ALBERT

Description: Objective   Hepatic signal recovery, rather than reduction, in ferucarbotran-enhanced magnetic resonance imaging (MRI) is a potential diagnostic marker of liver damage. We investigated hepatic signal recovery in rats with gadolinium chloride (GdCl 3 )-induced Kupffer cell (KC) damage. Materials and methods   Twelve rats received 8 μmol iron/kg of ferucarbotran 1 day after 0–7.5 mg/kg GdCl 3 injection (experiment A). Another 12 rats received ferucarbotran followed by GdCl 3 injection 6 h later (experiment B). In each experiment, three rats without GdCl 3 (“no injury group”) served as control. Another six rats received GdCl 3 alone without ferucarbotran. Hepatic signals were assessed on T 2 * -weighted images for up to 29 days. Iron deposits were histologically examined on day 29. Results   Hepatic signal recovery was delayed in a GdCl 3 dose-dependent manner in experiment A. Gadolinium chloride alone reduced hepatic signal 15 % during this experiment. Hepatic signal recovery was delayed only in rats that received 7.5 mg/kg GdCl 3 in experiment B. Hepatic signals negatively correlated with iron deposits in KCs and hepatocytes. Conclusion   Hepatic signal recovery on ferucarbotran-enhanced MRI was delayed in the context of GdCl 3 -induced KC damage due to increased hepatic iron deposits. Hepatic signal recovery may be used as a clinical marker of KC damage in liver disorders, including radiation-induced hepatitis. Content Type Journal Article Category Research Article Pages 1-12 DOI 10.1007/s10334-012-0354-3 Authors Toshihiro Furuta, Division of Functional Imaging, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Japan Masayuki Yamaguchi, Division of Functional Imaging, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Japan Ryutaro Nakagami, Division of Functional Imaging, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Japan Masaaki Akahane, Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan Manabu Minami, Department of Radiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan Kuni Ohtomo, Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan Noriyuki Moriyama, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan Hirofumi Fujii, Division of Functional Imaging, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Japan Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243

Description: Object   To assess the feasibility of magnetization transfer (MT) imaging of the bowel wall in patients with Crohn’s disease (CD), and to evaluate its utility for the detection of intestinal fibrosis. Materials and methods   In this prospective study, 31 patients (age 39.0 ± 13.2 years) with CD were examined in a 1.5T MR scanner. To establish a standard of reference, two independent readers classified the patients in different disease states using standard MR enterography, available clinical data and histological findings. In addition to the standard protocol, a 2D gradient-echo sequence (TR/TE 32 ms/2.17 ms; flip angle 25°) with/without 1,100 Hz off-resonance prepulse was applied. MT ratios (MTR) of the small bowel wall were computed off-line on a pixel-by-pixel basis. Results   The MT sequences acquired images of sufficient quality and spatial resolution for the evaluation of the small bowel wall without detrimental motion artefacts. In normal bowel wall segments, an intermediate MTR of 25.4 ± 3.4 % was measured. The MTR was significantly increased in bowel wall segments with fibrotic scarring (35.3 ± 4.0 %, p  〈 0.0001). In segments with acute inflammation, the mean MTR was slightly smaller (22.9 ± 2.2 %). Conclusion   MT imaging of the small bowel wall is feasible in humans with sufficient image quality and may help with the identification of fibrotic scarring in patients with CD. Content Type Journal Article Category Research Article Pages 1-11 DOI 10.1007/s10334-012-0355-2 Authors Shila Pazahr, Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistr. 100, 8091 Zurich, Switzerland Iris Blume, Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistr. 100, 8091 Zurich, Switzerland Pascal Frei, Department of Gastroenterology, University Hospital Zurich, Zurich, Switzerland Natalie Chuck, Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistr. 100, 8091 Zurich, Switzerland Daniel Nanz, Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistr. 100, 8091 Zurich, Switzerland Gerhard Rogler, Department of Gastroenterology, University Hospital Zurich, Zurich, Switzerland Michael Patak, Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistr. 100, 8091 Zurich, Switzerland Andreas Boss, Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistr. 100, 8091 Zurich, Switzerland Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243

Description: Object   The sequence combining DQF (double quantum filtering) with magnetisation transfer (DQF-MT) was tested as an alternative to the DQF sequence for characterising tendon and muscle by MR imaging. Materials and methods   DQF-MT images of tendon–muscle phantoms were obtained at 4.7 T using ultra-short time to echo (UTE) methods in order to alleviate the loss of SNR due to the short T 2 of the tissues. Two different sampling schemes of the k -space, Cartesian or radial, were employed. In vivo images of the human ankle on a clinical 1.5 T scanner are also presented. Parameters providing optimal tendon signal as well as optimal contrast between this tissue and muscle were determined. Results   Two sets of parameters resulting in different contrasts between the tissues were found. For the first set (short creation time τ = 10 μs and magnetisation exchange time t LM  = 100 ms), DQF-MT signals in muscle and tendon were detected, with that of the tendon being the larger one. For the second set (long creation time τ = 750 μs and magnetisation exchange time 10 μs 〈  t LM  〈 100 ms), the DQF-MT signal was detected only in the tendon, and the decay of the double quantum coherence was slower than that observed for the first one, which allowed us to acquire DQF-MT MR images on a clinical 1.5 T MR scanner with minimal software interventions. In favourable conditions, the DQF-MT signal in the tendon could represent up to 10 % of the single-quantum signal. Conclusion   Dipolar interaction within macromolecules such as collagen and myosin is at the origin of the DQF-MT signal observed in the first parameter set. This should enable the detection of muscle fibrosis. Content Type Journal Article Category Research Article Pages 1-12 DOI 10.1007/s10334-012-0346-3 Authors Slawomir Kusmia, IR4M UMR8081 CNRS Univ Paris-Sud, CIERM-Hôp Bicetre, 94275 Le Kremlin Bicetre, France Uzi Eliav, School of Chemistry, Tel Aviv University, Tel Aviv, Israel Gil Navon, School of Chemistry, Tel Aviv University, Tel Aviv, Israel Geneviève Guillot, IR4M UMR8081 Univ Paris-Sud, Bât 220, 91405 Orsay, France Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243

Description: Object   To develop and evaluate a model for describing the S1 (S + ) and S2 (S − ) phase in the presence of off-resonance frequency fluctuations, and to evaluate the performance of a novel interleaved navigator echo scheme. Materials and methods   Using the extended phase graph model, a linear phase term was added to the evolution of transverse states. An approximation for the total S2 phase was derived with one fit parameter τ l , which serves as an effective lifetime of the S2 signal. The model was evaluated using synthetic and in vivo phase evolution data. In addition, a novel interleaved phase correction scheme for the nb-SSFP sequence was applied to BOLD-fMRI data, and the number of activated voxels before and after phase correction was determined. Results   The phases of S1 and S2 signals are significantly different from each other. The proposed nb-SSFP phase model provided a good description of the measured phase evolution data, and the approximate model for the S2 phase provided both at good fit to the data, as well as an effective lifetime of the S2 signal. In some subjects the phase contribution from older pathways was underestimated. In the BOLD-fMRI data, a twofold increase of the number of activated voxels for the S2 signal was observed, compared to no correction and a conventional navigator echo method. Conclusion   The different phase evolution of S1 and S2 signals can be qualitatively described by the proposed model, and detrimental phase history effects are significant at 7 Tesla when not appropriately corrected. Content Type Journal Article Category Research Article Pages 1-11 DOI 10.1007/s10334-012-0343-6 Authors Pål Erik Goa, MI-lab, Department of Medical Imaging, St. Olavs University Hospital, Trondheim, Norway Benedikt Andreas Poser, Erwin L. Hahn Institute of Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany Markus Barth, Erwin L. Hahn Institute of Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243

Description: Object   The relative amounts of choline (Cho), phosphocholine (PC), and glycerophosphocholine (GPC) may be sensitive indicators of breast cancer and the degree of malignancy. Here we implement some simple modifications to a previously developed 1 H NMR analysis of fine-needle-aspirate (FNA) biopsies designed to yield sufficient spectral resolution of Cho, PC, and GPC for usable relative quantitation of these metabolites. Materials and methods   FNA biopsies of eighteen breast lesions were examined using our modified procedure for direct 1 H NMR at 400 MHz. Resonances of choline metabolites and potential interferences were fit using the computer program NUTS. Results   Quantitation of PC, GPC, and Cho relative to each other and to (phospho)creatine was obtained for eleven confirmed cases of infiltrating ductal carcinoma. Reliable results could not be obtained for the remaining cases primarily due to interference from lidocaine anesthetic. Conclusion   Some simple modifications of a previously developed 1 H NMR analysis of FNAs yielded sufficient spectral resolution of Cho, PC, and GPC to permit usable relative quantitation at 400 MHz. In 9 of the 11 quantified cases the sum of GPC and Cho exceeded 42 % of the total choline-metabolite peak area. Content Type Journal Article Category Research Article Pages 1-7 DOI 10.1007/s10334-012-0349-0 Authors John M. Pearce, Center for Imaging Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0583, USA Mary C. Mahoney, Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA Jing-Huei Lee, Center for Imaging Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0583, USA Wen-Jang Chu, Center for Imaging Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0583, USA Kim M. Cecil, Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA Stephen M. Strakowski, Center for Imaging Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0583, USA Richard A. Komoroski, Center for Imaging Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0583, USA Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243

Description: Object   By measuring the apparent diffusion coefficient (ADC) of liver parenchyma and focal hepatic lesions (FHL) we proposed to investigate the utility of ADC in the differential diagnosis of hepatic disease and to determine the influence of region of interest (ROI) characteristics in those measurements. Materials and methods   Ninety-three patients with at least one supracentimetric FHL, or parenchymal abnormality, were retrospectively evaluated. Diagnosis was based on histopathologic data or, alternatively, on a combination of consensus between imaging methods and 24 months of follow-up. Ninety lesions were evaluated with respiratory-triggered diffusion-weighted imaging ( b values: 50 and 700 s/mm 2 ): 14 hepatocellular carcinomas, 18 metastases, 10 focal nodular hyperplasias, four adenomas, 30 hemangiomas and 14 cysts. ADC of hepatic parenchyma was measured by placing ROIs in four different segments, and in FHLs by using three circular 1 cm 2 ROIs and one ROI encompassing the full lesion. Data was statistically analyzed ( p  〈 0.05 considered significant), and a receiver operating characteristic curve was assessed to evaluate the accuracy for the diagnosis of malignancy. Results   Our measurements showed that parenchyma ADC was significantly higher in segment II and that ADCs of malignant lesions were significantly lower than those of benign lesions ( p  〈 0.001). There was significant overlap between benign solid lesions and malignant lesions and the area under the curve for malignancy was 0.939 (sensitivity 89.7 %, specificity 90.6 %), using a cutoff of 1.43 × 10 −3 mm 2 /s. No significant difference was found between ROIs of different characteristics. Conclusion   ADC measurements can help to characterize FHLs and differentiate normal from pathological parenchyma. Any ROI above 1 cm 2 can provide accurate ADC measurements in homogenous lesions. Content Type Journal Article Category Research Article Pages 1-10 DOI 10.1007/s10334-012-0348-1 Authors João Pedro Filipe, Universitary Clinic of Radiology, Coimbra University Hospitals, Coimbra, Portugal Luís Curvo-Semedo, Universitary Clinic of Radiology, Coimbra University Hospitals, Coimbra, Portugal João Casalta-Lopes, Biophysics Unit, IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal Maria Cristina Marques, Universitary Clinic of Radiology, Coimbra University Hospitals, Coimbra, Portugal Filipe Caseiro-Alves, Universitary Clinic of Radiology, Coimbra University Hospitals, Coimbra, Portugal Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243

Description:    The objective of this study was to develop an automatic image registration technique capable of compensating for kidney motion in renal perfusion MRI, to assess the effect of renal artery stenosis on the kidney parenchyma. Materials and methods   Images from 20 patients scheduled for a renal perfusion study were acquired using a 1.5 T scanner. A free-breathing 3D-FSPGR sequence was used to acquire coronal views encompassing both kidneys following the infusion of Gd-BOPTA. A two-step registration algorithm was developed, including a preliminary registration minimising the quadratic difference and a fine registration maximising the mutual information (MI) between consecutive image frames. The starting point for the MI-based registration procedure was provided by an adaptive predictor that was able to predict kidney motion using a respiratory movement model. The algorithm was validated against manual registration performed by an expert user. Results   The mean distance between the automatically and manually defined contours was 2.95 ± 0.81 mm, which was not significantly different from the interobserver variability of the manual registration procedure (2.86 ± 0.80 mm, P  = 0.80). The perfusion indices evaluated on the manually and automatically extracted perfusion curves were not significantly different. Conclusions   The developed method is able to automatically compensate for kidney motion in perfusion studies, which prevents the need for time-consuming manual image registration. Content Type Journal Article Category Research Article Pages 1-11 DOI 10.1007/s10334-012-0337-4 Authors Vincenzo Positano, Fondazione CNR Regione Toscana “G. Monasterio”, Via Moruzzi, 1, 56124 Pisa, Italy Ilaria Bernardeschi, Fondazione CNR Regione Toscana “G. Monasterio”, Via Moruzzi, 1, 56124 Pisa, Italy Virna Zampa, Department of Diagnostic and Interventional Radiology, University of Pisa, Pisa, Italy Martina Marinelli, Institute of Clinical Physiology, CNR, Pisa, Italy Luigi Landini, Fondazione CNR Regione Toscana “G. Monasterio”, Via Moruzzi, 1, 56124 Pisa, Italy Maria Filomena Santarelli, Institute of Clinical Physiology, CNR, Pisa, Italy Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243

Description: Purpose   Integrated whole-body PET/MRI tomographs have become available. PET/MR imaging has the potential to supplement, or even replace combined PET/CT imaging in selected clinical indications. However, this is true only if methodological pitfalls and image artifacts arising from novel MR-based attenuation correction (MR-AC) are fully understood. Results   Here we present PET/MR image artifacts following routine MR-AC, as most frequently observed in clinical operations of an integrated whole-body PET/MRI system. Conclusion   A clinical adoption of integrated PET/MRI should entail the joint image display and interpretation of MR data, MR-based attenuation maps and uncorrected plus attenuation-corrected PET images in order to recognize potential pitfalls from MR-AC and to ensure clinically accurate image interpretation. Content Type Journal Article Category Short Communication Pages 1-9 DOI 10.1007/s10334-012-0345-4 Authors Sune H. Keller, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark Søren Holm, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark Adam E. Hansen, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark Bernhard Sattler, Department of Nuclear Medicine, University Hospital Leipzig, Leipzig, Germany Flemming Andersen, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark Thomas L. Klausen, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark Liselotte Højgaard, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark Andreas Kjær, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark Thomas Beyer, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243

Description:    Magnetic resonance imaging (MRI) is the examination method of choice for the diagnosis of a variety of diseases. MRI allows us to obtain not only anatomical information but also identification of physiological and functional parameters such as networks in the brain and tumor cellularity, which plays an increasing role in oncologic imaging, as well as blood flow and tissue perfusion. However, in many cases such as in epilepsy, degenerative neurological diseases and oncological processes, additional metabolic and molecular information obtained by PET can provide essential complementary information for better diagnosis. The combined information obtained from MRI and PET acquired in a single imaging session allows a more accurate localization of pathological findings and better assessment of the underlying physiopathology, thus providing a more powerful diagnostic tool. Two hundred and twenty-one patients were scanned from April 2011 to January 2012 on a Philips Ingenuity TF PET/MRI system. The purpose of this review article is to provide an overview of the techniques used for the optimization of different protocols performed in our hospital by specialists in the following fields: neuroradiology, head and neck, breast, and prostate imaging. This paper also discusses the different problems encountered, such as the length of studies, motion artifacts, and accuracy of image fusion including physical and technical aspects, and the proposed solutions. Content Type Journal Article Category Review Article Pages 1-13 DOI 10.1007/s10334-012-0340-9 Authors Maria-Isabel Vargas, Neuroradiology, Geneva University Hospitals, 4 Gabrielle-Perret-Gentil, 1211 Genève, Switzerland Minerva Becker, Radiology, Geneva University Hospitals, 4 Gabrielle-Perret-Gentil, 1211 Genève, Switzerland Valentina Garibotto, Nuclear Medicine, Geneva University Hospitals, 4 Gabrielle-Perret-Gentil, 1211 Genève, Switzerland Susanne Heinzer, Philips AG Healthcare, Allmendstrasse 140, 8027 Zurich, Switzerland Pierre Loubeyre, Radiology, Geneva University Hospitals, 4 Gabrielle-Perret-Gentil, 1211 Genève, Switzerland Joanna Gariani, Radiology, Geneva University Hospitals, 4 Gabrielle-Perret-Gentil, 1211 Genève, Switzerland Karl Lovblad, Neuroradiology, Geneva University Hospitals, 4 Gabrielle-Perret-Gentil, 1211 Genève, Switzerland Jean-Paul Vallée, Radiology, Geneva University Hospitals, 4 Gabrielle-Perret-Gentil, 1211 Genève, Switzerland Osman Ratib, Nuclear Medicine, Geneva University Hospitals, 4 Gabrielle-Perret-Gentil, 1211 Genève, Switzerland Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243

Description: ESMRMB 2012, 29th Annual Scientific Meeting, Lisbon, Portugal, 4-6 October: EPOS TM Poster / Paper Poster / Clinical Review Poster / Software Exhibits Content Type Journal Article Pages 339-628 DOI 10.1007/s10334-012-0324-9 Journal Magnetic Resonance Materials in Physics, Biology and Medicine Online ISSN 1352-8661 Print ISSN 0968-5243 Journal Volume Volume 25 Journal Issue Volume 25, Supplement 1