Susanne C Ladd

University Hospital Essen, Essen, North Rhine-Westphalia, Germany

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Publications (113)209.92 Total impact

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    ABSTRACT: Object: Over the last decade, the number of clinical MRI studies at 7 T has increased dramatically. Since only limited information about the safety of implants/tattoos is available at 7 T, many centers either conservatively exclude all subjects with implants/tattoos or have started to perform dedicated tests for selected implants. This work presents our experience in imaging volunteers with implants/tattoos at 7 T over the last seven and a half years. Materials and methods: 1796 questionnaires were analyzed retrospectively to identify subjects with implants/tattoos imaged at 7 T. For a total of 230 subjects, the type of local transmit/receive RF coil used for examination, imaging sequences, acquisition time, and the type of implants/tattoos and their location with respect to the field of view were documented. These subjects had undergone examination after careful consideration by an internal safety panel consisting of three experts in MR safety and physics. Results: None of the subjects reported sensations of heat or force before, during, or after the examination. None expressed any discomfort related to implants/tattoos. Artifacts were reported in 52 % of subjects with dental implants; all artifacts were restricted to the mouth area and did not affect image quality in the brain parenchyma. Conclusion: Our initial experience at 7 T indicates that a strict rejection of subjects with tattoos and/or implants is not justified. Imaging can be conditionally performed in carefully selected subjects after collection of substantial safety information and evaluation of the detailed exposure scenario (RF coil/type and position of implant). Among the assessed subjects with tattoos, no side effects from the exposure to 7 T MRI were reported.
    MAGMA Magnetic Resonance Materials in Physics Biology and Medicine 09/2015; 28(6). DOI:10.1007/s10334-015-0499-y · 2.87 Impact Factor
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    ABSTRACT: Purpose To detail the rationale, design, and future perspective of implementing whole-body magnetic resonance (MR) imaging in the German National Cohort, a large multicentric population-based study. Materials and Methods All institutional review boards approved the study, and informed consent is obtained before study enrollment. Participants are enrolled from a random sample of the general population at five dedicated imaging sites among 18 recruitment centers. MR imaging facilities are equipped with identical 3.0-T imager technology and use uniform MR protocols. Imager-specific hardware and software settings remained constant over the study period. On-site and centralized measures of image quality enable monitoring of completeness of the acquisitions and quality of each of the MR sequences. Certified radiologists read all MR imaging studies for presence of incidental findings according to predefined algorithms. Results Over a 4-year period, six participants per day are examined at each center, totaling a final imaging cohort of approximately 30 000 participants. The MR imaging protocol is identical for each site and comprises a set of 12 native series to cover neurologic, cardiovascular, thoracoabdominal, and musculoskeletal imaging phenotypes totaling approximately 1 hour of imaging time. A dedicated analysis platform as part of a central imaging core incorporates a thin client-based integrative and modular data handling platform to enable multicentric off-site image reading for incidental findings. Scientific analysis will be pursued on a per-project hypothesis-driven basis. Conclusion Population-based whole-body MR imaging as part of the German National Cohort will serve to compile a comprehensive image repository, will provide insight into physiologic variants and subclinical disease burden, and has the potential to enable identification of novel imaging biomarkers of risk. (©) RSNA, 2015 Online supplemental material is available for this article.
    Radiology 05/2015; 277(1):142242. DOI:10.1148/radiol.2015142272 · 6.87 Impact Factor
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    ABSTRACT: Background To evaluate the benefit (additional flow information), image quality, and diagnostic accuracy of a dynamic magnetic resonance angiography (MRA) combining high spatial and temporal resolution for the preinterventional assessment of acute aortic dissection.Methods Nineteen patients (12 men, 7 women; aged 32–78 years) with acute aortic dissection underwent contrast-enhanced four-dimensional (4D) MRA and 3D conventional high-resolution MRA (3D MRA) within one examination on a 1.5 Tesla MR system. Both MRA datasets for each patient were evaluated and compared for image quality and visualization of vascular details on a 5-point scale (5 = excellent image quality, 1 = nondiagnostic image quality). In addition, presence and relevance of additional hemodynamic information (flow direction and organ perfusion delay) gained by dynamic MRA were assessed.ResultsConventional 3D MRA provided significantly higher values for image quality of the aorta and aortic side branches compared with dynamic MRA (aorta: 4.3 versus 3.3; P = 0.006 side branches: 4.2 versus 3.3; P = 0.02). However, in 10 of the 19 patients (53%) the additionally available information on flow dynamics due to dynamic MRA (e.g., delayed perfusion of parenchymal organs) led to a change in therapy planning and realization.Conclusion Dynamic MRA is a technique that combines functional flow and morphological information. Thus, the combination of 3D and dynamic MRA provides all requested information for treatment planning in patients suffering from acute aortic dissection. J. Magn. Reson. Imaging 2014.
    Journal of Magnetic Resonance Imaging 11/2014; 42(2). DOI:10.1002/jmri.24788 · 3.21 Impact Factor
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    ABSTRACT: Ultra-high-field MRI (7 Tesla (T) and above) elicits more temporary side-effects compared to 1.5 T and 3 T, e.g. dizziness or "postural instability" even after exiting the scanner. The current study aims to assess quantitatively vestibular performance before and after exposure to different MRI scenarios at 7 T, 1.5 T and 0 T. Sway path and body axis rotation (Unterberger's stepping test) were quantitatively recorded in a total of 46 volunteers before, 2 minutes after, and 15 minutes after different exposure scenarios: 7 T head MRI (n = 27), 7 T no RF (n = 22), 7 T only B0 (n = 20), 7 T in & out B0 (n = 20), 1.5 T no RF (n = 20), 0 T (n = 15). All exposure scenarios lasted 30 minutes except for brief one minute exposure in 7 T in & out B0. Both measures were documented utilizing a 3D ultrasound system. During sway path evaluation, the experiment was repeated with eyes both open and closed. Sway paths for all long-lasting 7 T scenarios (normal, no RF, only B0) with eyes closed were significantly prolonged 2 minutes after exiting the scanner, normalizing after 15 minutes. Brief exposure to 7 T B0 or 30 minutes exposure to 1.5 T or 0 T did not show significant changes. End positions after Unterberger's stepping test were significantly changed counter-clockwise after all 7 T scenarios, including the brief in & out B0 exposure. Shorter exposure resulted in a smaller alteration angle. In contrast to sway path, reversal of changes in body axis rotation was incomplete after 15 minutes. 1.5 T caused no rotational changes. The results show that exposure to the 7 Tesla static magnetic field causes only a temporary dysfunction or "over-compensation" of the vestibular system not measurable at 1.5 or 0 Tesla. Radiofrequency fields, gradient switching, and orthostatic dysregulation do not seem to play a role.
    PLoS ONE 03/2014; 9(3):e92104. DOI:10.1371/journal.pone.0092104 · 3.23 Impact Factor
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    ABSTRACT: The aims of this study were to investigate the subjective discomfort and sensory side effects during ultrahigh field (UHF) magnetic resonance imaging (MRI) examinations in a large-scale study and to evaluate differences between magnetic resonance (MR) sites. Four MR sites with a 7-T MR system and 2 MR sites with a 9.4-T MR system participated in this multicenter study with a total number of 3457 completed questionnaires on causes of discomfort and sensations during the examination. For a pooled retrospective analysis of the results from the partially different questionnaires, all data were adapted to an answer option with a 4-point scale (0 = no discomfort/side effect, 3 = very unpleasant/very strong sensation). To differentiate effects evoked by the low-frequency time-varying magnetic fields due to movement through the static magnetic field, most questionnaires separated the manifestation of sensory side effects during movement on the patient table from manifestation while lying still in the isocenter. In general, a high acceptance of UHF examinations was found, where in 82% of the completed questionnaires, the subjects stated the examination to be at least tolerable. Although in 7.6% of the questionnaires, subjects felt discomfort during the examination, only 0.9% of the image acquisitions had to be terminated prematurely. No adverse events occurred in any of the examinations. Only 1% of the subjects were unwilling to undergo further UHF MRI examinations. Examination duration was the most complained cause of discomfort, followed by acoustic noise and lying still. All magnetic-field-related sensations were more pronounced when moving the patient table versus the isocenter position (19%/2% of the subjects felt unpleasant vertigo during the moving/stationary state). In general, vertigo was the most often stated sensory side effect and was more pronounced at 9.4 T compared with 7 T. However, the results varied substantially among the different sites. The high levels of subjective acceptance found in this study lead to the conclusion that UHF MRI would be tolerated as a diagnostic tool in clinical practice. For more consistent data ascertainment, we propose a standardized questionnaire for subjective perception monitoring.
    Investigative radiology 03/2014; 49(5). DOI:10.1097/RLI.0000000000000035 · 4.44 Impact Factor
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    ABSTRACT: Introduction: Our purpose was to analyze the long-term evolution of wide neck cerebral aneurysms treated with stent assistance. Methods: Data of consecutive patients treated with the Neuroform stent over 9 years were retrospectively analyzed with emphasis on periprocedural complications, aneurysm occlusion grade evolution, and in-stent stenosis rates. Results: Altogether, 113 patients with 117 unruptured and ruptured aneurysms were subject of analysis. Mean aneurysm size was 9.4 mm, and mean neck size was 4.7 mm. Procedural thromboembolic and hemorrhagic complications affected eight (6.8%) and four cases (3.4%), respectively. Immediate complete occlusion and occlusion with residual neck was achieved in 85% of cases, which at the first follow-up of 6 months, changed to 77 and 76 % at 36 months. Aneurysms ≥10 mm showed a higher tendency of recurrence. During the overall follow-up time ranging from 1 to 9 years, an in-stent stenosis of ≥50 % was observed only in three cases, all of them being asymptomatic. Conclusions: Stent-assisted coiling of wide neck aneurysms provided stable occlusion over the long-term follow-up, with very low and silent in-stent stenosis rates. Some incompletely occluded aneurysms showed a tendency of progressive occlusion; however, this was counterbalanced by the regrowth of others.
    Neuroradiology 01/2013; 55(4). DOI:10.1007/s00234-013-1143-z · 2.49 Impact Factor
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    ABSTRACT: PURPOSE MRI including high field (up to 3 Tesla) is known as a safe diagnostic imaging procedure without harmful long-term effects. Transient side effects are reported more frequently at higher fields; in particular, some subjects report a subjective postural instability after the examination, which this study assesses quantitatively at 7T. METHOD AND MATERIALS Fifty healthy volunteers (35m, 15f, mean age 33y) underwent a Romberg’s test before, 2-5 min after, and 15 min after 7T MRI, at different exposure scenarios (30 min each): (1) complete (B0, gradients, RF); (2) B0 with gradients, without RF; (3) neither RF nor gradient switching (subgroup n=20); (4) control without MR exposure; in addition: (5) only movement into the center of the magnet and back out (0 min scan time, subgroup n=20). Volunteers were asked to stand on a 20 cm thick foam cushion with feet close together and with eyes open or closed to minimize information from the proprioceptive and/ or visual system and to maximize use of the vestibular system. An ultrasound real-time measuring system recorded the 3D position and sway path length of a transmitter fixated to the lumbar spine during 30s. Data were compared for different time points, MR settings, and eyes open or closed. RESULTS Sway path length of the lumbar spine showed no significant differences before, 2-5 min after and 15 min after any scenario when eyes were open. With eyes closed significant changes occurred after (1) complete exposure at 2 min versus baseline and normalized after 15 min. A similar tendency (borderline significance) was also apparent for exposure with gradients but no RF (2). Significant effects were noted neither in the subgroup without RF and without gradients (3), nor in the control group (4) nor in the setting (5). CONCLUSION Exposure to a head 7 Tesla MRI causes only a temporary dysfunction or over-compensation of the vestibular system. B0 (including dB0/dt during table movement) and gradients seem to have an influence on postural stability, whereas RF does not seem to exhibit a significant influence. Further studies are needed to differentiate between the effects of B0, dB0/dt and the gradients. CLINICAL RELEVANCE/APPLICATION Evaluating temporary side effects of 7 Tesla MRI is mandatory before transferring it into diagnostic routine. This study supports its safeness and renders deeper insight into underlying mechanisms.
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
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    ABSTRACT: Up to about one-quarter of patients treated with neoadjuvant chemotherapy do not adequately respond to the given treatment. By a differentiation between responders and non-responders ineffective toxic therapies can be prevented. To retrospectively test if FDG-PET/CT is able to early differentiate between breast cancer lesions with pathological complete response (pCR) and lesions without pathological complete response (npCR) after two cycles of neoadjuvant chemotherapy (NACT). In this retrospective study 26 breast cancer patients (mean age, 46.9 years ± 9.9 years) underwent a pre-therapeutic FDG-PET/CT scan and a subsequent FDG-PET/CT after the second cycle of NACT. Histopathology of resected specimen served as the reference standard. Maximum standardized uptake values (SUVmax) of cancer lesions before and after the second cycle of NACT were measured. Two evaluation algorithms were used: (a) pCR: Sinn Score 3 and 4, npCR: Sinn Score 0-2; (b) pCR: Sinn Score 4, npCR: Sinn Score 0-3. The absolute and relative decline of the SUVmax (ΔSUVmax, ΔSUVmax(%))was calculated. Differences of the SUVmax as well as of the SUVmax decline between pCR lesions and npCR lesions were tested for statistical significance P < 0.05. To identify the optimal cut-off value of ΔSUVmax(%) to differentiate between pCR lesions and npCR lesions a receiver-operating curve (ROC) analysis was performed. Using evaluation algorithm A the ΔSUVmax was 13.5 (pCR group) and 3.9 (npCR group) (P = 0.006); the ΔSUVmax(%) was 79% and 47%, respectively (P = 0.001). On ROC analysis an optimal cut-off ΔSUVmax(%) of 66% was found. Using evaluation algorithm B the ΔSUVmax was 17.5 (pCR group) and 4.9 (npCR group) (P = 0.013); the ΔSUVmax(%) was 89% and 51%, respectively (P = 0.003). On ROC analysis an optimal cut-off ΔSUVmax(%) of 88% was found. FDG-PET/CT may be able to early differentiate between pCR and npCR of primary breast cancer lesions after two cycles of NACT.
    Acta Radiologica 07/2012; 53(6):628-36. DOI:10.1258/ar.2012.110699 · 1.60 Impact Factor
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    ABSTRACT: Objective: To present imaging characteristics of the ankle at 7.0 T and to investigate the appearance and image quality of presumed pathologies of ankles without physical strain as well as of ankles after a marathon run in comparison to 1.5 T. Materials and methods: Appearance of presumed pathologic findings and image quality of TSE (PD, T2, and STIR) and GRE sequences (MEDIC, DESS, and/or CISS) at 7.0 T and 1.5 T MRI were compared by two senior radiologists in consensus in two healthy controls without strain and in six marathon runners after a full-length marathon (eight males, mean age 49.1 years). Results: Overall, 7.0 T MRI allowed for higher resolution images for most of the sequences while requiring comparable acquisition times and achieving high contrast images mainly in gradient echo sequences. Bursal or presumed peritendineal fluid and/or edematous tissue, which were found in seven of eight subjects, could be best appreciated with 7.0 T MEDIC. Other findings with sharper delineation at 7.0 T included cartilage defects (best: CISS), osseous avulsions, and osteophytes (best: DESS). Nevertheless, 1.5 T STIR imaging enabled assessment of a tibiotalar bone edema-like lesion in two runners, which was barely visible at 7.0 T using STIR, but not with any other sequence at 7.0 T including MEDIC (with frequency selective fat suppression). 7.0 T showed larger image quality variations with challenges especially in the TSE sequences. Conclusion: Our initial results of ultra-high-field ankle joint imaging demonstrate the improved depiction of ankle anatomy, fluid depositions, and cartilage defects. However imaging of edema-like bone lesions remains challenging at ultra-high magnetic field strength, and TSE coverage in particular is limited by the specific absorption rate.
    Skeletal Radiology 06/2012; 42(2). DOI:10.1007/s00256-012-1454-x · 1.51 Impact Factor
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    ABSTRACT: To evaluate the diagnostic performance of T2-weighted magnetic resonance (MR) cholangiopancreatography pulse sequences in comparison with MR cholangiopancreatography sequences combined with nonenhanced T1-weighted images in the detection of biliary cast syndrome in liver transplant recipients. This retrospective study was conducted in accordance with the declaration of Helsinki. Institutional review board approval was obtained. MR images in 95 patients who were examined after liver transplantation and who presented with symptoms of biliary obstruction were examined. Two separate sets of images, MR cholangiopancreatograms and MR cholangiopancreatograms plus T1-weighted images, were evaluated independently by three readers. Sensitivities, specificities, and positive and negative predictive values for biliary cast syndrome were calculated, and receiver operating characteristic curves were generated. The results of endoscopic retrograde cholangiopancreatography served as the reference standard. To determine interobserver agreement, κ values were calculated. Cast appeared hyperintense on nonenhanced T1-weighted images. Sensitivities for T2-weighted MR cholangiopancreatography data alone were 0.65, 0.70, and 0.55 for the three readers. Adding unenhanced T1-weighted images resulted in sensitivities of 0.95, 0.90, and 0.90, respectively. Specificities for MR cholangiopancreatography alone and for MR cholangiopancreatography plus T1-weighted images were high on average (0.98, 0.97, and 0.97 vs 1.0 for all readers, respectively). Interobserver agreement was good for T2-weighted MR cholangiopancreatography (κ for readers 1 and 2 = 0.589, κ for readers 2 and 3 = 0.593, κ for readers 1 and 3 = 0.734) and was excellent for MR cholangiopancreatography plus T1-weighted images (κ for readers 1 and 2 = 0.806, κ for readers 2 and 3 = 0.881, κ for readers 1 and 3 = 0.848). The combination of T2-weighted MR cholangiopancreatography and T1-weighted imaging yields higher diagnostic performance than MR cholangiopancreatography alone. Therefore, readers evaluating liver MR images with regard to biliary complications after liver transplantation should also look at the bile ducts on unenhanced T1-weighted images, as biliary cast might be more easily depicted on these images.
    Radiology 05/2012; 263(2):429-36. DOI:10.1148/radiol.12111625 · 6.87 Impact Factor

  • RöFo - Fortschritte auf dem Gebiet der R 05/2012; 184(S 01). DOI:10.1055/s-0032-1311309 · 1.40 Impact Factor

  • RöFo - Fortschritte auf dem Gebiet der R 05/2012; 184(S 01). DOI:10.1055/s-0032-1311213 · 1.40 Impact Factor
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    ABSTRACT: A study on subjective perception has been carried out in order to gain further insight into subjective discomfort and sensations experienced during 7 T magnetic resonance imaging (MRI). This study provides information about subjective acceptance, which is essential if 7 T MRI is to become a clinical diagnostic tool. Of 573 subjects who underwent 7 T MRI, 166 were also examined at 1.5 T, providing a means of discriminating field-dependent discomfort. All subjects judged sources of discomfort and physiological sensations on an 11-point scale (0 = no side effects, 10 = intolerable side effects) and scores were analyzed separately for exam phases, with and without table movement at each field strength. Results revealed that 7 T MRI was, in general, judged more uncomfortable than 1.5 T; however, most subjects rated the effects as being non-critical (mean scores between 0.5 and 3.5). Significant differences were detected regarding vertigo and sweating between subjects positioned "head-first" and "feet-first" at 7 T (worse in "head-first") and between 7 and 1.5 T (worse at 7 T), with the effects being more pronounced in the moving compared to the stationary table position. The most unpleasant factor at 7 T was the extensive examination duration, while potentially field-dependent sensations were rated less bothersome. In summary, our study indicates that although certain sensations increase at 7 T compared to 1.5 T, they are unlikely to hinder the use of 7 T MRI as a clinical diagnostic tool.
    Bioelectromagnetics 12/2011; 32(8):610-9. DOI:10.1002/bem.20680 · 1.71 Impact Factor
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    ABSTRACT: To assess the survival of patients with hepatic uveal melanoma metastases undergoing sequential transarterial hepatic chemoperfusion. 61 patients (mean age, 60.3 ± 13.8 y) underwent a total of 249 hepatic chemoperfusion procedures (mean: 4 chemoperfusion procedures; range, 1-7 chemoperfusion procedures; standard deviation, 2.3 chemoperfusion procedures). All patients started with melphalan. In the case of progressive disease, melphalan was replaced by a different chemoperfusion agent. 38 patients were treated with melphalan only, 23 patients were treated with a combination of melphalan and other drugs. The median overall survival time was calculated for the overall population and several sub-groups. Differences in the survival rate between the sub-groups were assessed for statistical significance. The complication rate was assessed. The median overall survival of the entire population was 10 months. The patients in the subgroups with a maximum number of 9 hepatic metastases as well as the patients in the subgroup without extrahepatic metastases at the beginning of therapy survived significantly longer than patients with more than 9 metastases/extrahepatic metastases (p = 0.019, p = 0.008). One patient (0.4%) died from liver failure after initial infusion of melphalan. Intraarterial sequential hepatic chemoperfusion offers a minimally invasive treatment in patients with hepatic uveal melanoma metastases with good survival times and an acceptable major complication rate.
    RöFo - Fortschritte auf dem Gebiet der R 12/2011; 183(12):1151-60. DOI:10.1055/s-0031-1281743 · 1.40 Impact Factor
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    ABSTRACT: PURPOSE The aim of this study was to evaluate the feasibility of non-enhanced and contrast-enhanced (CE-) MRA of the abdominal vasculature at 7 Tesla field strength. METHOD AND MATERIALS MR examinations were performed in 31 healthy volunteers on a 7T whole-body MR system (Magnetom 7T, Siemens Healthcare), utilizing a custom-built 8-channel transmit/receive radiofrequency (RF) body coil for image acquisition. After RF shimming and sequence modification, the following sequences were obtained: 1) 2D FLASH, 2) 3D FLASH, and 3) TOF-MRA. For dynamic imaging Gadobutrol (Gadovist®, Bayer Schering Pharma) was injected intravenously at a dosage of 0.1 mmol/kg body weight using an automated injector (EMPOWER MR®, EZEM) and 3 dynamic 3D FLASH sequences were obtained (arterial, portal-venous and venous phase). Qualitative analysis with regards to renal and hepatic vessel delineation was performed using a five-point-scale (5=excellent to 1=non diagnostic). RESULTS The inherently high signal intensity of the abdominal arterial vasculature in T1w imaging enabled a moderate to excellent vessel delineation in all non-enhanced sequences. Visual analysis revealed the diagnostic superiority of TOF MRA among the non-enhanced sequences (mean 4.7 in all vessel segments) and its diagnostic equivalence to contrast-enhanced MRA (mean 4.8). While non-enhanced 3D FLASH MRI showed moderate delineation of the hepatic (3.0) and renal (3.4) arteries and good conspicuity of the portal veins (3.7), venous vasculature showed only poor contrast (mean 1.9). 2D FLASH imaging revealed a moderate conspicuity of all assessed vessel segments with reasonable impairment due to signal variations associated with residual inhomogeneities of B1-shimming. CONCLUSION This pilot study demonstrates the feasibility of in vivo contrast-enhanced ultra-high-field MRA. Non-enhanced T1w imaging in general and especially TOF MRA appear to be promising techniques for good quality non-enhanced vasculature evaluation. This may be of high diagnostic interest in patients with renal insufficiency, considering the issue of Nephrogenic Systemic Fibrosis. CLINICAL RELEVANCE/APPLICATION Non-enhanced T1w imaging, especially TOF MRA, appear to be promising techniques for assessment of vessel pathologies in patients with contraindications to the application of gadolinium.
    Radiological Society of North America 2011 Scientific Assembly and Annual Meeting; 11/2011
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    ABSTRACT: Two different forms of biliary anastomosis can be created in patients undergoing liver transplantation: (a) bilio-digestive anastomoses or (b) choledocho-choledochostomy. Aim of this study was to assess the accuracy of MR cholangiopancreatography (MRCP) for the depiction of biliary stenoses in liver transplant patients depending on the type of biliary anastomosis. 24 liver transplant patients with clinical suspicion of biliary stenosis were studied (each 12 with bilio-digestive anastomosis/choledocho-choledochostomy). MRCP was performed on a 1.5 T scanner (Magnetom Avanto, Siemens) including 2D single shot RARE, 2D T2w HASTE, TrueFISP and 3D high-resolution navigator corrected sequences. Presence of (a) anastomotic stenoses (AST) and (b) NAS (non-anastomotic strictures) were assessed. Percutaneous transhepatic cholangiography (PTC) or endoscopic retrograde cholangiopancreatography (ERCP) were performed within 48h after MRCP and served as the standard of reference. In patients with bilio-digestive anastomoses sensitivities of MRCP for the detection of AST and NAS amounted to 50% and 67%, respectively with specificity values of 83% and 50%. In patients with choledocho-chledochostomy sensitivities (AST: 100%, NAS: 100%) and specificities (AST: 100%, NAS: 88%) were significantly higher. Biliary strictures after liver transplantation can be accurately detected by MRCP in patients after choledocho-chledochostomy. However, the diagnostic value of MRCP is lower if liver transplantation was performed in combination with a bilio-digestive anastomosis. This may be due to the less exact depiction of the anastomosis in the bowel wall. Thus, it is crucial to know the type of biliary anastomosis before choosing a diagnostic procedure.
    European journal of radiology 11/2011; 80(2):e20-8. DOI:10.1016/j.ejrad.2010.06.003 · 2.37 Impact Factor
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    ABSTRACT: To assess the survival time of patients with HCC following transarterial chemoembolization performed in a highly selective and sequential way. 124 HCC patients (102 male, 22 female; mean age 63±11 years) treated with selective and sequential chemoembolization at a single center were included. Selective chemoembolization was performed through a coaxially introduced microcatheter in a segmental or subsegmental hepatic artery. Treatment was stopped after complete stasis of the blood flow in the tumor-feeding vessel. The primary endpoint of the study was overall survival. The median overall survival of the entire patient population was 27.2 months (mo) (±8.9 mo, 95% CI 9.8 mo, 44.6 mo). When stratified according to liver function the median survival was 46.1 mo (±9.0 mo; 95% CI 28.5 mo, 63.7 mo) for Child-Pugh A and 11.1 mo (±4.3 mo; 95% CI 2.7 mo, 19.5 mo) for Child-Pugh B (p<.001). The median survival was 46.1 mo (±16.6 mo; 95% CI 13.5 mo, 78.7 mo) for BCLC stage A, 19.7 mo (±2.6 mo; 95% CI 14.6 mo, 24.8 mo) for BCLC stage B, and 14.4 mo (±5.0 mo; 95% CI 4.5 mo, 24.3 mo) for BCLC stage C (p<.01). Selective and sequential chemoembolization offers long survival times in patients with HCC. Those patients with preserved liver function benefit more than patients with limited liver reserve.
    European journal of radiology 10/2011; 81(9):2290-7. DOI:10.1016/j.ejrad.2011.09.010 · 2.37 Impact Factor
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    ABSTRACT: The aim of this study was to investigate the feasibility of dynamic contrast-enhanced 7T MRI of the liver using an eight-channel radiofrequency (RF) transmit/receive body-coil. 16 healthy subjects were examined on a 7T MR system utilizing a custom-built eight-channel RF body-coil suitable for RF-shimming. The following data were acquired: (1) steady state free precession imaging, (2) T2w turbo spin echo imaging, (3) T1w in and opposed-phase imaging, (4) T1w 3D FLASH images pre-contrast and in arterial, portal-venous and venous phase and (5) a fat-saturated pre- and post-contrast 2D FLASH sequence. Visual evaluation of (1) the delineation of liver vasculature, (2) the overall image quality, and (3) artifact presence and consequent image impairment was performed. SNR of the liver parenchyma was measured for the contrast-enhanced 2D and 3D FLASH sequences. For statistical analysis, a Wilcoxon-Rank Test was used. Best delineation of non-enhanced liver vasculature and overall image quality was found for 2D FLASH MRI, with only slight improvement in vessel conspicuity after the application of contrast media. T2-weighted TSE imaging remained strongly impaired, falling short of diagnostic relevance and precluding a clinical application. Our results demonstrate the feasibility and diagnostic potential of dedicated contrast-enhanced 7T liver MRI as well as the potential for non-contrast-enhanced angiographic application.
    European journal of radiology 08/2011; 82(5). DOI:10.1016/j.ejrad.2011.07.004 · 2.37 Impact Factor
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    ABSTRACT: To evaluate 7T MRI in the assessment of cerebrovascular alterations as seen in vascular dementia by means of detection of cerebral microbleeds (CMB) and depiction of white matter lesions (WML). 7T imaging was evaluated with respect to 1.5T. Ten healthy volunteers and 10 patients with CMBs and/or WMLs were examined at 1.5T and 7T using gradient-echo (T2*, SWI) and turbo-spin-echo sequences (FLAIR). Comparisons of image quality, CMB and WML detection rates between sequences and field strengths were performed. Using high-resolution SWI at 7T 129 CMBs were detected compared to 75 at 1.5T using clinical SWI. With T2* at 7T 101 CMBs could be detected (33 CMBs at 1.5T). Lesion sizes were significantly larger for higher field strength. FLAIR images at 7T highlighted WMLs known from 1.5T with comparable extent. Gray and white matter contrast in FLAIR was slightly better at 1.5T, whereas image resolution and contrast of the WMLs to surrounding tissue was higher at 7T. By means of higher sensitivity for CMBs, 7T (SWI, T2*) might have significant impact on the early detection, diagnosis, and optimized antithrombotic therapy of cerebrovascular patients (eg, vascular dementia) in the future. Given the current state of technical development, 7T is approximately on par with 1.5T in the depiction of WMLs and their distribution, but holds the potential for future improvements.
    Journal of Magnetic Resonance Imaging 04/2011; 33(4):782-91. DOI:10.1002/jmri.22513 · 3.21 Impact Factor
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    ABSTRACT: To investigate the feasibility of 7T MR imaging of the kidneys utilising a custom-built 8-channel transmit/receive radiofrequency body coil. In vivo unenhanced MR was performed in 8 healthy volunteers on a 7T whole-body MR system. After B(0) shimming the following sequences were obtained: 1) 2D and 3D spoiled gradient-echo sequences (FLASH, VIBE), 2) T1-weighted 2D in and opposed phase 3) True-FISP imaging and 4) a T2-weighted turbo spin echo (TSE) sequence. Visual evaluation of the overall image quality was performed by two radiologists. Renal MRI at 7T was feasible in all eight subjects. Best image quality was found using T1-weighted gradient echo MRI, providing high anatomical details and excellent conspicuity of the non-enhanced vasculature. With successful shimming, B(1) signal voids could be effectively reduced and/or shifted out of the region of interest in most sequence types. However, T2-weighted TSE imaging remained challenging and strongly impaired because of signal heterogeneities in three volunteers. The results demonstrate the feasibility and diagnostic potential of dedicated 7T renal imaging. Further optimisation of imaging sequences and dedicated RF coil concepts are expected to improve the acquisition quality and ultimately provide high clinical diagnostic value.
    European Radiology 04/2011; 21(4):841-9. DOI:10.1007/s00330-010-1962-9 · 4.01 Impact Factor

Publication Stats

1k Citations
209.92 Total Impact Points


  • 2006-2014
    • University Hospital Essen
      • Institute of Diagnostic and Interventional Radiology and Neuroradiology
      Essen, North Rhine-Westphalia, Germany
  • 2007-2012
    • University of Duisburg-Essen
      • Erwin L. Hahn Institute for Magnetic Resonance Imaging
      Essen, North Rhine-Westphalia, Germany
  • 2008-2009
    • Katholisches Klinikum Essen
      Essen, North Rhine-Westphalia, Germany