Phenylketonuria (PKU) is an inherited disorder of amino acid metabolism. Despite early dietary treatment, cognitive functioning of patients has been reported as being inferior to healthy controls. Objective of this study was to assess functional connectivity (FC) alterations in PKU in cognition-related brain networks by resting-state functional magnetic resonance imaging. We followed a hierarchical analysis approach partially based on higher criticism (HC) statistics as previously applied in a larger sister-project in fetal alcohol syndrome. After exclusions for excessive head movement, 11 female young adults with early-treated PKU (age: 27.2 ± 3.7 years) and 11 age-matched female healthy controls (age: 25.9 ± 3.8 years) were included in the analysis. We observed effects within attention networks and the default mode network, but not in fronto-parietal networks, at the HC-based intermediate analysis level. No between-network FC differences were found. In the most detailed analysis level, we could not identify single affected functional connections. Despite statistical power limitations in this small sample, these preliminary findings are in line with previously reported FC alterations in PKU and the cognitive profile in young adults with PKU, particularly the still uncertain notion that cognitive control deficits might become less pronounced when PKU patients reach adulthood.

Background/Objectives: Lead acrylic shields (LASs) enhance radiation protection, with variation of their usage among different specialties. This prospective multicentric observational study aimed to explore patterns of ocular radiation exposure and LAS usage among interventionalists from different disciplines and to assess behavioral dose changes in a longitudinally monitored subgroup. Methods: From July 2019 to July 2020, ocular doses (protected and unprotected) were measured in 15 interventionalists from four specialties (radiology, neuroradiology, cardiology and vascular surgery) across 2286 procedures using thermoluminescent dosimeters. Procedure type, operator position, total body dose, fluoroscopy time, dose area product, LAS usage and dose exceedances were documented. Ocular doses of five interventionalists, who participated in our previous study, allowed a longitudinal comparison of radiation doses and protective behavior. Results: Cumulative annual unprotected ocular doses ranged from 0 to 59 mSv, with five participants exceeding the annual limit of 20 mSv, whereas protected doses (0 to 18 mSv) remained within the limits. Procedural LAS usage was seen in 89% of radiologists and 82% of vascular surgeons. Participants with 100% LAS usage recorded minimal measurable ocular doses, whereas lower LAS compliance resulted in higher ocular doses. Longitudinal subgroup data analyses showed a decrease in ocular dose per procedure in all five participants, suggesting a potential learning effect, without statistical significance. Conclusions: Unprotected ocular doses exceeded the annual occupational eye lens dose limit in several participants, whereas protected doses remained within recommended limits in all participants. No specialty demonstrated universally lower ocular doses, while consistent LAS use proved highly effective in reducing the dose in all groups. Longitudinal findings suggest that structured dose monitoring and repeated training may support behavioral improvements in radiation protection over time.

BACKGROUND AND IMPORTANCE:This case highlights the effectiveness of endovascular balloon dilatation (percutaneous transluminal angioplasty (PTA)) for treating vasospasm in a radial artery (RA) bypass graft from the internal carotid artery to the M2 branch of the middle cerebral artery in a patient with severe subarachnoid hemorrhage. CLINICAL PRESENTATION:A 69-year-old woman with severe subarachnoid hemorrhage due to a ruptured giant aneurysm in the ophthalmic segment of the right internal carotid artery underwent an extracranial-intracranial high-flow bypass with a RA graft, followed by trapping of the aneurysm. During her intensive care unit stay, vasospasms developed primarily in the intracranial radial graft and M2 branches. These spasms showed only minimal improvement after standard care and intra-arterial vasospasmolysis with nimodipine. Thus, after systemic anticoagulation, balloon PTA was performed, treating both the intracranial and extracranial sections of the graft, including areas near the anastomosis. The procedure was complication-free, with immediate morphological success and significant improvement in perfusion to the middle cerebral artery territory. CONCLUSION:Endovascular balloon PTA should be considered a rescue measure for vasospasm in extracranial-intracranial bypasses, particularly with RA grafts post-SAH. Owing to its muscular structure, the RA graft is especially prone to spasm, potentially compromising graft patency. When pharmacological treatments fail, balloon PTA offers a targeted intervention to restore vessel caliber, stabilizing blood flow and preventing ischemic complications, thus supporting the bypass's long-term success.

Visualizations are vital for communicating scientific results. Historically, neuroimaging figures have only depicted regions that surpass a given statistical threshold. This practice substantially biases interpretation of the results and subsequent meta-analyses, particularly towards non-reproducibility. Here we advocate for a "transparent thresholding" approach that not only highlights statistically significant regions but also includes subthreshold locations, which provide key experimental context. This balances the dual needs of distilling modeling results and enabling informed interpretations for modern neuroimaging. We present four examples that demonstrate the many benefits of transparent thresholding, including: removing ambiguity, decreasing hypersensitivity to non-physiological features, catching potential artifacts, improving cross-study comparisons, reducing non-reproducibility biases, and clarifying interpretations. We also demonstrate the many software packages that implement transparent thresholding, several of which were added or streamlined recently as part of this work. A point-counterpoint discussion addresses issues with thresholding raised in real conversations with researchers in the field. We hope that by showing how transparent thresholding can drastically improve the interpretation (and reproducibility) of neuroimaging findings, more researchers will adopt this method.

Background/Objectives: Brain ischemia is a frequent complication in patients undergoing veno-arterial extracorporeal membrane oxygenation (va-ECMO) therapy due to hypoperfusion, low oxygenation, and thromboembolism. While concomitant intra-aortic balloon pump (IABP) therapy may improve the perfusion of the supra-aortic branches, it may also favor thromboembolism. This retrospective study aimed to evaluate the effects of combined va-ECMO and IABP therapy on procedural brain infarction compared to va-ECMO therapy alone, with a specific focus on analyzing the types of infarctions. Methods: Cranial computed tomography (CCT) scans of consecutive patients receiving va-ECMO therapy were analyzed retrospectively. Subgroups were formed for patients with combined therapy (ECMO and IABP) and va-ECMO therapy only. The types of infarctions and the potential impacts of va-ECMO vs. combined therapy with IABP on stroke were investigated. Results: Overall, 146 patients (36 female, 110 male, mean age 61 ± 13.3 years) were included, with 69 undergoing combined therapy and 77 patients receiving va-ECMO therapy alone. In total, 14 stroke events occurred in 11 patients in the ECMO-only group and there were 12 events in 12 patients in the ECMO + IABP-group, showing no significant difference (p = 0.61). The majority of infarctions were of thromboembolic (n = 23; 88%) origin, with 14 stroke-events in 12 patients in the ECMO + IABP-group and 9 stroke events in the ECMO-only group. The survival rate within 30 days of treatment was 29% in the ECMO-only group and 32% in the ECMO + IABP group. Conclusions: The results of this retrospective study show that concomitant IABP therapy appears to be neither protective nor more hazardous in relation to ECMO-related stroke. Thus, the indication for additional IABP therapy should be assessed independently from the procedural risk of brain ischemia. Thromboembolic infarctions seem to represent the most common type of infarction in ECMO, especially within the first 48 h of treatment.

Functional magnetic resonance imaging (fMRI) is a technique for indirectly measuring cerebral neural activity. It depends on the local cerebral vasculature and perfusion. It has thus been suggested that pathologies and normal variants of the cerebral vasculature can bias conclusions drawn from fMRI. The purpose of this study was to assess whether frequently observed asymmetries of the transverse sinuses are associated with apparent asymmetries of fMRI data timecourses. We re-analysed a publicly available resting state fMRI dataset (n = 135 healthy human subjects included in the main analysis). Voxel-mirrored homotopic connectivity (VMHC) was calculated as a measure of fMRI timecourse symmetry, reflecting the correlation of signal fluctuations in mirroring voxels in both cerebral hemispheres. Transverse sinus (TS) cross-sectional areas were measured in structural MRI data. In the main analysis, we assessed whether VMHC and TS asymmetry exhibited a negative linear association in brain areas near the transverse sinus. This was supplemented by exploratory whole brain analyses, including mapping of subthreshold effects. In the main hypothesis test, VMHC was not significantly associated with TS asymmetry in brain regions close to the transverse sinuses. In the whole brain analyses, VMHC was significantly negatively associated with TS asymmetry in more distant brain areas, and subthreshold effects resembled venous drainage patterns. The results suggest that part of the variance in resting state fMRI signal fluctuations might be explained by asymmetrical venous drainage. Thus, fMRI results might be confounded by the normal variability of the human intracranial venous system.

Stentretrievers are key devices for endovascular treatment of acute ischemic stroke. Aim of this post market clinical follow-up study was to asses safety and outcomes of interventions using the APERIO® Hybrid/Hybrid17|21 thrombectomy device (AHD) in routine clinical use. We conducted a prospectively monitored, multicenter, national registry study with single-arm data collection including patients with acute intracranial vessel occlusion (anterior and posterior circulation, including medium vessel occlusions) who were treated with the AHD in Germany between November 2020 and June 2023. Patients (n = 173) with low pre-stroke morbidity (modified Rankin Scale [mRS] ≤ 2) were included. We assessed technical recanalization success (mTICI ≥ 2b), the occurrence of periprocedural symptomatic intracranial hemorrhages (sICH), good clinical outcome (mRS ≤ 2 at 90 days), and secondary outcomes. Recanalization mTICI ≥ 2b was achieved in 84.4

It has been increasingly popular to acquire short tau inversion recovery (STIR) images in brachial plexus magnetic resonance imaging after injection of a gadolinium-based contrast medium in order to improve blood vessel suppression. This example highlights the potential pitfall that the signal of plexus lesions and anatomical structures such as the dorsal root ganglia can be suppressed in gadolinium-enhanced STIR compared with nonenhanced STIR images.

BACKGROUND: Spreading depolarization describes a near-complete electrical discharge with altered local cerebral blood flow. It is described in association with acute and chronic diseases like hemorrhagic stroke or migraine. Moyamoya vasculopathy is a chronic, progressive cerebrovascular disorder leading to cerebral hypoperfusion, hemodynamically insufficient basal collateralization, and increased cortical microvascularization. METHODS: In a prospective case series, we monitored for spontaneous spreading depolarization activity by using intraoperative laser speckle imaging for real-time visualization and measurement of cortical perfusion and cerebrovascular reserve capacity during cerebral revascularization in 4 consecutive patients with moyamoya. RESULTS: Spontaneous spreading depolarization occurrence was documented in a patient with moyamoya before bypass grafting. Interestingly, this patient also exhibited a marked preoperative increase in angiographic collateral vessel formation. CONCLUSIONS: The spontaneous occurrence of SDs in moyamoya vasculopathy could potentially provide an explanation for localized cortical infarction and increased cortical microvascular density in these patients.

Many functional magnetic resonance imaging (fMRI) studies rely on mass-univariate inference with subsequent multiple comparison correction. Statistical results are frequently visualized as thresholded statistical maps. This approach has inherent limitations including the risk of drawing overly-selective conclusions based only on selective results passing such thresholds. This article gives an overview of both established and newly emerging approaches to supplement such conventional analyses by incorporating information about subthreshold effects with the aim to improve interpretation of findings or leverage a wider array of information. Topics covered include neuroimaging data visualization, p-value histogram analysis and the related Higher Criticism approach for detecting rare and weak effects as well as multivariate analyses and dedicated Bayesian approaches.

Functional connectivity (FC) between and within a majority of cognition-related brain networks is altered in young adults with Fetal Alcohol Syndrome. Findings in a network-level analysis of resting-state fMRI data with a Higher Criticism approach were most obvious within a dorsal attention subnetwork and to a lesser extent in a salience / ventral attention subnetwork. When analyzing these effects further by looking at single connections, no individual FC alteration was statistically significant when adjusting for multiple comparisons. The finding of a wide distribution of FC alterations across networks might help resolve partially contradictory results in previous studies.

BackgroundGlycogen storage disease type 5 (McArdle disease) leads to a deficiency in the activity of myophosphorylase resulting in an impaired glucose utilization. The disease can be caused by a variety of mutations in the PYGM gene, and its typical clinical manifestation is muscles weakness within the first three decades of life.Case presentationIn this case report we present the diagnostic work-up of a physically active 78-year-old Caucasian patient suffering from a 2-year history of progressive camptocormia including clinical, radiologic, histological, and genetic tests. There was no history of neuro-muscular diseases in the family. Serum CK levels were moderately increased while other blood/urine parameters were normal. Magnetic resonance imaging showed fatty remodeling of the muscles of the back. Histochemical examination of a muscle biopsy revealed the absence of myophosphorylase activity, while gene analysis identified a known early-onset McArdle mutation in the PYGM gene.ConclusionThis case highlights that the clinical spectrum of PYGM gene mutation typically manifest during adolescence, but it is also a differential diagnosis in late onset muscle disorders and emphases the investigation of the role of ACE inhibitors in this disease.

Introduction:Aging influences the morphology of the central nervous system. While several previous studies focused on morphometric changes of the supratentorial parts, investigations on age-related cerebellar changes are rare. The literature concerning the morphological changes in the cerebellum is heterogenous depending (i) on the methods used (cerebellar analysis in the context of a whole brain analysis or specific methods for a cerebellar analysis), (ii) the life span that was investigated, and (iii) the analytic approach (i.e., using linear or non-linear methods). Methods:We fill this research gap by investigating age-dependent cerebellar changes in the aging process occurring before the age of 70 in healthy participants, using non-linear methods and the spatially unbiased infratentorial template (SUIT) toolbox which is specifically developed to examine the cerebellum. Furthermore, to derive an overview of the possible behavioral correlates, we relate our findings to functional maps of the cerebellum. Twenty-four older participants (mean age 64.42 years, SD ± 4.8) and 25 younger participants (mean age 24.6 years, SD ± 2.14) were scanned using a 3 T-MRI, and the resulting data were processed using a SUIT. Results:Gray matter (GM) volume loss was found in older participants in three clusters in the right cerebellar region, namely crus I/II and lobule VI related to the frontoparietal network, with crus I being functionally related to the default-mode network and lobule VI extending into vermis VIIa related to the ventral-attention-network. Discussion:Our results underline an age-related decline in GM volume in the right cerebellar regions that are functionally predominantly related to non-motor networks and cognitive tasks regions of the cerebellum before the age of 70.

Background: The occurrence of obstructive and central sleep apnea syndromes, ventilator pump failure and reduced hypercapnic ventilatory drive in myotonic dystrophy type 1 (DM1) is well established, and there are indications for an impairment of the hypoxic ventilator drive, too. Yet, it is still unknown, to which extent the respiratory rhythm is affected by DM1, thus if a central bradypnea, cluster breathing or ataxic (“Biot's”) breathing can occur. Additionally, the causes of the impairment of the central respiratory drive in DM1 are not known. Case Presentation: We present the case of a tracheotomized female patient with DM1 with central bradypnea and ataxic breathing. A 57-year-old woman with DM1 was admitted to our Neurointensive Care Unit (NICU) due to refractory tracheobronchial retention of secretions resulting from aspiration of saliva. Due to a combination of chronic hypercapnic respiratory failure, severe central bradypnea with a minimal breathing frequency of 3 per minute and ataxic breathing a pressure-controlled home ventilation was initiated. Conclusions: In our patient central bradypnea and ataxic breathing possibly were respiratory sequale of DM1, that may have been caused by pontine white matter lesions affecting the pontine respiratory nuclei. From a clinical viewpoint, polygraphy is a suitable tool to objectify disorders of the respiratory rhythm in DM1 even in tracheotomized patients. Clinical studies combining respiratory diagnostics as polygraphy, transcutaneous capnometry and blood gas analysis with brain magnetic resonance imaging (MRI) are required to better understand disorders of respiratory regulation in DM1, and to identify their anatomical correlates.

Background Fetal alcohol syndrome (FAS) can result in cognitive dysfunction. Cognitive functions affected are subserved by few functional brain networks. Functional connectivity (FC) in these networks can be assessed with resting-state functional MRI (rs-fMRI). Alterations of FC have been reported in children and adolescents prenatally exposed to alcohol. Previous reports varied substantially regarding the exact nature of findings. The purpose of this study was to assess FC of cognition-related networks in young adults with FAS. Methods Cross-sectional rs-fMRI study in participants with FAS ( n = 39, age: 20.9 ± 3.4 years) and healthy participants without prenatal alcohol exposure ( n = 44, age: 22.2 ± 3.4 years). FC was calculated as correlation between cortical regions in ten cognition-related sub-networks. Subsequent modelling of overall FC was based on linear models comparing FC between FAS and controls. Results were subjected to a hierarchical statistical testing approach, first determining whether there is any alteration of FC in FAS in the full cognitive connectome, subsequently resolving these findings to the level of either FC within each network or between networks based on the Higher Criticism (HC) approach for detecting rare and weak effects in high-dimensional data. Finally, group differences in single connections were assessed using conventional multiple-comparison correction. In an additional exploratory analysis, dynamic FC states were assessed. Results Comparing FAS participants with controls, we observed altered FC of cognition-related brain regions globally, within 7 out of 10 networks, and between networks employing the HC statistic. This was most obvious in attention-related network components. Findings also spanned across subcomponents of the fronto-parietal control and default mode networks. None of the single FC alterations within these networks yielded statistical significance in the conventional high-resolution analysis. The exploratory time-resolved FC analysis did not show significant group differences of dynamic FC states. Conclusions FC in cognition-related networks was altered in adults with FAS. Effects were widely distributed across networks, potentially reflecting the diversity of cognitive deficits in FAS. However, no altered single connections could be determined in the most detailed analysis level. Findings were pronounced in networks in line with attentional deficits previously reported.

Parkinson's disease (PD) can affect speech as well as emotion processing. We employ whole-brain graph-theoretical network analysis to determine how the speech-processing network (SPN) changes in PD, and assess its susceptibility to emotional distraction. Functional magnetic resonance images of 14 patients (aged 59.6 ± 10.1 years, 5 female) and 23 healthy controls (aged 64.1 ± 6.5 years, 12 female) were obtained during a picture-naming task. Pictures were supraliminally primed by face pictures showing either a neutral or an emotional expression. PD network metrics were significantly decreased (mean nodal degree, p < 0.0001; mean nodal strength, p < 0.0001; global network efficiency, p < 0.002; mean clustering coefficient, p < 0.0001), indicating an impairment of network integration and segregation. There was an absence of connector hubs in PD. Controls exhibited key network hubs located in the associative cortices, of which most were insusceptible to emotional distraction. The PD SPN had more key network hubs, which were more disorganized and shifted into auditory, sensory, and motor cortices after emotional distraction. The whole-brain SPN in PD undergoes changes that result in (a) decreased network integration and segregation, (b) a modularization of information flow within the network, and (c) the inclusion of primary and secondary cortical areas after emotional distraction.

Speech production relies on the interplay of different brain regions. Healthy aging leads to complex changes in speech processing and production. Here, we investigated how the whole-brain functional connectivity of healthy elderly individuals differs from that of young individuals. In total, 23 young (aged 24.6 ± 2.2 years) and 23 elderly (aged 64.1 ± 6.5 years) individuals performed a picture naming task during functional magnetic resonance imaging. We determined whole-brain functional connectivity matrices and used them to compute group averaged speech production networks. By including an emotionally neutral and an emotionally charged condition in the task, we characterized the speech production network during normal and emotionally challenged processing. Our data suggest that the speech production network of elderly healthy individuals is as efficient as that of young participants, but that it is more functionally segregated and more modularized. By determining key network regions, we showed that although complex network changes take place during healthy aging, the most important network regions remain stable. Furthermore, emotional distraction had a larger influence on the young group's network than on the elderly's. We demonstrated that, from the neural network perspective, elderly individuals have a higher capacity for emotion regulation based on their age-related network re-organization.

Despite potentially life-threatening symptoms of disordered breathing in severe cerebral illness, there are no clear recommendations on diagnostic and therapeutic strategies for these patients. To identify types of breathing disorders observed in severely neurological comprised patients, to direct further research on classification, pathophysiology, diagnosis and treatment for disordered breathing in cerebral disease. Data including polygraphy, transcutaneous capnometry, blood gas analysis and radiological examinations of patients with severe cerebral illness and disordered breathing admitted to the neurological intensive care were analyzed. Patients (15) presented with acquired central hypoventilation syndrome (ACHS), central bradypnea, central tachypnea, obstructive, mixed and central apneas and hypopneas, Cheyne Stokes respiration, ataxic (Biot's) breathing, cluster breathing and respiration alternans. Severe cerebral illness may result in an ACHS and in a variety of disorders of the respiratory rhythm. Two of these, abrupt switches between breathing patterns and respiration alternans, suggest the existence of a rhythmogenic respiratory network. Polygraphy, transcutaneous capnometry, blood gas analysis and MRI are promising tools for diagnosis and research alike.

Background Recently introduced MRI techniques facilitate accelerated examinations or increased resolution with the same duration. Further techniques offer homogeneous image quality in regions with anatomical transitions. The question arises whether and how these techniques can be adopted for routine diagnostic imaging. Methods Narrative review with an educational focus based on current literature research and practical experiences of different professions involved (physicians, MRI technologists/radiographers, physics/biomedical engineering). Different hardware manufacturers are considered. Results and Conclusions Compressed sensing and simultaneous multi-slice imaging are novel acceleration techniques with different yet complimentary applications. They do not suffer from classical signal-to-noise-ratio penalties. Combining 3 D and acceleration techniques facilitates new broader examination protocols, particularly for clinical brain imaging. In further regions of the nervous systems mainly specific applications appear to benefit from recent technological improvements. Key points: Citation Format

HomeStrokeVol. 53, No. 9Small Cerebral Infarcts Mimicked by Nuchal Lymph Nodes in Accelerated High-Resolution Diffusion Magnetic Resonance Imaging Free AccessCase ReportPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessCase ReportPDF/EPUBSmall Cerebral Infarcts Mimicked by Nuchal Lymph Nodes in Accelerated High-Resolution Diffusion Magnetic Resonance Imaging Benedikt Sundermann, Claudia Klüner, Holger Bösenberg, Maike Gerdes and Christian Mathys Benedikt SundermannBenedikt Sundermann Correspondence to: Benedikt Sundermann, MD, Evangelisches Krankenhaus Oldenburg, Steinweg 13-17, 29129 Oldenburg, Germany. Email E-mail Address: [email protected] https://orcid.org/0000-0003-4390-3464 Institute of Radiology and Neuroradiology, Evangelisches Krankenhaus Oldenburg, Medical Campus University of Oldenburg, Germany (B.S., C.K., H.B., M.G., C.M.). Research Center Neurosensory Science, University of Oldenburg, Germany (B.S., C.M.). , Claudia KlünerClaudia Klüner Institute of Radiology and Neuroradiology, Evangelisches Krankenhaus Oldenburg, Medical Campus University of Oldenburg, Germany (B.S., C.K., H.B., M.G., C.M.). , Holger BösenbergHolger Bösenberg Institute of Radiology and Neuroradiology, Evangelisches Krankenhaus Oldenburg, Medical Campus University of Oldenburg, Germany (B.S., C.K., H.B., M.G., C.M.). , Maike GerdesMaike Gerdes Institute of Radiology and Neuroradiology, Evangelisches Krankenhaus Oldenburg, Medical Campus University of Oldenburg, Germany (B.S., C.K., H.B., M.G., C.M.). and Christian MathysChristian Mathys https://orcid.org/0000-0002-5245-4958 Institute of Radiology and Neuroradiology, Evangelisches Krankenhaus Oldenburg, Medical Campus University of Oldenburg, Germany (B.S., C.K., H.B., M.G., C.M.). Research Center Neurosensory Science, University of Oldenburg, Germany (B.S., C.M.). Originally published13 Jul 2022https://doi.org/10.1161/STROKEAHA.122.039481Stroke. 2022;53:e420–e421Other version(s) of this articleYou are viewing the most recent version of this article. Previous versions: July 13, 2022: Ahead of Print Key PointIncomplete slice separation in simultaneous multislice diffusion-weighted magnetic resonance imaging can lead to leakage of signals from extracranial structures into the brain, which may strongly resemble ischemic lesions.Simultaneous multislice (SMS) techniques1 are increasingly used for accelerated diffusion-weighted imaging as part of routine magnetic resonance imaging protocols. SMS facilitates imaging of ≥2 slices at the same time. This can be used to accelerate imaging and obtain higher resolution images with potentially increased sensitivity for small infarcts.2,3 Signals from simultaneously excited slices are separated by techniques comparable to parallel imaging. Imperfect slice separation leads to (usually minor) signal contributions from distant slices, so-called slice leakage artifacts.1,4 In current SMS implementations, these artifacts are additionally shifted in phase-encoding direction.5The Figure shows an example of SMS-accelerated diffusion-weighted imaging. Focal hyperintensities strongly resembling small ischemic lesions could be attributed to small nuchal lymph nodes and thus to a typical slice leakage artifact. Knowledge of this artifact specific to SMS acceleration is therefore important to avoid false-positive stroke diagnosis.Download figureDownload PowerPointFigure. Simultaneous multislice (SMS)–accelerated diffusion-weighted imaging (DWI; 1.5 Tesla, slice thickness: 2.5 mm, SMS acceleration factor: 2, generalized autocalibrating partial parallel acquisition (GRAPPA) acceleration factor: 2, acquisition time: 2:03 min) in an asymptomatic patient. Images (A) and (B) represent consecutive DWI slices with focal hyperintensities (arrows) appearing in or near the cortex. However, they had ambiguous apparent diffusion coefficients and missing correlates in other sequences. An example is the missing finding in 3D fluid-attenuated inversion recovery (FLAIR; C) at the same level as (A). These apparent brain lesions strongly resemble the shape of lymph nodes (arrows) in far inferior DWI slices (D and E). The arrow in FLAIR (F) highlights the same lymph node as in (A) and (D). Thus the hyperintensities in (A) and (B) can be explained as a leakage of signals from strongly hyperintense lymph nodes into slices within the brain. They mimic DWI hyperintense focal infarcts.Article InformationSources of FundingNone.Disclosures Dr Mathys reports consulting and lecturing for Siemens on behalf of the employer (Evangelisches Krankenhaus Oldenburg), contract between the employer and Siemens. The other authors report no conflicts.FootnotesFor Sources of Funding and Disclosures, see page e421.Correspondence to: Benedikt Sundermann, MD, Evangelisches Krankenhaus Oldenburg, Steinweg 13-17, 29129 Oldenburg, Germany. Email benedikt.sundermann@uni-muenster.deReferences1. Barth M, Breuer F, Koopmans PJ, Norris DG, Poser BA. Simultaneous Multislice (SMS) imaging techniques.Magn Reson Med. 2016; 75:63–81. doi: 10.1002/mrm.25897Google Scholar2. Runge VM, Richter JK, Heverhagen JT. Speed in clinical magnetic resonance.Invest Radiol. 2017; 52:1–17. doi: 10.1097/RLI.0000000000000330Google Scholar3. Sundermann B, Billebaut B, Bauer J, Iacoban C, Alykova O, Schülke C, Gerdes M, Kugel H, Neduvakkattu S, Bösenberg H, et al. Practical aspects of novel MRI techniques in neuroradiology: Part 2 – acceleration methods and implications for individual regions [published online May 11, 2022].Rofo. 2022. doi: 10.1055/a-1800-8789Google Scholar4. McNabb CB, Lindner M, Shen S, Burgess LG, Murayama K, Johnstone T. Inter-slice leakage and intra-slice aliasing in simultaneous multi-slice echo-planar images.Brain Struct Funct. 2020; 225:1153–1158. doi: 10.1007/s00429-020-02053-2Google Scholar5. Todd N, Moeller S, Auerbach EJ, Yacoub E, Flandin G, Weiskopf N. Evaluation of 2D multiband EPI imaging for high-resolution, whole-brain, task-based fMRI studies at 3T: Sensitivity and slice leakage artifacts.Neuroimage. 2016; 124(Pt A):32–42. doi: 10.1016/j.neuroimage.2015.08.056Google Scholar eLetters(0)eLetters should relate to an article recently published in the journal and are not a forum for providing unpublished data. Comments are reviewed for appropriate use of tone and language. Comments are not peer-reviewed. Acceptable comments are posted to the journal website only. Comments are not published in an issue and are not indexed in PubMed. Comments should be no longer than 500 words and will only be posted online. References are limited to 10. Authors of the article cited in the comment will be invited to reply, as appropriate.Comments and feedback on AHA/ASA Scientific Statements and Guidelines should be directed to the AHA/ASA Manuscript Oversight Committee via its Correspondence page.Sign In to Submit a Response to This Article Previous Back to top Next FiguresReferencesRelatedDetails September 2022Vol 53, Issue 9 Advertisement Article InformationMetrics © 2022 American Heart Association, Inc.https://doi.org/10.1161/STROKEAHA.122.039481PMID: 35862210 Originally publishedJuly 13, 2022 Keywordsartifactsbraininfactionlymph nodesmagnetic resonance imagingPDF download Advertisement SubjectsMagnetic Resonance Imaging (MRI)