Christian H Riedel

• MD
• Medical Doctor at Universitätsmedizin Göttingen

While MRI has become the imaging modality of choice for intracranial meningiomas, no radiologic reporting guidance exists to date that relies on a systematic collection of information relevant to the core medical disciplines involved in the management of these patients. To address this issue, a nationwide expert survey was conducted in Germany. A l...

Introduction The impact of streamlining algorithms for stroke patients on process times in pre-hospital emergency medicine (PHEM) is not well investigated. We analyzed the changes in pre- and in-hospital process times after implementation of a streamlining algorithm in a physician staffed PHEM system. Patients We conducted a prospective observatio...

Introduction Cerebral vasospasm (CV) is a devastating medical complication of aneurysmal subarachnoid hemorrhage (SAH). The current endovascular approach includes intra-arterial vasodilators and angioplasty. Aim of Study We present interim data from a multi-center study evaluating the safety and effectiveness of angioplasty with the Comaneci devic...

Background and purpose The new p64 flow diverter with hydrophilic polymer coating (HPC) was designed to reduce thrombogenicity. To date, it is unclear how antithrombogenic surface modifications affect neoendothelialization and thrombus formation in patients with unruptured intracranial aneurysms. The purpose of this study was to evaluate the safety...

Purpose While MRI has become the imaging modality of choice in the diagnosis of sellar tumors, no systematic attempthas yet been made to align radiological reporting of findings with the information needed by the various medical disciplinesdealing with these patients. Therefore, we aimed to determine the prevailing preferences in this regard throug...

Background: While MRI has become the imaging modality of choice for intracranial meningiomas, no radiologic reporting guidance exists to date that relies on a systematic collection of information relevant to the core medical disciplines involved in the management of these pa- tients. To address this issue, a nationwide expert survey was conducted i...

Introduction Subarachnoid haemorrhage (SAH) can result in cerebral vasospasms and delayed cerebral ischemia, which contribute significantly to morbidity and mortality. The effectiveness of endovascular treatment for this condition is still a subject of debate. However, the adjustable neck-bridging device Comaneci (Rapid Medical, Yokneam, Israel) ma...

Background Predicting a challenging clot when performing mechanical thrombectomy in acute stroke can be difficult. One reason for this difficulty is a lack of agreement on how to precisely define these clots. We explored the opinions of stroke thrombectomy and clot research experts regarding challenging clots, defined as difficult to recanalize clo...

Objective Presurgical high‐density electric source imaging (hdESI) of interictal epileptic discharges (IEDs) is only used by few epilepsy centers. One obstacle is the time‐consuming workflow both for recording as well as for visual review. Therefore, we analyzed the effect of (a) an automated IED detection and (b) the number of IEDs on the accuracy...

Background Although Dementia with Lewy bodies (DLB) is the second most common form of dementia in elderly patients, it remains underdiagnosed compared with Alzheimer's (AD) and Parkinson's diseases (PD). This may be explained by overlapping clinical symptoms, e.g. Parkinsonism. While current MRI research focuses primarily on atrophy patterns of the...

Purpose Our article is dedicated to describing the state-of-the-art in imaging techniques for assessing prodromal dementia with Lewy bodies (pro-DLB) with a psychiatric-onset. Materials and methods Imaging biomarker techniques are discussed. Results (123)-I-2-ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl) nortropane single photon emission co...

Purpose Diffusion-weighted imaging (DWI) is important for differentiating residual tumor and subacute infarctions in early postoperative magnetic resonance imaging (MRI) of central nervous system (CNS) tumors. In cases of pneumocephalus and especially in the presence of intraventricular trapped air, conventional echo-planar imaging (EPI) DWI is dis...

Background: Prodromal dementia with Lewy bodies (DLB) can emerge with the onset of mild cognitive impairment (MCI). Standard biomarkers can help identify such patients to improve therapy and treatment strategies. Our review aims to describe the latest evidence on promising biomarkers in prodromal DLB with MCI onset (MCI-LB). Methods: We selected...

Background Dementia with Lewy bodies (DLB) is a type of dementia often diagnosed in older patients. Since its initial symptoms range from delirium to psychiatric and cognitive symptoms, the diagnosis is often delayed. Objectives In our study, we evaluated the magnetic resonance imaging (MRI) of patients suffering from DLB in correlation with their...

Zusammenfassung Hintergrund und Ziel Eine strukturierte MRT-Befundung unter Verwendung konsensbasierter inhaltlicher Kategorien hat das Potenzial, die interdisziplinäre Kommunikation in der Neuroonkologie zu verbessern. Ziel dieser Studie war es daher, mittels einer bundesweiten Befragung von Mitgliedern medizinischer Fachgesellschaften mit neuroo...

Background: The aim of this study was to evaluate the reproducibility and clinical value of the novel single-shot T1 mapping method for rapid and accurate multi-slice coverage of the whole brain, described by Wang et al. 2015. Methods: At a field strength of 3 Tesla, T1 mappings of 139 patients (51 of them without pathologic findings) and two re...

Persistent stuttering is a prevalent neurodevelopmental speech disorder, which presents with involuntary speech blocks, sound and syllable repetitions, and sound prolongations. Affected individuals often struggle with negative feelings, elevated anxiety, and low self-esteem. Neuroimaging studies frequently link persistent stuttering with cortical a...

Background The implementation of a collective terminology in radiological reporting such as the RSNA radiological lexicon (RadLex) yields many benefits including unambiguous communication of findings, improved education, and fostering data mining for research purposes. While some fields in general radiology have already been evaluated so far, this...

Abstract Background Dementia with Lewy bodies (DLB) is the second most common dementia type in patients older than 65 years. Its atrophy patterns remain unknown. Its similarities to Parkinson's disease and differences from Alzheimer's disease are subjects of current research. Methods The aim of our study was (i) to form a group of patients with DLB...

Background Decision-making about the indication for decompressive hemicraniectomy in cases with malignant infarction in the territory of the middle cerebral artery (MCA) is still a matter of debate. Some scores have been introduced and tested, most of them are midline-shift dependent. We introduce the Kinematics of malignant MCA infarction (KM) ind...

Objective Traumatic brain injury (TBI) constitutes a major cause of trauma-related disability and mortality. The epidemiology and implications of associated cranial nerve injuries (CNI) in moderate to severe TBI are largely unknown. We aimed to determine the incidence of CNI in a large European cohort of TBI patients as well as clinical differences...

Purpose The implementation of a collective terminology in radiological reporting such as the RSNA radiological lexicon (RadLex) yields many benefits including unambiguous communication of findings, improved education, and fostering data mining for research purposes. While some fields in general radiology have already been evaluated so far, this is...

Background Traumatic brain injury (TBI) constitutes a major cause of trauma-related disability and mortality. The epidemiology and implications of associated cranial nerve injuries (CNI) in moderate to severe TBI are largely unknown. We aimed to determine the prevalence of CNI in a large European cohort of TBI patients as well as clinical differenc...

Studies show that psychiatric symptoms in adults and children are sometimes associated with serum neural autoantibodies. The significance of serum neural autoantibodies associated with psychiatric symptoms in children remains often unclear, but might be relevant for the extent and occurrence of psychiatric disease manifestation in later life, as we...

Frailty is associated with an increased risk of adverse health-care outcomes in elderly patients. The Hospital Frailty Risk Score (HFRS) has been developed and proven to be capable of identifying patients which are at high risk of adverse outcomes. We aimed to investigate whether frail patients also face adverse outcomes after experiencing an endov...

Background: Brain metastases are particularly common in patients with small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), with NSCLC showing a less aggressive clinical course and lower chemo- and radio sensitivity compared to SCLC. Early adequate therapy is highly desirable and depends on a reliable classification of tumor type....

Introduction Diffusion-weighted imaging in stimulated echo acquisition mode (STEAM-DWI) is an interesting alternative with less susceptibility artifacts compared to the most commonly used diffusion-weighted echo-planar imaging (EPI-DWI). Sensitivity and specificity of a novel STEAM-DWI, described by Merrem et al. 2017 [1], were assessed in patients...

Background and purpose: In certain clinical circumstances, dual-antiplatelet therapy can be problematic in patients with acute SAH. In some aneurysms, however, flow-diverting stents are the ideal therapeutic option. We report our experience with ruptured intracranial aneurysms treated with flow diverters with hydrophilic coating (p48 MW HPC and p6...

Recent studies have identified two distinct cortical representations of voice control in humans, the ventral and the dorsal laryngeal motor cortex. Strikingly, while persistent developmental stuttering has been linked to a white matter deficit in the ventral laryngeal motor cortex, intensive fluency shaping intervention modulated the functional con...

Background: Brain metastases are particularly common in patients with small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), with NSCLC showing a more aggressive clinical course and lower chemo- and radio sensitivity compared to SCLC. Early adequate therapy is highly desirable and depends on a reliable classification of tumor type. T...

Background Autoimmune-mediated encephalitis is a disease that often encompasses psychiatric symptoms as its first clinical manifestation’s predominant and isolated characteristic. Novel guidelines even distinguish autoimmune psychosis from autoimmune encephalitis. The aim of this review is thus to explore whether a wide range of psychiatric symptom...

Recent studies have identified two distinct cortical representations of voice control in humans, the ventral and the dorsal laryngeal motor cortex. Strikingly, while persistent developmental stuttering has been linked to a white matter deficit in the ventral laryngeal motor cortex, intensive fluency shaping intervention modulated the functional con...

This prospective observational study focuses on developmental outcomes in the treatment of tuberous sclerosis complex (TSC) with everolimus (EVO). Fourteen children/adolescents aged 1.7–13.07 and one adult aged 31 years, all with TSC and refractory epilepsy participated. All were treatedwith EVO for 3–70months (md: 37). Development/adaptive functio...

Objectives The aim was to measure the effective dose of flat-detector CT (FDCT) whole-brain imaging, biphasic FDCT angiography (FDCT-A), and FDCT perfusion (FDCT-P) protocols and compare it to previously reported effective dose values of multidetector CT (MDCT) applications.MaterialsWe measured effective dose according to the IRCP 103 using an anth...

Background Mechanical thrombectomy has become the standard care for acute ischemic stroke caused by large vessel occlusion. However, complete reperfusion cannot be achieved in all cases, and several factors influencing the results of mechanical thrombectomy have been investigated. Among others, a tortuous anatomy is associated with lower rates of c...

Cerebral Autosomal Recessive Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CARASIL, Maeda syndrome) is an extremely rare autosomal-recessive genetic disorder with a serious arteriopathy causing subcortical infarcts and leukoencephalopathy. In less than 20 cases, a genetic mutation was proven. Patients suffer from alopecia, disc he...

Background: Motor and cognitive deficits and consequently mobility problems are common in geriatric patients. The currently available methods for diagnosis and for the evaluation of treatment in this vulnerable cohort are limited. The aims of the ComOn (COgnitive and Motor interactions in the Older populatioN) study are (i) to define quantitative...

Light-responsive contrast agents for magnetic resonance imaging (MRI) based on Ni(II)porphyrin molecular spin switches have been recently introduced. We present their implementation in water and methanol based gels leading to...

Background: Efficient personalized therapy paradigms are needed to modify the disease course and halt gray (GM) and white matter (WM) damage in patients with multiple sclerosis (MS). Presently, promising disease-modifying drugs show impressive efficiency, however, tailored markers of therapy responses are required. Here, we aimed to detect in a rea...

Background: Deep brain stimulation (DBS) is an effective evidence-based therapy for dystonia. However, no unequivocal predictors of therapy responses exist. We investigate whether patients optimally responding to DBS present distinct brain network organization and structural patterns. Methods: Eighty-two dystonia patients with segmental and general...

Aim The purpose of our study was to compare the agreement of both the total Alberta Stroke Program Early CT Score (ASPECTS) and region-based scores from two automated ASPECTS software packages and an expert consensus (EC) reading with final ASPECTS in a selected cohort of patients who had prompt reperfusion from endovascular thrombectomy (EVT). Me...

JC‐virus (JCV) infection of the central nervous system (CNS) causes progressive multifocal leukoencephalopathy (PML) in patients with systemic immunosuppression. With the increased application of modern immunotherapy and biologics in various immune‐mediated disorders, the PML risk spectrum has changed. Thus, new tools and strategies for risk assess...

Background and purpose: The goal of the analysis of revascularisation in ischaemic stroke with EmboTrap study (ARISE I) was to demonstrate the effectiveness of EmboTrap. Methods: ARISE I was an open label, single arm, multicentre, prospective study for the treatment of acute stroke due to large vessel occlusion. The primary outcome was revascula...

Background: Deep brain stimulation (DBS) is an effective evidence-based therapy for dystonia. However, no unequivocal predictors of therapy responses exist. We investigate whether patients optimally responding to DBS present distinct brain network organization and structural patterns. Methods: Based on a German multicentre cohort of eighty-two dyst...

Background: CT perfusion (CTP) and diffusion or perfusion MRI might assist patient selection for endovascular thrombectomy. We aimed to establish whether imaging assessments of irreversibly injured ischaemic core and potentially salvageable penumbra volumes were associated with functional outcome and whether they interacted with the treatment effe...

Background:

Background and purpose: Recent studies have suggested that wall enhancement of unruptured intracranial aneurysms in high-resolution MR imaging might serve as an imaging biomarker for higher risk of rupture. Histologic studies have revealed a possible association among inflammatory processes, degeneration, and destabilization of the aneurysm wall p...

Background: The stent retriever assisted vacuum-locked extraction (SAVE) technique was introduced as an effective thrombectomy method in stroke patients suffering from intracranial large vessel occlusion (LVO). This article presents our multicenter, large-scale experience with SAVE. Methods: The study involved a retrospective core team analysis...

Background The Stent Retriever Assisted Vacuum-locked Extraction (SAVE) technique has been introduced as an effective embolectomy method in stroke patients suffering from intracranial large vessel occlusion (LVO). We present our multicenter, long-term experience with SAVE. Methods Retrospective, core-team analysis of 200 patients undergoing embole...

Background and purpose: EmboTrap is a novel stent retriever designed to achieve rapid and substantial flow restoration in acute ischemic stroke secondary to large-vessel occlusions. Here, we evaluated EmboTrap's safety and efficacy compared with established stent retrievers. Methods: ARISE II (Analysis of Revascularization in Ischemic Stroke Wit...

Background and purpose: Idiopathic intracranial hypertension is a syndrome of raised intracranial pressure of unknown etiology. Few MR imaging-based studies have investigated arterial and venous blood flow in these patients. Results are inconclusive, and to our knowledge, no comparison of the hemodynamic parameters before and after CSF pressure re...

Purpose Invasive aspergillosis usually affects immunocompromised patients. It carries a high risk of morbidity and mortality and usually has a nonspecific clinical presentation. Early diagnosis is essential in order to start effective treatment and improve clinical outcome. Materials and Methods In a retrospective search of the PACS databases from...

Obesity is associated with hypothalamic inflammation (HI) in animal models. In the present study we examined the mediobasal hypothalamus (MBH) of 57 obese human subjects and 54 age- and sex- matched non-obese controls by MRI and analyzed the T2-hyperintensity as a measure of HI. Obese subjects exhibited T2-hyperintensity in the left but not the rig...

While deep brain stimulation of the subthalamic nucleus (STN-DBS) has evolved to an evidence-based standard treatment for Parkinson’s disease (PD), the targeted cerebral networks are poorly described and no objective predictors for the postoperative clinical response exist. To elucidate the systemic mechanisms of DBS, we analysed cerebral grey matt...

Background and purpose As previously demonstrated, the recanalization rate and clinical outcome in patients with anterior circulation stroke treated with IV thrombolysis (IVT) depend on clot characteristics such as thrombus length and thrombus density. In patients with basilar artery occlusion (BAO) treated with IVT, the recanalization rate has als...

Background and purpose: Computed tomographic perfusion represents an interesting physiological imaging modality to select patients for reperfusion therapy in acute ischemic stroke. The purpose of our study was to determine the accuracy of different commercial perfusion CT software packages (Philips (A), Siemens (B), and RAPID (C)) to predict the f...

Introduction: Obesity is associated with hypothalamic inflammation (HI) in animal models. While MRI studies in humans also found an increased intensity in the MBH in obese subjects, it remains unclear (1) if HI causes neuronal death and (2) if HI reverses during weight loss. Patients and methods: n=50 obese subjects and n=50 age- and sex-matched co...

Introduction: Obesity is associated with hypothalamic inflammation (HI) in animal models. While MRI studies in humans also found an increased intensity in the MBH in obese subjects it remains unclear (1) if HI causes neuronal death and (2) if HI reverses during weight loss. Patients and methods: n = 50 obese subjects and n = 50 age- and sex-matched...

We present a fully reversible and highly efficient on-off photo switching of magnetic resonance imaging (MRI) contrast with green (500 nm) and violet-blue (435 nm) light. The contrast change is based on the intramolecular Light-Driven Coordination-Induced Spin State Switch (LD-CISSS) which was performed with azopyridine substituted Ni-porphyrins. T...

Purpose: The efficacy of i. v. thrombolysis in acute stroke with high clot burden is limited. Successful recanalization is very unlikely if the thrombus length exceeds 7 mm. Thus this retrospective controlled study evaluated the efficacy and safety of neurothrombectomy in the treatment of acute embolic stroke in patients selected by a thrombus leng...

Background: Platelet-leukocyte aggregation (PLA) and platelet activation are found to be on the higher side in ischemic stroke patients. The correlation of PLA with clinical features has not been intensively investigated and the influence of genetic factors on PLA is still unexplored. The interaction of platelets with leukocytes is mainly determin...

Introduction: Stent retriever procedures for clot removal in proximal cerebral arteries are often assumed to securely encase a clot for withdrawal. Hypothesis: We assessed the hypothesis that the interaction of a stent retriever device with a clot in proximal cerebral arteries typically leads to an encasement of the clot after a steady state of clo...

Mechanical hyperalgesia is one distressing symptom of neuropathic pain which is explained by central sensitization of the nociceptive system. This sensitization can be induced experimentally with the heat/capsaicin sensitization model. The aim was to investigate and compare spinal and supraspinal activation patterns of identical mechanical stimulat...

Background A multidisciplinary approach is recommended for patients with chronic deep vein thrombosis. Disease management has up to now been dominated by conservative treatment whereby anticoagulation therapy and in a few instances thrombolysis have major priority but thrombectomy is only rarely performed. However, these types of treatment often on...

Zielsetzung: Vergleich der Effizienz verschiedener Stent-Retriever in einem Flussmodell, welches einen akuten thrombembolischen Verschluss der ACM simuliert. Material und Methodik: Die Versuche wurden in einem hauseigenen Flussmodell, welches einen thrombembolischen ACM-Verschluss in einer geraden und einer gebogenen Gefassanatomie simuliert, mit v...

PurposeTo assess and characterize responses to innocuous/noxious thermal stimuli and heat allodynia using functional spinal magnetic resonance imaging (spinal fMRI).Materials and Methods Spinal/supraspinal activation patterns of 16 healthy subjects were investigated by applying painful and nonpainful heat stimuli to dermatome C6 baseline and after...

Postural tremor is the leading symptom in essential tremor, but in some cases intention tremor and limb ataxia emerge and can become highly disabling features. Deep brain stimulation of the thalamus or subthalamic white matter improve tremor and ataxia; however, the underlying network mechanisms are enigmatic. To elucidate the mechanisms of deep br...

To evaluate how accurately final infarct volume in acute ischemic stroke can be predicted with perfusion CT (PCT) using a 64-MDCT unit and the toggling table technique. Retrospective analysis of 89 patients with acute ischemic stroke who underwent CCT, CT angiography (CTA) and PCT using the “toggling table” technique within the first three hours af...

The Stroke Imaging Research (STIR) Group, the American Society of Neuroradiology, and the Foundation of the American Society of Neuroradiology sponsored a series of working group meetings >12 months, with the final meeting occurring during the Stroke Treatment Academy Industry Roundtable (STAIR) on March 9 to 10, 2013, in Washington, DC. This proce...

Using modern multi-detector CT scanners for imaging patients suffering from acute stroke not only allows for quantitative evaluation of diminished cerebral blood flow and blood volume in most parts of the supratentorial brain by CT perfusion imaging. It also offers valuable information on clot burden if simple thin-slice reconstructions are used to...

Zusammenfassung Moderne Multidetektor-Computertomografie in der Diagnostik des akuten Schlaganfalls erlaubt nicht nur die quantitative Bestimmung des zerebralen Blutvolumens und Blutflusses im nahezu gesamten supratentoriellen Hirngewebe durch CT-Perfusionsmessungen, sondern ermöglicht zusätzlich durch einfache dünnschichtige Rekonstruktionen der n...

The purpose of this study was to investigate whether thin-slice image reconstructions of cranial nonenhanced CT scans could be used to significantly increase sensitivity for detecting intraluminal thrombus in patients with acute ischemic stroke due to proximal occlusion of the middle cerebral artery. In a prospective case series, the raw data of no...

Background and purpose Recent studies have demonstrated that in acute ischemic stroke patients, thin section non-contrast CT (NCCT) can be used to determine the length of the hyperdense intracranial thrombus, and that clot length using this approach predicts the likelihood of vessel recanalization after intravenous tissue plasminogen activator. Sum...

Objective: While deep brain stimulation (DBS) of the subthalamic nucleus (STN) significantly improved the therapeutic options in Parkinson's disease, the direct mechanisms of DBS are poorly understood. To elucidate the systemic mechanisms of DBS, we pursued a multidisciplinary approach using preoperative high resolution DTI imaging and postoperativ...

Photosensitivity or photoparoxysmal response (PPR) is an electroencephalography trait that is highly associated with idiopathic generalized epilepsies (IGEs) and characterized by changes in cortical excitability in response to photic stimulation. Studying functional and structural changes of PPR might provide important insights into the pathogenesi...

We have read the recent article entitled “Quantification of Thrombus Hounsfield Units on Noncontrast CT Predicts Stroke Subtype and Early Recanalization after Intravenous Recombinant Tissue Plasminogen Activator” by Puig et al with great interest.[1][1] We congratulate the authors on their

Three-dimensional (3D) angiography is increasingly used in the diagnostics of brain aneurysms. Aim of the present study was to evaluate the accuracy of 3D angiograms with respect to its value for preoperative planning of aneurysm clipping. The 3D angiograms of 42 patients with subarachnoid bleeding caused by aneurysm rupture of the anterior circle...

Hirnperfusionsmessungen mit dem Computertomografen (CTP) erlauben die quantitative Bestimmung des zerebralen Blutflusses (CBF) und Blutvolumens (CBV). Bis vor Kurzem beschränkten sich solche Messungen auf ein kleines Scanfeld nahe der Schädelbasis. Durch die Einführung von Multidetektor-CT mit 64 und mehr Detektorzeilen ist es heute möglich, eine G...