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T Young Poussaint,
P C Phillips,
S Vajapeyam,
F H Fahey,
R L Robertson,
S Osganian,
U Ramamurthy,
R V Mulkern,
S T Treves,
J M Boyett,
L E Kun
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ABSTRACT: As an essential part of the National Cancer Institute (NCI)-funded Pediatric Brain Tumor Consortium (PBTC), the Neuroimaging Center (NIC) is dedicated to infusing the study of pediatric brain tumors with imaging "best practice" by producing a correlative research plan that 1) resonates with novel therapeutic interventions being developed by the wider PBTC, 2) ensures that every PBTC protocol incorporates an imaging "end point" among its objectives, 3) promotes the widespread implementation of standardized technical protocols for neuroimaging, and 4) facilitates a quality assurance program that complies with the highest standards for image data transfer, diagnostic image quality, and data integrity. To accomplish these specific objectives, the NIC works with the various PBTC sites (10 in all, plus NCI/ National Institute of Neurological Diseases and Stroke representation) to ensure that the overarching mission of the consortium--to better understand tumor biology and develop new therapies for central nervous system tumors in children--is furthered by creating a uniform body of imaging techniques, technical protocols, and standards. Since the inception of the NIC in 2003, this broader mandate has been largely accomplished through a series of site visits and meetings aimed at assessing prevailing neuroimaging practices against NIC-recommended protocols, techniques, and strategies for achieving superior image quality and executing the secure transfer of data to the central PBTC. These ongoing evaluations periodically examine investigations into targeted drug therapies. In the future, the NIC will concentrate its efforts on improving image analysis for MR imaging and positron-emission tomography (PET) and on developing new ligands for PET; imaging markers for radiation therapy; and novel systemic, intrathecal, and intralesional therapeutic interventions.
American Journal of Neuroradiology 05/2007; 28(4):603-7. · 2.93 Impact Factor
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I A Anselm,
I M Anselm,
F S Alkuraya,
G S Salomons,
C Jakobs,
A B Fulton,
M Mazumdar,
M Rivkin,
R Frye, T Young Poussaint,
D Marsden
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ABSTRACT: We report two unrelated boys with the X-linked creatine transporter defect (CRTR) and clinical features more severe than those previously described with this disorder. These two boys presented at ages 12 and 30 months with severe mental retardation, absent speech development, hypotonia, myopathy and extra-pyramidal movement disorder. One boy has seizures and some dysmorphic features; he also has evidence of an oxidative phosphorylation defect. They both had classical absence of creatine peak on brain magnetic resonance spectroscopy (MRS). In one, however, this critical finding was overlooked in the initial interpretation and was discovered upon subsequent review of the MRS. Molecular studies showed large genomic deletions of a large part of the 3' end of the complete open reading frame of the SLC6A8 gene. This report emphasizes the importance of MRS in evaluating neurological symptoms, broadens the phenotypic spectrum of CRTR and adds knowledge about the pathogenesis of creatine depletion in the brain and retina.
Journal of Inherited Metabolic Disease 03/2006; 29(1):214-9. · 3.58 Impact Factor
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ABSTRACT: MR assessment of pediatric brain tumors has expanded to include physiologic information related to cellular metabolites, hemodynamic and diffusion parameters. The purpose of this study was to investigate the relationship between MR and proton MR spectroscopic imaging in children with primary brain tumors. Twenty-one patients (mean age 9 years) with histologically verified brain tumors underwent conventional MR imaging, hemodynamic MR imaging (HMRI) and proton MR spectroscopic imaging (MRSI). Fourteen patients also had diffusion-weighted MR imaging (DWMRI). Metabolic indices including choline-containing compounds (Cho), total creatine (tCr) and lipids/lactate (L) were derived by proton MRSI, relative cerebral blood volume (rCBV) by HMRI, and apparent tissue water diffusion coefficients (ADC) by DWMRI. Variables were examined by linear regression and correlation as well as by ANOVA. Cho (suggestive of tumor cellularity and proliferative activity) correlated positively with rCBV, while the relationship between Cho and ADC (suggestive of cellular density) was inverse ( P<0.001). The relationship between rCBV and ADC was also inverse ( P=0.004). Cho and lipids (suggestive of necrosis and/or apoptosis) were not significantly correlated ( P=0.51). A positive relationship was found between lipids and ADC ( P=0.002). The relationships between Cho, rCBV, ADC and lipids signify that tumor physiology is influenced by the tumor's physical and chemical environment. Normalized Cho and lipids distinguished high-grade from low-grade tumors ( P<0.05). Multiparametric MR imaging using MRSI, HMRI and DWMRI enhances assessment of brain tumors in children and improves our understanding of tumor physiology while promising to distinguish higher- from lower-malignancy tumors, a distinction that is particularly clinically important among inoperable tumors.
Neuroradiology 01/2003; 45(1):1-10. · 2.82 Impact Factor
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ABSTRACT: Neuroimaging can aid in determining the causes of developmental delay in a child. Information from neuroimaging examinations may help guide further testing and treatment in these children. This article emphasizes the neuroimaging approaches, modalities, and features in the child with developmental delay. The common causative categories of developmental delay are reviewed.
Magnetic Resonance Imaging Clinics of North America 03/2001; 9(1):99-119, viii. · 1.63 Impact Factor
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A. A. Tzika,
D. Zurakowski, T. Young Poussaint,
L. Goumnerova,
L. G. Astrakas,
P. D. Barnes,
D. C. Anthony,
A. L. Billett,
N. J. Tarbell,
R. M. Scott,
P. McL. Black
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ABSTRACT: Our aim was to determine and/or predict response to treatment of brain tumors in children using proton magnetic resonance
spectroscopic imaging (MRSI). We studied 24 patients aged 10 months to 24 years, using MRI and point-resolved spectroscopy
(PRESS; TR 2000 TE 65 ms) with volume preselection and phase-encoding in two dimensions on a 1.5 T imager. Multiple logistic
regression was used to establish independent predictors of active tumor growth. Biologically vital cell metabolites, such
as N-acetyl aspartate and choline-containing compounds (Cho), were significantly different between tumor and control tissues (P < 0.001). The eight brain tumors which responded to radiation or chemotherapy, exhibited lower Cho (P = 0.05), higher total creatine (tCr) (P = 0.02) and lower lactate and lipid (L) (P = 0.04) than16 tumors which were not treated (except by surgery) or did not respond to treatment. The only significant independent
predictor of active tumor growth was tCr (P < 0.01). We suggest that tCr is useful in assessing response of brain tumors to treatment.
Neuroradiology 01/2001; 43(2):169-177. · 2.82 Impact Factor
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ABSTRACT: Background and objectives. The postoperative cerebellar mutism syndrome (CMS) is an unique acute postoperative complication characterized by transient decrease in speech output (often mutism), apathy, irritability as well as global cerebellar dysfunction. As much as 25% of patients undergoing a resection of a cerebellar or IV ventricular tumor may develop such a syndrome. In this retrospective study we characterize the clinical features of the CMS and explore potential etiologic mechanisms.
Methods. We conducted a retrospective analysis of medical records and imaging tests of 8 consecutive patients with the CMS identified through the database of the Childrens Hospital and Dana-Farber Cancer Institute, Boston, and compared with a control group of 8 unaffected children undergoing a comparable tumor resection.
Results. In contrast to the control group, children in the affected group had marked decrease in speech output and comprehension, apathy and lack of initiative, inattention, persistent eye closure, flaccid hemiparesis and a severe global cerebellar dysfunction. Swallowing difficulties and bowel and bladder dysfunction were also observed. The median duration of the syndrome as judged by the persistence of the communication abnormalities was 4 weeks. The recovery was near complete with exception for a persistent global cerebellar dysfunction. A comparison of CT and MRI scans of children in both groups failed to identify distinguishing features.
Conclusion. A surgical lesion of the midline cerebellum can cause a complex neurological dysfunction such as the CMS. Thus, we postulate that the cerebellum and its connections function as a modulatory system in control of both motor and non-motor functions, including attention and language.
Journal of Neuro-Oncology 01/2000; 48(1):75-81. · 3.21 Impact Factor
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ABSTRACT: Plain film imaging remains important for the diagnosis and surveillance of scoliosis, as well as for the detection of complications after surgery. Advances in CT and MR imaging have greatly improved the ability to detect or confirming non-idiopathic causes of scoliosis, including abnormalities within the spinal canal. Three-dimensional thinking has become more important in evaluating and understanding scoliosis.
Skeletal Radiology 12/1998; 27(11):591-605. · 1.54 Impact Factor
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ABSTRACT: Twenty-six cases of developmental retrocerebellar cyst (RCC) formation are studied with respect to determining the usefulness and anatomic relevance of separate terms currently in use, including Dandy-Walker complex, Dandy-Walker malformation, Dandy-Walker variant, mega-cisterna magna (MCM), and Blake's pouch cyst. An anatomic and embryological continuum between Dandy-Walker complex and Blake's pouch cyst is proposed. A method for the useful assessment of RCC is outlined. The patency or closure of the aqueduct is crucial to the evaluation and management of hydrocephalus associated with RCC formation.
Pediatric Radiology 06/1993; 23(4):258-260. · 1.67 Impact Factor
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American Journal of Neuroradiology 22(10):1983-4. · 2.93 Impact Factor
