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Yaras YS, Yildirim DK, Herzka DA, Rogers T, Campbell-Washburn AE, Lederman RJ, Degertekin FL, Kocaturk O. Real-time device tracking under MRI using an acousto-optic active marker. Magn Reson Med 2020; 85:2904-2914. [PMID: 33347642 DOI: 10.1002/mrm.28625] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/30/2020] [Accepted: 11/09/2020] [Indexed: 12/31/2022]
Abstract
PURPOSE This work aims to demonstrate the use of an "active" acousto-optic marker with enhanced visibility and reduced radiofrequency (RF) -induced heating for interventional MRI. METHODS The acousto-optic marker was fabricated using bulk piezoelectric crystal and π-phase shifted fiber Bragg grating (FBGs) and coupled to a distal receiver coil on an 8F catheter. The received MR signal is transmitted over an optical fiber to mitigate RF-induced heating. A photodetector converts the optical signal into electrical signal, which is used as the input signal to the MRI receiver plug. Acousto-optic markers were characterized in phantom studies. RF-induced heating risk was evaluated according to ASTM 2182 standard. In vivo real-time tracking capability was tested in an animal model under a 0.55T scanner. RESULTS Signal-to-noise ratio (SNR) levels suitable for real-time tracking were obtained by using high sensitivity FBG and piezoelectric transducer with resonance matched to Larmor frequency. Single and multiple marker coils integrated to 8F catheters were readout for position and orientation tracking by a single acousto-optic sensor. RF-induced heating was significantly reduced compared to a coax cable connected reference marker. Real-time distal tip tracking of an active device was demonstrated in an animal model with a standard real-time cardiac MR sequence. CONCLUSION Acousto-optic markers provide sufficient SNR with a simple structure for real-time device tracking. RF-induced heating is significantly reduced compared to conventional active markers. Also, multiple RF receiver coils connected on an acousto-optic modulator can be used on a single catheter for determining catheter orientation and shape.
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Affiliation(s)
- Yusuf S Yaras
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Micromachined Sensors and Transducers Group, Atlanta, Georgia, USA
| | - Dursun Korel Yildirim
- National Institutes of Health, National Heart Lung and Blood Institute, Bethesda, Maryland, USA
| | - Daniel A Herzka
- National Institutes of Health, National Heart Lung and Blood Institute, Bethesda, Maryland, USA
| | - Toby Rogers
- National Institutes of Health, National Heart Lung and Blood Institute, Bethesda, Maryland, USA
| | | | - Robert J Lederman
- National Institutes of Health, National Heart Lung and Blood Institute, Bethesda, Maryland, USA
| | - F Levent Degertekin
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Micromachined Sensors and Transducers Group, Atlanta, Georgia, USA
| | - Ozgur Kocaturk
- Institute of Biomedical Engineering, Bogazici University, Kandilli Kampus, Istanbul, Turkey
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Abstract
Magnetic resonance (MR) imaging relies on a strong static magnetic field in conjunction with careful orchestration of pulsed linear gradient magnetic fields and radiofrequency magnetic fields in order to generate images. The interaction of these fields with patients as well as materials with magnetic or conducting properties can be a source of risk in the MR environment. This article provides a basic review of the physical underpinnings of the primary risks in MR imaging to foster development of intuition with respect to both patient and risk management in the MR environment.
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Affiliation(s)
- Roger Jason Stafford
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Unit 1472, Houston, TX 77030, USA.
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Hearing Thresholds Changes after MRI 1.5T of Head and Neck. Radiol Res Pract 2019; 2019:8756579. [PMID: 31316833 PMCID: PMC6601493 DOI: 10.1155/2019/8756579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 04/24/2019] [Accepted: 05/26/2019] [Indexed: 12/20/2022] Open
Abstract
Introduction Exposure to high intensity noise produced by MRI is a cause for concern. This study was conducted to determine the temporary and permanent effects of exposure to noise created by performing MRI on the hearing threshold of the subjects using conventional and extended high frequency audiometry. Methods This semiexperimental study was performed on 35 patients referred to Shahid Rahnemoun Hospital for head and neck MRI due to different clinical conditions. The hearing threshold of patients was measured before, immediately after, and 24 hours after performing 1.5 Tesla MRI using conventional and extended high frequency audiometry. SPSS version 18 was used to compare the mean hearing thresholds before and after MRI using paired T test and repeated measures analysis. Results Comparison of auditory thresholds in conventional and extended high frequencies before and immediately after MRI showed a significant shift at 4 KHz (P = 0.008 and P = 0.08 for right and left ears), 6 KHz (P = 0.03 and P = 0.01 for right and left ears), and 14 KHz (P =0.03 and P = 0.31 for right and left ears). However, there was no significant difference between audiometric thresholds before and 24 hours after MRI. Conclusion Noise due to 1.5 Tesla MRI can only cause transient threshold shift.
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Jin C, Li H, Li X, Wang M, Liu C, Guo J, Yang J. Temporary Hearing Threshold Shift in Healthy Volunteers with Hearing Protection Caused by Acoustic Noise Exposure during 3-T Multisequence MR Neuroimaging. Radiology 2018; 286:602-608. [PMID: 28813235 DOI: 10.1148/radiol.2017161622] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Chao Jin
- From the Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Road, Xi’an 710061, PR China (C.J., H.L., X.L., M.W., C.L., J.G., J.Y.); and Department of Biomedical Engineering, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, PR China (X.L., J.Y.)
| | - Huan Li
- From the Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Road, Xi’an 710061, PR China (C.J., H.L., X.L., M.W., C.L., J.G., J.Y.); and Department of Biomedical Engineering, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, PR China (X.L., J.Y.)
| | - Xianjun Li
- From the Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Road, Xi’an 710061, PR China (C.J., H.L., X.L., M.W., C.L., J.G., J.Y.); and Department of Biomedical Engineering, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, PR China (X.L., J.Y.)
| | - Miaomiao Wang
- From the Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Road, Xi’an 710061, PR China (C.J., H.L., X.L., M.W., C.L., J.G., J.Y.); and Department of Biomedical Engineering, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, PR China (X.L., J.Y.)
| | - Congcong Liu
- From the Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Road, Xi’an 710061, PR China (C.J., H.L., X.L., M.W., C.L., J.G., J.Y.); and Department of Biomedical Engineering, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, PR China (X.L., J.Y.)
| | - Jianxin Guo
- From the Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Road, Xi’an 710061, PR China (C.J., H.L., X.L., M.W., C.L., J.G., J.Y.); and Department of Biomedical Engineering, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, PR China (X.L., J.Y.)
| | - Jian Yang
- From the Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Road, Xi’an 710061, PR China (C.J., H.L., X.L., M.W., C.L., J.G., J.Y.); and Department of Biomedical Engineering, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, PR China (X.L., J.Y.)
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Corcuera-Solano I, Doshi A, Pawha PS, Gui D, Gaddipati A, Tanenbaum L. Quiet PROPELLER MRI techniques match the quality of conventional PROPELLER brain imaging techniques. AJNR Am J Neuroradiol 2015; 36:1124-7. [PMID: 25678482 DOI: 10.3174/ajnr.a4235] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 12/05/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Switching of magnetic field gradients is the primary source of acoustic noise in MR imaging. Sound pressure levels can run as high as 120 dB, capable of producing physical discomfort and at least temporary hearing loss, mandating hearing protection. New technology has made quieter techniques feasible, which range from as low as 80 dB to nearly silent. The purpose of this study was to evaluate the image quality of new commercially available quiet T2 and quiet FLAIR fast spin-echo PROPELLER acquisitions in comparison with equivalent conventional PROPELLER techniques in current day-to-day practice in imaging of the brain. MATERIALS AND METHODS Thirty-four consecutive patients were prospectively scanned with quiet T2 and quiet T2 FLAIR PROPELLER, in addition to spatial resolution-matched conventional T2 and T2 FLAIR PROPELLER imaging sequences on a clinical 1.5T MR imaging scanner. Measurement of sound pressure levels and qualitative evaluation of relative image quality was performed. RESULTS Quiet T2 and quiet T2 FLAIR were comparable in image quality with conventional acquisitions, with sound levels of approximately 75 dB, a reduction in average sound pressure levels of up to 28.5 dB, with no significant trade-offs aside from longer scan times. CONCLUSIONS Quiet FSE provides equivalent image quality at comfortable sound pressure levels at the cost of slightly longer scan times. The significant reduction in potentially injurious noise is particularly important in vulnerable populations such as children, the elderly, and the debilitated. Quiet techniques should be considered in these special situations for routine use in clinical practice.
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Affiliation(s)
- I Corcuera-Solano
- From the Neuroradiology Section, Department of Radiology (I.C.-S., A.D., P.S.P., L.T.), Icahn School of Medicine at Mount Sinai Hospital, Radiology, New York, New York
| | - A Doshi
- From the Neuroradiology Section, Department of Radiology (I.C.-S., A.D., P.S.P., L.T.), Icahn School of Medicine at Mount Sinai Hospital, Radiology, New York, New York
| | - P S Pawha
- From the Neuroradiology Section, Department of Radiology (I.C.-S., A.D., P.S.P., L.T.), Icahn School of Medicine at Mount Sinai Hospital, Radiology, New York, New York
| | - D Gui
- GE Healthcare (D.G., A.G.), Milwaukee, Wisconsin
| | - A Gaddipati
- GE Healthcare (D.G., A.G.), Milwaukee, Wisconsin
| | - L Tanenbaum
- From the Neuroradiology Section, Department of Radiology (I.C.-S., A.D., P.S.P., L.T.), Icahn School of Medicine at Mount Sinai Hospital, Radiology, New York, New York
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Sensorineural hearing loss after magnetic resonance imaging. Case Rep Radiol 2013; 2013:510258. [PMID: 23844303 PMCID: PMC3703385 DOI: 10.1155/2013/510258] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/05/2013] [Indexed: 11/18/2022] Open
Abstract
Magnetic resonance imaging (MRI) devices produce noise, which may affect patient's or operators' hearing. Some cases of hearing impairment after MRI procedure have been reported with different patterns (temporary or permanent, unilateral or bilateral, with or without other symptoms like tinnitus). In this report, a case of bilateral sensorineural hearing loss in an otherwise healthy patient underwent brain MRI was described. The patient's hearing loss was accompanied with tinnitus and was not improved after 3 months of followup.
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Labadie C, Hetzer S, Schulz J, Mildner T, Aubert-Frécon M, Möller HE. Center-out echo-planar spectroscopic imaging with correction of gradient-echo phase and time shifts. Magn Reson Med 2012; 70:16-24. [PMID: 22847848 DOI: 10.1002/mrm.24428] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 06/29/2012] [Accepted: 07/02/2012] [Indexed: 01/04/2023]
Abstract
A procedure to prevent the formation of image and spectral Nyquist ghosts in echo-planar spectroscopic imaging is introduced. It is based on a novel Cartesian center-out echo-planar spectroscopic imaging trajectory, referred to as EPSICO, and combined with a correction of the gradient-echo phase and time shifts. Processing of homogenous sets of forward and reflected echoes is no longer necessary, resulting in an optimized spectral width. The proposed center-out trajectory passively prevents the formation of Nyquist ghosts by privileging the acquisition of the center k-space line with forward echoes at the beginning of an echo-planar spectroscopic imaging dwell time and by ensuring that all k-space lines and their respective complex conjugates are acquired at equal time intervals. With the proposed procedure, concentrations of N-acetyl aspartate, creatine, choline, glutamate, and myo-inositol were reliably determined in human white matter at 3 T.
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Affiliation(s)
- Christian Labadie
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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Abstract
Medical imaging in interventional oncology is used differently than in diagnostic radiology and prioritizes different imaging features. Whereas diagnostic imaging prioritizes the highest-quality imaging, interventional imaging prioritizes real-time imaging with lower radiation dose in addition to high-quality imaging. In general, medical imaging plays five key roles in image-guided therapy, and interventional oncology, in particular. These roles are (a) preprocedure planning, (b) intraprocedural targeting, (c) intraprocedural monitoring, (d) intraprocedural control, and (e) postprocedure assessment. Although many of these roles are still relatively basic in interventional oncology, as research and development in medical imaging focuses on interventional needs, it is likely that the role of medical imaging in intervention will become even more integral and more widely applied. In this review, the current status of medical imaging for intervention in oncology will be described and directions for future development will be examined.
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Affiliation(s)
- Stephen B Solomon
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10021, USA.
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László J, Gyires K. 3 T homogeneous static magnetic field of a clinical MR significantly inhibits pain in mice. Life Sci 2008; 84:12-7. [PMID: 19000698 DOI: 10.1016/j.lfs.2008.10.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Revised: 10/01/2008] [Accepted: 10/04/2008] [Indexed: 10/21/2022]
Abstract
AIMS In recent years nuclear magnetic resonance (MR) systems have proliferated worldwide. This imaging/spectroscopy technique utilizes a strong homogeneous static magnetic field, much smaller time-varying gradient magnetic fields, and radiofrequency radiation. Many studies addressed the question of potential adverse side effects induced by MR, but less attention has been paid to its potential beneficial, therapeutical effects. The present study shows that whole body exposure of mice to the 3 T homogeneous static magnetic field of a clinical MR resulted in a statistically significant antinociceptive activity. MAIN METHODS Antinociceptive activity was studied in the writhing test, where pain was elicited by the intraperitoneal injection of 0.6% acetic acid in the mouse. No imaging sequence of the MR was used during the experiments. Mice could freely move in their cage without any restraint. KEY FINDINGS An antinociceptive activity of 68+/-2% (p<0.001, n=18) was found. Subcutaneous injection of naloxone (0.2 mg/kg) in the mice reversed the magnetic field-induced antinociceptive activity. The effect of noise, vibration and lighting stimuli could be neglected. Although motion-induced effects generated in the body of the mice could not be completely excluded, their influence on pain perception was estimated to be below threshold. SIGNIFICANCE MR's static magnetic field should be regarded as a potential therapeutical tool.
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Affiliation(s)
- János László
- Section for Mathematics, Hungarian Academy of Sciences, Budapest, Nádor u. 7, 1051-Hungary.
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Bock M, Wacker FK. MR-guided intravascular interventions: techniques and applications. J Magn Reson Imaging 2008; 27:326-38. [PMID: 18219686 DOI: 10.1002/jmri.21271] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Magnetic resonance imaging (MRI) offers several advantages over other imaging modalities that make it an attractive imaging tool for diagnostic and therapeutic procedures. This tremendous potential of MRI has provided the rationale for increased attention toward MR-guided endovascular interventions. MR guidance has been used recently to navigate endovascular catheters and deliver stents, vena cava filters, embolization materials, and septum closure devices. However, its potential goes beyond just copying existing procedures toward the development of new minimally invasive techniques that cannot be performed with conventional guiding techniques. Because of technical limitations and safety issues associated with some of the currently available devices, a limited number of clinical studies have been performed so far. The overall success for this developing field requires considerable interdisciplinary research within both the interventional and the MR community. Only through a combined effort can this complex technology find its way into clinical practice. This review discusses the hardware and software improvements that have helped to advance endovascular interventions under MR imaging guidance from a pure research tool to become a clinical reality. In addition, technical and safety issues specific to endovascular MR image guidance will be described and practical applications will be shown that take advantage of the benefits of MR for endovascular interventions.
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Affiliation(s)
- Michael Bock
- Deutsches Krebsforschungszentrum, Department of Medical Physics in Radiology (E020), Heidelberg, Germany
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Hushek SG, Russell L, Moser RF, Hoerter NM, Moriarty TM, Shields CB. Safety protocols for interventional MRI. Acad Radiol 2005; 12:1143-8. [PMID: 16112514 DOI: 10.1016/j.acra.2005.05.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Revised: 05/30/2005] [Accepted: 03/15/2005] [Indexed: 11/25/2022]
Abstract
RATIONALE AND OBJECTIVES To review magnetic resonance safety protocols and supplement them for interventional applications. MATERIALS AND METHODS The American College of Radiology White Papers on MR Safety are summarized. Elements relevant to interventional MR procedures are emphasized. Additional policies and procedures specifically for interventional MR applications covering safety, training, and MR compatibility are proposed. RESULTS A comprehensive operational policy for an interventional MR department is proposed. The policies and procedures helped our department perform over 400 surgeries and maintain a perfect safety record for 5 years. CONCLUSION Interventional MR departments can operate safely but require policies and procedures beyond those required for diagnostic MR departments.
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Moelker A, Maas RAJJ, Pattynama PMT. Verbal communication in MR environments: effect of MR system acoustic noise on speech understanding. Radiology 2004; 232:107-13. [PMID: 15220495 DOI: 10.1148/radiol.2321030955] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To assess the masking effect of magnetic resonance (MR)-related acoustic noise and the effect of passive hearing protection on speech understanding. MATERIALS AND METHODS Acoustic recordings were made at 1.5 T at patient and operator (interventionalist in the MR suite) locations for relevant pulse sequences. In an audiologic laboratory, speech-to-noise ratios (STNRs) were determined, defined as the difference between the absolute sound pressure levels of MR noise and speech. The recorded noise of the MR sequences was played simultaneously with the recorded sentences at various intensities, and 15 healthy volunteers (seven women, eight men; median age, 27 years) repeated these sentences as accurately as possible. The STNR that corresponded with a 50% correct repetition was used as the measure for speech intelligibility. In addition, the effect of passive hearing protection on speech intelligibility was tested by using an earplug model. RESULTS Overall, speech understanding was reduced more at operator than at patient location. Most problematic were fast gradient-recalled-echo train and spiral k-space sequences. As the absolute sound pressure level of these sequences was approximately 100 dB at patient location, the vocal effort needed to attain 50% intelligibility was shouting (>77 dB). At operator location, less effort was required because of the lower sound pressure levels of the MR noise. Fast spoiled gradient-recalled-echo and echo-planar imaging sequences showed relatively favorable results with raised voice at operator location and loud speaking at patient location. The use of hearing protection slightly improved STNR. CONCLUSION At 1.5 T, the level of MR noise requires that large vocal effort is used, at the operator and especially at the patient location. Depending on the specific MR sequence used, loud speaking or shouting is needed to achieve adequate bidirectional communication with the patient. The wearing of earplugs improves speech intelligibility.
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Affiliation(s)
- Adriaan Moelker
- Department of Radiology, Erasmus Medical Center Rotterdam, 50 Dr Molewaterplein, PO Box 1738, 3000 DR Rotterdam, the Netherlands.
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Moelker A, Vogel MW, Pattynama PM. Real-time modulation of acoustic gradient noise in interventional MRI. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/cmr.b.20004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Moelker A, Vogel MW, Pattynama PMT. Efficacy of passive acoustic screening: implications for the design of imager and MR-suite. J Magn Reson Imaging 2003; 17:270-5. [PMID: 12541235 DOI: 10.1002/jmri.10251] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To investigate the efficacy of passive acoustic screening in the magnetic resonance (MR) environment by reducing direct and indirect MR-related acoustic noise, both from the patient's and health worker's perspective. MATERIALS AND METHODS Direct acoustic noise refers to sound originating from the inner and outer shrouds of the MR imager, and indirect noise to acoustic reflections from the walls of the MR suite. Sound measurements were obtained inside the magnet bore (patient position) and at the entrance of the MR imager (health worker position). Inner and outer shrouds and walls were lined with thick layers of sound insulation to eliminate the direct and indirect acoustic pathways. Sound pressure levels (SPLs) and octave band frequencies were acquired during various MR imaging sequences at 1.5 T. RESULTS Inside the magnet bore, direct acoustic noise radiating from the inner shroud was most relevant, with substantial reductions of up to 18.8 dB when using passive screening of the magnetic bore. At the magnet bore entrance, blocking acoustic noise from the outer shroud and reflections showed significant reductions of 4.5 and 2.8 dB, respectively, and 9.4 dB when simultaneously applied. Inner shroud coverage contributed minimally to the overall SPL reduction. CONCLUSION Maximum noise reduction by passive acoustic screening can be achieved by reducing direct sound conduction through the inner and outer shrouds. Additional measures to optimize the acoustic properties of the MR suite have only little effect.
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Affiliation(s)
- Adriaan Moelker
- Erasmus MC, University Medical Center Rotterdam, Department of Radiology, 50 Dr. Molewaterplein, 3015 GE Rotterdam, The Netherlands.
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