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Fritz V, Eisele S, Martirosian P, Machann J, Schick F. A straightforward procedure to build a non-toxic relaxometry phantom with desired T1 and T2 times at 3T. MAGMA (NEW YORK, N.Y.) 2024:10.1007/s10334-024-01166-7. [PMID: 38733487 DOI: 10.1007/s10334-024-01166-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 05/01/2024] [Accepted: 05/03/2024] [Indexed: 05/13/2024]
Abstract
OBJECTIVE To prepare and analyze soy-lecithin-agar gels for non-toxic relaxometry phantoms with tissue-like relaxation times at 3T. METHODS Phantoms mimicking the relaxation times of various tissues (gray and white matter, kidney cortex and medulla, spleen, muscle, liver) were built and tested with a clinical 3T whole-body MR scanner. Simple equations were derived to calculate the appropriate concentrations of soy lecithin and agar in aqueous solutions to achieve the desired relaxation times. Phantoms were tested for correspondence between measurements and calculated T1 and T2 values, reproducibility, spatial homogeneity, and temporal stability. T1 and T2 mapping techniques and a 3D T1-weighted sequence with high spatial resolution were applied. RESULTS Except for the liver relaxation phantom, all phantoms were successfully and reproducibly produced. Good agreement was found between the targeted and measured relaxation times. The percentage deviations from the targeted relaxation times were less than 3% for T1 and less than 6.5% for T2. In addition, the phantoms were homogeneous and had little to no air bubbles. However, the phantoms were unstable over time: after a storage period of 4 weeks, mold growth and also changes in relaxation times were detected in almost all phantoms. CONCLUSION Soy-lecithin-agar gels are a non-toxic material for the construction of relaxometry phantoms with tissue-like relaxation times. They are easy to prepare, inexpensive and allow independent adjustment of T1 and T2. However, there is still work to be done to improve the long-term stability of the phantoms.
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Affiliation(s)
- Victor Fritz
- Section of Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany.
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany.
- German Center for Diabetes Research (DZD), Neuherberg, Germany.
| | - Sabine Eisele
- Section of Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
| | - Petros Martirosian
- Section of Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
| | - Jürgen Machann
- Section of Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Fritz Schick
- Section of Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
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Gast LV, Platt T, Nagel AM, Gerhalter T. Recent technical developments and clinical research applications of sodium ( 23Na) MRI. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2023; 138-139:1-51. [PMID: 38065665 DOI: 10.1016/j.pnmrs.2023.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 12/18/2023]
Abstract
Sodium is an essential ion that plays a central role in many physiological processes including the transmembrane electrochemical gradient and the maintenance of the body's homeostasis. Due to the crucial role of sodium in the human body, the sodium nucleus is a promising candidate for non-invasively assessing (patho-)physiological changes. Almost 10 years ago, Madelin et al. provided a comprehensive review of methods and applications of sodium (23Na) MRI (Madelin et al., 2014) [1]. More recent review articles have focused mainly on specific applications of 23Na MRI. For example, several articles covered 23Na MRI applications for diseases such as osteoarthritis (Zbyn et al., 2016, Zaric et al., 2020) [2,3], multiple sclerosis (Petracca et al., 2016, Huhn et al., 2019) [4,5] and brain tumors (Schepkin, 2016) [6], or for imaging certain organs such as the kidneys (Zollner et al., 2016) [7], the brain (Shah et al., 2016, Thulborn et al., 2018) [8,9], and the heart (Bottomley, 2016) [10]. Other articles have reviewed technical developments such as radiofrequency (RF) coils for 23Na MRI (Wiggins et al., 2016, Bangerter et al., 2016) [11,12], pulse sequences (Konstandin et al., 2014) [13], image reconstruction methods (Chen et al., 2021) [14], and interleaved/simultaneous imaging techniques (Lopez Kolkovsky et al., 2022) [15]. In addition, 23Na MRI topics have been covered in review articles with broader topics such as multinuclear MRI or ultra-high-field MRI (Niesporek et al., 2019, Hu et al., 2019, Ladd et al., 2018) [16-18]. During the past decade, various research groups have continued working on technical improvements to sodium MRI and have investigated its potential to serve as a diagnostic and prognostic tool. Clinical research applications of 23Na MRI have covered a broad spectrum of diseases, mainly focusing on the brain, cartilage, and skeletal muscle (see Fig. 1). In this article, we aim to provide a comprehensive summary of methodological and hardware developments, as well as a review of various clinical research applications of sodium (23Na) MRI in the last decade (i.e., published from the beginning of 2013 to the end of 2022).
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Affiliation(s)
- Lena V Gast
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
| | - Tanja Platt
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Armin M Nagel
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Teresa Gerhalter
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
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Huang X, Chen L, Sha T, Lin Y, Zeng R, Xu J, Chen S, Cai HH, Zhang J, Zhou H, Sun PH, Jiang X. In Situ Tyrosinase Monitoring by Wearable Microneedle Patch toward Clinical Melanoma Screening. ACS NANO 2023; 17:20073-20086. [PMID: 37792448 DOI: 10.1021/acsnano.3c05638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Despite the potential indicating role of tyrosinase (TYR) in cutaneous melanoma, how to capture the real changes of TYR in suspicious skin remains a major challenge. Unlike the traditional human serum test, this study reports a sensing platform that incorporates a wearable microneedle (MN) patch and trimetallic Au@Ag-Pt nanoparticles (NPs) for surface-enhanced Raman scattering (SERS) and colorimetric dual-mode detecting TYR in human skin in situ toward potential melanoma screening. In the presence of TYR, catechol immobilized on MN is preferentially oxidized to benzoquinone, which competitively impedes the interaction of MN and Au@Ag-Pt NPs, triggering the SERS-colorimetric signal reciprocal switch. Using a B16F10 mouse melanoma model, our platform is capable of noninvasively piercing the skin surface and detecting TYR levels before and during anti-PD-1 antibody treatment, which would be highly informative for prognostic judgment and illness monitoring of melanoma. Through in situ sensing for capturing the metabolic changes of TYR in advance, this platform was successfully applied to discriminate the melanoma subjects from skin moles and normal ones (p < 0.001), as well as screen potential melanoma from lactate dehydrogenase (LDH)-negative patients. Melanoma growth and prognosis can still be monitored through recording the continuous change of TYR levels. More importantly, the well-defined flexible and stretchable characteristics of the MN patch allow robustly adhering to the skin without inducing chemical or physical irritation. We believe this platform integrating MN-based in situ sensing, TYR responsiveness, and SERS/colorimetric dual-readout strategy will have high clinical importance in early diagnosis and monitoring of cutaneous melanoma.
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Affiliation(s)
- Xueqin Huang
- The Second Clinical Medical College (Shenzhen People's Hospital), The Fifth Affiliated Hospital, College of Pharmacy, Jinan University, Guangzhou 510632, China
- Institute of Laboratory Medicine, Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, School of Medical Technology, the First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523000, China
| | - Lingzhi Chen
- The Second Clinical Medical College (Shenzhen People's Hospital), The Fifth Affiliated Hospital, College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Tianjian Sha
- The Second Clinical Medical College (Shenzhen People's Hospital), The Fifth Affiliated Hospital, College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Yongjian Lin
- College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China
| | - Runmin Zeng
- The Second Clinical Medical College (Shenzhen People's Hospital), The Fifth Affiliated Hospital, College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Jun Xu
- The Second Clinical Medical College (Shenzhen People's Hospital), The Fifth Affiliated Hospital, College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Shanze Chen
- The Second Clinical Medical College (Shenzhen People's Hospital), The Fifth Affiliated Hospital, College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Huai-Hong Cai
- College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China
| | - Jianglin Zhang
- The Second Clinical Medical College (Shenzhen People's Hospital), The Fifth Affiliated Hospital, College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Haibo Zhou
- The Second Clinical Medical College (Shenzhen People's Hospital), The Fifth Affiliated Hospital, College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Ping-Hua Sun
- The Second Clinical Medical College (Shenzhen People's Hospital), The Fifth Affiliated Hospital, College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Xingyu Jiang
- Shenzhen Key Laboratory of Smart Healthcare Engineering, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
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Tipirneni-Sajja A, Brasher S, Shrestha U, Johnson H, Morin C, Satapathy SK. Quantitative MRI of diffuse liver diseases: techniques and tissue-mimicking phantoms. MAGMA (NEW YORK, N.Y.) 2023; 36:529-551. [PMID: 36515810 DOI: 10.1007/s10334-022-01053-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/15/2022]
Abstract
Quantitative magnetic resonance imaging (MRI) techniques are emerging as non-invasive alternatives to biopsy for assessment of diffuse liver diseases of iron overload, steatosis and fibrosis. For testing and validating the accuracy of these techniques, phantoms are often used as stand-ins to human tissue to mimic diffuse liver pathologies. However, currently, there is no standardization in the preparation of MRI-based liver phantoms for mimicking iron overload, steatosis, fibrosis or a combination of these pathologies as various sizes and types of materials are used to mimic the same liver disease. Liver phantoms that mimic specific MR features of diffuse liver diseases observed in vivo are important for testing and calibrating new MRI techniques and for evaluating signal models to accurately quantify these features. In this study, we review the liver morphology associated with these diffuse diseases, discuss the quantitative MR techniques for assessing these liver pathologies, and comprehensively examine published liver phantom studies and discuss their benefits and limitations.
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Affiliation(s)
- Aaryani Tipirneni-Sajja
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN, USA.
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, USA.
| | - Sarah Brasher
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN, USA
| | - Utsav Shrestha
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN, USA
| | - Hayden Johnson
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN, USA
| | - Cara Morin
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, USA
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Sanjaya K Satapathy
- Northwell Health Center for Liver Diseases and Transplantation, Northshore University Hospital/Northwell Health, Manhasset, NY, USA
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5
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Antoniou A, Nikolaou A, Georgiou A, Evripidou N, Damianou C. Development of an US, MRI, and CT imaging compatible realistic mouse phantom for thermal ablation and focused ultrasound evaluation. ULTRASONICS 2023; 131:106955. [PMID: 36854247 DOI: 10.1016/j.ultras.2023.106955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/09/2022] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
Tissue mimicking phantoms (TMPs) play an essential role in modern biomedical research as cost-effective quality assurance and training tools, simultaneously contributing to the reduction of animal use. Herein, we present the development and evaluation of an anatomically accurate mouse phantom intended for image-guided thermal ablation and Focused Ultrasound (FUS) applications. The proposed mouse model consists of skeletal and soft tissue mimics, whose design was based on the Computed tomography (CT) scans data of a live mouse. Advantageously, it is compatible with US, CT, and Magnetic Resonance Imaging (MRI). The compatibility assessment was focused on the radiological behavior of the phantom due to the lack of relevant literature. The X-ray linear attenuation coefficient of candidate materials was estimated to assess the one that matches best the radiological behavior of living tissues. The bone part was manufactured by Fused Deposition Modeling (FDM) printing using Acrylonitrile styrene acrylate (ASA) material. For the soft-tissue mimic, a special mold was 3D printed having a cavity with the unique shape of the mouse body and filled with an agar-based silica-doped gel. The mouse phantom accurately matched the size and reproduced the body surface of the imaged mouse. Tissue-equivalency in terms of X-ray attenuation was demonstrated for the agar-based soft-tissue mimic. The phantom demonstrated excellent MRI visibility of the skeletal and soft-tissue mimics. Good radiological contrast between the skeletal and soft-tissue models was also observed in the CT scans. The model was also able to reproduce realistic behavior during trans-skull sonication as proved by thermocouple measurements. Overall, the proposed phantom is inexpensive, ergonomic, and realistic. It could constitute a powerful tool for image-guided thermal ablation and FUS studies in terms of testing and optimizing the performance of relevant equipment and protocols. It also possess great potential for use in transcranial FUS applications, including the emerging topic of FUS-mediated blood brain barrier (BBB) disruption.
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Affiliation(s)
- Anastasia Antoniou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, Limassol, Cyprus.
| | - Anastasia Nikolaou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, Limassol, Cyprus.
| | - Andreas Georgiou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, Limassol, Cyprus.
| | - Nikolas Evripidou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, Limassol, Cyprus.
| | - Christakis Damianou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, Limassol, Cyprus.
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6
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Stroud J, Hao Y, Read TS, Hankiewicz JH, Bilski P, Klodowski K, Brown JM, Rogers K, Stoll J, Camley RE, Celinski Z, Przybylski M. Magnetic particle based MRI thermometry at 0.2 T and 3 T. Magn Reson Imaging 2023; 100:43-54. [PMID: 36933774 DOI: 10.1016/j.mri.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/28/2023] [Accepted: 03/12/2023] [Indexed: 03/18/2023]
Abstract
This study provides insight into the advantages and disadvantages of using ferrite particles embedded in agar gel phantoms as MRI temperature indicators for low-magnetic field scanners. We compare the temperature-dependent intensity of MR images at low-field (0.2 T) to those at high-field (3.0 T). Due to a shorter T1 relaxation time at low-fields, MRI scanners operating at 0.2 T can use shorter repetition times and achieve a significant T2⁎ weighting, resulting in strong temperature-dependent changes of MR image brightness in short acquisition times. Although the signal-to-noise ratio for MR images at 0.2 T MR is much lower than at 3.0 T, it is sufficient to achieve a temperature measurement uncertainty of about ±1.0 °C at 37 °C for a 90 μg/mL concentration of magnetic particles.
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Affiliation(s)
- John Stroud
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Yu Hao
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Tim S Read
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Janusz H Hankiewicz
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Pawel Bilski
- Department of Physics, A. Mickiewicz University, Uniwersytetu Poznanskiego St. 2, 61-614 Poznan, Poland
| | - Krzysztof Klodowski
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza Ave. 30, 30-059 Kraków, Poland
| | - Jared M Brown
- Colorado Center for Nanomedicine and Nanosafety, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States
| | - Keegan Rogers
- Colorado Center for Nanomedicine and Nanosafety, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States
| | - Josh Stoll
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Robert E Camley
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Zbigniew Celinski
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Marek Przybylski
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza Ave. 30, 30-059 Kraków, Poland; Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Mickiewicza Ave. 30, 30-059 Kraków, Poland.
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Motovilova E, Aronowitz E, Vincent J, Shin J, Tan ET, Robb F, Taracila V, Sneag DB, Dyke JP, Winkler SA. Silicone-based materials with tailored MR relaxation characteristics for use in reduced coil visibility and in tissue-mimicking phantom design. Med Phys 2023. [PMID: 36737839 DOI: 10.1002/mp.16255] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 12/24/2022] [Accepted: 01/15/2023] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The development of materials with tailored signal intensity in MR imaging is critically important both for the reduction of signal from non-tissue hardware, as well as for the construction of tissue-mimicking phantoms. Silicone-based phantoms are becoming more popular due to their structural stability, stretchability, longer shelf life, and ease of handling, as well as for their application in dynamic imaging of physiology in motion. Moreover, silicone can be also used for the design of stretchable receive radio-frequency (RF) coils. PURPOSE Fabrication of materials with tailored signal intensity for MRI requires knowledge of precise T1 and T2 relaxation times of the materials used. In order to increase the range of possible relaxation times, silicone materials can be doped with gadolinium (Gd). In this work, we aim to systematically evaluate relaxation properties of Gd-doped silicone material at a broad range of Gd concentrations and at three clinically relevant magnetic field strengths (1.5 T, 3 T, and 7 T). We apply the findings for rendering silicone substrates of stretchable receive RF coils less visible in MRI. Moreover, we demonstrate early stage proof-of-concept applicability in tissue-mimicking phantom development. MATERIALS AND METHODS Ten samples of pure and Gd-doped Ecoflex silicone polymer samples were prepared with various Gd volume ratios ranging from 1:5000 to 1:10, and studied using 1.5 T and 3 T clinical and 7 T preclinical scanners. T1 and T2 relaxation times of each sample were derived by fitting the data to Bloch signal intensity equations. A receive coil made from Gd-doped Ecoflex silicone polymer was fabricated and evaluated in vitro at 3 T. RESULTS With the addition of a Gd-based contrast agent, it is possible to significantly change T2 relaxation times of Ecoflex silicone polymer (from 213 ms to 20 ms at 1.5 T; from 135 ms to 17 ms at 3 T; and from 111.4 ms to 17.2 ms at 7 T). T1 relaxation time is less affected by the introduction of the contrast agent (changes from 608 ms to 579 ms; from 802.5 ms to 713 ms at 3 T; from 1276 ms to 979 ms at 7 T). First results also indicate that liver, pancreas, and white matter tissues can potentially be closely mimicked using this phantom preparation technique. Gd-doping reduces the appearance of the silicone-based coil substrate during the MR scan by up to 81%. CONCLUSIONS Gd-based contrast agents can be effectively used to create Ecoflex silicone polymer-based phantoms with tailored T2 relaxation properties. The relative low cost, ease of preparation, stretchability, mechanical stability, and long shelf life of Ecoflex silicone polymer all make it a good candidate for "MR invisible" coil development and bears promise for tissue-mimicking phantom development applicability.
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Affiliation(s)
- Elizaveta Motovilova
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA.,Department of Radiology, Hospital for Special Surgery, New York, New York, USA
| | - Eric Aronowitz
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA
| | | | - James Shin
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA
| | - Ek Tsoon Tan
- Department of Radiology, Hospital for Special Surgery, New York, New York, USA
| | | | | | - Darryl B Sneag
- Department of Radiology, Hospital for Special Surgery, New York, New York, USA
| | - Jonathan P Dyke
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA
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Kilian D, Kilian W, Troia A, Nguyen TD, Ittermann B, Zilberti L, Gelinsky M. 3D Extrusion Printing of Biphasic Anthropomorphic Brain Phantoms Mimicking MR Relaxation Times Based on Alginate-Agarose-Carrageenan Blends. ACS APPLIED MATERIALS & INTERFACES 2022; 14:48397-48415. [PMID: 36270624 PMCID: PMC9634698 DOI: 10.1021/acsami.2c12872] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
The availability of adapted phantoms mimicking different body parts is fundamental to establishing the stability and reliability of magnetic resonance imaging (MRI) methods. The primary purpose of such phantoms is the mimicking of physiologically relevant, contrast-creating relaxation times T1 and T2. For the head, frequently examined by MRI, an anthropomorphic design of brain phantoms would imply the discrimination of gray matter and white matter (WM) within defined, spatially distributed compartments. Multichannel extrusion printing allows the layer-by-layer fabrication of multiple pastelike materials in a spatially defined manner with a predefined shape. In this study, the advantages of this method are used to fabricate biphasic brain phantoms mimicking MR relaxation times and anthropomorphic geometry. The printable ink was based on purely naturally derived polymers: alginate as a calcium-cross-linkable gelling agent, agarose, ι-carrageenan, and GdCl3 in different concentrations (0-280 μmol kg-1) as the paramagnetic component. The suggested inks (e.g., 3Alg-1Agar-6Car) fulfilled the requirements of viscoelastic behavior and printability of large constructs (>150 mL). The microstructure and distribution of GdCl3 were assessed by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX). In closely monitored steps of technological development and characterization, from monophasic and biphasic samples as printable inks and cross-linked gels, we describe the construction of large-scale phantom models whose relaxation times were characterized and checked for stability over time.
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Affiliation(s)
- David Kilian
- Centre
for Translational Bone, Joint and Soft Tissue Research, Faculty of
Medicine Carl Gustav Carus, Technische Universität
Dresden (TUD), Dresden01307, Germany
| | - Wolfgang Kilian
- Physikalisch-Technische
Bundesanstalt (PTB), Berlin10587, Germany
| | - Adriano Troia
- Istituto
Nazionale di Ricerca Metrologica (INRiM), Turin10135, Italy
| | - Thanh-Duc Nguyen
- Centre
for Translational Bone, Joint and Soft Tissue Research, Faculty of
Medicine Carl Gustav Carus, Technische Universität
Dresden (TUD), Dresden01307, Germany
| | - Bernd Ittermann
- Physikalisch-Technische
Bundesanstalt (PTB), Berlin10587, Germany
| | - Luca Zilberti
- Istituto
Nazionale di Ricerca Metrologica (INRiM), Turin10135, Italy
| | - Michael Gelinsky
- Centre
for Translational Bone, Joint and Soft Tissue Research, Faculty of
Medicine Carl Gustav Carus, Technische Universität
Dresden (TUD), Dresden01307, Germany
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Development of a standard phantom for diffusion-weighted magnetic resonance imaging quality control studies: A review. POLISH JOURNAL OF MEDICAL PHYSICS AND ENGINEERING 2022. [DOI: 10.2478/pjmpe-2022-0020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Abstract
Various materials and compounds have been used in the design of diffusion-weighted magnetic resonance imaging (DWMRI) phantoms to mimic biological tissue properties, including diffusion. This review thus provides an overview of the preparations of the various DW-MRI phantoms available in relation to the limitations and strengths of materials/solutions used to fill them. The narrative review conducted from relevant databases shows that synthesizing all relevant compounds from individual liquids, gels, and solutions based on their identified strengths could contribute to the development of a novel multifunctional DW-MRI phantom. The proposed multifunctional material at varied concentrations, when filled into a multi-compartment Perspex container of cylindrical or spherical geometry, could serve as a standard DW-MRI phantom. The standard multifunctional phantom could potentially provide DW-MRI quality control test parameters in one study session.
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10
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Bouattour Y, Sautou V, Hmede R, El Ouadhi Y, Gouot D, Chennell P, Lapusta Y, Chapelle F, Lemaire JJ. A Minireview on Brain Models Simulating Geometrical, Physical, and Biochemical Properties of the Human Brain. Front Bioeng Biotechnol 2022; 10:818201. [PMID: 35419353 PMCID: PMC8996142 DOI: 10.3389/fbioe.2022.818201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/08/2022] [Indexed: 11/13/2022] Open
Abstract
There is a growing body of evidences that brain surrogates will be of great interest for researchers and physicians in the medical field. They are currently mainly used for education and training purposes or to verify the appropriate functionality of medical devices. Depending on the purpose, a variety of materials have been used with specific and accurate mechanical and biophysical properties, More recently they have been used to assess the biocompatibility of implantable devices, but they are still not validated to study the migration of leaching components from devices. This minireview shows the large diversity of approaches and uses of brain phantoms, which converge punctually. All these phantoms are complementary to numeric models, which benefit, reciprocally, of their respective advances. It also suggests avenues of research for the analysis of leaching components from implantable devices.
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Affiliation(s)
- Yassine Bouattour
- Université Clermont Auvergne, CHU Clermont Ferrand, Clermont Auvergne INP, CNRS, ICCF, F-63000, Clermont-Ferrand, France
- *Correspondence: Yassine Bouattour, ; Jean-Jacques Lemaire,
| | - Valérie Sautou
- Université Clermont Auvergne, CHU Clermont Ferrand, Clermont Auvergne INP, CNRS, ICCF, F-63000, Clermont-Ferrand, France
| | - Rodayna Hmede
- Universite Clermont Auvergne, CNRS, Clermont Auvergne INP, Institut Pascal, F-63000, Clermont-Ferrand, France
| | - Youssef El Ouadhi
- Universite Clermont Auvergne, CNRS, Clermont Auvergne INP, Institut Pascal, F-63000, Clermont-Ferrand, France
- Service de Neurochirurgie, CHU Clermont Ferrand, F-63000, Clermont-Ferrand, France
| | - Dimitri Gouot
- Universite Clermont Auvergne, CNRS, Clermont Auvergne INP, Institut Pascal, F-63000, Clermont-Ferrand, France
| | - Philip Chennell
- Université Clermont Auvergne, CHU Clermont Ferrand, Clermont Auvergne INP, CNRS, ICCF, F-63000, Clermont-Ferrand, France
| | - Yuri Lapusta
- Universite Clermont Auvergne, CNRS, Clermont Auvergne INP, Institut Pascal, F-63000, Clermont-Ferrand, France
| | - Frédéric Chapelle
- Universite Clermont Auvergne, CNRS, Clermont Auvergne INP, Institut Pascal, F-63000, Clermont-Ferrand, France
| | - Jean-Jacques Lemaire
- Universite Clermont Auvergne, CNRS, Clermont Auvergne INP, Institut Pascal, F-63000, Clermont-Ferrand, France
- Service de Neurochirurgie, CHU Clermont Ferrand, F-63000, Clermont-Ferrand, France
- *Correspondence: Yassine Bouattour, ; Jean-Jacques Lemaire,
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Chauhan M, Sadleir R. Phantom Construction and Equipment Configurations for Characterizing Electrical Properties Using MRI. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1380:83-110. [PMID: 36306095 DOI: 10.1007/978-3-031-03873-0_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Phantom objects are commonly employed in MRI systems as stable substitutes for biological tissues to ensure systems for measuring images are operating correctly and safely. For magnetic resonance electrical impedance tomography (MREIT) and magnetic resonance electrical property tomography (MREPT), conductivity or permittivity phantoms play an important role in checking MRI pulse sequences, MREIT equipment performance, and algorithm validation. The construction of these phantoms is explained in this chapter. In the first part, materials used for phantom construction are introduced. Ingredients for modifying the electromagnetic properties and relaxation times are presented, and the advantages and disadvantages of aqueous, gel, and hybrid conductivity phantoms are explained. The devices and methods used to confirm phantom electromagnetic properties are explained. Next, different types of MREIT electrode materials and the constant current sources used for MREIT studies are discussed. In the last section, we present the results of previous MREIT and MREPT studies.
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Affiliation(s)
- Munish Chauhan
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Rosalind Sadleir
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA.
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Er WX, Lim WJ, Dwihapsari Y, Awang MNA, Yusoff AN. Signal-to-noise ratio uniformity and stability of agar gel phantom with iron (III) oxide as relaxation modifier. BENI-SUEF UNIVERSITY JOURNAL OF BASIC AND APPLIED SCIENCES 2021. [DOI: 10.1186/s43088-021-00173-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Abstract
Background
Agar has been commonly used as one of the materials to fabricate magnetic resonance imaging phantoms in the past few decades. In this study, eleven agar gel phantoms with different iron (III) oxide (Fe2O3) masses were prepared. This study was aimed to evaluate the signal-to-noise ratio (SNR) uniformity and stability of agar gel phantoms with and without the addition of Fe2O3 at two different time points (TPs). Fe2O3 powder was used as a relaxation modifier to manipulate and produce various SNR, T1 and T2 values. These phantoms were scanned using turbo spin echo pulse sequence to produce T1- and T2-measurement images. The SNR was then computed by plotting 1, 3 and 25 regions of interest on the images using ImageJ software. The T1 and T2 relaxation equations were then fitted to the experimental results of SNR versus TR and SNR versus TE curves for the determination of saturation (SNRo), T1 and T2 values.
Results
The results demonstrated that the agar gel phantoms were able to maintain SNR uniformity but not SNR stability after 4 weeks of phantom preparation. The change in the water content and microstructure of the phantoms have no significant effect on T2 relaxation but on T1 relaxation. The T1 and T2 of the agar gel phantoms were minimally affected although there was a systemic increase in the content of the Fe2O3 powder.
Conclusions
It can be concluded that the agar gel phantoms exhibited the characteristics of SNR uniformity, but they showed instability of SNR at TP2. The Fe2O3 in powder form is not an effective relaxation modifier to reduce the T1 and T2 when it is introduced into the agar gel phantoms. Dissolved nanosized particles should be the focus of future studies.
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Drobnjak I, Neher P, Poupon C, Sarwar T. Physical and digital phantoms for validating tractography and assessing artifacts. Neuroimage 2021; 245:118704. [PMID: 34748954 DOI: 10.1016/j.neuroimage.2021.118704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 10/01/2021] [Accepted: 11/01/2021] [Indexed: 11/17/2022] Open
Abstract
Fiber tractography is widely used to non-invasively map white-matter bundles in vivo using diffusion-weighted magnetic resonance imaging (dMRI). As it is the case for all scientific methods, proper validation is a key prerequisite for the successful application of fiber tractography, be it in the area of basic neuroscience or in a clinical setting. It is well-known that the indirect estimation of the fiber tracts from the local diffusion signal is highly ambiguous and extremely challenging. Furthermore, the validation of fiber tractography methods is hampered by the lack of a real ground truth, which is caused by the extremely complex brain microstructure that is not directly observable non-invasively and that is the basis of the huge network of long-range fiber connections in the brain that are the actual target of fiber tractography methods. As a substitute for in vivo data with a real ground truth that could be used for validation, a widely and successfully employed approach is the use of synthetic phantoms. In this work, we are providing an overview of the state-of-the-art in the area of physical and digital phantoms, answering the following guiding questions: "What are dMRI phantoms and what are they good for?", "What would the ideal phantom for validation fiber tractography look like?" and "What phantoms, phantom datasets and tools used for their creation are available to the research community?". We will further discuss the limitations and opportunities that come with the use of dMRI phantoms, and what future direction this field of research might take.
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Affiliation(s)
- Ivana Drobnjak
- Center for Medical Image Computing, Department of Computer Science, University College London, UK.
| | - Peter Neher
- Division of Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Cyril Poupon
- BAOBAB, NeuroSpin, Commissariat à l'Energie Atomique, Institut des Sciences du Vivant Frédéric Joliot, Gif-sur-Yvette, France
| | - Tabinda Sarwar
- School of Computing Technologies, RMIT University, Australia
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Fritz V, Martirosian P, Machann J, Daniels R, Schick F. A comparison of emulsifiers for the formation of oil-in-water emulsions: stability of the emulsions within 9 h after production and MR signal properties. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2021; 35:401-410. [PMID: 34698962 PMCID: PMC9188495 DOI: 10.1007/s10334-021-00970-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 11/21/2022]
Abstract
Objective To provide a basis for the selection of suitable emulsifiers in oil-in-water emulsions used as tissue analogs for MRI experiments. Three different emulsifiers were investigated with regard to their ability to stabilize tissue-like oil-in-water emulsions. Furthermore, MR signal properties of the emulsifiers themselves and influences on relaxation times and ADC values of the aqueous phase were investigated. Materials and methods Polysorbate 60, sodium dodecyl sulfate (SDS) and soy lecithin were used as emulsifiers. MR characteristics of emulsifiers were assessed in aqueous solutions and their function as a stabilizer was examined in oil-in-water emulsions of varying fat content (10, 20, 30, 40, 50%). Stability and homogeneity of the oil-in-water emulsions were evaluated with a delay of 3 h and 9 h after preparation using T1 mapping and visual control. Signal properties of the emulsifiers were investigated by 1H-MRS in aqueous emulsifier solutions. Relaxometry and diffusion weighted MRI (DWI) were performed to investigate the effect of various emulsifier concentrations on relaxation times (T1 and T2) and ADC values of aqueous solutions. Results Emulsions stabilized by polysorbate 60 or soy lecithin were stable and homogeneous across all tested fat fractions. In contrast, emulsions with SDS showed a significantly lower stability and homogeneity. Recorded T1 maps revealed marked creaming of oil droplets in almost all of the emulsions with SDS. The spectral analysis showed several additional signals for polysorbate and SDS. However, lecithin remained invisible in 1H-MRS. Relaxometry and DWI revealed different influences of the emulsifiers on water: Polysorbate and SDS showed only minor effects on relaxation times and ADC values of aqueous solutions, whereas lecithin showed a strong decrease in both relaxation times (r1,lecithin = 0.11 wt.%−1 s−1, r2,lecithin = 0.57 wt.%−1 s−1) and ADC value (Δ(ADC)lecithin = − 0.18 × 10–3 mm2/s⋅wt.%) with increasing concentration. Conclusion Lecithin is suggested as the preferred emulsifier of oil-in-water emulsions in MRI as it shows a high stabilizing ability and remains invisible in MRI experiments. In addition, lecithin is suitable as an alternative means of adjusting relaxation times and ADC values of water.
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Affiliation(s)
- Victor Fritz
- Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tuebingen, Tuebingen, Germany.
| | - Petros Martirosian
- Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tuebingen, Tuebingen, Germany
| | - Jürgen Machann
- Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tuebingen, Tuebingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tuebingen, Tuebingen, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Rolf Daniels
- Institute of Pharmaceutical Technology, University of Tuebingen, Tuebingen, Germany
| | - Fritz Schick
- Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tuebingen, Tuebingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tuebingen, Tuebingen, Germany
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Crasto N, Kirubarajan A, Sussman D. Anthropomorphic brain phantoms for use in MRI systems: a systematic review. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2021; 35:277-289. [PMID: 34463866 DOI: 10.1007/s10334-021-00953-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/13/2021] [Accepted: 08/16/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To provide a systematic review of available brain MRI phantoms for comparison of structural and functional characteristics. MATERIALS AND METHODS Phantoms were identified from a literature search using two databases including Google Scholar and PubMed. Narrow inclusion criteria were followed for identification of only tissue-mimicking MRI phantoms excluding digital, computational, or numerical phantoms. Assessment criteria for the identified phantoms was based on three categories being anatomical accuracy, tissue-mimicking materials, and exhibiting relaxation times approximating in-vivo tissues. The available features and uses of each phantom were reported and discussed using the assessment criteria. RESULTS Ten phantoms were identified after screening; each proposed phantom was then summarized in a table (Table 2). Significant features and characteristics were shown in the comparisons of phantom type in each category, being anthropomorphic vs. traditional phantoms. Anthropomorphic phantoms had more anatomically accurate features than traditional phantoms. On the other hand, traditional phantoms commonly used effective tissue-mimicking materials and accurate electromagnetic properties. DISCUSSION The findings provide an overview of the different proposed tissue-mimicking MRI brain phantoms available. Various uses and features are highlighted by comparing criteria such as anatomical accuracy, tissue-mimicking material, and electromagnetic properties. Tissue-mimicking MRI phantoms are an extremely useful tool for researchers and clinicians. Future applications include personalized phantom technology and validation of MR imaging and segmentation methods.
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Affiliation(s)
- Noelle Crasto
- Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST) at Ryerson University and St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada
| | - Abirami Kirubarajan
- Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, L8S 4L8, Canada
| | - Dafna Sussman
- Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada.
- Institute for Biomedical Engineering, Science and Technology (iBEST) at Ryerson University and St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada.
- The Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada.
- Department of Biomedical Physics, Ryerson University, Toronto, ON, M5B 2K3, Canada.
- Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Toronto, Toronto, M5S 1A8, Canada.
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16
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Woletz M, Roat S, Hummer A, Tik M, Windischberger C. Technical Note: Human tissue-equivalent MRI phantom preparation for 3 and 7 Tesla. Med Phys 2021; 48:4387-4394. [PMID: 34018625 DOI: 10.1002/mp.14986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/31/2021] [Accepted: 05/07/2021] [Indexed: 12/22/2022] Open
Abstract
PURPOSE While test objects (phantoms) in magnetic resonance imaging (MRI) are crucial for sequence development, protocol validation, and quality control, studies on the preparation of phantoms have been scarce, particularly at fields exceeding 3 Tesla. Here, we present a framework for the preparation of phantoms with well-defined T1 and T2 times at 3 and 7 Tesla. METHODS Phantoms with varying concentrations of agarose and Gd-DTPA were prepared and measured at 3 and 7 Tesla using T1 and T2 mapping techniques. An empirical, polynomial model was constructed that best represents the data at both field strengths, enabling the preparation of new phantoms with specified combinations of both T1 and T2 . Instructions for three different tissue types (brain gray matter, brain white matter, and renal cortex) are presented and validated. RESULTS T1 times in the samples ranged from 698 to 2820 ms and from 695 to 2906 ms, whereas T2 times ranged from 39 to 227 ms and from 34 to 235 ms for 3 and 7 Tesla scans, respectively. Models for both relaxation times used six parameters to represent the data with an adjusted R² of 0.998 and 0.997 for T1 and T2 , respectively. CONCLUSION Based on the equations derived from the current study, it is now possible to obtain accurate weight specifications for a test object with desired T1 and T2 relaxation times. This will spare researchers the laborious task of trail-and-error approaches in test object preparation attempts.
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Affiliation(s)
- Michael Woletz
- High-field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Sigrun Roat
- High-field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Allan Hummer
- High-field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Martin Tik
- High-field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Christian Windischberger
- High-field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, Vienna, 1090, Austria
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Wereszczyńska B, Szcześniak K. MRI phantom for tissue simulation with respect to diffusion coefficient and kurtosis - Validation with injection of liposomal theranostics. Magn Reson Imaging 2021; 82:18-23. [PMID: 34147600 DOI: 10.1016/j.mri.2021.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 04/22/2021] [Accepted: 06/15/2021] [Indexed: 10/21/2022]
Abstract
This study presents gelatine-based and agar-based phantoms with an addition of glycerol, safflower oil, silicone oil and cellulose microcrystalline with a potential to cover the entire range of tissue diffusion coefficients and kurtosis values. Forty types of phantoms were prepared and examined for NMR relaxation times T1 and T2 and diffusional metrics D, K and ADC. Wide ranges of values of D (0.0003-0.0031 mm2s-1), K (0.00-7.24) and ADC (0.0002-0.0031 mm2s-1) were observed. Two of the phantoms closely mimic muscle and cortical gray matter with respect to water diffusion parameters. Although many of the presented phantoms display both D and K values within the range of human tissues, they match different tissues with respect to D and K. The imaging results for the gray matter simulating phantom injected with the liposomal solution, bear a resemblance to the particle size effect described in the literature. The phantoms presented in this work are simple in preparation and affordable tissue-simulating materials to be used primarily in development of diffusion kurtosis-based MRI methods and possibly in a preliminary assessment of MRI contrast agents. Further adjustments of the chemical compositions could potentially lead to development of new types of phantoms mimicking diffusional properties of more kinds of soft tissues.
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Affiliation(s)
- B Wereszczyńska
- NanoBioMedical Centre, Adam Mickiewicz University, Poznan, Poland; Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland.
| | - K Szcześniak
- Department of Polymers, Faculty of Chemical Technology, Institute of Chemical Technology and Engineering, Poznan University of Technology, Poznan, Poland
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Leppanen J, Stone H, Lythgoe DJ, Williams S, Horvath B. Sailing in rough waters: Examining volatility of fMRI noise. Magn Reson Imaging 2021; 78:69-79. [PMID: 33588017 PMCID: PMC7992030 DOI: 10.1016/j.mri.2021.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/25/2020] [Accepted: 02/09/2021] [Indexed: 11/20/2022]
Abstract
Background The assumption that functional magnetic resonance imaging (fMRI) noise has constant volatility has recently been challenged by studies examining heteroscedasticity arising from head motion and physiological noise. The present study builds on this work using latest methods from the field of financial mathematics to model fMRI noise volatility. Methods Multi-echo phantom and human fMRI scans were used and realised volatility was estimated. The Hurst parameter H ∈ (0, 1), which governs the roughness/irregularity of realised volatility time series, was estimated. Calibration of H was performed pathwise, using well-established neural network calibration tools. Results In all experiments the volatility calibrated to values within the rough case, H < 0.5, and on average fMRI noise was very rough with 0.03 < H < 0.05. Some edge effects were also observed, whereby H was larger near the edges of the phantoms. Discussion The findings suggest that fMRI volatility is not only non-constant, but also substantially more irregular than a standard Brownian motion. Thus, further research is needed to examine the impact such pronounced oscillations in the volatility of fMRI noise have on data analyses.
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Affiliation(s)
| | - Henry Stone
- Department of Mathematics, Imperial College London, UK
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Barucci A, Flori A, Carpi R, Marchi DD, Esposito M, Menichetti L, Pini R, Ratto F, Belli G, Piazza F. Ficoll as testing material for diffusion weighted imaging-quality assurance phantoms. Magn Reson Imaging 2020; 76:1-7. [PMID: 33161101 DOI: 10.1016/j.mri.2020.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 11/03/2020] [Accepted: 11/03/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE The aim of this work is to test the use of aqueous solutions of Ficoll®**, a highly branched polymer displaying crowding properties, to build a phantom suitable for Diffusion Weighted Imaging (DWI) in Magnetic Resonance Imaging (MRI). METHODS We developed a test object made of a cylindrical plastic container with a precise geometrical arrangement suitable for measuring several samples at the same time. The container was designed to host single vials with variable geometry and number, and to fit inside common commercial head coils for MRI scanners. In our experiments, vials were filled with 8 aqueous solutions of Ficoll 70 and Ficoll 400 spanning a range of polymer concentration from 5 to 30% by weight. Vials containing ultra-pure water were also used as reference. Experiments were performed on both 1.5 and 3 T clinical scanners (GE, Philips and Siemens), under the conditions of a standard clinical examination. RESULTS The geometry of the phantom provided reduced imaging artifacts, especially image distortions at magnetic interfaces. We found that the Apparent Diffusion Coefficient (ADC) varied in the range of 0.00125-0.00223 mm2/s and decreased with Ficoll concentration. ADC vs Ficoll concentration exhibited a linear trend. Results were consistent over time and among different MRI clinical scanners, showing an average variability of 3% at 1.5 T and of 7.5% at 3 T. Moreover, no substantial difference was found between Ficoll 70 and 400. By varying Ficoll concentration, ADC can be modulated to approach tissue-mimicking values. Preliminary results for relaxation measurements proved that both T1 and T2 decreased with Ficoll concentration in the ranges 1.3-2.4 s and 150-800 ms respectively. CONCLUSIONS In this work, we propose a 3D phantom design based on the widespread crowding agent Ficoll, which is suitable for DWI quality assurance purposes in MRI acquisitions. Aqueous Ficoll solutions provide good performance in terms of stability, ease of preparation, and safety.
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Affiliation(s)
- Andrea Barucci
- "Nello Carrara" Institute of Applied Physics, CNR Florence Research Area, Via Madonna del Piano 10, 50019 Sesto Fiorentino, FI, Italy.
| | - Alessandra Flori
- Bioengineering and clinical engineering unit, Fondazione CNR/Regione Toscana G. Monasterio, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Roberto Carpi
- USL Toscana Centro, Piazza Santa Maria Nuova 1, 50121 Firenze, Italy
| | - Daniele De Marchi
- MRI unit, Fondazione CNR/Regione Toscana G. Monasterio, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Marco Esposito
- USL Toscana Centro, Piazza Santa Maria Nuova 1, 50121 Firenze, Italy
| | - Luca Menichetti
- Institute of Clinical Physiology, CNR, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Roberto Pini
- "Nello Carrara" Institute of Applied Physics, CNR Florence Research Area, Via Madonna del Piano 10, 50019 Sesto Fiorentino, FI, Italy
| | - Fulvio Ratto
- "Nello Carrara" Institute of Applied Physics, CNR Florence Research Area, Via Madonna del Piano 10, 50019 Sesto Fiorentino, FI, Italy
| | - Giacomo Belli
- Health Physics Unit, AOU Careggi, Largo Brambilla 3, 50134 Firenze, Italy
| | - Francesco Piazza
- Université d'Orléans and Centre de Biophysique Moléculaire (CBM), CNRS UPR 4301, rue Charles Sadron, 45071 Orléans, France
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Fagerstrom JM, Kaur S. Simple phantom fabrication for MRI-based HDR brachytherapy applicator commissioning. J Appl Clin Med Phys 2020; 21:283-287. [PMID: 33016469 PMCID: PMC7700937 DOI: 10.1002/acm2.13039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/27/2020] [Accepted: 09/01/2020] [Indexed: 11/26/2022] Open
Abstract
A new high dose rate (HDR) brachytherapy program was initiated in a community hospital setting, with the goal of using magnetic resonance (MR) images with the implant in place during the planning process. Physics acceptance testing and commissioning was completed for key program components, including multiple applicators. To image new applicators for MRI‐based planning prior to use with patients, agar gel doped with copper sulfate was created using simple, MR‐safe household materials as a practical and inexpensive alternative to custom‐machined precision phantoms. Applicators in‐phantom were scanned in a 1.5 T MRI scanner using the same sequences developed for the brachytherapy program, then rigidly registered to high‐resolution computed tomography (CT) images to assess distortion, artifact, and geometric displacement. To date, Varian tandem and ring sets, segmented cylinders, cervical probes, endometrial applicators; and third‐party plastic needles, tandems, and vaginal guides have been imaged in phantom and are available for use clinically.
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Affiliation(s)
- Jessica M Fagerstrom
- Northwest Medical Physics Center, Lynnwood, WA, USA.,Kaiser Permanente, Seattle, WA, USA
| | - Sukhjit Kaur
- Northwest Medical Physics Center, Lynnwood, WA, USA
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Saccharomyces cerevisiae and Candida albicans Yeast Cells Labeled with Fe(III) Complexes as MRI Probes. MAGNETOCHEMISTRY 2020. [DOI: 10.3390/magnetochemistry6030041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The development of MRI probes is of interest for labeling antibiotic-resistant fungal infections based on yeast. Our work showed that yeast cells can be labeled with high-spin Fe(III) complexes to produce enhanced T2 water proton relaxation. These Fe(III)-based macrocyclic complexes contained a 1,4,7-triazacyclononane framework, two pendant alcohol groups, and either a non-coordinating ancillary group and a bound water molecule or a third coordinating pendant. The Fe(III) complexes that had an open coordination site associated strongly with Saccharomyces cerevisiae upon incubation, as shown by screening using Z-spectra analysis. The incubation of one Fe(III) complex with either Saccharomyces cerevisiae or Candida albicans yeast led to an interaction with the β-glucan-based cell wall, as shown by the ready retrieval of the complex by the bidentate chelator called maltol. Other conditions, such as a heat shock treatment of the complexes, produced Fe(III) complex uptake that could not be reversed by the addition of maltol. Appending a fluorescence dye to Fe(TOB) led to uptake through secretory pathways, as shown by confocal fluorescence microscopy and by the incomplete retrieval of the Fe(III) complex by the maltol treatment. Yeast cells that were labeled with these Fe(III) complexes displayed enhanced water proton T2 relaxation, both for S. cerevisiae and for yeast and hyphal forms of C. albicans.
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Harries J, Jochimsen TH, Scholz T, Schlender T, Barthel H, Sabri O, Sattler B. A realistic phantom of the human head for PET-MRI. EJNMMI Phys 2020; 7:52. [PMID: 32757099 PMCID: PMC7406590 DOI: 10.1186/s40658-020-00320-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 07/16/2020] [Indexed: 12/27/2022] Open
Abstract
Background The combination of positron emission tomography (PET) and magnetic resonance imaging (MRI) (PET-MRI) is a unique hybrid imaging modality mainly used in oncology and neurology. The MRI-based attenuation correction (MRAC) is crucial for correct quantification of PET data. A suitable phantom to validate quantitative results in PET-MRI is currently missing. In particular, the correction of attenuation due to bone is usually not verified by commonly available phantoms. The aim of this work was, thus, the development of such a phantom and to explore whether such a phantom might be used to validate MRACs. Method Various materials were investigated for their attenuation and MR properties. For the substitution of bone, water-saturated gypsum plaster was used. The attenuation of 511 keV annihilation photons was regulated by addition of iodine. Adipose tissue was imitated by silicone and brain tissue by agarose gel, respectively. The practicability with respect to the comparison of MRACs was checked as follows: A small flask inserted into the phantom and a large spherical phantom (serving as a reference with negligible error in MRAC) were filled with the very same activity concentration. The activity concentration was measured and compared using clinical protocols on PET-MRI and different built-in and offline MRACs. The same measurements were carried out using PET-CT for comparison. Results The phantom imitates the human head in sufficient detail. All tissue types including bone were detected as such so that the phantom-based comparison of the quantification accuracy of PET-MRI was possible. Quantitatively, the activity concentration in the brain, which was determined using different MRACs, showed a deviation of about 5% on average and a maximum deviation of 11% compared to the spherical phantom. For PET-CT, the deviation was 5%. Conclusions The comparatively small error in quantification indicates that it is possible to construct a brain PET-MRI phantom that leads to MR-based attenuation-corrected images with reasonable accuracy.
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Affiliation(s)
- Johanna Harries
- Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig, Germany.,Department of Radiation Safety and Medical Physics, Medizinische Hochschule Hannover, Carl-Neuberg Straße 1, Hannover, Germany
| | - Thies H Jochimsen
- Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig, Germany.
| | - Thomas Scholz
- Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig, Germany
| | - Tina Schlender
- Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig, Germany
| | - Osama Sabri
- Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig, Germany
| | - Bernhard Sattler
- Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig, Germany
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Gaubert V, Gidik H, Koncar V. Proposal of a Lab Bench for the Unobtrusive Monitoring of the Bladder Fullness with Bioimpedance Measurements. SENSORS (BASEL, SWITZERLAND) 2020; 20:E3980. [PMID: 32709078 PMCID: PMC7412207 DOI: 10.3390/s20143980] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/08/2020] [Accepted: 07/15/2020] [Indexed: 11/16/2022]
Abstract
(1) Background: millions of people, from children to the elderly, suffer from bladder dysfunctions all over the world. Monitoring bladder fullness with appropriate miniaturized textile devices can improve, significantly, their daily life quality, or even cure them. Amongst the existing bladder sensing technologies, bioimpedance spectroscopy seems to be the most appropriate one to be integrated into textiles. (2) Methods: to assess the feasibility of monitoring the bladder fullness with textile-based bioimpedance spectroscopy; an innovative lab-bench has been designed and fabricated. As a step towards obtaining a more realistic pelvic phantom, ex vivo pig's bladder and skin were used. The electrical properties of the fabricated pelvic phantom have been compared to those of two individuals with tetrapolar impedance measurements. The measurements' reproducibility on the lab bench has been evaluated and discussed. Moreover, its suitability for the continuous monitoring of the bladder filling has been investigated. (3) Results: although the pelvic phantom failed in reproducing the frequency-dependent electrical properties of human tissues, it was found to be suitable at 5 kHz to record bladder volume change. The resistance variations recorded are proportional to the conductivity of the liquid filling the bladder. A 350 mL filling with artificial urine corresponds to a decrease in resistance of 7.2%, which was found to be in the same range as in humans. (4) Conclusions: based on that resistance variation; the instantaneous bladder fullness can be extrapolated. The presented lab-bench will be used to evaluate the ability of textiles electrodes to unobtrusively monitor the bladder volume.
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Affiliation(s)
- Valentin Gaubert
- GEnie et Matériaux TEXtiles (GEMTEX) Laboratory, École Nationale Supérieure des Arts et Industries Textiles (ENSAIT), F-59100 Roubaix, France; (H.G.); (V.K.)
- Hautes Etudes Ingénieur (HEI)—YNCREA, University of Lille, F-59650 Villeneuve d’Ascq, France
| | - Hayriye Gidik
- GEnie et Matériaux TEXtiles (GEMTEX) Laboratory, École Nationale Supérieure des Arts et Industries Textiles (ENSAIT), F-59100 Roubaix, France; (H.G.); (V.K.)
- Hautes Etudes Ingénieur (HEI)—YNCREA, University of Lille, F-59650 Villeneuve d’Ascq, France
| | - Vladan Koncar
- GEnie et Matériaux TEXtiles (GEMTEX) Laboratory, École Nationale Supérieure des Arts et Industries Textiles (ENSAIT), F-59100 Roubaix, France; (H.G.); (V.K.)
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Aldosary G, Tse T, Arnaout A, Caudrelier JM, Czyrnyj C, Romain R, McLean L, Foottit C, Belec J, Vandervoort E. Radiological, dosimetric and mechanical properties of a deformable breast phantom for radiation therapy and surgical applications. Biomed Phys Eng Express 2020; 6:035028. [PMID: 33438673 DOI: 10.1088/2057-1976/ab834a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The displacement of tumor bed walls during oncoplastic breast surgery (OBS) decreases the accuracy of using surgical clips as the sole surrogate for tumor bed location. This highlights the need for better communication of OBS techniques to radiation oncologists. To facilitate OBS practice and investigate clip placement reliability, a realistic silicone-based breast phantom was constructed with components emulating a breast parenchyma, epidermis, areola, nipple, chest wall, and a tumor. OBS was performed on the phantom and surgical clips were placed to mark the tumor bed. The phantom was imaged with CT, MRI, and ultrasound (US). The parenchyma's signal-to-noise ratio (SNR) and clips to parenchyma's contrast-to-noise ratio (CNR) were measured. The phantom's CT Hounsfield Unit (HU), relative electron density (RED), and mass density were determined. 6 and 10 MV photon beam attenuation measurements were performed in phantom material. The Young's Modulus and ultimate tensile strength (UTS) of the phantom parenchyma and epidermis were measured. Results showed that the breast phantom components were visible on all imaging modalities with adequate SNR and CNR. The phantom's HU is 130 ± 10. The RED is 0.983. Its mass density is 1.01 ± 0.01 g cm-3. Photon attenuation measurements in phantom material were within 1% of those in water. The Young's Moduli were 13.4 ± 4.2 kPa (mechanical) and 30.2 ± 4.1 kPa (US elastography) for the phantom parenchyma. The UTS' were 0.05 ± 0.01 MPa (parenchyma) and 0.23 ± 0.12 MPa (epidermis). We conclude that the phantom's imaging characteristics resemble a fibroglandular breast's and allow clear visualization of high-density markers used in radiation therapy. The phantom material is suitable for dose measurements in MV photon beams. Mechanical results confirmed the phantom's similarity to breast tissue. The phantom enables investigation of surgical clip displacements pre- and post-OBS, and is useful for radiation therapy quality assurance applications.
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Affiliation(s)
- Ghada Aldosary
- Department of Physics, Carleton University, Ottawa, Ontario, Canada. Radiation Oncology Section, Department of Oncology, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia
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Nanodiamond phantoms mimicking human liver: perspective to calibration of T1 relaxation time in magnetic resonance imaging. Sci Rep 2020; 10:6446. [PMID: 32296116 PMCID: PMC7160200 DOI: 10.1038/s41598-020-63581-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 03/30/2020] [Indexed: 11/21/2022] Open
Abstract
Phantoms of biological tissues are materials that mimic the properties of real tissues. This study shows the development of phantoms with nanodiamond particles for calibration of T1 relaxation time in magnetic resonance imaging. Magnetic resonance imaging (MRI) is a commonly used and non-invasive method of detecting pathological changes inside the human body. Nevertheless, before a new MRI device is approved for use, it is necessary to calibrate it properly and to check its technical parameters. In this article, we present phantoms of tissue with diamond nanoparticles dedicated to magnetic resonance calibration. The method of producing phantoms has been described. As a result of our research, we obtained phantoms that were characterized by the relaxation time T1 the same as the relaxation time of the human tissue T1 = 810.5 ms. Furthermore, the use of diamond nanoparticles in phantoms allowed us to tune the T1 value of the phantoms which open the way to elaborated phantoms of other tissues in the future.
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Ntombela L, Adeleye B, Chetty N. Low-cost fabrication of optical tissue phantoms for use in biomedical imaging. Heliyon 2020; 6:e03602. [PMID: 32258463 PMCID: PMC7096755 DOI: 10.1016/j.heliyon.2020.e03602] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/28/2019] [Accepted: 03/11/2020] [Indexed: 12/21/2022] Open
Abstract
The rapid development of new optical imaging techniques is dependent on the availability of low-cost and easily reproducible standards for technique validation. This work describes a low-cost fabrication process of an agar gel-based phantom that may accurately simulate the optical properties of different human tissues at 532 and 630nm wavelengths. It was designed to match the optical properties of the brain, bladder wall, and lung tissues. These low-cost phantoms use agar powders dissolved in water as the bulk matrix. The latter is loaded with varying amounts of India ink, and aluminium oxide Al2O3 particles for optical absorption and scattering targets. The optical properties (absorption and scattering coefficients), the primary design factor and critical parameters of these phantoms were deduced from measurements of the total attenuation coefficients( μ t ) . It is anticipated that the constructed tissue phantoms have the potential to be used as a reference standard since it's possible to preserve the optical properties in a period exceeding two years, under ideal storage conditions.
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Affiliation(s)
| | | | - Naven Chetty
- School of Chemistry and Physics, University of KwaZulu–Natal, Private Bag X01, Scottsville, 3209, South Africa
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Unterhorst K, Gerwinn H, Pohl A, Kärgel C, Massau C, Ristow I, Kneer J, Amelung T, Walter H, Beier K, Walter M, Schiffer B, Kruger THC, Stirn A, Ponseti J. An Exploratory Study on the Central Nervous Correlates of Sexual Excitation and Sexual Inhibition. JOURNAL OF SEX RESEARCH 2020; 57:397-408. [PMID: 30489159 DOI: 10.1080/00224499.2018.1539462] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The Sexual Inhibition/Sexual Excitation Scales (SIS/SES) measure sexual excitation and sexual inhibition proneness. We used SIS and SES scores of 62 heterosexual teleiophilic men (Mage 34.3, SD = 9.9) to predict brain activation levels during the presentation of male and female visual sexual stimuli in a magnetic resonance imaging (MRI) scanner. Statistical analyses revealed significant correlations. SES and SIS1 scores were positively associated with brain activation in various brain regions during the presentation of both male and female stimuli. SIS2 turned out to be a weaker predictor of brain activation, still revealing one significant correlation in the right lateral orbitofrontal cortex. Significant regions for SES and SIS1 were, among others, primary and supplementary motor areas, the caudate nucleus, the dorsal anterior cingulate cortex, anterior insula, and prefrontal areas. Our study can be seen as an exploratory investigation of SIS and SES with means of functional brain imaging. The results provide a promising contribution to the assertion of neurophysiological systems of sexual inhibition and excitation proneness.
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Affiliation(s)
- K Unterhorst
- Institute for Sexual Medicine and Forensic Psychiatry and Psychotherapy, Center for Integrative Psychiatry
| | - H Gerwinn
- Institute for Sexual Medicine and Forensic Psychiatry and Psychotherapy, Center for Integrative Psychiatry
| | - A Pohl
- Institute for Sexual Medicine and Forensic Psychiatry and Psychotherapy, Center for Integrative Psychiatry
| | - C Kärgel
- Division of Forensic Psychiatry, Department of Psychiatry, Psychotherapy, and Preventive Medicine, LWL-University Hospital Bochum
- Institute of Forensic Psychiatry, University of Duisburg-Essen
| | - C Massau
- Division of Forensic Psychiatry, Department of Psychiatry, Psychotherapy, and Preventive Medicine, LWL-University Hospital Bochum
- Institute of Forensic Psychiatry, University of Duisburg-Essen
| | - I Ristow
- Clinical Affective Neuroimaging Laboratory, Otto von Guericke University Magdeburg
- Department of Behavioral Neurology, Leibniz Institute for Neurobiology
| | - J Kneer
- Division of Clinical Psychology and Sexual Medicine, Department of Clinical Psychiatry, Social Psychiatry, and Psychotherapy, Hannover Medical School
| | - T Amelung
- Institute of Sexology and Sexual Medicine, Charité-Universitätsmedizin Berlin
| | - H Walter
- Division of Mind and Brain Research, Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin
| | - K Beier
- Institute of Sexology and Sexual Medicine, Charité-Universitätsmedizin Berlin
| | - M Walter
- Clinical Affective Neuroimaging Laboratory, Otto von Guericke University Magdeburg
- Department of Behavioral Neurology, Leibniz Institute for Neurobiology
- Department of Psychiatry, Eberhard Karls University of Tübingen
| | - B Schiffer
- Division of Forensic Psychiatry, Department of Psychiatry, Psychotherapy, and Preventive Medicine, LWL-University Hospital Bochum
- Institute of Forensic Psychiatry, University of Duisburg-Essen
| | - T H C Kruger
- Division of Clinical Psychology and Sexual Medicine, Department of Clinical Psychiatry, Social Psychiatry, and Psychotherapy, Hannover Medical School
| | - A Stirn
- Institute for Sexual Medicine and Forensic Psychiatry and Psychotherapy, Center for Integrative Psychiatry
| | - J Ponseti
- Institute for Sexual Medicine and Forensic Psychiatry and Psychotherapy, Center for Integrative Psychiatry
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Bianchini L, Botta F, Origgi D, Rizzo S, Mariani M, Summers P, García-Polo P, Cremonesi M, Lascialfari A. PETER PHAN: An MRI phantom for the optimisation of radiomic studies of the female pelvis. Phys Med 2020; 71:71-81. [PMID: 32092688 DOI: 10.1016/j.ejmp.2020.02.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 01/29/2020] [Accepted: 02/04/2020] [Indexed: 01/26/2023] Open
Abstract
PURPOSE To develop a phantom for methodological radiomic investigation on Magnetic Resonance (MR) images of female patients affected by pelvic cancer. METHODS A pelvis-shaped container was filled with a MnCl2 solution reproducing the relaxation times (T1, T2) of muscle surrounding pelvic malignancies. Inserts simulating multi-textured lesions were embedded in the phantom. The relaxation times of muscle and tumour were measured on an MR scanner on healthy volunteers and patients; T1 and T2 of MnCl2 solutions were evaluated with a relaxometer to find the concentrations providing a match to in vivo relaxation times. Radiomic features were extracted from the phantom inserts and the patients' lesions. Their repeatability was assessed by multiple measurements. RESULTS Muscle T1 and T2 were 1128 (806-1378) and 51 (40-65) ms, respectively. The phantom reproduced in vivo values within 13% (T1) and 12% (T2). T1 and T2 of tumour tissue were 1637 (1396-2121) and 94 (79-101) ms, respectively. The phantom insert best mimicking the tumour agreed within 7% (T1) and 24% (T2) with in vivo values. Out of 1034 features, 75% (95%) had interclass correlation coefficient greater than 0.9 on T1 (T2)-weighted images, reducing to 33% (25%) if the phantom was repositioned. The most repeatable features on phantom showed values in agreement with the features extracted from patients' lesions. CONCLUSIONS We developed an MR phantom with inserts mimicking both relaxation times and texture of pelvic tumours. As exemplified with repeatability assessment, such phantom is useful to investigate features robustness and optimise the radiomic workflow on pelvic MR images.
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Affiliation(s)
- Linda Bianchini
- Department of Physics and INSTM RU, Università degli Studi di Milano, Italy.
| | - Francesca Botta
- Medical Physics Unit, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Daniela Origgi
- Medical Physics Unit, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Stefania Rizzo
- Clinica di Radiologia EOC, Istituto di Imaging della Svizzera Italiana, Sede Ospedale Regionale di Lugano, Switzerland
| | - Manuel Mariani
- Department of Physics and INSTM RU, Università degli Studi di Pavia, Italy
| | - Paul Summers
- Division of Radiology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Pablo García-Polo
- Southern Europe Global Research Organization, GE Healthcare, Madrid, Spain
| | - Marta Cremonesi
- Radiation Research Unit, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Alessandro Lascialfari
- Department of Physics and INSTM RU, Università degli Studi di Milano, Italy; Department of Physics and INSTM RU, Università degli Studi di Pavia, Italy
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Schlink BR, Ferris DP. A Lower Limb Phantom for Simulation and Assessment of Electromyography Technology. IEEE Trans Neural Syst Rehabil Eng 2019; 27:2378-2385. [DOI: 10.1109/tnsre.2019.2944297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Qin XY, Liu XX, Li ZY, Guo LY, Zheng ZZ, Guan HT, Song L, Zou YH, Fan TY. MRI Detectable Polymer Microspheres Embedded With Magnetic Ferrite Nanoclusters For Embolization: In Vitro And In Vivo Evaluation. Int J Nanomedicine 2019; 14:8989-9006. [PMID: 31819414 PMCID: PMC6873973 DOI: 10.2147/ijn.s209603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 09/25/2019] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE The objective of this study was to develop magnetic embolic microspheres that could be visualized by clinical magnetic resonance imaging (MRI) scanners aiming to improve the efficiency and safety of embolotherapy. METHODS AND DISCUSSION Magnetic ferrite nanoclusters (FNs) were synthesized with microwave-assisted solvothermal method, and their morphology, particle size, crystalline structure, magnetic properties as well as T2 relaxivity were characterized to confirm the feasibility of FNs as an MRI probe. Magnetic polymer microspheres (FNMs) were then produced by inverse suspension polymerization with FNs embedded inside. The physicochemical and mechanical properties (including morphology, particle size, infrared spectra, elasticity, etc.) of FNMs were investigated, and the magnetic properties and MRI detectable properties of FNMs were also assayed by vibrating sample magnetometer and MRI scanners. Favorable biocompatibility and long-term MRI detectability of FNMs were then studied in mice by subcutaneous injection. FNMs were further used to embolize rabbits' kidneys to evaluate the embolic property and detectability by MRI. CONCLUSION FNMs could serve as a promising MRI-visualized embolic material for embolotherapy in the future.
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Affiliation(s)
- Xiao-Ya Qin
- The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
- Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
| | - Xiao-Xin Liu
- The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
- Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
| | - Zi-Yuan Li
- The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
- Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
| | - Li-Ying Guo
- The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
- Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
| | - Zhuo-Zhao Zheng
- Department of Nuclear Medicine, Beijing Tsinghua Changgung Hospital, Beijing, People’s Republic of China
| | - Hai-Tao Guan
- Department of Interventional Radiology and Vascular Surgery, Peking University First Hospital, Beijing, People’s Republic of China
| | - Li Song
- Department of Interventional Radiology and Vascular Surgery, Peking University First Hospital, Beijing, People’s Republic of China
| | - Ying-Hua Zou
- Department of Interventional Radiology and Vascular Surgery, Peking University First Hospital, Beijing, People’s Republic of China
| | - Tian-Yuan Fan
- The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
- Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
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Zada MH, Goldberg SN, Nissenbaum Y, Domb AJ, Ben-David E. Injectable Biodegradable Multimodal Mammography Marker. ACS APPLIED BIO MATERIALS 2019; 2:5069-5076. [PMID: 35021505 DOI: 10.1021/acsabm.9b00749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Introducing temporary markers for imaging studies is an idea, which in the proper clinical settings can be advantageous for patient compliance and in selected cases where a permanent marker is nondesirable. Hence, we developed injectable marker formulation using a biodegradable "pasty polymer" of poly(ricinoleic acid-co-sebacic acid) (PSA:RA) containing iodixanol and iron oxide as contrast agents that can serve as a visual marker for the region suspected to have tumor growth. The goal of this work is to noninvasively evaluate the visibility, shape, and degradation of the injectable PSA:RA formulation using magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound (US). Prescreening of the marker formulation was performed under MRI and CT scanning using agar gel phantom models with poly(l-lactide-co-ε-caprolactone) (PCL:LA) solid inserts (clips) that contained varying combinations of the contrast agents. The contrast agent combination with the PCL:LA clip that had the best visibility in both MRI and CT was selected and additionally tested as in PSA:RA formulation. Further, we evaluated the PSA:RA marker placement in bovine liver and poultry muscles. The PSA:RA formulation is predictable with good MRI, CT, and US visibility and shows no in vivo systemic toxicity symptoms when implanted subcutaneously in mice. Further, the advantage of PSA:RA formulation is its undefined shape and ease of injecting through a small gauge needle, making it possible to reach into the regions of the body.
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Affiliation(s)
- Moran Haim Zada
- Institute of Drug Research, School of Pharmacy-Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - S Nahum Goldberg
- Department of Radiology, Hadassah Medical Center, Jerusalem 91999, Israel
| | | | - Abraham J Domb
- Institute of Drug Research, School of Pharmacy-Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Eliel Ben-David
- Department of Radiology, Shaare Zedek Medical Center, Jerusalem 91031, Israel
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Eresen A, Hafsa NE, Alic L, Birch SM, Griffin JF, Kornegay JN, Ji JX. Muscle percentage index as a marker of disease severity in golden retriever muscular dystrophy. Muscle Nerve 2019; 60:621-628. [PMID: 31397906 DOI: 10.1002/mus.26657] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Golden retriever muscular dystrophy (GRMD) is a spontaneous X-linked canine model of Duchenne muscular dystrophy that resembles the human condition. Muscle percentage index (MPI) is proposed as an imaging biomarker of disease severity in GRMD. METHODS To assess MPI, we used MRI data acquired from nine GRMD samples using a 4.7 T small-bore scanner. A machine learning approach was used with eight raw quantitative mapping of MRI data images (T1m, T2m, two Dixon maps, and four diffusion tensor imaging maps), three types of texture descriptors (local binary pattern, gray-level co-occurrence matrix, gray-level run-length matrix), and a gradient descriptor (histogram of oriented gradients). RESULTS The confusion matrix, averaged over all samples, showed 93.5% of muscle pixels classified correctly. The classification, optimized in a leave-one-out cross-validation, provided an average accuracy of 80% with a discrepancy in overestimation for young (8%) and old (20%) dogs. DISCUSSION MPI could be useful for quantifying GRMD severity, but careful interpretation is needed for severe cases.
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Affiliation(s)
- Aydin Eresen
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas
| | - Noor E Hafsa
- Department of Electrical and Computer Engineering, Texas A&M University, Doha, Qatar
| | - Lejla Alic
- Department of Electrical and Computer Engineering, Texas A&M University, Doha, Qatar.,Magnetic Detection & Imaging Group, Faculty of Science & Technology, University of Twente, Enschede, The Netherlands
| | - Sharla M Birch
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
| | - John F Griffin
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Joe N Kornegay
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Jim X Ji
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas.,Department of Electrical and Computer Engineering, Texas A&M University, Doha, Qatar
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Arteaga-Marrero N, Villa E, González-Fernández J, Martín Y, Ruiz-Alzola J. Polyvinyl alcohol cryogel phantoms of biological tissues for wideband operation at microwave frequencies. PLoS One 2019; 14:e0219997. [PMID: 31344092 PMCID: PMC6657873 DOI: 10.1371/journal.pone.0219997] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 07/05/2019] [Indexed: 11/18/2022] Open
Abstract
The aim of this work is to provide a methodology to model the dielectric properties of human tissues based on phantoms prepared with an aqueous solution, in a semi-solid form, by using off-the-shelf components. Polyvinyl alcohol cryogel (PVA-C) has been employed as a novel gelling agent in the fabrication of phantoms for microwave applications in a wide frequency range, from 500 MHz to 20 GHz. Agar-based and deionized water phantoms have also been manufactured for comparison purposes. Mathematical models dependent on frequency and sucrose concentration are proposed to obtain the complex permittivity of the desired mimicked tissues. These models have been validated in the referred bandwidth showing a good agreement to experimental data for different sucrose concentrations. The PVA-C model provides a great performance as compared to agar, increasing the shelf-life of the phantoms and improving their consistency for contact-required devices. In addition, the feasibility of fabricating a multilayer phantom has been demonstrated with a two-layer phantom that exhibits a clear interface between each layer and its properties. Thus, the use of PVA-C extends the option for producing complex multilayer and multimodal phantoms.
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Affiliation(s)
- Natalia Arteaga-Marrero
- IACTec Medical Technology Group, Instituto de Astrofísica de Canarias (IAC), La Laguna, Santa Cruz de Tenerife, Spain
| | - Enrique Villa
- IACTec Medical Technology Group, Instituto de Astrofísica de Canarias (IAC), La Laguna, Santa Cruz de Tenerife, Spain
| | - Javier González-Fernández
- Departamento de Ingeniería Biomédica. Instituto Tecnológico de Canarias (ITC), Santa Cruz de Tenerife, Santa Cruz de Tenerife, Spain
| | - Yolanda Martín
- IACTec Medical Technology Group, Instituto de Astrofísica de Canarias (IAC), La Laguna, Santa Cruz de Tenerife, Spain
| | - Juan Ruiz-Alzola
- IACTec Medical Technology Group, Instituto de Astrofísica de Canarias (IAC), La Laguna, Santa Cruz de Tenerife, Spain
- Departamento de Señales y Comunicaciones. Instituto Universitario de Investigación Biomédica y Sanitaria (IUIBS). Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Las Palmas, Spain
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Savin CL, Tiron C, Carasevici E, Stan CS, Ibanescu SA, Simionescu BC, Peptu CA. Entrapment of N-Hydroxyphthalimide Carbon Dots in Different Topical Gel Formulations: New Composites with Anticancer Activity. Pharmaceutics 2019; 11:pharmaceutics11070303. [PMID: 31266139 PMCID: PMC6680570 DOI: 10.3390/pharmaceutics11070303] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/21/2019] [Accepted: 06/23/2019] [Indexed: 01/02/2023] Open
Abstract
In the present study, the antitumoral potential of three gel formulations loaded with carbon dots prepared from N-hydroxyphthalimide (CD-NHF) was examined and the influence of the gels on two types of skin melanoma cell lines and two types of breast cancer cell lines in 2D (cultured cells in normal plastic plates) and 3D (Matrigel) models was investigated. Antitumoral gels based on sodium alginate (AS), carboxymethyl cellulose (CMC), and the carbomer Ultrez 10 (CARB) loaded with CD-NHF were developed according to an adapted method reported by Hellerbach. Viscoelastic properties of CD-NHF-loaded gels were analyzed by rheological analysis. Also, for both CD-NHF and CD-NHF-loaded gels, the fluorescence properties were analyzed. Cell proliferation, apoptosis, and mitochondrial activity were analyzed according to basic methods used to evaluate modulatory activities of putative anticancer agents, which include reference cancer cell line culture assays in both classic 2D and 3D cultures. Using the rheological measurements, the mechanical properties of gel formulations were analyzed; all samples presented gel-like rheological characteristics. The presence of CD-NHF within the gels induces a slight decrease of the dynamic moduli, indicating a flexible gel structure. The fluorescence investigations showed that for the gel-loaded CD-NHF, the most intense emission peak was located at 370 nm (upon excitation at 330 nm). 3D cell cultures displayed visibly larger structure of tumor cells with less active phenotype appearance. The in vitro results for tested CD-NHF-loaded gel formulations revealed that the new composites are able to affect the number, size, and cellular organization of spheroids and impact individual tumor cell ability to proliferate and aggregate in spheroids.
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Affiliation(s)
- Corina-Lenuta Savin
- Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection, "Gheorghe Asachi" Technical University of Iasi, 71, Prof., Dr. Docent Dimitrie Mangeron Street, 700050 Iasi, Romania
| | - Crina Tiron
- Regional Institute of Oncology, 2-4, General Henri Mathias Berthelot Street, 700483 Iasi, Romania.
| | - Eugen Carasevici
- Regional Institute of Oncology, 2-4, General Henri Mathias Berthelot Street, 700483 Iasi, Romania
| | - Corneliu S Stan
- Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection, "Gheorghe Asachi" Technical University of Iasi, 71, Prof., Dr. Docent Dimitrie Mangeron Street, 700050 Iasi, Romania
| | - Sorin Alexandru Ibanescu
- "Petru Poni" Institute of Macromolecular Chemistry, 41A Aleea Grigore Ghica Vodă street, 700487 Iasi, Romania
| | - Bogdan C Simionescu
- Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection, "Gheorghe Asachi" Technical University of Iasi, 71, Prof., Dr. Docent Dimitrie Mangeron Street, 700050 Iasi, Romania
- "Petru Poni" Institute of Macromolecular Chemistry, 41A Aleea Grigore Ghica Vodă street, 700487 Iasi, Romania
| | - Catalina A Peptu
- Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection, "Gheorghe Asachi" Technical University of Iasi, 71, Prof., Dr. Docent Dimitrie Mangeron Street, 700050 Iasi, Romania.
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Murata S, Tachibana Y, Murata K, Kamagata K, Hori M, Andica C, Suzuki M, Wada A, Kumamaru K, Hagiwara A, Irie R, Sato S, Hamasaki N, Fukunaga I, Hoshito H, Aoki S. Comparison of magnetization transfer contrast of conventional and simultaneous multislice turbo spin echo acquisitions focusing on excitation time interval. Jpn J Radiol 2019; 37:579-589. [PMID: 31230186 DOI: 10.1007/s11604-019-00848-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 06/14/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE Image contrast differs between conventional multislice turbo spin echo (conventional TSE) and multiband turbo spin echo (SMS-TSE). Difference in time interval between excitations for adjacent slices (SETI) might cause this difference. This study aimed to evaluate the influence of SETI on MT effect for conventional TSE and compare conventional TSE with SMS-TSE in this respect. MATERIALS AND METHODS Three different agar concentration phantoms were scanned with conventional TSE by adjusting SETI and TR. Signal change for different SETI was evaluated using Pearson's correlation analysis. SMS-TSE was acquired by changing TR similarly. Three human volunteers were scanned with similar settings to evaluate reproducibility of the phantom results in human brain. RESULTS In conventional TSE, shorter SETI induced larger signal reduction. Longer TR and higher agar concentration emphasized this characteristic. Significant linear correlation (P < 0.05) was found in the major cases. The SMS-TSE signal intensity in each TR and phantom was smaller than the assumable levels in conventional TSE when the slices were simultaneously excited. Similar characteristic was observed in human brain. CONCLUSION Shorter SETI results in larger MT effect in conventional TSE. The contrast change in SMS-TSE was larger than the supposable level from simultaneous excitation, which needs consideration in clinics.
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Affiliation(s)
- Syo Murata
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yasuhiko Tachibana
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. .,Applied MRI Research, Department of Molecular Imaging and Theranostics, NIRS, QST, Chiba, Japan.
| | | | - Koji Kamagata
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masaaki Hori
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Christina Andica
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Michimasa Suzuki
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Akihiko Wada
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kanako Kumamaru
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Akifumi Hagiwara
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Ryusuke Irie
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shuji Sato
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Nozomi Hamasaki
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Issei Fukunaga
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Haruyoshi Hoshito
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Shigeki Aoki
- Department of Radiology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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Abstract
The feasibility of using hydrogels as a water bolus during hyperthermia treatment was assessed. Three types of gels, high methoxyl (HM) pectin/alginate, xanthan/locust bean gum (LBG) and xanthan/LBG/agarose were evaluated based on their dielectric, rheological and mechanical properties. The most suitable, xanthan/LBG/agarose gel was further used as a water bolus in a hyperthermia array applicator. The gels composed of polysaccharides carrying low charge displayed dielectric properties close to those of water, while the dielectric properties of HM pectin/alginate gel was deemed unsuitable for the current application. The mechanical examination shows that the xanthan/LBG gel has a non-brittle behaviour at room temperature, in contrast to the agarose gel. The moduli of the xanthan/LBG gel weaken however considerably between the temperature range of 40 °C and 50 °C, reducing its potential to be used as water bolus. The ternary system of xanthan/LBG/agarose had advantageous behaviour as it was dominated by the thermal hysteresis typical of agarose upon temperature increase, but governed by the typical non-brittle behaviour of the xanthan/LBG at low temperatures. The final evaluation within the hyperthermia applicator showed excellent signal transmission from the antennas. The agarose/xanthan/LBG gel reduced the scattering of electromagnetic waves, enabled a tight closure between the body and the antennas, and offered a less bulky solution than the currently used water-filled plastic bags. The results presented here open up a new application area for hydrogels in improving heat delivery during hyperthermia treatment and other near-field microwave applications.
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Affiliation(s)
- Hana Dobšíček Trefná
- Department of Electrical Engineering, Chalmers University of Technology, Göteborg, Sweden
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Brzozowski P, Penev KI, Martinez FM, Scholl TJ, Mequanint K. Gellan gum-based gels with tunable relaxation properties for MRI phantoms. Magn Reson Imaging 2019; 57:40-49. [DOI: 10.1016/j.mri.2018.10.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/26/2018] [Accepted: 10/27/2018] [Indexed: 11/16/2022]
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de Souza EM, Costa ET, Castellano G. Investigation of anisotropic fishing line-based phantom as tool in quality control of diffusion tensor imaging. Radiol Phys Technol 2019; 12:161-171. [PMID: 30877555 DOI: 10.1007/s12194-019-00507-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 12/14/2022]
Abstract
This work proposes a low-cost, fishing line-based phantom for quality control of diffusion tensor imaging (DTI). The device was applied to investigate the relationship between DTI indexes (DTIi) and imaging acquisition parameters. A Dyneema® fishing line phantom was built with fiber bundles of different thicknesses. DTI acquisitions were performed in a 3T magnetic resonance imaging scanner using an 8-channel and a 32-channel head coil. For each coil, the following acquisition parameters were changed, one at a time: diffusion sensitivity factor (b value), echo time, sensitivity encoding, voxel size, number of signal averages, and number of diffusion gradient directions (NDGD). DTIi including fractional anisotropy, relative anisotropy (RA), linear anisotropy (CL), and planar anisotropy (CP) were calculated for each image; the data were analyzed using the coefficient of variation (CV) and distributions of DTIi values. The 32-channel head coil presented higher CV values for the DTIi RA, CL, and CP when voxel size was changed. Using the phantom, dependences between diffusion-related parameters (b value and NDGD) and DTIi were also observed; the majority of these were for the smaller thickness fiber bundles. The device proved to be useful for the verification of the DTI performance over time.
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Affiliation(s)
- Edna Marina de Souza
- Biomedical Engineering Center, University of Campinas (UNICAMP), 163 Alexander Fleming St, Cidade Universitária, Campinas, SP, 13083 881, Brazil. .,Biomedical Engineering Department, School of Electrical and Computer Engineering, University of Campinas (UNICAMP), Campinas, Brazil. .,Neurophysics Group, Gleb Wataghin Physics Institute, University of Campinas (UNICAMP), 777 Sergio Buarque de Holanda St, University City, Campinas, SP, 13083 859, Brazil. .,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, Brazil.
| | - Eduardo Tavares Costa
- Biomedical Engineering Center, University of Campinas (UNICAMP), 163 Alexander Fleming St, Cidade Universitária, Campinas, SP, 13083 881, Brazil.,Biomedical Engineering Department, School of Electrical and Computer Engineering, University of Campinas (UNICAMP), Campinas, Brazil
| | - Gabriela Castellano
- Neurophysics Group, Gleb Wataghin Physics Institute, University of Campinas (UNICAMP), 777 Sergio Buarque de Holanda St, University City, Campinas, SP, 13083 859, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, Brazil
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Ebel S, Hübner L, Köhler B, Kropf S, Preim B, Jung B, Grothoff M, Gutberlet M. Validation of two accelerated 4D flow MRI sequences at 3 T: a phantom study. Eur Radiol Exp 2019; 3:10. [PMID: 30806827 PMCID: PMC6391502 DOI: 10.1186/s41747-019-0089-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 02/01/2019] [Indexed: 12/15/2022] Open
Abstract
Background Four-dimensional (4D) flow magnetic resonance imaging (MRI) sequences with advanced parallel imaging have the potential to reduce scan time with equivalent image quality and accuracy compared with standard two-dimensional (2D) flow MRI. We compared 4D flow to standard 2D flow sequences using a constant and pulsatile flow phantom at 3 T. Methods Two accelerated 4D flow sequences (GRAPPA2 and k-t-GRAPPA5) were evaluated regarding the concordance of flow volumes, flow velocities, and reproducibility as well as dependency on measuring plane and velocity encoding (Venc). The calculated flow volumes and peak velocities of the phantom were used as reference standard. Flow analysis was performed using the custom-made software “Bloodline”. Results No significant differences in flow volume were found between the 2D, both 4D flow MRI sequences, and the pump reference (p = 0.994) or flow velocities (p = 0.998) in continuous and pulsatile flow. An excellent correlation (R = 0.99–1.0) with a reference standard and excellent reproducibility of measurements (R = 0.99) was achieved for all sequences. A Venc overestimated by up to two times had no impact on flow measurements. However, misaligned measuring planes led to an increasing underestimation of flow volume and mean velocity in 2D flow accuracy, while both 4D flow measurements were not affected. Scan time was significantly shorter for k-t-GRAPPA5 (1:54 ± 0:01 min, mean ± standard deviation) compared to GRAPPA2 (3:56 ± 0:02 min) (p = 0.002). Conclusions Both 4D flow sequences demonstrated equal agreement with 2D flow measurements, without impact of Venc overestimation and plane misalignment. The highly accelerated k-t-GRAPPA5 sequence yielded results similar to those of GRAPPA2.
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Affiliation(s)
- Sebastian Ebel
- Department of Diagnostic and Interventional Radiology, University of Leipzig - Heart Centre, Leipzig Strümpellstrasse 39, 04289, Leipzig, Germany.
| | - Lisa Hübner
- Department of Diagnostic and Interventional Radiology, University of Leipzig - Heart Centre, Leipzig Strümpellstrasse 39, 04289, Leipzig, Germany
| | - Benjamin Köhler
- Department of Simulations and Graphics, University of Magdeburg, Magdeburg, Germany
| | - Siegfried Kropf
- Institute for Biometrics and Medical Informatics, University of Magdeburg, Magdeburg, Germany
| | - Bernhard Preim
- Department of Simulations and Graphics, University of Magdeburg, Magdeburg, Germany
| | - Bernd Jung
- Department of Diagnostic, Interventional and Paediatric Radiology, University of Bern, Bern, Switzerland
| | - Matthias Grothoff
- Department of Diagnostic and Interventional Radiology, University of Leipzig - Heart Centre, Leipzig Strümpellstrasse 39, 04289, Leipzig, Germany
| | - Matthias Gutberlet
- Department of Diagnostic and Interventional Radiology, University of Leipzig - Heart Centre, Leipzig Strümpellstrasse 39, 04289, Leipzig, Germany
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Kobe A, Zadory M, Hamie QM, Froehlich JM, Klarhöfer M, Elsässer T, Pfammatter T, Guggenberger R. Development of an anthropomorphic spine phantom suitable for fusion of MR neurography with interventional flat-panel CT. Eur J Radiol 2019; 112:153-160. [PMID: 30777205 DOI: 10.1016/j.ejrad.2019.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 01/12/2019] [Accepted: 01/20/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE To design a spine phantom suitable for fusion of MR neurography (MRN) with interventional flat panel computed tomography (FPCT) images from tissue-equivalent agarose gels and artificial nerves in MRI, including material with equal attenuation to bone in computed tomography (CT). METHODS T1-/T2-relaxation times of target tissue were determined in vivo (n = 5) using MR mapping-techniques. Serial dilution of castor oil lipogels was performed ex vivo in order to define correct composition for tissue-equivalent relaxation times. Similarly, serial dilution series of calcium carbonate (CaCO3) and barium sulphate (BaSO4) in synthetic resin were used to adjust radiodensity of selected vertebral bodies (L1-L5) and sacrum in CT. Nerve tissue was simulated with agarose-impregnated polyethylene fibers. Spine phantom was assembled using respective components in anthropomorphic geometry. A fat-saturated, T2-weighted 3D SPACE STIR sequence was acquired for MRN and subsequently fused with an on-site FPCT scan of the phantom. RESULTS In vivo T1-/T2-values for fat tissue were found to be at 394 ± 16 ms and 161 ± 16 ms, corresponding to a castor oil concentration of 50%. Analogously, bone marrow-equivalent values were measured at 822 ± 21 ms and 67 ± 6 ms, simulated with 40% castor oil. Cortical bone-like radiodensity of 1'115 ± 80 HU was achieved for artificial bone with 30% CaCO3 and 1.5% BaSO4. Simulated nerves were successfully depicted in MRN and fused with FPCT, combining optimal contrasts for nerves and bones on-site. CONCLUSIONS The customized phantom showed analogous tissue contrasts to in vivo conditions in both MRN and FPCT, facilitating simulations of fusion-image guided spine interventions.
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Affiliation(s)
- Adrian Kobe
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland
| | | | - Qeumars M Hamie
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland
| | | | | | | | - Thomas Pfammatter
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland
| | - Roman Guggenberger
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
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Kneer J, Borchardt V, Kärgel C, Sinke C, Massau C, Tenbergen G, Ponseti J, Walter H, Beier KM, Schiffer B, Schiltz K, Walter M, Kruger THC. Diminished fronto-limbic functional connectivity in child sexual offenders. J Psychiatr Res 2019. [PMID: 29530321 DOI: 10.1016/j.jpsychires.2018.01.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Child sexual abuse and neglect have been related to an increased risk for the development of a wide range of behavioral, psychological, and sexual problems and increased rates of suicidal behavior. Contrary to the large amount of research focusing on the negative mental health consequences of child sexual abuse, very little is known about the characteristics of child sexual offenders and the neuronal underpinnings contributing to child sexual offending. METHODS AND SAMPLE This study investigates differences in resting state functional connectivity (rs-FC) between non-pedophilic child sexual offenders (N = 20; CSO-P) and matched healthy controls (N = 20; HC) using a seed-based approach. The focus of this investigation of rs-FC in CSO-P was put on prefrontal and limbic regions highly relevant for emotional and behavioral processing. RESULTS Results revealed a significant reduction of rs-FC between the right centromedial amygdala and the left dorsolateral prefrontal cortex in child sexual offenders compared to controls. CONCLUSION & RECOMMENDATIONS Given that, in the healthy brain, there is a strong top-down inhibitory control of prefrontal over limbic structures, these results suggest that diminished rs-FC between the amygdala and the dorsolateral prefrontal cortex and may foster sexual deviance and sexual offending. A profound understanding of these concepts should contribute to a better understanding of the occurrence of child sexual offending, as well as further development of more differentiated and effective interventions.
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Affiliation(s)
- Jonas Kneer
- Division of Clinical Psychology and Sexual Medicine, Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany
| | - Viola Borchardt
- Clinical Affective Neuroimaging Laboratory, Magdeburg, Germany; Leibniz Institute for Neurobiology, Department of Behavioral Neurology, Magdeburg, Germany
| | - Christian Kärgel
- LWL-University Hospital Bochum, Division of Forensic Psychiatry, Alexandrinenstr. 1-3, 44791 Bochum, Germany
| | - Christopher Sinke
- Division of Clinical Psychology and Sexual Medicine, Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany
| | - Claudia Massau
- LWL-University Hospital Bochum, Division of Forensic Psychiatry, Alexandrinenstr. 1-3, 44791 Bochum, Germany
| | - Gilian Tenbergen
- Department of Psychology, SUNY College at Oswego, Oswego, NY, USA
| | - Jorge Ponseti
- Institute of Sexual Medicine and Forensic Psychiatry and Psychotherapy, Kiel University, Medical School, Kiel, Germany
| | - Henrik Walter
- Division of Mind and Brain Research, Department of Psychiatry and Psychotherapy CCM, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Klaus M Beier
- Institute of Sexology and Sexual Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Boris Schiffer
- LWL-University Hospital Bochum, Division of Forensic Psychiatry, Alexandrinenstr. 1-3, 44791 Bochum, Germany
| | - Kolja Schiltz
- Department of Forensic Psychiatry, Psychiatric Hospital of the Ludwig-Maximilians-University, München, Germany; (j)Otto-von-Guericke-University Magdeburg, Department of Psychiatry, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Martin Walter
- Department of Psychiatry University of Tübingen Osianderstr. 24, 72076 Tübingen, Germany
| | - Tillmann H C Kruger
- Division of Clinical Psychology and Sexual Medicine, Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany
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Fieremans E, Lee HH. Physical and numerical phantoms for the validation of brain microstructural MRI: A cookbook. Neuroimage 2018; 182:39-61. [PMID: 29920376 PMCID: PMC6175674 DOI: 10.1016/j.neuroimage.2018.06.046] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 06/08/2018] [Accepted: 06/13/2018] [Indexed: 12/24/2022] Open
Abstract
Phantoms, both numerical (software) and physical (hardware), can serve as a gold standard for the validation of MRI methods probing the brain microstructure. This review aims to provide guidelines on how to build, implement, or choose the right phantom for a particular application, along with an overview of the current state-of-the-art of phantoms dedicated to study brain microstructure with MRI. For physical phantoms, we discuss the essential requirements and relevant characteristics of both the (NMR visible) liquid and (NMR invisible) phantom materials that induce relevant microstructural features detectable via MRI, based on diffusion, intra-voxel incoherent motion, magnetization transfer or magnetic susceptibility weighted contrast. In particular, for diffusion MRI, many useful phantoms have been proposed, ranging from simple liquids to advanced biomimetic phantoms consisting of hollow or plain microfibers and capillaries. For numerical phantoms, the focus is on Monte Carlo simulations of random walk, for which the basic principles, along with useful criteria to check and potential pitfalls are reviewed, in addition to a literature overview highlighting recent advances. While many phantoms exist already, the current review aims to stimulate further research in the field and to address remaining needs.
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Affiliation(s)
- Els Fieremans
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - Hong-Hsi Lee
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
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Integrity Assessment of a Hybrid DBS Probe that Enables Neurotransmitter Detection Simultaneously to Electrical Stimulation and Recording. MICROMACHINES 2018; 9:mi9100510. [PMID: 30424443 PMCID: PMC6215126 DOI: 10.3390/mi9100510] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/05/2018] [Accepted: 10/05/2018] [Indexed: 12/12/2022]
Abstract
Deep brain stimulation (DBS) is a successful medical therapy for many treatment resistant neuropsychiatric disorders such as movement disorders; e.g., Parkinson's disease, Tremor, and dystonia. Moreover, DBS is becoming more and more appealing for a rapidly growing number of patients with other neuropsychiatric diseases such as depression and obsessive compulsive disorder. In spite of the promising outcomes, the current clinical hardware used in DBS does not match the technological standards of other medical applications and as a result could possibly lead to side effects such as high energy consumption and others. By implementing more advanced DBS devices, in fact, many of these limitations could be overcome. For example, a higher channels count and smaller electrode sites could allow more focal and tailored stimulation. In addition, new materials, like carbon for example, could be incorporated into the probes to enable adaptive stimulation protocols by biosensing neurotransmitters in the brain. Updating the current clinical DBS technology adequately requires combining the most recent technological advances in the field of neural engineering. Here, a novel hybrid multimodal DBS probe with glassy carbon microelectrodes on a polyimide thin-film device assembled on a silicon rubber tubing is introduced. The glassy carbon interface enables neurotransmitter detection using fast scan cyclic voltammetry and electrophysiological recordings while simultaneously performing electrical stimulation. Additionally, the presented DBS technology shows no imaging artefacts in magnetic resonance imaging. Thus, we present a promising new tool that might lead to a better fundamental understanding of the underlying mechanism of DBS while simultaneously paving our way towards better treatments.
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Filippou V, Tsoumpas C. Recent advances on the development of phantoms using 3D printing for imaging with CT, MRI, PET, SPECT, and ultrasound. Med Phys 2018; 45. [PMID: 29933508 PMCID: PMC6849595 DOI: 10.1002/mp.13058] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/03/2018] [Accepted: 06/15/2018] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Printing technology, capable of producing three-dimensional (3D) objects, has evolved in recent years and provides potential for developing reproducible and sophisticated physical phantoms. 3D printing technology can help rapidly develop relatively low cost phantoms with appropriate complexities, which are useful in imaging or dosimetry measurements. The need for more realistic phantoms is emerging since imaging systems are now capable of acquiring multimodal and multiparametric data. This review addresses three main questions about the 3D printers currently in use, and their produced materials. The first question investigates whether the resolution of 3D printers is sufficient for existing imaging technologies. The second question explores if the materials of 3D-printed phantoms can produce realistic images representing various tissues and organs as taken by different imaging modalities such as computer tomography (CT), positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), ultrasound (US), and mammography. The emergence of multimodal imaging increases the need for phantoms that can be scanned using different imaging modalities. The third question probes the feasibility and easiness of "printing" radioactive or nonradioactive solutions during the printing process. METHODS A systematic review of medical imaging studies published after January 2013 is performed using strict inclusion criteria. The databases used were Scopus and Web of Knowledge with specific search terms. In total, 139 papers were identified; however, only 50 were classified as relevant for this paper. In this review, following an appropriate introduction and literature research strategy, all 50 articles are presented in detail. A summary of tables and example figures of the most recent advances in 3D printing for the purposes of phantoms across different imaging modalities are provided. RESULTS All 50 studies printed and scanned phantoms in either CT, PET, SPECT, mammography, MRI, and US-or a combination of those modalities. According to the literature, different parameters were evaluated depending on the imaging modality used. Almost all papers evaluated more than two parameters, with the most common being Hounsfield units, density, attenuation and speed of sound. CONCLUSIONS The development of this field is rapidly evolving and becoming more refined. There is potential to reach the ultimate goal of using 3D phantoms to get feedback on imaging scanners and reconstruction algorithms more regularly. Although the development of imaging phantoms is evident, there are still some limitations to address: One of which is printing accuracy, due to the printer properties. Another limitation is the materials available to print: There are not enough materials to mimic all the tissue properties. For example, one material can mimic one property-such as the density of real tissue-but not any other property, like speed of sound or attenuation.
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Affiliation(s)
- Valeria Filippou
- Institute of Medical and Biological EngineeringFaculty of Mechanical EngineeringUniversity of LeedsLeedsLS2 9JTWest YorkshireUK
| | - Charalampos Tsoumpas
- Department of Biomedical Imaging ScienceSchool of MedicineUniversity of LeedsLeedsLS2 9NLWest YorkshireUK
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Vogelbacher C, Möbius TW, Sommer J, Schuster V, Dannlowski U, Kircher T, Dempfle A, Jansen A, Bopp MH. The Marburg-Münster Affective Disorders Cohort Study (MACS): A quality assurance protocol for MR neuroimaging data. Neuroimage 2018; 172:450-460. [DOI: 10.1016/j.neuroimage.2018.01.079] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 01/26/2018] [Accepted: 01/30/2018] [Indexed: 12/14/2022] Open
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Ciui B, Martin A, Mishra RK, Brunetti B, Nakagawa T, Dawkins TJ, Lyu M, Cristea C, Sandulescu R, Wang J. Wearable Wireless Tyrosinase Bandage and Microneedle Sensors: Toward Melanoma Screening. Adv Healthc Mater 2018; 7:e1701264. [PMID: 29345430 DOI: 10.1002/adhm.201701264] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/27/2017] [Indexed: 02/01/2023]
Abstract
Wearable bendable bandage-based sensor and a minimally invasive microneedle biosensor are described toward rapid screening of skin melanoma. These wearable electrochemical sensors are capable of detecting the presence of the tyrosinase (TYR) enzyme cancer biomarker in the presence of its catechol substrate, immobilized on the transducer surface. In the presence of the surface TYR biomarker, the immobilized catechol is rapidly converted to benzoquinone that is detected amperometrically, with a current signal proportional to the TYR level. The flexible epidermal bandage sensor relies on printing stress-enduring inks which display good resiliency against mechanical deformations, whereas the hollow microneedle device is filled with catechol-coated carbon paste for assessing tissue TYR levels. The bandage sensor can thus be used directly on the skin whereas microneedle device can reach melanoma tissues under the skin. Both wearable sensors are interfaced to an ultralight flexible electronic board, which transmits data wirelessly to a mobile device. The analytical performance of the resulting bandage and microneedle sensing systems are evaluated using TYR-containing agarose phantom gel and porcine skin. The new integrated conformal portable sensing platforms hold considerable promise for decentralized melanoma screening, and can be extended to the screening of other key biomarkers in skin moles.
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Affiliation(s)
- Bianca Ciui
- Department of Nanoengineering, University of California, San Diego La Jolla, CA, 92093, USA
- Analytical Chemistry Department, UMF, Cluj-Napoca, 400349, Romania
| | - Aida Martin
- Department of Nanoengineering, University of California, San Diego La Jolla, CA, 92093, USA
| | - Rupesh K Mishra
- Department of Nanoengineering, University of California, San Diego La Jolla, CA, 92093, USA
| | - Barbara Brunetti
- Department of Nanoengineering, University of California, San Diego La Jolla, CA, 92093, USA
- DeFENS, University of Milan, Milan, I-20133, Italy
| | - Tatsuo Nakagawa
- Department of Nanoengineering, University of California, San Diego La Jolla, CA, 92093, USA
| | - Thomas J Dawkins
- Department of Nanoengineering, University of California, San Diego La Jolla, CA, 92093, USA
| | - Mengjia Lyu
- Department of Nanoengineering, University of California, San Diego La Jolla, CA, 92093, USA
| | - Cecilia Cristea
- Analytical Chemistry Department, UMF, Cluj-Napoca, 400349, Romania
| | | | - Joseph Wang
- Department of Nanoengineering, University of California, San Diego La Jolla, CA, 92093, USA
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Brink WM, Wu Z, Webb AG. A simple head-sized phantom for realistic static and radiofrequency characterization at high fields. Magn Reson Med 2018; 80:1738-1745. [PMID: 29498102 DOI: 10.1002/mrm.27153] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/12/2018] [Accepted: 02/05/2018] [Indexed: 12/28/2022]
Abstract
PURPOSE To demonstrate a simple head-sized phantom for realistic static and RF field characterization in high field systems. METHODS The head-sized phantom was composed of an ellipsoidal compartment and a spherical cavity to mimic the nasal cavity. The phantom was filled with an aqueous solution of polyvinylpyrrolidone (PVP), to mimic the average dielectric properties of brain tissue. The static and RF field distributions were characterized on a 7T MRI system and compared to in vivo measurements and simulations. MR thermometry was performed, and the results were compared to thermal simulations for RF validation purposes. RESULTS Accurate reproduction of both static and RF fields patterns observed in vivo was confirmed experimentally and was shown to be strongly affected by the inclusion of the spherical cavity. MR thermometry and transmit efficiency ( B1+) measurements were obtained in close agreement with simulations (peak values agreeing within 0.3 °C and 0.02 μT/√W) as well as fiber optic thermal probes (RMSE < 0.18 °C). CONCLUSIONS A simple head-sized phantom has been presented that produces B0 and B1+ nonuniformities similar to those encountered in the human head and allows for accurate MR thermometry measurements, making this a suitable reference phantom for RF validation and methodological development in high field MRI.
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Affiliation(s)
- Wyger M Brink
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Zhiyi Wu
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Andrew G Webb
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
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McDermott B, McGinley B, Krukiewicz K, Divilly B, Jones M, Biggs M, O’Halloran M, Porter E. Stable tissue-mimicking materials and an anatomically realistic, adjustable head phantom for electrical impedance tomography. Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/aa922d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wagner F, Laun FB, Kuder TA, Mlynarska A, Maier F, Faust J, Demberg K, Lindemann L, Rivkin B, Nagel AM, Ladd ME, Maier-Hein K, Bickelhaupt S, Bach M. Temperature and concentration calibration of aqueous polyvinylpyrrolidone (PVP) solutions for isotropic diffusion MRI phantoms. PLoS One 2017; 12:e0179276. [PMID: 28628638 PMCID: PMC5476261 DOI: 10.1371/journal.pone.0179276] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 05/27/2017] [Indexed: 12/12/2022] Open
Abstract
To use the "apparent diffusion coefficient" (Dapp) as a quantitative imaging parameter, well-suited test fluids are essential. In this study, the previously proposed aqueous solutions of polyvinylpyrrolidone (PVP) were examined and temperature calibrations were obtained. For example, at a temperature of 20°C, Dapp ranged from 1.594 (95% CI: 1.593, 1.595) μm2/ms to 0.3326 (95% CI: 0. 3304, 0.3348) μm2/ms for PVP-concentrations ranging from 10% (w/w) to 50% (w/w) using K30 polymer lengths. The temperature dependence of Dapp was found to be so strong that a negligence seems not advisable. The temperature dependence is descriptively modelled by an exponential function exp(c2 (T - 20°C)) and the determined c2 values are reported, which can be used for temperature calibration. For example, we find the value 0.02952 K-1 for 30% (w/w) PVP-concentration and K30 polymer length. In general, aqueous PVP solutions were found to be suitable to produce easily applicable and reliable Dapp-phantoms.
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Affiliation(s)
- Friedrich Wagner
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Frederik B. Laun
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Institute of Radiology, University Hospital Erlangen, Erlangen, Germany
| | - Tristan A. Kuder
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Anna Mlynarska
- Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Florian Maier
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jonas Faust
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kerstin Demberg
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Linus Lindemann
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Boris Rivkin
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin M. Nagel
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Institute of Radiology, University Hospital Erlangen, Erlangen, Germany
| | - Mark E. Ladd
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Klaus Maier-Hein
- Medical and Biological Informatics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Michael Bach
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Souza EMD, Costa ET, Castellano G. Phantoms for diffusion-weighted imaging and diffusion tensor imaging quality control: a review and new perspectives. ACTA ACUST UNITED AC 2017. [DOI: 10.1590/2446-4740.07816] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | | | - Gabriela Castellano
- University of Campinas, Brazil; Brazilian Institute of Neuroscience and Neurotechnology, Brazil
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