The effects of the skull on CT imaging of the brain: a skull and brain phantom study.

Objective: To investigate the effects of beam hardening by the skull on the measured radiodensity of the brain. To test a hypothesis that these effects of beam hardening are decreased using a monochromatic energy source.

Methods: Selected clinical cases were reviewed in illustration.

Automated Estimation of Acute Infarct Volume from Noncontrast Head CT Using Image Intensity Inhomogeneity Correction.

Identification of early ischemic changes (EIC) on noncontrast head CT scans performed within the first few hours of stroke onset may have important implications for subsequent treatment, though early stroke is poorly delimited on these studies. Lack of sharp lesion boundary delineation in early infarcts precludes manual volume measures, as well as measures using edge-detection or region-filling algorithms. We wished to test a hypothesis that image intensity inhomogeneity correction may provide a sensitive method for identifying the subtle regional hypodensity which is characteristic of early ischemic infarcts.

A Radiodensity Histogram Study of the Brain in Multiple Sclerosis.

Multiple sclerosis (MS) is a progressive neurodegenerative disease, affecting 1 million Americans and 2.5 million people globally. Although the diagnosis is made clinically, imaging plays a major role in diagnosing and monitoring disease progression and treatment response.

Local control and overall survival for adjuvant stereotactic radiosurgery in patients with residual or recurrent disease.

Prior studies of post-operative stereotactic radiosurgery (SRS) have not distinguished between Adjuvant SRS (ARS) versus Adjuvant SRS to residual/recurrent disease (ARD). In this study, we defined ARS and ARD and investigated local control (LC), overall survival (OS), distant development of brain metastases (DBF), and leptomeningeal disease (LMD). We retrospectively identified BM patients who received surgical resection and SRS for BM from an IRB approved database between Jan 2009-Aug 2015.

Automated Segmentation of Head Computed Tomography Images Using FSL.

Objective: The aim of this study was to investigate the use of one magnetic resonance image-processing tool, FSL, in its ability to perform automated segmentation of computed tomographic images of the brain.

Methods: Head computed tomography (CT) images were brain extracted and segmented using the FSL tools BET and FAST, respectively. The products of segmentation were analyzed by histogram.

Evaluation of neonatal brain myelination using the T1- and T2-weighted MRI ratio.

Purpose: To validate the T1- and T2-weighted (T1w/T2w) MRI ratio technique in evaluating myelin in the neonatal brain.

Materials And Methods: T1w and T2w MR images of 10 term neonates with normal-appearing brain parenchyma were obtained from a single 1.5 Tesla MRI and retrospectively analyzed.

Fluoroscopically Guided Lumbar Puncture.

Objective: The objective of this article is to detail the indications, techniques, risks, and benefits of fluoroscopically guided lumbar puncture (LP).

Conclusion: Familiarity with the details of fluoroscopically guided LP can aid in the work flow, increase the success rate, and minimize the complications of the procedure.

Lesions of the corpus callosum and other commissural fibers: diffusion tensor studies.

The corpus callosum is the largest white matter tract in the brain, connecting the 2 hemispheres. The functions of the corpus callosum are many and varied, and lesions frequently cause only subtle clinical findings. The range of diseases that can affect the corpus callosum is vast and includes all potential white matter disease.

Axial diffusivity of the corona radiata correlated with ventricular size in adult hydrocephalus.

Objective: Hydrocephalus causes changes in the diffusion-tensor properties of periventricular white matter. Understanding the nature of these changes may aid in the diagnosis and treatment planning of this relatively common neurologic condition. Because ventricular size is a common measure of the severity of hydrocephalus, we hypothesized that a quantitative correlation could be made between the ventricular size and diffusion-tensor changes in the periventricular corona radiata.

Apparent diffusion coefficient histogram analysis of neonatal hypoxic-ischemic encephalopathy.

Background: Diffusion-weighted imaging is a valuable tool in the assessment of the neonatal brain, and changes in diffusion are seen in normal development as well as in pathological states such as hypoxic-ischemic encephalopathy (HIE). Various methods of quantitative assessment of diffusion values have been reported. Global ischemic injury occurring during the time of rapid developmental changes in brain myelination can complicate the imaging diagnosis of neonatal HIE.

Spinal diffusion tensor imaging: a comprehensive review with emphasis on spinal cord anatomy and clinical applications.

Magnetic resonance imaging technology allows for in vivo visualization of fiber tracts of the central nervous system using diffusion-weighted imaging sequences and data processing referred to as "diffusion tensor imaging" and "diffusion tensor tractography." While protocols for high-fidelity diffusion tensor imaging of the brain are well established, the spinal cord has proven a more difficult target for diffusion tensor methods. Here, we review the current literature on spinal diffusion tensor imaging and tractography with special emphasis on neuroanatomical correlations and clinical applications.

Diffusion-tensor imaging of small nerve bundles: cranial nerves, peripheral nerves, distal spinal cord, and lumbar nerve roots--clinical applications.

Objective: The purpose of this article is to review recent advances in diffusion-tensor imaging (DTI) and tractography of the cranial and peripheral nerves.

Conclusion: Advances in MR data acquisition and postprocessing methods are permitting high-resolution DTI of the cranial and peripheral nerves in the clinical setting. DTI offers information beyond routine clinical MRI, and DTI findings have implications for the diagnosis and treatment of nerve disease.

Improved image quality and detection of small cerebral infarctions with diffusion-tensor trace imaging.

Objective: The purpose of this study was to test a hypothesis that routinely performed diffusion-tensor trace imaging is of sufficient image quality and sensitivity for infarct detection to safely and routinely replace standard diffusion-weighted imaging (DWI) in the clinical setting.

Materials And Methods: Both routine DWI and 15-direction diffusion-tensor imaging (DTI) with parallel acquisition technique were obtained on all brain MRI studies from a single 1.5-T MRI scanner at a tertiary care referral center over a 1-year period, permitting direct comparison of the two different diffusion studies on the same patients (2537 studies, 365 infarct-positive studies).

Diffusion-tensor imaging derived metrics of the corpus callosum in children with neurofibromatosis type I.

Objective: MR morphometric studies have suggested that structural brain abnormalities including corpus callosum enlargement may, in part, explain cognitive deficits in children with neurofibromatosis type 1 (NF-1). Diffusion tensor imaging (DTI) metrics of the corpus callosum in adults with NF-1 have recently been reported, but such studies in children with NF-1 are needed. The purpose of this study was to quantify the DTI metrics at 3 T of different regions of the corpus callosum in children with NF-1.

MR imaging of acute cervical spinal ligamentous and soft tissue trauma.

The increasing availability of magnetic resonance imaging (MRI) and the high sensitivity of MRI for soft tissue injury are resulting in the increased use of MRI for the evaluation of acute trauma. As cervical spine injury can have a devastating consequence, MRI is being more commonly used to evaluate cervical spine injury in the acute setting, necessitating emergent interpretation by the on-call radiologist. Unless one is formally trained in a trauma center, the MRI findings of soft tissue and ligamentous cervical spine injury may not be fully appreciated.

Magnetic resonance diffusion tensor imaging (MRDTI) of the optic nerve and optic radiations at 3T in children with neurofibromatosis type I (NF-1).

Background: Optic pathway glioma (OPG) is a characteristic hallmark of neurofibromatosis type I (NF-I).

Objective: To evaluate the feasibility of magnetic resonance diffusion tensor imaging (MRDTI) at 3T to detect abnormalities of the optic nerves and optic radiations in children with NF-I.

Materials And Methods: 3-T MRDTI was prospectively performed in 9 children with NF-I (7 boys, 2 girls, average age 7.

Magnetic resonance diffusion tensor imaging and tractography of the lower spinal cord: application to diastematomyelia and tethered cord.

Objectives: To investigate the feasibility of routine clinical DTI of the lower spinal cord using high-field-strength MRI and parallel imaging, and to evaluate the utility of diffusion tensor imaging and tractography as tools for study of lower cord pathology.

Methods: Three patients with diastematomyelia, one patient with tethered cord, and six normal volunteers underwent MR imaging of the lower spine at 3 T. A 15-channel spine coil and parallel imaging were used with a six-direction single-shot echo-planar gradient echo technique.

Magnetic resonance diffusion tensor imaging and tractography of intracranial cavernous malformations: preliminary observations and characterization of the hemosiderin rim.

Object: Cavernous malformations (CMs) can cause symptoms that appear out of proportion to the lesion size, leading one to hypothesize that they may have an effect on adjacent white matter that is not fully explained by local mass effect. The goal of this study was to investigate the diffusion tensor (DT) properties of CMs, the hemosiderin rim, and normal-appearing adjacent white matter.

Methods: Eighteen cavernous malformations were characterized using standard MR imaging sequences as well as 6-direction DT imaging with single-shot echo planar-gradient echo imaging at 3 tesla.

Magnetic resonance diffusion tensor imaging of the optic nerves to guide treatment of pediatric suprasellar tumors.

Background/aims: As a preoperative planning tool, conventional magnetic resonance (MR) imaging may have limited value in differentiating tumors from white matter tracts. MR diffusion tensor imaging (MRDTI) has become a useful tool for evaluating white matter tracts in relation to surrounding structures and has been used in surgical planning for brain tumors involving white matter. We investigated the use of DTI of the optic nerves in surgical planning for pediatric suprasellar tumors.

Magnetic resonance diffusion tensor imaging (MRDTI) and tractography in children with septo-optic dysplasia.

Background: Septo-optic dysplasia (SOD) refers to a heterogeneous group of midline brain developmental anomalies, with optic nerve hypoplasia (ONH) being one of the morphologic correlates of the condition. Traditionally, ONH has been diagnosed on fundoscopic exam. Conventional MRI is used in cases of suspected ONH to identify associated brain abnormalities and to compare findings to the fundoscopic exam.

Serial follow-up MRI of indeterminate cystic lesions of the pineal region: experience at a rural tertiary care referral center.

Objective: The purpose of this study was to retrospectively assess the outcomes of temporal MRI follow-up of indeterminate cystic lesions of the pineal region.

Materials And Methods: Cases of indeterminate pineal lesions were identified by a computerized search of radiology reports at our institution from 1998 to 2007. Twenty-six indeterminate pineal lesions, one each in 26 patients (six males and 20 females), were followed in the current study.

Diffusion tensor imaging and tractography of Rasmussen encephalitis.

A 5-year-old girl presented with intractable seizures and nonfocal hemispheric slowing on EEG. Blood, urine, and CSF laboratory values were all normal. MR imaging of the brain demonstrated diffuse volume loss of the entire left hemisphere.