Normal Magnetic Resonance Angiography Research Articles

5613354 SCREENING FOR CEREBROVASCULAR DISEASE IN CHILDREN WITH SICKLE CELL DISEASE USING TRANSCRANIAL DOPPLER AND MRA TO PREVENT STROKE: THE AMSTERDAM COHORT

Background: Cerebrovascular complications are the most devastating complications in patients with Sickle Cell Disease (SCD). To identify patients at risk of a first cerebrovascular accident (CVA), the American Society of Hematology (ASH) 2020 guideline for SCD recommends annual transcranial Doppler ultrasonography (TCD) screening for children aged 2-16 years with HbSS or HbSβ0 thalassemia. When abnormal TCD velocities are detected, chronic transfusion therapy is advised for at least a year.(1) Since 2000 we have implemented a different management protocol in Amsterdam that only prescribes transfusion therapy for children with confirmed MRA abnormalities when increased flow is present on TCD measurement. This Amsterdam protocol reduces exposure to chronic blood transfusions but we need to investigate the safety and efficacy. Methods: In this longitudinal single center cohort study, all patients managed according to the Amsterdam Protocol between January 2000 and September 2022 were included. TCD screening was performed in children with genotypes SS or Sβ0-thalassemia at a frequency of twice a year in the age group 4-10 years and annually in children aged 10 to 18 years. From January 1st 2010 onwards, screening was already initiated at the age of 2 years. When TCD screening demonstrated abnormal results at 2 separate assessments, magnetic resonance angiography (MRA) was performed. We only started chronic transfusion therapy in patients with a stenotic lesion present on MRA. In patients without abnormalities on MRA follow-up by TCD according to protocol was continued. Results: A total of 209 SCD patients were included in this study, cumulative 2874.5 patient-years of follow-up. The median age of these patients at the start of the follow-up was 0.74 (IQR: 0.0, 5.5) years. In this cohort, 30 patients had abnormal TCD results at 2 separate assessments. In all of these patients MRA was performed, which showed abnormal results in 16 cases. None of the 12 patients with abnormal TCD results and normal MRA results who did not receive chronic transfusion therapy developed a CVA. The total follow-up duration after the first abnormal TCD in these patients was 112.0 patient-years. Nine out of the 14 patients (64%) who had abnormal TCD results used hydroxyurea. The median time between the first abnormal TCD and initiation of hydroxyurea therapy was 3.9 (IQR: 3.0, 5.2) years. Two patients with abnormal TCD and normal MRA results were treated with chronic transfusion therapy. In these cases, chronic transfusion therapy was started because of recurrent acute chest syndrome (ACS) and abnormal TCD results (despite normal MRA results) respectively. Discussion: These data suggest that treatment according to the Amsterdam Protocol is a safe and efficient way to prevent primary stroke in children with SCD and to reduce exposure of these patients to long term transfusion therapy. Although the group of patients in this cohort with abnormal TCD velocities and normal MRA that did not receive transfusion therapy is limited to 12 patients with cumulative 112.0 patient-years of follow-up, we believe the results of this study are reassuring, since the cumulative incidence rate in this study is significantly lower (0.0 (95% CI: 0.0, 0.25)) compared to the incidence reported for patients with abnormal Doppler results in the original study by Adams et al. (0.4 (95% CI: 0.27, 0.59) at 30 months).(2)

Should Primary Stroke Centers Perform Advanced Imaging?

Should Primary Stroke Centers Perform Advanced Imaging?

Women With First-Hand Tobacco Smoke Exposure Have a Higher Likelihood of Having an Unruptured Intracranial Aneurysm Than Nonsmokers: A Nested Case-Control Study.

The prevalence of unruptured intracranial aneurysms (UIA) in females who smoke cigarettes and the association between smoking and hypertension with purely incidental UIAs have been unexplored. To obtain the prevalence of UIA among females and to assess the relationship between smoking and hypertension with a diagnosis of incidental UIAs. A nested case-control study from a cohort of female patients aged between 30 and 60 yr with a brain magnetic resonance angiography (MRA) between 2016 and 2018. Incidental UIAs were compared to patients with normal MRAs. Smoking was characterized as never or former/current smokers. A logistic regression was used to evaluate the association between smoking, hypertension, or both, with a diagnosis of incidental UIAs. A total of 1977 patients had a brain MRA between 2016 and 2018. From 1572 nonsmoker patients, we encountered 30 with an UIA (prevalence: 1.9%). There were 405 patients with a positive smoking history, and 77 patients harbored an UIA (prevalence: 19%). Of 64 aneurysm patients and 130 random controls eligible for the case control, aneurysm patients were more likely to have a positive smoking history and hypertension compared with healthy controls (60%vs 18%, P≤.001; 44%vs 14%, P≤.001). A multivariable analysis demonstrated a significant association between a smoking history, hypertension, or both factors with an incidental UIA (odds ratio [OR] 5.8 CI 1.22-11.70; OR 3.8 CI 2.31-14.78; OR 12.6 CI 4.38-36.26; respectively). Females who smoke cigarettes have a higher prevalence of UIAs than the general population. Smoking confers a higher risk for having a silent UIA, aggravated by hypertension. This population is an ideal target for potential screening.

Neurovascular changes in magnetic resonance imagining and single-photon emission computed tomography during migraine attack in patients with FHM2 mutations

The aim of this article is to provide neuroimaging data on cases with familial hemiplegic migraine (FHM). A 14-year-old male presented normal diffusion-weighted magnetic resonance imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) findings during his first hemiplegic migraine attack. However, magnetic resonance angiography (MRA) showed diffuse narrowing of the right middle cerebral artery. Cerebral blood flow–single-photon emission computed tomography showed right hypoperfusion. A follow-up study showed no abnormal findings. His mother had normal DWI, FLAIR, and MRA findings during her migraine attack. Both patients were diagnosed with FHM2 (p.R763H mutation in ATP1A2). This study highlights the importance of neurovascular examinations during the FHM2 headache phase. Further cases are required to clarify the pathophysiology of migraine.

Automated Evaluation of Intracranial Vessel Morphology in Normal Versus Pediatric Moyamoya Disease

Abstract INTRODUCTION Evaluation of intracranial artery morphology plays an important role in diagnosing a variety of neurovascular diseases. In addition to clinical symptoms, diagnosis currently relies on qualitative rather than quantitative evaluation of vascular imaging sequences such as magnetic resonance angiography (MRA). However, previously described statistical cerebroarterial atlases have focused primarily on healthy adults and little information exists about what constitutes normal artery morphology in the pediatric population and across brain development. We aimed to quantitatively assess normal, age-related changes in artery morphology and compare normal morphology to that of children with Moyamoya disease (MMD). METHODS MRAs from 98 children (49 M/49F) aged .6 to 20 yr (median = 11.5 yr) with normal MRAs and and 18 children with radiographically confirmed MMD (10 M/8 F, median age = 7.1 yr) were retrospectively collected. All arteries were automatically segmented in both MRA datasets. Using an atlas-based approach, the radiuses of the main arteries of the anterior circulation (internal carotid artery (ICA), anterior cerebral artery (ACA), and middle cerebral artery (MCA)) and posterior circulation (PCA, BA) were measured at corresponding locations. Artery radii were compared between the 2 groups using MANCOVA with age and sex as covariates. RESULTS The artery radius was relatively consistent across age for all main arteries in normal patients. MANCOVA revealed that children with MMD exhibit significantly smaller ICA, MCA-M1, MCA-M2, and ACA radii (P < .001) compared to normal controls (mean vessel radii: ICA 1.27 vs 1.64 mm, MCA M1 0.92 vs 1.14 mm, MCA M2 0.66 vs 0.82 mm, ACA 0.72 vs 0.83 mm). There were no significant differences in the posterior circulation radii. CONCLUSION We present normal artery morphology data for children based on automatic segmentation of MRAs, and demonstrate that artery caliber is smaller in children with MMD. This resource will allow neurosurgeons to quantitatively assess MMD and the impact of bypass surgery on disease progression.

Cerebral Infarcts and Cerebrovascular Disease in Neurologically Intact Tanzanian Children with Sickle Cell Anaemia

Introduction:Children and adolescents with sickle cell anemia (SCA) without history of neurological manifestations remain at risk of stroke and require cost effective screening as evidence-based stroke prevention interventions are developed. Although there are data on the prevalence of Transcranial Doppler (TCD) abnormality, there are relatively few studies on the prevalence of silent cerebral infarction (SCI) on magnetic resonance imaging (MRI) and vasculopathy on MR angiography (MRA), paricularly in Africa, where the burden of disease is greatest. In this study in Africa, we determined the prevalence of SCI on MRI and cerebral vasculopathy on MRA, and explored associations with age, sex, internal carotid/middle cerebral artery (ICA/MCA) and basilar cerebral blood flow velocities (CBFV) on TCD, and hematological variables.Patients and methods:We prospectively studied children with homozygous SCA (HbSS) without prior clinically overt stroke or TIA or seizures. Clinical information and blood for full blood count was collected for all patients. All were offered TCD using non-imaging equipment (Compumedics) and MRI and MRA of intracranial arteries on a Philips 1.5 Tesla scanner. MRA was graded as 1 Turbulence, 2 Stenosis, 3 Occlusion, 4 Occlusion with collaterals (moyamoya). Imaging was reviewed by 2 neuroradiologists (MJ and DS) and consensus was reached.Results:Within a period of 12 months, 395 children with SCA were recruited. Mean age was 12.7+/-4 (range 5-19 years); 199 (50.4%) were male. Mean hemoglobin was 7.6±1.1 (range 4.1-13.5) g/dl. 381 had TCD, of whom 227 (57%) have had brain MRI and MRA so far.Only 14/395 (3.5%) of patients had abnormal CBFV, 8 (2%) with maximum CBFV <50 cm/sec, 3 with CBFV 150-169 cm/sec, 1 with conditional (170-199 cm/sec) and 2 (0.5%) with abnormal CBFV (>200cm/sec).Prevalence of silent cerebral infarction was 29% (65/227) and was similar in males (30%; 34/114) and females (28%; 31/110) but was lower in children aged <9 years (20%; 10/51) than in those aged 10-14 years (33%; 27/83) or those aged 15-19 years (32%; 28/89); this was not significant (p=0.2).The prevalence of cerebral vasculopathy on MRA, defined as stenosis (Grade 2), occlusion (Grade 3) or occlusion with collaterals (moyamoya; Grade 4), was 9% (20/227). The internal carotid and/or middle cerebral artery was affected in all 20 and the anterior cerebral artery was affected in 7 patients. Vasculopathy was not observed on MRA in the posterior cerebral artery and no patients had moyamoya. An additional 9 (4%) patients had turbulence (Grade 1) in at least one artery on MRA.SCI were more common in those with MRA vasculopathy Grades 2-3 (12/64; 19%) and in those with Grade 1 Turbulence (2/9; 22%) than in those with normal MRA (8/165; 5%) (p<0.05). Patients with Grade 1 Turbulence had higher ICA/MCA CBFv (mean 122+/-36 cm/sec) than those with normal MRA (mean 101+/-25 cm/sec) or Grades 2-3 (mean 109+/-21 cm/sec) vasculopathy. The difference in those with Grade 1 turbulence compared with those with normal MRA was significant (mean difference 20 cm/sec, 95% confidence intervals 1, 39 cm/sec; p=0.037). Basilar velocity was also significantly higher in those with Grade 1 turbulence (87+/-21 cm/sec) than in those with normal MRA (76+/-14 cm/sec) and those with Grade 2-3 vasculopathy (80+/-11 cm/sec)(mean difference 11.5 cm/sec, 95% confidence intervals 0.3, 22.6 cm/sec; p=0.043). Basilar velocity weakly correlated with hemoglobin (r=-0.18) but the relationships between hemoglobin and ICA/MCA CBFV or either presence of SCI or MRA abnormality were not significant.Conclusions:The prevalence of SCI on MRI is high in children with SCA without neurological history living in Africa even when TCD CBFV is normal. Children and adolescents with all grades of vasculopathy on MRA are at higher risk of brain parenchymal injury. The lack of association between SCI and hemoglobin may be related to the relatively severe anemia in our African study. As MRA contrast depends on velocity of blood flowing in vessels, it is not surprising that Grade 1 turbulence on MRA appears to reflect high CBFV on TCD. Importantly, high TCD velocity and Grade 1 turbulence may reflect the potentially reversible early stages in the development of SCA vasculopathy when cerebral blood flow is high before stenosis and occlusion supervene. TCD is operator dependent and there may be a case for MRI and MRA screening if follow-up shows that these measures predict stroke. DisclosuresNo relevant conflicts of interest to declare.

Arterial Wall Imaging in Pediatric Stroke.

Arteriopathy is common in childhood arterial ischemic stroke (AIS) and predicts stroke recurrence. Currently available vascular imaging techniques mainly image the arterial lumen rather than the vessel wall and have a limited ability to differentiate among common arteriopathies. We aimed to investigate the value of a magnetic resonance imaging-based technique, namely noninvasive arterial wall imaging (AWI), for distinguishing among arteriopathy subtypes in a consecutive cohort of children presenting with AIS. Children with confirmed AIS and magnetic resonance angiography underwent 3-Tesla AWI including T1-weighted 2-dimensional fluid-attenuated inversion recovery fast spin echo sequences pre- and post-gadolinium contrast. AWI characteristics, including wall enhancement, wall thickening, and luminal stenosis, were documented for all. Twenty-six children with AIS had AWI. Of these, 9 (35%) had AWI enhancement. AWI enhancement was associated with anterior circulation magnetic resonance angiography abnormality and cortical infarction in 8 of 9 (89%) children and normal magnetic resonance angiography with posterior circulation subcortical infarction in 1 (1 of 9; 11%) child. AWI enhancement was not seen in 17 (65%), 10 (59%) of whom had an abnormal magnetic resonance angiography. Distinct patterns of pre- and postcontrast signal abnormality were demonstrated in the vessel wall in the region of interest in children with transient cerebral arteriopathy, arterial dissection, primary central nervous system angiitis, dissecting aneurysm, and cardioembolic stroke. AWI is a noninvasive, high-resolution magnetic resonance AWI technique, which can be successfully used in children presenting with AIS. Patterns of AWI enhancement are recognizable and associated with specific AIS pathogeneses. Further studies are required to assess the additional diagnostic utility of AWI over routine vascular imaging techniques, in childhood AIS.

Utility of Neurovascular Imaging in Acute Neonatal Arterial Ischemic Stroke

To evaluate the prevalence of magnetic resonance angiography (MRA) findings and clinically characterize neonates with arterial ischemic stroke (AIS) who have abnormal or variable vasculature. This was a single-center, retrospective study of patients with neonatal stroke from 1991 to 2012. We reviewed charts and neuroimaging, including MRA, in neonates with AIS. Clinical data of patients with MRA findings were compared with the control group of neonates with AIS and a normal MRA. We identified 142 cases of neonatal AIS, of which 81 patients had magnetic resonance imaging and MRA. Among the neonates with arterial neuroimaging, 29 had arterial findings (for a prevalence rate of 20%-35%). The majority of the findings were stenotic or hypoplastic branches. Two patients had presumed carotid artery dissection. Low Apgar scores and the presence of sepsis were significantly (P <.05) more common in neonates with MRA findings. The prevalence of arterial abnormalities or variations in neonatal AIS has been underestimated because neurovascular imaging is often not performed. We recommend an MRA for neonates with AIS, particularly those who have low Apgar scores and/or sepsis, to rule out a vasculopathy that may warrant therapeutic intervention.

A stress-related explanation to the increased blood pressure and its course following ischemic stroke

BackgroundA hypertensive response after ischemic stroke is frequent, yet its pathophysiology is unknown. Mechanisms related to local ischemic damage, major vascular occlusion, and psychological stress due to acute illness have been proposed. We assessed the natural course of blood pressure (BP) within the first 24 h in groups of ischemic stroke patients with different characteristics. We hypothesized that a consistent BP reduction, regardless of stroke location, time window from debut to admission and presence of persistent vascular occlusion, would favor a stress-related mechanism as an important cause of the hypertensive response after ischemic stroke.MethodsIschemic stroke patients (n=1067) were prospectively registered, and BP was measured on admission and <3 h, 3–6 h, 6–12 h and 12–24 h after admission. Patients were categorized according to the location of diffusion-weighted imaging (DWI) lesions (cortical, large subcortical, mixed cortico-subcortical, lacunar, cerebellar, brain stem or multiple), time window (admitted within or after 6 h of symptom onset) and presence of persistent proximal middle cerebral artery (MCA) occlusion versus normal findings on magnetic resonance angiography (MRA) at 24 h.ResultsA reduction in systolic BP and diastolic BP from baseline to 12–24 h was found across all DWI locations except for diastolic BP in cerebellar (P=0.072) lesions. Apart from diastolic BP in patients with normal MRA findings at 24 h (P=0.060), a significant fall in systolic BP and diastolic BP at 12–24 h was registered, irrespective of whether patients were admitted within 6 h or after 6 h of stroke onset or had persistent MCA occlusion versus normal MRA findings.ConclusionWe found a relatively consistent decline in BP within 24 h after admission across different stroke locations in patients admitted within or after 6 h of stroke onset and in patients with persistent MCA occlusion. Our findings suggest that a systemic factor such as psychological stress may be an important contributor to the frequently elevated BP on admission in patients with ischemic stroke.

Changes to the geometry and fluid mechanics of the carotid siphon in the pediatric Moyamoya disease

Background: The Moyamoya disease is a cerebrovascular disease that causes occlusion of the distal end of the internal carotid artery, leading to the formation of multiple tiny collateral arteries. To date, the pathogenesis of Moyamoya is unknown. Improved understanding of the changes to vascular geometry and fluid mechanics of the carotid siphon during disease may improve understanding of the pathogenesis, prognosis techniques and disease management. Methods: A retrospective analysis of Magnetic Resonance Angiography (MRA) images was performed for Moyamoya pediatric patients (MMD) (n = 23) and control (Ctrl) pediatric patients (n = 20). The Ctrl group was composed of patients who complained of headache and had normal MRA. We performed segmentation of MRA images to quantify geometric parameters of the artery. Computational fluid dynamics (CFD) was performed to quantify the hemodynamic parameters. Results: MMD internal carotid and carotid siphons were smaller in cross-sectional areas, and shorter in curved vascular length. Vascular curvature remained constant over age and vascular size and did not change between Ctrl and MMD, but MMD carotid siphon had lower tortuosity in the posterior bend, and higher torsion in the anterior bend. Wall shear stress and secondary flows were significantly lower in MMD, but the ratio of secondary flow kinetic energy to primary flow kinetic energy were similar between MMD and Ctrl. Conclusion: There were alterations to both the geometry and the flow mechanics of the carotid siphons of Moyamoya patients but it is unclear whether hemodynamics is the cause or the effect of morphological changes observed.

MR angiography findings in infants with neonatal arterial ischemic stroke in the middle cerebral artery territory: A prospective study using circle of Willis MR angiography

AimNeonatal arterial ischemic stroke (NAIS) results from a focal disruption of the blood flow in a cerebral artery by a not well understood mechanism. Our objective is to describe the acute MRangiography (MRA) findings in infants with an NAIS in the middle cerebral artery (MCA) territory and correlate them with early parenchymal infarcts and motor outcome. MethodsAmong one hundred prospectively followed neonates with NAIS, we studied thirty-seven patients with an MCA infarct explored with circle of Willis MRA. MCA flow characteristics were documented, along with infarct location/extent and motor outcome at age 7 years. ResultsTwenty-three (62%) of the children showed arterial changes, all ipsilateral to the NAIS, with occlusion in six, thrombus-type flow defect in nine, and unilateral increased flow in enlarged insular arteries in the remaining eight. There was a statistically significant correlation between parenchymal and arterial MR findings (p=0.0002). A normal MRA had a negative predictive value of 100% (95% CI: 76.8-100) in ruling out a main branch infarct. Patients with abnormal MRA tended to be at increased risk for cerebral palsy (OR=3.1). Occlusion was associated with a worse outcome (p=0.04). InterpretationMRangiography shows arterial abnormalities suggesting that embolism is a frequent cause of NAIS.

Detection of Cerebral Vasculopathy by Transcranial Doppler in Children With Neurofibromatosis Type 1.

Neurofibromatosis type 1 is characterized by nerve sheath neurofibromas associated with a number of additional clinical features, including cerebrovascular disease. The aim of this study was to use transcranial Doppler as a screening method for identifying cerebral vasculopathy in children with neurofibromatosis type 1. Forty children with neurofibromatosis type 1, aged 5 to 18 years old, were examined by transcranial Doppler. Patients presenting with hemodynamic features of arterial stenosis/occlusion on transcranial Doppler underwent magnetic resonance angiography to confirm the findings. Magnetic resonance angiography was performed on 4 children who exhibited a transcranial Doppler hemodynamic pattern indicative of cerebral vasculopathy. Among these cases, 2 presented internal carotid artery stenosis/occlusion, 1 had bilateral middle cerebral artery stenosis, and 1 presented a normal magnetic resonance angiography result. Transcranial Doppler can be used routinely in the investigation of cerebrovascular disease in neurofibromatosis type 1 patients, where magnetic resonance angiography can be subsequently applied to confirm the diagnosis, further contributing to the prevention of cerebrovascular events.

Um caso de midríase episódica benigna

Introduction: Anisocoria requires exclusion of serious neurological pathology but it may also be a benign and self – limiting condition, as in cholinergic blockade of the pupillary sphincter by parasympatheticolytic substances or in rare conditions such as benign episodic mydriasis. Case description: A 22 year-old male farm worker presented in June 2014 with decreased visual acuity and ‘foggy vision’ in the right eye. There was no history of contact with toxins. Examination revealed unilateral mydriasis of the right pupil and decrease in the pupillary light reflex and in the ipsilateral accommodation - convergence reflex. No changes were noted in extra-ocular movements or in the position of the eyelids. No other abnormalities were found on physical examination. The patient was referred to the Ophthalmology Emergency Department where he underwent further examination that did not reveal additional findings. Comment: A negative history of contact with toxins, the absence of other neurological signs or symptoms, and a normal magnetic resonance angiography study support a diagnosis of benign episodic mydriasis. This is a rare condition, which appears to be related to autonomic dysfunction. It is important for family physicians to be aware of this condition, to know how to perform a correct clinical examination, and to refer the patient for additional testing to exclude other diagnoses. Patients require reassurance that the condition is benign and proper follow-up for possible recurrence.

Spontaneous intracranial hypotension presenting as thunderclap headache: a case report

BackgroundSpontaneous intracranial hypotension is a rare but treatable cause of a disabling headache syndrome. It is characterized by positional orthostatic headache, pachymeningeal enhancement and low cerebrospinal fluid pressure. However, the spectrum of clinical and radiographic manifestations is varied and misdiagnosis is common even in the modern era of magnetic resonance imaging. Spontaneous intracranial hypotension presenting as thunderclap headache is recognized but rare.Case presentationA 41-year-old Sri Lankan female presented with thunderclap headache associated with nausea and vomiting, but the headache was characterized by positional variation with aggravation in the upright posture and relief in the supine posture. Gadolinium-enhanced cranial magnetic resonance imaging demonstrated generalized meningeal enhancement and normal magnetic resonance angiography while lumbar puncture revealed a cerebrospinal fluid opening pressure of less than 30 millimetres of water. Magnetic resonance myelography failed to identify the site of cerebrospinal fluid leak. The patient was managed conservatively with bed-rest, intravenous hydration, analgesics and an increased intake of oral coffee which led to a gradual relief of headaches in the upright posture.ConclusionsSpontaneous intracranial hypotension can rarely present as thunderclap headache. Awareness of its varied spectrum of presentations would avoid inappropriate investigations, misinterpretation of imaging results and ineffective treatment.

MR angiography in tuberculous meningitis

Infarctions in tuberculous meningitis (TBM) are common but there is a paucity of studies on MR angiography (MRA). To evaluate the pattern and predictors of MRA abnormality in patients with TBM. Sixty-seven patients with TBM were subjected to clinical, laboratory, magnetic resonance imaging (MRI), and MRA evaluation. The severity of meningitis, focal deficit, CSF findings, and stroke co-morbidities were recorded. Presence of exudates, infarction, hydrocephalous, and tuberculoma on MRI were noted. On intracranial MRA, occlusion or more than 50% narrowing of proximal middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA), and basilar artery were considered abnormal. The MRA abnormality was correlated with clinical, laboratory, and MRI findings. Sixty-seven patients, aged 3-75 years (median 34 years) were included. MRI was abnormal in 61 (91%) patients; basal exudates in 24, hydrocephalous in 23, tuberculoma in 33, and infarction in 40. MRA was abnormal in 34 (50.7%); MCA was most commonly involved (n = 21), followed by PCA (n = 14), ICA (n = 8), ACA (n = 5), basilar artery (n = 5), and vertebral and superior cerebellar artery (1 each). One-fourth of the patients had abnormality in both anterior and posterior circulations. MRA abnormality was related to hydrocephalous and infarction; corresponding infarct was present in 61.8% patients; 41.7% patients with abnormal MRA developed infarct at 3 months but none with normal MRA. Half the patients with TBM had MRA abnormality involving both anterior and posterior circulations and 61.8% of them had corresponding infarcts.

Idiopathic unilateral lower limb gangrene in a neonate

We are reporting a very unusual case of unilateral lower limb gangrene in 12 days neonate, who was brought to us with bluish discoloration of left foot with gangrene of toes. A negative sepsis screen, normal Doppler study, normal magnetic resonance angiography and absence of evidence of hypercoagulable state prompted us to make the diagnosis of idiopathic unilateral lower limb gangrene in this newborn. Because of the rarity we are reporting this case with vide review of literature.

Characteristics of Childhood Arterial Ischemic Stroke With Normal MR Angiography

The purposes of this study were to describe clinical and radiological characteristics of children with arterial ischemic stroke and normal MRA to compare them with children with arterial ischemic stroke and abnormal MRA. We conducted a retrospective review of clinical records and imaging. Forty children with arterial ischemic stroke and normal MRA were identified (24 male; median age, 55 months). MRA had been acquired <24 hours of symptom onset in 4, at 24 to 48 hours in 10, 48 to 96 hours in 10, 4 to 7 days in 10, and >1 week in 6 children (median, 4 days). Ten of 40 had prior diagnoses (5 cardiac, 5 malignancies). Other risk factors were identified in 30 (1 in 17 and >1 in 13; prothrombotic abnormalities in 14, prior Varicella in 7, anemia in 7, minor trauma in 4). Infarction was confined to the lenticulostriate branches of the middle cerebral artery in 21 of 40. Two patients had further clinical events, both with new infarcts; 28 patients were reimaged and MRA remained normal in all. Although similar in terms of age and gender to those with abnormal MRA, children with normal MRA were significantly more likely to have at least 1 RF (P=0.012). Those with abnormal MRA were significantly more likely to have multiple territory infarcts (P<0.001), but lesion topography was otherwise not predictive of abnormal MRA (P=0.45). Abnormal MRA was significantly associated with clinical recurrence (P<0.001). Children with arterial ischemic stroke and normal MRA are not a distinct demographic group but are more likely to have single-territory lesions and have nonvascular risk factors. The stroke mechanism in children with normal MRA remains unclear.

Investigation of childhood central nervous system vasculitis: magnetic resonance angiography versus catheter cerebral angiography

We compared the clinical utility of magnetic resonance angiography (MRA) to catheter cerebral angiography (CA) in the investigation of children with suspected central nervous system (CNS) vasculitis. Single-centre retrospective review of children with a suspected diagnosis of CNS vasculitis studied with both MRA and CA. MRA and CA-detected abnormalities (location, multiplicity, and morphology) were compared; sensitivity and specificity were calculated on a per lesion and per patient basis for MRA, with CA as the reference standard. Findings in fourteen patients (median age at presentation of 5 y 10 mo [range 1 y 5 mo-14 y 5 mo]; eight males, six females) relating to sixteen paired studies of MRA and CA were reviewed. CA-detected lesions were commonly bilateral (13/16 studies, p<0.05), and likely to be proximally distributed (15/16 studies, p<0.05).The sensitivity and specificity of MRA for CA lesion detection was 63% (95% confidence interval [CI] 48-78) and 89% (95% CI 81-93), respectively with moderate agreement between the two modalities (kappa=0.51, 95% CI 0.37-0.66). The majority of the false negative observations involved the posterior circulation (9/14). The overall sensitivity for MRA diagnosis of vasculitis per patient was 94% (95% CI 67-99). MRA failed to identify all lesions detected on CA, particularly those in the posterior circulation. MRA is a reasonable initial modality in the investigation of suspected CNS vasculitis but in cases of abnormal parenchymal MRI and normal MRA, CA should be considered.

Syndrome de vasoconstriction cérébrale réversible

Reversible cerebral vasoconstriction syndrome (RCVS) is more frequent than previously thought and is probably underdiagnosed. The mean age of onset is 42 years, and it affects slightly more women than men. RCVS is attributed to a transient, reversible dysregulation of cerebral vascular tone, which leads to multifocal arterial constriction and dilation. More than half the cases (60%) are secondary to exposure to vasoactive substances (e.g., cannabis, antidepressants, and nasal decongestants) or occur in the postpartum period. RCVS has a characteristic clinical and radiological course, developing in a single phase after a sudden onset, and there is generally no new event after 1 month. The main pattern of presentation begins with recurrent thunderclap headaches, often triggered by sexual activity or various Valsalva's maneuvers, over a period of 1 to 3 weeks. Seizures and focal neurological deficits are less frequent and generally start after the headaches. Cortical subarachnoid hemorrhage (22%), intracerebral hemorrhage (6%), seizures (3%), and reversible posterior leukoencephalopathy (9%) are early complications, occurring mainly within the first week. Ischemic events, including TIAs (16%) and cerebral infarction (4%), occur significantly later than hemorrhagic strokes, mainly during the second week. Diagnosis requires the demonstration of the characteristic "string and beads" on cerebral angiography and can be difficult, for 21% of patients have a normal initial magnetic resonance angiography (MRA) and 9% both a normal MRA and a normal transcranial Doppler. In these cases, the initial investigations must be repeated after a few days. The final diagnosis is made when a follow-up MRA shows resolution or at least marked improvement of the arterial abnormalities within 12 weeks. RCVS is sometimes associated with other large artery lesions of the head and neck, including dissections and unruptured aneurysms, especially during the postpartum period. Nimodipine is the treatment most often recommended. In our experience, it is not especially effective in severe RCVS. Relapses are possible but rare and have not yet been reported in prospective series. Although the exact pathophysiology remains speculative, strong recommendations against vasoactive substances appear prudent.

Magnetic resonance angiography versus endoscopy for the assessment of gastroesophageal varices in biliary atresia

This study was undertaken to compare magnetic resonance angiography (MRA) and gastrointestinal tract endoscopy (ENDO) for detecting varices in postoperative biliary atresia (BA) patients. Thirty-four BA patients were divided into groups according to age and liver function; group 1: 1-4 years old; group 2: 5-9 years old; group 3: over 10 years old; group A: normal liver function; and group B: moderate liver dysfunction. All subjects had MRA and ENDO. ENDO showed esophageal or gastric varices in 16 of 34 subjects. MRA depicted gastroesophageal vessels in 12 of 16 cases with varices on ENDO (sensitivity: 75%). Two subjects appeared to have varices on MRA that could not be confirmed on ENDO. Sixteen subjects had no varices on ENDO and normal MRA (specificity: 88.9%). Sensitivities and specificities of MRA for detecting varices were 20 (1/5) and 100% (6/6) in group 1 (n = 11), 100 (6/6) and 66.7% (4/6) in group 2 (n = 12), 100 (5/5) and 100% (6/6) in group 3 (n = 11), 100 (8/8) and 100% (9/9) in group A (n = 17), 50 (4/8) and 77.8% (7/9) in group B (n = 17), respectively. From these findings, MRA was not accurate in BA patients less than 10 years old or with moderate liver dysfunction. Therefore, periodic endoscopic examination is recommended for the accurate assessment and follow-up of varices in postoperative BA patients.