Ulrike I Attenberger

Universität Mannheim, Mannheim, Baden-Württemberg, Germany

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Publications (143)305.33 Total impact

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    ABSTRACT: Background: Simultaneous PET/MR imaging depends on MR-derived attenuation maps (mu-maps) for accurate attenuation correction of PET data. Currently, these maps are derived from gradient-echo-based MR sequences, which are sensitive to susceptibility changes. Iron oxide magnetic nanoparticles have been used in the measurement of blood volume, tumor microvasculature, tumor-associated macrophages, and characterizing lymph nodes. Our aim in this study was to assess whether the susceptibility effects associated with iron oxide nanoparticles can potentially affect measured (18)F-FDG PET standardized uptake values (SUV) through effects on MR-derived attenuation maps. Methods: The study protocol was approved by the Institutional Animal Care and Use Committee. Using a Siemens Biograph mMR PET/MR scanner, we evaluated the effects of increasing concentrations of ferumoxytol and ferumoxytol aggregates on MR-derived mu-maps using an agarose phantom. In addition, we performed a baboon experiment evaluating the effects of a single i.v. ferumoxytol dose (10 mg/kg) on the liver, spleen, and pancreas (18)F-FDG SUV at baseline (ferumoxytol-naïve), within the first hour and at 1, 3, 5, and 11 weeks. Results: Phantom experiments showed mu-map artifacts starting at ferumoxytol aggregate concentrations of 10 to 20 mg/kg. The in vivo baboon data demonstrated a 53% decrease of observed (18)F-FDG SUV compared to baseline within the first hour in the liver, persisting at least 11 weeks. Conclusions: A single ferumoxytol dose can affect measured SUV for at least 3 months, which should be taken into account when administrating ferumoxytol in patients needing sequential PET/MR scans. Advances in knowledge 1. Ferumoxytol aggregates, but not ferumoxytol alone, produce significant artifacts in MR-derived attenuation correction maps at approximate clinical dose levels of 10 mg/kg. 2. When performing simultaneous whole-body (18)F-FDG PET/MR, a single dose of ferumoxytol can result in observed SUV decreases up to 53%, depending on the amount of ferumoxytol aggregates in the studied tissue. Implications for patient care Administration of a single, clinically relevant, dose of ferumoxytol can potentially result in changes in observed SUV for a prolonged period of time in the setting of simultaneous PET/MR. These potential changes should be considered in particular when administering ferumoxytol to patients with expected future PET/MR studies, as ferumoxytol-induced SUV changes might interfere with therapy assessment.
    Preview · Article · Dec 2015

  • No preview · Article · Nov 2015 · International journal of radiation oncology, biology, physics
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    ABSTRACT: Objectives: Ferumoxytol, an intravenous iron supplement, can be used in off-label mode as a contrast agent in magnetic resonance imaging. The aim of this study was to assess whether ferumoxytol can be used as a marker of inflammation in animal models of acute and chronic inflammatory kidney diseases. Material and methods: The institutional animal care committee approved this study. A total of 18 rats were examined: 6 healthy Sprague Dawley rats as a control group; 6 rats with polycystic kidney disease (PKD) as a model for chronic inflammatory disease; Thy-1, an antibody triggering glomerulonephritis, was injected in 6 rats as a model for acute inflammation. Each rat was examined directly before and 24 hours after intravenous administration of ferumoxytol at a dose of 30 mg Fe/kg body weight. T2* times of renal tissue were approximated using a multiecho sequence. Changes in relative T2* times and T2 signal intensity after ferumoxytol injection were calculated. Results: Statistically significant differences between the 3 groups were found: the T2* times of both, Thy-1 and PKD rats were statistically significant different compared with the control group (T2* time ratio after/before: Thy-1, 0.21; PKD, 0.19, control, 0.28; P = 0.002). The highest T2 signal loss in the renal cortex was observed in the Thy-1 rats (T2 signal intensity ratio after/before: Thy-1, 0.49; PKD, 0.79; control, 0.78; P = 0.0005). Conclusions: Ferumoxytol-enhanced magnetic resonance imaging allows detection and differentiation of acute and chronic inflammatory kidney disease based on different patterns of parenchymal ferumoxytol depositions. Ferumoxytol thus might help to differentiate between different types of inflammation in various kidney diseases.
    No preview · Article · Sep 2015 · Investigative radiology
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    ABSTRACT: Spatially-tailored (RF) excitation pulses in echo-planar imaging (EPI), combined with a decreased FOV in the phase-encoding direction, enable a reduction of k-space acquisition lines, which shortens the echo train length (ETL) and reduces susceptibility artifacts. The purpose of this study was to evaluate the image quality of a zoomed EPI (z-EPI) sequence in diffusion-weighted imaging (DWI) of the prostate in comparison to a conventional single-shot EPI using single-channel (c-EPI1) and multi-channel (c-EPI2) RF excitation, with and without use of an endorectal coil. 33 consecutive patients (mean age: 61 +/- 9 years; mean PSA: 8.67±6.23 ng/ml) with examinations between 10/2012 and 02/2014 were analyzed in this retrospective study. In 26 of 33 patients the initial multiparametric (mp)-MRI was performed on a whole-body 3T scanner (Magnetom Trio, Siemens, Erlangen, Germany) using an endorectal coil (c (conventional)-EPI1). Zoomed-EPI (Z-EPI) examinations of these patients and a complete mp-MRI protocol including c-EPI2 of 7 additional patients were carried out on another 3T wb MR scanner with two-channel dynamic parallel transmit capability (Magnetom Skyra with TimTX TrueShape, Siemens). For z-EPI, the one-dimensional spatially selective RF excitation pulse was replaced by a two-dimensional RF pulse. Degree of image blur and susceptibility artifacts (0=not present to 3= non-diagnostic), maximum image distortion (mm), apparent diffusion coefficient (ADC) values, as well as overall scan preference were evaluated. SNR maps were generated to compare c-EPI2 and z-EPI. Overall image quality of z-EPI was preferred by both readers in all examinations with a single exception. Susceptibility artifacts were rated significantly lower on z-EPI compared to both other methods (z-EPI vs c-EPI1: p<0.01; z-EPI vs c-EPI2: p<0.01) as well as image blur (z-EPI vs c-EPI1: p<0.01; z-EPI vs c-EPI2: p<0.01). Image distortion was not statistically significantly reduced with z-EPI (z-EPI vs c-EPI1: p=0.12; z-EPI vs c-EPI2: p=0.42). Interobserver agreement for ratings of susceptibility artifacts, image blur and overall scan preference was good. SNR was higher for z-EPI than for c-EPI1 (n=1). Z-EPI leads to significant improvements in image quality and artifacts as well as image blur reduction improving prostate DWI and enabling accurate fusion with conventional sequences. The improved fusion could lead to advantages in the field of MRI-guided biopsy suspicous lesions and performance of locally ablative procedures for prostate cancer. Copyright © 2015. Published by Elsevier GmbH.
    No preview · Article · Aug 2015 · Zeitschrift für Medizinische Physik
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    ABSTRACT: The aim of this study is the evaluation of lymph node staging by magnetic resonance imaging (MRI) within clinical routine in patients with rectal cancer. Routine MRI reports (3 T) of 65 consecutive patients with rectal cancer were retrospectively categorized in lymph node tumor positive or negative (mriN+; mriN0) and compared to the final histopathological results (pN+; pN0). Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy were calculated. The original MRI readings were then reanalyzed in order to identify the longest short-axis lymph node diameter for each patient. A receiver operating characteristic (ROC) curve was used to calculate a possible cutoff value for the short-axis lymph node diameter. Overall sensitivity was 94 %, specificity 13 %, NPV 86 %, PPV 28 %, and accuracy 34 %. The best accuracy could be calculated for a short-diameter cutoff of ≤5 mm (83 %); pN+ and pN0 groups were then significantly different (p < 0.0001). In clinical routine, lymph node assessment in patients with rectal cancer through MRI tends to overstage malignant lymphadenopathy. A ≤5-mm cutoff value for the short-axis lymph node diameter of benign nodes is able to improve the accuracy and has potential to lower the risk of overstaging.
    No preview · Article · Aug 2015 · International Journal of Colorectal Disease
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    ABSTRACT: Purpose: Breast intensity modulated radiation therapy (IMRT) reduces high-dose heart volumes but increases low-dose volumes. We prospectively assessed heart changes after 3D conformal RT (3DCRT) and IMRT for left-sided breast cancer. Heart dose was analyzed individually, 3DCRT patients were moderately exposed, and IMRT was performed only in patients with unacceptably high heart doses upon 3DCRT planning. Methods and Materials: In 49 patients (38 patients received 3DCRT; 11 patients received IMRT; and 20 patients received neoadjuvant or adjuvant chemotherapy) magnetic resonance imaging (MRI) and echocardiography were performed before and at 6, 12, and 24 months after treatment. Results: Mean heart dose for IMRT was 12.9 3.9 Gy versus 4.52.4 Gy for 3DCRT. Heart volumes receiving >40 Gy were 2.6% (3DCRT) versus 1.3% (IMRT); doses were >50 Gy only with 3DCRT. Temporary ejection fraction (EF) decrease was observed on MRI after 6 months (63%-59%, PZ.005) resolving at 24 months. Only 3 patients had pronounced largely transient changes of EF and left ventricular enddiastolic diameter (LVEDD). Mitral (M) and tricuspid (T) annular plane systolic excursion (MAPSE and TAPSE) were reduced over the whole cohort (still within normal range). After 24 months left ventricular remodeling index decreased in patients receiving chemotherapy (0.80 vs 0.70, PZ.028). Neither wall motion abnormalities nor late enhancements were found. On echocardiography, in addition to EF findings that were similar to those on MRI, global strain was unchanged over the whole cohort at 24 months after a transient decrease at 6 and 12 months. Longitudinal strain decreased in the whole cohort after 24 months in some segments, whereas it increased in others. Conclusions: Until 24 months after risk-adapted modern multimodal adjuvant therapy, only subclinical cardiac changes were observed in both 3DCRT patients with inclusion of small to moderate amounts of heart volume in RT tangents and in the patients treated with IMRT and reduced high-dose heart exposure.
    No preview · Article · Aug 2015 · International journal of radiation oncology, biology, physics
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    ABSTRACT: The aim of this review article is to define the technical prerequisites of modern state-of-the-art CT perfusion imaging in oncology at reasonable dose levels. The focus is mainly on abdominal and thoracic tumor imaging, as they pose the largest challenges with respect to attenuation and patient motion. We will show that low kV dynamic scanning in conjunction with detection technology optimized for low photon fluxes has the highest impact on reducing dose independently of other choices made in the protocol selection. We discuss, derived from relatively simple first principles, on what appropriate temporal sampling and total scan duration depend on and why optimized contrast medium injection protocols are also essential in limiting dose. Finally we will examine the possibility of simultaneously extracting standard morphological and functional information from one single 4D examination as a potential enabler for a more widespread use of dynamic contrast enhanced CT in oncology. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    Full-text · Article · Jun 2015 · European journal of radiology
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    ABSTRACT: Magnetic resonance imaging (MRI) has become an important modality for the diagnosis of intra-abdominal pathology. Hardware and pulse sequence developments have made it possible to derive not only morphologic but also functional information related to organ perfusion (dynamic contrast-enhanced MRI), oxygen saturation (blood oxygen level dependent), tissue cellularity (diffusion-weighted imaging), and tissue composition (spectroscopy). These techniques enable a more specific assessment of pathologic lesions and organ functionality. Magnetic resonance imaging has thus transitioned from a purely morphologic examination to a modality from which image-based disease biomarkers can be derived. This fits well with several emerging trends in radiology, such as the need to accurately assess response to costly treatment strategies and the need to improve lesion characterization to potentially avoid biopsy. Meanwhile, the cost-effectiveness, availability, and robustness of computed tomography (CT) ensure its place as the current workhorse for clinical imaging. Although the lower soft tissue contrast of CT relative to MRI is a long-standing limitation, other disadvantages such as ionizing radiation exposure have become a matter of public concern. Nevertheless, recent technical developments such as dual-energy CT or dynamic volume perfusion CT also provide more functional imaging beyond morphology. The aim of this article was to review and discuss the most important recent technical developments in abdominal MRI and state-of-the-art CT, with an eye toward the future, providing examples of their clinical utility for the evaluation of hepatic and renal pathologies.
    No preview · Article · Jun 2015 · Investigative radiology

  • No preview · Conference Paper · Jun 2015
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    ABSTRACT: Simultaneous data collection for positron emission tomography and magnetic resonance imaging (PET/MR) is now a reality. While the full benefits of concurrently acquiring PET and MR data and the potential added clinical value are still being evaluated, initial studies have identified several important potential pitfalls in the interpretation of fluorodeoxyglucose (FDG) PET/MRI in oncologic whole-body imaging, the majority of which being related to the errors in the attenuation maps created from the MR data. The purpose of this article was to present such pitfalls and artifacts using case examples, describe their etiology, and discuss strategies to overcome them. Using a case-based approach, we will illustrate artifacts related to (1) Inaccurate bone tissue segmentation; (2) Inaccurate air cavities segmentation; (3) Motion-induced misregistration; (4) RF coils in the PET field of view; (5) B0 field inhomogeneity; (6) B1 field inhomogeneity; (7) Metallic implants; (8) MR contrast agents.
    No preview · Article · May 2015 · Abdominal Imaging
  • D Hausmann · U Attenberger · N Rathmann · F Doyon · P Kienle · R Hofheinz · S Schönberg

    No preview · Article · Apr 2015 · RöFo - Fortschritte auf dem Gebiet der R
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    ABSTRACT: The goal of modern radiotherapy is to deliver a lethal amount of dose to tissue volumes that contain a significant amount of tumour cells while sparing surrounding unaffected or healthy tissue. Online image guided radiotherapy with stereotactic ultrasound, fiducial-based planar X-ray imaging or helical/conebeam CT has dramatically improved the precision of radiotherapy, with moving targets still posing some methodical problems regarding positioning. Therefore, requirements for precise target delineation and identification of functional body structures to be spared by high doses become more evident. The identification of areas of relatively radioresistant cells or areas of high tumor cell density is currently under development. This review outlines the state of the art of MRI integration into treatment planning and its importance in follow up and the quantification of biological effects. Finally the current state of the art of online imaging for patient positioning will be outlined and indications will be given what the potential of integrated radiotherapy/online MRI systems is. Copyright © 2015. Published by Elsevier GmbH.
    No preview · Article · Mar 2015 · Zeitschrift für Medizinische Physik
  • M Reichert · T Ai · J N Morelli · M Nittka · U Attenberger · V M Runge
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    ABSTRACT: Objective: To compare metal artefact reduction in MRI at both 3.0 T and 1.5 T using different sequence strategies. Methods: Metal implants of stainless steel screw and plate within agarose phantoms and tissue specimens as well as three patients with implants were imaged at both 1.5 T and 3.0 T, using view angle tilting (VAT), slice encoding for metal artefact correction with VAT (SEMAC-VAT) and conventional sequence. Artefact reduction in agarose phantoms was quantitatively assessed by artefact volume measurements. Blinded reads were conducted in tissue specimen and human imaging, with respect to artefact size, distortion, blurring and overall image quality. Wilcoxon and Friedman tests for multiple comparisons and intraclass correlation coefficient (ICC) for interobserver agreement were performed with a significant level of p < 0.05. Results: Compared with conventional sequences, SEMAC-VAT significantly reduced metal artefacts by 83% ± 9% for the screw and 89% ± 3% for the plate at 1.5 T; 72% ± 7% for the screw and 38% ± 13% for the plate at 3.0 T (p < 0.05). In qualitative analysis, SEMAC-VAT allowed for better visualization of tissue structures adjacent to the implants and produced better overall image quality with good interobserver agreement for both tissue specimen and human imaging (ICC = 0.80-0.99; p < 0.001). In addition, VAT also markedly reduced metal artefacts compared with conventional sequence, but was inferior to SEMAC-VAT. Conclusion: SEMAC-VAT and VAT techniques effectively reduce artefacts from metal implants relative to conventional imaging at both 1.5 T and 3.0 T. Advances in knowledge: The feasibility of metal artefact reduction with SEMAC-VAT was demonstrated at 3.0-T MR. SEMAC-VAT significantly reduced metal artefacts at both 1.5 and 3.0 T. SEMAC-VAT allowed for better visualization of the tissue structures adjacent to the metal implants. SEMAC-VAT produced consistently better image quality in both tissue specimen and human imaging.
    No preview · Article · Feb 2015
  • U.I. Attenberger · B. Wichtmann
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    ABSTRACT: Hintergrund Bereits heute ist die Magnetresonanztomographie (MRT) ein wertvolles diagnostisches Mittel zur Beurteilung der lokalen Ausdehnung des Rektumkarzinoms. Ergebnisse Die MRT hat sich dabei insbesondere im Hinblick auf die Bestimmung des Tumorabstands zur mesorektalen Faszie sowie in der Differenzierung zwischen T2- und T3-Stadien-Tumoren bewährt. Daneben eröffnen funktionelle Akquisitionstechnologien wie die diffusionsgewichtete Bildgebung (DWI) und die Perfusion neue Möglichkeiten im Sinne bildbasierter Biomarker, um Therapieansprechen und Outcome vorherzusagen. Schlussfolgerung Für einen flächendeckenden Einsatz dieser Techniken ist allerdings eine Evaluation in multizentrischen, prospektiven Studien unter standardisierten Akquisitions- und Auswertebedingungen erforderlich.
    No preview · Article · Feb 2015 · Der Onkologe
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    ABSTRACT: Objective: To compare metal artefact reduction in MRI at both 3.0 T and 1.5 T using different sequence strategies. Methods: Metal implants of stainless steel screw and plate within agarose phantoms and tissue specimens as well as three patients with implants were imaged at both 1.5 T and 3.0 T, using view angle tilting (VAT), slice encoding for metal artefact correction with VAT (SEMAC-VAT) and conventional sequence. Artefact reduction in agarose phantoms was quantitatively assessed by artefact volume measurements. Blinded reads were conducted in tissue specimen and human imaging, with respect to artefact size, distortion, blurring and overall image quality. Wilcoxon and Friedman tests for multiple comparisons and intraclass correlation coefficient (ICC) for interobserver agreement were performed with a significant level of p < 0.05. Results: Compared with conventional sequences, SEMAC-VAT significantly reduced metal artefacts by 83% ± 9% for the screw and 89% ± 3% for the plate at 1.5 T; 72% ± 7% for the screw and 38% ± 13% for the plate at 3.0 T (p < 0.05). In qualitative analysis, SEMAC-VAT allowed for better visualization of tissue structures adjacent to the implants and produced better overall image quality with good interobserver agreement for both tissue specimen and human imaging (ICC = 0.80-0.99; p < 0.001). In addition, VAT also markedly reduced metal artefacts compared with conventional sequence, but was inferior to SEMAC-VAT. Conclusion: SEMAC-VAT and VAT techniques effectively reduce artefacts from metal implants relative to conventional imaging at both 1.5 T and 3.0 T. Advances in knowledge: The feasibility of metal artefact reduction with SEMAC-VAT was demonstrated at 3.0-T MR. SEMAC-VAT significantly reduced metal artefacts at both 1.5 and 3.0 T. SEMAC-VAT allowed for better visualization of the tissue structures adjacent to the metal implants. SEMAC-VAT produced consistently better image quality in both tissue specimen and human imaging.
    No preview · Article · Jan 2015 · British Journal of Radiology
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    ABSTRACT: Objectives To evaluate the feasibility of zoomed diffusion-weighted EPI (z-EPI) in the head and neck in a healthy volunteer population and to compare to conventional single-shot EPI (c-EPI). Material and Methods Nine volunteers were included in this prospective, IRB-approved study. Examinations were performed on a 3 T-MR system equipped with a two-channel, fully-dynamic parallel transmit array. The acquired sequences consisted of a T2w-TSE, a c-EPI, and two z-EPI acquisitions. For quantitative assessment of distortion artefacts, DW images were fused with T2-TSE images. Misregistration of DW images with T2-TSE images was assessed in the cervical spine. For qualitative assessment, two readers ranked c-EPI and z-EPI sequences in terms of susceptibility artefacts, image blur, and overall imaging preference. ADC values of several anatomical regions were calculated and compared between sequences. Results Mean maximum distortion with the c-EPI was 5.9 mm ± 1.6 mm versus 2.4 mm ± 1 mm (p
    No preview · Article · Jul 2014 · European Radiology
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    ABSTRACT: Purpose The purpose of this study is two-fold. First, to evaluate, whether functional rectal MRI techniques can be analyzed in a reproducible manner by different readers and second, to assess whether different clinical and pathologic T and N stages can be differentiated by functional MRI measurements. Material and Methods 54 patients (38 men, 16 female; mean age 63.2 ± 12.2 years) with pathologically proven rectal cancer were included in this retrospective IRB-approved study. All patients were referred for a multi-parametric MRI protocol on a 3 Tesla MR-system, consisting of a high-resolution, axial T2 TSE sequence, DWI and perfusion imaging (plasma flow - PFTumor) prior to any treatment. Two experienced radiologists evaluated the MRI measurements, blinded to clinical data and outcome. Inter-reader correlation and the association of functional MRI parameters with c- and p-staging were analyzed. Results The inter-reader correlation for lymph node (ρ 0.76-0.94; p < 0.0002) and primary tumor (ρ 0.78- 0.92; p < 0.0001) apparent diffusion coefficient and plasma flow (PF) values was good to very good. PFTumor values decreased with cT stage with significant differences identified between cT2 and cT3 tumors (229 versus 107.6 ml/100 ml/min; p = 0.05). ADCTumor values did not differ significantly. No substantial discrepancies in lymph node ADCLn values or short axis diameter were found among cN1-3 stages, whereas PFLn values were distinct between cN1 versus cN2 stages (p = 0.03). In the patients without neoadjuvant RCT no statistically significant differences in the assessed functional parameters on the basis of pathologic stage were found. Conclusion This study illustrates that ADC as well as MR perfusion values can be analyzed with good interobserver agreement in patients with rectal cancer. Moreover, MR perfusion parameters may allow accurate differentiation of tumor stages. Both findings suggest that functional MRI parameters may help to discriminate T and N stages for clinical decision making.
    No preview · Article · Jul 2014 · European journal of radiology
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    ABSTRACT: Aim: To evaluate the impact of computed b = 1400 s/mm(2) (C-b1400) vs measured b = 1400 s/mm(2) (M-b1400) diffusion-weighted images (DWI) on lesion detection rate, image quality and quality of lesion demarcation using a modern 3T-MR system based on a small-field-of-view sequence (sFOV). Methods: Thirty patients (PSA: 9.5 ± 8.7 ng/mL; 68 ± 12 years) referred for magnetic resonance imaging (MRI) of the prostate were enrolled in this study. All measurements were performed on a 3T MR system. For DWI, a single-shot EPI diffusion sequence (b = 0, 100, 400, 800 s/mm²) was utilized. C-b1400 was calculated voxelwise from the ADC and diffusion images. Additionally, M-b1400 was acquired for evaluation and comparison. Lesion detection rate and maximum lesion diameters were obtained and compared. Image quality and quality of lesion demarcation were rated according to a 5-point Likert-type scale. Ratios of lesion-to-bladder as well as prostate-to-bladder signal intensity (SI) were calculated to estimate the signal-to-noise-ratio (SNR). Results: Twenty-four lesions were detected on M-b1400 images and compared to C-b1400 images. C-b1400 detected three additional cancer suspicious lesions. Overall image quality was rated significantly better and SI ratios were significantly higher on C-b1400 (2.3 ± 0.8 vs 3.1 ± 1.0, P < 0.001; 5.6 ± 1.8 vs 2.8 ± 0.9, P < 0.001). Comparison of lesion size showed no significant differences between C- and M-b1400 (P = 0.22). Conclusion: Combination of a high b-value extrapolation and sFOV may contribute to increase diagnostic accuracy of DWI without an increase of acquisition time, which may be useful to guide targeted prostate biopsies and to improve quality of multiparametric MRI (mMRI) especially under economical aspects in a private practice setting.
    Preview · Article · Jun 2014
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    ABSTRACT: Purpose To compare enhancement characteristics and image quality of two macrocyclic gadolinium chelates, gadoterate meglumine and gadobutrol, in low-dose, time-resolved MRA of the calf station. Materials and Methods 100 consecutive patients with peripheral arterial disease (stages II-IV) were retrospectively analysed. Fifty patients were included in each group - 32 men and 18 women for gadobutrol (mean age 67 years) and 34 men, 16 women for gadoterate meglumine (mean age 64 years). 0.03 mmol/kg bw of either gadobutrol or gadoterate meglumine was injected. Gadobutrol was diluted 1∶1 with normal saline (0.9% NaCl) to provide similar injection volume and bolus geometry compared to the undiluted 0.5 M dose of gadoterate meglumine. Signal-to-noise-ratio (SNR), contrast-to-noise-ratio (CNR) and image quality were analysed and compared between the two groups. Results Mean SNR ranged from 83.0±46.7 (peroneal artery) to 96.4±64.5 (anterior tibial artery) for gadobutrol, and from 37.6±13.8 (peroneal artery) to 45.3±16.4 (anterior tibial artery) for the gadoterate meglumine group (p<0.0001). CNR values ranged from 30.1±20.1 (peroneal artery) to 37.6±26.0 (anterior tibial artery) for gadobutrol and from 14.9±8.0 (peroneal artery) to 18.6±16.4 (anterior tibial artery) for gadoterate meglumine (p<0.0001). No significant difference in image quality was found except for the peroneal arteries (p = 0.006 and p = 0.04). Interreader agreement was excellent (kappa 0.87–0.93) Conclusion The significantly better enhancement as assessed by SNR and CNR provided by gadobutrol compared to gadoterate meglumine does not translate into substantial differences in image quality in an equimolar, low-dose, time-resolved MRA protocol of the calves.
    Preview · Article · Jun 2014 · PLoS ONE
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    ABSTRACT: To evaluate the diagnostic accuracy of a nonenhanced electrocardiograph-gated quiescent-interval single shot MR-angiography (QISS-MRA) at 3 Tesla with contrast-enhanced MRA (CE-MRA) and digital subtraction angiography (DSA) serving as reference standard. Following institutional review board approval, 16 consecutive patients with peripheral arterial disease underwent a combined peripheral MRA protocol consisting of a large field-of-view QISS-MRA, continuous table movement MRA, and an additional time-resolved MRA of the calves. DSA correlation was available in eight patients. Image quality and degree of stenosis was assessed. Sensitivity and specificity of QISS-MRA was evaluated with CE-MRA and DSA serving as the standards of reference and compared using the Fisher exact test. With the exception of the calf station, image quality with QISS-MRA was rated statistically significantly less than that of CE-MRA (P < 0.05, P = 0.17, and P = 0.6, respectively). A greater percentage of segments were not accessible with QISS-MRA (19.5-20.1%) in comparison to CE-MRA (10.9%). Relative to DSA, sensitivity for QISS-MRA was high (100% versus 91.2% for CE-MRA, P = 0.24) in the evaluated segments; however, specificity (76.5%) was substantially less than that of CE-MRA (94.6%, P = 0.003). Overall image quality and specificity of QISS-MRA at 3T are diminished relative to CE-MRA. However, when image quality is adequate, QISS-MRA has high sensitivity and, thus, has potential use in patients with contraindications to gadolinium. J. Magn. Reson. Imaging 2013. © 2013 Wiley Periodicals, Inc.
    No preview · Article · Jun 2014 · Journal of Magnetic Resonance Imaging

Publication Stats

1k Citations
305.33 Total Impact Points

Institutions

  • 2010-2015
    • Universität Mannheim
      Mannheim, Baden-Württemberg, Germany
  • 2009-2015
    • Universität Heidelberg
      • • Department of Nuclear Medicine
      • • Institute of Clinical Radiology
      Heidelburg, Baden-Württemberg, Germany
  • 2004-2009
    • Ludwig-Maximilians-University of Munich
      • Department of Clinical Radiology
      München, Bavaria, Germany