Why Is This Auntminnie a Diagnostic Conundrum?: A Knowledge-Based Approach to Balo's Concentric Sclerosis From Reports of 3 Cases and Pooled Data From 68 Other Patients in the Literature.

INTRODUCTION: We came across 3 cases of Balo's concentric sclerosis (BCS). The first of these patients presented to an outside hospital and was transferred to our institution due to complications resulting from a biopsy. The other 2 patients, despite having a characteristic imaging appearance and despite insistence on our part on the diagnosis of BCS, underwent a surgical procedure, which could have been prevented. This led us to review the available literature on BCS. MATERIAL AND METHODS: A total of 68 patients diagnosed with BCS between 1995 and 2015 were studied and the data collected for the clinical presentation and course, imaging, spinal fluid analysis, treatment, and clinical and imaging outcome. CONCLUSIONS: A 25% surgery rate (biopsy or resection) was found in the study. We concluded that this relatively high surgery rate in this auntminnie nonsurgical disease is multifactorial; and includes factors like nonfamiliarity with the disease, anxiety on the part of patients and physicians, due to a sometimes rapidly deteriorating clinical picture; and resemblance of the disease with other entities such as tumor and infection. However, characteristic imaging appearance combined with acute or subacute presentation and dramatic improvement in clinical status after high-dose steroid chemotherapy; are highly suggestive of the disease, and can prevent unnecessary surgery.

Interobserver Reliability of Magnetic Resonance Imaging Predictors of Outcome in Cervical Spine Degenerative Conditions.

BACKGROUND: Although recent work has focused on characterizing quantitative magnetic resonance imaging (MRI) markers that may predict outcome among patients with cervical degenerative conditions, little is known about their reliability. Measurement and reporting of these markers is time-consuming and nonstandardized, preventing routine use in clinical care. METHODS: We retrospectively analyzed cervical MRI among subjects prospectively enrolled in a health outcomes study of elective surgery for degenerative cervical spine conditions. Two radiologists independently reviewed MRI for presence or absence and length of cord signal change, level of worst cord compression, axial anteroposterior (AP) and lateral spinal cord diameter, midsagittal AP diameter, and kyphosis. Interobserver reliability was compared using kappa and intraclass correlation coefficient (ICC). RESULTS: Inclusion criteria were met by 209 patients who had MRI available for review. Most patients were female (58%) and middle-aged (mean age 51 years), and 54% had a diagnosis of myelopathy. Reliability was fair for cord signal change on T1 (κ = 0.33) and good on T2 (κ = 0.74) images. Among patients with T2 change (n = 22), reliability for signal change length was good (ICC = 0.67). For level of worst compression, reliability was good (κ = 0.79). For AP cord diameter, reliability was very good (ICC = 0.82; T2/midsagittal) and good (ICC = 0.66; T2/axial). Reliability was moderate for lateral cord diameter (ICC = 0.55; T2/axial) and good for kyphosis (κ = 0.76). CONCLUSIONS: Good and very good reliability observed in measuring T2-weighted spinal cord signal change, level of worst compression, AP cord diameter, and kyphosis support use of these markers in standardized reporting, which could be incorporated into routine clinical use.

Imaging of Cerebrovascular Disease in Pregnancy and the Puerperium.

OBJECTIVE: The purpose of this article is to review the unique physiologic changes that characterize pregnancy and the puerperium, some that substantially affect the cerebrovascular system. Conditions that can cause neurologic deterioration and share features with preeclampsia-eclampsia include postpartum angiopathy, reversible cerebral vasoconstriction syndrome, posterior reversible encephalopathy syndrome, and amniotic fluid embolism. Other conditions not specific to this patient group include cerebral venous thrombosis, cervicocephalic arterial dissection, ischemic stroke, and hemorrhagic stroke, which can pose specific diagnostic and therapeutic challenges. CONCLUSION: Radiologists must be familiar with the imaging findings of cerebrovascular complications and pathologic entities encountered during pregnancy and the puerperium. Ongoing improvements in understanding of molecular changes during pregnancy and the puerperium and advances in diagnostic tests should allow radiologists to continue to make important contributions to the care of this patient population.

Imaging correlates of neural control of ocular movements.

The purpose of oculomotor movements is maintenance of clear images on the retina. Beyond this oversimplification, it requires several different types of ocular movements and reflexes to focus objects of interest to the fovea-the only portion of retina capable of sharp and clear vision. The different movements and reflexes that execute this task are the saccades, smooth pursuit movements, fixation, accommodation, and the optokinetic and vestibulo-ocular reflexes. Many different centres in the cerebrum, cerebellum, brainstem and thalami, control these movements via different pathways. At the outset, these mechanisms appear dauntingly complex to a radiologist. However, only a little effort could make it possible to understand these neural controls and empower the reading session. The following review on ocular movements and their neural control will enable radiologists and clinicians to correlate lesions with clinical deficits effectively without being swamped by exhaustive detail. Key Points • Knowledge of cortical and subcortical areas controlling ocular movements is important. • Understanding of neural control of ocular movements makes a good foundation. • Awareness of anatomic areas controlling ocular movements helps in clinico-radiologic correlation.

Functional and Dysfunctional Sensorimotor Anatomy and Imaging.

The sensorimotor system of the human brain and body is fundamental only in its central role in our daily lives. On further examination, it is a system with intricate and complex anatomical, physiological, and functional relationships. Sensorimotor areas including primary sensorimotor, premotor, supplementary motor, and higher order somatosensory cortices are critical for function and can be localized at routine neuroimaging with a familiarity of sulcal and gyral landmarks. Likewise, a thorough understanding of the functions and dysfunctions of these areas can empower the neuroradiologist and lead to superior imaging search patterns, diagnostic considerations, and patient care recommendations in daily clinical practice. Presurgical functional brain mapping of the sensorimotor system may be necessary in scenarios with distortion of anatomical landmarks, multiplanar localization, homunculus localization, congenital brain anomalies, informing diffusion tensor imaging interpretations, and localizing nonvisible targets.

Imaging of Cortical and White Matter Language Processing.

Although investigations into the functional and anatomical organization of language within the human brain began centuries ago, it is recent advanced imaging techniques including functional magnetic resonance imaging and diffusion tensor imaging that have helped propel our understanding forward at an unprecedented rate. Important cortical brain regions and white matter tracts in language processing subsystems including semantic, phonological, and orthographic functions have been identified. An understanding of functional and dysfunctional language anatomy is critical for practicing radiologists. This knowledge can be applied to routine neuroimaging examinations as well as to more advanced examinations such as presurgical brain mapping.

Imaging of Functional and Dysfunctional Episodic Memory.

A foundational framework for understanding functional and dysfunctional imaging of episodic memory emerges from the last 3 decades of human and animal research. This comprehensive review is presented from the vantage point of the fornix, a white matter bridge that occupies a central position in this functional network. Salient insights are identified, spanning topics such as hippocampal efferent and afferent networks, input and processing streams, hemispheric specialization, dysfunctional effects of pathologic and surgical injury, optimization of functional magnetic resonance imaging design and neuropsychological tests, and rehabilitation strategies. Far-reaching implications are considered for radiologists, whose clinical effect stretches beyond imaging and interfaces with neurosurgeons, neuropsychologists, and other neurospecialists.

Cortical and Subcortical Substrates of Cranial Nerve Function.

The pivotal role of cranial nerves in a wholesome life experience cannot be overemphasized. Research has opened new avenues to understand cranial nerve function. Classical concept of strict bilateral cortical control of cranial nerves has given way to concepts of hemispheric dominance and hemispheric lateralization. An astute Neuroradiologist should keep abreast of these concepts and help patients and referring physicians by applying this knowledge in reading images. This chapter provides an overview of cranial nerve function and latest concepts pertaining to their cortical and subcortical control.

Preoperative diffusion tensor imaging: improving neurosurgical outcomes in brain tumor patients.

Preoperative mapping has revolutionized neurosurgical care for brain tumor patients. Maximizing resections has improved diagnosis, optimized treatment algorithms, and decreased potentially devastating postoperative deficits. Although mapping has multiple steps and complimentary localization sources, diffusion tensor imaging (DTI) excels in its essential role in depicting white matter tracts. A thorough understanding of DTI, data visualization methods, and limitations with mastery of functional and dysfunctional white matter anatomy is necessary to realize the potential of DTI. By establishing spatial relationships between lesion borders and functional networks preoperatively and intraoperatively, DTI is central to high-risk neurosurgical resections and becoming the standard of care.

In emergency departments, radiologists' access to EHRs may influence interpretations and medical management.

The adoption of electronic health records (EHRs) that meet federal meaningful-use standards is a major US national policy priority. Policy makers recognize the potential of electronic communication in delivering high-quality health care, particularly in an environment of expanding remote access to medical care and the ever-increasing need to transmit health care records across institutions. To demonstrate this principle, we sought to estimate the significance of EHR access in emergent neuroradiologic interpretations. Three neuroradiologists conducted a prospective expert-rater analysis of 2,000 consecutive head computed tomography (CT) exams ordered by emergency department (ED) physicians. For each head CT exam, the neuroradiologists compared medical information generated by ED physicians to information generated by the interpreting radiologists who had access to additional EHR-derived patient data. In 6.1 percent of the head CT exams, the neuroradiologists reached consensus--meaning two out of three agreed--that the additional clinical data derived from the EHR was "very likely" to influence radiological interpretations and that the lack of that data would have adversely affected medical management in those patients. Health care providers must recognize the value of implementing EHRs and foster their widespread adoption.

MR-spectroscopic findings in juvenile-onset Huntington's disease.

Seven HD gene positive individuals under the age of 21 years are described with clinical examination and proton-MR-spectroscopy ((1)H-MRS) profiles of the putamen. Despite clinical variability, the predominate (1)H-MRS abnormality is elevated glutamate, expressed well beyond the confines of the basal ganglia, and low striatal creatine.

Proton magnetic resonance spectroscopy of the hippocampus in patients with mild cognitive impairment: a pilot study.

OBJECTIVE: To assess the brain metabolites in the hippocampus of patients with mild cognitive impairment (MCI) using proton magnetic resonance spectroscopy at 0.5 T. METHODS: Absolute concentrations and ratios to creatine of N-acetyl aspartate, myoinositol, glutamate + glutamine, and choline were measured in the right and left hippocampus of 5 MCI patients and 5 control subjects. RESULTS: In MCI subjects, reduced N-acetyl aspartate was found in the right hippocampus (P = 0.01), and increased myoinositol was found in the left hippocampus (P = 0.02). Myoinositol/N-acetyl aspartate ratios were higher in the right (P = 0.03) and left (P = 0.01) hippocampus of MCI subjects. No significant difference in the concentration of glutamate + glutamine was observed between the control and MCI groups. CONCLUSIONS: An increase in myoinositol and a decrease in N-acetyl aspartate may be observed in the preclinical stages of dementia. Ratio measurements of these metabolites may serve as a biomarker for MCI.

The influence of gender on auditory and language cortical activation patterns: preliminary data.

PURPOSE AND BACKGROUND: Intersex cortical and functional asymmetry is an ongoing topic of investigation. In this pilot study, we sought to determine the influence of acoustic scanner noise and sex on auditory and language cortical activation patterns of the dominant hemisphere. MATERIALS AND METHODS: Echoplanar functional MR imaging (fMRI; 1.5T) was performed on 12 healthy right-handed subjects (6 men and 6 women). Passive text listening tasks were employed in 2 different background acoustic scanner noise conditions (12 sections/2 seconds TR [6 Hz] and 4 sections/2 seconds TR [2 Hz]), with the first 4 sections in identical locations in the left hemisphere. Cross-correlation analysis was used to construct activation maps in subregions of auditory and language relevant cortex of the dominant (left) hemisphere, and activation areas were calculated by using coefficient thresholds of 0.5, 0.6, and 0.7. RESULTS: Text listening caused robust activation in anatomically defined auditory cortex, and weaker activation in language relevant cortex of all 12 individuals. As a whole, there was no significant difference in regional cortical activation between the 2 background acoustic scanner noise conditions. When sex was considered, men showed a significantly (P < .01) greater change in left hemisphere activation during the high scanner noise rate condition than did women. This effect was significant (P < .05) in the left superior temporal gyrus, the posterior aspect of the left middle temporal gyrus and superior temporal sulcus, and the left inferior frontal gyrus. CONCLUSION: Increase in the rate of background acoustic scanner noise caused increased activation in auditory and language relevant cortex of the dominant hemisphere in men compared with women where no such change in activation was observed. Our preliminary data suggest possible methodologic confounds of fMRI research and calls for larger investigations to substantiate our findings and further characterize sex-based influences on hemispheric activation patterns.

Heterogeneity in 1H-MRS profiles of presymptomatic and early manifest Huntington's disease.

OBJECTIVE: To evaluate (1)H-MRS profiles of the putamen in presymptomatic and manifest Huntington's disease (HD) patients for spectroscopic markers that are reliable, consistent signs of early pathology and to look for hemispheric differences as signs of use activation in an accelerated degradative process of the dominant hemisphere. METHODS: A short echo time Point RESolved Spectroscopy (PRESS) spectroscopic imaging study was performed at low field (0.5 Tesla, T) on 27 right-handed patients (17 presymptomatic gene carriers and 10 manifest patients of less than 3 years from clinical onset) and 10 right-handed normal volunteers. Spectra from individual voxels (0.56 cm(3)) in the putamen were selected for analysis. Resonance areas of peaks were normalized to water as a concentration standard. Interhemispheric comparisons were made in individuals in all three groups to look for hemispheric differences. RESULTS: Two presymptomatic patients showed normal spectra but all other HD patients displayed some combination of reduced N-acetylaspartate (NAA), enhanced glutamate/glutamine (Glx) activity, and lactate (Lac) elevations or reduced creatine (Cr). Rather than showing any one metabolite as pathognomonic of early change, spectroscopic profiles showed heterogeneity between HD patients. Low creatine was common in the presymptomatic but not in the manifest group. Hemispheric ratios of abnormal metabolites showed lower values of NAA and Glx in the dominant hemisphere in all three groups but values of creatine were selectively lower in the dominant hemisphere of only the presymptomatic patients. Lac was elevated in both hemispheres but less so in the dominant hemisphere in all HD patients. CONCLUSIONS: (1)H-MRS profiles from the putamen of presymptomatic and manifest patients reflect heterogeneity in pathophysiology. With the possible exception of low creatine in presymptomatic patients (1)H-MRS spectra are not suggestive of hemispheric differences supportive of an overall accelerated degradative process in the dominant hemisphere.

Two-dimensional excitation short echo time chemical shift imaging at 0.5 tesla.

Detection of short T2 metabolites such as glutamate and glutamine (glx) in the brain can be improved by minimizing the echo time (TE) of the pulse sequence. By combining two dimensions of localization during a single radiofrequency (RF) pulse, an elliptic excitation chemical shift imaging sequence (EECSI) that further reduces TE by a factor of 2 relative to a TE-optimized point resolved spectroscopy sequence chemical shift imaging sequence was developed. An additional set of outer volume saturation pulses is included to minimize the contamination from scalp and marrow space lipids. The sequence runs with conventional gradient hardware (1 G/cm, 17 T/m/s slew rate) at 0.5 T. The increase in the fitted areas of beta,gamma multiplet of glutamate and glx in a brain-mimicking phantom was by a factor of 1.66. In the thalamus of healthy volunteers, glx was increased by 1.44. Combined with the field strength-related improvements in glutamate and glx detection previously demonstrated at 0.5 T, EECSI offers further improvements for imaging glutamate and glx in vivo.

Pseudo-reorganization of language cortical function at fMR imaging: a consequence of tumor-induced neurovascular uncoupling.

A left-handed patient with a grade II left frontal lobe astrocytoma had spontaneous seizures causing speech arrest and uncontrolled right upper extremity movements. Word-generation functional MR (fMR) imaging showed activity nearly exclusively in the right inferior frontal gyrus. The clinical history of the speech arrest and the intraoperative mapping proved left-hemisphere language dominance. Tumor involvement of the left inferior frontal gyrus caused uncoupling of the blood oxygenation level-dependent (BOLD) and neuronal response, leading to the erroneous fMR imaging appearance of right-hemisphere language dominance. Discrepancies between BOLD and intraoperative mapping in areas near lesions illustrate the complementary nature of these techniques.

The ascending pharyngeal artery: branches, anastomoses, and clinical significance.

Neuroradiologists generally do not fully appreciate the importance of the territory of the ascending pharyngeal artery. The ascending pharyngeal artery is a small but important artery that supplies multiple cranial nerves and anastomotic channels to the anterior and posterior cerebral circulations. Several disease processes in the head and neck involve the ascending pharyngeal artery. To evaluate and treat such diseases, it is necessary for neuroradiologists not only to know selective angiography and embolization techniques, but also the territory of the ascending pharyngeal artery, anastomoses, and vascular supply to the vasa nervorum of lower cranial nerves. Herein, the normal angiographic anatomy of the ascending pharyngeal artery, its relationship with neighboring territories, its importance in clinical situations, and research models are reviewed.