Publications by authors named "Dennis W W Shaw"

53 Publications

Quantitative Assessment of the Intracranial Vasculature of Infants and Adults Using iCafe (Intracranial Artery Feature Extraction).

Front Neurol 2021 28;12:668298. Epub 2021 May 28.

University of Washington, Seattle, WA, United States.

Comprehensive quantification of intracranial artery features may help to assess and understand regional variations of blood supply during early brain development and aging. We analyzed vasculature features of 27 healthy infants during natural sleep, 13 infants at 7-months (7.3 ± 1.0 month), and 14 infants at 12-months (11.7 ± 0.4 month), and 13 older healthy, awake adults (62.8 ± 8.7 years) to investigate age-related vascular differences as a preliminary study of vascular changes associated with brain development. 3D time-of-flight (TOF) magnetic resonance angiography (MRA) acquisitions were processed in iCafe, a technique to quantify arterial features (http://icafe.clatfd.cn), to characterize intracranial vasculature. Overall, adult subjects were found to have increased ACA length, tortuosity, and vasculature density compared to both 7-month-old and 12-month-old infants, as well as MCA length compared to 7-month-old infants. No brain laterality differences were observed for any vascular measures in either infant or adult age groups. Reduced skull and brain sharpness, indicative of increased head motion and brain/vascular pulsation, respectively, were observed in infants but not correlated with length, tortuosity, or vasculature density measures. Quantitative analysis of TOF MRA using iCafe may provide an objective approach for systematic study of infant brain vascular development and for clinical assessment of adult and pediatric brain vascular diseases.
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http://dx.doi.org/10.3389/fneur.2021.668298DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8193571PMC
May 2021

Focal Cerebral Arteriopathy of Childhood: Clinical and Imaging Correlates.

Stroke 2021 May 27:STROKEAHA120031880. Epub 2021 May 27.

Department of Neurology, Seattle Children's Hospital and University of Washington (M.S.W., C.A.-L.).

Background And Purpose: Focal cerebral arteriopathy (FCA) of childhood with unilateral stenosis of the anterior circulation is reported to account for up to one-quarter of childhood arterial ischemic stroke, with stroke recurrence in 25% of cases. Limited knowledge regarding pathophysiology and outcome results in inconsistent treatment of FCA.

Methods: Children with arterial ischemic stroke due to FCA between January 1, 2009, and January 1, 2019, were retrospectively identified at our institution which serves the US Pacific Northwest region. Electronic health record data, including neuroimaging studies, were reviewed, and the Pediatric Stroke Outcome Measure at 1 year was determined as the primary clinical end point.

Results: Fifteen children were diagnosed with FCA, accounting for 19% of children with cerebral arteriopathies (n=77). Among children with FCA, the median age at the time of stroke was 6.8 years (Q1-Q3, 1.9-14.0 years). Four (20%) patients had worsening stroke, 3 of whom had concurrent infection. Three (20%) FCA cases were treated with steroids, one of whom had worsening stroke. Median Pediatric Stroke Outcome Measure at 1 year was 1.0 (Q1-Q3, 0.6-2.0). Variability in arteriopathy severity was observed within many patients. Patients with more severe arteriopathy using the Focal Cerebral Arteriopathy Severity Score had larger strokes and were more likely to have worsening stroke. The most common long-term neurological deficit was hemiparesis, which was present in 11 (73%) patients and associated with middle cerebral artery arteriopathy and infarcts.

Conclusions: FCA may be less common than previously reported. Neuroimaging in FCA can help identify patients at greater risk for worsening stroke.
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http://dx.doi.org/10.1161/STROKEAHA.120.031880DOI Listing
May 2021

Gadolinium retention: should pediatric radiologists be concerned, and how to frame conversations with families.

Pediatr Radiol 2021 May 12. Epub 2021 May 12.

Department of Radiology, Seattle Children's Hospital, M/S MA.7.220, P.O. Box 5731, Seattle, WA, 98145-5005, USA.

Gadolinium retention in the brain and other organs has recently been identified by imaging and confirmed histologically. No direct clinical effects of gadolinium retention, which occurs after gadolinium-based contrast agent (GBCA) administration for MRI, have been scientifically accepted at this time. However, there is understandable concern among medical professionals and the public about the potential effects of gadolinium retention, particularly in the brain. Part of this concern might stem from the identification of nephrogenic systemic fibrosis caused by GBCAs in people with severe renal failure in 2006. This article briefly describes the characteristics of GBCAs; reviews and differentiates gadolinium retention, nephrogenic systemic fibrosis, and "gadolinium deposition disease" or "gadolinium toxicity"; and discusses societal guidelines and current usage in children. With the belief that GBCAs should not be withheld for appropriate indications in the absence of evidence of its potential risks, we offer a framework for determining when GBCA use is appropriate and suggestions for discussing its risks and benefits with children and their families.
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http://dx.doi.org/10.1007/s00247-021-04973-5DOI Listing
May 2021

Longitudinal study of MRI and functional outcome measures in facioscapulohumeral muscular dystrophy.

BMC Musculoskelet Disord 2021 Mar 10;22(1):262. Epub 2021 Mar 10.

Department of Radiology, University of Washington, Seattle, Washington, USA.

Background: Facioscapulohumeral muscular dystrophy (FSHD) is a patchy and slowly progressive disease of skeletal muscle. For MRI to be a useful biomarker in an FSHD clinical trial, it should reliably detect changes over relatively short time-intervals (~ 1 year). We hypothesized that fatty change over the study course would be most likely in muscles already demonstrating disease progression, and that the degree of MRI burden would be correlated with function.

Methods: We studied 36 patients with FSHD and lower-extremity weakness at baseline. Thirty-two patients returned in our 12-month longitudinal observational study. We analyzed DIXON MRI images of 16 lower-extremity muscles in each patient and compared them to quantitative strength measurement and ambulatory functional outcome measures.

Results: There was a small shift to higher fat fractions in the summed muscle data for each patient, however individual muscles demonstrated much larger magnitudes of change. The greatest increase in fat fraction was observed in muscles having an intermediate fat replacement at baseline, with minimally (baseline fat fraction < 0.10) or severely (> 0.70) affected muscles less likely to progress. Functional outcome measures did not demonstrate marked change over the interval; however, overall MRI disease burden was correlated with functional outcome measures. Direct comparison of the tibialis anterior (TA) fat fraction and quantitative strength measurement showed a sigmoidal relationship, with steepest drop being when the muscle gets more than ~ 20% fatty replaced.

Conclusions: Assessing MRI changes in 16 lower-extremity muscles across 1 year demonstrated that those muscles having an intermediate baseline fat fraction were more likely to progress. Ambulatory functional outcome measures are generally related to overall muscle MRI burden but remain unchanged in the short term. Quantitative strength measurement of the TA showed a steep loss of strength when more fatty infiltration is present suggesting that MRI may be preferable for following incremental change or modulation with drug therapy.
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http://dx.doi.org/10.1186/s12891-021-04134-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7948347PMC
March 2021

Deep medullary vein engorgement and superficial medullary vein engorgement: two patterns of perinatal venous stroke.

Pediatr Radiol 2021 May 22;51(5):675-685. Epub 2020 Oct 22.

Department of Radiology, University of Washington School of Medicine, Seattle Children's Hospital, 4800 Sand Point Way NE, Seattle, WA, 98105, USA.

Perinatal venous stroke has classically been attributed to cerebral sinovenous thrombosis with resultant congestion or thrombosis of the small veins draining the cerebrum. Advances in brain MRI, in particular susceptibility-weighted imaging, have enabled the visualization of the engorged small intracerebral veins, and the spectrum of perinatal venous stroke has expanded to include isolated congestion or thrombosis of the deep medullary veins and the superficial intracerebral veins. Congestion or thrombosis of the deep medullary veins or the superficial intracerebral veins can result in vasogenic edema, cytotoxic edema or hemorrhage in the territory of disrupted venous flow. Deep medullary vein engorgement and superficial medullary vein engorgement have characteristic findings on MRI and should be differentiated from neonatal hemorrhagic stroke.
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http://dx.doi.org/10.1007/s00247-020-04846-3DOI Listing
May 2021

Rapid Magnetic Resonance Imaging of the Spine in Neonates with Spinal Dysraphism.

World Neurosurg 2020 12 19;144:e648-e659. Epub 2020 Sep 19.

Department of Radiology, University of Washington School of Medicine, Seattle Children's Hospital, Seattle, Washington, USA.

Background: The use of nonsedated T2-weighted Half-Fourier Acquisition Single-shot Turbo spin Echo magnetic resonance imaging (MRI) sequences in screening for spinal cord syrinx in neonates with spinal dysraphism has not been reported in the literature. We sought to review our experience using T2-weighted Half-Fourier Acquisition Single-shot Turbo spin Echo imaging of the spine (i.e., rapid spine MRI) in nonsedated neonates for detecting spinal cord syrinx in neonates with spinal dysraphism.

Methods: We performed a retrospective search of our radiology database for neonates with spinal dysraphism who had rapid spine MRI between May 2017 and February 2020. The images were reviewed in conjunction with clinical findings and standard spine imaging, when available.

Results: Thirty studies (in 29 neonates) fulfilled our inclusion criteria. Of the 26 neonates with myelomeningocele, 5 of them (19%) had spinal cord syrinx identified on neonatal rapid spine MRI. An additional 2 patients developed syrinx by 2 years of age. Potential pitfalls identified in interpreting rapid spine MRI include motion artifacts and distinguishing a severe holocord syrinx from a truncated spinal cord.

Conclusions: Rapid spine MRI acquired without sedation or anesthesia may be used as a screening technique to detect spinal cord syrinx in neonates with spinal dysraphism.
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http://dx.doi.org/10.1016/j.wneu.2020.09.013DOI Listing
December 2020

Structural MRI and tract-based spatial statistical analysis of diffusion tensor imaging in children with hemimegalencephaly.

Neuroradiology 2020 Nov 10;62(11):1467-1474. Epub 2020 Jul 10.

Department of Radiology, Seattle Children's Hospital, University of Washington, Seattle, WA, USA.

Purpose: To investigate the gross white matter abnormalities in the structural brain MR imaging as well as white matter microstructural alterations using tract-based spatial statistics (TBSS) analysis of diffusion tensor imaging (DTI) in both affected and contralateral cerebral hemispheres of children with hemimegalencephaly (HMEG).

Methods: From 2003 to 2019, we retrospectively reviewed brain MR images in 20 children (11 boys, 2 days-16.5 years) with HMEG, focusing on gross white matter abnormalities. DTI was evaluated in 12 patients (8 boys, 3 months-16.5 years) with HMEG and 12 age-, sex-, and magnetic field strength-matched control subjects. TBSS analysis was performed to analyze main white matter tracts. Regions of significant differences in fractional anisotropy (FA) were determined between HMEG and control subjects and between affected and contralateral hemispheres of HMEG.

Results: Gross white matter abnormalities were noted in both affected (n = 20, 100%) and contralateral hemisphere (n = 4, 20%) of HMEG. FA values were significantly decreased in both hemispheres of HMEG, compared with control subjects (P < 0.05). Contralateral hemispheres of HMEG showed regions with significantly decreased FA values compared with affected hemispheres (P < 0.05).

Conclusions: In addition to gross white matter abnormalities particularly evident in affected hemispheres, DTI analysis detected widespread microstructural alterations in both affected and contralateral hemispheres in HMEG suggesting HMEG may involve broader abnormalities in neuronal networks.
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http://dx.doi.org/10.1007/s00234-020-02491-zDOI Listing
November 2020

A novel algorithm for refining cerebral vascular measurements in infants and adults.

J Neurosci Methods 2020 07 25;340:108751. Epub 2020 Apr 25.

University of Washington, Box 358050, 850 Republican St, Rm 127, Seattle, WA, 98109-4714, United States. Electronic address:

Background: Comprehensive quantification of intracranial vascular characteristics by vascular tracing provides an objective clinical assessment of vascular structure. However, weak signal or low contrast in small distal arteries, artifacts due to volitional motion, and vascular pulsation are challenges for accurate vessel tracing from 3D time-of-flight (3D-TOF) magnetic resonance angiography (MRA) images.

New Method: A vascular measurement refinement algorithm is developed and validated for robust quantification of intracranial vasculature from 3D-TOF MRA. After automated vascular tracing, centerline positions, lumen radii and centerline deviations are jointly optimized to restrict traces to within vascular regions in the straightened curved planar reformation (CPR) views. The algorithm is validated on simulated vascular images and on repeat 3D-TOF MRA acquired from infants and adults.

Results: The refinement algorithm can reliably estimate vascular radius and correct deviated centerlines. For the simulated vascular image with noise level of 1 and deviation of centerline of 3, the mean radius difference is below 15.3 % for scan-rescan reliability. Vascular features from repeated clinical scans show significantly improved measurement agreement, with intra-class correlation coefficient (ICC) improvement from 0.55 to 0.7 for infants and from 0.59 to 0.92 for adults.

Comparison With Existing Methods: The refinement algorithm is novel because it utilizes straightened CPR views that incorporate information from the entire artery. In addition, the optimization corrects centerline positions, lumen radii and centerline deviations simultaneously.

Conclusions: Intracranial vasculature quantification using a novel refinement algorithm for vascular tracing improves the reliability of vascular feature measurements in both infants and adults.
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http://dx.doi.org/10.1016/j.jneumeth.2020.108751DOI Listing
July 2020

Magnetic resonance imaging correlates with electrical impedance myography in facioscapulohumeral muscular dystrophy.

Muscle Nerve 2020 05 22;61(5):644-649. Epub 2020 Jan 22.

Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas.

Introduction: Electrical impedance myography (EIM) has been proposed as a noninvasive biomarker of muscle composition in facioscapulohumeral muscular dystrophy (FSHD). Here we determine the associations of EIM variables with muscle structure measured by MRI.

Methods: We evaluated 20 patients with FSHD at two centers, comparing EIM measurements (resistance, reactance, and phase at 50, 100, and 211 kHZ) recorded from bilateral vastus lateralis, tibialis anterior, and medial gastrocnemius muscles to MRI skin and subcutaneous fat thickness, MRI T1-based muscle severity score (T1 muscle score), and MRI quantitative intramuscular Dixon fat fraction (FF).

Results: While reactance and phase both correlated with FF and T1 muscle score, 50 kHz reactance was most sensitive to muscle structure alterations measured by both T1 score (ρ = -0.71, P < .001) and FF (ρ = -0.74, P < .001).

Discussion: This study establishes the correlation of EIM with structural MRI features in FSHD and supports further evaluation of EIM as a potential biomarker in FSHD clinical trials.
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http://dx.doi.org/10.1002/mus.26792DOI Listing
May 2020

Risk of Intracranial Hemorrhage Following Intravenous tPA (Tissue-Type Plasminogen Activator) for Acute Stroke Is Low in Children.

Stroke 2020 02 17;51(2):542-548. Epub 2019 Dec 17.

Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia (R.N.I.).

Background and Purpose- Data regarding the safety and efficacy of intravenous tPA (tissue-type plasminogen activator) in childhood acute arterial ischemic stroke are inadequate. The TIPS trial (Thrombolysis in Pediatric Stroke; National Institutes of Health grant R01NS065848)-a prospective safety and dose-finding trial of intravenous tPA in acute childhood stroke-was closed for lack of accrual. TIPS sites have subsequently treated children with acute stroke in accordance with established institutional protocols supporting data collection on outcomes. Methods- Data on children treated with intravenous tPA for neuroimaging-confirmed arterial ischemic stroke were collected retrospectively from 16 former TIPS sites to establish preliminary safety data. Participating sites were required to report all children who were treated with intravenous tPA to minimize reporting bias. Symptomatic intracranial hemorrhage (SICH) was defined as ECASS (European Cooperative Acute Stroke Study) II parenchymal hematoma type 2 or any intracranial hemorrhage associated with neurological deterioration within 36 following tPA administration. A Bayesian beta-binomial model for risk of SICH following intravenous tPA was fit using a prior distribution based on the risk level in young adults (1.7%); to test for robustness, the model was also fit with uninformative and conservative priors. Results- Twenty-six children (age range, 1.1-17 years; median, 14 years; 12 boys) with stroke and a median pediatric National Institutes of Health Stroke Scale score of 14 were treated with intravenous tPA within 2 to 4.5 hours (median, 3.0 hours) after stroke onset. No patient had SICH. Two children developed epistaxis. Conclusions- The estimated risk of SICH after tPA in children is 2.1% (95% highest posterior density interval, 0.0%-6.7%; mode, 0.9%). Regardless of prior assumption, there is at least a 98% chance that the risk is <15% and at least a 93% chance that the risk is <10%. These results suggest that the overall risk of SICH after intravenous tPA in children with acute arterial ischemic stroke, when given within 4.5 hours after symptom onset, is low.
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http://dx.doi.org/10.1161/STROKEAHA.119.027225DOI Listing
February 2020

An update on the use of an arterial closure device following femoral arterial puncture in children.

Pediatr Radiol 2019 08 12;49(9):1217-1221. Epub 2019 Jun 12.

Department of Radiology, Section of Interventional Radiology, Seattle Children's Hospital, University of Washington, 4800 Sand Point Way NE, Seattle, WA, 98105, USA.

Background: The use of arterial closure devices in achieving femoral hemostasis has been well documented in adults but insufficiently studied in the pediatric population. An earlier study from our institution of 40 Angio-Seal devices in 38 patients concluded that the arterial closure device is safe in children with only a single minor complication. Ongoing experience with this device at our institution, however, suggests a higher rate of complication.

Objective: To retrospectively evaluate the safety and efficacy of the Angio-Seal in a pediatric population.

Materials And Methods: A retrospective analysis reviewed all cases in which the Angio-Seal was deployed from June 2011 to September 2017. Peri-procedural documentation was reviewed for pre-procedure labs, clinical effectiveness in achieving hemostasis and complications related to the use of this device. Logistic regression analysis was also used to evaluate the relationship between patient demographic, vessel size and indication for angiography, and the presence or absence of complications.

Results: During the study period, 48 additional Angio-Seal devices were deployed in 41 consecutive patients. Five patients were excluded for being older than 18 years. The mean age of the patients was 13.3 years (range: 4-18 years) with 18 patients female. The mean common femoral artery diameter was 5.98 mm in short axis diameter (range: 4-9 mm). Complications were present in 6/43 cases (14%) including 3 minor and 3 major complications that included additional procedures. No significant relationship was identified between vessel size, age and the indication for angiography, and the rate of complication on logistic regression analysis.

Conclusion: While percutaneous arterial closure devices can be efficacious for achieving hemostasis, our experience demonstrates a higher rate of complications in children, contrary to a previous report. The deployment of such devices should be performed with prejudice in this population.
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http://dx.doi.org/10.1007/s00247-019-04442-0DOI Listing
August 2019

Conformal Radiation Therapy for Pediatric Patients with Low-Grade Glioma: Results from the Children's Oncology Group Phase 2 Study ACNS0221.

Int J Radiat Oncol Biol Phys 2019 03 10;103(4):861-868. Epub 2018 Nov 10.

Department of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee. Electronic address:

Purpose: To determine the rate of marginal relapse, progression-free survival (PFS), and overall survival (OS) in patients with pediatric low-grade glioma (PLGG) treated with conformal radiation therapy (CRT) with a clinical target volume (CTV) margin of 5 mm in the Children's Oncology Group trial ACNS0221.

Methods And Materials: Patients aged 3 to 21 years with unresectable progressive, recurrent, or residual PLGG were eligible for this study. Patients younger than 10 years were required to have received at least 1 chemotherapy course. Patients with neurofibromatosis type I were not eligible. All patients underwent magnetic resonance imaging-based planning and received 54 Gy CRT in 30 fractions with a 5-mm CTV margin.

Results: Of 85 eligible patients (median age, 13.6 years) treated between March 2006 and December 2010, 14 were younger than 10 years and 36 received prior chemotherapy. Sixty-six had pilocytic astrocytoma, 15 had other histologic subtypes, and 4 had unbiopsied chiasmatic lesions. Events included 23 relapses (19 central, 4 distant, and no marginal) and 7 deaths. At a median follow-up of 5.15 years, 5-year PFS was 71% ± 6% and OS was 93% ± 4%. Male sex (P = .068) and large tumor size (P = .050) trended toward significance for association with decreased PFS. Age, histology, tumor location, time between diagnosis and study entry, and MIB-1 status were not associated with PFS. OS was negatively associated with male sex (P = .064), non-pilocytic astrocytoma histology (P = .010), and large tumor size (P = .0089).

Conclusions: For patients with PLGG, CRT with a CTV margin of 5 mm yields an acceptable PFS and does not lead to a high rate of marginal relapse.
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http://dx.doi.org/10.1016/j.ijrobp.2018.11.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6548322PMC
March 2019

Catheter-Directed Thrombolysis for Portal Vein Thrombosis in Children: A Case Series.

J Vasc Interv Radiol 2018 11 17;29(11):1578-1583. Epub 2018 Sep 17.

Section of Interventional Radiology, Department of Radiology, Seattle Children's Hospital, 4800 Sand Point Way NE, Seattle, WA 98105; Department of Radiology, University of Washington, Seattle, Washington.

Purpose: To describe safety and efficacy of catheter-directed thrombolysis (CDT) for portal vein thrombosis (PVT) in children.

Materials And Methods: Retrospective review was performed of 10 consecutive patients (7 girls, 3 boys; mean age 11.9 y; range, 3-17 y) with PVT undergoing CDT at a single tertiary children's hospital between August 2005 and March 2016. PVT was categorized by etiology and extent (intrahepatic, extrahepatic, or both). CDT was performed with infusion catheters placed via percutaneous transhepatic (PTH) and/or transjugular intrahepatic (TJ) approaches, with or without the use of adjunctive maneuvers, including balloon maceration and suction and rheolytic thrombectomy. Degree of thrombolysis on portal venography, presence of portal vein thrombus on available follow-up imaging, and complication rates were recorded.

Results: In 10 patients, 13 CDT procedures were performed for PVT, with 3 patients requiring repeat CDT. Portal access was achieved with PTH (n = 6), TJ (n = 2), or combined (n = 2) approaches. All cases were successful in re-establishing patency and hepatopetal flow on portal venography with complete thrombolysis achieved in 10 of 13 cases (77%). Two major complications (20%) occurred, both with PTH access. Mean follow-up time for 9 patients was 2.6 years (range, 51-1,902 d) with long-term patency achieved in 6 (67%).

Conclusions: CDT can be safe and effective for PVT in children. Portal access considerations and early initiation of thrombolysis may further increase safety and efficacy.
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http://dx.doi.org/10.1016/j.jvir.2018.07.018DOI Listing
November 2018

Surveillance magnetic resonance imaging for isolated optic pathway gliomas: is gadolinium necessary?

Pediatr Radiol 2018 09 22;48(10):1472-1484. Epub 2018 May 22.

Department of Radiology,, University of Washington,, Seattle, WA, USA.

Background: Pediatric optic pathway gliomas are typically indolent but have a variable clinical course. Treatment is dictated by symptoms and changes on contrast-enhanced MRI examinations. Gadolinium retention in children has motivated parsimonious use of gadolinium-based contrast agents.

Objectives: To determine surveillance MR factors that motivate changes in tumor-directed therapies and extrapolate cost-efficacy of a non-contrast follow-up protocol.

Materials And Methods: Using an imaging database search we identified children with isolated optic pathway gliomas and ≥3 follow-up contrast-enhanced MRIs. We reviewed medical records and imaging for: (1) coincident changes on contrast-enhanced MRI and tumor-directed therapy, (2) demographics and duration of follow-up, (3) motivations for intervention, (4) assessment of gadolinium-based contrast agents' utility and (5) health care utilization data. We assessed cost impact in terms of relative value unit (RVU) burden.

Results: We included 17 neurofibromatosis type 1 (NF1) and 21 non-NF1 patients who underwent a median 16.9 and 24.3 cumulative contrast-enhanced MR exams over 7.7 years and 8.1 years of follow-up, respectively. Eight children (one with NF1) had intervention based on contrast-enhanced MR findings alone. For these eight, increased tumor size was the only common feature, and it was apparent on non-contrast T2 sequences. For the median patient, a non-contrast follow-up protocol could result in 15.9 (NF1) and 23.3 (non-NF1) fewer gadolinium-based contrast agent administrations, and a 39% lower yearly RVU burden.

Conclusion: Pediatric patients with isolated optic pathway gliomas undergo a large number of routine contrast-enhanced MR follow-up exams. Gadolinium might not be needed for these exams to inform management decisions. Secondary benefits of a non-contrast follow-up protocol include decreased cost and risk to the patient.
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http://dx.doi.org/10.1007/s00247-018-4154-4DOI Listing
September 2018

Congenital Zika virus infection as a silent pathology with loss of neurogenic output in the fetal brain.

Nat Med 2018 03 5;24(3):368-374. Epub 2018 Feb 5.

Washington National Primate Research Center, Seattle, Washington, USA.

Zika virus (ZIKV) is a flavivirus with teratogenic effects on fetal brain, but the spectrum of ZIKV-induced brain injury is unknown, particularly when ultrasound imaging is normal. In a pregnant pigtail macaque (Macaca nemestrina) model of ZIKV infection, we demonstrate that ZIKV-induced injury to fetal brain is substantial, even in the absence of microcephaly, and may be challenging to detect in a clinical setting. A common and subtle injury pattern was identified, including (i) periventricular T2-hyperintense foci and loss of fetal noncortical brain volume, (ii) injury to the ependymal epithelium with underlying gliosis and (iii) loss of late fetal neuronal progenitor cells in the subventricular zone (temporal cortex) and subgranular zone (dentate gyrus, hippocampus) with dysmorphic granule neuron patterning. Attenuation of fetal neurogenic output demonstrates potentially considerable teratogenic effects of congenital ZIKV infection even without microcephaly. Our findings suggest that all children exposed to ZIKV in utero should receive long-term monitoring for neurocognitive deficits, regardless of head size at birth.
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http://dx.doi.org/10.1038/nm.4485DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5839998PMC
March 2018

Ultrasound-guided lumbar puncture in pediatric patients: technical success and safety.

Pediatr Radiol 2018 06 3;48(6):875-881. Epub 2018 Feb 3.

Department of Radiology, Section of Interventional Radiology, Seattle Children's Hospital, University of Washington, 4800 Sand Point Way NE, M/S R-5417, Seattle, WA, 98105, USA.

Background: Disadvantages of fluoroscopically guided lumbar puncture include delivery of ionizing radiation and limited resolution of incompletely ossified posterior elements. Ultrasound (US) allows visualization of critical soft tissues and the cerebrospinal fluid (CSF) space without ionizing radiation.

Objective: To determine the technical success and safety of US-guided lumbar puncture in pediatric patients.

Materials And Methods: A retrospective review identified all patients referred to interventional radiology for lumbar puncture between June 2010 and June 2017. Patients who underwent lumbar puncture with fluoroscopic guidance alone were excluded. For the remaining procedures, technical success and procedural complications were assessed. Two hundred and one image-guided lumbar punctures in 161 patients were included. Eighty patients (43%) had previously failed landmark-based attempts.

Results: One hundred ninety-six (97.5%) patients underwent lumbar puncture. Five procedures (2.5%) were not attempted after US assessment, either due to a paucity of CSF or unsafe window for needle placement. Technical success was achieved in 187 (95.4%) of lumbar punctures attempted with US guidance. One hundred seventy-seven (90.3%) were technically successful with US alone (age range: 2 days-15 years, weight range: 1.9-53.1 kg) and an additional 10 (5.1%) were successful with US-guided thecal access and subsequent fluoroscopic confirmation. Three (1.5%) cases were unsuccessful with US guidance but were subsequently successful with fluoroscopic guidance. Of the 80 previously failed landmark-based lumbar punctures, 77 (96.3%) were successful with US guidance alone. There were no reported complications.

Conclusion: US guidance is safe and effective for lumbar punctures and has specific advantages over fluoroscopy in pediatric patients.
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http://dx.doi.org/10.1007/s00247-018-4091-2DOI Listing
June 2018

MRI change metrics of facioscapulohumeral muscular dystrophy: Stir and T1.

Muscle Nerve 2018 06 3;57(6):905-912. Epub 2018 Mar 3.

Department of Radiology, Seattle Children's Hospital, 4800 Sandpoint Way, Room: L-MA.6.226, Seattle, Washington, 98105, USA.

Introduction: MRI evaluation in facioscapulohumeral muscular dystrophy (FSHD) demonstrates fatty replacement and inflammation/edema in muscle. Our previous work demonstrated short T1 inversion recovery (STIR)-hyperintense (STIR+) signal in muscle 2 years before fatty replacement. We evaluated leg muscle STIR changes and fatty replacement within 14 months.

Methods: FSHD subjects received 2 MRI scans of thigh and calf over a 6.9- to 13.8-month interval. Quality of life measures were collected. One Radiologist rated muscle changes on a semi-quantitative scale.

Results: Fifteen subjects completed longitudinal imaging. Four STIR + muscles and 3 STIR-normal (STIR-) muscles were rated as progressing to fatty tissue over the study period.

Discussion: STIR + muscles with confluent regions of fat at baseline increased more in fat, while STIR- muscles had increases in septal-fat over the study period. These changes may reflect two phases of FSHD, demonstrating MRI sensitivity is weighted toward gross pathological phases of the disease. Muscle Nerve 57: 905-912, 2018.
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http://dx.doi.org/10.1002/mus.26038DOI Listing
June 2018

Transforaminal intrathecal delivery of nusinersen using cone-beam computed tomography for children with spinal muscular atrophy and extensive surgical instrumentation: early results of technical success and safety.

Pediatr Radiol 2018 03 13;48(3):392-397. Epub 2017 Nov 13.

Department of Radiology, Section of Interventional Radiology, Seattle Children's Hospital, University of Washington, 4800 Sand Point Way NE, M/S R-5417, Seattle, WA, 98105, USA.

Background: Nusinersen, the only treatment approved by the United States Food and Drug Administration for spinal muscular atrophy (SMA), is delivered intrathecally. Many children with SMA have extensive spinal instrumentation and deformities, often precluding the use of standard approaches for gaining intrathecal access. Furthermore the anatomical distortion that often occurs with rotoscoliosis can complicate the use of fluoroscopic guidance. Compared to fluoroscopy, CT affords superior guidance for complex needle placements. This opens up alternatives to the posterior (interlaminar) technique, including transforaminal and caudal approaches.

Objective: This study describes the early results of technical success, complications and radiation dose of intrathecal delivery of nusinersen using cone-beam CT guidance with two-axis fluoroscopic navigational overlay.

Materials And Methods: We conducted a retrospective review of 15 consecutive nusinersen injections performed in four children with SMA and extensive spinal hardware precluding standard posterior lumbar puncture techniques. These children were treated using transforaminal thecal access employing cone-beam CT with navigational overlay. We analyzed results including technical success, complications and total fluoroscopy time.

Results: All procedures were technically successful. No major complications and one minor complication were reported; the minor complication was a post-procedural neuropathic headache that was attributed to procedural positioning and was treated successfully with gabapentin. The average procedural fluoroscopy time and air kerma were 1.9 min and 55.8 mGy, respectively.

Conclusion: Cone-beam CT guidance with two-axis navigational overlay is a safe, effective method for gaining transforaminal intrathecal access in children with spinal abnormalities and hardware precluding the use of standard techniques.
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http://dx.doi.org/10.1007/s00247-017-4031-6DOI Listing
March 2018

GABA alterations in pediatric sport concussion.

Neurology 2017 Nov 13;89(21):2151-2156. Epub 2017 Oct 13.

From the Seattle Children's Hospital and Research Institute (S.D.F., A.V.P., C.B., D.W.W.S., D.B., T.J., B.K., D.C, T.M.L., S.B., J.G.O.) and University of Washington (D.W.W.S., D.B., T.J., B.K., D.C., S.B., J.G.O.), Seattle.

Objective: To evaluate whether frontal-lobe magnetic resonance spectroscopy measures of γ-aminobutyric acid (GABA) would be altered in a sample of adolescents scanned after sport concussion because mild traumatic brain injury is often associated with working memory problems.

Methods: Eleven adolescents (age 14-17 years) who had sustained a first-time sport concussion were studied with MRI/magnetic resonance spectroscopy within 23 to 44 days after injury (mean 30.4 ± 6.1 days). Age- and sex-matched healthy controls, being seen for sports-related injuries not involving the head and with no history of concussion, were also examined. GABA/creatine + phosphocreatine (Cre) was measured in left-sided frontal lobe and central posterior cingulate regions. The frontal voxel was positioned to overlap with patient-specific activation on a 1-back working memory task.

Results: Increased GABA/Cre was shown in the frontal lobe for the concussed group. A decreased relationship was observed in the parietal region. High correlations between GABA/Cre and task activation were observed for the control group in the frontal lobe, a relationship not shown in the concussed participants.

Conclusions: GABA/Cre appears increased in a region colocalized with working memory task activation after sport concussion. Further work extending these results in larger samples and at time points across the injury episode will aid in refining the clinical significance of these observations.
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http://dx.doi.org/10.1212/WNL.0000000000004666DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5696637PMC
November 2017

Cerebral palsy and seizures in a child with tubulinopathy pattern dysgenesis and focal cortical dysplasia.

Radiol Case Rep 2017 Jun 30;12(2):396-400. Epub 2017 Jan 30.

Department of Radiology, Seattle Children's Hospital, Mail Stop MA.07.220, 4800 Sand Point Way NE, Seattle, WA 98105, USA.

A 7-year-old boy with a history of spasticity, global developmental delay, and seizures was given the general diagnosis of cerebral palsy at an early age. Chromosomal array analysis performed at an outside center was normal. The patient's family sought neurodevelopmental pediatric care at a new institution following a move out of state. Electroencephalography confirmed abnormal epileptogenic activity. Brain magnetic resonance imaging showed findings consistent with a tubulin gene defect (tubulinopathy) and of focal cortical dysplasia, as well as evidence of a remote occipital lobe injury. This case report describes the various brain magnetic resonance findings suggestive of a tubulin gene defect and raises the possibility of focal cortical dysplasia manifesting as a result of tubulin dysfunction.
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http://dx.doi.org/10.1016/j.radcr.2016.12.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5417618PMC
June 2017

Fetal brain lesions after subcutaneous inoculation of Zika virus in a pregnant nonhuman primate.

Nat Med 2016 11 12;22(11):1256-1259. Epub 2016 Sep 12.

Department of Pediatrics, University of Washington, Seattle, Washington, USA.

We describe the development of fetal brain lesions after Zika virus (ZIKV) inoculation in a pregnant pigtail macaque. Periventricular lesions developed within 10 d and evolved asymmetrically in the occipital-parietal lobes. Fetal autopsy revealed ZIKV in the brain and significant cerebral white matter hypoplasia, periventricular white matter gliosis, and axonal and ependymal injury. Our observation of ZIKV-associated fetal brain lesions in a nonhuman primate provides a model for therapeutic evaluation.
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http://dx.doi.org/10.1038/nm.4193DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5365281PMC
November 2016

Assessment of diffusion tensor image quality across sites and vendors using the American College of Radiology head phantom.

J Appl Clin Med Phys 2016 05 8;17(3):442-451. Epub 2016 May 8.

Children's Medical Center Dallas; University of Texas Southwestern Medical Center Dallas.

The purpose of this study was to explore the feasibility of assessing quality of diffusion tensor imaging (DTI) from multiple sites and vendors using American College of Radiology (ACR) phantom. Participating sites (Siemens (n = 2), GE (n= 2), and Philips (n = 4)) reached consensus on parameters for DTI and used the widely available ACR phantom. Tensor data were processed at one site. B0 and eddy current distortions were assessed using grid line displacement on phantom Slice 5; signal-to-noise ratio (SNR) was measured at the center and periphery of the b = 0 image; fractional anisotropy (FA) and mean diffusivity (MD) were assessed using phantom Slice 7. Variations of acquisition parameters and deviations from specified sequence parameters were recorded. Nonlinear grid line distortion was higher with linear shimming and could be corrected using the 2nd order shimming. Following image registration, eddy current distortion was consistently smaller than acquisi-tion voxel size. SNR was consistently higher in the image periphery than center by a factor of 1.3-2.0. ROI-based FA ranged from 0.007 to 0.024. ROI-based MD ranged from 1.90 × 10-3 to 2.33 × 10-3 mm2/s (median = 2.04 × 10-3 mm2/s). Two sites had image void artifacts. The ACR phantom can be used to compare key qual-ity measures of diffusion images acquired from multiple vendors at multiple sites.
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http://dx.doi.org/10.1120/jacmp.v17i3.5972DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5690920PMC
May 2016

Corpus Callosum Diffusion and Connectivity Features in High Functioning Subjects With Pyridoxine-Dependent Epilepsy.

Pediatr Neurol 2016 Jan 25;54:43-8. Epub 2015 Sep 25.

Departments of Neurology and Pediatrics, University of Washington, Division of Neurology, Seattle Children's Hospital, Seattle Washington. Electronic address:

Background: In this observational study, white matter structure, functional magnetic resonance imaging (fMRI) task-based responses, and functional connectivity were assessed in four subjects with high functioning pyridoxine-dependent epilepsy and age-matched control subjects.

Methods: Four male subjects with pyridoxine-dependent epilepsy (mean age 31 years 8 months, standard deviation 12 years 3 months) and age-matched control subjects (32 years 4 months, standard deviation 13 years) were recruited to participate in the study. Diffusion tensor data were collected and postprocessed in Functional Magnetic Resonance Imaging of the Brain Software Library to quantify corpus callosum tracts as a means to assess white matter structure. Task-based fMRI data were collected and Functional Magnetic Resonance Imaging of the Brain Software Library used to assess task response. The fMRI resting-state data were analyzed with the functional connectivity toolbox Conn to determine functional connectivity.

Results: Subjects with high functioning pyridoxine-dependent epilepsy retained structural white matter connectivity compared with control subjects, despite morphologic differences in the posterior corpus callosum. fMRI task-based results did not differ between subjects with pyridoxine-dependent epilepsy and control subjects; functional connectivity as measured with resting-state fMRI was lower in subjects with pyridoxine-dependent epilepsy for several systems (memory, somatosensory, auditory).

Conclusion: Although corpus callosum morphology is diminished in the posterior portions, structural connectivity was retained in subjects with pyridoxine-dependent epilepsy, while functional connectivity was diminished for memory, somatosensory, and auditory systems.
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http://dx.doi.org/10.1016/j.pediatrneurol.2015.09.012DOI Listing
January 2016

Brain lactate as a potential biomarker for comorbid anxiety disorder in autism spectrum disorder.

JAMA Psychiatry 2015 Feb;72(2):190

Department of Radiology, University of Washington, Seattle3Seattle Children's Hospital, Seattle, Washington.

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http://dx.doi.org/10.1001/jamapsychiatry.2014.2419DOI Listing
February 2015

Pediatric liver transplant portal vein anastomotic stenosis: correlation between ultrasound and transhepatic portal venography.

Liver Transpl 2015 Apr 12;21(4):547-53. Epub 2015 Mar 12.

Divisions of Interventional Radiology, Division of Gastroenterology and Hepatology, Seattle Children's Hospital, University of Washington, Seattle, WA.

The objective of this study was to determine which transabdominal ultrasound parameters correlate with portal vein stenosis (PVS) on percutaneous transhepatic portal venography in pediatric liver transplant patients. A retrospective review was performed of percutaneous transhepatic portal venograms performed between 2005 and 2013. The findings were compared to those from ultrasounds performed before venography and at the baseline. Patients were stratified on the basis of the presence of significant PVS (group 1, >50% stenosis; group 2, ≤50% stenosis) on portal venography. Findings were compared to those for age-matched controls. Twenty portal venograms were performed for 12 pediatric patients. Thirteen of the 20 patients (65%) demonstrated significant PVS (>50%). The mean peak anastomotic velocity (PAV) was 253.6±96 cm/s in group 1, 169.7±48 cm/s in group 2, and 51.3±20 cm/s in the control group. PAV (r=0.672, P=0.002) was the only ultrasound variable that correlated with the presence of significant PVS. A receiver operating characteristic curve was generated from PAV and PVS data (area under the curve=0.75, P=0.08). A threshold velocity of 180 cm/s led to a sensitivity of 83% and a specificity of 71% in predicting significant PVS on portal venography. At the baseline, the mean PAV was 155.8±90 cm/s for group 1 and 69.5±33 cm/s for group 2 (P=0.08); for control subjects, it was 78.9±53 cm/s (P=0.06). PAV is the only measured ultrasound parameter that correlates with significant PVS on portal venography in pediatric liver transplant patients. An elevated baseline PAV may increase the risk of developing PVS.
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http://dx.doi.org/10.1002/lt.24077DOI Listing
April 2015

Transcranial Doppler-based assessment of cerebral autoregulation in critically ill children during diabetic ketoacidosis treatment.

Pediatr Crit Care Med 2014 Oct;15(8):742-9

1Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA. 2Department of Pediatrics, University of Washington, Seattle, WA. 3Seattle Children's Hospital, Seattle, WA. 4Department of Radiology, University of Washington, Seattle, WA.

Objectives: Impaired cerebral autoregulation may be associated with poor outcome in diabetic ketoacidosis. We examined change in cerebral autoregulation during diabetic ketoacidosis treatment.

Design: Prospective observational cohort study.

Setting: Tertiary care children's hospital.

Patients/subjects: Children admitted to the ICU with diabetic ketoacidosis (venous pH < 7.3, glucose > 300 mg/dL, HCO3 < 15 mEq/L, and ketonuria) constituted cases, and children with type I diabetes without diabetic ketoacidosis constituted controls.

Interventions: None.

Measurements And Main Results: Between 2005 and 2009, 32 cases and 50 controls were enrolled. Transcranial Doppler ultrasonography was used to measure middle cerebral artery flow velocities, and cerebral autoregulation testing was achieved via tilt-table testing. Cases underwent two and controls underwent one cerebral autoregulation test. Cerebral autoregulation was quantified by the autoregulatory index (autoregulatory index < 0.4 = impaired and autoregulatory index 0.4-1.0 = intact autoregulation). The first autoregulation test was obtained early (time 1, 12-24 hr; median [interquartile range], 8 hr [5-18 hr]) during diabetic ketoacidosis treatment, and a second autoregulation test was obtained during recovery (time 2, 36-72 hr; median [ interquartile range], 46 hr [40-59 hr]) from time 0 (defined as time of insulin start). Cases had lower autoregulatory index at time 1 than time 2 (p < 0.001) as well lower autoregulatory index than control subjects (p < 0.001). Cerebral autoregulation was impaired in 40% (n = 13) of cases at time 1 and in 6% (n = 2) of cases at time 2. Five cases (17%) showed persistent impairment of cerebral autoregulation between times 1 and 2 of treatment. All control subjects had intact cerebral autoregulation.

Conclusions: Impaired cerebral autoregulation was common early during diabetic ketoacidosis treatment. Although the majority improved during diabetic ketoacidosis treatment, 17% of subjects had impairment between 36 and 72 hours after start of insulin therapy. The observed impaired cerebral autoregulation appears specific to the diabetic ketoacidosis process in patients with type I diabetes.
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http://dx.doi.org/10.1097/PCC.0000000000000197DOI Listing
October 2014

Callosal alterations in pyridoxine-dependent epilepsy.

Dev Med Child Neurol 2014 Nov 18;56(11):1106-10. Epub 2014 Jun 18.

Department of Radiology, Seattle Children's Hospital, Seattle, WA, USA.

Aim: While there have been isolated reports of callosal morphology differences in pyridoxine-dependent epilepsy (PDE), a rare autosomal disorder caused by ALDH7A1 gene mutations, no study has systematically evaluated callosal features in a large sample of patients. This study sought to overcome this knowledge gap.

Method: Spanning a wide age range from birth to 48 years, corpus callosum morphology and cross-sectional cerebral area were measured in 30 individuals with PDE (12 males, 18 females, median age 3.92y; 25th centile 0.27, 75th centile 15.25) compared to 30 age-matched comparison individuals (11 males, 19 females, median age 3.85y; 25th centile 0.26, 75th centile 16.00). Individuals with PDE were also divided into age groups to evaluate findings across development. As delay to treatment may modulate clinical severity, groups were stratified by treatment delay (less than or greater than 2wks from birth).

Results: Markedly reduced callosal area expressed as a ratio of mid-sagittal cerebral area was observed for the entire group with PDE (p<0.001). Stratifying by age (<1y, 1-10y, >10y) demonstrated posterior abnormalities to be a consistent feature, with anterior regions increasingly involved across the developmental trajectory. Splitting the PDE group by treatment lag did not reveal overall or sub-region callosal differences.

Interpretation: Callosal abnormalities are a common feature of PDE not explained by treatment lag. Future work utilizing tract-based approaches to understand inter- and intra-hemispheric connectivity patterns will help in the better understanding the structural aspects of this disease.
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http://dx.doi.org/10.1111/dmcn.12511DOI Listing
November 2014

Atypical developmental patterns of brain chemistry in children with autism spectrum disorder.

JAMA Psychiatry 2013 Sep;70(9):964-74

Importance: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with symptoms emerging during early childhood. The pathophysiology underlying the disorder remains incompletely understood.

Objective: To examine cross-sectional and longitudinal patterns of brain chemical concentrations in children with ASD or idiopathic developmental delay (DD) from 3 different age points, beginning early in the clinical course.

Design: Proton magnetic resonance spectroscopic imaging data were acquired longitudinally for children with ASD or DD, and primarily cross-sectionally for children with typical development (TD), at 3 to 4, 6 to 7, and 9 to 10 years of age.

Setting: Recruitment, diagnostic assessments, and magnetic resonance imaging were performed at the University of Washington in Seattle.

Participants: Seventy-three children (45 with ASD, 14 with DD, and 14 with TD) at 3 to 4 years of age; 69 children (35 with ASD, 14 with DD, and 20 with TD) at 6 to 7 years of age; and 77 children (29 with ASD, 15 with DD, and 33 with TD) at 9 to 10 years of age.

Main Outcomes And Measures: Concentrations of N-acetylaspartate (NAA), choline (Cho), creatine (Cr), myo-inositol (mI), and glutamine plus glutamate (Glx) in cerebral gray matter (GM) and white matter (WM) at 3 to 4, 6 to 7, and 9 to 10 years of age, and calculation of rates of change of these chemicals between 3 and 10 years of age.

Results: At 3 to 4 years of age, the ASD group exhibited lower NAA, Cho, and Cr concentrations than did the TD group in both GM and WM, alterations that largely were not observed at 9 to 10 years of age. The DD group exhibited reduced GM and WM NAA concentrations at 3 to 4 years of age; GM NAA concentrations remained reduced at 9 to 10 years of age compared with the TD group. There were distinct differences between the ASD and DD groups in the rates of GM NAA, Cho, and Cr changes between 3 and 10 years of age.

Conclusions And Relevance: The GM chemical changes between 3 and 10 years of age differentiated the children with ASD from those with DD. Most notably, a dynamic reversal of GM NAA reductions was observed in the children with ASD. By contrast, persistent GM NAA reductions in the children with DD suggest a different, more static, underlying developmental process.
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http://dx.doi.org/10.1001/jamapsychiatry.2013.1388DOI Listing
September 2013

Longitudinal features of STIR bright signal in FSHD.

Muscle Nerve 2014 Feb;49(2):257-60

Introduction: Magnetic resonance imaging of muscle shows short tau-inversion recovery (STIR) brightness in autosomal dominant facioscapulohumeral muscular dystrophy (FSHD1) suggestive of active inflammation/injury. We measured the longitudinal stability/progression of this potential disease biomarker.

Methods: Nine subjects underwent calf MRI imaging over 2 years. Two radiologists evaluated qualitative muscle changes.

Results: In 3/9 subjects, calf muscles demonstrated moderate/severe STIR hyperintensity at Time 1 that had progressed to fatty replacement 2 years later (Time 2). In the remaining subjects, moderate/severe muscle STIR abnormalities, when present, were consistent between exams. Mild STIR+ elevations had roughly similar patterns between exams.

Conclusions: Moderate/severe STIR hyperintensities often foreshadow fatty replacement over a 2-year interval. Whether longer time courses are required to observe muscle degeneration and fatty replacement in some subjects remains to be explored.
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http://dx.doi.org/10.1002/mus.23911DOI Listing
February 2014

Brain volume findings in 6-month-old infants at high familial risk for autism.

Am J Psychiatry 2012 Jun;169(6):601-8

Carolina Institute for Developmental Disabilities and the Department of Psychiatry, University of North Carolina, Chapel Hill, USA.

Objective: Individuals with autism as young as 2 years have been observed to have larger brains than healthy comparison subjects. Studies using head circumference suggest that brain enlargement is a postnatal event that occurs around the latter part of the first year. To the authors' knowledge, no previous brain imaging studies have systematically examined the period prior to age 2. In this study they used magnetic resonance imaging (MRI) to measure brain volume in 6-month-olds at high familial risk for autism.

Method: The Infant Brain Imaging Study (IBIS) is a longitudinal imaging study of infants at high risk for autism. This cross-sectional analysis compared brain volumes at 6 months of age in high-risk infants (N=98) and infants without family members with autism (N=36). MRI scans were also examined for radiologic abnormalities

Results: No group differences were observed for intracranial, cerebrum, cerebellum, or lateral ventricle volume or for head circumference.

Conclusions: The authors did not observe significant group differences for head circumference, brain volume, or abnormalities in radiologic findings from a group of 6-month-old infants at high risk for autism. The authors are unable to conclude that these abnormalities are not present in infants who later go on to receive a diagnosis of autism; rather, abnormalities were not detected in a large group at high familial risk. Future longitudinal studies of the IBIS study group will examine whether brain volume differs in infants who go on to develop autism.
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http://dx.doi.org/10.1176/appi.ajp.2012.11091425DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3744332PMC
June 2012