Altered cerebral perfusion in children with Langerhans cell histiocytosis after chemotherapy.

Background And Purpose: Children with Langerhans cell histiocytosis (LCH) may develop a wide array of neurological symptoms, but associated cerebral physiologic changes are poorly understood. We examined cerebral hemodynamic properties of pediatric LCH using arterial spin-labeling (ASL) perfusion magnetic resonance imaging (MRI).

Materials And Methods: A retrospective study was performed in 23 children with biopsy-proven LCH.

Deep Learning in Neuroradiology.

Deep learning is a form of machine learning using a convolutional neural network architecture that shows tremendous promise for imaging applications. It is increasingly being adapted from its original demonstration in computer vision applications to medical imaging. Because of the high volume and wealth of multimodal imaging information acquired in typical studies, neuroradiology is poised to be an early adopter of deep learning.

Acute Preoperative Infarcts and Poor Cerebrovascular Reserve Are Independent Risk Factors for Severe Ischemic Complications following Direct Extracranial-Intracranial Bypass for Moyamoya Disease.

Background And Purpose: Severe ischemic changes are a rare but devastating complication following direct superficial temporal artery to MCA bypass in patients with Moyamoya disease. This study was undertaken to determine whether preoperative MR imaging and/or cerebrovascular reserve assessment by using reference standard stable xenon-enhanced CT could predict such complications.

Materials And Methods: Among all adult patients undergoing direct bypass at our institution between 2005 and 2010 who received a clinically interpretable xenon-enhanced CT examination, we identified index cases (patients with >15-mL postoperative infarcts) and control cases (patients without postoperative infarcts and without transient or permanent ischemic symptoms).

Congenital brain malformations in the neonatal and early infancy period.

Congenital brain malformations are a major cause of morbidity and mortality in pediatric patients who are younger than 2 years. Optimization of patient care requires accurate diagnosis, which can be challenging as congenital brain malformations include an extensive variety of anomalies. Radiologic imaging helps to identify the malformations and to guide management.

3D Pseudocontinuous arterial spin labeling in routine clinical practice: A review of clinically significant artifacts.

Arterial spin labeling (ASL) is a completely noninvasive magnetic resonance imaging (MRI) perfusion method for quantitatively measuring cerebral blood flow utilizing magnetically labeled arterial water. Advances in the technique have enabled the major MRI vendors to make the sequence available to the clinical neuroimaging community. Consequently, ASL is being increasingly incorporated into the routine neuroimaging protocol.

Association of developmental venous anomalies with perfusion abnormalities on arterial spin labeling and bolus perfusion-weighted imaging.

Background And Purpose: To investigate the frequency and characteristics of developmental venous anomaly (DVA)-associated perfusion abnormalities on arterial spin labeling (ASL) and bolus perfusion-weighted imaging (PWI) and discuss their potential causes.

Methods: We reviewed brain MR reports to identify all DVAs reported on studies performed between 2009 and 2012. DVA location and findings on PWI and/or ASL imaging were assessed by visual inspection.

A LASSO FOR HIERARCHICAL INTERACTIONS.

We add a set of convex constraints to the lasso to produce sparse interaction models that honor the hierarchy restriction that an interaction only be included in a model if one or both variables are marginally important. We give a precise characterization of the effect of this hierarchy constraint, prove that hierarchy holds with probability one and derive an unbiased estimate for the degrees of freedom of our estimator. A bound on this estimate reveals the amount of fitting "saved" by the hierarchy constraint.

FALSE DISCOVERY RATE ANALYSIS OF BRAIN DIFFUSION DIRECTION MAPS.

Diffusion tensor imaging (DTI) is a novel modality of magnetic resonance imaging that allows noninvasive mapping of the brain's white matter. A particular map derived from DTI measurements is a map of water principal diffusion directions, which are proxies for neural fiber directions. We consider a study in which diffusion direction maps were acquired for two groups of subjects.

Follow-up of children of depressed mothers exposed or not exposed to antidepressant drugs during pregnancy.

Objective: To compare the structural growth and developmental outcome of children born to mothers diagnosed with major depressive disorder during pregnancy who were exposed or not exposed to selective serotonin reuptake inhibitors (SSRIs) in utero.

Study Design: Children whose mothers were diagnosed with major depressive disorder in pregnancy and elected not to take medication (n = 13) were compared with children of depressed mothers treated with SSRIs (n = 31) on birth outcomes and postnatal neurodevelopmental functioning between ages 6 and 40 months. Children underwent blinded standardized pediatric and dysmorphology examinations and evaluations of their mental and psychomotor development with the use of the Bayley Scales of Infant Development (BSID II).