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Niendorf T, Gladytz T, Cantow K, Klein T, Tasbihi E, Velasquez Vides JR, Zhao K, Millward JM, Waiczies S, Seeliger E. MRI of kidney size matters. MAGMA (NEW YORK, N.Y.) 2024:10.1007/s10334-024-01168-5. [PMID: 38960988 DOI: 10.1007/s10334-024-01168-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/06/2024] [Accepted: 05/15/2024] [Indexed: 07/05/2024]
Abstract
OBJECTIVE To highlight progress and opportunities of measuring kidney size with MRI, and to inspire research into resolving the remaining methodological gaps and unanswered questions relating to kidney size assessment. MATERIALS AND METHODS This work is not a comprehensive review of the literature but highlights valuable recent developments of MRI of kidney size. RESULTS The links between renal (patho)physiology and kidney size are outlined. Common methodological approaches for MRI of kidney size are reviewed. Techniques tailored for renal segmentation and quantification of kidney size are discussed. Frontier applications of kidney size monitoring in preclinical models and human studies are reviewed. Future directions of MRI of kidney size are explored. CONCLUSION MRI of kidney size matters. It will facilitate a growing range of (pre)clinical applications, and provide a springboard for new insights into renal (patho)physiology. As kidney size can be easily obtained from already established renal MRI protocols without the need for additional scans, this measurement should always accompany diagnostic MRI exams. Reconciling global kidney size changes with alterations in the size of specific renal layers is an important topic for further research. Acute kidney size measurements alone cannot distinguish between changes induced by alterations in the blood or the tubular volume fractions-this distinction requires further research into cartography of the renal blood and the tubular volumes.
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Affiliation(s)
- Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany.
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.
| | - Thomas Gladytz
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Kathleen Cantow
- Institute of Translational Physiology, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Tobias Klein
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Digital Health-Machine Learning Research Group, Hasso Plattner Institute for Digital Engineering, University of Potsdam, Potsdam, Germany
| | - Ehsan Tasbihi
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jose Raul Velasquez Vides
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Institute for Medical Engineering, Otto Von Guericke University, Magdeburg, Germany
| | - Kaixuan Zhao
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jason M Millward
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sonia Waiczies
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Erdmann Seeliger
- Institute of Translational Physiology, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
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Wu C, Hormuth DA, Easley T, Pineda F, Karczmar GS, Yankeelov TE. Systematic evaluation of MRI-based characterization of tumor-associated vascular morphology and hemodynamics via a dynamic digital phantom. J Med Imaging (Bellingham) 2024; 11:024002. [PMID: 38463607 PMCID: PMC10921778 DOI: 10.1117/1.jmi.11.2.024002] [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: 06/06/2023] [Revised: 01/26/2024] [Accepted: 02/19/2024] [Indexed: 03/12/2024] Open
Abstract
Purpose Validation of quantitative imaging biomarkers is a challenging task, due to the difficulty in measuring the ground truth of the target biological process. A digital phantom-based framework is established to systematically validate the quantitative characterization of tumor-associated vascular morphology and hemodynamics based on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Approach A digital phantom is employed to provide a ground-truth vascular system within which 45 synthetic tumors are simulated. Morphological analysis is performed on high-spatial resolution DCE-MRI data (spatial/temporal resolution = 30 to 300 μ m / 60 s ) to determine the accuracy of locating the arterial inputs of tumor-associated vessels (TAVs). Hemodynamic analysis is then performed on the combination of high-spatial resolution and high-temporal resolution (spatial/temporal resolution = 60 to 300 μ m / 1 to 10 s) DCE-MRI data, determining the accuracy of estimating tumor-associated blood pressure, vascular extraction rate, interstitial pressure, and interstitial flow velocity. Results The observed effects of acquisition settings demonstrate that, when optimizing the DCE-MRI protocol for the morphological analysis, increasing the spatial resolution is helpful but not necessary, as the location and arterial input of TAVs can be recovered with high accuracy even with the lowest investigated spatial resolution. When optimizing the DCE-MRI protocol for hemodynamic analysis, increasing the spatial resolution of the images used for vessel segmentation is essential, and the spatial and temporal resolutions of the images used for the kinetic parameter fitting require simultaneous optimization. Conclusion An in silico validation framework was generated to systematically quantify the effects of image acquisition settings on the ability to accurately estimate tumor-associated characteristics.
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Affiliation(s)
- Chengyue Wu
- University of Texas at Austin, Oden Institute for Computational Engineering and Sciences, Austin, Texas, United States
- MD Anderson Cancer Center, Department of Imaging Physics, Houston, Texas, United States
- MD Anderson Cancer Center, Department of Breast Imaging, Houston, Texas, United States
- MD Anderson Cancer Center, Department of Biostatistics, Houston, Texas, United States
| | - David A. Hormuth
- University of Texas at Austin, Oden Institute for Computational Engineering and Sciences, Austin, Texas, United States
- University of Texas at Austin, Livestrong Cancer Institutes, Austin, Texas, United States
| | - Ty Easley
- Washington University in St. Louis, Department of Biomedical Engineering, St. Louis, Missouri, United States
| | - Federico Pineda
- University of Chicago, Department of Radiology, Chicago, Illinois, United States
| | - Gregory S. Karczmar
- University of Chicago, Department of Radiology, Chicago, Illinois, United States
| | - Thomas E. Yankeelov
- University of Texas at Austin, Oden Institute for Computational Engineering and Sciences, Austin, Texas, United States
- MD Anderson Cancer Center, Department of Imaging Physics, Houston, Texas, United States
- University of Texas at Austin, Livestrong Cancer Institutes, Austin, Texas, United States
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
- University of Texas at Austin, Department of Diagnostic Medicine, Austin, Texas, United States
- University of Texas at Austin, Department of Oncology, Austin, Texas, United States
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Søgaard SB, Andersen SB, Taghavi I, Hoyos CAV, Christoffersen C, Hansen KL, Jensen JA, Nielsen MB, Sørensen CM. Super-Resolution Ultrasound Imaging Provides Quantification of the Renal Cortical and Medullary Vasculature in Obese Zucker Rats: A Pilot Study. Diagnostics (Basel) 2022; 12:diagnostics12071626. [PMID: 35885531 PMCID: PMC9318608 DOI: 10.3390/diagnostics12071626] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/17/2022] [Accepted: 07/01/2022] [Indexed: 11/16/2022] Open
Abstract
Obesity is a risk factor of chronic kidney disease (CKD), leading to alterations in the renal vascular structure. This study tested if renal vascular density and tortuosity was quantifiable in vivo in obese rats using microbubble-based super-resolution ultrasound imaging. The kidneys of two 11-week-old and two 20-week-old male obese Zucker rats were compared with age-matched male lean Zucker rats. The super-resolution ultrasound images were manually divided into inner medulla, outer medulla, and cortex, and each area was subdivided into arteries and veins. We quantified vascular density and tortuosity, number of detected microbubbles, and generated tracks. For comparison, we assessed glomerular filtration rate, albumin/creatinine ratio, and renal histology to evaluate CKD. The number of detected microbubbles and generated tracks varied between animals and significantly affected quantification of vessel density. In areas with a comparable number of tracks, density increased in the obese animals, concomitant with a decrease in glomerular filtration rate and an increase in albumin/creatinine ratio, but without any pathology in the histological staining. The results indicate that super-resolution ultrasound imaging can be used to quantify structural alterations in the renal vasculature. Techniques to generate more comparable number of microbubble tracks and confirmation of the findings in larger-scale studies are needed.
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Affiliation(s)
- Stinne Byrholdt Søgaard
- Department of Diagnostic Radiology, Rigshospitalet, 2100 Copenhagen, Denmark; (S.B.A.); (K.L.H.); (M.B.N.)
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (C.C.); (C.M.S.)
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
- Correspondence:
| | - Sofie Bech Andersen
- Department of Diagnostic Radiology, Rigshospitalet, 2100 Copenhagen, Denmark; (S.B.A.); (K.L.H.); (M.B.N.)
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (C.C.); (C.M.S.)
| | - Iman Taghavi
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, 2800 Lyngby, Denmark; (I.T.); (J.A.J.)
| | | | - Christina Christoffersen
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (C.C.); (C.M.S.)
- Department of Clinical Biochemistry, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Kristoffer Lindskov Hansen
- Department of Diagnostic Radiology, Rigshospitalet, 2100 Copenhagen, Denmark; (S.B.A.); (K.L.H.); (M.B.N.)
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, 2800 Lyngby, Denmark; (I.T.); (J.A.J.)
| | - Michael Bachmann Nielsen
- Department of Diagnostic Radiology, Rigshospitalet, 2100 Copenhagen, Denmark; (S.B.A.); (K.L.H.); (M.B.N.)
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Charlotte Mehlin Sørensen
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (C.C.); (C.M.S.)
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Fan F, Kreher B, Keil H, Maier A, Huang Y. Fiducial marker recovery and detection from severely truncated data in navigation assisted spine surgery. Med Phys 2022; 49:2914-2930. [PMID: 35305271 DOI: 10.1002/mp.15617] [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: 09/07/2021] [Revised: 02/16/2022] [Accepted: 03/06/2022] [Indexed: 11/11/2022] Open
Abstract
PURPOSE Fiducial markers are commonly used in navigation assisted minimally invasive spine surgery and they help transfer image coordinates into real world coordinates. In practice, these markers might be located outside the field-of-view (FOV) of C-arm cone-beam computed tomography (CBCT) systems used in intraoperative surgeries, due to the limited detector sizes. As a consequence, reconstructed markers in CBCT volumes suffer from artifacts and have distorted shapes, which sets an obstacle for navigation. METHODS In this work, we propose two fiducial marker detection methods: direct detection from distorted markers (direct method) and detection after marker recovery (recovery method). For direct detection from distorted markers in reconstructed volumes, an efficient automatic marker detection method using two neural networks and a conventional circle detection algorithm is proposed. For marker recovery, a task-specific data preparation strategy is proposed to recover markers from severely truncated data. Afterwards, a conventional marker detection algorithm is applied for position detection. The networks in both methods are trained based on simulated data. For the direct method, 6800 images and 10000 images are generated respectively to train the U-Net and ResNet50. For the recovery method, the training set includes 1360 images for FBPConvNet and Pix2pixGAN. The simulated data set with 166 markers and 4 cadaver cases with real fiducials are used for evaluation. RESULTS The two methods are evaluated on simulated data and real cadaver data. The direct method achieves 100% detection rates within 1 mm detection error on simulated data with normal truncation and simulated data with heavier noise, but only detect 94.6% markers in extremely severe truncation case. The recovery method detects all the markers successfully in three test data sets and around 95% markers are detected within 0.5 mm error. For real cadaver data, both methods achieve 100% marker detection rates with mean registration error below 0.2 mm. CONCLUSIONS Our experiments demonstrate that the direct method is capable of detecting distorted markers accurately and the recovery method with the task-specific data preparation strategy has high robustness and generalizability on various data sets. The task-specific data preparation is able to reconstruct structures of interest outside the FOV from severely truncated data better than conventional data preparation. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Fuxin Fan
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91058, Germany
| | | | - Holger Keil
- Department of Trauma and Orthopedic Surgery, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
| | - Andreas Maier
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91058, Germany
| | - Yixing Huang
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
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Gladytz T, Millward JM, Cantow K, Hummel L, Zhao K, Flemming B, Periquito JS, Pohlmann A, Waiczies S, Seeliger E, Niendorf T. Reliable kidney size determination by magnetic resonance imaging in pathophysiological settings. Acta Physiol (Oxf) 2021; 233:e13701. [PMID: 34089569 DOI: 10.1111/apha.13701] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 05/05/2021] [Accepted: 06/01/2021] [Indexed: 12/24/2022]
Abstract
AIM Kidney diseases constitute a major health challenge, which requires noninvasive imaging to complement conventional approaches to diagnosis and monitoring. Several renal pathologies are associated with changes in kidney size, offering an opportunity for magnetic resonance imaging (MRI) biomarkers of disease. This work uses dynamic MRI and an automated bean-shaped model (ABSM) for longitudinal quantification of pathophysiologically relevant changes in kidney size. METHODS A geometry-based ABSM was developed for kidney size measurements in rats using parametric MRI (T2 , T2 * mapping). The ABSM approach was applied to longitudinal renal size quantification using occlusion of the (a) suprarenal aorta or (b) the renal vein, (c) increase in renal pelvis and intratubular pressure and (d) injection of an X-ray contrast medium into the thoracic aorta to induce pathophysiologically relevant changes in kidney size. RESULTS The ABSM yielded renal size measurements with accuracy and precision equivalent to the manual segmentation, with >70-fold time savings. The automated method could detect a ~7% reduction (aortic occlusion) and a ~5%, a ~2% and a ~6% increase in kidney size (venous occlusion, pelvis and intratubular pressure increase and injection of X-ray contrast medium, respectively). These measurements were not affected by reduced image quality following administration of ferumoxytol. CONCLUSION Dynamic MRI in conjunction with renal segmentation using an ABSM supports longitudinal quantification of changes in kidney size in pathophysiologically relevant experimental setups mimicking realistic clinical scenarios. This can potentially be instrumental for developing MRI-based diagnostic tools for various kidney disorders and for gaining new insight into mechanisms of renal pathophysiology.
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Affiliation(s)
- Thomas Gladytz
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Jason M Millward
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Kathleen Cantow
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Luis Hummel
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Kaixuan Zhao
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Bert Flemming
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Joāo S Periquito
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Institute of Physiology, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sonia Waiczies
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Erdmann Seeliger
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
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Wu C, Hormuth DA, Easley T, Eijkhout V, Pineda F, Karczmar GS, Yankeelov TE. An in silico validation framework for quantitative DCE-MRI techniques based on a dynamic digital phantom. Med Image Anal 2021; 73:102186. [PMID: 34329903 PMCID: PMC8453106 DOI: 10.1016/j.media.2021.102186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 07/08/2021] [Accepted: 07/16/2021] [Indexed: 10/20/2022]
Abstract
Quantitative evaluation of an image processing method to perform as designed is central to both its utility and its ability to guide the data acquisition process. Unfortunately, these tasks can be quite challenging due to the difficulty of experimentally obtaining the "ground truth" data to which the output of a given processing method must be compared. One way to address this issue is via "digital phantoms", which are numerical models that provide known biophysical properties of a particular object of interest. In this contribution, we propose an in silico validation framework for dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) acquisition and analysis methods that employs a novel dynamic digital phantom. The phantom provides a spatiotemporally-resolved representation of blood-interstitial flow and contrast agent delivery, where the former is solved by a 1D-3D coupled computational fluid dynamic system, and the latter described by an advection-diffusion equation. Furthermore, we establish a virtual simulator which takes as input the digital phantom, and produces realistic DCE-MRI data with controllable acquisition parameters. We assess the performance of a simulated standard-of-care acquisition (Protocol A) by its ability to generate contrast-enhanced MR images that separate vasculature from surrounding tissue, as measured by the contrast-to-noise ratio (CNR). We find that the CNR significantly decreases as the spatial resolution (SRA, where the subscript indicates Protocol A) or signal-to-noise ratio (SNRA) decreases. Specifically, with an SNRA / SRA = 75 dB / 30 μm, the median CNR is 77.30, whereas an SNRA / SRA = 5 dB / 300 μm reduces the CNR to 6.40. Additionally, we assess the performance of simulated ultra-fast acquisition (Protocol B) by its ability to generate DCE-MR images that capture contrast agent pharmacokinetics, as measured by error in the signal-enhancement ratio (SER) compared to ground truth (PESER). We find that PESER significantly decreases the as temporal resolution (TRB) increases. Similar results are reported for the effects of spatial resolution and signal-to-noise ratio on PESER. For example, with an SNRB / SRB / TRB = 5 dB / 300 μm / 10 s, the median PESER is 21.00%, whereas an SNRB / SRB / TRB = 75 dB / 60 μm / 1 s, yields a median PESER of 0.90%. These results indicate that our in silico framework can generate virtual MR images that capture effects of acquisition parameters on the ability of generated images to capture morphological or pharmacokinetic features. This validation framework is not only useful for investigations of perfusion-based MRI techniques, but also for the systematic evaluation and optimization new MRI acquisition, reconstruction, and image processing techniques.
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Affiliation(s)
- Chengyue Wu
- Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 E 24th St, Austin, TX 78712, United States.
| | - David A Hormuth
- Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 E 24th St, Austin, TX 78712, United States; Livestrong Cancer Institutes, United States
| | - Ty Easley
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, United States
| | | | - Federico Pineda
- Department of Radiology, The University of Chicago, Chicago, IL 60637, United States
| | - Gregory S Karczmar
- Department of Radiology, The University of Chicago, Chicago, IL 60637, United States
| | - Thomas E Yankeelov
- Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, 201 E 24th St, Austin, TX 78712, United States; Livestrong Cancer Institutes, United States; Departments of Biomedical Engineering, United States; Departments of Diagnostic Medicine, United States; Departments of Oncology, The University of Texas at Austin, Austin, TX 78712, United States; Department of Imaging Physics, MD Anderson Cancer Center, Houston, TX 77030, United States
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de Bournonville S, Geris L, Kerckhofs G. Micro computed tomography with and without contrast enhancement for the characterization of microcarriers in dry and wet state. Sci Rep 2021; 11:2819. [PMID: 33531524 PMCID: PMC7854591 DOI: 10.1038/s41598-021-81998-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 12/21/2020] [Indexed: 01/30/2023] Open
Abstract
In the field of regenerative medicine, microcarriers are used as support matrix for the growth of adherent cells. They are increasingly recognised as promising biomaterials for large scale, cost-effective cell expansion bioreactor processes. However, their individual morphologies can be highly heterogeneous which increases bioprocesses' variability. Additionally, only limited information is available on the microcarriers' 3D morphology and how it affects cell proliferation. Most imaging modalities do not provide sufficient 3D information or have a too limited field of view to appropriately study the 3D morphology. While microfocus X-ray computed tomography (microCT) could be appropriate, many microcarriers are hydrated before in-vitro use. This wet state makes them swell, changing considerably their morphology and making them indistinguishable from the culture solution in regular microCT images due to their physical density close to water. The use of contrast-enhanced microCT (CE-CT) has been recently reported for 3D imaging of soft materials. In this study, we selected a range of commercially available microcarrier types and used a combination of microCT and CE-CT for full 3D morphological characterization of large numbers of microcarriers, both in their dry and wet state. With in-house developed image processing and analysis tools, morphometrics of individual microcarriers were collected. Also, the morphology in wet state was assessed and related to accessible attachment surface area as a function of cell size. The morphological information on all microcarriers was collected in a publicly available database. This work provides a quantitative basis for optimization and modelling of microcarrier based cell expansion processes.
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Affiliation(s)
- Sébastien de Bournonville
- Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
- Biomechanics Section, Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
- Biomechanics Research Unit, ULiège, Liège, Belgium
| | - Liesbet Geris
- Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
- Biomechanics Section, Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
- Biomechanics Research Unit, ULiège, Liège, Belgium
| | - Greet Kerckhofs
- Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium.
- Biomechanics Lab, Institute of Mechanics, Materials and Civil Engineering, UCLouvain, Louvain-la-Neuve, Belgium.
- Department Materials Engineering, KU Leuven, Leuven, Belgium.
- Institute of Experimental and Clinical Research, UCLouvain, Woluwé-Saint-Lambert, Belgium.
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8
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Gao Y, Yuan D, Gai L, Wu X, Shi Y, He Y, Liu C, Zhang C, Zhou G, Yuan C. Saponins from Panax japonicus ameliorate age-related renal fibrosis by inhibition of inflammation mediated by NF-κB and TGF-β1/Smad signaling and suppression of oxidative stress via activation of Nrf2-ARE signaling. J Ginseng Res 2020; 45:408-419. [PMID: 34025134 PMCID: PMC8134850 DOI: 10.1016/j.jgr.2020.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/22/2020] [Accepted: 08/26/2020] [Indexed: 12/23/2022] Open
Abstract
Background The decreased renal function is known to be associated with biological aging, of which the main pathological features are chronic inflammation and renal interstitial fibrosis. In previous studies, we reported that total saponins from Panax japonicus (SPJs) can availably protect acute myocardial ischemia. We proposed that SPJs might have similar protective effects for aging-associated renal interstitial fibrosis. Thus, in the present study, we evaluated the overall effect of SPJs on renal fibrosis. Methods Sprague-Dawley (SD) aging rats were given SPJs by gavage beginning from 18 months old, at 10 mg/kg/d and 60 mg/kg/d, up to 24 months old. After the experiment, changes in morphology, function and fibrosis of their kidneys were detected. The levels of serum uric acid (UA), β2-microglobulin (β2-MG) and cystatin C (Cys C) were assayed with ELISA kits. The levels of extracellular matrix (ECM), matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), inflammatory factors and changes of oxidative stress parameters were examined. Results After SPJs treatment, SD rats showed significantly histopathological changes in kidneys accompanied by decreased renal fibrosis and increased renal function; As compared with those in 3-month group, the levels of serum UA, Cys C and β2-MG in 24-month group were significantly increased (p < 0.05). Compared with those in the 24-month group, the levels of serum UA, Cys C and β2-MG in the SPJ-H group were significantly decreased. While ECM was reduced and the levels of MMP-2 and MMP-9 were increased, the levels of TIMP-1, TIMP-2 and transforming growth factor-β1 (TGF-β1)/Smad signaling were decreased; the expression level of phosphorylated nuclear factor kappa-B (NF-κB) was down-regulated with reduced inflammatory factors; meanwhile, the expression of nuclear factor erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) signaling was aggrandized. Conclusion These results suggest that SPJs treatment can improve age-associated renal fibrosis by inhibiting TGF-β1/Smad, NFκB signaling pathways and activating Nrf2-ARE signaling pathways and that SPJs can be a potentially valuable anti-renal fibrosis drug.
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Key Words
- ARE, antioxidant response element
- Aging
- COX2, cyclooxygenase-2
- Cys C, cystatin C
- ECM, extracellular matrix
- HO-1, human heme oxygenase 1
- IL-6, interleukin-6
- IκB, inhibitor of NF-κB
- LPO, lipid peroxides
- MCP-1, monocyte chemoattractant protein-1
- MMPs, matrix metalloproteinases
- NF-κB, nuclear factor kappa-B
- NQO1, recombinant NADH dehydrogenase quinone 1
- Nrf2, nuclear factor erythroid 2-related factor 2
- Nrf2-ARE signaling pathways
- PJ, Panax japonicas
- Renal fibrosis
- SD, Sprague-Dawley
- SPJ-H, high-dose of SPJ
- SPJ-L, low-dose of SPJ
- SPJs, saponins from panax japonicus
- TGF-β1, tumor growth factor-β1
- TGF-β1/Smad
- TIMPs, tissue inhibitors of metalloproteinases
- TNF-α, tumor necrosis factor-α
- Total saponins of panax japonicus
- UA, uric acid
- α-SMA, α-smooth muscle aorta
- β2-MG, β2-microglobulin
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Affiliation(s)
- Yan Gao
- College of Medical Science, China Three Gorges University, Yichang, China
| | - Ding Yuan
- College of Medical Science, China Three Gorges University, Yichang, China
| | - Liyue Gai
- College of Medical Science, China Three Gorges University, Yichang, China
| | - Xuelian Wu
- College of Medical Science, China Three Gorges University, Yichang, China
| | - Yue Shi
- College of Medical Science, China Three Gorges University, Yichang, China
| | - Yumin He
- College of Medical Science, China Three Gorges University, Yichang, China
| | - Chaoqi Liu
- College of Medical Science, China Three Gorges University, Yichang, China
| | - Changcheng Zhang
- College of Medical Science, China Three Gorges University, Yichang, China
| | - Gang Zhou
- College of Traditional Chinese Medicine, China Three Gorges University, Yichang, China
| | - Chengfu Yuan
- College of Medical Science, China Three Gorges University, Yichang, China.,Third-Grade Pharmacological Laboratory on Chinese Medicine Approved by State Administration of Traditional Chinese Medicine, China Three Gorges University, Yichang, China
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9
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Zeng X, Ma S, Kruger JM, Wang R, Tan X, Qian C. High-resolution MRI of kidney microstructures at 7.05 T with an endo-colonic Wireless Amplified NMR detector. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 303:121-127. [PMID: 31051387 PMCID: PMC6590910 DOI: 10.1016/j.jmr.2019.04.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/19/2019] [Accepted: 04/21/2019] [Indexed: 05/06/2023]
Abstract
To map the hemodynamic responses of kidney microstructures at 7.05 T with improved sensitivity, a Wireless Amplified NMR Detector (WAND) with cylindrical symmetry was fabricated as an endoluminal detector that can convert externally provided wireless signal at 600.71 MHz into amplified MR signals at 300.33 MHz. When this detector was inserted inside colonic lumens to sensitively observe adjacent kidneys, it could clearly identify kidney microstructures in the renal cortex and renal medullary. Owing to the higher achievable spatial resolution, differential hemodynamic responses of kidney microstructures under different breathing conditions could be individually quantified to estimate the underlying correlation between oxygen bearing capability and local levels of oxygen unsaturation. The WAND's ability to map Blood Oxygen Level Dependent (BOLD) signal responses in heterogeneous microstructures will pave way for early-stage diagnosis of kidney diseases, without the use of contrast agents for reduced tissue retention and toxicity.
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Affiliation(s)
- Xianchun Zeng
- Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China; Department of Radiology, Michigan State University, East Lansing, MI, USA
| | - Shuangtao Ma
- Department of Medicine, Michigan State University, East Lansing, MI, USA
| | - John M Kruger
- Veterinary Medical Center, Michigan State University, East Lansing, MI, USA
| | - Rongpin Wang
- Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Xiaobo Tan
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA
| | - Chunqi Qian
- Department of Radiology, Michigan State University, East Lansing, MI, USA.
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10
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Xie L, Koukos G, Barck K, Foreman O, Lee WP, Brendza R, Eastham-Anderson J, McKenzie BS, Peterson A, Carano RAD. Micro-CT imaging and structural analysis of glomeruli in a model of Adriamycin-induced nephropathy. Am J Physiol Renal Physiol 2018; 316:F76-F89. [PMID: 30256127 DOI: 10.1152/ajprenal.00331.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glomeruli number and size are important for determining the pathogenesis of glomerular disease, chronic kidney disease, and hypertension. Moreover, renal injury can occur in specific cortical layers and alter glomerular spatial distribution. In this study, we present a comprehensive structural analysis of glomeruli in a model of Adriamycin (doxorubicin) nephropathy. Glomeruli are imaged (micro-CT at 10 × 10 × 10 μm3) in kidney specimens from C57Bl/6 mouse cohorts: control treated with saline ( n = 9) and Adriamycin treated with 20 mg/kg Adriamycin ( n = 7). Several indices were examined, including glomerular number, glomerular volume, glomerular volume heterogeneity, and spatial density at each glomerulus and in each cortical layer (superficial, midcortical, and juxtamedullary). In the Adriamycin-treated animals, glomerular number decreased significantly in the left kidney [control: 8,298 ± 221, Adriamycin: 6,781 ± 630 (mean ± SE)] and right kidney (control: 7,317 ± 367, Adriamycin: 5,522 ± 508), and glomerular volume heterogeneity increased significantly in the left kidney (control: 0.642 ± 0.015, Adriamycin: 0.786 ± 0.018) and right kidney (control: 0.739 ± 0.016, Adriamycin: 0.937 ± 0.023). Glomerular spatial density was not affected. Glomerular volume heterogeneity increased significantly in the superficial and midcortical layers of the Adriamycin cohort. Adriamycin did not affect glomerular volume or density metrics in the juxtamedullary region, suggesting a compensatory mechanism of juxtamedullary glomeruli to injury in the outer cortical layers. Left/right asymmetry was observed in kidney size and various glomeruli metrics. The methods presented here can be used to evaluate renal disease models with subtle changes in glomerular endowment locally or across the entire kidney, and they provide an imaging tool to investigate diverse interventions and therapeutic drugs.
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Affiliation(s)
- Luke Xie
- Biomedical Imaging, Genentech, South San Francisco, California
| | - Georgios Koukos
- Molecular Biology, Genentech, South San Francisco, California
| | - Kai Barck
- Biomedical Imaging, Genentech, South San Francisco, California
| | - Oded Foreman
- Pathology, Genentech, South San Francisco, California
| | - Wyne P Lee
- Translation Immunology, Genentech, South San Francisco, California
| | - Robert Brendza
- Neuroscience, Genentech, South San Francisco, California
| | | | - Brent S McKenzie
- Translation Immunology, Genentech, South San Francisco, California
| | - Andrew Peterson
- Molecular Biology, Genentech, South San Francisco, California
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11
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Amelioratory Effects of Testosterone Propionate on Age-related Renal Fibrosis via Suppression of TGF-β1/Smad Signaling and Activation of Nrf2-ARE Signaling. Sci Rep 2018; 8:10726. [PMID: 30013094 PMCID: PMC6048025 DOI: 10.1038/s41598-018-29023-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 07/04/2018] [Indexed: 12/18/2022] Open
Abstract
Androgen plays a pivotal role in the progression of renal fibrosis. However, whether exogenous androgen treatment to aged male rats can improve the age-related renal fibrosis was not explored. In our study, the changes of morphological structure, renal fibrosis, ultrastructure and renal function, the expressions of extracellular matrix (ECM), matrix metalloproteinases (MMPs) and its tissue inhibitors of metalloproteinases (TIMPs), the expressions of tumor growth factor β1 (TGF-β1)/Smad signaling and oxidative stress parameters as well as nuclear factor erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) signaling were tested in kidney of aged male Wistar rats after subcutaneous testosterone propionate (TP, 2 mg/kg/d, 84-day) injection. Aged rats showed significantly renal histopathological changes, increased renal fibrosis, increased thickening of the glomerular basement membrane and the Bowman’s capsule basement membrane, declined renal functional, increased ECM, lower expressions of MMP-2 and MMP-9 and higher expressions of TIMP-1 and TIMP-2 in renal tissues and higher expressions of TGF-β1/Smad signaling, as well as lower expressions of Nrf2-ARE signaling compared to young rats. TP treatment significantly improved age-related above indexes. These results suggested that TP supplement may alleviate age-related renal fibrosis via suppression of TGF-β1/Smad signaling and activation of Nrf2-ARE signaling in aged rats.
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12
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Khan Z, Ngo JP, Le B, Evans RG, Pearson JT, Gardiner BS, Smith DW. Three-dimensional morphometric analysis of the renal vasculature. Am J Physiol Renal Physiol 2018; 314:F715-F725. [DOI: 10.1152/ajprenal.00339.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Vascular topology and morphology are critical in the regulation of blood flow and the transport of small solutes, including oxygen, carbon dioxide, nitric oxide, and hydrogen sulfide. Renal vascular morphology is particularly challenging, since many arterial walls are partially wrapped by the walls of veins. In the absence of a precise characterization of three-dimensional branching vascular geometry, accurate computational modeling of the intrarenal transport of small diffusible molecules is impossible. An enormous manual effort was required to achieve a relatively precise characterization of rat renal vascular geometry, highlighting the need for an automated method for analysis of branched vasculature morphology to allow characterization of the renal vascular geometry of other species, including humans. We present a semisupervised method for three-dimensional morphometric analysis of renal vasculature images generated by computed tomography. We derive quantitative vascular attributes important to mass transport between arteries, veins, and the renal tissue and present methods for their computation for a three-dimensional vascular geometry. To validate the algorithm, we compare automated vascular estimates with subjective manual measurements for a portion of rabbit kidney. Although increased image resolution can improve outcomes, our results demonstrate that the method can quantify the morphological characteristics of artery-vein pairs, comparing favorably with manual measurements. Similar to the rat, we show that rabbit artery-vein pairs become less intimate along the course of the renal vasculature, but the total wrapped mass transfer coefficient increases and then decreases. This new method will facilitate new quantitative physiological models describing the transport of small molecules within the kidney.
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Affiliation(s)
- Zohaib Khan
- School of Information Technology and Mathematical Sciences, University of South Australia, Adelaide, Australia
| | - Jennifer P. Ngo
- Cardiovascular Disease Program, Biosciences Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia
| | - Bianca Le
- Cardiovascular Disease Program, Biosciences Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia
| | - Roger G. Evans
- Cardiovascular Disease Program, Biosciences Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia
| | - James T. Pearson
- Cardiovascular Disease Program, Biosciences Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Bruce S. Gardiner
- School of Engineering and Information Technology, Murdoch University, Perth, Australia
| | - David W. Smith
- Faculty of Engineering and Mathematical Sciences, The University of Western Australia, Perth, Australia
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13
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Lovreglio P, Das S, Buist KA, Peters EAJF, Pel L, Kuipers JAM. Experimental and numerical investigation of structure and hydrodynamics in packed beds of spherical particles. AIChE J 2018. [DOI: 10.1002/aic.16127] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- P. Lovreglio
- Multiphase Reactors Group, Dept. of Chemical Engineering & ChemistryEindhoven University of TechnologyEindhoven5600 MB The Netherlands
| | - S. Das
- Multiphase Reactors Group, Dept. of Chemical Engineering & ChemistryEindhoven University of TechnologyEindhoven5600 MB The Netherlands
| | - K. A. Buist
- Multiphase Reactors Group, Dept. of Chemical Engineering & ChemistryEindhoven University of TechnologyEindhoven5600 MB The Netherlands
| | - E. A. J. F. Peters
- Multiphase Reactors Group, Dept. of Chemical Engineering & ChemistryEindhoven University of TechnologyEindhoven5600 MB The Netherlands
| | - L. Pel
- Transport in Permeable Media Group, Dept. of Applied PhysicsEindhoven University of TechnologyEindhoven5600 MB The Netherlands
| | - J. A. M. Kuipers
- Multiphase Reactors Group, Dept. of Chemical Engineering & ChemistryEindhoven University of TechnologyEindhoven5600 MB The Netherlands
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14
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Wang Y, Lu T, Li X, Ren S, Bi S. Robust nanobubble and nanodroplet segmentation in atomic force microscope images using the spherical Hough transform. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:2572-2582. [PMID: 29259872 PMCID: PMC5727802 DOI: 10.3762/bjnano.8.257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 11/16/2017] [Indexed: 05/25/2023]
Abstract
Interfacial nanobubbles (NBs) and nanodroplets (NDs) have been attracting increasing attention due to their potential for numerous applications. As a result, the automated segmentation and morphological characterization of NBs and NDs in atomic force microscope (AFM) images is highly awaited. The current segmentation methods suffer from the uneven background in AFM images due to thermal drift and hysteresis of AFM scanners. In this study, a two-step approach was proposed to segment NBs and NDs in AFM images in an automated manner. The spherical Hough transform (SHT) and a boundary optimization operation were combined to achieve robust segmentation. The SHT was first used to preliminarily detect NBs and NDs. After that, the so-called contour expansion operation was applied to achieve optimized boundaries. The principle and the detailed procedure of the proposed method were presented, followed by the demonstration of the automated segmentation and morphological characterization. The result shows that the proposed method gives an improved segmentation result compared with the thresholding and circle Hough transform method. Moreover, the proposed method shows strong robustness of segmentation in AFM images with an uneven background.
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Affiliation(s)
- Yuliang Wang
- School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, P. R. China
| | - Tongda Lu
- School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, P. R. China
| | - Xiaolai Li
- School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, P. R. China
| | - Shuai Ren
- School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, P. R. China
| | - Shusheng Bi
- School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, P. R. China
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15
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Than VD, Tang AM, Roux JN, Pereira JM, Aimedieu P, Bornert M. Investigation into macroscopic and microscopic behaviors of wet granular soils using discrete element method and X-ray computed tomography. EPJ WEB OF CONFERENCES 2017. [DOI: 10.1051/epjconf/201714008018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Weavers PT, Tao S, Trzasko JD, Shu Y, Tryggestad EJ, Gunter JL, McGee KP, Litwiller DV, Hwang KP, Bernstein MA. Image-based gradient non-linearity characterization to determine higher-order spherical harmonic coefficients for improved spatial position accuracy in magnetic resonance imaging. Magn Reson Imaging 2016; 38:54-62. [PMID: 28034637 DOI: 10.1016/j.mri.2016.12.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 12/22/2016] [Accepted: 12/22/2016] [Indexed: 11/30/2022]
Abstract
PURPOSE Spatial position accuracy in magnetic resonance imaging (MRI) is an important concern for a variety of applications, including radiation therapy planning, surgical planning, and longitudinal studies of morphologic changes to study neurodegenerative diseases. Spatial accuracy is strongly influenced by gradient linearity. This work presents a method for characterizing the gradient non-linearity fields on a per-system basis, and using this information to provide improved and higher-order (9th vs. 5th) spherical harmonic coefficients for better spatial accuracy in MRI. METHODS A large fiducial phantom containing 5229 water-filled spheres in a grid pattern is scanned with the MR system, and the positions all the fiducials are measured and compared to the corresponding ground truth fiducial positions as reported from a computed tomography (CT) scan of the object. Systematic errors from off-resonance (i.e., B0) effects are minimized with the use of increased receiver bandwidth (±125kHz) and two acquisitions with reversed readout gradient polarity. The spherical harmonic coefficients are estimated using an iterative process, and can be subsequently used to correct for gradient non-linearity. Test-retest stability was assessed with five repeated measurements on a single scanner, and cross-scanner variation on four different, identically-configured 3T wide-bore systems. RESULTS A decrease in the root-mean-square error (RMSE) over a 50cm diameter spherical volume from 1.80mm to 0.77mm is reported here in the case of replacing the vendor's standard 5th order spherical harmonic coefficients with custom fitted 9th order coefficients, and from 1.5mm to 1mm by extending custom fitted 5th order correction to the 9th order. Minimum RMSE varied between scanners, but was stable with repeated measurements in the same scanner. CONCLUSIONS The results suggest that the proposed methods may be used on a per-system basis to more accurately calibrate MR gradient non-linearity coefficients when compared to vendor standard corrections.
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Affiliation(s)
- Paul T Weavers
- Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States
| | - Shengzhen Tao
- Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States; Mayo Graduate School, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States
| | - Joshua D Trzasko
- Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States
| | - Yunhong Shu
- Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States
| | - Erik J Tryggestad
- Radiation Oncology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States
| | - Jeffrey L Gunter
- Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States
| | - Kiaran P McGee
- Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States
| | | | - Ken-Pin Hwang
- MD Anderson Cancer Center, 1515 Holcomb Blvd, Houston, TX 77030, United States
| | - Matt A Bernstein
- Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States.
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17
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Xie L, Bennett KM, Liu C, Johnson GA, Zhang JL, Lee VS. MRI tools for assessment of microstructure and nephron function of the kidney. Am J Physiol Renal Physiol 2016; 311:F1109-F1124. [PMID: 27630064 DOI: 10.1152/ajprenal.00134.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 09/08/2016] [Indexed: 12/13/2022] Open
Abstract
MRI can provide excellent detail of renal structure and function. Recently, novel MR contrast mechanisms and imaging tools have been developed to evaluate microscopic kidney structures including the tubules and glomeruli. Quantitative MRI can assess local tubular function and is able to determine the concentrating mechanism of the kidney noninvasively in real time. Measuring single nephron function is now a near possibility. In parallel to advancing imaging techniques for kidney microstructure is a need to carefully understand the relationship between the local source of MRI contrast and the underlying physiological change. The development of these imaging markers can impact the accurate diagnosis and treatment of kidney disease. This study reviews the novel tools to examine kidney microstructure and local function and demonstrates the application of these methods in renal pathophysiology.
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Affiliation(s)
- Luke Xie
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, Utah;
| | - Kevin M Bennett
- Department of Biology, University of Hawaii at Manoa, Honolulu, Hawaii
| | - Chunlei Liu
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina; and.,Brain Imaging and Analysis Center, Duke University Medical Center, Durham, North Carolina
| | - G Allan Johnson
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina; and
| | - Jeff Lei Zhang
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, Utah
| | - Vivian S Lee
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, Utah
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18
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Wei H, Xie L, Dibb R, Li W, Decker K, Zhang Y, Johnson GA, Liu C. Imaging whole-brain cytoarchitecture of mouse with MRI-based quantitative susceptibility mapping. Neuroimage 2016; 137:107-115. [PMID: 27181764 PMCID: PMC5201162 DOI: 10.1016/j.neuroimage.2016.05.033] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/15/2016] [Accepted: 05/10/2016] [Indexed: 01/05/2023] Open
Abstract
The proper microstructural arrangement of complex neural structures is essential for establishing the functional circuitry of the brain. We present an MRI method to resolve tissue microstructure and infer brain cytoarchitecture by mapping the magnetic susceptibility in the brain at high resolution. This is possible because of the heterogeneous magnetic susceptibility created by varying concentrations of lipids, proteins and irons from the cell membrane to cytoplasm. We demonstrate magnetic susceptibility maps at a nominal resolution of 10-μm isotropic, approaching the average cell size of a mouse brain. The maps reveal many detailed structures including the retina cell layers, olfactory sensory neurons, barrel cortex, cortical layers, axonal fibers in white and gray matter. Olfactory glomerulus density is calculated and structural connectivity is traced in the optic nerve, striatal neurons, and brainstem nerves. The method is robust and can be readily applied on MRI scanners at or above 7T.
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Affiliation(s)
- Hongjiang Wei
- Brain Imaging and Analysis Center, Duke University, Durham, NC 27705, USA
| | - Luke Xie
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, UT 84108, USA
| | - Russell Dibb
- Center for In Vivo Microscopy, Duke University, Durham, NC 27705, USA
| | - Wei Li
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Kyle Decker
- Center for In Vivo Microscopy, Duke University, Durham, NC 27705, USA
| | - Yuyao Zhang
- Brain Imaging and Analysis Center, Duke University, Durham, NC 27705, USA
| | - G Allan Johnson
- Center for In Vivo Microscopy, Duke University, Durham, NC 27705, USA; Department of Radiology, School of Medicine, Duke University, Durham, NC 27705, USA
| | - Chunlei Liu
- Brain Imaging and Analysis Center, Duke University, Durham, NC 27705, USA; Department of Radiology, School of Medicine, Duke University, Durham, NC 27705, USA.
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19
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Niendorf T, Pohlmann A, Reimann HM, Waiczies H, Peper E, Huelnhagen T, Seeliger E, Schreiber A, Kettritz R, Strobel K, Ku MC, Waiczies S. Advancing Cardiovascular, Neurovascular, and Renal Magnetic Resonance Imaging in Small Rodents Using Cryogenic Radiofrequency Coil Technology. Front Pharmacol 2015; 6:255. [PMID: 26617515 PMCID: PMC4642111 DOI: 10.3389/fphar.2015.00255] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 10/19/2015] [Indexed: 12/11/2022] Open
Abstract
Research in pathologies of the brain, heart and kidney have gained immensely from the plethora of studies that have helped shape new methods in magnetic resonance (MR) for characterizing preclinical disease models. Methodical probing into preclinical animal models by MR is invaluable since it allows a careful interpretation and extrapolation of data derived from these models to human disease. In this review we will focus on the applications of cryogenic radiofrequency (RF) coils in small animal MR as a means of boosting image quality (e.g., by supporting MR microscopy) and making data acquisition more efficient (e.g., by reducing measuring time); both being important constituents for thorough investigational studies on animal models of disease. This review attempts to make the (bio)medical imaging, molecular medicine, and pharmaceutical communities aware of this productive ferment and its outstanding significance for anatomical and functional MR in small rodents. The goal is to inspire a more intense interdisciplinary collaboration across the fields to further advance and progress non-invasive MR methods that ultimately support thorough (patho)physiological characterization of animal disease models. In this review, current and potential future applications for the RF coil technology in cardiovascular, neurovascular, and renal disease will be discussed.
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Affiliation(s)
- Thoralf Niendorf
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlin, Germany
- German Centre for Cardiovascular ResearchBerlin, Germany
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlin, Germany
| | - Henning M. Reimann
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlin, Germany
| | | | - Eva Peper
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlin, Germany
| | - Till Huelnhagen
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlin, Germany
| | - Erdmann Seeliger
- Center for Cardiovascular Research, Institute of Physiology, Charité—Universitätsmedizin BerlinBerlin, Germany
| | - Adrian Schreiber
- Clinic for Nephrology and Intensive Care Medicine, Charité Medical Faculty and Experimental and Clinical Research CenterBerlin, Germany
| | - Ralph Kettritz
- Clinic for Nephrology and Intensive Care Medicine, Charité Medical Faculty and Experimental and Clinical Research CenterBerlin, Germany
| | | | - Min-Chi Ku
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlin, Germany
| | - Sonia Waiczies
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlin, Germany
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20
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Tempel-Brami C, Schiffenbauer YS, Nyska A, Ezov N, Spector I, Abramovitch R, Maronpot RR. Practical Applications of in Vivo and ex Vivo MRI in Toxicologic Pathology Using a Novel High-performance Compact MRI System. Toxicol Pathol 2015; 43:633-50. [PMID: 25694086 DOI: 10.1177/0192623314568390] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Magnetic resonance imaging (MRI) is widely used in preclinical research and drug development and is a powerful noninvasive method for assessment of phenotypes and therapeutic efficacy in murine models of disease. In vivo MRI provides an opportunity for longitudinal evaluation of tissue changes and phenotypic expression in experimental animal models. Ex vivo MRI of fixed samples permits a thorough examination of multiple digital slices while leaving the specimen intact for subsequent conventional hematoxylin and eosin (H&E) histology. With the advent of new compact MRI systems that are designed to operate in most conventional labs without the cost, complexity, and infrastructure needs of conventional MRI systems, the possibility of MRI becoming a practical modality is now viable. The purpose of this study was to investigate the capabilities of a new compact, high-performance MRI platform (M2™; Aspect Imaging, Israel) as it relates to preclinical toxicology studies. This overview will provide examples of major organ system pathologies with an emphasis on how compact MRI can serve as an important adjunct to conventional pathology by nondestructively providing 3-dimensional (3-D) digital data sets, detailed morphological insights, and quantitative information. Comparative data using compact MRI for both in vivo and ex vivo are provided as well as validation using conventional H&E.
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Affiliation(s)
| | | | - Abraham Nyska
- Tel Aviv University and Consultant in Toxicologic Pathology, Timrat, Tel Aviv, Israel
| | - Nati Ezov
- Harlan Biotech Israel, Nes Ziona, Israel
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21
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Niendorf T, Pohlmann A, Arakelyan K, Flemming B, Cantow K, Hentschel J, Grosenick D, Ladwig M, Reimann H, Klix S, Waiczies S, Seeliger E. How bold is blood oxygenation level-dependent (BOLD) magnetic resonance imaging of the kidney? Opportunities, challenges and future directions. Acta Physiol (Oxf) 2015; 213:19-38. [PMID: 25204811 DOI: 10.1111/apha.12393] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 07/04/2014] [Accepted: 09/04/2014] [Indexed: 12/11/2022]
Abstract
Renal tissue hypoperfusion and hypoxia are key elements in the pathophysiology of acute kidney injury and its progression to chronic kidney disease. Yet, in vivo assessment of renal haemodynamics and tissue oxygenation remains a challenge. Many of the established approaches are invasive, hence not applicable in humans. Blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) offers an alternative. BOLD-MRI is non-invasive and indicative of renal tissue oxygenation. Nonetheless, recent (pre-) clinical studies revived the question as to how bold renal BOLD-MRI really is. This review aimed to deliver some answers. It is designed to inspire the renal physiology, nephrology and imaging communities to foster explorations into the assessment of renal oxygenation and haemodynamics by exploiting the powers of MRI. For this purpose, the specifics of renal oxygenation and perfusion are outlined. The fundamentals of BOLD-MRI are summarized. The link between tissue oxygenation and the oxygenation-sensitive MR biomarker T2∗ is outlined. The merits and limitations of renal BOLD-MRI in animal and human studies are surveyed together with their clinical implications. Explorations into detailing the relation between renal T2∗ and renal tissue partial pressure of oxygen (pO2 ) are discussed with a focus on factors confounding the T2∗ vs. tissue pO2 relation. Multi-modality in vivo approaches suitable for detailing the role of the confounding factors that govern T2∗ are considered. A schematic approach describing the link between renal perfusion, oxygenation, tissue compartments and renal T2∗ is proposed. Future directions of MRI assessment of renal oxygenation and perfusion are explored.
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Affiliation(s)
- T. Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - A. Pohlmann
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - K. Arakelyan
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
| | - B. Flemming
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
| | - K. Cantow
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
| | - J. Hentschel
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - D. Grosenick
- Physikalisch-Technische Bundesanstalt (PTB); Berlin Germany
| | - M. Ladwig
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
| | - H. Reimann
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - S. Klix
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - S. Waiczies
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - E. Seeliger
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
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22
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Qian C, Yu X, Pothayee N, Dodd S, Bouraoud N, Star R, Bennett K, Koretsky A. Live nephron imaging by MRI. Am J Physiol Renal Physiol 2014; 307:F1162-8. [PMID: 25186296 DOI: 10.1152/ajprenal.00326.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The local sensitivity of MRI can be improved with small MR detectors placed close to regions of interest. However, to maintain such sensitivity advantage, local detectors normally need to communicate with the external amplifier through cable connections, which prevent the use of local detectors as implantable devices. Recently, an integrated wireless amplifier was developed that can efficiently amplify and broadcast locally detected signals, so that the local sensitivity was enhanced without the need for cable connections. This integrated detector enabled the live imaging of individual glomeruli using negative contrast introduced by cationized ferritin, and the live imaging of renal tubules using positive contrast introduced by gadopentetate dimeglumine. Here, we utilized the high blood flow to image individual glomeruli as hyperintense regions without any contrast agent. These hyperintense regions were identified for pixels with signal intensities higher than the local average. Addition of Mn(2+) allowed the simultaneous detection of both glomeruli and renal tubules: Mn(2+) was primarily reabsorbed by renal tubules, which would be distinguished from glomeruli due to higher enhancement in T1-weighted MRI. Dynamic studies of Mn(2+) absorption confirmed the differential absorption affinity of glomeruli and renal tubules, potentially enabling the in vivo observation of nephron function.
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Affiliation(s)
- Chunqi Qian
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, Maryland;
| | - Xin Yu
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, Maryland; High-Field Magnetic Resonance Department, Max Planck Institute for Biological Cybernetics, Tubingen, Germany
| | - Nikorn Pothayee
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Stephen Dodd
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Nadia Bouraoud
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Robert Star
- Division of Kidney Urologic and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Kevin Bennett
- Department of Biology, University of Hawaii, Honolulu, Hawaii; and
| | - Alan Koretsky
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, Maryland
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Xie L, Subashi E, Qi Y, Knepper MA, Johnson GA. Four-dimensional MRI of renal function in the developing mouse. NMR IN BIOMEDICINE 2014; 27:1094-102. [PMID: 25066408 PMCID: PMC4134394 DOI: 10.1002/nbm.3162] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/13/2014] [Accepted: 06/22/2014] [Indexed: 05/02/2023]
Abstract
The major roles of filtration, metabolism and high blood flow make the kidney highly vulnerable to drug-induced toxicity and other renal injuries. A method to follow kidney function is essential for the early screening of toxicity and malformations. In this study, we acquired high spatiotemporal resolution (four dimensional) datasets of normal mice to follow changes in kidney structure and function during development. The data were acquired with dynamic contrast-enhanced MRI (via keyhole imaging) and a cryogenic surface coil, allowing us to obtain a full three-dimensional image (isotropic resolution, 125 microns) every 7.7 s over a 50-min scan. This time course permitted the demonstration of both contrast enhancement and clearance. Functional changes were measured over a 17-week course (at 3, 5, 7, 9, 13 and 17 weeks). The time dimension of the MRI dataset was processed to produce unique image contrasts to segment the four regions of the kidney: cortex (CO), outer stripe (OS) of the outer medulla (OM), inner stripe (IS) of the OM and inner medulla (IM). Local volumes, time-to-peak (TTP) values and decay constants (DC) were measured in each renal region. These metrics increased significantly with age, with the exception of DC values in the IS and OS. These data will serve as a foundation for studies of normal renal physiology and future studies of renal diseases that require early detection and intervention.
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Affiliation(s)
- Luke Xie
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
| | - Ergys Subashi
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710
- Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina, 27710
| | - Yi Qi
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Mark A. Knepper
- Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, 20892-1603
| | - G. Allan Johnson
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
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24
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Xie L, Dibb R, Cofer GP, Li W, Nicholls PJ, Johnson GA, Liu C. Susceptibility tensor imaging of the kidney and its microstructural underpinnings. Magn Reson Med 2014; 73:1270-81. [PMID: 24700637 DOI: 10.1002/mrm.25219] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 02/14/2014] [Accepted: 02/19/2014] [Indexed: 12/14/2022]
Abstract
PURPOSE The purpose of this study was to determine whether susceptibility tensor imaging (STI) could overcome limitations of current techniques to detect tubules throughout the kidney. METHODS Normal mouse kidneys (n = 4) were imaged at 9.4T using a three-dimensional gradient multi-echo sequence (55-micron isotropic resolution). Phase images from 12 orientations were obtained to compute the susceptibility tensor. Diffusion tensor imaging (DTI) with 12 encoding directions was compared with STI. Tractography was performed to visualize and track the course of tubules with DTI and STI. Confocal microscopy was used to identify which tubular segments of the nephron were detected by DTI and STI. RESULTS Diffusion anisotropy was limited to the inner medulla of the kidney. DTI did not find a significant number of coherent tubular tracks in the outer medulla or cortex. With STI, we found strong susceptibility anisotropy and many tracks in the inner and outer medulla and in limited areas of the cortex. CONCLUSION STI was able to track tubules throughout the kidney, whereas DTI was limited to the inner medulla. STI provides a novel contrast mechanism related to local tubule microstructure and may offer a powerful method to study the nephron.
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Affiliation(s)
- Luke Xie
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA; Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
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25
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Bertram JF, Cullen-McEwen LA, Egan GF, Gretz N, Baldelomar E, Beeman SC, Bennett KM. Why and how we determine nephron number. Pediatr Nephrol 2014; 29:575-80. [PMID: 24022365 DOI: 10.1007/s00467-013-2600-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 07/25/2013] [Accepted: 08/02/2013] [Indexed: 01/23/2023]
Abstract
The total number of glomeruli (nephrons) in a kidney is an important microanatomical parameter for at least three reasons: it provides an index of the success/extent of nephrogenesis and can thereby provide insights into the roles of specific genes and feto-maternal environmental factors in nephrogenesis; low nephron number has been linked to an increased risk of cardiovascular and renal disease in adulthood; and knowledge of quantitative kidney microanatomy can illuminate our understanding of physiological mechanisms in health and disease. A range of methods has been used to count glomeruli in kidneys over the past 100 years, with design-based stereology (the physical disector/fractionator combination) considered the gold standard. However, this approach is labor-intensive and expensive, and therefore is not utilized by most laboratories. A new method for counting and sizing every glomerulus in the kidney has recently been described. This method involves in vivo labeling of glomeruli with cationic ferritin, and then magnetic resonance imaging (MRI) of the ex vivo kidney. Values are obtained in one sixth of the time of disector-based approaches. This new MRI method holds great promise for studies of glomerular number and size ex vivo and in vivo.
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26
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Xie L, Sparks MA, Li W, Qi Y, Liu C, Coffman TM, Johnson GA. Quantitative susceptibility mapping of kidney inflammation and fibrosis in type 1 angiotensin receptor-deficient mice. NMR IN BIOMEDICINE 2013; 26:1853-63. [PMID: 24154952 PMCID: PMC3956055 DOI: 10.1002/nbm.3039] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 08/06/2013] [Accepted: 08/23/2013] [Indexed: 05/18/2023]
Abstract
Disruption of the regulatory role of the kidneys leads to diverse renal pathologies; one major hallmark is inflammation and fibrosis. Conventional magnitude MRI has been used to study renal pathologies; however, the quantification or even detection of focal lesions caused by inflammation and fibrosis is challenging. We propose that quantitative susceptibility mapping (QSM) may be particularly sensitive for the identification of inflammation and fibrosis. In this study, we applied QSM in a mouse model deficient for angiotensin receptor type 1 (AT1). This model is known for graded pathologies, including focal interstitial fibrosis, cortical inflammation, glomerulocysts and inner medullary hypoplasia. We acquired high-resolution MRI on kidneys from AT1-deficient mice that were perfusion fixed with contrast agent. Two MR sequences were used (three-dimensional spin echo and gradient echo) to produce three image contrasts: T1, T2* (magnitude) and QSM. T1 and T2* (magnitude) images were acquired to segment major renal structures and to provide landmarks for the focal lesions of inflammation and fibrosis in the three-dimensional space. The volumes of major renal structures were measured to determine the relationship of the volumes to the degree of renal abnormalities and magnetic susceptibility values. Focal lesions were segmented from QSM images and were found to be closely associated with the major vessels. Susceptibilities were relatively more paramagnetic in wild-type mice: 1.46 ± 0.36 in the cortex, 2.14 ± 0.94 in the outer medulla and 2.10 ± 2.80 in the inner medulla (10(-2) ppm). Susceptibilities were more diamagnetic in knockout mice: -7.68 ± 4.22 in the cortex, -11.46 ± 2.13 in the outer medulla and -7.57 ± 5.58 in the inner medulla (10(-2) ppm). This result was consistent with the increase in diamagnetic content, e.g. proteins and lipids, associated with inflammation and fibrosis. Focal lesions were validated with conventional histology. QSM was very sensitive in detecting pathology caused by small focal inflammation and fibrosis. QSM offers a new MR contrast mechanism to study this common disease marker in the kidney.
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Affiliation(s)
- Luke Xie
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC, USA
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Matthew A. Sparks
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, NC, USA
| | - Wei Li
- Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC, USA
| | - Yi Qi
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Chunlei Liu
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC, USA
- Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC, USA
| | - Thomas M. Coffman
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, NC, USA
| | - G. Allan Johnson
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC, USA
- Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC, USA
- Correspondence to: G. A. Johnson, Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Box 3302, Durham, NC 27710, USA.
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27
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Charlton JR, Beeman SC, Bennett KM. MRI-detectable nanoparticles: the potential role in the diagnosis of and therapy for chronic kidney disease. Adv Chronic Kidney Dis 2013; 20:479-87. [PMID: 24206600 DOI: 10.1053/j.ackd.2013.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 05/23/2013] [Accepted: 06/03/2013] [Indexed: 12/30/2022]
Abstract
Chronic kidney disease (CKD) is a common, deadly, and expensive threat to public health. Patients susceptible to the development of CKD are difficult to identify because there are few noninvasive clinical techniques and markers to assess early kidney dysfunction. Noninvasive imaging techniques are being developed to quantitatively measure kidney morphology and function in preclinical research and in clinical trials. Magnetic resonance imaging (MRI) techniques in particular have the potential to provide structural and functional information in the kidney. Novel molecular imaging techniques, using targeted magnetic nanoparticles that exploit the characteristics of the endogenous protein, ferritin, have been developed in conjunction with MRI to count every perfused glomerulus in the kidney and measure their individual volumes. This technique could open the door to the possibility of prospectively assessing and eventually reducing a patient's risk for progression to CKD. This review highlights the potential clinical benefits of early detection in patients predisposed to CKD and discusses technologic and regulatory hurdles to the translation of these molecular MRI techniques to provide early diagnosis of CKD.
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28
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Bennett KM, Bertram JF, Beeman SC, Gretz N. The emerging role of MRI in quantitative renal glomerular morphology. Am J Physiol Renal Physiol 2013; 304:F1252-7. [PMID: 23515719 DOI: 10.1152/ajprenal.00714.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Techniques to measure morphological parameters, such as glomerular (and thereby nephron) number, glomerular size, and kidney volume, have been vital to understanding factors contributing to chronic kidney disease (CKD). These techniques have also been important to understanding the associations between CKD and other systemic and cardiovascular diseases and have led to the identification of developmental risk factors for these pathologies. However, existing techniques in quantitative kidney morphology are resource- and time-consuming and are destructive to the organ. This review discusses the emerging generation of techniques to study kidney morphology quantitatively using magnetic resonance imaging (MRI) using the intravenous injection of the superparamagnetic nanoparticle cationic ferritin, which binds to the glomerular basement membrane. A primary advantage of MRI over previously established techniques is the ability to quantify morphology in the intact organ with minimal sample preparation. We highlight areas of research where MRI-based morphological measurements will be helpful in animal models and possibly diagnostic clinical nephrology, discuss technical challenges in light of the progress in MRI techniques to date, and identify novel measurements that may be possible using MRI, both ex vivo and in vivo.
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Affiliation(s)
- K M Bennett
- Department of Biology, College of Natural Sciences, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
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Abstract
Toxicology is and will be heavily influenced by advances in many scientific disciplines. For toxicologic pathology, particularly relevant are the increasing array of molecular methods providing deeper insights into toxicity pathways, in vivo imaging techniques visualizing toxicodynamics and more powerful computers anticipated to allow (partly) automated morphological diagnoses. It appears unlikely that, in a foreseeable future, animal studies can be replaced by in silico and in vitro studies or longer term in vivo studies by investigations of biomarkers including toxicogenomics of shorter term studies, though the importance of such approaches will continue to increase. In addition to changes based on scientific progress, the work of toxicopathologists is and will be affected by social and financial factors, among them stagnating budgets, globalization, and outsourcing. The number of toxicopathologists in North America, Europe, and the Far East is not expected to grow. Many toxicopathologists will likely spend less time at the microscope but will be more heavily involved in early research activities, imaging, and as generalists with a broad biological understanding in evaluation and management of toxicity. Toxicologic pathology will remain important and is indispensable for validation of new methods, quality assurance of established methods, and for areas without good alternative methods.
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