Renal MRI
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Tuesday 8 May 2012
Room 219-220  16:00 - 18:00 Moderators: Masoom A. Haider, Diego R. Martin

16:00 0335.   Introduction
Diego Martin
16:12 0336.   
Serial effects of iodinated contrast media on the renal hemodynamics and oxygenation as evaluated by ASL and BOLD MRI
Jing Wang1, Yudong Zhang2, Xuedong Yang2, Xiaoying Wang2, Jue Zhang1,3, and Jing Fang1,3
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, 2Department of Radiology, Peking University First Hospital, Beijing, China, 3College of Engineering, Peking University, Beijing, China

Contrast media is associated with several adverse effects, including contrast-induced nephropathy. We utilized noninvasive ASL and BOLD MRI to evaluate the serial effects of intravenous-injected iodinated CM on rabbit renal hemodynamics and oxygenation. Both FAIR-ASL and multiple-echo SPGR sequences were performed 24 hours before and 1, 24, 48 and 72 hours after injection to obtain serial renal blood flow and relative spin-spin relaxation rate (R2*). Iopamidol is associated with a relatively longer-term hypoperfusion in whole kidney and decreased oxygen level in the inner stripes of the outer medulla.

16:24 0337.   
Temporally-resolved imaging of renal sodium-23 changes after furosemid injection
Raffi Kalayciyan1, Friedrich Wetterling1, Sabine Neudecker2, Norbert Gretz2, and Lothar R. Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, 2Medical Research Center, Heidelberg University, Mannheim, Germany

Since renal function is highly correlated with renal tissue 23Na concentration, 23Na-Kidney-MRI can be used to monitor the spatial changes in 23Na along the corticomedullary axis after diuretics administration. Furthermore, the temporal changes in the medulla and cortex 23Na signals could be studied, if sufficient spatial and temporal resolution can be achieved. The aim of this study was to measure the temporal 23Na signal before and after furosemide-injection in four rats via bilateral renal 23Na-MRI (n=8). In order to maximize 23Na signal at 9.4 T, a 3D-Ultrashort Echo Time (3D-UTE) sequence was used in conjunction with a home-built transceiver surface resonator.

16:36 0338.   
Evaluating Endothelial Damage in Acute Kidney Injury with Perfluorocarbon (PFC) Nanoparticles (NP) and 19F MRI
Lingzhi Hu1, Junjie Chen1, Xiaoxia Yang1, Shelton D. Caruthers1, Gregory M. Lanza1, and Samuel A. Wickline1
1Washington University School of Medicine, saint louis, MO, United States

We have demonstrated a new 19F MRI approach using circulating PFC NP to quantify renal perfusion and vascular damage after ischemic injury. The measured regional intrarenal blood volume and oxygenation is consistent with previous observations. In I/R injured kidney, 19F MRI of PFC NP delineates reduced blood volume in C-M junction and vascular leakage in medulla as a consequence of endothelial damage. Although BOLD MRI shows enhanced T2* values at C-M junction of injured kidneys, it does not necessarily reflect hyperoxia but may also sense reduced blood flow. Thus, the proposed novel 19F MRI approach could provide a powerful tool to assess renal vascular damage in AKI.

16:48 0339.   Advanced MRI methods for the differentiation and characterization of acute and chronic kidney diseases in mice
Zohar Milman1, Jonathan Axelrod1, Samuel Heyman2, Nathalie Corchia-Nachmanson1, and Rinat Abramovitch1
1The Goldyne Savad Institute of Gene Therapy, Hadassah Hebrew University Medical Center, Jerusalem, Israel, 2Department of Medicine, Hadassah Hebrew University Medical Center, Jerusalem, Israel

The use of MRI for the diagnosis of acute and chronic kidney diseases is expanding; however, contrast-enhanced methods are limited due to adverse effects. We studied the feasibility of two MRI-methods: (1) HRI, based on BOLD fMRI, combined with hypercapnic and hyperoxic challenges, for monitoring changes in kidney perfusion, and (2) True-FISP, for monitoring changes in renal morphology, during CKD and AKI progression in mice. True-FISP images revealed clear differences in CKD compared to AKI. HRI maps revealed significantly reduced renal perfusion in both CKD and AKI. Together, these methods may assist in the differentiation and characterization of renal pathologies.

17:00 0340.   
Magnetic resonance BOLD and diffusion tensor imaging for diagnosis of histopathological changes in a rat model of diabetic nephropathy permission withheld
Katja Hueper1, Dagmar Hartung1, Marcel Gutberlet1, Faikah Gueler2, Holger Sann3, Bettina Husen3, Frank Wacker1, and Dania Reiche3
1Radiology, Hannover Medical School, Hannover, Germany, 2Nephrology, Hannover Medical School, Hannover, Germany, 3Abbott Products GmbH, Hannover, Germany

We investigated whether MR BOLD and diffusion tensor imaging (DTI) enables detection of renal pathologies in a rat model of diabetic nephropathy. Twenty-one rats (control; diabetes; diabetes with uninephrectomy, DM UNX) were examined by BOLD and echoplanar DTI (1.5T, b=0, 300 s/mm2, 6 diffusion directions). T2*-values, Fractional Anisotropy (FA) and ADC were compared to laboratory parameters and histology. T2*-values were not different between groups. However, in kidneys of DM UNX rats FA was significantly reduced and inversely correlated with glomerulosclerosis, interstitial fibrosis and tubular damage. Thus, MR DTI might be useful to noninvasively identify and monitor renal impairment in diabetes.

17:12 0341.   
Longitudinal Measurement of Renal Oxygenation and Perfusion in Donor-Recipient Pairs Using BOLD and ASL MRI
David J Niles1, Nathan S Artz1, Elizabeth A Sadowski2, Arjang Djamali3, Thomas M Grist1,2, and Sean B Fain1,2
1Medical Physics, University of Wisconsin, Madison, WI, United States, 2Radiology, University of Wisconsin, Madison, WI, United States, 3Medicine, University of Wisconsin, Madison, WI, United States

Routine monitoring of renal function following transplantation is important for early detection of disease. In this study we used BOLD and ASL MRI to measure renal oxygenation and perfusion, respectively, in matched pairs of kidney transplant donors and recipients up to two years following transplantation. Statistically significant decreases in cortical perfusion and medullary oxygenation were observed in transplanted kidneys 3 months post-transplantation and remained present one year post-transplantation. Further measurements in this ongoing study will be used to statistically assess function two years post-transplantation.

17:24 0342.   Renal Susceptibility Imaging in AT1 Deficient Mice
Luke Xie1,2, Wei Li3, Matthew Sparks4, Yi Qi2, Gary P. Cofer2, Thomas Coffman4, G. A. Johnson1,2, and Chunlei Liu2,3
1Biomedical Engineering, Duke University, Durham, NC, United States, 2Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, 3Radiology, Duke University Medical Center, Durham, NC, United States, 4Nephrology, Duke University Medical Center, Durham, NC, United States

This study utilizes the first renal susceptibility imaging on altered kidneys in mice lacking angiotensin II receptor AT1A or both AT1A and AT1B receptors. Kidneys were imaged using a GRE sequence at 9.4 T and susceptibility values were measured in cortex, outer medulla, and inner medulla for comparison in wild type (WT), AT1a -/- (A), and AT1a -/- AT1b -/- (AB) mice. AB kidneys exhibited interstitial fibrosis, tubular atrophy, and arterial thickening, which changed the spatial distribution of paramagnetic contrast for magnetic susceptibility. AB kidneys exhibited low contrast regions/vessels, higher susceptibility, and broader distribution compared to WT or A kidneys.

17:36 0343.   Pathological tissue classification by multiparametric MRI: Technical Development and Application in Renal Masses Characterisation.
Rado Andriantsimiavona1, Dow-Mu Koh1, David Collins1, Simon Doran1, and Martin Leach1
1Institute of Cancer Research UK, Sutton, London, United Kingdom

We have developed an interactive framework that allows spatially synchronised 3D visualisation and analysis of anatomical, diffusion-weighted and dynamic contrast enhanced MR data in multi-planar orientations and used it to establish correlations between parametric maps derived from MRI (ADC and AUC) and the corresponding characteristics measured from paired histological sections. Our aim is to provide biologically meaningful interpretations of multiparametric analysis as well as build a computer aided tissue classification scheme for the RCC model.

17:48 0344.   Combined Diffusion-weighted-, Blood oxygen level dependent- and Dynamic contrast enhanced-MRI for assessment of renal cell carcinoma.
Mike Notohamiprodjo1, Michael Staehler2, Nicole Steiner1, Felix Schwab3, Steven P Sourbron4, Henrik J Michaely5, Maximilian F Reiser1, and Konstantin Nikolaou1
1Department of Clinical Radiology, University Hospitals Munich, Munich, Bavaria, Germany, 2Clinic for Urology, University Hospitals Munich, 3Department of Clinical Radiology, Josef Lissner Institute for Biomedical Imaging, University Hospitals Munich, Munich, Bavaria, Germany, 4Medical Physics, University of Leeds, 5Department of Clinical Radiology and Nuclear Medicine, University Hospital Mannheim

Multiple MR-techniques for functional tumor evaluation are available, however correlation of these techniques has not been investigated. A protocol comprising Diffusion weighted Imaging (DWI), Blood oxygen level dependent (BOLD) and Dynamic contrast enhanced (DCE)-MRI is feasible for assessment of primary RCC. BOLD moderately correlates to perfusion derived from DCE-MRI. ADC shows moderate correlation to the extracellular volume, but does not correlate to tumor oxygenation or perfusion as it provides mixed information on both perfusion and cellularity. IVIM analysis may resolve this ambiguity. Tumor permeability does not correlate to any other functional parameter.