bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacokinetics of Echocontrast Agent Infusion in a Dog Model
Authors: Kaps M. , Seidel G. , Algermissen C. , Gerriets T. , Broillet A. 
Published: November 2009

ABSTRACTUltrasound contrast agents (UCAs) have a distinct diagnostic impact on transcranial Doppler (TCD) and duplex sonography. In addition to the properties of the UCA and ultrasound imaging modes, the duration of contrast enhancement depends on the administration mode. Infusion of UCAs may be appropriate for prolonging the diagnostically useful time of elevated Doppler intensity. Five sedated dogs were investigated by TCD during infusion with SonoVue™, a new UCA consisting of sulfur hexafluoride microbubbles. The infusion rate was varied, and the time‐intensity curves were analyzed. Infusion rate of 70 ml/h provided a stable mean level of increased Doppler intensity up to 24 to 26 dB over baseline, whereas a rate of 35 ml/h did not result in a stable plateau (range 8–19 dB over baseline [5 minutes after starting time]). The maximum increases in Doppler mean intensity (18.2 dB [35 ml/h] and 25.6 dB [70 ml/h]) were significantly different (P= .025). Pharmacokinetic analysis of SonoVue™ during inflow (by exponential functional fitting of the time‐mean intensity curves) and elimination (by linear regression analysis) revealed no dose‐related differences. This study demonstrated a dose‐dependent level of increased Doppler mean intensity within the brain circulation during infusion of SonoVue™. Unlike the bell‐shaped course of Doppler signal enhancement seen after bolus injection, infusion generates a stable plateau, which is an important prerequisite for more advanced contrast applications.
Selective Arterial Distribution of Cerebral Hyperperfusion in Fabry Disease
Authors: Moore David F. , Herscovitch Peter , Schiffmann Raphael 
Published: November 2009

ABSTRACTFabry disease is an X‐linked recessive deficiency of lysosomal α‐galactosidase A associated with an increased risk of early onset cerebrovascular disease. The disorder is reported to affect the posterior circulation predominantly. This hypothesis was investigated directly by the measurement of regional cerebral blood flow with positron emission tomography (PET). Resting regional cerebral blood flow (rCBF) in 26 hemizygous patients with Fabry disease and 10 control participants was examined using H215O and PET. Statistical parametric mapping (SPM{t}, SPM99) and PET images of patients and controls were produced. Significantly increased SPM{t} clusters were then color coded and blended with a coregistered T1 magnetic resonance imaging (MRI) template. Cerebral arterial territory maps were digitized and rescaled. Custom OpenGL and ImageVision Library C++ code was written to allow a first‐order affine transformation of the blended SPM{t} and MRI template onto the arterial territory map. The affine transformation was constrained by choosing corresponding cerebral landmark “tie points” between the SPM{t}∪ MRI template images and the cerebral arterial territory maps. The data demonstrated that the posterior circulation is the predominant arterial territory with a significantly increased rCBF in Fabry disease. No arterial distribution had a decreased rCBF.
Human Brain Temperature In Vivo: Lack of Heating During Color Transcranial Doppler Ultrasonography
Authors: Mariak Z. , Krejza J. , Swiercz M. , Lyson T. , Lewko J. 
Published: November 2009

ABSTRACTThis study was undertaken to assess the effect of ultrasound on human brain temperature in vivo. The investigation consisted of direct recording of intracranial temperature during color transcranial Doppler (TCD) sonography in a neurosurgical patient. The temperature was recorded from 3 thermocouples. One was implanted together with an intracranial pressure sensor into a surgically reduced intraparenchymal hematoma, the second was placed within the subdural space close to the temporal acoustic window, and the third was located extracranially at the outer surface of the temporal bone. Tympanic temperatures were also measured to give an approximation of global brain temperature. A 2.5‐MHz transducer was used, and the system settings were as follows: spatial peak temporal average intensity = 234 mW/cm2in B‐mode at a maximum power of 32.3 mW and 2132 mW/cm2in Doppler mode at a maximum power of 149.3 mW. Neither increase in the intraparenchymal brain temperature nor increase in the temperature at the bone/soft tissue interface was observed during 30 minutes of insonation. The ipsilateral tympanic temperature increased by only 0.06°C, and this value may be regarded as a measure of the overall increase in brain temperature. Passive cooling effect produced by the transducer, which was at ambient temperature, was found to reach the brain surface and to surpass any possible heating caused by the ultrasound. The results indicate that no noticeable increases in human brain temperature occur in response to ultrasound emitted by a color TCD device at high transmitter power settings within the diagnostic range.
High‐Resolution Magnetic Resonance Imaging Reveals Symmetric Bitemporal Cortical Necrosis After Carbon Monoxide Intoxication
Authors: Müller Notger G. , Gruber Oliver 
Published: November 2009

ABSTRACTHigh‐resolution magnetic resonance images obtained in a patient several months after carbon monoxide (CO) intoxication revealed nearly symmetric regional atrophy of both lateral temporal lobes. This pattern of cortical lesions after CO exposure has not been reported before. The patient suffered from severe cognitive deficits including a transient Klüver‐Bucy–like behavior. This report underlines the value of high‐resolution magnetic resonance imaging in chronic stages of CO intoxication in the attempt to understand the neuroanatomical bases of the observed behavior.
Discordance Between Cerebral Oxygen and Glucose Metabolism, and Hemodynamics in a Mitochondrial Encephalomyopathy, Lactic Acidosis, and Strokelike Episode Patient
Authors: Nariai Tadashi , Ohno Kikuo , Ohta Yoshihisa , Hirakawa Kimiyoshi , Ishii Kenji , Senda Michio 
Published: November 2009

ABSTRACTA patient with mitochondrial encephalomyopathy, lactic acidosis, and strokelike episode (MELAS) syndrome underwent serial measurement of cerebral blood flow with xenon computed tomography (Xe‐CBF) while presenting with strokelike episodes accompanied by a cerebral lesion. He underwent positron emission tomography (PET) measurement of the regional cerebral blood flow (PET‐CBF), metabolic rate of oxygen (CMRO2), and glucose (CMRGlu) after his symptoms and lesion disappeared. During the symptomatic period, Xe‐CBF and the Xe‐CBF response to acetazolamide loading were well preserved both in and outside the low‐density lesion. In the PET study, decreased CMRO2and increased PET‐CBF and CMRGlu were noted in the entire brain. The strokelike episodes of patients with MELAS are more likely attributed to the failure of oxygen metabolism than to a vascular accident.
Intraosseous Sacral Myxopapillary Ependymoma and the Differential Diagnosis of Sacral Tumors
Authors: Cihangiroglu Mutlu , Hartker Frederick W. , Lee Max , Sehgal Vivek , Ramsey Ruth G. 
Published: November 2009

ABSTRACTAlthough involvement of other regions of the spinal cord and brain stem is seen, myxopapillary ependymoma is most commonly found at the filum terminale or cauda equina. Less commonly, myxopapillary ependymoma may occur outside the central nervous system from direct metastatic extension of an intrathecal tumor, and rarely it may present as a primary tumor outside the thecal sac. The authors present a case of primary sacral myxopapillary ependymoma, which was first diagnosed as a chordoma. They then discuss the magnetic resonance imaging findings of this and other sacral tumors. Myxopapillary ependymoma should be considered in the differential diagnosis for a primary expansile sacral mass along with other lesions such as chordoma, aneurysmal bone cyst, and giant cell tumor.
Clinical and Magnetic Resonance Imaging Regression of Progressive Multifocal Leukoencephalopathy in an AIDS Patient After Intensive Antiretroviral Therapy
Authors: Shapiro Rita A. , Mullane Kathleen M. , Camras Lawrence , Flowers Calvin , Sutton Sarah 
Published: November 2009

ABSTRACTA 36‐year‐old homosexual man with 6 months of visual symptoms and headaches had right homonymous hemianopia, mild new learning impairment, and alexia with agraphia. The initial brain magnetic resonance imaging (MRI) scan was reported consistent with left occipital infarction. Subsequent MRI demonstrated abnormal demyelination in the subcortical white matter and deep parieto‐occipital white matter bilaterally, but primarily left. Human immunodeficiency virus testing and cerebrospinal fluid polymerase chain reaction for JC virus DNA were both positive, consistent with progressive multifocal leukoencephalopathy (PML) with AIDS. His clinical status steadily deteriorated, and MRI white matter abnormalities worsened despite high‐dose antiretroviral therapy. After the antiretroviral regimen was intensified by the addition of a protease inhibitor, rapid clinical and radiographic improvement occurred with subsequent MRI studies revealing only residual left parieto‐occipital encephalomalacia. PML in AIDS patients has been associated with a nearly uniformly poor prognosis until recent reports of improved outcomes after highly active antiretroviral therapy. This patient with PML and AIDS similarly showed a robust clinical and MRI response to intensive antiretroviral combination therapy, which has been maintained for more than 3 years.
Stroke Prevention in Sickle Cell Disease (STOP) Study Guidelines for Transcranial Doppler Testing
Authors: Nichols Fenwick T. , Jones Anne M. , Adams Robert J. 
Published: November 2009

ABSTRACTThe Stroke Prevention in Sickle Cell Disease (STOP) trial used transcranial Doppler (TCD) to screen children with sickle cell disease with no history of stroke. Children (who consented) who had time‐averaged mean of the maximum (TAMM) velocities in the middle cerebral artery and/or distal internal carotid artery were randomized to transfusion or standard. Over a slightly more than 20‐month average follow‐up, there were 11 strokes in the standard care arm and 1 stroke in the transfusion arm. This study has caused a great deal of interest in using TCD to screen children with sickle cell disease. For the STOP TCD data to be applied appropriately, it is necessary for users of TCD to understand how the STOP TCD examinations were performed, how the TCD velocities were measured, and which velocities were used. This article will review the STOP TCD scanning protocol and the reading protocol and review the TAMM velocity and how it differs from other velocity measurements.
Comparison of Transcranial Color‐Coded Sonography and Magnetic Resonance Angiography in Acute Ischemic Stroke
Authors: Lien Li‐Ming , Chen Wei‐Hung , Chen Jiunn‐Rong , Chiu Hou‐Chang , Tsai Yuh‐Feng , Choi Wai‐Man , Reynolds Patrick S. , Tegeler Charles H. 
Published: November 2009

ABSTRACT Background and Purpose. This study was designed to assess the accuracy of transcranial color‐coded sonography (TCCS) as compared to magnetic resonance angiography (MRA) for detecting intracranial arterial stenosis in patients with acute cerebral ischemia. Methods. The authors prospectively identified 120 consecutive patients admitted with acute ischemic stroke and performed both TCCS and MRA with a mean interval of 1 day. TCCS data (sampling depth, peak systolic and end diastolic angle‐corrected velocity, mean angle‐corrected velocity, and pulsatility index) for middle cerebral arteries (MCAs) were compared to MRA data and classified into 4 grades: normal (grade 1): normal caliber and signal; mild stenosis (grade 2): irregular lumen with reduced signal; severe stenosis (grade 3): absent signal in the stenotic segment (flow gap) and reconstituted distal signal; and possible occlusion (grade 4): absent signal. The cutoffs were chosen to maximize diagnostic accuracy. Results. Interobserver agreement for MRA grading resulted in a weighted‐kappa value of 0.776. The rate of poor temporal window was 37% (89/240). Doppler signals were obtained in 135 vessels, and the angle‐corrected velocities (peak systolic, end diastolic, mean) were significantly different (P= .001, P= .006, P < .001) among the MRA grades: grade 1 (100, 47, 68 cm/s), grade 2 (171, 72, 110 cm/s), grade 3 (226, 79, 134 cm/s), grade 4 (61, 26, 39 cm/s). Additionally, an angle‐corrected MCA peak systolic velocity ≥120 cm/s correlates with intracranial stenosis on MRA (grade 2 or worse) with high specificity (90.5%; 95% confidence interval = 78.5%∼96.8%) and positive predictive value (93.9%) but relatively low sensitivity (66.7%; 95% confidence interval = 61.2%∼69.5%) and negative predictive value (55.1%). Conclusion. Elevated MCA velocities on TCCS correlate with intracranial stenosis detected on MRA. An angle‐corrected peak systolic velocity ≥120 cm/s is highly specific for detecting intracranial stenosis as defined by significant MRA abnormality.
Diagnostic Value of Apparent Diffusion Coefficient Hyperintensity in Selected Patients With Acute Neurologic Deficits
Authors: Schaefer Pamela W. , Gonzalez R. Gilberto , Hunter George , Wang Bing , Koroshetz Walter J. , Schwamm Lee H. 
Published: November 2009

ABSTRACT Background and Purpose. A pattern of decreased intensity on apparent diffusion coefficient (ADC) maps is useful in the early detection of ischemic brain injury. Less information exists with regard to patients with acute neurologic deficits in whom there is abnormal conventional magnetic resonance imaging (MRI) and increased ADC intensity. Methods. The authors identified 13 patients with acute neurologic deficits who underwent diffusion MRI and had calculated ADC maps demonstrating hyperintensity in regions characterized by computed tomography hypodensity and MRI T2 hyperintensity. The initial and follow‐up imaging characteristics and clinical syndromes were recorded. Results. Clinical syndromes included hypertensive encephalopathy, posterior leukoencephalopathy, hyperperfusion following carotid endarterectomy, venous sinus thrombosis, HIV encephalopathy, and brain tumor. Diffusion‐weighted imaging (DWI) was hyperintense in 3 of 13 patients, isointense in 4 of 13 patients, heterogeneous in 3 of 13 patients, and hypointense in 3 of 13 patients. The ADC values in these regions were significantly higher than those in control regions (P < .0001). At early follow‐up, MRI abnormalities resolved completely in 3 of 13 patients and partially in 9 of 13 patients. MRI abnormalities were unchanged in 1 patient. Conclusions. In the evaluation of patients with acute neurologic deficits, ADC hyperintensity may identify a subset of patients with vasogenic edema of nonischemic etiology. Frequently, these conditions are potentially reversible if appropriately managed. DWI and conventional images alone are not sufficient to identify these neurologic conditions.
Interobserver and Intraobserver Reliability of Venous Transcranial Color‐Coded Flow Velocity Measurements
Authors: Stolz E. , Babacan S. S. , Bödeker R.‐H. , Gerriets T. , Kaps M. 
Published: November 2009

ABSTRACT Background and Purpose. Venous transcranial color‐coded duplex sonography is a new technique for noninvasive evaluation of the intracranial venous system. However, the interobserver and intraobserver reliability of this method is unclear. Methods. In 23 healthy volunteers (30 ± 7.3 years of age), the deep middle cerebral vein (dMCV), basal vein (BV), vein of Galen (VG), and straight (SRS), transverse (TS), and superior sagittal (SSS) sinuses in addition to the arterial segments of the circle of Willis were insonated through the temporal bone window on 2 consecutive days by 2 experienced examiners. The examiners were blinded to each other's results. The interobserver and intraobserver reliability was calculated using a method described by Bland and Altman, resulting in 2‐SD confidence intervals. Results. Non‐angle‐corrected and angle‐corrected systolic and end diastolic venous flow velocities (FV) were in good accordance with published normal values, ranging between 8.6 and 19.2 cm/s. The interobserver reliabilities for non‐angle‐corrected systolic FVs in the dMCV, BV, VG, SRS, and TS were ±1.8, 2.4, 2.6, 3.3, and 4.6 cm/s; for angle‐corrected systolic FVs, the interobserver reliabilities were ±2.5, 3.1, 13.9, 11.6, and 7.7 cm/s. The intraobserver reliabilities for non‐angle‐corrected systolic FVs in the dMCV, BV, VG, SRS, and TS were ±2.9, 3.2, 2.6, 3.2, and 6.1 cm/s; for angle‐corrected systolic FVs, the intraobserver reliabilities were 3.2, 3.7, 13.9, 11.6, and 7.5 cm/s. Angle correction was not attempted for the SSS. The interobserver and intraobserver reliabilities for systolic FVs in the SSS were ±3.3 and ±3.3 cm/s, respectively. Conclusions. Intracranial venous FV can be measured with a high interobserver and intraobserver reliability in healthy human subjects. Intraobserver reliability was higher for cerebral veins than for dural sinuses, predisposing them for follow‐up examinations; however, angle correction for venous FV in the VG and the SRS is not advisable.
Increased Incidence of a Midline Brain Anomaly in Patients With Nonsyndromic Clefts of the Lip and/or Palate
Authors: Nopoulos Peg , Berg Stephanie , VanDemark Duane , Richman Lynn , Canady John , Andreasen Nancy C. 
Published: November 2009

ABSTRACTBackground and Purpose. Nonsyndromic clefts of the lip and palate (CLP) are developmental craniofacial abnormalities that are often associated with cognitive dysfunction. This study was designed to evaluate, in patients with CLP, the presence of a specific midline brain anomaly (enlarged cavum septi pellucidi [CSP]) that has been shown in other developmental syndromes to be related to poor cognitive function. Methods. Brain images were obtained using magnetic resonance imaging on 49 adult men with CLP and 75 healthy controls. Size of CSP was measured using consecutive coronal images. Results. The incidence of large CSP in the CLP group was 8% (4 of 49), significantly higher than that found in the control group. In 2 of these 4 subjects, the anomaly was complete nonfusion of the septal leaflets, known as a combined CSP and cavum vergae. Furthermore, there was a significant inverse relationship of IQ and CSP in CLP patients that was not present in controls. That is, in individuals with CLP, the larger the CSP, the lower the IQ. Conclusions. Adult men with CLP have an increased prevalence of enlarged CSP. Moreover, this anomaly is directly related to cognitive deficits. This study provides further evidence that the development of the face and the development of the brain are intimately related and that defects in craniofacial development are most likely associated with defects in brain development.
Venous Infarction of Brainstem and Cerebellum
Authors: Krespi Yakup , Gurol Mahmut Edip , Coban Oguzhan , Tuncay Rezzan , Bahar Sara 
Published: November 2009

ABSTRACTThe authors describe 2 cases of posterior fossa venous infarction. A 56‐year‐old woman with essential thrombocytemia presented with fluctuating complaints of headache, nausea, vomiting, left‐sided numbness‐weakness, and dizziness and became progressively stuporous. Cranial magnetic resonance imaging (MRI) showed bilateral parasagittal frontoparietal and left cerebellar contrast‐enhancing hemorrhagic lesions. On magnetic resonance venography, the left transverse and sigmoid sinuses were occluded. The second patient, a 39‐year‐old woman, presented with acute onset of diplopia, numbness of the tongue, vertigo, and right‐sided weakness following a gestational age stillbirth. MRI revealed lesions in the right half of midbrain and pons and in the superior part of the right cerebellar hemisphere. Digital subtraction angiography showed right transverse and sigmoid sinus occlusion. The authors suggest that one should investigate the possibility of venous infarction in the presence of posterior fossa lesions that are often hemorrhagic and are not within any arterial territory distribution but respect a known venous drainage pattern. Recognition of the observed clinical and neuroimaging features can lead to earlier diagnosis and, potentially, more effective management.
Transient Crossed Cerebellar Diaschisis Following Thalamic Hemorrhage
Authors: Takasawa Masashi , Hashikawa Kazuo , Ohtsuki Toshiho , Imaizumi Masao , Oku Naohiko , Kitagawa Kazuo , Hori Masatsugu , Matsumoto Masayasu 
Published: November 2009

ABSTRACTThis report concerns a 65‐year‐old right‐handed woman with cerebral hemorrhage who presented with mild right‐sided hemiparesis. Computed tomography (CT) revealed hematoma in the left thalamus and compression of the posterior limb of the internal capsule by a brain edema surrounding the lesion. 99mTc‐hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) images obtained 4 days after onset showed hypoperfusion in the left thalamus containing a hematoma as well as contralateral cerebellar hypoperfusion to the supratentorial lesion, which is well recognized as crossed cerebellar diaschisis (CCD) after stroke. CT 14 days after the onset revealed reduction of the brain edema of the posterior limb of the internal capsule accompanied by gradual neurological improvement. SPECT obtained 14 and 28 days later showed that CCD had disappeared. In this case report, the authors discuss the disappearance of CCD due to transient edematous compression of the internal capsule following thalamic hemorrhage on serial 99mTc‐HMPAO SPECT scans. CCD was possibly caused by the lesion confined to the posterior limb of the internal capsule, which anatomically constitutes the cerebropontocerebellar pathway.
Continuous Arterial Spin Labeling Perfusion Magnetic Resonance Imaging Findings in Postpartum Vasculopathy
Authors: Chalela Julio A. , Kasner Scott E. , McGarvey Michael , Alsop David C. , Detre John A. 
Published: November 2009

ABSTRACTPostpartum vasculopathy (PPV) is a rare heterogeneous nonatherosclerotic vasculopathy that occurs in the puerperium. It occurs spontaneously but may be triggered by vasoconstrictor substances. The angiographic findings vary and include narrowing of the intracranial arteries and vasospasm. The angiographic findings and the occurrence of ischemic infarcts suggest that cerebral blood flow (CBF) is impaired in PPV. The purpose of this study is to determine CBF in patients with PPV. The authors conducted a case study of 3 patients with clinical and laboratory criteria for PPV examined during a 2‐year period. Clinical examination, computed tomography imaging, structural magnetic resonance imaging (MRI), cerebral angiography, and continuous arterial spin labeling perfusion (CASL‐PI) MRI were performed in all patients. Mean global CBF was determined, and perfusion maps were visually inspected. The CBF values and perfusion maps were correlated with the clinical symptoms and the neuroimaging findings. Three women were studied (22, 34, and 36 years old). The median time of presentation was 4 days postpartum. One presented with intracranial hemorrhage and diffuse arterial narrowing, the other 2 with stroke‐like lesions, encephalopathy, and segmental narrowing mainly in the posterior circulation. CASL‐PI was performed within 1 week of symptom onset in all 3 patients. Global mean CBF values were 51.8, 39.3, and 41.8 cc/100 g/min. Although global CBF was mildly diminished, it was above ischemic levels. Visual inspection of the CASL‐PI perfusion maps did not reveal areas of focal hypoperfusion or hyperperfusion. In this series of patients with PPV, CBF was close to normal. Although angiography often reveals diffuse arterial narrowing, the CBF values encountered in this study do not support a state of generalized or focal oligoemia. Vasomotor tone may change intermittently in patients with PPV.