bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffusion‐Weighted Magnetic Resonance Imaging Abnormalities in Bartonella Encephalopathy
Authors: Singhal Aneesh B. , Newstein Michael C. , Budzik Ronald , Cha Jang‐Ho , Rordorf Guy , Buonanno Ferdinando S. , Panzara Michael A. 
Published: November 2009

ABSTRACTThe authors describe 2 patients with new‐onset, refractory status epilepticus and serological evidence for Bartonella infection. Brain magnetic resonance imaging (MRI) in patient 1 showed transient diffusion abnormalities in the posterior (pulvinar) thalami. In patient 2, brain MRI showed several enhancing cortical lesions, of which one lesion was bright on diffusion‐weighted imaging (DWI). In patients with unexplained, refractory seizures, the presence of DWI abnormalities warrants a search for unusual infectious or inflammatory disorders, like Bartonella encephalitis.
Cerebrovascular Reactivity in Hypertensive and Healthy Adolescents: TCD With Vasodilatory Challenge
Authors: Settakis Georgios , Páll Dénes , Molnár Csilla , Bereczki Dániel , Csiba László , Fülesdi Béla 
Published: November 2009

ABSTRACTBackground. Adolescent hypertension predicts hypertension and increased cardiovascular morbidity in adulthood. The aim of the present work was to test whether cerebrovascular reactivity to CO2is altered among hypertensive adolescents.Methods. From the population‐based cohort of the Debrecen Hypertension Study, 113 hypertensive and 58 normotensive adolescents underwent transcranial Doppler measurements at rest and after 30 seconds of breath holding.Results. Systolic, mean, and diastolic blood flow velocities were higher among hypertensive individuals at rest. Taking the absolute blood flow velocity parameters into account, after breath holding, only the pulsatility index was significantly higher in the hypertensive group. The percentage change of the different blood flow parameters showed less intensive change in hypertensive teenagers.Conclusion. Cerebral vasoreactivity is decreased among hypertensive individuals as compared to healthy controls.
Apolipoprotein E Genotype and Early Alzheimer's Disease: A Longitudinal SPECT Study
Authors: Sakamoto Shigeki , Matsuda Hiroshi , Asada Takashi , Ohnishi Takashi , Nakano Seigo , Kanetaka Hidekazu , Takasaki Masaru 
Published: November 2009

ABSTRACT Background and Purpose. To determine the association of the apolipoprotein E (APOE) genotype and longitudinal changes of regional cerebral blood flow (rCBF) in Alzheimer's disease (AD). Previous reports have yielded conflicting results concerning this association. Methods. A retrospective cohort study was performed. rCBF was noninvasively measured using 99mTc‐ethyl cysteinate dimer single‐photon emission computed tomography in 23 patients with probable AD at the very early stage and at a mean interval of 24 months, as well as in 55 age‐matched healthy volunteers. Patients were classified into 2 groups according to the presence of the ɛ4 allele: 11 ɛ4 carriers and 12 noncarriers. Correction for partial volume effects (PVEs) was performed in all patients using gray matter volume measured by magnetic resonance imaging. Statistical parametric mapping was used for the analysis of absolute rCBF data and the adjusted rCBF images of relative flow distribution. Results. In the baseline study, both carriers and noncarriers showed significant decreases of absolute and adjusted rCBF in the posterior cingulate gyri and precunei. After PVE correction, carriers showed a greater spread of areas with significant rCBF reduction from the parietotemporal to the frontal areas than noncarriers during the follow‐up period compared to healthy volunteers. Moreover, carriers showed a significant decline of absolute rCBF in the frontal cortex from the baseline to the follow‐up study. Conclusions. The authors' study suggests that the APOE ɛ4 allele is associated with the faster progression of AD, and PVE correction may be necessary for accurate assessments of SPECT studies of AD.
Imaging of Alzheimer's Disease
Authors: Lee Benjamin C.P. , Mintun Mark , Buckner Randy L. , Morris John C. 
Published: November 2009

ABSTRACTImaging is widely used in the evaluation of Alzheimer's disease (AD). In addition to imaging's traditional role of aiding in the exclusion of diseases that may be confused with AD, structural and functional imaging are being explored for potential use in the early detection of AD and as surrogate markers of treatment outcome. Volumetric measurements of the hippocampal and entorhinal regions using modern magnetic resonance imaging (MRI) and computed tomography are most widely studied in the discrimination of AD from nondemented aging and other dementias. Other imaging modalities include positron emission tomography and single‐photon‐emission computed tomography, which evaluate global and regional disturbances of blood flow and metabolism, and proton spectroscopy, which assesses neuronal degeneration and loss as marked by the presence of abnormal metabolites. Diffusion tensor and functional MRI, which examine whiter matter changes and brainbehavior relationships, are more recent techniques that contribute to the burgeoning application of imaging techniques to dementing illnesses and are notably improving our understanding of the pathophysiology of AD.
Neuroimaging Curriculum for Neurology Trainees: Report from the Neuroimaging Section of the AAN
Authors: Bakshi Rohit , Alexandrov Andrei V. , Gomez Camilo R. , Masdeu Joseph C. 
Published: November 2009

ABSTRACTNeuroimaging plays a major role in the evaluation of patients with neurological disorders. Surveys of neurologists have revealed that most rely on their own readings of images for patient management, and a majority believe that neurologists should be allowed to officially interpret and bill for scan reviews. The importance of neuroimaging training for neurology residents has been stressed by the Association of University Professors of Neurology. Although there is a desire to promote the neuroimaging education of neurologists, no curricula have existed previously. The Neuroimaging Section of the American Academy of Neurology (AAN) developed a task force of practicing neuroimagers to provide a neuroimaging curriculum for neurological trainees and training directors. The resulting curriculum is available on the Web sites of the AAN (http://www.aan.com) and the American Society of Neuroimaging (http://www.asnweb.org/education/curriculum.shtml) and will be updated as the need arises through evolving technology or breadth of applications. This curriculum should help in the design of neurology residency and fellowship programs and subspecialty path‐ways in which adequate neuroimaging education and training are desired for various reasons, including certification and the demonstration of competency and proficiency.
Quantification of Hippocampal Signal Intensity in Patients with Mesial Temporal Lobe Epilepsy
Authors: Coan Ana Carolina , Kobayashi Eliane , Li Li Min , Cendes Fernando 
Published: November 2009

ABSTRACT Background. Refractory mesial temporal lobe epilepsy (MTLE) is frequently associated with hippocampal atrophy (HA) and an abnormal hippocampal signal (Hsig) on magnetic resonance imaging (MRI). Objective. To quantify Hsig on MRI using a simplified technique. Methods. The authors included 15 patients with refractory MTLE who underwent surgery and had preoperative MRI with hippocampal volumetry. Hsig was quantified on preoperative coronal T1‐weighted and T2‐weighted MRI using the NIH‐Image program. Hsig was determined for the head, tail, and entire hippocampal extension. Abnormal Hsig was defined when values were above (for T2) or below (for T1) 2 standard deviations from the mean of normal control group. Results. The lateralization of abnormal Hsig values was concordant with electroencephalograms and HA in all patients. There was a significant difference in ipsilateral T2 Hsig between patients and controls (P < .0001), but not for contralateral T2 Hsig. T1 Hsig showed bilateral abnormalities more frequently, whereas T2 Hsig could lateralize better hippocampal abnormalities. Overall, there were no differences when comparing T2 Hsig for the entire hippocampus, head, or tail only. However, there were some individual differences. T2 Hsig abnormalities involved the entire hippocampus in most patients but were restricted to the head in one patient and to the tail in another. Conclusions. This simplified method for the quantification of Hsig using NHI‐Image is an efficient method for the identification and quantification of hippocampal abnormalities in patients with MTLE. The assessment of the entire extension of the hippocampal formation may provide important additional data, compared to T2 relaxometry maps limited to one segment of the hippocampus.
MRI Brain T1 Relaxation Time Changes in MS Patients Increase Over Time in Both the White Matter and the Cortex
Authors: Parry A. , Clare S. , Jenkinson M. , Smith S. , Palace J. , Matthews P. M. 
Published: November 2009

ABSTRACT Objective. To test the sensitivity of whole‐brain T1 relaxometry to the evolution of pathological changes in multiple sclerosis (MS). Background. T1‐weighted hypointense lesion load in the brains of patients with MS is associated with axonal loss. Other work has shown that T1 measurements may provide information complementary to existing imaging techniques, such as magnetization transfer imaging. Methods. The authors studied 14 MS patients twice over a median time interval of 19.5 months (range, 14–22 months). Structural images and whole‐brain T1 maps using a novel rapid‐scanning technique (3 min/study) were performed at 3 T. Analysis focused on defining changes separately in the lesional and normal‐appearing white matter (NAWM) and in the cortical gray matter. Results. At baseline, there was an inverse relationship between disease duration and the NAWM T1 histogram peak height (r=−0.75, P= .03). The total white matter T1 histogram peak height decreased over time (P < .001). This could be accounted for by changes in the NAWM (P < .03). there also was a decrease (6%) in the mean (11 of 14 patients, P= .004) and in the median (7%) (13 of 14 patients, P < .001) neocortical gray matter T1 over the follow‐up period. Conclusions. Brain T1 maps can be generated quickly and are sensitive to pathological changes over time. T1 values in both the gray and the white matter at the baseline visit were related to disease duration, suggesting that the T1 changes are clinically relevant. Although the absolute values will be different, it is likely that similar changes will be able to be detected at 1.5 T. The role of T1 measurement as a magnetic resonance imaging outcome measure in clinical trials now should be explored.
Monitoring the Effect of Chemotherapy in a Mixed Glioma by C‐11‐Methionine PET
Authors: Herholz K. , Kracht L. W. , Heiss W. D. 
Published: November 2009

ABSTRACTThe effect of chemotherapy with procarbazine, CCNU, and vincristine in an anaplastic oligoastrocytoma was monitored by repeated positron emission tomography (PET) with C‐11‐methionine (C‐11‐MET). Chemotherapy caused a continuous decline of active tumor volume at a rate of approximately 2.4% per day, resulting in complete remission that persisted until the end of follow‐up at 3 years. Thus, the authors conclude that C‐11‐MET PET may be useful for monitoring chemotherapy in gliomas and deserves further study.
Importance of Jugular Valve Incompetence in Contrast Transcranial Doppler Ultrasonography for the Diagnosis of Patent Foramen Ovale
Authors: Topçuoglu M. Akif , Buonanno Ferdinando S. 
Published: November 2009

ABSTRACTTranscranial Doppler (TCD) ultrasound with the intravenous injection of agitated saline as contrast (cTCD) is an effective method for detecting right‐to‐left intracardiac and extracardiac shunt (RLS); however, the sensitivity of cTCD in the diagnosis of RLS remains slightly less than that of transesophageal echocardiography, even in patients with adequate transtemporal ultrasonic bone windows. The authors present a case with cTCD underestimating RLS because of jugular valve incompetence in a 42‐year‐old man presenting with an episode of transient aphasia. Three weeks after transcatheter closure of a patent foramen ovale associated with an atrial septal aneurysm, he experienced 2 episodes of amaurosis fugax. Following a negative 45‐minute embolus detection study with power M‐mode TCD, the patient underwent a cTCD study with monitoring of the left middle cerebral artery (MCA), the anterior cerebral artery, and the submandibular extracranial internal carotid artery. A single microbubble (MB) was detected in the left MCA in only 1 of 5 studies; the remaining runs all failed to detect an RLS. Significant MB reflux was noted in the left internal jugular vein because of jugular valve incompetence. The authors conclude that incompetence of the jugular vein valve can result in a false negative cTCD study for RLS detection.
Brain Perfusion Imaging of a Craniopharyngioma by Transcranial Duplex Sonography
Authors: MD Thilo Hölscher , Draganski Bogdan , Postert Thomas , Bogdahn Ulrich , Wilkening Wilko 
Published: November 2009

ABSTRACT Background and Purpose. The aim of this study was to test a new ultrasound software tool to assess pathological perfusion in a brain tumor patient. Methods. Tissue harmonic imaging (THI) enables an improved depiction of brain morphology, employing nonlinear parenchyma and ultrasound contrast agent (UCA) backscatter information. With specialized software, morphological information can be separated from perfusion information. Both can be superimposed at a preferred mixing ratio in a single image. Results. Using THI and a perfluoropropane‐based UCA, a pathologic perfusion pattern described by abnormal perfused areas in the tumor region could be demonstrated. After super‐imposing morphologic and perfusion information, subtle structural tumor inhomogeneities were depicted. Craniopharyngioma structure and perfusion defect were confirmed by T2‐weighted and perfusion‐weighted magnetic resonance imaging. Conclusion. Transcranial duplex sonography in combination with contrast specific imaging methods might be helpful to visualize perfusion defects without loss of morphological information.
A Multiple Regression Model of Combined Duplex Criteria for Detecting Threshold Carotid Stenosis and Predicting the Exact Degree of Carotid Stenosis
Authors: Hwang Chi‐Shin , Liao Kuo‐Meng , Tegeler Charles H. 
Published: November 2009

ABSTRACT Background and Purpose. Combined duplex criteria are commonly used in vascular laboratories for evaluating carotid stenosis. However, most of these combinations are empirical, and systemic validation is lacking. This study was completed using a multiple regression method to evaluate the accuracy of different combined duplex criteria for detecting threshold carotid stenosis and predicting the exact degree of carotid stenosis on angiography. Methods. Two hundred sixty‐six sets of unilateral carotid duplex and angiographic data were randomly divided into 2 sets: a derivation set and a validation set. The derivation set was used to develop a multiple logistic regression model for detecting 70% threshold carotid stenosis. Age, sex, systolic blood pressure, diastolic blood pressure, Doppler peak systolic velocity (PSV), Doppler end diastolic velocity (EDV), the systolic carotid ratio (SCR), and ophthalmic artery flow direction were tested as independent variables. A multiple linear regression model was also developed for predicting the exact degree of carotid stenosis on angiogram. The validation set was then used to evaluate the accuracy of these models. Results. According to the logistic regression strategy, the best multiple logistic regression model was as follows: probability of threshold carotid stenosis = exp(2.6 PSV ‐ 6.2)[H20907][1 + exp(2.6 PSV ‐ 6.2)]. The best linear regression model was as follows: degree of carotid stenosis = 20.2 PSV ‐7.4 EDV + 0.4 SCR + 8.5. Both models proved to be valid following an evaluation of the validation set. Conclusions. This study illustrates that Doppler parameters may be of use in predicting the exact degree of carotid stenosis and the probability of threshold carotid stenosis. This is important if duplex criteria are going to replace angiography as the only tool for selecting endarterectomy candidates.
Comparative Evaluation of Concomitant Structural and Functional Neuroimages in Rasmussen's Encephalitis
Authors: Fogarasi András , Hegyi Márta , Neuwirth Magdolna , Halász Péter , Barsi Péter , Farkas Viktor , Bognár László 
Published: November 2009

ABSTRACT Background and Purpose. Rasmussen's encephalitis (RE) is a rare condition of unknown cause characterized by intractable seizures, progressive hemiparesis, mental impairment, and inflammatory histological findings in the cortex. The primary diagnosis is based on biopsy to confirm the typical clinical, electroencephalography, and brain imaging findings. The main objective of this study was to compare simultaneous structural and functional neuroimages in RE. Methods. Concomitant magnetic resonance imaging and 2‐deoxy‐2‐[18F]‐fluoro‐D‐glucose positron emission tomography data from the authors'series of 5 children and 8 patients described in the literature were analyzed and compared. Results. Typical early findings of RE include metabolic abnormalities (hypermetabolism and hypometabolism) starting in the frontal or temporal regions or, occasionally, involving the whole hemisphere. Focal abnormalities of cerebral glucose metabolism indicate lesions sooner and depict their extent better than concomitant magnetic resonance images. The major structural abnormality remains unilateral; however, contralateral frontal lobe hypometabolism or crossed cerebellar diaschisis can be a finding of this disease. Basal ganglia involvement and whole hemispheric metabolic abnormality appear typically only after several months of disease onset. Conclusion. Concomitant structural and functional neuroimaging provide possibly complementary information in the early noninvasive workup of RE and may facilitate the early diagnosis of this rare disorder.
MRI Features of Intramedullary Spinal Cord Ependymomas
Authors: Sun Bo , Wang Chungcheng , Wang James , Liu Ali 
Published: November 2009

ABSTRACT Background and Purpose. To assess the magnetic resonance (MR) imaging characteristics of spinal intramedullary ependymomas. Methods. MR images were obtained from 60 patients with spinal intramedullary ependymomas. All patients were treated surgically, and pathological diagnoses were con‐firmed. MR images of ependymomas and associated cysts were correlated with surgical findings. Results. Among 60 cases of intramedullary ependymomas, 39 were cervical and 11 thoracic, and 10 were located at the conus medullaris and filum terminale. The lesions measured 1 to 10 vertebral segments in length along the neuraxis, with a mean length of 3.7 segments. All tumors had slightly hyperintense signals on T2‐weighted MR images. Clear tumor margins were seen in 77% of patients; 75% had uniform contrast enhancement. Rostral and caudal cysts were seen in 90% of all patients; all cysts were hypointense on T1‐weighted images and hyperintense on T2‐weighted images. The rostral cysts were 1 to 5 segments in length and caudal cysts 2 to 10 segments in length. Conclusion. Ependymomas occur most often at the upper cord rather than in the conus medullaris and filum terminale. Of the cervical and thoracic ependymomas, most were cellular or epithelial types. Papillary ependymomas occurred exclusively in the conus medullaris and filum terminale. Rostral and caudal cysts are frequently associated with intramedullary ependymomas. Clear tumor margins, more uniform enhancement, and central locations can help differentiate ependymomas from other intramedullary spinal cord tumors.
The Positions of the Patients in the Diagnosis of Patent Foramen Ovale by Transcranial Doppler
Authors: Telman Gregory , Kouperberg Efim , Sprecher Eliott , Yarnitsky David 
Published: November 2009

ABSTRACT Background and Purpose. There is no information about the optimal position of a patient for the performance of a transcranial Doppler (TCD) examination to detect patent foramen ovale (PFO). Such information is important to improving the sensitivity of the test in comparison to the gold standard of transesophageal echocardiography (TEE). Methods. Thirty‐four patients with TEE‐proved PFO were examined by contrast TCD. Examinations were done in both the sitting and supine positions in random order. Results. Eight hundred ninety‐two microemboli were recorded. Patients'positions and the sequence of testing did not affect the number of microemboli detected. Yet for each individual, 1 of the 2 positions was more sensitive. Conclusions. To improve the sensitivity of TCD in the detection of PFO, it is recommended, in the case of a first negative test, to change the patient's position for a repeated TCD examination.
Neuroimaging in Autistic Spectrum Disorder (ASD)
Authors: Sokol Deborah K. , Edwards‐Brown Mary 
Published: November 2009

ABSTRACTAutistic spectrum disorder (ASD) is a lifelong developmental disorder characterized by impairment in socialization and communication. Neuroimaging research has shown abnormalities in the frontal lobes, limbic systems, and cerebella of individuals with ASD. Recently, abnormal developmental trajectories of brain growth have been reported, with increases in brain volume (in both gray and white matter) seen in younger rather than older individuals with this disorder. Despite 30 years of research, a reliable marker for ASD has not been identified. Therefore, routine neuroimaging for individuals with ASD is not recommended.
Neuroimaging of the Complications of Epilepsy Surgery
Authors: Kelley Roger E. , DellaBadia John , Minagar Alireza , Kelley Bradford J. , Brunson Regina 
Published: November 2009

ABSTRACT Background and Purpose. Stroke‐like symptoms can be associated with the invasive evaluation and surgical resection of epileptic foci in patients with intractable epilepsy. Neurological deficits following surgical procedures for epilepsy are not uncommon, but most are relatively minor and transient. The authors investigated the neuroimaging patterns of cerebral tissue insults in patients suffering neurological deficits directly related to procedures performed to evaluate and treat intractable epilepsy. They attempted to discern potential secondary vascular insults from the not unexpected tissue loss that can be associated with various epilepsy procedures. Methods. The authors prospectively assessed 7 consecutive patients who underwent either the invasive electocortigraphic monitoring or surgical resection of epileptic foci. All had some degree of neurological deficit postoperatively. The authors evaluated for tissue injury type with postoperative computed tomography and magnetic resonance brain imaging. They also review pertinent medical literature addressing potential complications of epilepsy surgery. Results. Three patients had primarily ischemic tissue injuries, 2 had tissue loss with minor bleeding, and 1 transient deficit appeared to reflect the amount of tissue removed. Another patient had choreiform movements and gait ataxia 1 week after the procedure, but no follow‐up neuroimaging was available. The primary ischemic insults appeared to be related to vascular traction or compression or possibly vasospasm. The tissue loss/hemorrhagic insults were presumably related to tissue loss, with seepage of blood or bleeding from a resected cavernous hemangioma. No patients died, but 1 was left with a persistent, moderately severe neurological deficit. Conclusions. It is important to distinguish the not unexpected neurological deficits associated with inadvertent trauma to normal brain tissue during procedures associated with epilepsy surgery from vascular insults. Postoperative neuroimaging can be useful in this endeavor.