American Journal of Neuroradiology

Publications in this journal

• Article: Morning Glory Disc Anomaly: Characteristic MR Imaging Findings.

  S Ellika, C D Robson, G Heidary, M J Paldino
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  ABSTRACT: Establishing the diagnosis of morning glory disc anomaly is crucial to appropriate patient treatment. Although typically made clinically, the diagnosis is not always straightforward, especially in circumstances where physical examination is limited. The goal of this study was to define the spectrum and frequency of orbital findings in a series of patients with funduscopically-confirmed morning glory disc anomaly by using MR imaging. MR imaging demonstrated 3 findings in all patients: 1) funnel-shaped morphologic pattern of the posterior optic disc with elevation of the adjacent retinal surface; 2) abnormal tissue associated with the distal intraorbital segment of the ipsilateral optic nerve, with effacement of the regional subarachnoid spaces; and 3) discontinuity of the uveoscleral coat. These findings were not observed in any of the unaffected globes of the study patients. In summary, these consistent and characteristic findings of morning glory disc anomaly should allow for accurate differentiation from other ocular anomalies and have the potential to guide appropriate management of this patient population.
  American Journal of Neuroradiology 05/2013;
• Article: Tentorial Dural Fistulas: Endovascular Management and Description of the Medial Dural-Tentorial Branch of the Superior Cerebellar Artery.

  J V Byrne, M Garcia
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  ABSTRACT: BACKGROUND AND PURPOSE:TDAVFs are uncommon causes of spontaneous intracranial hemorrhage. A retrospective review of their management was performed after repeatedly observing a previously under-recognized medial dural-tentorial branch of the SCA.MATERIALS AND METHODS:Thirteen patients were diagnosed with TDAVFs by CT/MR imaging and DSA during a 5.8-year period. Seven patients presented after intracranial hemorrhage. Twelve patients were treated endovascularly, and one, surgically.RESULTS:Eleven TDAVFs were located in the midline (7 at the falx cerebelli and 4 at the torcular), and 2 were petrotentorial. All torcular TDAVFs were associated with sinus thrombosis and showed bidirectional drainage relative to the tentorium. No sinus thrombosis was seen in the falx cerebelli subtype, which drained infratentorially only, except in 1 patient who had had unrelated surgery previously. Venous drainage was directly to cortical veins except for 1 petrotentorial and 2 torcular TDAVFs. A branch of the SCA, the medial dural-tentorial artery, was observed in 5 midline TDAVFs. Its anatomy was defined with selective angiography. Endovascular therapy resulted in a cure in 5 and subtotal occlusion in 6, and staged treatment is ongoing in 1 patient. One patient was cured after surgery.CONCLUSIONS:TDAVFs frequently cause intracranial hemorrhage and therefore warrant treatment. Endovascular therapy proved effective in this series, and arteriography was essential for understanding the various fistula subtypes and for treatment planning. We emphasize the importance of recognizing the medial dural-tentorial artery of the SCA with its characteristic course along the tentorium on angiography. This artery should be included in future anatomic descriptions of the cranial blood supply.
  American Journal of Neuroradiology 05/2013;
• Article: Coil Type Does Not Affect Angiographic Follow-Up Outcomes of Cerebral Aneurysm Coiling: A Systematic Review and Meta-Analysis.

  I Rezek, G Mousan, Z Wang, M H Murad, D F Kallmes
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  ABSTRACT: BACKGROUND AND PURPOSE:Previous studies varied in their conclusions about the superiority of second-generation coils compared with bare platinum. In this systematic review and meta-analysis, we assessed differences in reported unfavorable angiographic outcomes of cerebral aneurysms treated with coil embolization as a function of coil type.MATERIALS AND METHODS:This systematic review covered 1999-2011 through the use of Ovid MEDLINE and EMBASE. Search terms were "subarachnoid hemorrhage," "intracranial aneurysms," "endovascular treatment," and "coiling." Inclusion criteria were studies reporting >50 aneurysms with imaging follow-up. We defined "unfavorable angiographic outcome" as either "recanalization," <90% occlusion, or "incomplete occlusion" at follow-up. Rates of unfavorable outcomes were pooled through the use of random effects models and compared across various coil types. Multivariate random effects meta-regression models were used to further explore the differences in outcomes related to coil type.RESULTS:We included 82 studies, comprising 90 patient cohorts, among which, 65 (72%) used bare platinum coils, 8 (8.9%) used Matrix, 11 (12%) used HydroCoil, and 6 (6.7%) used Cerecyte. The overall unfavorable outcome rate was 19% (95% CI: 17%,21%). Unfavorable outcome rates were 20% (95% CI: 17%, 22%) for bare platinum coils, 23% (95% CI: 16%, 29%) for Matrix, 15% (95% CI: 9%, 21%) for HydroCoil, and 15% (95% CI: 7%, 23%) for Cerecyte, respectively. The difference in unfavorable outcome rates among the various coil types was not statistically significant after adjusting for baseline characteristics, including aneurysm size, rupture status, and follow-up duration.CONCLUSIONS:The rate of unfavorable angiographic outcomes was not statistically different across the major approved coil types. The quality of the evidence, however, remains low because of high heterogeneity, small sample size, and potential publication bias.
  American Journal of Neuroradiology 05/2013;
• Article: Radiation Dose for 345 CT-Guided Interlaminar Lumbar Epidural Steroid Injections.

  A L Chang, A H Schoenfeld, A L Brook, T S Miller
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  ABSTRACT: BACKGROUND AND PURPOSE:CT guidance is increasingly being used to localize the epidural space during epidural steroid injections. A common concern is that CT may be associated with significantly higher radiation doses compared with conventional fluoroscopy. The goal of this retrospective study was to determine the average dose-length product and effective dose delivered while interlaminar epidural steroid injections are performed and allow comparison with other modalities.MATERIALS AND METHODS:A total of 281 patients who had undergone 345 consecutive CT-guided epidural steroid injections of the lumbar spine were evaluated for radiation exposure. The dose-length product for each scan was derived from the CT dose index volume and scan length. Effective dose was then calculated from the dose-length product and a κ coefficient of 0.015. Procedure time was calculated from the PACS time stamp on the scout image to the last CT image of the last image series.RESULTS:The average dose-length product across all procedures was 89.6 ± 3.33 mGy·cm, which represents an effective dose of 1.34 ± 0.05 mSv. No complications from the procedure were observed, and average procedure time was 8 minutes.CONCLUSIONS:The use of a stationary table and an intermittent scanning technique allow for short procedures and doses that are significantly lower than those of conventional diagnostic CT scans. Furthermore, because CT dose index overestimates radiation dose in stationary table procedures, the actual radiation dose may be even lower than stated here.
  American Journal of Neuroradiology 05/2013;
• Article: Differences in Imaging Characteristics of HPV-Positive and HPV-Negative Oropharyngeal Cancers: A Blinded Matched-Pair Analysis.

  S C Cantrell, B W Peck, G Li, Q Wei, E M Sturgis, L E Ginsberg
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  ABSTRACT: BACKGROUND AND PURPOSE:Human papillomavirus-positive oropharyngeal cancers typically have younger age of onset, limited tobacco exposure, and more favorable prognosis than HPV-negative oropharyngeal cancers. We assessed whether HPV-positive and HPV-negative oropharyngeal cancers have consistent differences in pretreatment imaging characteristics.MATERIALS AND METHODS:A retrospective review of 136 pretreatment CT examinations of paired HPV-positive and HPV-negative oropharyngeal cancers matched for T stage, tumor subsite, and smoking status was performed with the reviewing radiologist blinded to HPV status and clinical stage. Demographic/clinical characteristics and imaging characteristics of primary lesions and metastatic nodal disease were compared by use of Fisher exact testing. The McNemar χ(2) test was used for the matched-pair analysis.RESULTS:By imaging, HPV-negative tumors were more likely to demonstrate invasion of adjacent muscle (26% versus 6%, P = .013). HPV-positive primary tumors were more likely to be enhancing and exophytic with well-defined borders, whereas HPV-negative primary tumors were more likely to be isoattenuated and demonstrate ill-defined borders, though these results were not statistically significant. HPV-positive tumors were more likely to demonstrate cystic nodal metastases than HPV-negative tumors (36% versus 9%, P = .002).CONCLUSIONS:In this matched and blinded analysis of the imaging differences between HPV-positive and HPV-negative oropharyngeal cancers, HPV-positive carcinomas often had primary lesions with well-defined borders and cystic nodal metastases, whereas HPV-negative primaries more often had poorly defined borders and invasion of adjacent muscle.
  American Journal of Neuroradiology 05/2013;
• Article: Intra-Arterial Infusion of a Glycoprotein IIb/IIIa Antagonist for the Treatment of Thromboembolism During Coil Embolization of Intracranial Aneurysm: A Comparison of Abciximab and Tirofiban.

  H W Jeong, S-C Jin
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  ABSTRACT: BACKGROUND AND PURPOSE:Abciximab and tirofiban are commonly used for the treatment of thromboembolisms that form during coiling of intracranial aneurysms; however, it is not known which of these inhibitors is safer and more effective. We report the safety and the recanalization rates for intra-arterial abciximab and intra-arterial tirofiban infusion for the treatment of thromboembolisms that form during coiling.MATERIALS AND METHODS:Between March 2004 and April 2011, 346 intracranial aneurysms were treated with coiling. Thromboembolisms developed in 22 of these patients and were treated by use of intra-arterial tirofiban (n = 11) or abciximab (n = 11) infusion.RESULTS:In the abciximab group, the thromboembolisms were completely (n = 1) or partially (n = 7) resolved in 8 cases (72.7%) at the time of the final control angiography. Complete (n = 9) or partial (n = 2) resolution was achieved in all cases at the time of follow-up angiography (<3 days after the procedure). In the tirofiban group, thromboembolisms were completely (n = 4) or partially (n = 6) resolved in 10 cases (90.9%) at the time of the final control angiography. Complete (n = 9) or partial (n = 2) resolution was observed in all cases at the time of the follow-up angiography. There were no statistically significant differences between the 2 groups with respect to thrombus resolution (final angiography, P = .311; follow-up angiography, P = .707). No hemorrhagic complications developed in either group.CONCLUSIONS:These results suggest that tirofiban is more effective than abciximab for the immediate resolution of thromboembolisms, with no statistical significance. Both intra-arterial tirofiban and abciximab exhibited similar safety and recanalization rates.
  American Journal of Neuroradiology 05/2013;
• Article: Stent-Assisted Coil Embolization of Posterior Communicating Artery Aneurysms.

  Y D Cho, W J Lee, K M Kim, H-S Kang, J E Kim, M H Han
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  ABSTRACT: BACKGROUND AND PURPOSE:Use of protective stents may not be effective in coil embolization of wide-neck aneurysms involving the posterior communicating artery. Successful implementation depends on the caliber of the vessel, its angle of origin, and the manner in which its orifice is incorporated into the aneurysm. Presented here are the results (clinical and radiographic) of coil embolization in aneurysms of the ICA-posterior communicating artery junction, variably aided by stents. The primary focus is angiographic configurations that impact stent placement.MATERIALS AND METHODS:From a prospective data repository, we retrieved records of 32 consecutive patients with 33 posterior communicating artery aneurysms, all of which were treated by stent-assisted coil embolization between June 2008 and August 2012. Outcomes were analyzed in terms of aneurysm configuration and clinical status.RESULTS:Stents were positioned entirely in the ICA (n = 26), from the ICA to the posterior communicating artery (n = 2), in the posterior communicating artery only (n = 3), and retrograde from the posterior communicating artery to the ICA terminus (n = 2). Procedure-related complications occurred in 3 patients (9.1%), but only 1 (3.0%) had mild neurologic sequelae (Glasgow Outcome Score 4). Using coil embolization, we achieved successful occlusion in 24 aneurysms (72.7%), and in 9 others, subtotal occlusion was conferred. During a mean follow-up of 15.7 ± 10.7 months, imaging of 27 aneurysms documented stable occlusion in 19 (70.4%), whereas angiography of 15 aneurysms (39.5%) disclosed 2 instances of in-stent stenosis (13.3%) and a solitary occurrence of stent migration (6.7%).CONCLUSIONS:In posterior communicating artery aneurysms, stent protection during coil embolization is feasible by adjusting the procedural strategy to accommodate differing configurations of the aneurysm and its vascular source.
  American Journal of Neuroradiology 05/2013;
• Article: Physician Quality Reporting System: 2013 Update.

  M L Loftus, P C Sanelli
  American Journal of Neuroradiology 05/2013;
• Article: Intracranial 4D Flow MRI: Toward Individualized Assessment of Arteriovenous Malformation Hemodynamics and Treatment-Induced Changes.

  S A Ansari, S Schnell, T Carroll, P Vakil, M C Hurley, C Wu, J Carr, B R Bendok, H Batjer, M Markl
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  ABSTRACT: BACKGROUND AND PURPOSE:Arteriovenous malformations are an important etiology of hemorrhagic stroke. However, current imaging modalities and risk do not provide insights into individual AVM hemodynamics and its role in pathophysiology. The aims of this study are to determine whether intracranial 4D flow MR imaging can provide insights into arteriovenous malformation hemodynamics independent of the Spetzler-Martin grade and to report the changes in flow observed during staged embolization.MATERIALS AND METHODS:Intracranial 3D blood flow was assessed in 20 patients with AVM (age = 39 ± 15 years, Spetzler-Martin grade ranging from 1-4) with the use of 4D flow MR imaging (temporal resolution = 45 ms, spatial resolution = [1.2-1.6mm](3)). AVM hemodynamics were visualized by means of time-integrated 3D pathlines depicting the AVM arterial feeding and venous draining patterns over the cardiac cycle. Analysis included the grading of feeding and draining velocities on a 3-point scale (0 = low <25 cm/s, 1 = medium <50 cm/s, 2 = high >50 cm/s). For 4 of 20 patients undergoing 4D flow MR imaging follow-up after staged embolization, peak velocities were quantified in arterial feeders, draining veins, the sagittal sinus, and contralateral arteries.RESULTS:In 50% of the cases with Spetzler-Martin grade >2, heterogeneous flow (velocity grade differences >1) was found across arteries and veins. Velocities in draining veins increased from Spetzler-Martin grade = 1 (grading = 0.5 ± 0.6) to Spetzler-Martin grade ≥3 (1.1 ± 0.6), whereas arterial velocities were similar (1.7 ± 0.6 versus 1.5 ± 0.6). In the postembolization subgroup of 4 patients, 4D flow MR imaging demonstrated successively more compact AVM and redistribution of velocities. Changes in arterial and venous velocities during treatment were highly different among individuals.CONCLUSIONS:Spetzler-Martin grade does not reflect differences in 3D AVM arterial and venous hemodynamics, and an individual assessment of AVM hemodynamics may be needed for improved lesion characterization. Four-dimensional flow MR imaging may have the potential to monitor and guide embolization treatment planning.
  American Journal of Neuroradiology 05/2013;
• Article: Geniculocalcarine Tract Disintegration after Ischemic Stroke: A Diffusion Tensor Imaging Study.

  Y Zhang, S Wan, X Zhang
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  ABSTRACT: BACKGROUND AND PURPOSE:Our aim was to investigate the disintegration of the geniculocalcarine tract by using DTI-derived parameters in cases of unilateral occipital or temporal-occipital ischemic stroke with geniculocalcarine tract involvement and to determine whether geniculocalcarine tract fibers affected by infarction and unaffected ipsilateral geniculocalcarine tract fibers have different disintegration processes. MATERIALS AND METHODS:Seventy-one patients underwent routine MR imaging and DTI of the brain. Fractional anisotropy and mean diffusivity of the geniculocalcarine tract fibers affected by infarction, ipsilateral unaffected GCT fibers, and the contralateral geniculocalcarine tract were measured and compared at 5 different time points (from <1 week to >1 year) poststroke. RESULTS:The fractional anisotropy of geniculocalcarine tract fibers affected by infarction (0.27 ± 0.06) was lower than that of contralateral GCT fibers (0.49 ± 0.03). The fractional anisotropy of geniculocalcarine tract fibers affected by infarction was not different in the first 3 weeks (P = .306). The mean diffusivity of geniculocalcarine tract fibers affected by infarction (0.53 ± 0.14) was lower than that of the contralateral GCT fibers (0.79 ± 0.07) in the first week but higher after the second week (0.95 ± 0.20 to 0.79 ± 0.06). The mean diffusivity gradually increased until it was equal to the mean diffusivity of CSF after the eighth week (2.43 ± 0.26), at which time both the fractional anisotropy and mean diffusivity values stabilized. The fractional anisotropy (0.50 ± 0.04) and mean diffusivity (0.77 ± 0.06) of the ipsilateral unaffected GCT fibers were similar to those of the contralateral GCT fibers (0.50 ± 0.03 and 0.79 ± 0.07) during the first 3 weeks. The fractional anisotropy then gradually decreased (from 0.42 ± 0.03 to 0.27 ± 0.05), while the mean diffusivity increased (from 0.95 ± 0.09 to 1.35 ± 0.11), though to a lesser degree than in the corresponding geniculocalcarine tract fibers affected by infarction. CONCLUSIONS:The geniculocalcarine tract fibers affected by infarction and the ipsilateral unaffected GCT fibers showed different disintegration processes. The progressive disintegration of geniculocalcarine tract fibers affected by infarction was stable until the eighth week poststroke. The ipsilateral unaffected GCT fibers began to disintegrate at the fourth week, but to a lesser degree than the geniculocalcarine tract fibers affected by infarction.
  American Journal of Neuroradiology 05/2013;
• Article: Neuroimaging in Patients with Abnormal Blood Glucose Levels.

  G Bathla, B Policeni, A Agarwal
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  ABSTRACT: Smooth neuronal functioning requires an uninterrupted supply of energy that is provided by glucose under normal physiologic conditions. Significant variations in plasma glucose levels, be it hypoglycemia or hyperglycemia, can present with myriad clinical manifestations and may mimic stroke. At times, the diagnosis is either not apparent or not clinically suspected. Imaging can suggest the diagnosis in unsuspected cases and can help in the assessment of the extent of neuronal damage in known cases, making it vital for the neuroradiologist to be aware of both common and atypical neuroimaging findings in hypoglycemia and hyperglycemia.
  American Journal of Neuroradiology 05/2013;
• Article: Morphologic Characteristics of Atherosclerotic Middle Cerebral Arteries on 3T High-Resolution MRI.

  X J Zhu, B Du, X Lou, F K Hui, L Ma, B W Zhen, M Jin, C X Wang, W-J Jiang
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  ABSTRACT: BACKGROUND AND PURPOSE:There are limited studies on the morphologic characteristics of MCA atherosclerotic stenosis. Our aim was to quantitatively assess the remodeling pattern and plaque distribution of atherosclerotic MCAs with 3T high-resolution MR imaging.MATERIALS AND METHODS:Eighty-seven consecutive patients with symptomatic atherosclerotic stenoses at the M1 segment of the MCA on DSA (50%-99%) were enrolled. The remodeling index was calculated as the Vessel Area at Maximal Lumen Narrowing/Reference Vessel Area. A remodeling index ≥ 1.0 was defined as positive remodeling, and a remodeling index < 1.0, as negative remodeling. Plaque distribution at the maximal lumen narrowing site was classified on the basis of the involvement of the superior, inferior, dorsal, or ventral MCA wall.RESULTS:Forty-three of 87 patients were excluded due to poor imaging quality (n = 8) or scan plane obliquity secondary to a tortuous M1 segment of the MCA or an MCA ostium lesion or angled lesion (n = 35). Of 44 patients in the final analysis, negative remodeling was found in 19 (43.2%) lesions, and positive remodeling, in 25 (56.8%) lesions. At maximal lumen narrowing sites, lesions with negative remodeling had less vessel area, wall area, and percentage of plaque burden (P < .0001) and a lower eccentricity index (P = .023), compared with lesions with positive remodeling. The plaque involved the superior and dorsal walls in 15 (34.1%) of 44 patients.CONCLUSIONS:2D high-resolution MR imaging can help assess the remodeling pattern and plaque distribution of MCA stenosis, but the imaging and postprocessing protocol for remodeling assessment needs to be improved in the tortuous course of the MCA and in MCA ostium or angled lesions.
  American Journal of Neuroradiology 05/2013;
• Article: Optimal Timing of Cerebral MRI in Preterm Infants to Predict Long-Term Neurodevelopmental Outcome: A Systematic Review.

  A Plaisier, P Govaert, M H Lequin, J Dudink
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  ABSTRACT: Advances in neonatal neuroimaging have improved detection of preterm brain injury responsible for abnormal neuromotor and cognitive development. Increasingly sophisticated MR imaging setups allow scanning during early preterm life. In this review, we investigated how brain MR imaging in preterm infants should be timed to best predict long-term outcome. Given the strong evidence that structural brain abnormalities are related to long-term neurodevelopment, MR imaging should preferably be performed at term-equivalent age. Early MR imaging is promising because it can guide early intervention studies and is indispensable in research on preterm brain injury.
  American Journal of Neuroradiology 05/2013;
• Article: Regarding "Rate and Prognosis of Patients under Conscious Sedation Requiring Emergent Intubation during Neuroendovascular Procedures"

  C G McDougall, F C Albuquerque, A F Ducruet
  American Journal of Neuroradiology 05/2013;
• Article: Dynamic MR Imaging Patterns of Cerebral Fat Embolism: A Systematic Review with Illustrative Cases.

  K-H Kuo, Y-J Pan, Y-J Lai, W-K Cheung, F-C Chang, J Jarosz
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  ABSTRACT: Different MR imaging patterns of cerebral fat embolism have been reported in the literature without a systematic review. Our goal was to describe the patterns, explore the relationship between disease course and the imaging patterns, and discuss the underlying mechanism. We reveal 5 distinctive MR imaging patterns: 1) scattered embolic ischemia occurring dominantly at the acute stage; 2) confluent symmetric cytotoxic edema located at the cerebral white matter, which mainly occurs at the subacute stage; 3) vasogenic edematous lesions also occurring at the subacute stage; 4) petechial hemorrhage, which persists from the acute to the chronic stage; and 5) chronic sequelae, occurring at late stage, including cerebral atrophy, demyelinating change, and sequelae of infarction or necrosis. Underlying mechanisms of these imaging patterns are further discussed. Recognition of the 5 evolving MR imaging patterns of cerebral fat embolism may result in adjustment of the appropriate management and improve the outcome.
  American Journal of Neuroradiology 05/2013;
• Article: Stent-Assisted Coiling Versus Balloon Remodeling of Wide-Neck Aneurysms: Comparison of Angiographic Outcomes.

  N Chalouhi, R M Starke, M T Koltz, P M Jabbour, S I Tjoumakaris, A S Dumont, R H Rosenwasser, S Singhal, L F Gonzalez
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  ABSTRACT: BACKGROUND AND PURPOSE:Stent-assisted coiling and balloon-assisted coiling are 2 well-established techniques for treatment of wide-neck intracranial aneurysms. A direct comparative analysis of angiographic outcomes with the 2 techniques has not been available. We compare the angiographic outcomes of wide-neck aneurysms treated with stent-assisted coiling versus balloon-assisted coiling.MATERIALS AND METHODS:A retrospective review was conducted on 101 consecutive patients treated at our institution, 69 with stent-assisted coiling and 32 with balloon-assisted coiling. Two multivariate logistic regression analyses were performed to determine predictors of aneurysm obliteration and predictors of progressive aneurysm thrombosis at follow-up.RESULTS:The 2 groups were comparable with respect to all baseline characteristics with the exception of a higher proportion of ruptured aneurysms in the balloon-assisted coiling group (65.6%) than in the stent-assisted coiling group (11.5%, P < .001). Procedural complications did not differ between the stent-assisted coiling group (6%) and the balloon-assisted coiling group (9%, P = .5). The rates of complete aneurysm occlusion (Raymond score 1) at the most recent follow-up were significantly higher for the stent-assisted coiling group (75.4%) compared with the balloon-assisted coiling group (50%, P = .01). Progressive occlusion of incompletely coiled aneurysms was noted in 76.6% of aneurysms in the stent-assisted coiling group versus 42.8% in the balloon-assisted coiling group (P = .02). Retreatment rates were significantly lower with stent-assisted coiling (4.3%) versus balloon-assisted coiling (15.6%, P = .05). In multivariate analysis, stented aneurysms independently predicted both complete aneurysm obliteration and progression of occlusion.CONCLUSIONS:Stent-assisted coiling may yield lower rates of retreatment and higher rates of aneurysm obliteration and progression of occlusion at follow-up than balloon-assisted coiling with a similar morbidity rate.
  American Journal of Neuroradiology 05/2013;
• Article: Brain MRI Findings in Neurologically Asymptomatic Patients with Infective Endocarditis.

  A Hess, I Klein, B Iung, P Lavallée, E Ilic-Habensus, Q Dornic, F Arnoult, L Mimoun, M Wolff, X Duval, J-P Laissy
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  ABSTRACT: BACKGROUND AND PURPOSE:Neurologic complications in infective endocarditis are frequent and affect patient prognosis negatively. Additionally, detection of asymptomatic lesions by MR imaging could help early management of this condition. The objective of our study was to describe MR imaging characteristics of cerebral lesions in a neurologically asymptomatic population with infective endocarditis.MATERIALS AND METHODS:One hundred nine patients at the acute phase of a definite or possible infective endocarditis according to the Duke modified criteria and without neurologic manifestations according to the NIHSS were prospectively included. Each patient underwent cerebral MR imaging and MRA within 7 days of admission.RESULTS:MR imaging showed abnormalities in 78 patients (71.5%). Acute ischemic lesions (40 patients, 37%) and cerebral microbleeds (62 patients, 57%) were the most frequent lesions. Eight patients had an acute SAH, 3 patients had brain microabscesses, 3 had a small cortical hemorrhage, and 3 had a mycotic aneurysm. Acute ischemic lesions mostly appeared as multiple small infarcts disseminated in watershed territories (25/40, 62.5%) and as lesions of different ages (21/40, 52.5%). Cerebral microbleeds were preferentially distributed in cortical areas (362/539 cerebral microbleeds, 67%). No significant correlation was found among lesions, in particular between acute ischemia and cerebral microbleeds.CONCLUSIONS:Occult cerebral lesions, in particular cerebral microbleeds and acute ischemic lesions, are frequent in infective endocarditis. The MR imaging pattern of acute small infarcts of different ages predominating in watershed territories and cortical cerebral microbleeds may represent a surrogate imaging marker of infective endocarditis.
  American Journal of Neuroradiology 05/2013;
• Article: Negative Predictive Value of Surveillance PET/CT in Head and Neck Squamous Cell Cancer.

  M McDermott, M Hughes, T Rath, J T Johnson, D E Heron, G J Kubicek, S W Kim, R L Ferris, U Duvvuri, J P Ohr, B F Branstetter
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  ABSTRACT: BACKGROUND AND PURPOSE:Optimizing the utilization of surveillance PET/CT in treated HNSCC is an area of ongoing research. Our aim was to determine the negative predictive value of PET/CT in patients with treated head and neck squamous cell cancer and to determine whether negative PET/CT reduces the need for further imaging surveillance.MATERIALS AND METHODS:We evaluated patients with treated HNSCC who underwent posttreatment surveillance PET/CT. During routine clinical readouts, scans were categorized as having negative, probably negative, probably malignant, or malignant findings. We followed patients clinically and radiographically for at least 12 months from their last PET/CT (mean, 26 months; median, 28 months; range, 12-89 months) to determine recurrence rates. All suspected recurrences underwent biopsy for confirmation.RESULTS:Five hundred twelve patients (1553 scans) were included in the study. Two hundred fourteen patients had at least 1 PET/CT with negative findings. Of the 214 patients with a scan with negative findings, 19 (9%) eventually experienced recurrence, resulting in a NPV of 91%. In addition, a subgroup of 114 patients with 2 consecutive PET/CT examinations with negative findings within a 6-month period was identified. Only 2 recurrences were found in this group, giving a NPV of 98%.CONCLUSIONS:In patients treated for HNSCC, a single PET/CT with negative findings carries a NPV of 91%, which is not adequate to defer further radiologic surveillance. Two consecutive PET/CT examinations with negative findings within a 6-month period, however, resulted in a NPV of 98%, which could obviate further radiologic imaging in the absence of clinical signs of recurrence.
  American Journal of Neuroradiology 05/2013;
• Article: Physiology-Based MR Imaging Assessment of CSF Flow at the Foramen Magnum with a Valsalva Maneuver.

  R A Bhadelia, N Madan, Y Zhao, M E Wagshul, C Heilman, J P Butler, S Patz
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  ABSTRACT: BACKGROUND AND PURPOSE:MR imaging is currently not used to evaluate CSF flow changes due to short-lasting physiological maneuvers. The purpose of this study was to evaluate the ability of MR imaging to assess the CSF flow response to a Valsalva maneuver in healthy participants.MATERIALS AND METHODS:A cardiac-gated fast cine-PC sequence with ≤15-second acquisition time was used to assess CSF flow in 8 healthy participants at the foramen magnum at rest, during, and immediately after a controlled Valsalva maneuver. CSF mean displacement volume VCSF during the cardiac cycle and CSF flow waveform App were determined. A work-in-progress real-time pencil-beam imaging method with temporal resolution ≤56 ms was used to scan 2 participants for 90 seconds during which resting, Valsalva, and post-Valsalva CSF flow, respiration, and HR were continuously recorded. Results were qualitatively compared with invasive craniospinal differential pressure measurements from the literature.RESULTS:Both methods showed 1) a decrease from baseline in VCSF and App during Valsalva and 2) an increase in VCSF and App immediately after Valsalva compared with values measured both at rest and during Valsalva. Whereas fast cine-PC produced a single CSF flow waveform that is an average over many cardiac cycles, pencil-beam imaging depicted waveforms for each heartbeat and was able to capture many dynamic features of CSF flow, including transients synchronized with the Valsalva maneuver.CONCLUSIONS:Both fast cine-PC and pencil-beam imaging demonstrated expected changes in CSF flow with Valsalva maneuver in healthy participants. The real-time capability of pencil-beam imaging may be necessary to detect Valsalva-related transient CSF flow obstruction in patients with pathologic conditions such as Chiari I malformation.
  American Journal of Neuroradiology 04/2013;
• Article: Distant and Delayed (>7 Days) Hemorrhage after Treatment by Flow-Diverter Stents in Intracranial Aneurysms: A Rare but Potentially Serious Complication.

  F Clarençon, F Di Maria, J Chiras, N-A Sourour, A Biondi
  American Journal of Neuroradiology 04/2013;