracheal anatomy. The absence of spontaneous aeration of the tracheobronchial tree in children with tracheal agenesis makes CT interpretation difficult. We describe a procedure of airway management applied in two newborns with suspected tracheal agenesis. Correct airway management was performed immediately prior to CT examination by airway ventilation, with bag-valve mask alone in one case, and attached to an endotracheal tube placed into the esophagus in the other case. The images allowed for classification of tracheal agenesis. Computed tomography with appropriate airway ventilation is fundamental for the diagnosis of tracheal agenesis.

Diagnostic accuracy of MR imaging for direct visualization of lumbar pars defect in children and young adults: a systematic review and meta-analysis.

PURPOSE: The accurate diagnosis of spondylolysis is widely made with CT scan considered as the gold standard. However, CT represents significant radiation exposure particularly substantial in a young and sometimes still growing population. Although the role of MRI in identifying edema/inflammation within the pars as an active lesion is proved, its ability to demonstrate and classify pars fracture line as same as CT is still controversial. This meta-analysis aimed to determine sensitivity and specificity of MRI in the direct visualisation of the pars defect. METHODS: The PubMed and Embase databases were systematically searched for relevant studies from the earliest researchable time to December 2016 for cases in which the accuracy of MRI was reported for the diagnosis of spondylolysis in young patients. Two reviewers independently assessed the methodological quality for each selected study using the quality assessment of diagnostic accuracy studies 2 tool. A meta-analysis of the reported sensitivity and specificity of pooled data of selected studies was performed by a systematic review. For each selected study, sensitivity and specificity was recalculated, by considering only direct visualisation of a fracture line of the pars. The hierarchic summary receiver operating characteristic curve was generated to estimate the diagnostic performance of MR imaging. Heterogeneity was also tested. RESULTS: The systematic review identified 4 out of a total of 1300 studies to be included in the meta-analysis. On a per-pars basis (a total of 1122 pars), the pooled sensitivity and specificity of the MRI for the direct diagnosis of a pars defect were 81% (95% CI 54-94%) and 99% (95% CI 98-100%), respectively. A high overall heterogeneity (I2 = 79.5%) was computed with respective high and low heterogeneity on sensitivity (I2 = 87.9%) and specificity (I2 = 38.4%). CONCLUSIONS: This meta-analysis demonstrated a high diagnostic performance of MR imaging for the diagnosis of a pars defect in young adults. This technique may be considered as a first-line imaging technique as it helps to avoid exposure to ionising radiation.

An unusual radiologic manifestation of hypersensitivity pneumonia.

Hypersensitivity pneumonia is clinically suspected and can be characterized on computed tomography by its pattern of diffuse lung disease, in children, as in adults. However, identifying the diagnosis is not always as simple. We report an organizing pneumonia pattern of hypersensitivity pneumonia that can be seen in adult patients, but has not been reported in the pediatric population.

Thalamic Hemorrhagic Stroke in the Term Newborn: A Specific Neonatal Syndrome With Non-uniform Outcome.

BACKGROUND: Neonatal thalamic hemorrhagic stroke is related to cerebral sinus venous thrombosis and associated with neurological sequelae. Predicting factors are however lacking. METHODS: Clinical and radiological findings at onset and on follow-up of 5 neonates with thalamic hemorrhage stroke are described. RESULTS: All neonates presented with abrupt lethargy, ophistotonos, irritability and/or seizures. The thalamic hemorrhagic stroke was most often unilateral (4/5), involving the posterior/entire thalamus in 3 cases and the anterior thalamus in 2. Cerebral venous thrombosis was identified in a single patient. At follow-up, children with unilateral anterior thalamic hemorrhagic stroke demonstrated thalamic atrophy without neurological symptoms, whereas children whose thalamus lesion was extensive exhibit a porencephalic cavity and presented with late-onset epilepsy. DISCUSSION: Although deep cerebral venous thrombosis is probably the cause of neonatal thalamic hemorrhagic stroke, its radiological evidence is challenging. Outcome seems dependent of the size and location of thalamic hemorrhagic stroke. Epilepsy is a frequent morbidity after thalamic hemorrhagic stroke.