Ulrike Ernemann

Universitätsklinikum Tübingen, Tübingen, Baden-Württemberg, Germany

Are you Ulrike Ernemann?

Claim your profile

Publications (274)612.61 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE The authors' aim in this paper is to prove the feasibility of resting-state (RS) functional MRI (fMRI) in an intraoperative setting (iRS-fMRI) and to correlate findings with the clinical condition of patients pre- and postoperatively. METHODS Twelve patients underwent intraoperative MRI-guided resection of lesions in or directly adjacent to the central region and/or pyramidal tract. Intraoperative RS (iRS)-fMRI was performed pre- and intraoperatively and was correlated with patients' postoperative clinical condition, as well as with intraoperative monitoring results. Independent component analysis (ICA) was used to postprocess the RS-fMRI data concerning the sensorimotor networks, and the mean z-scores were statistically analyzed. RESULTS iRS-fMRI in anesthetized patients proved to be feasible and analysis revealed no significant differences in preoperative z-scores between the sensorimotor areas ipsi- and contralateral to the tumor. A significant decrease in z-score (p < 0.01) was seen in patients with new neurological deficits postoperatively. The intraoperative z-score in the hemisphere ipsilateral to the tumor had a significant negative correlation with the degree of paresis immediately after the operation (r = -0.67, p < 0.001) and on the day of discharge from the hospital (r = -0.65, p < 0.001). Receiver operating characteristic curve analysis demonstrated moderate prognostic value of the intraoperative z-score (area under the curve 0.84) for the paresis score at patient discharge. CONCLUSIONS The use of iRS-fMRI with ICA-based postprocessing and functional activity mapping is feasible and the results may correlate with clinical parameters, demonstrating a significant negative correlation between the intensity of the iRS-fMRI signal and the postoperative neurological changes.
    No preview · Article · Jan 2016 · Journal of Neurosurgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Secondary vasospasm and disturbances in cerebrovascular autoregulation are associated with the development of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (SAH). An intra-arterial application of nimodipine has been shown to increase the vessel diameter, although this effect is transient. The feasibility of long-term, continuous, intra-arterial nimodipine (CIN) treatment and its effects on macrovasospasm, autoregulation parameters and outcome were evaluated in patients with refractory severe macrovasospasm. Methods: Ten patients were included with refractory macrovasospasm despite bolus nimodipine application (n=4) or with primary severe vasospasm (n=6). The patients were assessed with continuous multimodal neuromonitoring (MAP, ICP, CPP, pbrO2), daily TCD exams and CT-angiography/perfusion (CTA, CTP). Autoregulation indices, the pressure reactivity index (PRx) and oxygen reactivity index (ORx) were calculated. Indwelling microcatheters were placed in the extracranial internal carotid arteries and 0.4 mg nimodipine was continuously infused at 50 ml/hour. Results: The duration of CIN treatment ranged from 9-15 days. During treatment ICP remained stable, TCD flow velocity decreased and pbrO2 improved by 37%. Macrovasospasm, as assessed via CTA, had improved (n=5) or disappeared (n=5) at the end of treatment. Cerebrovascular autoregulation according to the PRx and ORx significantly worsened during treatment. All patients showed a favorable outcome (median GOS 5) at 3 months. Conclusions: In well-selected patients with prolonged severe macrovasospasm, continuous intra-arterial nimodipine treatment can be applied as a rescue therapy with relative safety for more than 2 weeks to prevent secondary cerebral ischemia. The induced impairment of cerebrovascular autoregulation during treatment seems to have no negative effects.
    No preview · Article · Dec 2015 · World Neurosurgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Second mitochondrial activator of caspase (Smac) is a short mitochondrial peptide. When released from the mitochondria into the cytoplasm, it binds to inhibitor of apoptotic proteins (IAPs) within the cytoplasm and prevents them from inhibiting apoptosis. Objective: Delivery of external synthetic Smac peptide into the cytoplasm of malignant cells could greatly improve the efficiency of apoptosis-inducing chemotherapeutic agents. Method: In our study different conjugates based on the seven N-terminal amino acids AVPIAQK of Smac (SmacN7) were produced to obtain a cytoplasm-directed Smac variant. SmacN7 and a point mutant (AVPKAQK) were coupled either to rhodamine alone or to both rhodamine and undecylic aldehyde, which is an antagonist of the Lily-of-the-valley fragrance receptor. The fifth conjugate consisted of rhodamine coupled only to undecylic aldehyde, without SmacN7. The uptake of these five conjugates into three different human cell lines was characterized and quantified by confocal laser scanning microscopy and flow cytometry. A caspase apoptosis assay was performed for cells incubated with the five different conjugates after induction of apoptosis. Results: The coupling of undecylic aldehyde to SmacN7 increased the cellular uptake of the correct and mutant conjugates. Conclusion: Caspase 3/7 apoptosis tests after induction of apoptosis with staurosporine or UV irradiation showed that the coupling of SmacN7 with undecylic aldehyde resulted in a greatly increased adjuvant pro-apoptotic effect compared to the separate components and a mutant SmacN7 peptide sequence in the LNCaP prostate carcinoma cells compared to the benign prostate hyperplasia (BPH) cells and the human embryonal kidney (HEK) cells.
    No preview · Article · Nov 2015 · Medicinal chemistry (Shāriqah (United Arab Emirates))
  • [Show abstract] [Hide abstract]
    ABSTRACT: Rationale and objectives: Resting-state (RS) networks, revealed by functional magnetic resonance imaging (fMRI) studies in healthy volunteers, have never been evaluated in anesthetized patients with brain tumors. Our purpose was to examine the presence of residual brain activity on the auditory network during propofol-induced loss of consciousness in patients with brain tumors. Materials and methods: Twenty subjects with intracranial masses were prospectively studied by means of intraoperative RS-fMRI acquisitions before any craniectomy. After performing single-subject independent component analysis, spatial maps and time courses were assigned to an auditory RS network template from the literature and compared via spatial regression coefficients. Results: All fMRI data were of sufficient quality for further postprocessing. In all but two patients, the RS functional activity of the auditory network could be successfully mapped. In almost all patients, contralateral activation of the auditory network was present. No significant difference was found between the mean distance of the RS activity clusters and the lesion periphery for tumors located in the temporal gyri vs. those in other brain regions. The spatial deviation between the activated cluster in our experiment and the template was significantly (P = 0.04) higher in patients with tumors located in the temporal gyri than in patients with tumors located in other regions. Conclusions: Propofol-induced anesthesia in patients with intracranial lesions does not alter the blood-oxygenation level-depended signal, and independent component analysis of intraoperative RS-fMRI may allow assessment of the auditory network in a clinical setting.
    No preview · Article · Nov 2015 · Academic radiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The present study aimed to analyse potential prognostic factors, with emphasis on tumour volume, in determining progression free survival (PFS) for malignancies of the nasal cavity and the paranasal sinuses. Retrospective analysis of 106 patients with primary sinonasal malignancies treated and followed-up between March 2006 and October 2012. Possible predictive parameters for PFS were entered into univariate and multivariate Cox regression analysis. Kaplan-Meier curve analysis included age, sex, baseline tumour volume (based on MR imaging), histology type, TNM stage and prognostic groups according to the American Joint Committee on Cancer (AJCC) classification. Receiver operating characteristic (ROC) curve analysis concerning the predictive value of tumour volume for recurrence was also conducted. The main histological subgroup consisted of epithelial tumours (77%). The majority of the patients (68%) showed advanced tumour burden (AJCC stage III-IV). Lymph node involvement was present in 18 cases. The mean tumour volume was 26.6 ± 21.2 cm Radiological tumour volume proofed to be a statistically reliable predictor of PFS. In the multivariate analysis, T-, N- and overall AJCC staging did not show significant prognostic value.
    Full-text · Article · Sep 2015 · Radiology and Oncology
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND Venous malformations of the limbs are congenital low-flow vascular anomalies. A treatment is reasonable if they are symptomatic or if a progressive lesion may affect functional structures.OBJECTIVE The purpose of this work is the presentation of clinical results after treatment of venous malformations of the limbs according to the standard algorithm used at the University Hospital of Tuebingen, Germany.PATIENTS AND METHODS Between January 2008 and June 2015, patients with venous malformations of the limbs were subjected to either percutaneous sclerotherapy or surgical excision according to this treatment algorithm. Remaining symptoms such as pain level and disturbing appearance before and after treatment as well as overall satisfaction was assessed the earliest 3 months after last treatment.RESULTSThirty-nine patients with venous malformations of the limbs were subjected to either 1 or more percutaneous sclerotherapies (n = 19) or surgical excision (n = 21). There were no serious complications that needed surgical revision. There was a statistically significant reduction in the pain level and disturbing appearance after both sclerotherapy and surgical excision (p < .05) in 30 cases in total. The overall treatment satisfaction was rated 7.9/10 and 8.8/10 after sclerotherapy and surgical excision, respectively.CONCLUSIONA low complication rate with a high patient satisfaction could be achieved after this treatment algorithm for venous malformations of the limbs.
    No preview · Article · Sep 2015 · Dermatologic Surgery
  • Source
    S Bisdas · C Roder · U Ernemann · M S Tatagiba
    [Show abstract] [Hide abstract]
    ABSTRACT: Intraoperative magnetic resonance imaging (iMRI) has dramatically expanded and nowadays presents state-of-the-art technique for image-guided neurosurgery, facilitating critical precision and effective surgical treatment of various brain pathologies. Imaging hardware providing basic imaging sequences as well as advanced MRI can be seamlessly integrated into routine surgical environments, which continuously leads to emerging indications for iMRI-assisted surgery. Besides the obvious intraoperative diagnostic yield, the initial clinical benefits have to be confirmed by future-controlled long-term studies.
    Full-text · Article · Aug 2015

  • No preview · Article · Aug 2015 · Acta Neurochirurgica
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: PURPOSE: This study was performed to investigate any bilateral differences in the vascular pattern and microsurgical relevant parameters of the superficial temporal artery (STA) in vivo. METHODS: Digital subtraction angiographies of the STA of 38 individuals were retrospectively analyzed. A bilateral comparison of the branching pattern as well as of surgically relevant diameters and lengths of the main branches of the STA was performed. Moreover, gender-specific differences were assessed. RESULTS: Only 10 cases (26 %) demonstrated an identical type and subtype of the STA pattern bilaterally. The diameters of the STA at its origin and bifurcation level as well as of its parietal branch were statistically significant wider on the right than on the left side (p o = 0.0009, p b = 0.006, p p = 0.030). Moreover, the diameters of the STA at its origin level on the right side, at its bifurcation level on both sides and of the frontal branch on both sides were statistically significant wider in males than females. No statistically significant differences of the lengths of the STA and its main branches between the right and the left side were identified. CONCLUSION: The occurrence of the vascular pattern of the STA in vivo is random for each side of the same person and cannot be predicted by the vascular pattern of the opposite side. The calibers of the main branches of the STA are gender specific and commonly larger on the right than on the left side.
    Full-text · Article · Aug 2015 · Surgical and Radiologic Anatomy
  • S Bisdas · C Lá Fougere · U Ernemann
    [Show abstract] [Hide abstract]
    ABSTRACT: Hybrid magnetic resonance (MR)-positron emission tomography (MR-PET) is a novel technology with advantages over sequential MR and PET imaging, allowing maintain full individual diagnostic performance with negligible mutual interference between the two hardware settings. Obvious synergies between MR and PET in acquisition of anatomical, functional, and molecular information for neurological diseases into one single image pave the way for establishing clear clinical indications for hybrid MR-PET as well as addressing unmet neuroimaging needs in future clinics and research. Further developments in attenuation correction, quantification, workflow, and effective MR-PET data management might unfold the full potential of integrated multimodality imaging.
    No preview · Article · Jul 2015
  • [Show abstract] [Hide abstract]
    ABSTRACT: With further increase of CT numbers and their dominant contribution to medical exposure, there is a recent quest for more effective dose control. While re-introduction of iterative reconstruction (IR) has proved its potential in many applications, a novel focus is placed on more noise efficient detectors. Our purpose was to assess the potential of IR in combination with an integrated circuit detector (ICD) for aggressive dose reduction in head CT. Non-contrast low-dose head CT (190 mAs, CTDIvol 33.2 mGy) was performed in fifty consecutive patients, using a new noise efficient detector and IR. Images were assessed in terms of quantitative and qualitative image quality and compared with standard dose acquisitions (320 mAs, CTDIvol 59.7 mGy), using a conventional detector and filtered-back-projection. By combining IC detector and IR in low-dose exams, signal-to-noise was improved by about 13% above baseline level in the standard-dose control group. Both, contrast-to-noise ratio (2.02±0.6 vs. 1.88±0.4; p=0.18) and objective measurements of image sharpness (695± 84 vs.705± 151 Change in HU/Pixel; p=0.79) were fully preserved in the low-dose group. Likewise, there was no significant difference in the grading of several subjective image quality parameters when both noise reducing strategies were used in the low-dose exams. Combination of noise efficient detector with IR allows for meaningful dose reduction in head CT without compromise of standard image quality. Advances in knowledge: Our study demonstrates the feasibility of almost 50% dose reduction in head CT (1.1 mSv per scan) through combination of novel dose reducing strategies.
    No preview · Article · Apr 2015 · The British journal of radiology
  • [Show abstract] [Hide abstract]
    ABSTRACT: To prospectively compare the image quality and diagnostic performance of orbital MR images obtained by using a dual-source parallel transmission (pTX) 3D sequence (Sampling Perfection with Application optimized Contrasts using different flip angle Evolution, SPACE) with the image quality of conventional high-resolution standard protocol for clinical use in patients at 3T. After obtaining institutional review board approval and patient consent, 32 patients with clinical indication for orbital MRI were examined using a high-resolution conventional sequences and 3D pTX SPACE sequences. Quantitative measurements, image quality of the healthy orbit, incidence of artifacts, and the subjective diagnostic performance to establish diagnosis was rated. Statistical significance was calculated by using a Student's t-test and nonparametric Wilcoxon signed rank test. Length measurements were comparable in the two techniques, 3D pTX SPACE resulted in significant faster image acquisition with higher spatial resolution and less motion artifacts as well as better delineation of the optic nerve sheath. However, estimated contrast-to-noise and signal-to-noise and overall image quality as well as subjective scores of the conventional TSE imaging were rated significantly higher. The conventional MR sequences were the preferred techniques by the readers. This study demonstrates the feasibility of 3D pTX SPACE of the orbit resulting in a rapid acquisition of isotropic high-resolution images. Although no pathology was missed in 3D pTX SPACE, conventional MRI techniques showed the higher diagnostic confidence in our study, presumably due to the higher signal-to-noise and contrast-to-noise ratios. We observed high-resolution TSE imaging to be the preferred technique, 3D pTX SPACE cannot replace conventional MRI so far. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    No preview · Article · Mar 2015 · European journal of radiology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Automatic bone and plaque subtraction (BPS) in computed tomographic angiographic (CTA) examinations using dual-energy CT (DECT) remains challenging because of beam-hardening artifacts in the shoulder region and close proximity of the internal carotid artery to the base of the skull. The selection of the tube voltage combination in dual-source CT influences the spectral separation and the susceptibility for artifacts. The purpose of this study was to assess which tube voltage combination leads to an optimal image quality of head and neck DECT angiograms after bone subtraction. Fifty-one patients received tin-filter-enhanced DECT angiograms of the supra-aortic arteries using two voltage protocols: 24 patients were studied using 80/Sn140 kV and 27 using a 100/Sn140 kV protocol, both protocols with an additional tin filter. A commercially available DE-CTA BPS algorithm was used. Artificial vessel erosions in BPS maximum intensity projections (four-level Likert scale with CTA source data as reference) and vessel signal-to-noise ratio (SNR) were assessed in the level of the shoulders and the base of the skull in each patient and compared. At the level of the shoulder, 100/Sn140 kV achieved higher SNR (23.4 ± 6.4 at 80/Sn140 kV vs. 35.1 ± 11.8 at 100/Sn140 kV; P < .0001) with less erosions (erosion score 3.9 ± 0.4 in 80/Sn140 kV vs. 2.1 ± 1.3 in 100/Sn140 kV; P < .0001) than 80/Sn140 kV. At the level of the skull base, erosion scores and objective image quality of arterial segments were comparable with both protocols (P = .14). The 100/Sn140 kV protocol achieved more favorable results for BPS of the supra-aortic arteries than the 80/Sn140 kV protocol. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Mar 2015 · Academic Radiology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background/Study Aims Percutaneous radiofrequency trigeminal rhizotomy (RTR) is a standardized treatment for trigeminal neuralgia, yet it has been associated with serious complications related to the cannulation of the foramen ovale. Some of these complications, such as carotid injury, are potentially lethal. Neuronavigation was recently proposed as a method to increase the procedure's safety. All of the techniques described so far rely on pre- or intraoperative computed tomography scanning. Here we present a simple method based on magnetic resonance imaging (MRI) (radiation free) used to target the foramen ovale under navigation guidance. Patients/Material and Methods We retrospectively analyzed nine patients who had undergone navigated percutaneous RTR based solely on preoperative MRI and compared them with 35 patients who underwent conventional RTR guided by fluoroscopy. We analyzed immediate and late outcome and categorized the results into pain free, > 70% pain reduction, and persistent pain. We also compared groups in terms of the duration of the procedure and the complication rates. Here we describe the navigation method in detail and review the anatomical landmarks for target definition. Results The duration of the surgical procedure was similar in both groups (32.1 in the standard technique versus 34.5 minutes with navigation; p = 0.5157). There was no significant difference between groups regarding pain reduction at the immediate (p = 1.0) or late follow-up (p = 0.6284) time points. Furthermore, no serious complications were observed in the navigated group. Conclusions We present a simple radiation-free method for neuronavigation-assisted percutaneous RTR. This method proved to be safe and effective, and it is especially recommended for young, inexperienced neurosurgeons. Georg Thieme Verlag KG Stuttgart · New York.
    No preview · Article · Jan 2015 · Journal of Neurological Surgery. Part A: Central European Neurosurgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: Magnetic resonance (MR) imaging (MRI) provides information that can be used to estimate the symptom onset in patients with wake-up stroke (WUS). Time-resolved MR angiography (MRA) is the fastest available MR sequence technique for vessel assessment, and the different phases acquired can provide information about cerebral perfusion. The aim of this study was to evaluate the diagnostic performance of time-resolved MRA both for the assessment of vessel morphology and for the feasibility of perfusion. Nineteen patients with WUS were included. Image quality and vessel pathologies were evaluated and correlated to time-of-flight-MRA (n = 14), computed tomography-angiography (n = 4), sonography (n = 12), and conventional angiography (n = 6). The temporal delay of signal enhancement in all pixels of the time-resolved MRA measurement after contrast injection was evaluated and compared to dynamic susceptibility contrast-enhanced (DSC) perfusion imaging (n = 13). Time-resolved MRA resulted in the diagnosis of large vessel disease in 14 of 19 patients, involving the internal carotids (n = 4), the vertebral arteries (n = 3), and the circle of Willis (n = 10). All severe vascular pathologies which influence patients' acute stroke therapy were obtained by time-resolved MRA. Overestimation of stenoses in two of 14 patients resulted in sensitivity and specificity of 100% and 71%, respectively. Time-to-peak (TTP) estimations were hampered by movement artifacts in four patients (31%). Compared to DSC, the area of TTP delay was comparable in size and localization without relevant overestimation or underestimation. Time-resolved MRA is a valuable technique in patients with WUS with high sensitivity and high negative predictive value. Cerebral perfusion estimation can be performed in selected cases for therapy decision but can be hampered by patient movement. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Jan 2015 · Academic radiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Existing anatomic descriptions of the superficial temporal artery (STA) are mainly based on cadaver studies and do not accurately reflect the in vivo situation. In this study, the anatomical course and branching pattern of the STA were analyzed with digital subtraction angiographies (DSAs).MethodsDSAs of 93 Caucasian individuals between 16- and 79-years old were retrospectively analyzed regarding the course and branching pattern of the STA as well as surgically relevant inner diameters and lengths of its main branches.ResultsIn total, 11 variations in the branching pattern of the terminal STA were found. About 89% of the examined individuals demonstrated the classic variation in which the main trunk of the STA bifurcates into a single frontal and parietal branch. In 60% of cases with an existing bifurcation, the division of the main trunk of the STA was located above the zygoma. The mean inner diameters of the STA main trunk, the frontal branch and the parietal branch were 2.4 ± 0.6 mm, 1.3 ± 0.6 mm and 1.2 ± 0.4 mm, respectively. The surgically relevant “working lengths” of the frontal and parietal branches above the upper margin of the zygoma up to an inner diameter of 1 mm were 106.4 ± 62.1mm and 99.7 ± 40.9 mm, respectively.Conclusions The common variations of the branching pattern of the STA are described in this study. Furthermore, surgically relevant inner diameters and lengths of the main branches of the STA are determined. These findings should improve our understanding of the suitability and usefulness of the STA for various surgical procedures. © 2014 Wiley Periodicals, Inc. Microsurgery, 2014.
    Full-text · Article · Oct 2014 · Microsurgery

  • No preview · Conference Paper · Sep 2014
  • Toni Silber · Ulf Ziemann · Ulrike Ernemann · Felix Bischof
    [Show abstract] [Hide abstract]
    ABSTRACT: Background and purpose: Treatment of symptomatic intracranial atherosclerotic disease by angioplasty and stenting (PTAS) is limited by a high rate of periinterventional strokes. We performed a detailed analysis of these strokes at our center in order to identify strategies to reduce the risk of periinterventional complications. Methods: Case records and imaging data of 80 patients with a symptomatic 70-99% stenosis of a major intracranial artery treated with PTAS between July 2007 and December 2013 were reviewed. All patients had a sufficient response to aspirin and clopidogrel. Periinterventional strokes were categorized as either ischemic (perforator territory, distal embolic or delayed stent thrombosis) or hemorrhagic (intraparenchymal, subarachnoid). Results: Periinterventional complications occurred in 6/80 (7.5%) patients, consisting of 2 ischemic strokes (2.5%, both perforator territory), 3 hemorrhagic strokes (3.8%, 2 intraparenchymal due to reperfusion injury, 1 subarachnoid due to vessel rupture) and one death (1.3%) unrelated to stroke. All strokes occurred within 24h after PTAS. Conclusion: Our retrospective data analysis suggests that the risk of periinterventional stroke after PTAS of symptomatic intracranial atherosclerotic disease might be reduced by sufficient antiplatelet therapy and optimized management of patients with high risk for reperfusion injury or perforator strokes, including selection of a stenting device adapted to individual vessel morphology.
    No preview · Article · Sep 2014 · European Journal of Radiology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Rationale and Objectives: A new computed tomography (CT) detector with integrated electric components and shorter conducting pathways has recently been introduced to decrease system inherent eleotronic noise. The purpose of this study was to-assess the potential benefit of Such integrated circuit detector (ICD) in head CT by comparing objective and subjective image quality in low dose examinations with a conventional detector design. Materials and Methods: Using a conventional detector, reduced-dose noncontrast head CT (255 mAs; effective dose, 1.7 mSv) was performed in 25 consecutive patients. Following transition to ICD; 25 consecutive-patients were scanned using identical imaging parameters. Images in both groups were reconstructed with iterative reconstruction (IR) and filtered back projection (FBP) and assessed in terms of quantitative and qualitative image quality. Results: Acquisition of head CT using ICD increased Signal-to-noise ratio of gray and white matter by 14% (10.0 +/- 1.6 vs. 11.4 +/- 2.5; P = .02) and 17% (8.2 +/- 0.8 vs. 9.6 +/- 1.5; P = .000). The associated improvement in contrast-to-noise ratio was 12% (2.0 +/- 0.5 vs. 2.2 +/- 0.6; P = .121). In addition, there was a 51% increase in objective image sharpness (582 +/- 85 vs. 884.5 +/- 191; change in HU/Pixel; P < .000). Compared to standard acquisitions, subjective grading of noise and overall image quality scores were significantly improved with ICD (2.1 +/- 0.3 vs. 1.6 +/- 0.3; P < .000; 2.0 +/- 0.5 vs. 1.6 +/- 0.3; P = .001). Moreover, streak artifacts in the posterior fossa were substantially reduced (2.3 +/- 0.7 vs. 1.7 +/- 0.5; P = .004) Conclusions: At the same radiation level, acquisition of head CT with ICD achieves superior objective and subjective. image quality and provides potential for significant dose reduction.
    No preview · Article · Sep 2014 · Academic Radiology
  • A Seeger · U Klose · F Bischof · J Strobel · U Ernemann · T-K Hauser
    [Show abstract] [Hide abstract]
    ABSTRACT: Purpose: A new method for diffusion-weighted imaging (DWI) using independent parallel transmission technique resulting in zoomed DWI was applied in four patients suffering from acute spinal cord ischemia. Methods: Four patients with clinical symptoms of acute spinal cord ischemia were examined on a 3 T MR-system equipped with a two-channel transmit array. Scans included T2-weighted turbo spin echo, conventional DWI, and zoomed DWI. Image evaluation was performed with regard to overall image quality, anatomic delineation of the spinal cord, and the level of confidence to establish the diagnosis of spinal cord ischemia. Results: Through spatially selective excitation, zoomed DWI allows for acquisition of high-resolution images with reduced scan time due to a reduced field of view in phase-encoding direction, resulting in zoomed images. In all cases the ischemia was demonstrated in conventional DWI as well as zoomed DWI. Conclusions: Compared to conventional DWI, zoomed DWI enables a faster image acquisition and allowed a more detailed analysis of the spinal lesion which may be critical to attribute the lesion to a particular vessel territory.
    No preview · Article · Aug 2014 · Clinical Neuroradiology

Publication Stats

3k Citations
612.61 Total Impact Points

Institutions

  • 2000-2015
    • Universitätsklinikum Tübingen
      • • Division of Diagnostic and Interventional Neuroradiology
      • • Division of Neurourology
      • • Division of General neurology
      • • Department of Neurosurgery
      • • Hospital and Policlinic for Oral and Maxillofacial Surgery
      Tübingen, Baden-Württemberg, Germany
    • Deutsche Gesellschaft für Mund-, Kiefer- und Gesichtschirurgie e.V.
      Tübingen, Baden-Württemberg, Germany
  • 1997-2015
    • University of Tuebingen
      • • Department of Neurology
      • • Department of Internal Medicine
      Tübingen, Baden-Württemberg, Germany
  • 2009
    • University of Bonn
      Bonn, North Rhine-Westphalia, Germany
  • 2008
    • University of Freiburg
      Freiburg, Baden-Württemberg, Germany