Current evidence suggests that spinal cord epidural stimulation (scES) can promote aspects of motor recovery for standing, stepping and volitional lower limb movement in research participants with spinal cord injury (SCI), although the extent of such recovery varies among individuals. The goal of this retrospective cohort study was to assess (i) whether the early application of scES, prior to any training with scES, is sufficient to enhance standing ability; and (ii) which magnetic resonance imaging (MRI) biomarkers of spinal cord lesion, if any, are associated with early responsiveness to scES for standing. Twenty-nine non-ambulatory individuals with chronic, severe SCI (n = 27 clinically motor complete; n = 2 motor incomplete) underwent spinal cord MRI and were subsequently implanted with scES. Standing ability was assessed prior to epidural stimulator implant and after implant with scES parameters targeted to facilitate standing (Stand-scES). T2-weighted MRI was used to measure the following spinal cord lesion characteristics: lesion length, midsagittal tissue bridges, and estimates of spared tissue in the anterior, posterior, right, and left spinal cord regions. Early application of continuous Stand-scES significantly improved the ability to stand for longer periods (+ 17

Individuals with cervical spinal cord injury (SCI) rank regaining arm and hand function as their top rehabilitation priority post-injury. Cervical spinal cord transcutaneous stimulation (scTS) combined with activity-based recovery training (ABRT) is known to effectively facilitate upper extremity sensorimotor recovery in individuals with residual arm and hand function post SCI. However, scTS effectiveness in facilitating upper extremity recovery in individuals with severe SCI with minimal to no sensory and motor preservation below injury level remains largely unknown. We herein introduced a multimodal neuro-rehabilitative approach involving scTS targeting systematically identified various spinal segments combined with ABRT. We hypothesized that multi-site scTS combined with ABRT will effectively neuromodulate the spinal networks, resulting in improved integration of ascending and descending neural information required for sensory and motor recovery in individuals with severe cervical SCI. To test the hypothesis, a 53-year-old male (C2, AIS A, 8 years post-injury) received 60 ABRT sessions combined with continuous multi-site scTS. Post-training assessments revealed improved activation of previously paralyzed upper extremity muscles and sensory improvements over the dorsal and volar aspects of the hand. Most likely, altered spinal cord excitability and improved muscle activation and sensations resulted in observed sensorimotor recovery. However, despite promising neurophysiological evidence pertaining to motor re-activation, we did not observe visually appreciable functional recovery on obtained upper extremity motor assessments.

OBJECTIVES:To explore filtered diffusion-weighted imaging (fDWI), in comparison with conventional magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI), as a predictor for long-term locomotor and urodynamic (UD) outcomes in Yucatan minipig model of spinal cord injury (SCI). Additionally, electrical conductivity of neural tissue using D-waves above and below the injury was measured to assess correlations between fDWI and D-waves data.METHODS:Eleven minipigs with contusion SCI at T8-T10 level underwent MRI at 3T 4 h. post-SCI. Parameters extracted from region of interest analysis included Daxial from fDWI at injury site, fractional anisotropy and radial diffusivity from DTI above the injury site along with measures of edema length and cord width at injury site from T2 -weighted images. Locomotor recovery was assessed pre- and weekly post-SCI through porcine thoracic injury behavior scale (PTIBS) and UD were performed pre- and at 12 weeks of SCI. D-waves latency and amplitude differences were recorded before and immediately after SCI.RESULTS:Two groups of pigs were found based on the PTIBS at week 12 (p < 0.0001) post-SCI and were labeled "poor" and "good" recovery. D-waves amplitude decreased below injury and increased above injury. UD outcomes pre/post SCI changed significantly. Conventional MRI metrics from T2 -weighted images were significantly correlated with diffusion MRI metrics. Daxial at injury epicenter was diminished by over 50% shortly after SCI, and it differentiated between good and poor locomotor recovery and UD outcomes.INTERPRETATION:Similar to small animal studies, fDWI from acute imaging after SCI is a promising predictor for functional outcomes in large animals.

Previous studies have shown that epidural stimulation of the lumbosacral spinal cord (scES) can re-enable lower limb volitional motor control in individuals with chronic, clinically motor complete spinal cord injury (SCI). This observation entails that residual supraspinal connectivity to the lumbosacral spinal circuitry still persisted after SCI, although it was non-detectable when scES was not provided. In the present study, we aimed at exploring further the mechanisms underlying scES-promoted recovery of volitional lower limb motor control by investigating neuroimaging markers at the spinal cord lesion site via magnetic resonance imaging (MRI). Spinal cord MRI was collected prior to epidural stimulator implantation in 13 individuals with chronic, clinically motor complete SCI, and the spared tissue of specific regions of the spinal cord (anterior, posterior, right, left, and total cord) was assessed. After epidural stimulator implantation, and prior to any training, volitional motor control was evaluated during left and right lower limb flexion and ankle dorsiflexion attempts. The ability to generate force exertion and movement was not correlated to any neuroimaging marker. On the other hand, spared tissue of specific cord regions significantly and importantly correlated with some aspects of motor control that include activation amplitude of antagonist (negative correlation) muscles during left ankle dorsiflexion, and electromyographic coordination patterns during right lower limb flexion. The fact that amount and location of spared spinal cord tissue at the lesion site were not related to the ability to generate volitional lower limb movements may suggest that supraspinal inputs through spared spinal cord regions that differ across individuals can result in the generation of lower limb volitional motor output prior to any training when epidural stimulation is provided.

Preparing a radiologist to safely practice our specialty is an arduous task. Many of us in academic radiology have received scant instruction in the science of education. Our instructional efforts have often been learned by mimicry, whereas educational theory, techniques, implementation, and assessment have been, at best, informal. To this end, the Accreditation Council for Graduate Medical Education (ACGME) has begun to address these deficiencies in several ways. As a prelude, perhaps it is fair to say that the methods of radiology training have evolved considerably over the last two decades, significantly improving in each of the training venues a resident must complete in order to practice without an unacceptable risk to the public: day to day supervised reading at a work station, formal didactic or interactive lectures, case conference reviews, educational reading, and self-testing.

A 68-year-old gentleman was evaluated for diplopia. Head CT showed a partially calcified midline lesion with central hypodensity (Figure 1A). Head CT angiography reported an 11-mm thrombosed basilar tip aneurysm (Figure 1B,C). Conventional digital subtraction angiography (DSA) showed no evidence of an aneurysm (Figure 1D). Brain MRI showed the well-circumscribed lesion anterior to the midbrain was hyperintense on T1 sequence (Figure 1E) but hypointense on fat saturation sequence (Figure 1F) and hypo-hyperintense on T2 (Figure 1G). The lesion had no restricted diffusion changes (Figure 1H) and was not contrast-enhanced. MRI characteristic findings with normal angiography highly suggested a dermoid cyst.1 This is the first report of a posterior fossa dermoid cyst mimicking a large thrombosed basilar tip aneurysm.

Purpose: To compare accuracy of spinal cerebrospinal fluid (CSF) pulsatile flow measurements at cervical, thoracic, and lumbar levels using Phase Contrast Cine MRI (PCCMRI) with retrospective electrocardiogram (recg) vs. retrospective peripheral pulse gating (rppg) gating. Methods: We scanned 10 healthy volunteers, ages 23-46 years, using external recg-gated or rppg-gated 2D PCCCMRI at 3T. Transverse scans of CSF, arteries and veins scans were at C1/C4/T1/T7/L1-L3. Data were analyzed with custom Matlab-based software, measuring CSF, arterial (descending aorta, abdominal aorta, common carotid artery, ICA, and vertebral artery) and venous (internal jugular vein and inferior vena cava) flow, velocity and region of interest area. Results: recgPCCMRI produced less quantitative and temporal statistical variation than pcgPCCMRI when analyzing CSF flow. The instantaneous recgPCCMRI CSF flows consistently decreased craniocaudally, while the results with rppgPCCMRI were less consistent. The recgPCCMRI root mean square error values were 6.04, 6.94, 4.81, 4.49, and 4.16 for C1, C4, T1, T7, and L2, compared with 7.24, 8.97, 7.9, 7.82, and 6.68 for rppgPCCMRI. Results were independent of analysts. Summations of standard errors produced similar results. RppgPCCMRI also showed increase variability of CSF flow correlations with arteries and veins compared to recgPCCMRI. None-the-less, when recgPCCMRI is considered the reference standard, there is good correlations between rppgPCCMRI and recgPCCMRIdata sets, when averaged over cohorts of at least five subjects. Conclusion: Our results indicated that recgPCCMRI is more quantitatively and temporally precise than rppgPCCMRI in CSF quantitative flow analysis. Pulse-gating CSF flow results are reasonable when averaged over cohorts of at least five subjects, but subtle conclusions should be interpreted with caution.

We studied relationships of cerebral spinal fluid (CSF) pulsatile flow at cervical, thoracic, and lumbar levels using phase-contrast cine MRI (PCCMRI) to determine the following: 1) instantaneous and average net flows at cervical, thoracic, and lumbar levels, 2) stochastic correlations of CSF flow with major arterial supplies and major draining veins, and 3) whether adjustments of cord-flow curves-using cord cross-sectional areas, caudal lengths, and caudal volumes-would normalize flow curves from different levels. We scanned 15 healthy volunteers without anesthesia, ages 23-46 yr, using external, retrocardiac-gated, two-dimensional PCCMRI at 3T. Transverse scans of the subarachnoid space, arteries, and veins were acquired and analyzed at cervical, thoracic, and lumbar levels. Instantaneous CSF flow decreased craniocaudally along the full time course of a cardiac cycle. Downward net flow generally increased craniocaudally. During diastole, instantaneous CSF flow decreased proportionally to cross-sectional area, caudal residual length, and caudal residual volume of the cord. The proportionalities were less consistent during systole. CSF, internal carotid artery (ICA), vertebral artery, and lower aorta temporal correlations were highest in systole and decreased craniocaudally. CSF flow temporally correlated better with lower aorta flow than with the ICA at T7 and L2 during systole but not diastole. Inferior vena cava temporal correlation increased craniocaudally. We conclude that whereas instantaneous flow is attenuated cranial caudally, net downward flow, per cardiac cycle, increases caudally, becoming statistically significant at T7 and below the conus medullaris. We can explain the results with the assumption of cord CSF production and peripheral-dominated CSF absorption.

ABSENCE OF CAUDOCRANIAL CONTINUOUS BULK FLOW By the first decade of the 20th century, it was well appreciated that the effects of lumbar intrathecal local anesthetics were largely limited to the lumbar dermatomes.2,3 The distribution was subject to several variables: higher blocks produced by larger volumes and by gravity driven distribution associated with injectate baricity.4 To achieve upper body blocks, cervical drug delivery was required5 or large volumes and cerebrospinal fluid (CSF) barbotage,6 leading to “total spinals.” This localization of effect was early evidence that largescale redistribution of intrathecal contents did not routinely occur and argued against the popular notion that spinal CSF was characterized by a continuous “bulk” movement of fluid along the posterior surface of the spinal cord that then returned cephalad.7 Consideration of the dynamics of neuraxial CSF argued against a mechanism that would enable such redistribution. Thus, early thinking on CSF formation suggested the role of the supraspinal choroid plexus.8 Later studies suggested that fluid elaboration continued in the absence of choroid plexus,9 and others have emphasized potential movement of fluid from the parenchymal extracellular space.10,11 Importantly, specific assessment has shown little CSF formation at the spinal level12 (but see13), emphasizing that, in the absence of spinally generated CSF, there would not be a “bulk” rostral neuraxial CSF flow. This absence of flow accounts for the local intrathecal drug action identified at the turn of the last century and specifically emphasized by studies on intrathecal drug redistribution in supine and vertical large animal models receiving low-volume bolus injection and low-rate infusion,14 as well as by a variety of noninvasive imaging procedures in humans and nonhuman models.

C l i n M e d International Library Citation: Bert RJ, William C III , Ney DE, Damek DM, Kleinschmidt-DeMasters BK, et al. (2017) Comparison of Arterial Spin Labeling and Dynamic Susceptibility Contrast-Enhanced MR Perfusion in Differentiating Tumor Recurrence from Treatment-Related Changes. Int J Radiol Imaging Technol 3:022 Received: February 07, 2017: Accepted: February 21, 2017: Published: February 24, 2017 Copyright: © 2017 Bert RJ, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Bert et al. Int J Radiol Imaging Technol 2017, 3:022 Volume 3 | Issue 1

In this paper, a novel method of embedding shape information into level set image segmentation is proposed. Our method is based on inferring shape variations by a sparse linear combination of instances in the shape repository. Given a sufficient number of training shapes with variations, a new shape can be approximated by a linear span of training shapes associated with those variations. At each step of curve evolution the curve is moved to minimize Chan-Vese energy functional as well as toward the best approximation based on a linear combination of training samples. Although the method is general, in this paper it has been applied to the problem of segmentation of corpus callosum from 2D sagittal MR images.

Linear sebaceous nevus syndrome (LNSS) is a rare neurocutaneous disorder associated with mental retardation, linear sebaceous nevus of Jadassohn and seizures. Characterized by Feuerstein and Mims in 1962, this disorder has been, grouped with other epidermal nevus syndromes and the phakomatoses. Five distinct epidermal nevus syndromes have been described and characterized by their epidermal nevi and organ system involvement, particularly, brain, eyes and skeleton. LNSS has been associated with hemimegalencephaly and other non-LNSS forms of epidermal nevus syndromes have been associated with hemiatrophy. We present a case of LNSS with diagnostic dermatologic, pathologic and clinical findings but unique computerized tomography and magnetic resonance imaging findings: an undersized hemisphere, unusual draining veins, thinning of the left temporal and occipital cortices ipsilateral to the linear nevus and left frontal bone focal scalloping. We have not found the combination of a vascular anomaly and undersized hemisphere specifically described with LNSS, although a few cases of cerebrovascular abnormality have been associated with LNSS. We discuss the radiologic findings in context of known embryology to favor hemihypoplasia over hemiatrophy. We hope that this case report will lead to further investigations in the pathophysiology and genetics of this disorder.

Computed tomography (CT) plays a pivotal role in the diagnosis of acute stroke and in treatment decision making. CT perfusion imaging performed with intravenous iodinated contrast material allows calculation of the time to peak enhancement, mean transit time, and cerebral blood volume, important parameters for differentiating between an ischemic penumbra, which might benefit from intravascular therapy with thrombolytic agents, and infarcted tissue, which would not benefit from such therapy. Differentiation between the two entities is important because thrombolytic therapy is associated with an increased risk for intracranial hemorrhage. A finding of delay in peak enhancement or increased mean transit time in a region with normal or only slightly abnormal cerebral blood volume is suggestive of an ischemic penumbra; however, accurate interpretation of the CT perfusion parameters may be difficult in the presence of a cerebrovascular anatomic variant or physiologic condition that produces benign oligemia leading to a false appearance of penumbra. For this reason, CT perfusion parameters must be correlated with the clinical history and findings at unenhanced head CT, angiography or CT angiography, and diffusion-weighted magnetic resonance imaging. The authors identify five possible causes of false penumbras, each of which produces a different pattern at imaging: upstream flow restriction, evolution of ischemic change, vascular dysregulation, positioning of the patient's head at an angle during image acquisition, and variant anatomy in the circle of Willis. Familiarity with the imaging patterns and causes of false penumbras may increase the radiologist's confidence in diagnosis and help avoid costly errors in treatment.

Purpose: To measure T-1 and T-2 of the fine structures of the in vivo eye.Materials and Methods: Involuntary saccades make it difficult to obtain artifact-free images. Using a method recently reported (Bert et al, Acad Radiol 2006; 12:368-378), near artifact-free spin-echo images were obtained. Both an isolated enucleated eye and eight human subjects were studied at 1.5T. Spin-echo variable TRITE data was acquired for T-1/T-2 determination. Average relaxation times were calculated two ways. First, an arithmetic average over different subjects was computed. Second, all data was normalized using the fitted amplitudes of each data set and pooled to obtain a single least squares fit.Results: In vivo T-1/T-2 (msec) are: arithmetic average T-1, T-2, normalized data T1, T2. Anterior chamber: 6233 +/- 979, 468 +/- 149, 5053 +/- 1052, 450 1 +/- 49. Ciliary body: 1916 +/- 184, 80 +/- 7, 2038 +/- 114, 76 +/- 3. Chorioretina: 1717 +/- 500, 72 +/- 25, 1511 1 +/- 230, 78 +/- 3. Extraocular muscle: 1581 +/- 646, 41 +/- 7, 1470 +/- 231, 41 +/- 1. Iris: 3334 +/- 989, 163 +/- 63, 3376 +/- 338, 153 +/- 10. Lens cortex: 1712 +/- 466, 93 +/- 36, 1413 +/- 177, 100 +/- 5. Lens nucleus: 1133 +/- 40, 26 +/- 3, 1138 +/- 47, 25 +/- 0.4. Optic nerve: 1906 +/- 301, 6816, 1805 +/- 244, 71 +/- 2. Posterior chamber: 7915 +/- 4897, 241 +/- 14, 3323 +/- 2154, 251 +/- 38. Vitreous humor: 5768 +/- 1190, 756 +/- 804, 4855 +/- 1846, 390 +/- 8.Conclusion: In vivo T-1 and T-2 for many of the fine structures of the human eye have been measured.

PURPOSE:The present studies were conducted to determine whether a diffusional pathway for solutes exists from the ciliary body stroma to the anterior chamber of the human eye. The existence of such a pathway has been demonstrated in rabbits and monkeys, but such a pathway in humans would necessitate a shift in the physiological paradigm of the blood-aqueous barrier.METHODS:Seven normal human volunteers (five men, two women; age range, 27 to 59 years) underwent nine dynamic T1-weighted, spin-echo MR imaging studies, using intravenous, gadolinium-based contrast agents.RESULTS:In all cases, signal intensity rose rapidly in the ciliary body. In all subjects, there was a measurable latent rise in signal strength (enhancement) in the anterior chamber. Signal enhancement typically occurred in the angle of the anterior chamber earlier, and to a greater degree, than within the center of the chamber. Increased signal within the posterior chamber was significantly less than in the anterior chamber, with measured increases probably attributable to volume averaging.CONCLUSIONS:These findings are consistent with the existence of an anterior diffusional pathway in the human eye. The model warrants further testing.