51
|
Spinner GR, von Deuster C, Tezcan KC, Stoeck CT, Kozerke S. Bayesian intravoxel incoherent motion parameter mapping in the human heart. J Cardiovasc Magn Reson 2017; 19:85. [PMID: 29110717 PMCID: PMC5770136 DOI: 10.1186/s12968-017-0391-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 10/04/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Intravoxel incoherent motion (IVIM) imaging of diffusion and perfusion in the heart suffers from high parameter estimation error. The purpose of this work is to improve cardiac IVIM parameter mapping using Bayesian inference. METHODS A second-order motion-compensated diffusion weighted spin-echo sequence with navigator-based slice tracking was implemented to collect cardiac IVIM data in early systole in eight healthy subjects on a clinical 1.5 T CMR system. IVIM data were encoded along six gradient optimized directions with b-values of 0-300 s/mm2. Subjects were scanned twice in two scan sessions one week apart to assess intra-subject reproducibility. Bayesian shrinkage prior (BSP) inference was implemented to determine IVIM parameters (diffusion D, perfusion fraction F and pseudo-diffusion D*). Results were compared to least-squares (LSQ) parameter estimation. Signal-to-noise ratio (SNR) requirements for a given fitting error were assessed for the two methods using simulated data. Reproducibility analysis of parameter estimation in-vivo using BSP and LSQ was performed. RESULTS BSP resulted in reduced SNR requirements when compared to LSQ in simulations. In-vivo, BSP analysis yielded IVIM parameter maps with smaller intra-myocardial variability and higher estimation certainty relative to LSQ. Mean IVIM parameter estimates in eight healthy subjects were (LSQ/BSP): 1.63 ± 0.28/1.51 ± 0.14·10-3 mm2/s for D, 13.13 ± 19.81/13.11 ± 5.95% for F and 201.45 ± 313.23/13.11 ± 14.53·10-3 mm2/s for D ∗. Parameter variation across all volunteers and measurements was lower with BSP compared to LSQ (coefficient of variation BSP vs. LSQ: 9% vs. 17% for D, 45% vs. 151% for F and 111% vs. 155% for D ∗). In addition, reproducibility of the IVIM parameter estimates was higher with BSP compared to LSQ (Bland-Altman coefficients of repeatability BSP vs. LSQ: 0.21 vs. 0.26·10-3 mm2/s for D, 5.55 vs. 6.91% for F and 15.06 vs. 422.80·10-3 mm2/s for D*). CONCLUSION Robust free-breathing cardiac IVIM data acquisition in early systole is possible with the proposed method. BSP analysis yields improved IVIM parameter maps relative to conventional LSQ fitting with fewer outliers, improved estimation certainty and higher reproducibility. IVIM parameter mapping holds promise for myocardial perfusion measurements without the need for contrast agents.
Collapse
Affiliation(s)
- Georg R Spinner
- Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland.
| | - Constantin von Deuster
- Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland
| | - Kerem C Tezcan
- Computer Vision Laboratory, ETH Zurich, Sternwartstrasse 7, 8092, Zurich, Switzerland
| | - Christian T Stoeck
- Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland
| |
Collapse
|
52
|
Federau C. Intravoxel incoherent motion MRI as a means to measure in vivo perfusion: A review of the evidence. NMR IN BIOMEDICINE 2017; 30. [PMID: 28885745 DOI: 10.1002/nbm.3780] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/19/2017] [Accepted: 07/07/2017] [Indexed: 05/07/2023]
Abstract
The idea that in vivo intravoxel incoherent motion magnetic resonance signal is influenced by blood motion in the microvasculature is exciting, because it suggests that local and quantitative perfusion information can be obtained in a simple and elegant way from a few diffusion-weighted images, without contrast injection. When the method was proposed in the late 1980s some doubts appeared as to its feasibility, and, probably because the signal to noise and image quality at the time was not sufficient, no obvious experimental evidence could be produced to alleviate them. Helped by the tremendous improvements seen in the last three decades in MR hardware, pulse design, and post-processing capabilities, an increasing number of encouraging reports on the value of intravoxel incoherent motion perfusion imaging have emerged. The aim of this article is to review the current published evidence on the feasibility of in vivo perfusion imaging with intravoxel incoherent motion MRI.
Collapse
Affiliation(s)
- Christian Federau
- Division of Diagnostic and Interventional Neuroradiology, Department of Radiology, University Hospital Basel, Petersgraben, Basle, Switzerland
| |
Collapse
|
53
|
Wang Y, Zhang H, Zhang R, Zhao Z, Xu Z, Wang L, Liu R, Gao F. Investigation of aquaporins and apparent diffusion coefficient from ultra-high b-values in a rat model of diabetic nephropathy. Eur Radiol Exp 2017; 1:13. [PMID: 29708187 PMCID: PMC5909346 DOI: 10.1186/s41747-017-0016-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/12/2017] [Indexed: 02/05/2023] Open
Abstract
Background To assess kidney damage in a rat model of type-2 diabetic nephropathy based on apparent diffusion coefficient (ADC) data obtained from ultra-high b-values and discuss its relationship to the expression of aquaporins (AQPs). Methods This study was approved by the institutional Animal Care and Use Committee. Thirty male Sprague-Dawley rats were randomised into two groups: (1) untreated controls and (2) diabetes mellitus (DM). All rats underwent diffusion-weighted imaging (DWI) with 18 b-values (0–4500 s/mm2). Maps of low ADC (ADClow), standard ADC (ADCst) and ultra-high ADC (ADCuh) were calculated from low b-values (0–200 s/mm2), standard b-values (300–1500 s/mm2) and ultra-high b-values (1700–4500 s/mm2), respectively. The expression of AQPs in the kidneys was studied using immunohistochemistry. Laboratory parameters of diabetic and kidney functions, ADClow, ADCst, ADCuh, and the optical density (OD) of AQP expression in the two groups were compared using an independent t test. Correlations between ADCs and the OD of AQP expression were evaluated by Pearson’s correlation analysis. Results ADCuh were significantly higher in the cortex (CO), outer stripe of the outer medulla (OS) and inner stripe of the outer medulla (IS), and the OD values of AQ-2 were significantly higher in the OS, IS and inner medulla (IM) in DM animals compared with control animals. ADCuh and OD values of AQP-2 expression were positively correlated in the OS, IS and IM of the kidney. Conclusions ADCuh may work as useful metrics for early detection of kidney damage in diabetic nephropathy and may be associated with AQP-2 expression.
Collapse
Affiliation(s)
- Yu Wang
- 1Department of Radiology, West China Hospital of Sichuan University, No. 37, Guoxue Lane outside the south, Wuhou District Chengdu, China
| | - Heng Zhang
- 1Department of Radiology, West China Hospital of Sichuan University, No. 37, Guoxue Lane outside the south, Wuhou District Chengdu, China
| | - Ruzhi Zhang
- 1Department of Radiology, West China Hospital of Sichuan University, No. 37, Guoxue Lane outside the south, Wuhou District Chengdu, China
| | - Zhoushe Zhao
- General Electronic Company Healthcare (China), Beijing, China
| | - Ziqian Xu
- 1Department of Radiology, West China Hospital of Sichuan University, No. 37, Guoxue Lane outside the south, Wuhou District Chengdu, China
| | - Lei Wang
- 1Department of Radiology, West China Hospital of Sichuan University, No. 37, Guoxue Lane outside the south, Wuhou District Chengdu, China
| | - Rongbo Liu
- 1Department of Radiology, West China Hospital of Sichuan University, No. 37, Guoxue Lane outside the south, Wuhou District Chengdu, China
| | - Fabao Gao
- 1Department of Radiology, West China Hospital of Sichuan University, No. 37, Guoxue Lane outside the south, Wuhou District Chengdu, China
| |
Collapse
|
54
|
Clinical Robustness of Accelerated and Optimized Abdominal Diffusion-Weighted Imaging. Invest Radiol 2017; 52:590-595. [DOI: 10.1097/rli.0000000000000370] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
55
|
Cox EF, Buchanan CE, Bradley CR, Prestwich B, Mahmoud H, Taal M, Selby NM, Francis ST. Multiparametric Renal Magnetic Resonance Imaging: Validation, Interventions, and Alterations in Chronic Kidney Disease. Front Physiol 2017; 8:696. [PMID: 28959212 PMCID: PMC5603702 DOI: 10.3389/fphys.2017.00696] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 08/30/2017] [Indexed: 12/15/2022] Open
Abstract
Background: This paper outlines a multiparametric renal MRI acquisition and analysis protocol to allow non-invasive assessment of hemodynamics (renal artery blood flow and perfusion), oxygenation (BOLD T2*), and microstructure (diffusion, T1 mapping). Methods: We use our multiparametric renal MRI protocol to provide (1) a comprehensive set of MRI parameters [renal artery and vein blood flow, perfusion, T1, T2*, diffusion (ADC, D, D*, fp), and total kidney volume] in a large cohort of healthy participants (127 participants with mean age of 41 ± 19 years) and show the MR field strength (1.5 T vs. 3 T) dependence of T1 and T2* relaxation times; (2) the repeatability of multiparametric MRI measures in 11 healthy participants; (3) changes in MRI measures in response to hypercapnic and hyperoxic modulations in six healthy participants; and (4) pilot data showing the application of the multiparametric protocol in 11 patients with Chronic Kidney Disease (CKD). Results: Baseline measures were in-line with literature values, and as expected, T1-values were longer at 3 T compared with 1.5 T, with increased T1 corticomedullary differentiation at 3 T. Conversely, T2* was longer at 1.5 T. Inter-scan coefficients of variation (CoVs) of T1 mapping and ADC were very good at <2.9%. Intra class correlations (ICCs) were high for cortex perfusion (0.801), cortex and medulla T1 (0.848 and 0.997 using SE-EPI), and renal artery flow (0.844). In response to hypercapnia, a decrease in cortex T2* was observed, whilst no significant effect of hyperoxia on T2* was found. In CKD patients, renal artery and vein blood flow, and renal perfusion was lower than for healthy participants. Renal cortex and medulla T1 was significantly higher in CKD patients compared to healthy participants, with corticomedullary T1 differentiation reduced in CKD patients compared to healthy participants. No significant difference was found in renal T2*. Conclusions: Multiparametric MRI is a powerful technique for the assessment of changes in structure, hemodynamics, and oxygenation in a single scan session. This protocol provides the potential to assess the pathophysiological mechanisms in various etiologies of renal disease, and to assess the efficacy of drug treatments.
Collapse
Affiliation(s)
- Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Christopher R Bradley
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Benjamin Prestwich
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Huda Mahmoud
- Centre for Kidney Research and Innovation, Royal Derby Hospital, University of NottinghamDerby, United Kingdom
| | - Maarten Taal
- Centre for Kidney Research and Innovation, Royal Derby Hospital, University of NottinghamDerby, United Kingdom
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, Royal Derby Hospital, University of NottinghamDerby, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| |
Collapse
|
56
|
Kurugol S, Marami B, Afacan O, Warfield SK, Gholipour A. Motion-Robust Spatially Constrained Parameter Estimation in Renal Diffusion-Weighted MRI by 3D Motion Tracking and Correction of Sequential Slices. MOLECULAR IMAGING, RECONSTRUCTION AND ANALYSIS OF MOVING BODY ORGANS, AND STROKE IMAGING AND TREATMENT : FIFTH INTERNATIONAL WORKSHOP, CMMI 2017, SECOND INTERNATIONAL WORKSHOP, RAMBO 2017, AND FIRST INTERNATIONAL WORKSHOP, SWITCH 2017, ... 2017; 10555:75-85. [PMID: 29457154 DOI: 10.1007/978-3-319-67564-0_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In this work, we introduce a novel motion-robust spatially constrained parameter estimation (MOSCOPE) technique for kidney diffusion-weighted MRI. The proposed motion compensation technique does not require a navigator, trigger, or breath-hold but only uses the intrinsic features of the acquired data to track and compensate for motion to reconstruct precise models of the renal diffusion signal. We have developed a technique for physiological motion tracking based on robust state estimation and sequential registration of diffusion sensitized slices acquired within 200ms. This allows a sampling rate of 5Hz for state estimation in motion tracking that is sufficiently faster than both respiratory and cardiac motion rates in children and adults, which range between 0.8 to 0.2Hz, and 2.5 to 1Hz, respectively. We then apply the estimated motion parameters to data from each slice and use motion-compensated data for 1) robust intra-voxel incoherent motion (IVIM) model estimation in the kidney using a spatially constrained model fitting approach, and 2) robust weighted least squares estimation of the diffusion tensor model. Experimental results, including precision of IVIM model parameters using bootstrap-sampling and in-vivo whole kidney tractography, showed significant improvement in precision and accuracy of these models using the proposed method compared to models based on the original data and volumetric registration.
Collapse
Affiliation(s)
- Sila Kurugol
- Dept. of Radiology, Boston Children's Hospital and Harvard Medical School
| | - Bahram Marami
- Dept. of Radiology, Boston Children's Hospital and Harvard Medical School
| | - Onur Afacan
- Dept. of Radiology, Boston Children's Hospital and Harvard Medical School
| | - Simon K Warfield
- Dept. of Radiology, Boston Children's Hospital and Harvard Medical School
| | - Ali Gholipour
- Dept. of Radiology, Boston Children's Hospital and Harvard Medical School
| |
Collapse
|
57
|
Poynton CB, Lee MM, Li Y, Laszik Z, Worters PW, Mackenzie JD, Courtier J. Intravoxel incoherent motion analysis of renal allograft diffusion with clinical and histopathological correlation in pediatric kidney transplant patients: A preliminary cross-sectional observational study. Pediatr Transplant 2017; 21. [PMID: 28653457 DOI: 10.1111/petr.12996] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/09/2017] [Indexed: 02/06/2023]
Abstract
The purpose of this study was to compare IVIM values in pediatric renal transplants with histopathology and clinical management change. Fifteen pediatric renal transplant recipients (mean 15.7±2.9 years) were prospectively scanned on a 3T MR scanner with multi-b DTI, prior to same-day transplant biopsy. IVIM maps from 14 subjects were analyzed (one excluded due to motion). Mean values were computed from cortical ROIs and medullary ROIs corresponding to the biopsy site. Subjects were also grouped according to whether or not the biopsy resulted in a change in clinical management. Cortico-medullary IVIM estimates and histopathologic Banff scores were correlated with KT. Cortico-medullary IVIM differences between the "change" and "no change" groups was compared with Mann-Whitney U test. Cortical Dp showed significant moderate negative correlation with Banff t and ci scores (KT=-0.497, P=.035 and KT=-0.46, P=.046) and moderate positive correlation with Banff i score (KT=0.527, P=.028). Cortical Pf showed significant moderate correlation with ci and ct scores (KT=0.489, P=.035 and KT=0.457, P=.043). Tissue diffusivity, Dt , estimated with IVIM was significantly different between the "change" and "no change" groups in medullary ROIs (U=6, P=.021). IVIM analysis has potential as a noninvasive biomarker in assessment of pediatric renal allograft pathology.
Collapse
Affiliation(s)
- Clare B Poynton
- Department of Radiology and Biomedical Imaging, UCSF Benioff Children's Hospital, San Francisco, CA, USA
| | - Marsha M Lee
- Department of Pediatrics, Division of Pediatric Nephrology, UCSF Benioff Children's Hospital, San Francisco, CA, USA
| | - Yi Li
- Department of Radiology and Biomedical Imaging, UCSF Benioff Children's Hospital, San Francisco, CA, USA
| | - Zoltan Laszik
- Department of Pathology, UCSF Benioff Children's Hospital, San Francisco, CA, USA
| | - Pauline W Worters
- Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, USA
| | - John D Mackenzie
- Department of Radiology and Biomedical Imaging, UCSF Benioff Children's Hospital, San Francisco, CA, USA
| | - Jesse Courtier
- Department of Radiology and Biomedical Imaging, UCSF Benioff Children's Hospital, San Francisco, CA, USA
| |
Collapse
|
58
|
Morrell GR, Zhang JL, Lee VS. Magnetic Resonance Imaging of the Fibrotic Kidney. J Am Soc Nephrol 2017; 28:2564-2570. [PMID: 28784699 DOI: 10.1681/asn.2016101089] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Magnetic resonance imaging (MRI) has been used for many years for anatomic evaluation of the kidney. Recently developed methods attempt to go beyond anatomy to give information about the health and function of the kidneys. Several methods, including diffusion-weighted MRI, renal blood oxygen level-dependent MRI, renal MR elastography, and renal susceptibility imaging, show promise for providing unique insight into kidney function and severity of fibrosis. However, substantial limitations in accuracy and practicality limit the immediate clinical application of each method. Further development and improvement are necessary to achieve the ideal of a noninvasive image-based measure of renal fibrosis. Our brief review provides a short explanation of these emerging MRI methods and outlines the promising initial results obtained with each as well as current limitations and barriers to clinical implementation.
Collapse
Affiliation(s)
- Glen R Morrell
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah
| | - Jeff L Zhang
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah
| | - Vivian S Lee
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah
| |
Collapse
|
59
|
van Baalen S, Leemans A, Dik P, Lilien MR, ten Haken B, Froeling M. Intravoxel incoherent motion modeling in the kidneys: Comparison of mono-, bi-, and triexponential fit. J Magn Reson Imaging 2017; 46:228-239. [PMID: 27787931 PMCID: PMC5484284 DOI: 10.1002/jmri.25519] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/07/2016] [Indexed: 02/03/2023] Open
Abstract
PURPOSE To evaluate if a three-component model correctly describes the diffusion signal in the kidney and whether it can provide complementary anatomical or physiological information about the underlying tissue. MATERIALS AND METHODS Ten healthy volunteers were examined at 3T, with T2 -weighted imaging, diffusion tensor imaging (DTI), and intravoxel incoherent motion (IVIM). Diffusion tensor parameters (mean diffusivity [MD] and fractional anisotropy [FA]) were obtained by iterative weighted linear least squares fitting of the DTI data and mono-, bi-, and triexponential fit parameters (D1 , D2 , D3 , ffast2 , ffast3 , and finterm ) using a nonlinear fit of the IVIM data. Average parameters were calculated for three regions of interest (ROIs) (cortex, medulla, and rest) and from fiber tractography. Goodness of fit was assessed with adjusted R2 ( Radj2) and the Shapiro-Wilk test was used to test residuals for normality. Maps of diffusion parameters were also visually compared. RESULTS Fitting the diffusion signal was feasible for all models. The three-component model was best able to describe fast signal decay at low b values (b < 50), which was most apparent in Radj2 of the ROI containing high diffusion signals (ROIrest ), which was 0.42 ± 0.14, 0.61 ± 0.11, 0.77 ± 0.09, and 0.81 ± 0.08 for DTI, one-, two-, and three-component models, respectively, and in visual comparison of the fitted and measured S0 . None of the models showed significant differences (P > 0.05) between the diffusion constant of the medulla and cortex, whereas the ffast component of the two and three-component models were significantly different (P < 0.001). CONCLUSION Triexponential fitting is feasible for the diffusion signal in the kidney, and provides additional information. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:228-239.
Collapse
Affiliation(s)
- Sophie van Baalen
- MIRA Institute for Biomedical Technology and Technical MedicineUniversity of TwenteEnschedeThe Netherlands
| | - Alexander Leemans
- Image Sciences InstituteUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Pieter Dik
- Department of Pediatric UrologyWilhelmina Children's Hospital, UMC UtrechtUtrechtThe Netherlands
| | - Marc R. Lilien
- Department of Pediatric NephrologyWilhelmina Children's Hospital, UMC UtrechtUtrechtThe Netherlands
| | - Bennie ten Haken
- MIRA Institute for Biomedical Technology and Technical MedicineUniversity of TwenteEnschedeThe Netherlands
| | - Martijn Froeling
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| |
Collapse
|
60
|
Wells JA, Thomas DL, Saga T, Kershaw J, Aoki I. MRI of cerebral micro-vascular flow patterns: A multi-direction diffusion-weighted ASL approach. J Cereb Blood Flow Metab 2017; 37:2076-2083. [PMID: 27461904 PMCID: PMC5464702 DOI: 10.1177/0271678x16660985] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The study and clinical assessment of brain disease is currently hindered by a lack of non-invasive methods for the detailed and accurate evaluation of cerebral vascular pathology. Angiography can detect aberrant flow in larger feeding arteries/arterioles but cannot resolve the micro-vascular network. Small vessels are a key site of vascular pathology that can lead to haemorrhage and infarction, which may in turn trigger or exacerbate neurodegenerative processes. In this study, we describe a method to investigate microvascular flow anisotropy using a hybrid arterial spin labelling and multi-direction diffusion-weighted MRI sequence. We present evidence that the technique is sensitive to the mean/predominant direction of microvascular flow in localised regions of the rat cortex. The data provide proof of principle for a novel and non-invasive imaging tool to investigate cerebral micro-vascular flow patterns in healthy and disease states.
Collapse
Affiliation(s)
- J A Wells
- 1 National Institute of Radiological Sciences (NIRS), National Institute for Quantum and Radiological Science and Technology (QST), Chiba, Japan.,2 UCL Centre for Advanced Biomedical Imaging, University College London, London, UK
| | - D L Thomas
- 3 Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, UK.,4 Leonard Wolfson Experimental Neurology Centre, UCL Institute of Neurology, London, UK
| | - T Saga
- 1 National Institute of Radiological Sciences (NIRS), National Institute for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - J Kershaw
- 1 National Institute of Radiological Sciences (NIRS), National Institute for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - I Aoki
- 1 National Institute of Radiological Sciences (NIRS), National Institute for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| |
Collapse
|
61
|
van Eijs MJM, van Zuilen AD, de Boer A, Froeling M, Nguyen TQ, Joles JA, Leiner T, Verhaar MC. Innovative Perspective: Gadolinium-Free Magnetic Resonance Imaging in Long-Term Follow-Up after Kidney Transplantation. Front Physiol 2017; 8:296. [PMID: 28559850 PMCID: PMC5432553 DOI: 10.3389/fphys.2017.00296] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/24/2017] [Indexed: 12/23/2022] Open
Abstract
Since the mid-1980s magnetic resonance imaging (MRI) has been investigated as a non- or minimally invasive tool to probe kidney allograft function. Despite this long-standing interest, MRI still plays a subordinate role in daily practice of transplantation nephrology. With the introduction of new functional MRI techniques, administration of exogenous gadolinium-based contrast agents has often become unnecessary and true non-invasive assessment of allograft function has become possible. This raises the question why application of MRI in the follow-up of kidney transplantation remains restricted, despite promising results. Current literature on kidney allograft MRI is mainly focused on assessment of (sub) acute kidney injury after transplantation. The aim of this review is to survey whether MRI can provide valuable diagnostic information beyond 1 year after kidney transplantation from a mechanistic point of view. The driving force behind chronic allograft nephropathy is believed to be chronic hypoxia. Based on this, techniques that visualize kidney perfusion and oxygenation, scarring, and parenchymal inflammation deserve special interest. We propose that functional MRI mechanistically provides tools for diagnostic work-up in long-term follow-up of kidney allografts.
Collapse
Affiliation(s)
- Mick J M van Eijs
- Department of Nephrology and Hypertension, University Medical Center UtrechtUtrecht, Netherlands
| | - Arjan D van Zuilen
- Department of Nephrology and Hypertension, University Medical Center UtrechtUtrecht, Netherlands
| | - Anneloes de Boer
- Department of Radiology, University Medical Center UtrechtUtrecht, Netherlands
| | - Martijn Froeling
- Department of Radiology, University Medical Center UtrechtUtrecht, Netherlands
| | - Tri Q Nguyen
- Department of Pathology, University Medical Center UtrechtUtrecht, Netherlands
| | - Jaap A Joles
- Department of Nephrology and Hypertension, University Medical Center UtrechtUtrecht, Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Center UtrechtUtrecht, Netherlands
| | - Marianne C Verhaar
- Department of Nephrology and Hypertension, University Medical Center UtrechtUtrecht, Netherlands
| |
Collapse
|
62
|
The IVIM signal in the healthy cerebral gray matter: A play of spherical and non-spherical components. Neuroimage 2017; 152:340-347. [DOI: 10.1016/j.neuroimage.2017.03.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 02/27/2017] [Accepted: 03/02/2017] [Indexed: 12/12/2022] Open
|
63
|
Pilot Study of Renal Diffusion Tensor Imaging as a Correlate to Histopathology in Pediatric Renal Allografts. AJR Am J Roentgenol 2017; 208:1358-1364. [PMID: 28379715 DOI: 10.2214/ajr.16.17418] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Fractional anisotropy (FA) is a measure of molecular motion obtained from diffusion tensor imaging (DTI). The objective of this study was to assess the use of FA as a noninvasive correlate of renal allograft histopathology. SUBJECTS AND METHODS Sixteen pediatric renal allograft recipients were imaged using DTI in a prospective study, between October 2014 and January 2016, before a same-day renal allograft biopsy. The Kendall tau correlation coefficient was used to assess the relationship between cortical and medullary FA values and several clinically important Banff renal allograft histopathology scores. The Mann-Whitney U test was also used to compare cortical and medullary FA values in the region of biopsy in patients whose biopsy results did and in those whose biopsy results did not change clinical management. RESULTS Medullary FA values had direct inverse correlation with several histopathology scores: tubulitis (designated "t" score in Banff pathologic classification, p < 0.04), interstitial inflammation (i score, p < 0.005), tubular atrophy (ct score, p < 0.002), and interstitial fibrosis (ci score, p < 0.007). Cortical FA values inversely correlated with peritubular capillaritis (ptc score, p < 0.02). Neither medullary nor cortical FA values correlated with glomerulitis (g score). At a b value of 800 s/mm2, medullary FA values of pediatric renal allograft recipients whose renal biopsies prompted a change in clinical management (mean ± SD at a b value of 800 s/mm2 = 0.262 ± 0.07; n = 9) were statistically different compared with the group whose biopsy results did not change clinical management (mean ± SD at a b value of 800 s/mm2 = 0.333 ± 0.06; n = 7) (p < 0.006). CONCLUSION FA is a noninvasive correlate of several important renal allograft histopathology scores and a potential noninvasive method of assessing renal allograft health in pediatric allograft recipients.
Collapse
|
64
|
Lanzman RS, Wittsack HJ. Diffusion tensor imaging in abdominal organs. NMR IN BIOMEDICINE 2017; 30:e3434. [PMID: 26556181 DOI: 10.1002/nbm.3434] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 09/18/2015] [Accepted: 09/20/2015] [Indexed: 06/05/2023]
Abstract
Initially, diffusion tensor imaging (DTI) was mainly applied in studies of the human brain to analyse white matter tracts. As DTI is outstanding for the analysis of tissue´s microstructure, the interest in DTI for the assessment of abdominal tissues has increased continuously in recent years. Tissue characteristics of abdominal organs differ substantially from those of the human brain. Further peculiarities such as respiratory motion and heterogenic tissue composition lead to difficult conditions that have to be overcome in DTI measurements. Thus MR measurement parameters have to be adapted for DTI in abdominal organs. This review article provides information on the technical background of DTI with a focus on abdominal imaging, as well as an overview of clinical studies and application of DTI in different abdominal regions. Copyright © 2015 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Rotem Shlomo Lanzman
- Medical Faculty, Department of Diagnostic and Interventional Radiology, University of Dusseldorf, Dusseldorf, Germany
| | - Hans-Jörg Wittsack
- Medical Faculty, Department of Diagnostic and Interventional Radiology, University of Dusseldorf, Dusseldorf, Germany
| |
Collapse
|
65
|
Hilbert F, Bock M, Neubauer H, Veldhoen S, Wech T, Bley TA, Köstler H. An intravoxel oriented flow model for diffusion-weighted imaging of the kidney. NMR IN BIOMEDICINE 2016; 29:1403-1413. [PMID: 27488570 DOI: 10.1002/nbm.3584] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 06/06/2016] [Accepted: 06/21/2016] [Indexed: 06/06/2023]
Abstract
By combining intravoxel incoherent motion (IVIM) and diffusion tensor imaging (DTI) we introduce a new diffusion model called intravoxel oriented flow (IVOF) that accounts for anisotropy of diffusion and the flow-related signal. An IVOF model using a simplified apparent flow fraction tensor (IVOFf ) is applied to diffusion-weighted imaging of human kidneys. The kidneys of 13 healthy volunteers were examined on a 3 T scanner. Diffusion-weighted images were acquired with six b values between 0 and 800 s/mm(2) and 30 diffusion directions. Diffusivity and flow fraction were calculated for different diffusion models. The Akaike information criterion was used to compare the model fit of the proposed IVOFf model to IVIM and DTI. In the majority of voxels the proposed IVOFf model with a simplified apparent flow fraction tensor performs better than IVIM and DTI. Mean diffusivity is significantly higher in DTI compared with models that account for the flow-related signal. The fractional anisotropy of diffusion is significantly reduced when flow fraction is considered to be anisotropic. Anisotropy of the apparent flow fraction tensor is significantly higher in the renal medulla than in the cortex region. The IVOFf model describes diffusion-weighted data in the human kidney more accurately than IVIM or DTI. The apparent flow fraction in the kidney proved to be anisotropic.
Collapse
Affiliation(s)
- Fabian Hilbert
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany.
| | - Maximilian Bock
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Henning Neubauer
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Simon Veldhoen
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Tobias Wech
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Herbert Köstler
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| |
Collapse
|
66
|
Kim M, Kim HS. Emerging Techniques in Brain Tumor Imaging: What Radiologists Need to Know. Korean J Radiol 2016; 17:598-619. [PMID: 27587949 PMCID: PMC5007387 DOI: 10.3348/kjr.2016.17.5.598] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 05/03/2016] [Indexed: 12/11/2022] Open
Abstract
Among the currently available brain tumor imaging, advanced MR imaging techniques, such as diffusion-weighted MR imaging and perfusion MR imaging, have been used for solving diagnostic challenges associated with conventional imaging and for monitoring the brain tumor treatment response. Further development of advanced MR imaging techniques and postprocessing methods may contribute to predicting the treatment response to a specific therapeutic regimen, particularly using multi-modality and multiparametric imaging. Over the next few years, new imaging techniques, such as amide proton transfer imaging, will be studied regarding their potential use in quantitative brain tumor imaging. In this review, the pathophysiologic considerations and clinical validations of these promising techniques are discussed in the context of brain tumor characterization and treatment response.
Collapse
Affiliation(s)
- Minjae Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Ho Sung Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| |
Collapse
|
67
|
De Luca A, Bertoldo A, Froeling M. Effects of perfusion on DTI and DKI estimates in the skeletal muscle. Magn Reson Med 2016; 78:233-246. [PMID: 27538923 DOI: 10.1002/mrm.26373] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/28/2016] [Accepted: 07/18/2016] [Indexed: 12/20/2022]
Abstract
PURPOSE In this study, we evaluated the effects of perfusion of the skeletal muscle on diffusion tensor imaging (DTI) and diffusional kurtosis imaging (DKI) parameters and their reproducibility. METHODS Diffusion tensor imaging and DKI models, with and without intravoxel incoherent motion (IVIM) correction, were applied to simulated data at different physiological conditions and signal-to-noise ratio levels. Next, the same models were applied to data of the right calf of five healthy volunteers, acquired twice at 3 telsa. For six muscles, we evaluated the correlation of the perfusion signal fraction, with parameters derived from DTI and DKI, and performed repeatability analysis with and without IVIM correction. Additionally, the IVIM correction was compared to a multishell acquisition approach that minimizes perfusion effects on DTI estimates. RESULTS Simulations and acquired data showed that DTI and DKI estimates were biased proportionally to the perfusion signal fraction, and that IVIM correction was needed for accurate estimation of the DTI and DKI parameters. However, taking perfusion into account did not improve repeatability. CONCLUSION Blood perfusion has an effect on DTI and DKI estimations, but it can be minimized with IVIM correction or multishell acquisition strategies. Magn Reson Med 78:233-246, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Alberto De Luca
- Department of Information Engineering, University of Padova, Padova, Italy.,Department of Radiology, University Medical Center, Utrecht, The Netherlands.,Neuroimaging Lab, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, LC, Italy
| | | | - Martijn Froeling
- Department of Radiology, University Medical Center, Utrecht, The Netherlands
| |
Collapse
|
68
|
Iima M, Le Bihan D. Clinical Intravoxel Incoherent Motion and Diffusion MR Imaging: Past, Present, and Future. Radiology 2016; 278:13-32. [PMID: 26690990 DOI: 10.1148/radiol.2015150244] [Citation(s) in RCA: 348] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The concept of diffusion magnetic resonance (MR) imaging emerged in the mid-1980s, together with the first images of water diffusion in the human brain, as a way to probe tissue structure at a microscopic scale, although the images were acquired at a millimetric scale. Since then, diffusion MR imaging has become a pillar of modern clinical imaging. Diffusion MR imaging has mainly been used to investigate neurologic disorders. A dramatic application of diffusion MR imaging has been acute brain ischemia, providing patients with the opportunity to receive suitable treatment at a stage when brain tissue might still be salvageable, thus avoiding terrible handicaps. On the other hand, it was found that water diffusion is anisotropic in white matter, because axon membranes limit molecular movement perpendicularly to the nerve fibers. This feature can be exploited to produce stunning maps of the orientation in space of the white matter tracts and brain connections in just a few minutes. Diffusion MR imaging is now also rapidly expanding in oncology, for the detection of malignant lesions and metastases, as well as monitoring. Water diffusion is usually largely decreased in malignant tissues, and body diffusion MR imaging, which does not require any tracer injection, is rapidly becoming a modality of choice to detect, characterize, or even stage malignant lesions, especially for breast or prostate cancer. After a brief summary of the key methodological concepts beyond diffusion MR imaging, this article will give a review of the clinical literature, mainly focusing on current outstanding issues, followed by some innovative proposals for future improvements.
Collapse
Affiliation(s)
- Mami Iima
- From the Department of Diagnostic Imaging and Nuclear Medicine (M.I.) and the Human Brain Research Center (D.L.B.), Kyoto University Graduate School of Medicine, and the Hakubi Center for Advanced Research (M.I.), Kyoto University, Kyoto, Japan; and NeuroSpin, CEA/DSV/I2BM, Bât 145, Point Courrier 156, CEA-Saclay Center, F-91191 Gif-sur-Yvette, France (D.L.B.)
| | - Denis Le Bihan
- From the Department of Diagnostic Imaging and Nuclear Medicine (M.I.) and the Human Brain Research Center (D.L.B.), Kyoto University Graduate School of Medicine, and the Hakubi Center for Advanced Research (M.I.), Kyoto University, Kyoto, Japan; and NeuroSpin, CEA/DSV/I2BM, Bât 145, Point Courrier 156, CEA-Saclay Center, F-91191 Gif-sur-Yvette, France (D.L.B.)
| |
Collapse
|
69
|
Ren T, Wen CL, Chen LH, Xie SS, Cheng Y, Fu YX, Oesingmann N, de Oliveira A, Zuo PL, Yin JZ, Xia S, Shen W. Evaluation of renal allografts function early after transplantation using intravoxel incoherent motion and arterial spin labeling MRI. Magn Reson Imaging 2016; 34:908-14. [PMID: 27114341 DOI: 10.1016/j.mri.2016.04.022] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 03/25/2016] [Accepted: 04/17/2016] [Indexed: 12/30/2022]
Abstract
PURPOSE To evaluate renal allografts function early after transplantation using intravoxel incoherent motion (IVIM) and arterial spin labeling (ASL) MRI. METHODS This prospective study was approved by the local ethics committee, and written informed consent was obtained from all participants. A total of 82 participants with 62 renal allograft recipients (2-4weeks after kidney transplantation) and 20 volunteers were enrolled to be scanned using IVIM and ASL MRI on a 3.0T MR scanner. Recipients were divided into two groups with either normal or impaired function according to the estimated glomerular filtration rate (eGFR) with a threshold of 60ml/min/1.73m(2). The apparent diffusion coefficient (ADC) of pure diffusion (ADCslow), the ADC of pseudodiffusion (ADCfast), perfusion fraction (PF), and renal blood flow (RBF) of cortex were compared among three groups. The correlation of ADCslow, ADCfast, PF and RBF with eGFR was evaluated. The receiver operating characteristic (ROC) curve and binary logistic regression analyses were performed to assess the diagnostic efficiency of using IVIM and ASL parameters to discriminate allografts with impaired function from normal function. P<0.05 was considered statistically significant. RESULTS In allografts with normal function, no significant difference of mean cortical ADCslow, ADCfast, and PF was found compared with healthy controls (P>0.05). Cortical RBF in allografts with normal function was statistically lower than that of healthy controls (P<0.001). Mean cortical ADCslow, ADCfast, PF and RBF were lower for allografts with impaired function than that with normal function (P<0.05). Mean cortical ADCslow, ADCfast, PF and RBF showed a positive correlation with eGFR (all P<0.01) for recipients. The combination of IVIM and ASL MRI showed a higher area under the ROC curve (AUC) (0.865) than that of ASL MRI alone (P=0.02). CONCLUSION Combined IVIM and ASL MRI can better evaluate the diffusion and perfusion properties for allografts early after kidney transplantation.
Collapse
Affiliation(s)
- Tao Ren
- Department of Radiology, Tianjin Medical University First Center Hospital, 300192, Tianjin, China.
| | - Cheng-Long Wen
- Department of Radiology, Tianjin Medical University First Center Hospital, 300192, Tianjin, China.
| | - Li-Hua Chen
- Department of Radiology, Tianjin Medical University First Center Hospital, 300192, Tianjin, China.
| | - Shuang-Shuang Xie
- Department of Radiology, Tianjin Medical University First Center Hospital, 300192, Tianjin, China.
| | - Yue Cheng
- Department of Radiology, Tianjin Medical University First Center Hospital, 300192, Tianjin, China.
| | - Ying-Xin Fu
- Department of Transplantation Surgery, Tianjin First Center Hospital, 300192, Tianjin, China.
| | | | | | - Pan-Li Zuo
- Siemens Healthcare, MR Collaborations NE Asia, 100010,Beijing, China.
| | - Jian-Zhong Yin
- Department of Radiology, Tianjin Medical University First Center Hospital, 300192, Tianjin, China.
| | - Shuang Xia
- Department of Radiology, Tianjin Medical University First Center Hospital, 300192, Tianjin, China.
| | - Wen Shen
- Department of Radiology, Tianjin Medical University First Center Hospital, 300192, Tianjin, China.
| |
Collapse
|
70
|
Intravoxel incoherent motion analysis of abdominal organs: computation of reference parameters in a large cohort of C57Bl/6 mice and correlation to microvessel density. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 29:751-63. [DOI: 10.1007/s10334-016-0540-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 02/19/2016] [Accepted: 02/22/2016] [Indexed: 12/30/2022]
|
71
|
Ye Q, Chen Z, Zhao Y, Zhang Z, Miao H, Xiao Q, Wang M, Li J. Initial experience of generalized intravoxel incoherent motion imaging and diffusion tensor imaging (GIVIM-DTI) in healthy subjects. J Magn Reson Imaging 2016; 44:732-8. [PMID: 27079733 DOI: 10.1002/jmri.25262] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 03/18/2016] [Indexed: 11/06/2022] Open
Affiliation(s)
- Qiong Ye
- Department of Radiology; The First Affiliated Hospital of Wenzhou Medical University; ZheJiang P.R. China
| | - Zhongwei Chen
- Department of Radiology; The First Affiliated Hospital of Wenzhou Medical University; ZheJiang P.R. China
| | - Youfan Zhao
- Department of Radiology; The First Affiliated Hospital of Wenzhou Medical University; ZheJiang P.R. China
| | - Zhenhua Zhang
- Department of Radiology; The First Affiliated Hospital of Wenzhou Medical University; ZheJiang P.R. China
| | - Haiwei Miao
- Department of Radiology; The First Affiliated Hospital of Wenzhou Medical University; ZheJiang P.R. China
| | - Qinqin Xiao
- Department of Radiology; The First Affiliated Hospital of Wenzhou Medical University; ZheJiang P.R. China
| | - Meihao Wang
- Department of Radiology; The First Affiliated Hospital of Wenzhou Medical University; ZheJiang P.R. China
| | - Jiance Li
- Department of Radiology; The First Affiliated Hospital of Wenzhou Medical University; ZheJiang P.R. China
| |
Collapse
|
72
|
Abstract
PURPOSE OF REVIEW Over the past decade, a variety of MRI methods have been developed and applied to many kidney diseases. These MRI techniques show great promise, enabling the noninvasive assessment of renal structure, function and injury in individuals. This review will highlight the current applications of functional MRI techniques for the assessment of renal disease and discuss future directions. RECENT FINDINGS Many pathological (functional and structural) changes or factors in renal disease can be assessed by advanced MRI techniques. These include renal vascular structure and function (contrast-enhanced MRI, arterial spin labelling), tissue oxygenation (blood oxygen level dependent MRI), renal tissue injury and fibrosis (diffusion or magnetization transfer imaging, magnetic resonance elastography), renal metabolism (chemical exchange saturation transfer, spectroscopic imaging), nephron endowment (cationic-contrast imaging), sodium concentration (23Na-MRI) and molecular events (targeted-contrast imaging). SUMMARY Current advances in MRI techniques have enabled the noninvasive investigation of renal disease. Further development, evaluation and application of the MRI techniques should facilitate better understanding and assessment of renal disease, and the development of new imaging biomarkers, enabling the intensified treatment of high-risk populations and a more rapid interrogation of novel therapeutic agents and protocols.
Collapse
|
73
|
Seif M, Mani LY, Lu H, Boesch C, Reyes M, Vogt B, Vermathen P. Diffusion tensor imaging of the human kidney: Does image registration permit scanning without respiratory triggering? J Magn Reson Imaging 2016; 44:327-34. [PMID: 26871263 DOI: 10.1002/jmri.25176] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/19/2016] [Indexed: 12/20/2022] Open
Abstract
PURPOSE To investigate if image registration of diffusion tensor imaging (DTI) allows omitting respiratory triggering for both transplanted and native kidneys MATERIALS AND METHODS Nine kidney transplant recipients and eight healthy volunteers underwent renal DTI on a 3T scanner with and without respiratory triggering. DTI images were registered using a multimodal nonrigid registration algorithm. Apparent diffusion coefficient (ADC), the contribution of perfusion (FP ), and the fractional anisotropy (FA) were determined. Relative root mean square errors (RMSE) of the fitting and the standard deviations of the derived parameters within the regions of interest (SDROI ) were evaluated as quality criteria. RESULTS Registration significantly reduced RMSE in all DTI-derived parameters of triggered and nontriggered measurements in cortex and medulla of both transplanted and native kidneys (P < 0.05 for all). In addition, SDROI values were lower with registration for all 16 parameters in transplanted kidneys (14 of 16 SDROI values were significantly reduced, P < 0.04) and for 15 of 16 parameters in native kidneys (9 of 16 SDROI values were significantly reduced, P < 0.05). Comparing triggered versus nontriggered DTI in transplanted kidneys revealed no significant difference for RMSE (P > 0.14) and for SDROI (P > 0.13) of all parameters. In contrast, in native kidneys relative RMSE from triggered scans were significantly lower than those from nontriggered scans (P < 0.02), while SDROI was slightly higher in triggered compared to nontriggered measurements in 15 out of 16 comparisons (significantly for two, P < 0.05). CONCLUSION Registration improves the quality of DTI in native and transplanted kidneys. Diffusion parameters in renal allografts can be measured without respiratory triggering. In native kidneys, respiratory triggering appears advantageous. J. Magn. Reson. Imaging 2016;44:327-334.
Collapse
Affiliation(s)
- Maryam Seif
- Department of Clinical Research and Radiology, University of Bern, Bern, Switzerland
| | - Laila Yasmin Mani
- Department of Nephrology, Hypertension and Clinical Pharmacology, University Hospital of Bern, Switzerland
| | - Huanxiang Lu
- Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland
| | - Chris Boesch
- Department of Clinical Research and Radiology, University of Bern, Bern, Switzerland
| | - Mauricio Reyes
- Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland
| | - Bruno Vogt
- Department of Nephrology, Hypertension and Clinical Pharmacology, University Hospital of Bern, Switzerland
| | - Peter Vermathen
- Department of Clinical Research and Radiology, University of Bern, Bern, Switzerland
| |
Collapse
|
74
|
Lanzman RS, Notohamiprodjo M, Wittsack HJ. [Functional magnetic resonance imaging of the kidneys]. Radiologe 2015; 55:1077-87. [PMID: 26628260 DOI: 10.1007/s00117-015-0044-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Interest in functional renal magnetic resonance imaging (MRI) has significantly increased in recent years. This review article provides an overview of the most important functional imaging techniques and their potential clinical applications for assessment of native and transplanted kidneys, with special emphasis on the clarification of renal tumors.
Collapse
|
75
|
Kuai ZX, Liu WY, Zhang YL, Zhu YM. Generalization of intravoxel incoherent motion model by introducing the notion of continuous pseudodiffusion variable. Magn Reson Med 2015; 76:1594-1603. [DOI: 10.1002/mrm.26064] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 10/29/2015] [Accepted: 10/29/2015] [Indexed: 12/24/2022]
Affiliation(s)
- Zi-Xiang Kuai
- International Associated Laboratory (LIA)-CNRS Medical Engineering and Theory in Image and Signal Laboratory (Metislab), Harbin Institute of Technology (HIT); Harbin China
- CREATIS, CNRS (UMR 5220); INSERM (U1044); INSA Lyon; Universite de Lyon; Villeurbanne France
| | - Wan-Yu Liu
- International Associated Laboratory (LIA)-CNRS Medical Engineering and Theory in Image and Signal Laboratory (Metislab), Harbin Institute of Technology (HIT); Harbin China
| | - Yan-Li Zhang
- International Associated Laboratory (LIA)-CNRS Medical Engineering and Theory in Image and Signal Laboratory (Metislab), Harbin Institute of Technology (HIT); Harbin China
| | - Yue-Min Zhu
- International Associated Laboratory (LIA)-CNRS Medical Engineering and Theory in Image and Signal Laboratory (Metislab), Harbin Institute of Technology (HIT); Harbin China
- CREATIS, CNRS (UMR 5220); INSERM (U1044); INSA Lyon; Universite de Lyon; Villeurbanne France
| |
Collapse
|
76
|
Yuan M, Zhang YD, Zhu C, Yu TF, Shi HB, Shi ZF, Li H, Wu JF. Comparison of intravoxel incoherent motion diffusion-weighted MR imaging with dynamic contrast-enhanced MRI for differentiating lung cancer from benign solitary pulmonary lesions. J Magn Reson Imaging 2015; 43:669-79. [PMID: 26340144 DOI: 10.1002/jmri.25018] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Revised: 07/09/2015] [Accepted: 07/10/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND To compare intravoxel incoherent motion (IVIM) and pharmacokinetic analysis dynamic contrast-enhanced MR imaging (DCE-MRI) in distinguishing lung cancer (LC) from benign solitary pulmonary lesions (SPL). METHODS This prospective study was approved by the institutional review board, and written informed consent was obtained. Eighty-one consecutive patients considered for SPL underwent DW-IVIM and DCE-3T MRI. ADC, D, D*, and f were calculated with mono- and bi-exponential models. K(trans) , kep , ve , and vp were calculated with the modified Tofts model. Receiver operating characteristic (ROC) analysis was constructed to determine the diagnostic performance of IVIM and DCE-MRI in discriminating LC from benignity. RESULTS There were 29 patients with a total of 48 benign SPL and 52 LCs: 4 small cell carcinomas (SCLC), 19 squamous cell carcinomas (SCC), and 29 adenocarcinomas (Adeno-Ca). Both Adeno-Ca (ADC: 1.19 ± 0.23 × 10(-3) mm(2) /s; D:1.12 ± 0.35 × 10(-3) mm(2) /s; ve :0.27 ± 0.13; K(trans) :0.24 ± 0.09 min(-1) ; kep :0.90 ± 0.45 min(-1) ) and SCC (1.13± 0.28 × 10(-3) mm(2) /s; 1.02 ± 0.32 10(-3) mm(2) /s; 0.32 ± 0.14; 0.26 ± 0.08 min(-1) ; 0.90 ± 0.48 min(-1) ) had significantly lower ADC, D, ve and larger K(trans) , kep than benignity (1.37 ± 0.38 × 10(-3) mm(2) /s; 1.34 ± 0.45 × 10(-3) mm(2) /s; 0.42 ± 0.19; 0.19 ± 0.08 min(-1) ; 0.53 ± 0.26 min(-1) ). D (72.2%) had significantly higher accuracy (72.2%) and higher sensitivity (91.3%) than other imaging indices (accuracy: 55.5-68.0%; sensitivity: 41.3-78.3%; all P < 0.01) except for accuracy in kep (70.8%; P > 0.05) in discriminating LC from benignity. K(trans) exhibited significantly higher specificity (84.6%) than the other indices (38.5-73.1%; P < 0.01). These results can be improved by combined D and K(trans) , leading to a sensitivity, specificity and accuracy of 94.2%, 92%, and 93.5%, respectively. CONCLUSION IVIM-derived D and DCE-derived K(trans) are two promising parameters for differentiating LC from benignity.
Collapse
Affiliation(s)
- Mei Yuan
- Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yu-Dong Zhang
- Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Chan Zhu
- Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Tong-Fu Yu
- Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Hai-Bin Shi
- Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zhao-Fei Shi
- Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Hai Li
- Department of Pathology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jiang-Fen Wu
- Department of Biomedical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| |
Collapse
|
77
|
Fan WJ, Ren T, Li Q, Zuo PL, Long MM, Mo CB, Chen LH, Huang LX, Shen W. Assessment of renal allograft function early after transplantation with isotropic resolution diffusion tensor imaging. Eur Radiol 2015; 26:567-75. [PMID: 26017738 DOI: 10.1007/s00330-015-3841-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 05/02/2015] [Accepted: 05/11/2015] [Indexed: 01/21/2023]
Abstract
OBJECTIVES To investigate the value of diffusion tensor imaging (DTI) and tractography in renal allografts at the early stage after kidney transplantation. METHODS This study was approved by the institutional ethical review committee, and written informed consent was obtained. A total of 54 renal allograft recipients 2-3 weeks after transplantation and 26 age-matched healthy volunteers underwent renal DTI with a 3.0-T magnetic resonance imaging (MRI) system. Recipients were divided into three groups according to the estimated glomerular filtration rate (eGFR). Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the cortex and medulla were measured and compared among the groups. Whole-kidney tractography was performed. Correlation of eGFR with diffusion parameters was evaluated. RESULTS In allografts with stable function, the medullary ADC was higher and the cortical FA was lower (p < 0.001) than in healthy kidneys. The cortical ADC, medullary ADC and FA decreased as the allograft function declined, and with a positive correlation with eGFR (p < 0.001); cortical FA did not. Tractography demonstrated a decrease of tract density in impaired functional allografts. CONCLUSIONS Renal DTI produces reliable results to assess renal allograft function at the early stage after transplantation. KEY POINTS • DTI and tractography can evaluate renal allograft function at an early stage • Medullary FA, cortical and medullary ADC can effectively evaluate allograft function • Medullary FA, cortical and medullary ADC are correlated with eGFR in renal allografts • Medullary ADC increased and cortical FA decreased in stable allografts compared to control subjects • Medullary FA, cortical and medullary ADC decreased and allograft function declined.
Collapse
Affiliation(s)
- Wen-jun Fan
- Department of Radiology, Tianjin Medical University First Central Hospital, Tianjin, 300192, China.,Medical Department, Armed Police Corps Hospital of Henan Province, Zhengzhou, 450052, China
| | - Tao Ren
- Department of Radiology, Tianjin Medical University First Central Hospital, Tianjin, 300192, China
| | - Qiong Li
- Department of Radiology, Tianjin Medical University First Central Hospital, Tianjin, 300192, China
| | - Pan-li Zuo
- Siemens Healthcare, MR Collaboration NE Asia, Beijing, 100102, China
| | - Miao-miao Long
- Department of Radiology, Tianjin Medical University First Central Hospital, Tianjin, 300192, China
| | - Chun-bai Mo
- Department of Transplantation Surgery, Tianjin First Central Hospital, Tianjin, 300192, China
| | - Li-hua Chen
- Department of Radiology, Tianjin Medical University First Central Hospital, Tianjin, 300192, China
| | - Li-xiang Huang
- Department of Radiology, Tianjin Medical University First Central Hospital, Tianjin, 300192, China
| | - Wen Shen
- Department of Radiology, Tianjin Medical University First Central Hospital, Tianjin, 300192, China.
| |
Collapse
|
78
|
Zhang Z, Yuan Q, Zhou H, Zhao D, Li L, Gerberich JL, Mason RP. Assessment of tumor response to oxygen challenge using quantitative diffusion MRI in an animal model. J Magn Reson Imaging 2015; 42:1450-7. [PMID: 25866057 DOI: 10.1002/jmri.24914] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/26/2015] [Accepted: 03/27/2015] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To assess tumor response to oxygen challenge using quantitative diffusion magnetic resonance imaging (MRI). MATERIALS AND METHODS A well-characterized Dunning R3327-AT1 rat prostate cancer line was implanted subcutaneously in the right thigh of male Copenhagen rats (n = 8). Diffusion-weighted images (DWI) with multiple b values (0, 25, 50, 100, 150, 200, 300, 500, 1000, 1500 s/mm(2) ) in three orthogonal directions were obtained using a multishot FSE-based Stejskal-Tanner DWI sequence (FSE-DWI) at 4.7T, while rats breathed medical air (21% oxygen) and with 100% oxygen challenge. Stretched-exponential and intravoxel incoherent motion (IVIM) models were used to calculate and compare quantitative diffusion parameters: diffusion heterogeneity index (α), intravoxel distribution of diffusion coefficients (DDC), tissue diffusivity (Dt), pseudo-diffusivity (Dp), and perfusion fraction (f) on a voxel-by-voxel basis. RESULTS A significant increase of α (73.9 ± 4.7% in air vs. 78.1 ± 4.5% in oxygen, P = 0.0198) and a significant decrease of f (13.4 ± 3.7% in air vs. 10.4 ± 2.7% in oxygen, P = 0.0201) were observed to accompany oxygen challenge. Correlations between f and α during both air and oxygen breathing were found; the correlation coefficients (r) were -0.90 and -0.96, respectively. Positive correlations between Dt and DDC with oxygen breathing (r = 0.95, P = 0.0003), f and DDC with air breathing were also observed (r = 0.95, P = 0.0004). CONCLUSION Quantitative diffusion MRI demonstrated changes in tumor perfusion in response to oxygen challenge.
Collapse
Affiliation(s)
- Zhongwei Zhang
- Department of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Qing Yuan
- Department of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Heling Zhou
- Department of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Dawen Zhao
- Department of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Li Li
- Department of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA
| | | | - Ralph P Mason
- Department of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|