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Zhao K, Pohlmann A, Feng Q, Mei Y, Yang G, Yi P, Feng Q, Chen W, Zhou L, Wu EX, Seeliger E, Niendorf T, Feng Y. Physiological system analysis of the kidney by high-temporal-resolution T 2 ∗ monitoring of an oxygenation step response. Magn Reson Med 2020; 85:334-345. [PMID: 32710578 DOI: 10.1002/mrm.28399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/21/2020] [Accepted: 06/08/2020] [Indexed: 11/11/2022]
Abstract
PURPOSE Examine the feasibility of characterizing the regulation of renal oxygenation using high-temporal-resolution monitoring of the T 2 ∗ response to a step-like oxygenation stimulus. METHODS For T 2 ∗ mapping, multi-echo gradient-echo imaging was used (temporal resolution = 9 seconds). A step-like renal oxygenation challenge was applied involving sequential exposure to hyperoxia (100% O2 ), hypoxia (10% O2 + 90% N2 ), and hyperoxia (100% O2 ). In vivo experiments were performed in healthy rats (N = 10) and in rats with bilateral ischemia-reperfusion injury (N = 4). To assess the step response of renal oxygenation, a second-order exponential model was used (model parameters: amplitude [A], time delay [Δt], damping constant [D], and period of the oscillation [T]) for renal cortex, outer stripe of the outer medulla, inner stripe of the outer medulla, and inner medulla. RESULTS The second-order exponential model permitted us to model the exponential T 2 ∗ recovery and the superimposed T 2 ∗ oscillation following renal oxygenation stimulus. The in vivo experiments revealed a difference in Douter medulla between healthy controls (D < 1, indicating oscillatory recovery) and ischemia-reperfusion injury (D > 1, reflecting aperiodic recovery). The increase in Douter medulla by a factor of 3.7 (outer stripe of the outer medulla) and 10.0 (inner stripe of the outer medulla) suggests that this parameter might be rather sensitive to (patho)physiological oxygenation changes. CONCLUSION This study demonstrates the feasibility of monitoring the dynamic oxygenation response of renal tissues to a step-like oxygenation challenge using high-temporal-resolution T 2 ∗ mapping. Our results suggest that the implemented system analysis approach may help to unlock questions regarding regulation of renal oxygenation, with the ultimate goal of providing imaging means for diagnostics and therapy of renal diseases.
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Affiliation(s)
- Kaixuan Zhao
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Qijian Feng
- State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yingjie Mei
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China.,Philips Healthcare, Guangzhou, China
| | - Guixiang Yang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Peiwei Yi
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Qianjin Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Wufang Chen
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Lili Zhou
- State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China
| | - Erdmann Seeliger
- Center for Cardiovascular Research, Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Yanqiu Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
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Kaimori JY, Isaka Y, Hatanaka M, Yamamoto S, Ichimaru N, Fujikawa A, Shibata H, Fujimori A, Miyoshi S, Yokawa T, Kuroda K, Moriyama T, Rakugi H, Takahara S. Diffusion Tensor Imaging MRI With Spin-Echo Sequence and Long-Duration Measurement for Evaluation of Renal Fibrosis in a Rat Fibrosis Model. Transplant Proc 2017; 49:145-152. [DOI: 10.1016/j.transproceed.2016.10.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Wang C, Zhao K, Zhang R, Jiang L, Wang R, Zhang X, Wang H, Jin L, Zhang J, Wang X, Fang J. Evaluation of renal oxygenation change under the influence of carbogen breathing using a dynamic R 2 , R 2 ' and R 2 * quantification approach. NMR IN BIOMEDICINE 2016; 29:1601-1607. [PMID: 27670144 DOI: 10.1002/nbm.3625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 08/03/2016] [Accepted: 08/22/2016] [Indexed: 06/06/2023]
Abstract
The purpose of this study is to demonstrate the feasibility of dynamic renal R2 /R2 '/R2 * measurements based on a method, denoted psMASE-ME, in which a periodic 180° pulse-shifting multi-echo asymmetric spin echo (psMASE) sequence, combined with a moving estimation (ME) strategy, is adopted. Following approval by the institutional animal care and use committee, a block design of respiratory challenge with interleaved air and carbogen (97% O2 , 3% CO2 ) breathing was employed in nine rabbits. Parametrical R2 /R2 '/R2 * maps were computed and average R2 /R2 '/R2 * values were measured in regions of interest in the renal medulla and cortex. Bland-Altman plots showed good agreement between the proposed method and reference standards of multi-echo spin echo and multi-echo gradient echo sequences. Renal R2 , R2 ' and R2 * decreased significantly from 16.2 ± 4.4 s-1 , 9.8 ± 5.2 s-1 and 25.9 ± 5.0 s-1 to 14.9 ± 4.4 s-1 (p < 0.05), 8.5 ± 4.1 s-1 (p < 0.05) and 23.4 ± 4.8 s-1 (p < 0.05) in the cortex when switching the gas mixture from room air to carbogen. In the renal medulla, R2 , R2 ' and R2 * also decreased significantly from 12.9 ± 4.7 s-1 , 15.1 ± 5.8 s-1 and 27.9 ± 5.3 s-1 to 11.8 ± 4.5 s-1 (p < 0.05), 14.2 ± 4.2 s-1 (p < 0.05) and 25.8 ± 5.1 s-1 (p < 0.05). No statistically significant differences in relative R2 , R2 ' and R2 * changes were observed between the cortex and medulla (p = 0.72 for R2 , p = 0.39 for R2 ' and p = 0.61 for R2 *). The psMASE-ME method for dynamic renal R2 /R2 '/R2 * measurements, together with the respiratory challenge, has potential use in the evaluation of renal oxygenation in many renal diseases.
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Affiliation(s)
- Chengyan Wang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Kai Zhao
- Department of Radiology, Peking University First Hospital, Beijing, China
| | - Rui Zhang
- College of Engineering, Peking University, Beijing, China
| | - Li Jiang
- Philips Healthcare, Suzhou, Jiangsu, China
| | - Rui Wang
- Department of Radiology, Peking University First Hospital, Beijing, China
| | - Xiaodong Zhang
- Department of Radiology, Peking University First Hospital, Beijing, China
| | - He Wang
- Philips Healthcare, Suzhou, Jiangsu, China
| | - Lixin Jin
- Philips Healthcare, Suzhou, Jiangsu, China
| | - Jue Zhang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
- College of Engineering, Peking University, Beijing, China.
| | - Xiaoying Wang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
- Department of Radiology, Peking University First Hospital, Beijing, China.
| | - Jing Fang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- College of Engineering, Peking University, Beijing, China
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Jerome NP, Boult JKR, Orton MR, d’Arcy J, Collins DJ, Leach MO, Koh DM, Robinson SP. Modulation of renal oxygenation and perfusion in rat kidney monitored by quantitative diffusion and blood oxygen level dependent magnetic resonance imaging on a clinical 1.5T platform. BMC Nephrol 2016; 17:142. [PMID: 27716094 PMCID: PMC5048450 DOI: 10.1186/s12882-016-0356-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 09/26/2016] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND To investigate the combined use of intravoxel incoherent motion (IVIM) diffusion-weighted (DW) and blood oxygen level dependent (BOLD) magnetic resonance imaging (MRI) to assess rat renal function using a 1.5T clinical platform. METHODS Multiple b-value DW and BOLD MR images were acquired from adult rats using a parallel clinical coil arrangement, enabling quantitation of the apparent diffusion coefficient (ADC), IVIM-derived diffusion coefficient (D), pseudodiffusion coefficient (D*) and perfusion fraction (f), and the transverse relaxation time T2*, for whole kidney, renal cortex, and medulla. Following the acquisition of two baseline datasets to assess measurement repeatability, images were acquired following i.v. administration of hydralazine, furosemide, or angiotensin II for up to 40 min. RESULTS Excellent repeatability (CoV <10 %) was observed for ADC, D, f and T2* measured over the whole kidney. Hydralazine induced a marked and significant (p < 0.05) reduction in whole kidney ADC, D, and T2*, and a significant (p < 0.05) increase in D* and f. Furosemide significantly (p < 0.05) increased whole kidney ADC, D, and T2*. A more variable response to angiotensin II was determined, with a significant (p < 0.05) increase in medulla D* and significant (p < 0.05) reduction in whole kidney T2* established. CONCLUSIONS Multiparametric MRI, incorporating quantitation of IVIM DWI and BOLD biomarkers and performed on a clinical platform, can be used to monitor the acute effects of vascular and tubular modulating drugs on rat kidney function in vivo. Clinical adoption of such functional imaging biomarkers can potentially inform on treatment effects in patients with renal dysfunction.
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Affiliation(s)
- Neil P. Jerome
- Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy & Imaging, The Institute of Cancer Research, London, SM2 5NG UK
| | - Jessica K. R. Boult
- Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy & Imaging, The Institute of Cancer Research, London, SM2 5NG UK
| | - Matthew R. Orton
- Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy & Imaging, The Institute of Cancer Research, London, SM2 5NG UK
| | - James d’Arcy
- Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy & Imaging, The Institute of Cancer Research, London, SM2 5NG UK
| | - David J. Collins
- Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy & Imaging, The Institute of Cancer Research, London, SM2 5NG UK
| | - Martin O. Leach
- Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy & Imaging, The Institute of Cancer Research, London, SM2 5NG UK
| | - Dow-Mu Koh
- Department of Radiology, Royal Marsden NHS Foundation Trust, Sutton, Surrey SM2 5PT UK
| | - Simon P. Robinson
- Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy & Imaging, The Institute of Cancer Research, London, SM2 5NG UK
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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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6
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Zöllner FG, Kalayciyan R, Chacón-Caldera J, Zimmer F, Schad LR. Pre-clinical functional Magnetic Resonance Imaging part I: The kidney. Z Med Phys 2014; 24:286-306. [DOI: 10.1016/j.zemedi.2014.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 05/19/2014] [Accepted: 05/19/2014] [Indexed: 01/10/2023]
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7
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Kim N, Cheema-Dhadli S, Hare GMT, Chong CK, Halperin ML, Kamel KS, Mazer CD. Non-natriuretic doses of furosemide: potential use for decreasing the workload of the renal outer medulla with minimal magnesium wasting in the rat. Nephron Clin Pract 2013; 122:7-12. [PMID: 23548701 DOI: 10.1159/000346741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 12/21/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Since furosemide (FS) inhibits active Na(+) reabsorption by medullary thick ascending limb (mTAL) in the renal outer medulla, it may decrease its work during periods of low O2 supply to deep in the renal outer medulla. This study was designed to demonstrate that there may be a dose of FS would reduce its metabolic work while preventing the excessive loss of magnesium (Mg(2+)). Mg(2+) is important because the ATP needed to perform work must have bound Mg(2+) to it. METHODS Rats were injected intraperitoneally with a range of doses of FS. The measured outcomes were urine flow rate and parameters of functions of the mTAL (i.e. urine and renal papillary osmolality and urinary excretion of Na(+), Cl(-), K(+) and Mg(2+), and concentrations of Mg(2+) in serum). RESULTS The urine flow rate increased significantly starting at 2.4 mg FS/kg. The renal papillary osmolality decreased at ≥0.4 mg FS/kg, and the large detectable natriuresis started at 1.6 mg FS/kg. At this latter dose, the urinary excretion of Mg(2+) rose significantly. CONCLUSION In rats, the non-natriuretic dose of FS may reduce the work of the mTAL. The earliest indicator of reduced work in the mTAL appears to be a decrease in urine osmolality rather than a rise in urine flow rate. Higher doses of FS should be avoided, as they induce high rates of Mg(2+) excretion, which can deplete the body of this essential electrolyte.
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Affiliation(s)
- Namhee Kim
- Department of Anesthesia, Division of Nephrology, University of Toronto, St. Michael's Hospital, Keenan Research Centre in the Li Ka Shing Knowledge Institute, Toronto, Ont., Canada
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8
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Pohlmann A, Hentschel J, Fechner M, Hoff U, Bubalo G, Arakelyan K, Cantow K, Seeliger E, Flemming B, Waiczies H, Waiczies S, Schunck WH, Dragun D, Niendorf T. High temporal resolution parametric MRI monitoring of the initial ischemia/reperfusion phase in experimental acute kidney injury. PLoS One 2013; 8:e57411. [PMID: 23468984 PMCID: PMC3585384 DOI: 10.1371/journal.pone.0057411] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Accepted: 01/21/2013] [Indexed: 12/12/2022] Open
Abstract
Ischemia/reperfusion (I/R) injury, a consequence of kidney hypoperfusion or temporary interruption of blood flow is a common cause of acute kidney injury (AKI). There is an unmet need to better understand the mechanisms operative during the initial phase of ischemic AKI. Non-invasive in vivo parametric magnetic resonance imaging (MRI) may elucidate spatio-temporal pathophysiological changes in the kidney by monitoring the MR relaxation parameters T2* and T2, which are known to be sensitive to blood oxygenation. The aim of our study was to establish the technical feasibility of fast continuous T2*/T2 mapping throughout renal I/R. MRI was combined with a remotely controlled I/R model and a segmentation model based semi-automated quantitative analysis. This technique enabled the detailed assessment of in vivo changes in all kidney regions during ischemia and early reperfusion. Significant changes in T2* and T2 were observed shortly after induction of renal ischemia and during the initial reperfusion phase. Our study demonstrated for the first time that continuous and high temporal resolution parametric MRI is feasible for in-vivo monitoring and characterization of I/R induced AKI in rats. This technique may help in the identification of the timeline of key events responsible for development of renal damage in hypoperfusion-induced AKI.
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Affiliation(s)
- Andreas Pohlmann
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
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Donati OF, Nanz D, Serra AL, Boss A. Quantitative BOLD response of the renal medulla to hyperoxic challenge at 1.5 T and 3.0 T. NMR IN BIOMEDICINE 2012; 25:1133-1138. [PMID: 22290729 DOI: 10.1002/nbm.2781] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 12/23/2011] [Accepted: 12/23/2011] [Indexed: 05/31/2023]
Abstract
The aim of this study was to gage the magnitude of changes of the apparent renal medullary transverse relaxation time (ΔT(2)) induced by inhalation of pure oxygen (O(2) ) or carbogen (95% O(2) , 5% CO(2) ) versus baseline breathing of room air. Eight healthy volunteers underwent 2D multi-gradient echo MR imaging at 1.5 T and 3.0 T. Parametrical T(2) relaxation time maps were computed and average T(2) was measured in regions of interest placed in the renal medulla and cortex. The largest T(2) changes were measured in the renal medulla, with a relative ∆T(2) of 33.8 ± 22.0% (right medulla) and 34.7 ± 17.6% (left medulla) as compared to room air for oxygen breathing (p > 0.01), and 53.8 ± 23.9% and 53.5 ± 33.9% (p < 0.01) for carbogen breathing, respectively at 3 T. At 1.5 T, the corresponding values were 13.7 ± 18.5% and 24.1 ± 17.1% (p < 0.01) for oxygen breathing and 23.9 ± 17.2% and 38.9 ± 37.6% (p < 0.01) for carbogen breathing. As a result, we showed that renal medullary T(2) times responded strongly to inhalation of hyperoxic gases, which may be attributed to the hypoxic condition of the medulla and subsequent reduction in deoxyhemoglobin.
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Affiliation(s)
- Olivio F Donati
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland.
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Matsushita T, Kusakabe Y, Kitamura A, Okada S, Murase K. Protective effect of hydrogen-rich water against gentamicin-induced nephrotoxicity in rats using blood oxygenation level-dependent MR imaging. Magn Reson Med Sci 2012; 10:169-76. [PMID: 21959999 DOI: 10.2463/mrms.10.169] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE We assessed intrarenal oxygenation in gentamicin-induced nephrotoxicity (GIN) and the protective effect of hydrogen-rich water (HW) against GIN using blood oxygenation level-dependent magnetic resonance (MR) imaging. MATERIALS AND METHODS We acquired T(2)*-weighted images (T(2)*WI) of 21 rats on Days 0, 2, 4, and 7 using a 1.5-tesla MR imaging system. The rats were divided into 3 groups of seven each: control rats had free access to standard water and no gentamicin (GM) injection; rats designated the GM group had free access to standard water and were injected with GM (80 mg/kg/day) subcutaneously for 7 days; and the third group, designated the GM+HW group, had free access to HW and were injected with GM. R(2)* (=1/T(2)*) was estimated from T(2)*WI. RESULTS R(2)* values in the cortex were significantly decreased on Days 2, 4, and 7 compared with those on Day 0 in the GM group but not significantly changed in the control and GM+HW groups. R(2)* values in the medulla did not change significantly in any group. CONCLUSIONS Our findings suggested reduced oxygen utility, mainly in the cortex, in gentamicin-induced nephrotoxicity and an ameliorative effect of hydrogen-rich water against GIN.
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Affiliation(s)
- Taro Matsushita
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan
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Roller J, Laschke MW, Tschernig T, Schramm R, Veith NT, Thorlacius H, Menger MD. How to detect a dwarf: in vivo imaging of nanoparticles in the lung. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2011; 7:753-62. [PMID: 21419874 DOI: 10.1016/j.nano.2011.02.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 02/10/2011] [Accepted: 02/24/2011] [Indexed: 11/30/2022]
Abstract
UNLABELLED Nanotechnology is a rapidly developing field in science and industry. The exposure to nanoparticles (NPs) will steadily grow in the future and there is thus an urgent need to study potential impacts of the interaction between NPs and the human body. The respiratory tract is the route of entry for all accidentally inhaled NPs. Moreover, NPs may intentionally be delivered into the lung as contrast agents and drug delivery systems. The present review provides an overview of currently used techniques for the in vivo imaging of NPs in the lung, including x-ray imaging, computed tomography, gamma camera imaging, positron emission tomography, magnetic resonance imaging, near-infrared imaging, and intravital fluorescence microscopy. Studies based on these techniques may contribute to the development of novel NP-based drug delivery systems and contrast agents. In addition, they may provide completely new insights into nanotoxicological processes. FROM THE CLINICAL EDITOR Nanoparticles are rapidly gaining ground in various therapeutic and diagnostic applications. This review provides an overview of current in vivo imaging techniques of NPs in the lung, including x-ray, CT, gamma camera imaging, PET, MRI, near-infrared imaging, and intravital fluorescence microscopy, aiding the development of novel NP-based techniques and nanotoxicology.
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Affiliation(s)
- Jonas Roller
- Institute for Clinical & Experimental Surgery, University of Saarland, Homburg/Saar, Germany.
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