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American Society of Neuroradiology

Publications in this journal

• Inherited Cerebellar Ataxia in Childhood: A Pattern-Recognition Approach Using Brain MRI.

  Authors: L Vedolin, G Gonzalez, C F Souza, C Lourenço, A J Barkovich

  AJNR. American journal of neuroradiology.

  SUMMARY:Ataxia is the principal symptom of many common neurologic diseases in childhood. Ataxias caused by dysfunction of the cerebellum occur in acute, intermittent, and progressive disorders. MostSUMMARY:Ataxia is the principal symptom of many common neurologic diseases in childhood. Ataxias caused by dysfunction of the cerebellum occur in acute, intermittent, and progressive disorders. Most of the chronic progressive processes are secondary to degenerative and metabolic diseases. In addition, congenital malformation of the midbrain and hindbrain can also be present, with posterior fossa symptoms related to ataxia. Brain MR imaging is the most accurate imaging technique to investigate these patients, and imaging abnormalities include size, shape, and/or signal of the brain stem and/or cerebellum. Supratentorial and cord lesions are also common. This review will discuss a pattern-recognition approach to inherited cerebellar ataxia in childhood. The purpose is to provide a comprehensive discussion that ultimately could help neuroradiologists better manage this important topic in pediatric neurology.

• Perspectives.

  Authors: M Castillo

  AJNR. American journal of neuroradiology.

• MR Imaging of Congenital or Developmental Neuropathic Strabismus: Common and Uncommon Findings.

  Authors: E Kim, J H Kim, J M Hwang, B S Choi, C Jung

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:High-resolution MR imaging enables direct imaging of the ocular motor nerves. The aim of this study was to assess the various causes of congenital or developmental neuropathicBACKGROUND AND PURPOSE:High-resolution MR imaging enables direct imaging of the ocular motor nerves. The aim of this study was to assess the various causes of congenital or developmental neuropathic strabismus by using high-resolution MR imaging.MATERIALS AND METHODS:High-resolution MR imaging was performed to evaluate the ocular motor nerves (CNIII, CNIV, CNVI) in 247 consecutive patients with suspected congenital or developmental neuropathic strabismus. These MR images, along with those obtained from conventional MR imaging of the brain and the orbit, were evaluated.RESULTS:MR imaging abnormalities were found in 112 patients: ocular motor nerve abnormalities in 98 patients (88%), orbital abnormalities in 9 patients (8%), and brain abnormalities in 5 patients (4%). Ocular motor nerve abnormalities were CNIV aplasia (63%), CNVI aplasia or hypoplasia (21%), CNIII aplasia or hypoplasia (3%), and combined CNIII aplasia and CNVI hypoplasia (1%). Orbital abnormalities were EOM hypoplasia (7%), EOM hypertrophy (1%), and fibrotic mass (1%). Brain abnormalities were periventricular leukomalacia (4%) and periventricular heterotopia (1%).CONCLUSIONS:Various MR imaging abnormalities were associated with congenital and developmental neuropathic strabismus. The most common abnormality was CNIV aplasia.

• Effect of Cilostazol in Preventing Restenosis after Carotid Artery Stenting Using the Carotid Wallstent: A Multicenter Retrospective Study.

  Authors: K Takayama, T Taoka, H Nakagawa, K Myouchin, T Wada, M Sakamoto, K Furuichi, S Iwasaki, S Kurokawa, K Kichikawa

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Restenosis after CAS is a postoperative problem, with a reported frequency of approximately 2%-8%. However differences in stent design, procedure, and the antiplatelet agentBACKGROUND AND PURPOSE:Restenosis after CAS is a postoperative problem, with a reported frequency of approximately 2%-8%. However differences in stent design, procedure, and the antiplatelet agent appear to affect the incidence of restenosis. We assessed the frequency of restenosis and the effect of the antiplatelet agent CLZ in preventing restenosis after CAS by the standard procedure using the CWS.MATERIALS AND METHODS:Between May 2010 and October 2011, 62 lesions in 60 consecutive patients underwent CAS using the CWS at 4 medical institutions, and all patients were followed clinically and assessed by sonography, 3D-CTA, or angiography at 3 and 6 months postoperatively. stenosis. The incidence of restenosis and the variation in the ≥50% stenosis. The incidence of restenosis and the variation in the incidence of restenosis by the difference in type of antiplatelet agent between the CLZ group (n = 30; 32; aspirin, 100 mg, and clopidogrel, (n = 32; aspirin, 100 mg, and clopidogrel, 75 mg [n = 29]; or ticlopidine, 100 mg [n = 2] or 200 mg [n = 1]) were retrospectively investigated. Two antiplatelet agents were given starting 1 week preoperatively until at least 3 months postoperatively.RESULTS:Restenosis occurred in 5 patients (8.3%), but all were cases of asymptomatic lesions in the follow-up period. All 5 patients with restenosis were in the non-CLZ group, with no cases of restenosis in the CLZ group; the difference was significant (P = .0239).CONCLUSIONS:The restenosis rate after CAS by using the CWS was 8.3%. CLZ was associated with significant inhibition of restenosis.

• Therapeutic Hypothermia for Neonatal Encephalopathy Results in Improved Microstructure and Metabolism in the Deep Gray Nuclei.

  Authors: S L Bonifacio, A Saporta, H C Glass, P Lee, D V Glidden, D M Ferriero, A J Barkovich, D Xu

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Therapeutic hypothermia has reduced morbidity and mortality and is associated with a lower burden of lesions on conventional imaging in NE. However, its effects on brainBACKGROUND AND PURPOSE:Therapeutic hypothermia has reduced morbidity and mortality and is associated with a lower burden of lesions on conventional imaging in NE. However, its effects on brain microstructure and metabolism have not been fully characterized. We hypothesized that therapeutic hypothermia improves measures of brain microstructure and metabolism.MATERIALS AND METHODS:Forty-one neonates with moderate/severe NE (29 treated with hypothermia, 12 nontreated) and 12 healthy neonates underwent MR imaging, DTI, and (1)H-MR spectroscopy. MR imaging scans were scored by the predominant pattern of brain injury: normal, watershed, and BG/thalamus. ADC, FA, Lac:NAA, and NAA:Cho values from bilateral BG and thalamus ROIs were averaged. T test and linear regression analysis were used to determine the association between hypothermia and MR imaging quantitative measures.RESULTS:Conventional MR imaging findings were normal in 41% of treated neonates; all nontreated neonates had brain injury. Values of MR imaging metrics were closer to normal in treated neonates compared with nontreated neonates: ADC was 63% higher in the BG and 116% higher in the thalamus (both P < .05), and Lac:NAA was 76% lower (P = .04) in the BG. Treated neonates with normal MR imaging findings had normal (1)H-MR spectroscopy metabolites, and ADC was higher by 35% in the thalamus (P = .03) compared with healthy neonates.CONCLUSIONS:Therapeutic hypothermia may reduce disturbances of brain metabolism and preserve its microstructure in the setting of NE, possibly by minimizing cytotoxic edema and cell death. Long-term follow-up studies are required to determine whether early post-treatment DTI and (1)H-MR spectroscopy will be useful biomarkers of treatment response.

• Clinical Standardized fMRI Reveals Altered Language Lateralization in Brain Tumor Patients.

  Authors: S Partovi, B Jacobi, N Rapps, L Zipp, S Karimi, F Rengier, J K Lyo, C Stippich

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Brain tumors affecting language-relevant areas may influence language lateralization. The purpose of this study was to systematically investigate language lateralization inBACKGROUND AND PURPOSE:Brain tumors affecting language-relevant areas may influence language lateralization. The purpose of this study was to systematically investigate language lateralization in brain tumor patients using clinical language fMRI, comparing the results with a group of healthy volunteers.MATERIALS AND METHODS:Fifty-seven strictly right-handed patients with left-hemispheric-space intracranial masses (mainly neoplastic) affecting either the Broca area (n = 19) or Wernicke area (n = 38) were prospectively enrolled in this study. Fourteen healthy volunteers served as a control group. Standardized clinical language fMRI, using visually triggered sentence- and word-generation paradigms, was performed on a 1.5T MR scanner. Semiautomated analyses of all functional data were conducted on an individual basis using BrainVoyager. A regional lateralization index was calculated for Broca and Wernicke areas separately versus their corresponding right-hemisphere homologs.RESULTS:In masses affecting the Broca area, a significant decrease in the lateralization index was found when performing word generation (P = .0017), whereas when applying sentence generation, the decrease did not reach statistical significance (P = .851). Masses affecting the Wernicke area induced a significant decrease of the lateralization index when performing sentence generation (P = .0007), whereas when applying word generation, the decrease was not statistically significant (P = .310).CONCLUSIONS:Clinical language fMRI was feasible for patients with brain tumors and provided relevant presurgical information by localizing essential language areas and determining language dominance. A significant effect of the brain masses on language lateralization was observed, with a shift toward the contralesional, nondominant hemisphere. This may reflect compensatory mechanisms of the brain to maintain communicative abilities.

• White Matter Damage in Asymptomatic Patients with Sickle Cell Anemia: Screening with Diffusion Tensor Imaging.

  Authors: B Sun, R C Brown, L Hayes, T G Burns, J Huamani, D J Bearden, R A Jones

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Ischemic injury to the brain is a common complication of SCA. To better understand the neurologic impact of SCA, TBSS were applied to DTI data to investigate white matterBACKGROUND AND PURPOSE:Ischemic injury to the brain is a common complication of SCA. To better understand the neurologic impact of SCA, TBSS were applied to DTI data to investigate white matter injuries in pediatric patients with SCA.MATERIALS AND METHODS:TBSS comparisons of a range of anisotropy and diffusion measures were carried out between age- and background-matched population groups: patients with SCA with no visible lesions, patients with SCA with mild gliosis, and normal controls.RESULTS:TBSS analysis revealed that both SCA populations exhibited reduced anisotropy and increased diffusivity compared with normal controls in multiple brain regions, including the corpus callosum and centrum semiovale. Furthermore, the results suggest that the severity of SCA is positively correlated with the white matter changes in the corpus callosum.CONCLUSIONS:The study demonstrates that TBSS is a viable technique in detecting subtle white matter damage in patients with SCA whose conventional anatomic MR imaging scans show no, or minimal, abnormalities and has the potential to evaluate the neurologic impact of the treatment of SCA.

• CT-Guided Lumbar Nerve Root Injections: Are We Using the Correct Radiation Dose Settings?

  Authors: J S Schauberger, P G Kranz, K Roy Choudhury, J D Eastwood, L Gray, J K Hoang

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Selecting a lower tube current for CT fluoroscopic spine injections is a method of radiation dose reduction. Ideally tube current should be tailored to the patient's bodyBACKGROUND AND PURPOSE:Selecting a lower tube current for CT fluoroscopic spine injections is a method of radiation dose reduction. Ideally tube current should be tailored to the patient's body habitus, but a greater influence on tube current may be the proceduralist's personal preference. The purpose of this study was to compare tube current and fluoroscopy time of different proceduralists for lumbar spine CT-guided selective nerve root blocks, and to correlate image quality to patient diameter and tube current.MATERIALS AND METHODS:Eighty CT-guided SNRBs performed by 4 proceduralists were retrospectively reviewed for tube current and fluoroscopy time. Patient body habitus was evaluated by measuring anteroposterior diameters on scout images. Image quality was evaluated objectively and subjectively: noise was measured in the psoas muscle and images were graded on a 3-point scale.RESULTS:The mean tube current was 59 ± 20 mA and mean fluoroscopy time was 10.4 ± 7.5 seconds. The mean tube current between proceduralists differed by almost 2-fold, and there was greater than 2-fold difference in mean fluoroscopy time (P < .0001 and .01, respectively). Mean AP body size was 27 ± 5 cm. When categoric data of tube current and AP diameter were analyzed, only AP diameter was a statistically significant variable influencing image noise (P = .009). Twenty of 23 patients with AP diameter ≤30 cm had adequate to excellent image quality, even with lower tube current of ≤40 mA.CONCLUSIONS:Wide variability in tube current selection between proceduralists calls for a more objective method of selecting tube current to minimize radiation dose. Body size, measured by AP diameter, had the greatest influence on image quality. This could be used to identify patients for lower tube current selection.

• Metabolic Response of Glioblastoma to Superselective Intra-Arterial Cerebral Infusion of Bevacizumab: A Proton Magnetic Resonance Spectroscopic Imaging Study.

  Authors: J Y Jeon, I Kovanlikaya, J A Boockvar, X Mao, B Shin, J K Burkhardt, K Kesavabhotla, P Christos, H Riina, D C Shungu, A J Tsiouris

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:SIACI of bevacizumab has emerged as a promising novel therapy in the treatment of recurrent GB. This study assessed the potential of (1)H-MRS as an adjunctive technique inBACKGROUND AND PURPOSE:SIACI of bevacizumab has emerged as a promising novel therapy in the treatment of recurrent GB. This study assessed the potential of (1)H-MRS as an adjunctive technique in detecting metabolic changes reflective of antiproliferative effects of targeted infusion of bevacizumab in the treatment of GB.MATERIALS AND METHODS:Eighteen patients enrolled in a phase I/II study of SIACI of bevacizumab for treatment of recurrent GB were included. Concurrent MR imaging and (1)H-MRS scans were performed before and after treatment. Five distinct morphologic ROIs were evaluated for structural and metabolic changes on MR imaging and (1)H-MRS, which included enhancing, nonenhancing T2 hyperintense signal abnormality, and multiple control regions. Pre- and post-SIACI of bevacizumab peak areas for NAA, tCho, tCr, as well as tCho/tCr and tCho/NAA ratios, were derived for all 5 ROIs and compared using the Wilcoxon signed-rank test.RESULTS:A significant median decrease of 25.99% (range -55.76 to 123.94; P = .006) in tCho/NAA was found post-SIACI of bevacizumab relative to pretreatment values in regions of enhancing disease. A trend-level significant median decrease of 6.45% (range -23.71 to 37.67; P = .06) was noted in tCho/NAA posttreatment in regions of nonenhancing T2-hyperintense signal abnormality.CONCLUSIONS:The results of this (1)H-MRS analysis suggest that GB treatment with SIACI of bevacizumab may be associated with a direct antiproliferative effect, as demonstrated by significant reductions of tCho/NAA after the intervention.

• Neuroradiology Back to the Future: Spine Imaging.

  Authors: E G Hoeffner, S K Mukherji, A Srinivasan, D J Quint

  AJNR. American journal of neuroradiology.

  SUMMARY:Although radiography of the spine began shortly after Roentgen's discovery in 1895, there was little written in the medical literature about spine imaging until nearly 25 years later with theSUMMARY:Although radiography of the spine began shortly after Roentgen's discovery in 1895, there was little written in the medical literature about spine imaging until nearly 25 years later with the development of myelography, first by using air and then a variety of positive contrast agents. The history of spine imaging before CT and MR imaging is, in large part, a history of the development of contrast agents for intrathecal use. The advent of CT and, more important, MR imaging revolutionized spine imaging. The spinal cord and its surrounding structures could now be noninvasively visualized in great detail. In situations in which myelography is still necessary, advances in contrast agents have made the procedure less painful with fewer side effects. In this historical review, we will trace the evolution of spine imaging that has led to less invasive techniques for the evaluation of the spine and its contents and has resulted in more rapid, more specific diagnosis, therapy, and improved outcomes.

• Update on a Patient with Superficial Siderosis on Deferiprone.

  Authors: M Levy, R H Llinas

  AJNR. American journal of neuroradiology.

• A Comparison Between Volumetric Data Generated by Voxel-Based Morphometry and Manual Parcellation of Multimodal Regions of the Frontal Lobe.

  Authors: O Lindberg, A Manzouri, E Westman, L O Wahlund

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Volumetric measurements on structural MR images are an established method to investigate pathology-related volume changes in cortex. Manual volumetric methods have sometimesBACKGROUND AND PURPOSE:Volumetric measurements on structural MR images are an established method to investigate pathology-related volume changes in cortex. Manual volumetric methods have sometimes been referred to as the reference standard for quality control of automatic volumetric methods. While some automatic methods, like VBM, may rely on a template, manual methods use sulci as indirect landmarks for the subdivision of cortex. The purpose of this study was to compare volumetric data generated by MM and VBM on 4 multimodal regions in the frontal lobe.MATERIALS AND METHODS:We investigated 4 multimodal frontocortical regions by MM and VBM in patients with frontotemporal lobar degeneration and Alzheimer disease and controls.RESULTS:MM and VBM results were highly correlated for dorsolateral prefrontal cortex, orbitofrontal cortex, and hippocampus, but not for the dorsal and rostral anterior cingulate. VBM results were more consistent with results from previous studies on cingulate in frontotemporal lobar degeneration. Our results may potentially be explained by 2 factors. First, the volume of small cortical regions may be more affected by anatomic variability than large regions in the MM. Second, it has been shown that the location of multimodal cytoarchitectonic areas, such as the cingulate cortex, may be difficult to predict by the appearance of sulci and gyri.CONCLUSIONS:While both VBM and the MM may do equally poorly in predicting cytoarchitecture, the MM may add additional unrelated variance caused by anatomic variability. Thus, paradoxically, the higher anatomic precision of the MM may potentially cause a weaker relation to cytoarchitecture.

• Normal Ossification Patterns of Atlas and Axis: A CT Study.

  Authors: G M Karwacki, J F Schneider

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Development of the CVJ is a complex process rarely analyzed by CT. Cartilaginous remnants within the atlas and axis have been shown to variably persist throughout childhood andBACKGROUND AND PURPOSE:Development of the CVJ is a complex process rarely analyzed by CT. Cartilaginous remnants within the atlas and axis have been shown to variably persist throughout childhood and may be mistaken for fractures. The purpose of this study was to better estimate the fusion timeline of the synchondroses at the CVJ.MATERIALS AND METHODS:We retrospectively reviewed singular CT scans in 550 children without known skeletal dysplasia or maturation delay (from neonate to 17 years) and analyzed the ossification of atlas and axis. Normal closing age for synchondroses was defined as soon as a complete ossification rate of 80% or more per age category was achieved.RESULTS:No separate OC was observed in 38 of 230 incompletely ossified AAAs, whereas single, bipartite, or multiple OCs were observed in, respectively, 196, 86, and 16 of 298 AAAs in which OCs could be identified. Synchondroses at the AAA closed after 12 years (range 4.5-17 years). Posterior midline synchondrosis of the atlas closed after 4 years (range 2-13 years). The axis ossified from 6 OCs and 4 synchondroses. Subdental and neurocentral synchondroses closed simultaneously after 9 years (range 7-9.5 years). Apicodental synchondrosis and chondrum terminale were completely ossified after 10.5 years (range 5.5-13.5 years).CONCLUSIONS:Analysis of the CVJ using triplanar CT reconstructions allows secure identification of characteristic developmental features of the atlas and axis, and helps to separate normal variants from true osseous lesions.

• Cerebral White Matter Disruption in Creutzfeldt-Jakob Disease.

  Authors: H Lee, O S Cohen, H Rosenmann, C Hoffmann, P B Kingsley, A D Korczyn, J Chapman, I Prohovnik

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Human prion diseases are known to cause gray matter degeneration in specific cerebral structures, but evidence for white matter involvement is scarce. We used DTI to test theBACKGROUND AND PURPOSE:Human prion diseases are known to cause gray matter degeneration in specific cerebral structures, but evidence for white matter involvement is scarce. We used DTI to test the hypothesis that white matter integrity is disrupted in human CJD during the early stages of the disease.MATERIALS AND METHODS:Twenty-one patients with the E200K variant of CJD and 19 controls participated in DTI studies conducted on a 1.5T MR imaging scanner. The data were quantitatively analyzed and mapped with a voxelwise TBSS method.RESULTS:We found significant reductions of FA in patients with CJD in distinct and functionally relevant white matter pathways, including the corticospinal tract, internal capsule, external capsule, fornix, and posterior thalamic radiation. Moreover, these FA deficits increased with disease duration, and were mainly determined by increase of radial diffusivity, suggesting elevated permeability of axonal membranes.CONCLUSIONS:The findings suggest that some of the symptoms of CJD may be caused by a functional dysconnection syndrome, and that the leukoencephalopathy is progressive and detectable fairly early in the course of the disease.

• Comparison of Phase-Contrast MR Imaging and Endovascular Sonography for Intracranial Blood Flow Velocity Measurements.

  Authors: J J Schneiders, S P Ferns, P van Ooij, M Siebes, A J Nederveen, R van den Berg, J van Lieshout, G Jansen, E Vanbavel, C B Majoie

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Local hemodynamic information may help to stratify rupture risk of cerebral aneurysms. Patient-specific modeling of cerebral hemodynamics requires accurate data on BFV inBACKGROUND AND PURPOSE:Local hemodynamic information may help to stratify rupture risk of cerebral aneurysms. Patient-specific modeling of cerebral hemodynamics requires accurate data on BFV in perianeurysmal arteries as boundary conditions for CFD. The aim was to compare the BFV measured with PC-MR imaging with that obtained by using intra-arterial Doppler sonography and to determine interpatient variation in intracranial BFV.MATERIALS AND METHODS:In 10 patients with unruptured intracranial aneurysms, BFV was measured in the cavernous ICA with PC-MR imaging in conscious patients before treatment, and measured by using an intra-arterial Doppler sonography wire when the patient was anesthetized with either propofol (6 patients) or sevoflurane (4 patients).RESULTS:Both techniques identified a pulsatile blood flow pattern in cerebral arteries. PSV differed >50 cm/s between patients. A mean velocity of 41.3 cm/s (95% CI, 39.3-43.3) was measured with PC-MR imaging. With intra-arterial Doppler sonography, a mean velocity of 29.3 cm/s (95% CI, 25.8-32.8) was measured with the patient under propofol-based intravenous anesthesia. In patients under sevoflurane-based inhaled anesthesia, a mean velocity of 44.9 cm/s (95% CI, 40.6-49.3) was measured.CONCLUSIONS:We showed large differences in BFV between patients, emphasizing the importance of using patient-specific hemodynamic boundary conditions in CFD. PC-MR imaging measurements of BFV in conscious patients were comparable with those obtained with the intra-arterial Doppler sonography when the patient was anesthetized with a sevoflurane-based inhaled anesthetic.

• MR Imaging: An Increasingly Important Tool in the Early Diagnosis of Wernicke Encephalopathy.

  Authors: G Zuccoli, N Pipitone

  AJNR. American journal of neuroradiology.

• Motion-Compensation Techniques in Neonatal and Fetal MR Imaging.

  Authors: C Malamateniou, S J Malik, S J Counsell, J M Allsop, A K McGuinness, T Hayat, K Broadhouse, R G Nunes, A M Ederies, J V Hajnal, M A Rutherford

  AJNR. American journal of neuroradiology.

  SUMMARY:Fetal and neonatal MR imaging is increasingly used as a complementary diagnostic tool to sonography. MR imaging is an ideal technique for imaging fetuses and neonates because of the absenceSUMMARY:Fetal and neonatal MR imaging is increasingly used as a complementary diagnostic tool to sonography. MR imaging is an ideal technique for imaging fetuses and neonates because of the absence of ionizing radiation, the superior contrast of soft tissues compared with sonography, the availability of different contrast options, and the increased FOV. Motion in the normally mobile fetus and the unsettled, sleeping, or sedated neonate during a long acquisition will decrease image quality in the form of motion artifacts, hamper image interpretation, and often necessitate a repeat MR imaging to establish a diagnosis. This article reviews current techniques of motion compensation in fetal and neonatal MR imaging, including the following: 1) motion-prevention strategies (such as adequate patient preparation, patient coaching, and sedation, when required), 2) motion-artifacts minimization methods (such as fast imaging protocols, data undersampling, and motion-resistant sequences), and 3) motion-detection/correction schemes (such as navigators and self-navigated sequences, external motion-tracking devices, and postprocessing approaches) and their application in fetal and neonatal brain MR imaging. Additionally some background on the repertoire of motion of the fetal and neonatal patient and the resulting artifacts will be presented, as well as insights into future developments and emerging techniques of motion compensation.

• Severe Traumatic Head Injury: Prognostic Value of Brain Stem Injuries Detected at MRI.

  Authors: A Hilario, A Ramos, J M Millan, E Salvador, P A Gomez, M Cicuendez, R Diez-Lobato, A Lagares

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Traumatic brain injuries represent an important cause of death for young people. The main objectives of this work are to correlate brain stem injuries detected at MR imagingBACKGROUND AND PURPOSE:Traumatic brain injuries represent an important cause of death for young people. The main objectives of this work are to correlate brain stem injuries detected at MR imaging with outcome at 6 months in patients with severe TBI, and to determine which MR imaging findings could be related to a worse prognosis.MATERIALS AND METHODS:One hundred and eight patients with severe TBI were studied by MR imaging in the first 30 days after trauma. Brain stem injury was categorized as anterior or posterior, hemorrhagic or nonhemorrhagic, and unilateral or bilateral. Outcome measures were GOSE and Barthel Index 6 months postinjury. The relationship between MR imaging findings of brain stem injuries, outcome, and disability was explored by univariate analysis. Prognostic capability of MR imaging findings was also explored by calculation of sensitivity, specificity, and area under the ROC curve for poor and good outcome.RESULTS:Brain stem lesions were detected in 51 patients, of whom 66% showed a poor outcome, as expressed by the GOSE scale. Bilateral involvement was strongly associated with poor outcome (P < .05). Posterior location showed the best discriminatory capability in terms of outcome (OR 6.8, P < .05) and disability (OR 4.8, P < .01). The addition of nonhemorrhagic and anterior lesions or unilateral injuries showed the highest odds and best discriminatory capacity for good outcome.CONCLUSIONS:The prognosis worsens in direct relationship to the extent of traumatic injury. Posterior and bilateral brain stem injuries detected at MR imaging are poor prognostic signs. Nonhemorrhagic injuries showed the highest positive predictive value for good outcome.

• Subarachnoid Hemorrhage Incidence in the United States Does Not Vary with Season or Temperature.

  Authors: R J McDonald, J S McDonald, J P Bida, D F Kallmes, H J Cloft

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Previous studies have suggested seasonal variations in rates of spontaneous rupture of intracranial aneurysms, leading to potentially devastating SAH. In an effort to identifyBACKGROUND AND PURPOSE:Previous studies have suggested seasonal variations in rates of spontaneous rupture of intracranial aneurysms, leading to potentially devastating SAH. In an effort to identify a seasonal effect, variation in SAH incidence and in-hospital mortality rates were examined as they relate to admission month, temperature, and climate using HCUP's Nationwide Inpatient Sample.MATERIALS AND METHODS:Cases of nontraumatic SAH and subsequent in-hospital mortality were extracted from the 2001-2008 NIS and associated with month of occurrence, local average monthly temperatures, and USDA climate zone. Multivariate regression analysis was used to study how admission month, temperature, and climate affected SAH admission and mortality rates.RESULTS:Among 57,663,486 hospital admissions from the 2001-2008 NIS, 52,379 cases of spontaneous SAH (ICD-9-CM 430) and 13,272 cases of subsequent in-hospital mortality were identified. SAH incidence and in-hospital mortality rates were not significantly correlated with a monthly/seasonal effect (incidence, χ (2) = 2.94, P = .99; mortality, χ (2) = 6.91, P = .81). However, SAH incidence significantly varied with climate (P < .0001, zones 11 and 7) but not with temperature (P = .1453), whereas average monthly temperature and climate had no significant correlation with in-hospital mortality (temperature, P = .3005; climate, P = .0863).CONCLUSIONS:We identified no significant monthly or temperature-related effect in the incidence of SAH. Our data suggest that certain climate zones within the United States may be associated with significantly different SAH incidence, but the origins of these differences remain unclear and are probably unrelated to meteorologic variables.

• No Association Between Conventional Brain MR Imaging and Chronic Cerebrospinal Venous Insufficiency in Multiple Sclerosis.

  Authors: R Zivadinov, G Cutter, K Marr, M Ramanathan, R H B Benedict, N Bergsland, C Morgan, E Carl, D Hojnacki, E A Yeh, L Willis, M Cherneva, C Kennedy, M G Dwyer, B Weinstock-Guttman

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:CCSVI has been reported to occur at high frequency in MS. Its significance in relation to MR imaging parameters also needs to be determined, both in patients with MS and HCs.BACKGROUND AND PURPOSE:CCSVI has been reported to occur at high frequency in MS. Its significance in relation to MR imaging parameters also needs to be determined, both in patients with MS and HCs. Therefore, this study determined the associations of CCSVI and conventional MR imaging outcomes in patients with MS and in HCs.MATERIALS AND METHODS:T2, T1, and gadolinium lesion number, LV, and brain atrophy were assessed on 3T MR imaging in 301 subjects, of whom 162 had RRMS, 66 had secondary-progressive MS subtype, and 73 were HCs. CCSVI was assessed using extracranial and transcranial Doppler evaluation. The MR imaging measure differences were explored with 27 borderline cases for CCSVI, added to both the negative and positive CCSVI groups to assess sensitivity of the results of these cases.RESULTS:No significant differences between subjects with and without CCSVI were found in any of the individual diagnostic subgroups or MS disease subtypes for lesion burden and atrophy measures, independently of the CCSVI classification criteria used, except for a trend for higher T2 lesion number (irrespective of how borderline cases were classified) and lower brain volume (when borderline cases were included in the positive group) in patients with RRMS with CCSVI. No CCSVI or MR imaging differences were found between 26 HCs with, or 47 without, a familial relationship.CONCLUSIONS:CCSVI is not associated with more severe lesion burden or brain atrophy in patients with MS or in HCs.

• Reduced Diffusion in a Subset of Acute MS Lesions: A Serial Multiparametric MRI Study.

  Authors: P Eisele, K Szabo, M Griebe, C Roßmanith, A Förster, M Hennerici, A Gass

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:MRI studies have focused on newly developing MS lesions to characterize the early pathology of the disease. DWI is highly sensitive to acute and chronic tissue changes in MS.BACKGROUND AND PURPOSE:MRI studies have focused on newly developing MS lesions to characterize the early pathology of the disease. DWI is highly sensitive to acute and chronic tissue changes in MS. We characterized the development of acute MS lesions by using DWI in a multiparametric MRI protocol.MATERIALS AND METHODS:Seventy-two consecutive patients presenting with a new symptom with definite MS or a CIS suggestive of central nervous system demyelination were screened with MRI. Patients who showed an acute MRI lesion with a reduction of ADC were studied with serial MRI for up to 4 months after presentation.RESULTS:Ten of 72 screened patients who showed a lesion with a reduced ADC were each examined 4-7 times, resulting in 52 examinations in total. We identified a characteristic sequence of signal-intensity changes: 1) days 0-7: slight T2 hyperintensity and prominent ADC reduction (maximum, -66%), faint or no enhancement on postcontrast T1-weighted images; 2) days 7-10: prominent T2 hyperintensity and contrast enhancement, ADC normalization/pseudonormalization; 3) up to 4 weeks: elevated ADC values, prominent enhancement on postcontrast images; 4) after 4 weeks: partial reversibility of T2 hyperintensity, ADC elevation, and resolution of contrast enhancement.CONCLUSIONS:In a subgroup of patients with MS presenting soon after new symptom onset, a transient reduction of the ADC delineated a short and very early phase of MS lesion evolution. Subsequent pseudonormalization of the ADC occurred along with signs of the development of vasogenic edema.

• Stability in Brain Glucose Metabolism Following Brown Adipose Tissue Inactivation in Chinese Adults.

  Authors: Q Miao, X L Zhao, Q Y Zhang, Z Y Zhang, Y H Guan, H Y Ye, S Zhang, M F Zeng, C T Zuo, Y M Li

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:The thermogenesis of BAT is believed to be controlled through some pathways initiated in the brain, though the changes in brain activity among different states of BAT-positiveBACKGROUND AND PURPOSE:The thermogenesis of BAT is believed to be controlled through some pathways initiated in the brain, though the changes in brain activity among different states of BAT-positive subjects are still unclear. We hypothesized that some significant differences of regional cerebral metabolism between various groups were related to the BAT activities regardless of temperature changes.MATERIALS AND METHODS:Relative regional cerebral glucose metabolism was compared between 15 healthy subjects with activated BAT and 30 healthy controls without activated BAT by using a brain FDG-PET scan. A follow-up PET scan was performed to assess metabolic changes of the brain when BAT activity was eliminated by heat exposure.RESULTS:Compared with controls, BAT-positive subjects exhibited lower activity in the inferior parietal lobule, limbic system, and frontal lobe and higher activity in the precuneus before heat exposure. Compared with the BAT elimination status, subjects with activated BAT showed a decreased metabolism in the parietal lobe, frontal lobe, culmen, cingulate gyrus, and sublobar region. Compared with controls, BAT-positive subjects after BAT inactivation had significant hypometabolic areas in the temporal lobe and limbic lobe and hypermetabolic areas in the parietal lobe.CONCLUSIONS:Our findings illustrate that changes of regional cerebral metabolism are related to BAT activities regardless of temperature changes. This before-after controlled study supports the finding that the brain responses appear to be active in modulating the metabolic function of BAT activity.

• Analysis of Intra-Aneurysmal Flow for Cerebral Aneurysms with Cerebral Angiography.

  Authors: L-D Jou, M E Mawad

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Hemodynamics is an important factor in the development and rupture of cerebral aneurysms. Current techniques for measuring blood flow in cerebral aneurysms suffer from variousBACKGROUND AND PURPOSE:Hemodynamics is an important factor in the development and rupture of cerebral aneurysms. Current techniques for measuring blood flow in cerebral aneurysms suffer from various limitations and have not been able to address our clinical needs. A new technique has been developed for effective evaluation of intra-aneurysmal flow based on high-frame-rate cerebral angiography, especially for flow-diverters.MATERIALS AND METHODS:Six patients with 7 unruptured ICA aneurysms were imaged with a specially designed DSA protocol (a 3D DSA and a 2D DSA acquired at 30 frames/s, with a 2-mL/s contrast injection rate). Images of these cases were analyzed to determine the intra-aneurysmal flow based on the newly developed technique. Patient-specific aneurysm models were used for CFD calculation, and intra-aneurysmal flow rates were computed numerically. The intra-aneurysmal flow rates from the 2 methods were then compared.RESULTS:There is a linear relationship between intra-aneurysmal flow ratios obtained from high-frame-rate cerebral angiography and CFD calculation (R = 0.99). A high frame rate (30 frames/s) provides a better estimate of intra-aneurysmal flow than low frame rates (7.5 frames/s and 15 frames/s).CONCLUSIONS:The CFD calculation validates the estimate of intra-aneurysmal hemodynamics from cerebral angiography. The linear relationship obtained by using these 2 techniques can be used for real-time assessment of intra-aneurysmal hemodynamics for cerebral aneurysms.

• In Vivo X-Ray Digital Subtraction and CT Angiography of the Murine Cerebrovasculature Using an Intra-Arterial Route of Contrast Injection.

  Authors: G Figueiredo, H Boll, M Kramer, C Groden, M A Brockmann

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:Investigation of the anatomy, patency, and blood flow of arterial and venous vessels in small animal models of cerebral ischemia, venous thrombosis, or vasospasm is of majorBACKGROUND AND PURPOSE:Investigation of the anatomy, patency, and blood flow of arterial and venous vessels in small animal models of cerebral ischemia, venous thrombosis, or vasospasm is of major interest. However, due to their small caliber, in vivo examination of these vessels is technically challenging. Using micro-CT, we compared the feasibility of in vivo DSA and CTA of the murine cerebrovasculature using an intra-arterial route of contrast administration.MATERIALS AND METHODS:The ECA was catheterized in 5 C57BL/6J mice. During intra-arterial injection of an iodized contrast agent (30 μL/1 sec), DSA of the intra- and extracranial vessels was performed in mice breathing room air and repeated in hypoxic/hypercapnic mice. Micro-CTA was performed within 20 seconds of intra-arterial contrast injection (220 μL/20 sec). Image quality of both methods was compared. Radiation dose measurements were performed with thermoluminescence dosimeters.RESULTS:Both methods provided high-resolution images of the murine cerebrovasculature, with the smallest identifiable vessel calibers of ≤50 μm. Due to its high temporal resolution of 30 fps, DSA allowed identification of anastomoses between the ICA and ECA by detection of retrograde flow within the superficial temporal artery. Micro-CTA during intra-arterial contrast injection resulted in a reduced injection volume and a higher contrast-to-noise ratio (19.0 ± 1.0) compared with DSA (10.0 ± 1.8) or micro-CTA when using an intravenous injection route (1.3 ± 0.4).CONCLUSIONS:DSA of the murine cerebrovasculature is feasible using micro-CT and allows precise and repeated measurements of the vessel caliber, and changes of the vessel caliber, while providing relevant information on blood flow in vivo.

• Effectiveness of Mechanical Endovascular Thrombectomy in a Model System of Cerebrovascular Occlusion.

  Authors: J Y Chueh, A K Wakhloo, M J Gounis

  AJNR. American journal of neuroradiology.

  BACKGROUND AND PURPOSE:A number of thrombectomy devices are currently undergoing clinical evaluation; meanwhile, various novel devices are under investigation. The aims of this study were to quantifyBACKGROUND AND PURPOSE:A number of thrombectomy devices are currently undergoing clinical evaluation; meanwhile, various novel devices are under investigation. The aims of this study were to quantify flow restoration and the particle size distribution of the effluent pursuant to MET in an in vitro occlusion model.MATERIALS AND METHODS:The model system was composed of 3 elements: an ICA/MCA replica, a clot model with mechanical properties similar to those of thrombi found in patients at risk of stroke, and a pulsatile flow loop. Different thrombectomy mechanisms including mechanical retrieval, aspiration, and waveguide induced cavitation were used. The efficacy end points were recanalization rate and amount of flow restoration. The risk of the embolic shower was assessed to evaluate device safety.RESULTS:The recanalization rates were the following: Merci, 67%; Solitaire, 100%; Penumbra, 83%; Enterprise, 17%; and the waveguide, 0%. In experiments in which recanalization was achieved, the amount of flow restoration for the Merci, Solitaire, and Enterprise devices was 100%, 92%, and 86%, respectively. The mean sizes of generated small and large clot fragments were between 23 and 37 and 215 and 285 μm, respectively, depending on the device used. The Merci device generated the fewest number of large fragments compared with the Penumbra system (P < .05) and Solitaire (not significant).CONCLUSIONS:The risk of embolic shower was influenced by the mechanism of action for the thrombectomy device. Clinically reported recanalization rates for the Solitaire, Penumbra, and Merci devices were nearly identical in this model system, suggesting that this model may provide a predictive tool for preclinical evaluation of MET.

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