Pediatric-type diffuse low-grade glioma with T2-FLAIR mismatch sign: a case report and literature review.

INTRODUCTION: Pediatric-type diffuse low-grade gliomas are a new entity that was introduced in the fifth edition of the World Health Organization Classification of Tumors of the Central Nervous System, which was published in 2021. Notably, the information regarding the radiophenotypes of this new entity is limited. OBJECTIVE: T2-FLAIR mismatch sign has been mostly studied in adult-type diffuse gliomas so far. We aimed to present more pediatric cases for future research about T2-FLAIR mismatch signs in pediatric-type diffuse low-grade gliomas. CASE PRESENTATION: The current study presents a case of a 2-year-old boy who has a subcortical tumor at the right precentral frontal region. This tumor exhibited a T2-fluid-attenuated inversion recovery (FLAIR) mismatch sign that was identified as specific for isocitrate dehydrogenase (IDH)-mutant 1p/19q non-co-deleted astrocytomas. The tumor was pathologically identified as pediatric-type diffuse low-grade gliomas, and it tested negative for IDH-1 immunohistochemistry. The whole-exome sequencing of tumor tissue revealed negative results for IDH mutation, 1p/19q co-deletion, MYB rearrangement, and all other potential pathogenic mutations. CONCLUSION: The T2-FLAIR mismatch sign may not be 100% specific for IDH-mutant gliomas, especially in children, and researchers must further investigate the pathophysiology of the T2-FLAIR mismatch sign in brain tumors and the radiophenotypes of entities of pediatric brain tumors.

MRI of fatal course of acute hemorrhagic leukoencephalitis in a child with SARS-CoV-2 omicron BA 2.0 infection.

We present a pediatric case of acute hemorrhagic leukoencephalitis associated with SARS-CoV-2 Omicron BA 2.0 infection. A previously healthy girl presented with ataxia and diplopia three weeks after the COVID-19 confirmation from a nasopharyngeal swab. Acute and symmetrical motor weakness and drowsiness ensued within the following 3 days. She then became spastic tetraplegic. MRI revealed multifocal lesions in the cerebral white matter, basal ganglia, and brainstem, with hemorrhagic changes confirmed with T1-hyperintensity and hypointensity on susceptibility-weighted images. Peripheral areas of decreased diffusion, increased blood flow, and rim contrast enhancement were noted in the majority of lesions. She was treated with a combination of intravenous immunoglobulin and methylprednisolone pulse therapy. Neurological deterioration ensued with coma, ataxic respiratory pattern and decerebrate posture. Repeated MRI performed on day 31 revealed progression of abnormalities, hemorrhages and brain herniation. Despite the administration of plasma exchange, she died two months after admission.

Brain Abscess Apparent Diffusion Coefficient is Associated With Microbial Culture Yields.

BACKGROUND: Obtaining pus for microbial cultures is one of the surgical aims in patients with brain abscess. Predictors of microbial yields are necessary as they help in treatment planning. PURPOSE: To investigate the relationship between microbial culture yields of brain abscesses and their apparent diffusion coefficient (ADC) values and clinical characteristics. STUDY TYPE: Retrospective. SUBJECTS: Eighty-four patients diagnosed with brain abscess by surgery and histopathology (59 with positive abscess cultures). FIELD STRENGTH/SEQUENCE: Diffusion-weighted, T2-weigthed, and contrast-enhanced T1-weighted imaging at 1.5 T and 3 T. ASSESSMENT: Contrast-enhanced T1-weighted images were co-registered to ADC maps. Three neuroradiologists determined abscess imaging characteristics (distribution, location, and ventricular rupture), and two measured abscess volumes and ADC values. Clinical characteristics collected included sex, age, fever, underlying diseases, infection sources, white blood cell count, percentage of segmented neutrophils, C-reactive protein level, regimen and duration of empirical antibiotics, and types of surgery. STATISTICAL TESTS: Interobserver differences were assessed with Fleiss kappa and intraclass correlation coefficients. The differences in clinical and imaging factors between the positive and negative culture groups were compared with Chi-square analysis or Student's t test. All factors were subjected to multivariable logistic regression analysis to assess their associations with microbial culture yields, and factors with statistical significance were evaluated with receiver operating characteristic curve analysis to assess their diagnostic performance in discriminating the two groups. RESULTS: Mean ADC (×10-6  mm2 /s) of culture-negative abscesses (841 ± 173) was significantly higher (P < 0.05) than that of culture-positive abscesses (536 ± 90). On multivariable analysis, mean ADC was the only significant factor (P < 0.05) related to culture yields. With 660 as the cutoff value, the sensitivity, specificity, and accuracy of ADC for discriminating culture yields were 93.2%, 88.0%, and 91.7%, respectively. DATA CONCLUSION: ADC could be used to discriminate between culture-positive and culture-negative abscesses. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.

Arterial spin-labeling perfusion imaging of childhood encephalitis: correlation with seizure and clinical outcome.

PURPOSE: In childhood encephalitis, perfusion abnormalities have been infrequently reported to associate with clinical status. We investigated whether perfusion abnormalities correlated with seizure and clinical outcome in encephalitis. METHODS: We retrospectively analyzed the MR studies of 77 pediatric patients with encephalitis. Pseudo-continuous arterial spin-labeling (ASL) imaging was performed on a 3-T scanner. The patients were divided into five groups according to ASL perfusion imaging pattern: normal perfusion (NP), focal hypoperfusion (Lf), extreme global hypoperfusion (LE), focal hyperperfusion (Hf), and extreme global hyperperfusion (HE). Clinical outcome at 3 weeks was dichotomized to unfavorable or favorable outcome according to the Glasgow outcome scale. Multivariate logistic regression was conducted to predict unfavorable outcome and presence of seizure separately, based on explanatory variables including age, sex, and ASL pattern. RESULTS: Twenty-seven (35%) patients were designated as in group Hf, five (7%) in group Lf, 11 (14%) in group LE, none in group HE, and 34 (44%) in group NP. Multivariate logistic regression analysis showed that ASL pattern was significantly associated with unfavorable outcome (P = 0.005) and with presence of seizure (P = 0.005). For ASL pattern, group LE was 17.31 times as likely to have an unfavorable outcome as group NP (odds ratio confidence interval [CI] 3.084, 97.105; P = 0.001). Group Hf was 6.383 times as likely to have seizure as group NP (CI 1.765, 23.083; P = 0.005). CONCLUSIONS: In childhood encephalitis, patients with extreme global hypoperfusion had poor neurological outcome and those with focal hypoperfusion were more likely to have seizure.

Diffusion-Weighted Imaging of Periventricular Leukomalacia in Very Young Children: Assessment of Peritrigonal Stripe of Restricted Diffusion.

Purpose In periventricular leukomalacia (PVL), apparent diffusion coefficient (ADC) reduction, normally shown as dark stripe in the peritrigonal (PT) white matter, may be incomplete. We assessed the PT dark stripe to differentiate between PVL patients and control subjects. Patients and Methods We reviewed the magnetic resonance studies of 27 neonates and young children with PVL and 67 control subjects to assess the PT dark stripe on ADC maps. In PVL patients, the assessment was referred to the location of PVL lesion on fluid-attenuated inversion recovery (FLAIR) imaging. In the controls, the PT region or the location corresponding to FLAIR hyperintensity was evaluated for the dark stripe. We compared the prevalence of the dark stripe on ADC map and the PT FLAIR hyperintensity between the PVL and the control subjects. Results On ADC map, complete PT dark stripe was present in 67 (100%) of 67 controls but only in 4 (14.8%) of 27 PVL patients (p-value < 0.01), with sensitivity of 0.85, specificity of 1.0, and accuracy of 0.96. PT FLAIR hyperintensity was present in 44 (65.7%) of 67 controls and in 18 (66.7%) of 27 PVL patients (p = 0.920). Conclusion PVL patients can be differentiated from the control subjects with PT dark stripe on ADC map.

Arterial spin-labeling perfusion imaging of children with subdural hemorrhage: Perfusion abnormalities in abusive head trauma.

BACKGROUND AND PURPOSE: Perfusion abnormalities have not been well described in children with subdural hemorrhage (SDH). We investigated whether patients with abusive head trauma (AHT+) had more perfusion abnormalities than those without (AHT-). MATERIALS AND METHODS: We reviewed the perfusion MR studies of 12 infants with SDH and 21 controls. The perfusion images were obtained using a pseudo-continuous arterial spin-labeling sequence with volumetric fast spin-echo readout. An MR perfusion scoring system (0-6 points) was devised to facilitate appraisal of the extent of abnormalities. An asymmetry index (AI) was calculated for each region of perfusion abnormality. Comparison of perfusion scores across the AHT+, AHT-, and control groups was performed. The AIs of the hypoperfused lesions and hyperperfused lesions in patients were separately compared with those of the controls. The neurological outcomes of the patients were associated with imaging abnormalities. RESULTS: Perfusion abnormalities were found in five (83%) of six AHT+ patients and in one (17%) of six AHT- patients. The AHT+ group recorded a significantly higher perfusion score than did both the AHT- group and the controls. Four patients with hypoperfused lesions exhibited significantly lower AI (P=.002) than did the controls, and three patients with hyperperfused lesions had significantly higher AI (P=.006) than did the controls. Of the four patients with hypoperfused lesions, two expired and one experienced hemiparesis. CONCLUSIONS: Patients with AHT have higher perfusion abnormality scores than patients with other causes of SDH and controls. Moreover, hypoperfusion may suggest a poor clinical outcome.

Arterial spin-labeling perfusion imaging of childhood meningitis: a case series.

INTRODUCTION: Conventional magnetic resonance imaging (MRI), which is mainly used to detect complications, is ineffective in determining the neurological status of patients with meningitis. Hemodynamic change in the brain may be more indicative of the neurological status but few imaging studies have verified this. Arterial spin-labeling (ASL) perfusion, a noninvasive MR method requiring no contrast agent injection, can be used to measure cerebral blood flow (CBF). CASE REPORTS: We describe three pediatric patients with meningitis, who all showed regions of increased CBF on perfusion imaging. One patient, presenting with headache and conscious disturbance, had CBF changes in the frontal, temporal, and occipital regions. The other two patients, presenting with hallucinations, memory deficits, and seizures, had CBF changes in the frontal and temporal regions. CONCLUSION: ASL perfusion imaging may be helpful in assessing patients with meningitis, demonstrating CBF changes more strongly correlating with the neurological status, and detecting active brain abnormalities.

Spectrum of neuroimaging mimics in children with COVID-19 infection.

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has affected over 200 million people globally (including over 30 million people in the United States), with children comprising 12.9% of reported cases in the United States. In children, COVID-19 infection appears to be associated with mild respiratory symptoms; however, serious neurological complications may occur in conjunction with multisystem inflammatory syndrome. A wide spectrum of neurological diseases have been observed in children with COVID-19 infection including encephalitis, acute necrotizing encephalopathy, acute disseminated encephalomyelitis, cytotoxic lesion of the callosal splenium, posterior reversible encephalopathy syndrome, venous sinus thrombosis, vasculitis and infarction, Guillain-Barré syndrome, transverse myelitis, and myositis. This review describes the characteristic magnetic resonance neuroimaging features of these diseases and their differentiations from other imaging mimics. In addition, we review the possible pathophysiology underlying the association between these diseases and COVID-19-infection. As new SARS-CoV-2 variants emerge and COVID-19 infection continues to spread worldwide, pediatricians, radiologists, and first-line care givers should be aware of possible neurological diseases associated with COVID-19 infection when these reported neuroimaging patterns are observed in children during this pandemic.

Quantitative Analysis for the Delineation of the Subthalamic Nuclei on Three-Dimensional Stereotactic MRI Before Deep Brain Stimulation Surgery for Medication-Refractory Parkinson's Disease.

Delineation of the subthalamic nuclei (STN) on MRI is critical for deep brain stimulation (DBS) surgery in patients with Parkinson's disease (PD). We propose this retrospective cohort study for quantitative analysis of MR signal-to-noise ratio (SNR), contrast, and signal difference-to-noise ratio (SDNR) of the STN on pre-operative three-dimensional (3D) stereotactic MRI in patients with medication-refractory PD. Forty-five consecutive patients with medication-refractory PD who underwent STN-DBS surgery in our hospital from January 2018 to June 2021 were included in this study. All patients had whole-brain 3D MRI, including T2-weighted imaging (T2WI), T2-weighted fluid-attenuated inversion recovery (FLAIR), and susceptibility-weighted imaging (SWI), at 3.0 T scanner for stereotactic navigation. The signal intensities of the STN, corona radiata, and background noise were obtained after placing regions of interest (ROIs) on corresponding structures. Quantitative comparisons of SNR, contrast, and SDNR of the STN between MR pulse sequences, including the T2WI, FLAIR, and SWI. Subgroup analysis regarding patients' sex, age, and duration of treatment. We used one-way repeated measures analysis of variance for quantitative comparisons of SNR, contrast, and SDNR of the STN between different MR pulse sequences, and we also used the dependent t-test for the post hoc tests. In addition, we used Mann-Whitney U test for subgroup analyses. Both the contrast (0.33 ± 0.07) and SDNR (98.65 ± 51.37) were highest on FLAIR (all p < 0.001). The SNR was highest on SWI (276.16 ± 115.5), and both the SNR (94.23 ± 31.63) and SDNR (32.14 ± 17.23) were lowest on T2WI. Subgroup analyses demonstrated significantly lower SDNR on SWI for patients receiving medication treatment for ≥13 years (p = 0.003). In conclusion, on 3D stereotactic MRI of medication-refractory PD patients, the contrast and SDNR for the STN are highest on FLAIR, suggesting the optimal delineation of STN on FLAIR.

Prediction of Malignant Transformation of WHO II Astrocytoma Using Mathematical Models Incorporating Apparent Diffusion Coefficient and Contrast Enhancement.

Using only increasing contrast enhancement as a marker of malignant transformation (MT) in gliomas has low specificity and may affect interpretation of clinical outcomes. Therefore we developed a mathematical model to predict MT of low-grade gliomas (LGGs) by considering areas of reduced apparent diffusion coefficient (ADC) with increased contrast enhancement. Patients with contrast-enhancing LGGs who had contemporaneous ADC and histopathology were retrospectively analyzed. Multiple clinical factors and imaging factors (contrast-enhancement size, whole-tumor size, and ADC) were assessed for association with MT. Patients were split into training and validation groups for the development of a predictive model using logistic regression which was assessed with receiver operating characteristic analysis. Among 132 patients, (median age 46.5 years), 106 patients (64 MT) were assigned to the training group and 26 (20 MT) to the validation group. The predictive model comprised age (P = 0.110), radiotherapy (P = 0.168), contrast-enhancement size (P = 0.015), and ADC (P < 0.001). The predictive model (area-under-the-curve [AUC] 0.87) outperformed ADC (AUC 0.85) and contrast-enhancement size (AUC 0.67). The model had an accuracy of 84% for the training group and 85% respectively for the validation group. Our model incorporating ADC and contrast-enhancement size predicted MT in contrast-enhancing LGGs.

Neurological and endocrinological manifestations of 49 children with intracranial pure germinoma at initial diagnosis in Taiwan.

BACKGROUND: Intracranial pure germinoma is a rare extragonadal neoplasm. Affected patients may have motor impairment, visual disturbance, neurological signs, and endocrine disorder, depending on the size and location of the tumor. This study investigated and analyzed patients' demographic data and neuroimaging, clinical, laboratory, and endocrinological findings. METHODS: We performed a retrospective chart review of 49 children diagnosed with pure germinoma in Taiwan from 1990 to 2018. The initial clinical presentation, tumor markers (beta-hCG, alpha fetoprotein, and carcinoembryonic antigen), pituitary function, and brain images were reviewed and analyzed. RESULTS: This study included 49 patients (37 boys and 12 girls). Their ages ranged from 7.5 to 17.9 years, and the mean age at diagnosis was 13.6 years. Initial symptoms included visual disturbance (n = 23, 47.9%), motor impairment (n = 20, 40.8%), polyuria (n = 20, 40.8%), headache (n = 17, 34.7%), dizziness or vertigo (n = 14, 28.6%), nausea/vomiting (n = 13, 26.5%), and short stature (n = 8, 18.2%). Laboratory data indicated growth hormone deficiency or low IGF-1 levels (n = 18, 85.7%), adrenal insufficiency (n = 21, 77.8%), central diabetes insipidus (n = 27, 55.1%), central hypothyroidism (n = 15, 48.4%), and hypogonadotropic hypogonadism (n = 4, 44.4%). CONCLUSION: Intracranial pure germinomas may initially manifest as neurological symptoms or endocrinological findings at diagnosis. As endocrinologic presentation is related to delayed diagnosis, clinicians should be aware of patients with such complaints. Laboratory data should be surveyed carefully, and neuroimaging must be considered if the result is abnormal.

Craniocervical arterial dissection: a cause of childhood arterial ischemic stroke in Taiwan.

BACKGROUND/PURPOSE: To describe the clinical characteristics and imaging findings of craniocervical dissection in childhood ischemic stroke, in a tertiary medical center. METHODS: In this retrospective study, we investigated children (aged 1 month to 18 years) with symptoms and radiographic confirmation of ischemic stroke from January 1996 to January 2007. Stroke work-up included neuroimaging (magnetic resonance imaging, computed tomography, conventional angiography, and magnetic resonance angiography), cardiac assessment, prothrombotic assays, immunoassays, infection screening, and metabolic screening. RESULTS: Among 95 children with arterial ischemic stroke, arterial dissection was identified as the underlying risk factor in nine patients (7 boys and 2 girls; age range, 1.9 17.2 years). All the patients had focal neurological signs and two had warning symptoms. A history of trauma was noted in two patients and another two had stroke during physical exertion. The other five patients had spontaneous dissection. Six patients had anterior circulation arterial dissection. Three patients had posterior circulation arterial dissection, and the most common location was in the vertebral artery. Antiplatelet treatment was given to five patients and anticoagulants to one. Endovascular treatment was given to one patient with dissecting aneurysm. One patient died at the acute stage and another seven had neurological deficits after 9 months to 8 years follow-up. The ninth patient had no residual neurological impairment. No patients had recurrent stroke. CONCLUSION: Arterial dissection should be considered in childhood ischemic stroke. Spontaneous arterial dissection is an important factor in this group. Early investigation and treatment can improve the outcome.

Rhombencephalitis in Children: Diffusion Magnetic Resonance Imaging (MRI) Correlation With Clinical Outcomes.

In children with rhombencephalitis, neuroimaging abnormalities have been infrequently correlated with clinical outcome. We investigated whether magnetic resonance (MR) neuroimaging studies could predict clinical outcomes and disturbance of consciousness in patients with rhombencephalitis. We retrospectively analyzed the MR studies of 19 pediatric patients with rhombencephalitis (median age: 4.2 years, range 0.5-17; sex: 32% male). Fluid-attenuated inversion recovery imaging and diffusion-weighted imaging findings were graded to create imaging scores according to the extent of imaging abnormality. Clinical outcomes in the first week and 12th month were graded by using Glasgow Outcome Scale scores (1-5) and dichotomized to unfavorable or favorable outcome. Correlations of the imaging scores with the clinical outcomes and with disturbance of consciousness were assessed by using multivariate logistic regression analysis. No significant correlation was found between fluid-attenuated inversion recovery score or diffusion-weighted imaging score (P = .608, P = .132, respectively) and disturbance of consciousness. In the first week, the unfavorable outcome group (n = 11) had significantly higher diffusion-weighted imaging score than did the favorable outcome group (n = 8) (Mann-Whitney U test, P = .005). Multivariate logistic regression analysis showed that the diffusion-weighted imaging score (odds ratio, 18.182; 95% confidence interval: 1.36, 243.01; P = .028) was significantly associated with unfavorable outcome. In the 12th month, the fluid-attenuated inversion recovery score or diffusion-weighted imaging score (P = .994, P = .997, respectively) were not significantly associated with unfavorable outcome. Patients with rhombencephalitis who have a higher diffusion-weighted imaging score are more likely to have an unfavorable 1-week clinical outcome.

Treatment of cerebellopontine angle tumors in children: a single institution's experience.

The authors discuss the current management for cerebellopontine angle (CPA) tumors in children. CPA tumors accounted for 1% to 3% of intracranial tumors in children. There had been much controversy with the management of these tumors. A total of 29 eligible patients were enrolled to the study and 5 patients had multiple lesions at diagnosis. Eight patients with tumors exclusively confined in the CPA. Sixteen patients with tumors occurred predominantly within CPA and 5 arising from the vicinity and growing mainly into the CPA. Twelve tumors were located in the right CPA (41%) and 5 (17%) on the left. Thirteen of the 29 patients developed hydrocephalus and 3 required placement of a shunt. Lesions of the CPAs were divided into those native to the angle and those extending to the angle from adjacent structures. Gross total removal was achieved in 9 cases, subtotal in 14, and 2 had biopsies only. Four patients were diagnosed with pontine glioma solely by magnetic resonance imaging without histologic confirmation. Two died soon after the operation. Ten patients died with a mortality rate of 34.5%. The median follow-up in this study was 38 months (range: 4 to 225 mo). The CPA is a rare location for lesions in children, with clear predominance on the right side. Although low-grade lesions are more frequent, the histology varies widely and is limited by the lack of radiologic-pathologic correlation.

Arterial spin-labeling magnetic resonance imaging of brain maturation in early childhood: Mathematical model fitting to assess age-dependent change of cerebral blood flow.

PURPOSE: To determine the trajectory of age-dependent cerebral blood flow (CBF) change in infants and young children by fitting mathematical models to the imaging data. METHODS: In this retrospective study, we reviewed the arterial spin-labeling imaging studies of 49 typically developing infants and young children at postmenstrual age (PMA) ranging from 38 to 194 weeks. All patients had normal structural MR imaging. Coregistration and gray matter segmentation were performed to extract whole-brain CBF values. Regional CBF values were obtained using manual region-of-interest placement. Curve estimation regression procedures with the corrected Akaike information criterion (AICc) were performed to determine the mathematical model best fitting the relationship between the CBF (whole-brain and regional measurements) and PMA of the patients. RESULTS: Whole-brain CBF trajectory was best fitted by a cubic model (AICc = 215.95; R2 = 0.566; P < .001). Whole-brain CBF at 1, 6, 12, and 24 months was estimated to be 36, 52, 58, and 55 mL/100 g/min, respectively. Regional CBF trajectory was also best fitted by a cubic model in the frontal (AICc = 233.63; R2 = 0.442; P < .001), parietal (AICc = 229.18; R2 = 0.614; P < .001), basal ganglion (AICc = 239.39; R2 = 0.178; P = .043), temporal (AICc = 236.01; R2 = 0.441; P < .001), and occipital (AICc = 236.46; R2 = 0.475; P < .001) regions. CONCLUSIONS: In early childhood, the trajectory of CBF change was nonlinear and best fitted by the cubic model for the whole brain and all brain regions.

Occult infarct with acute hemorrhagic stroke in juvenile diabetic ketoacidosis.

Diabetes ketoacidosis (DKA) is one of the common complications of type I insulin-dependent diabetes mellitus. Neurological deterioration during an episode of DKA is usually assumed to be caused by cerebral edema and cerebral vascular accidents. However, hemorrhagic stroke is a very rare complication of juvenile DKA. We describe a girl who had newly diagnosed insulin-dependent diabetes mellitus with juvenile DKA developed intracerebral hemorrhage.

Risk factors and outcomes of childhood ischemic stroke in Taiwan.

In this retrospective study, we reviewed the charts and collected clinical and radiographic data on children (age range, 1 month to 18 years) with symptoms and radiographic confirmation of ischemic stroke for the period of January 1996 to July 2006. Ninety-four children were enrolled. Eighty-eight had arterial ischemic stroke and six had sinovenous thrombosis. Twenty-nine percent of the children had seizures. Twenty-six percent had diffuse neurological signs and 76% had focal neurological signs. Risk factors included vascular disease (33%), infection (27%), metabolic disorders (18%), trauma (11%), prothrombotic states (13%), cardiac disease (10%), and mitochondrial disease (6%). Ten percent (n=9) had no identifiable cause. Twenty-two percent of the children had more than one risk factor. Anterior territory (70%) was more involved than posterior territory (18%) in arterial ischemic stroke. Unilateral infarctions were more common on the left side (51%) than on the right (24.5%). Neurological deficits were present in 45% (n=34/75) of the children; the most frequent deficit was motor impairment (24%). Seven children (9%) died in the acute stage. There were 12 children (16%) who had recurrent stroke and 8 children (8/12) who had underlying vascular disease. The vascular disease included moyamoya disease (5), CNS lupus (1) and ill-defined vasculopathy (2). The etiology pattern in Taiwan was different from that in Western countries. Vascular disease was a significant risk factor for recurrence in childhood ischemic stroke.

Cerebellar infarction in the territory of the superior cerebellar artery in children.

Posterior circulation infarction is uncommon in children. Vertebral artery dissection is an unusual cause of posterior circulation infarction in children. We report on a 12-year-old boy with spontaneous left-extracranial vertebral artery dissection associated with isolated ipsilateral superior cerebellar artery territory infarction, diagnosed clinically and by brain computed tomography, magnetic resonance imaging, and magnetic resonance angiography. Cerebral angiography demonstrated a flame-like occlusion of the left vertebral artery at level C(2)-C(3), and indicated that artery-to-artery embolus may be a mechanism of superior cerebellar artery territory infarction. We emphasize that vertebral artery dissection should be considered in a child with acute signs of posterior circulation ischemia.

Computed tomography findings in fatal cases of enormous hepatic portal venous gas.

AIM: To assess the computed tomography (CT) findings in the patients with hepatic portal venous gas (HPVG) who presented with a short fatal clinical course in our hospital in order to demonstrate if there was any sign for prediction. METHODS: Between January 1997 and December 2000, CT scan of the abdomen was performed on 949 patients with acute abdominal pain in our emergency department. Five patients were found having HPVG. The CT images and clinical presentations of all these five patients were reviewed. RESULTS: In reviewing the CT findings of the cases, HPVG in bilateral hepatic lobes, abnormal gas in the superior mesenteric veins, small bowel intramural gas, and bowel distension were observed in all patients. Dry gas in multiple branches of the mesenteric vein was also revealed in all cases. All the patients expired due to irreversible septic shock within 48 h after their initial clinical presentation in emergency room. Two patients had acute pancreatitis with grade D and E Balthazar classification and they expired within 24 h due to progressing septic shock under aggressive medical treatment and life support. Two patients with underlying end stage renal disease expired within 48 h even though emergent surgical intervention was undertaken. The excited bowels revealed severe ischemic change. One patient expired only a few hours after the CT examination. CONCLUSION: HPVG is a diagnostic clue in patients with acute abdominal conditions, and CT is the most specific diagnostic tool for its evaluation. The dry mesenteric veins are the suggestive fatal sign, especially for the deteriorating patients, with the direct effect on gastrointestinal perfusion.

Prenatal diagnosis of choledochal cyst using magnetic resonance imaging: a case report.

Choledochal cysts are congenital anomalies of the biliary ducts, characterized by cystic dilatation of the ducts. Prenatal diagnosis of this anomaly using ultrasonography (US) has been well documented. Magnetic resonance imaging (MRI) has recently become an important complement to US in prenatal diagnosis of fetal anomalies. We herein report a patient in whom at 24 wk' gestation US suggested a right upper quadrant abdominal cyst and in whom at 26 wk' gestation MRI more clearly delineated the cyst and its surrounding structures and suggested a choledochal cyst, which was confirmed at postnatal surgery and histopathology.