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Zhang JL, Morrell G, Rusinek H, Sigmund EE, Chandarana H, Lerman LO, Prasad PV, Niles D, Artz N, Fain S. New magnetic resonance imaging methods in nephrology. Kidney Int. 2014;85:768-778. [PMID: 24067433 PMCID: PMC3965662 DOI: 10.1038/ki.2013.361] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 02/06/2023]
Abstract
Established as a method to study anatomic changes, such as renal tumors or atherosclerotic vascular disease, magnetic resonance imaging (MRI) to interrogate renal function has only recently begun to come of age. In this review, we briefly introduce some of the most important MRI techniques for renal functional imaging, and then review current findings on their use for diagnosis and monitoring of major kidney diseases. Specific applications include renovascular disease, diabetic nephropathy, renal transplants, renal masses, acute kidney injury and pediatric anomalies. With this review, we hope to encourage more collaboration between nephrologists and radiologists to accelerate the development and application of modern MRI tools in nephrology clinics.
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Goldfarb JW, Arnold S, Roth M. Gadolinium pharmacokinetics of chronic myocardial infarcts: Implications for late gadolinium-enhanced infarct imaging. J Magn Reson Imaging 2009; 30:763-70. [PMID: 19787722 DOI: 10.1002/jmri.21901] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To monitor gadolinium pharmacokinetics in the hearts of patients with chronic myocardial infarcts and to determine the variability of contrast agent concentrations and accuracy of infarct detection over an hour time period. MATERIALS AND METHODS Twenty-five patients with chronic myocardial infarcts were examined. T1 measurements were performed every 2 minutes using an inversion recovery CINE balanced steady-state free precession technique. Paired differences in T1 values over time for the discrimination between the left ventricular (LV) bloodpool, viable, and infarct myocardium were statistically evaluated. The average change per 1, 5, and 10 minutes of the inversion time parameter for optimal nulling of viable myocardium was calculated. Receiver operator characteristic (ROC) curve analysis was performed to compare the performance of late gadolinium-enhanced infarct imaging at increasing delays after contrast agent administration. RESULTS Significantly different T1 values were reached after 10 minutes between the LV bloodpool, infarcted, and viable myocardium. The T1 difference between myocardial infarcts and the LV bloodpool increased over time, while the difference between viable myocardium and the LV bloodpool decreased. ROC curve analysis showed a decrease in performance of a fixed T1 value to discriminate between the LV bloodpool and viable myocardium over time, while there was a marked increase in the discrimination between the LV bloodpool and infarcted myocardium. CONCLUSION The ability to discriminate between infarcted myocardium and the LV bloodpool improves with an increasing delay after contrast agent administration while discrimination between viable myocardium and the LV bloodpool decreases.
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Affiliation(s)
- James W Goldfarb
- Department of Research and Education, Saint Francis Hospital, Roslyn, New York 11576, USA.
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Abstract
Balanced steady-state free precession (Bal-SSFP) techniques produce excellent anatomic images of renal arteries without the use of contrast agents and are relatively flow-insensitive. Electrocardiography (ECG)-triggered and non-ECG-triggered sequences have been shown to be quite sensitive for detection of regional arterial stenosis (RAS), and the already high specificity is likely to increase with further refinement of the techniques. Bal-SSFP sequences can be used as a screening tool or as an alternative to contrast-enhanced (CE) magnetic resonance angiography (MRA) when contrast agents are contraindicated. In addition to morphologic imaging of RAS, non-CE techniques can be used in functional assessment of hemodynamic significance. The complimentary tools can be used alone or in combination with CE-MRA for MR imaging of renal vascular hypertension.
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Affiliation(s)
- Gregory J Wilson
- Department of Radiology (AA010-J), University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Philips Healthcare, Cleveland, OH, USA.
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Zhang JL, Rusinek H, Bokacheva L, Lim RP, Chen Q, Storey P, Prince K, Hecht EM, Kim DC, Lee VS. Angiotensin-converting enzyme inhibitor-enhanced MR renography: repeated measures of GFR and RPF in hypertensive patients. Am J Physiol Renal Physiol 2009; 296:F884-91. [PMID: 19158343 DOI: 10.1152/ajprenal.90648.2008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study aims to assess the feasibility of a protocol to diagnose renovascular disease using dual MR renography acquisitions: before and after administration of angiotensin-converting enzyme inhibitor (ACEi). Results of our simulation study aimed at testing the reproducibility of glomerular filtration rate (GFR) and renal plasma flow demonstrate that for a fixed overall dose of 12 ml gadolinium-based contrast material (500 mmol/l), the second dose should be approximately twice as large as the first dose. A three-compartment model for analyzing the second-injection data was shown to appropriately handle the tracer residue from the first injection. The optimized protocol was applied to 18 hypertensive patients without renovascular disease, showing minimal systematic difference in GFR measurements before and after ACEi of 0.8 +/- 4.4 ml/min or 2.7 +/- 14.9%. For 10 kidneys with significant renal artery stenosis, GFR decreased significantly after ACEi (P < 0.001, T value = 3.79), and the difference in GFR measurements before and after ACEi averaged 8.3 +/- 6.9 ml/min or 26.2 +/- 43.9%. Dual-injection MRI with optimized dose distribution appears promising for ACEi renography by offering measures of GFR changes with clinically acceptable precision and accuracy.
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Affiliation(s)
- Jeff L Zhang
- Dept. of Radiology, New York Univ. School of Medicine, 660 First Ave., 4th Floor, New York, NY 10016, USA.
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Park JK, Rhee TK, Cashen TA, Shin W, Schirf BE, Gehl JA, Larson AC, Prasad PV, Li D, Carroll TJ, Omary RA. Renal Artery Stenosis in Swine: Feasibility of MR Assessment of Renal Function during Percutaneous Transluminal Angioplasty. Radiology 2007; 244:144-50. [PMID: 17495175 DOI: 10.1148/radiol.2433060184] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively test--in a swine model of renal artery stenosis (RAS)--the hypothesis that magnetic resonance (MR) imaging can reveal changes in renal function at the time of percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS In this animal care and use committee-approved study, high-grade unilateral RAS was surgically induced in six pigs. MR imaging at 3.0 T was used for intraprocedural assessment of the anatomic and physiologic changes induced by x-ray-guided PTA. With use of MR imaging, changes in single-kidney glomerular filtration rate, extraction fraction, and renal blood flow were assessed during PTA. The arterial diameter of stenosis before and after PTA was assessed by using conventional digital subtraction angiography. Mean changes in functional and anatomic parameters were compared by using the Wilcoxon signed rank test (alpha = .05). RESULTS At digital subtraction angiography, the mean percentage of stenosis was 69% +/- 10 (standard deviation) before PTA and 26% +/- 10 after PTA (P<.03). Mean pre- and post-PTA extraction fraction values were 0.11 +/- 0.03 and 0.19 +/- 0.06, respectively (P<.03). The mean single-kidney glomerular filtration rate before PTA, 19 mL/min +/- 13, increased to 41 mL/min +/- 33 after PTA (P<.03). There was no significant change in mean renal blood flow after PTA (P=.44). CONCLUSION In swine, MR imaging can reveal changes in renal function after x-ray-guided PTA for unilateral RAS.
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Affiliation(s)
- Jonathan K Park
- Department of Radiology, Northwestern University Feinberg School of Medicine, 448 E Ontario St, Suite 700, Chicago, IL 60611, USA
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Abstract
Renal artery stenosis (RAS) is the leading cause of secondary hypertension. Magnetic resonance (MR) imaging and in particular MR angiography have evolved into important diagnostic tools for the detection and grading of RAS due to the lack of ionizing radiation and nephrotoxic contrast agent. This review describes state-of-the-art MR angiographic techniques and introduces the reader to current concepts of RAS grading with MR angiography. We compare MR angiography with conventional angiography and intravascular ultrasound as a standard of reference. The technical basis of functional imaging techniques such as arterial spin labeling perfusion measurements, contrast-enhanced perfusion measurements, and MR flow measurements are explained. Their value for the grading and detection of RAS and for the differentiation of renovascular from renal parenchymal disease is discussed. An overview about imaging during and after interventional therapy of RAS and an introduction to the current understanding of prediction of successful interventional therapy finishes this review.
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Affiliation(s)
- S O Schoenberg
- Institute of Clinical Radiology, University Hospitals Grosshadern, Ludwig-Maximilians-University Munich, Marchioninistrasse 15, 81377 Munich, Germany.
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Michoux N, Vallée JP, Pechère-Bertschi A, Montet X, Buehler L, Van Beers BE. Analysis of contrast-enhanced MR images to assess renal function. Magn Reson Mater Phy 2006; 19:167-79. [PMID: 16906431 DOI: 10.1007/s10334-006-0045-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Revised: 07/10/2006] [Accepted: 07/10/2006] [Indexed: 11/25/2022]
Abstract
The image analysis and kinetic modeling methods used in dynamic contrast-enhanced magnetic resonance imaging of the kidney are reviewed. Image analysis includes various techniques of coregistration and segmentation. Few methods have been completely implemented. Nevertheless, the use of coregistration may become a standard to decrease the effect of motion on abdominal images and improve the quality of the renal signals. Kinetic models are classified into three categories: enhancement-based, external and internal representations. Enhancement-based representations are limited to a basic analysis of the tracer concentration curves in the kidneys. Their relationship to the underlying physiology is complex and undefined. However, they can be used to evaluate the split renal function. External representations assess the kidney input and output. An external representation based on the up-slope of the renal enhancement to calculate the renal perfusion is commonly used because of its simplicity. In contrast, external representation based on deconvolution or identification methods remain underexploited. For glomerular filtration, an internal representation based on a two-compartmental model is mostly used. Internal representations based on multi-compartmental models describe the renal function in a more realistic way. Because of their numerical complexity, these models remain rarely used.
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Affiliation(s)
- N Michoux
- Diagnostic Radiology Unit, Université Catholique de Louvain, St-Luc University Hospital, Avenue Hippocrate 10, 1200. Brussels, Belgium.
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Abstract
Magnetic resonance imaging (MRI) provides exquisite anatomic detail of various organs and is capable of providing additional functional information. This combination allows for comprehensive diagnostic evaluation of pathologies such as ischemic renal disease. Noninvasive MRI techniques could facilitate translation of many studies performed in controlled animal models using technologies that are invasive to humans. Such a translation is being recognized as essential because many proposed interventions and drugs that prove efficacious in animal models fail to do so in humans. In this article, we review the state-of-the-art functional MRI technique as applied to the kidneys.
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Affiliation(s)
- Pottumarthi V Prasad
- Dept. of Radiology, Walgreen Jr. Bldg., Suite 507, Evanston Northwestern Healthcare, 2650 Ridge Ave., Evanston, IL 60201, USA.
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Michoux N, Montet X, Pechère A, Ivancevic MK, Martin PY, Keller A, Didier D, Terrier F, Vallée JP. Parametric and quantitative analysis of MR renographic curves for assessing the functional behaviour of the kidney. Eur J Radiol 2005; 54:124-35. [PMID: 15797302 DOI: 10.1016/j.ejrad.2004.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2004] [Revised: 04/08/2004] [Accepted: 04/13/2004] [Indexed: 11/24/2022]
Abstract
The aim of this study was to refine the description of the renal function based on MR images and through transit-time curve analysis on a normal population and on a population with renal failure, using the quantitative model of the up-slope. Thirty patients referred for a kidney MR exam were divided in a first population with well-functioning kidneys and in a second population with renal failure from ischaemic kidney disease. The perfusion sequence consisted of an intravenous injection of Gd-DTPA and of a fast GRE sequence T1-TFE with 90 degrees magnetisation preparation (Intera 1.5 T MR System, Philips Medical System). To convert the signal intensity into 1/T1, which is proportional to the contrast media concentration, a flow-corrected calibration procedure was used. Following segmentation of regions of interest in the cortex and medulla of the kidney and in the abdominal aorta, outflow curves were obtained and filtered to remove the high frequency fluctuations. The model of the up-slope method was then applied. Significant reduction of the cortical perfusion (Qc = 0.057+/-0.030 ml/(s 100 g) to Qc = 0.030 +/- 0.017 ml/(s 100 g), P < 0.013) of the medullary perfusion (Qm = 0.023 +/- 0.018 ml/(s 100 g) to Qm = 0.011 +/- 0.006 ml/(s 100 g), P < 0.046) and of the accumulation of contrast media in the medulla (Qa = 0.005 +/- 0.003 ml/(s 100 g) to Qa = 0.0009 +/- 0.0008 ml/(s 100 g), P < 0.001) were found in presence of renal failure. High correlations were found between the creatinine level and the accumulation Qa in the medulla (r2 = 0.72, P < 0.05), and between the perfusion ratio Qc/Qm and the accumulation Qa in the medulla (r2 = 0.81, P < 0.05). No significant difference was found in times to peak between both populations despite a trend showing Ta the time to the end of the increasing contrast accumulation period in the medulla, arriving later for renal failure. Advances in MR signal calibration with the building of quantitative model such as the up-slope allow to assess kinetic and haemodynamic and functional parameters of the diseased kidney.
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Affiliation(s)
- N Michoux
- Unité d'imagerie Numérique, Département de Radiologie, Hôpital Universitaire de Genève, Rue Micheli-du-Crest 24, CH-1211 Geneva 14, Switzerland.
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Affiliation(s)
- Henrik J Michaely
- Department of Clinical Radiology, University Hospitals, Ludwig Maximilians University-Munich, Grosshadern Marchioninistrasse 15, Munich 81377, Germany.
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Abstract
MR imaging is the only noninvasive test that may provide a complete picture of renal status with minimal risk to the patient, simultaneously improving diagnosis and lowering costs. This article reviews several MR renography techniques, including approaches for quantifying renal perfusion and glomerular filtration rate. Also discussed are clinical applications for the diagnosis and follow-up of renovascular disease, hydronephrosis,and renal transplant dysfunction. The article concludes with an overview of technical problems and challenges facing MR renography.
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Affiliation(s)
- Ambrose J Huang
- Department of Radiology-MR Imaging, New York University Medical Center, 530 First Avenue, HCC Basement, New York, NY 10016, USA
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Gandy SJ, Sudarshan TAP, Sheppard DG, Allan LC, McLeay TB, Houston JG. Dynamic MRI contrast enhancement of renal cortex: a functional assessment of renovascular disease in patients with renal artery stenosis. J Magn Reson Imaging 2004; 18:461-6. [PMID: 14508783 DOI: 10.1002/jmri.10381] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To evaluate differences in the magnitude and time course of renal cortical contrast uptake in patients with minimal, moderate, and severe renal artery stenosis (RAS) using contrast-enhanced magnetic resonance renography (CE-MRR). MATERIALS AND METHODS CE-MRR was performed on 56 patients with renovascular disease using a three-dimensional volume interpolated breath-hold examination (VIBE) perfusion sequence. After administration of 2 mL of contrast, nine sequential axial VIBE datasets were acquired: at baseline, 7, 14, 21, 45, 60, 120, 180, and 240 seconds. Aortic peak signal enhancement and cortical peak signal enhancement through the mid portion of each kidney was recorded, along with the time delay between each peak. Each renal artery was subsequently examined using three-dimensional contrast-enhanced MR angiography, and graded as being minimally (0%-30%), moderately (31%-70%), or severely (71%-100%) stenotic. RESULTS When the data were subdivided by RAS category, the cortical to aortic peak enhancement ratio (CAPR) reduced with increasing RAS. Further, the cortical to aortic time delay (CATD) increased with increasing RAS. These measurements were statistically significant between patients with minimal and moderate RAS compared to severe RAS CONCLUSION: CE-MRR can assist in the differentiation of patients with minimal or moderate RAS from those with severe RAS.
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Affiliation(s)
- Stephen J Gandy
- Tayside Institute for Cardiovascular Research, Department of Clinical Radiology, Ninewells Hospital, Dundee, UK.
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Abstract
MR imaging is the only single noninvasive test that can potentially provide a complete picture of renal status with minimal risk to the patient, simultaneously improving diagnosis while lowering medical costs by virtue of its being a single test. The strengths of MR imaging lie in its high spatial and temporal resolution and its lack of exposure to ionizing radiation and nephrotoxic contrast agents. This article reviews the use of MR imaging for quantification of renal functional parameters and its application to clinical problems, such as RVD, hydronephrosis, and renal transplantation. Although advances in both the technical and clinical aspects of functional renal MR imaging have been made, much remains to be done. The preliminary results reported in the many studies reviewed are exciting, but these techniques need to be validated against accepted standards where such standards exist. In addition, and perhaps more important, the effects of these new diagnostic methods on patient outcomes must be studied. Finally, further progress in image processing and analysis must be made to make functional renal MR imaging truly practical. With these advances, one can expect functional renal MR imaging to play an ever-expanding and influential role in the care and management of the patient with renal disease.
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Affiliation(s)
- Ambrose J Huang
- Department of Radiology-MRI, New York University Medical Center, 530 First Avenue, HCC Basement, New York, NY 10016, USA
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Teh HS, Ang ES, Wong WC, Tan SB, Tan AGS, Chng SM, Lin MBK, Goh JSK. MR renography using a dynamic gradient-echo sequence and low-dose gadopentetate dimeglumine as an alternative to radionuclide renography. AJR Am J Roentgenol 2003; 181:441-50. [PMID: 12876024 DOI: 10.2214/ajr.181.2.1810441] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Our aim was to evaluate the feasibility of acquiring an MR signal intensity-time renographic curve and dynamic serial images in a way similar to that of acquiring radionuclide renograms, with a dynamic gradient-echo sequence and a low-dose gadopentetate dimeglumine technique, using a commonly available 1.5-T MR scanner. SUBJECTS AND METHODS. Patients who underwent both radionuclide and MR renographic studies within a 3-month period were included in the analysis. This yielded 21 studies from 19 patients. Nineteen of the 21 studies were available for analysis. Two studies were excluded because of technical errors during MR renographic acquisition. Serial MR renograms were obtained using a dynamic two-dimensional spoiled gradient-echo fast low-angle shot T1-weighted sequence. Low-dose IV furosemide and gadopentetate dimeglumine (0.025 mmol/kg of body weight) were administered. Intensity-time curves were obtained from the manually selected regions of interest over the renal parenchyma and whole kidney for calculation of split renal function and assessment of urinary excretion, respectively. Results were compared with those obtained with radionuclide renography. RESULTS Good correlation (Pearson's correlation coefficient, r = 0.97, p < 0.001) was observed when the volume-corrected split renal function acquired with MR renography was compared with that obtained with radionuclide renography. There was also good agreement in the excretory curve patterns (weighted kappa(observer 1) = 0.77 and kappa(observer 2) = 0.81) between the two techniques. CONCLUSION Dynamic MR gradient-echo imaging with a low-dose gadopentetate dimeglumine technique can produce an intensity-time curve and serial dynamic images of the urinary system, in a way similar to that of radionuclide renography. This technique allows assessment of split renal function and urinary excretory status and is a feasible alternative to radionuclide renography.
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Affiliation(s)
- Hui Seong Teh
- Department of Radiology, Changi General Hospital, 2, Simei St. 3, S, 529889 Singapore
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Lee VS, Rusinek H, Noz ME, Lee P, Raghavan M, Kramer EL. Dynamic three-dimensional MR renography for the measurement of single kidney function: initial experience. Radiology 2003; 227:289-94. [PMID: 12615998 DOI: 10.1148/radiol.2271020383] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A three-dimensional magnetic resonance (MR) renographic method to measure single kidney glomerular filtration rate (GFR) and split renal function was developed that is based on renal signal intensity measurements during 2-3 minutes after intravenous injection of a low dose (2 mL or 0.01 mmol/kg) of gadopentetate dimeglumine. In nine subjects, single kidney MR GFR indices correlated well with technetium 99m (99mTc) diethylenetriaminepentaacetic acid (DTPA) clearance (r = 0.7-0.8) for GFR values of 7-48 mL/min. MR right kidney split renal function values (range, 32%-59%) also correlated well with 99mTc-DTPA radionuclide measurements (r = 0.76); differences between the two methods averaged 0.8% +/- 8. MR renography was performed along with contrast material-enhanced MR imaging of the kidneys and renal arteries and added 8 minutes or less to the total examination time.
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Affiliation(s)
- Vivian S Lee
- Department of Radiology-MRI, New York University Medical Center, 530 First Ave, HCC Basement, New York, NY 10016, USA.
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Schoenberg SO, Aumann S, Just A, Bock M, Knopp MV, Johansson LO, Ahlstrom H. Quantification of renal perfusion abnormalities using an intravascular contrast agent (part 2): results in animals and humans with renal artery stenosis. Magn Reson Med 2003; 49:288-98. [PMID: 12541249 DOI: 10.1002/mrm.10383] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The interrelation between the morphologic degree of renal artery stenosis and changes in parenchymal perfusion is assessed using an intravascular contrast agent. In seven adult foxhounds, different degrees of renal artery stenosis were created with an inflatable clamp implanted around the renal artery. Dynamic susceptibility-weighted gradient-echo imaging was used to measure signal-time curves in the renal artery and the renal parenchyma during administration of 1.5 mg/kg BW of an intravascular ultrasmall particle iron oxide (USPIO) contrast agent. From the dynamic series, regional renal blood volume (rRBV), regional renal blood flow (rRBF), and mean transit time (MTT) were calculated. The morphologic degree of stenosis was measured in the steady state using a high-resolution 3D contrast-enhanced (CE) MR angiography (MRA) sequence (voxel size = 0.7 x 0.7 x 1 mm(3)). Five patients with renoparenchymal damage due to long-standing renal artery stenosis were evaluated. In the animal stenosis model, cortical perfusion remained unchanged for degrees of renal artery stenosis up to 80%. With degrees of stenoses > 80%, cortical perfusion dropped to 151 +/- 54 ml/100 g of tissue per minute as compared to a baseline of 513 +/- 76 ml/100 g/min. In the patients, a substantial difference in the cortical perfusion of more than 200 +/- 40 ml/100 g/min between the normal and the ischemic kidneys was found. The results show that quantitative renal perfusion measurements in combination with 3D-CE-MRA allow the functional significance of a renal artery stenosis to be determined in a single MR exam. Differentiation between renovascular and renoparenchymal disease thus becomes feasible.
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Affiliation(s)
- Stefan O Schoenberg
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
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Schoenberg SO, Knopp MV, Londy F, Krishnan S, Zuna I, Lang N, Essig M, Hawighorst H, Maki JH, Stafford-Johnson D, Kallinowski F, Chenevert TL, Prince MR. Morphologic and functional magnetic resonance imaging of renal artery stenosis: a multireader tricenter study. J Am Soc Nephrol 2002; 13:158-169. [PMID: 11752033 DOI: 10.1681/asn.v131158] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The effect of combined morphologic and functional magnetic resonance (MR) imaging on the interobserver and intermodality variability for the grading of renal artery stenosis is assessed. In a randomized, blinded tricenter analysis, seven readers evaluated 43 renal arteries on x-ray digital subtraction angiography (DSA), 3D-Gadolinium MR angiography (3D-Gd-MRA), cine phase-contrast flow measurement (PC-flow), and a combined analysis of the last two. Interobserver variability was assessed for the grading of renal artery stenosis as well as regional vessel visibility. Intermodality variability for stenosis grading was analyzed in cases in which the readers agreed on the degree of stenosis in DSA. DSA had a substantial interobserver variability for the grading of stenosis (mean kappa kappa 0.64). 3D-Gd-MRA revealed a slightly improved interobserver variability but incorrectly graded 6 of 34 stenoses on a two-point scale (<50%, > or =50%). The combined approach of 3D-Gd-MRA and PC-flow revealed the best (P = 0.0003) interobserver variability (median kappa = 0.75) and almost perfect intermodality agreement with DSA (97% of cases). These findings were confirmed in a prospective analysis of 97 renal arteries. The vessel visibility of the renal artery ostium was significantly better in 3D-Gd-MRA than in DSA, whereas the visibility of the hilar and intrarenal vessels was significantly worse (P = 0.0001). A combined morphologic and functional MR examination significantly reduces interobserver variability and offers reliable and reproducible grading of renal artery stenosis based on stenosis morphology and hemodynamic changes. It can be considered a safe and noninvasive alternative for diagnostic DSA in cases that do not require assessment of intrarenal vessels.
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Affiliation(s)
- Stefan O Schoenberg
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Michael V Knopp
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Frank Londy
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Sumati Krishnan
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Ivan Zuna
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Nicole Lang
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Marco Essig
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Hans Hawighorst
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Jeffrey H Maki
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - David Stafford-Johnson
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Friedrich Kallinowski
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Thomas L Chenevert
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
| | - Martin R Prince
- *Department of Radiology, University of Michigan, Ann Arbor, Michigan; Department of Radiology, German Cancer Research Center (dkfz), and Department of Surgery, University Hospitals, Heidelberg, Germany; and Department of Radiology, Veteran Affairs Medical Center, Ann Arbor, Michigan
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Omary RA, Henseler KP, Unal O, Maciolek LJ, Finn JP, Li D, Nemcek AA, Vogelzang RL, Grist TM. Comparison of intraarterial and IV gadolinium-enhanced MR angiography with digital subtraction angiography for the detection of renal artery stenosis in pigs. AJR Am J Roentgenol 2002; 178:119-23. [PMID: 11756103 DOI: 10.2214/ajr.178.1.1780119] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Catheter-based intraarterial injections of gadolinium are useful during MR imaging-guided endovascular procedures to generate rapid vascular road maps. Using an animal model of renal artery stenosis, we tested the hypothesis that intraarterial gadolinium-enhanced MR angiography is as accurate as IV gadolinium-enhanced MR angiography and digital subtraction angiography (DSA). We also tested the hypothesis that intraarterial MR angiography uses less gadolinium than IV MR angiography. MATERIALS AND METHODS We induced bilateral renal artery stenosis in five pigs. All pigs underwent comparative imaging with DSA, IV MR angiography, and aortic catheter-directed intraarterial MR angiography. For IV and intraarterial MR angiography, we used the same three-dimensional acquisition. We assessed differences in quantitative stenosis measurements among DSA, IV MR angiography, and intraarterial MR angiography using the Wilcoxon's signed rank test. RESULTS Mean stenosis measurements (+/-SD) were as follows: DSA, 58% +/- 12%; IV MR angiography, 63% +/- 9.3%; and intraarterial MR angiography, 64% +/- 11%. There were no statistically significant differences in accuracy between DSA and IV MR angiography (p = 0.06), DSA and intraarterial MR angiography (p = 0.16), or IV and intraarterial MR angiography (p = 0.70). Intraarterial MR angiography used a mean gadolinium dose of 5.6 mL, compared with 9 mL for IV MR angiography. CONCLUSION In swine, IV and intraarterial MR angiography have a similar accuracy for detecting renal artery stenosis. Intraarterial MR angiography uses smaller doses of injected gadolinium.
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Affiliation(s)
- Reed A Omary
- Department of Radiology, Northwestern University Medical School, 676 N. St. Claire St., Ste. 800, Chicago, IL 60611, USA
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Abstract
PURPOSE To develop a low-dose magnetic resonance (MR) renographic method performed with and without an angiotensin converting enzyme (ACE) inhibitor and in conjunction with gadolinium-enhanced MR angiography in patients with suspected renovascular disease. MATERIALS AND METHODS Thirty-two patients underwent MR renography (turbo fast low-angle shot sequence: repetition time, 5 msec; echo time, 2.3 msec; flip angle, 15 degrees; one coronal image acquired every 2 seconds for 4 minutes) following intravenous injection of 2 mL of gadopentetate dimeglumine, which was repeated following intravenous injection of an ACE inhibitor. Contrast material-enhanced MR angiography was also performed. On the basis of renographic findings, renal cortex and renal medulla enhancement curves and normalized enhancement ratios were analyzed. RESULTS The cortex and medulla showed an early transient period of enhancement within 20 seconds (vascular phase). During 1-2 minutes, a second, gradual increase in medullary enhancement, reflecting transit of filtered contrast material, was observed that was significantly greater in patients with a serum creatinine level less than 2 mg/dL (177 micromol/L) than in those with a level of 2 mg/dL or greater (P < .01). After injection of the ACE inhibitor, patients with elevated creatinine levels showed low renal medullary enhancement regardless of the presence of renal artery stenosis (RAS). However, in patients with creatinine less than 2 mg/dL, medullary enhancement ratios after injection of the ACE inhibitor were consistently lower in patients with RAS of 50% or greater than in those without stenosis (P = .02 to .08). CONCLUSION Low-dose MR renography can be performed in the clinical setting before and after injection of an ACE inhibitor, and its potential use for evaluating decreased renal function as a consequence of RAS is promising.
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Affiliation(s)
- V S Lee
- Department of Radiology-MRI, New York University, 530 First Ave, HCC Basement, New York, NY 10016, USA.
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