Absolute renal blood flow quantification by dynamic MRI and Gd-DTPA

Vallée, Jean‐Paul; Lazeyras, François; Khan, Haleem; Terrier, François

doi:10.1007/s003300000434

Cited by 96 publications

(70 citation statements)

References 25 publications

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“…Fast acquisition techniques allow suffi cient temporal resolution to monitor intra-renal signal changes during fi rst pass of the agent. Approaches have been described [43] enabling quantifi cation of absolute cortical and medullary perfusion. Th is would make gadoliniumbased MRI technology of great interest for the assessment of renal perfusion.…”

Section: Contrast-enhanced Mri Mod Alitiesmentioning

confidence: 99%

Measurement of Kidney Perfusion in Critically Ill Patients

Schneider

Goodwin

Bellomo

2013

Annual Update in Intensive Care and Emergency Medicine 2013

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Acute kidney injury (AKI) is a major complication of critical illness [1] occurring in 30 to 40 % of all critically ill patients and in its sev ere form requires renal replacement therapy (RRT), in approximately 5 % of patients [2]. AKI has been s hown to be an independent predictor for mortality [3] and is associated with invasive therapy and substantial costs [4].Despite its impor tance, the pathoph ysiology of AKI is still poorly understood. AKI is most commonly associated with systemic diseases, such as septic shock, major surgery and cardiogenic shock [1], but a specifi c mechanism causing AKI to develop in specifi c patients can rarely be determined. Since the early description of an "acute uremia syndrome" in crush injury victims during World War II [5,6] and its association with histopathological fi ndings similar to those found in experimental renal artery ligation, ischemia or some form of alteration in renal blood fl ow has been thought to play a pivotal role in the pathogenesis of AKI. Th is paradigm that essentially all AKI in critically ill patients is the result of some form or degree of ischemia remains of continuing conceptual dominanc e to this day [7]. Despite such dominance, there are only very limited data supporting this concept. In a recent systematic review, Prowle et al. [8] highlighted the extraordinary fact that renal blood fl ow measurement, irrespective of the technique used, has only been reported in 46 critically ill patients (fi ve studies) within the last sixty years. Th us, our knowledge, understanding, and theoretical constructs regarding global renal perfu sion in critically ill patients with RRT-treated AKI (an estimated 5 % of all ICU admissions for a total of approximately a quarter of a million such patients each year in developed countries alone) is, like an inverted pyramid, based on extremely weak evidence.Furthermore, given the complex and heterogeneous nature of the renal vasculature, evaluating the fl ow in the main renal arteries (macrocirculation) might not provide suffi cient information to adequately understand perfusion alterations in complex diseases, such as septic or cardio genic shock. Indeed, some pathophysiological processes may be associated with increased global renal blood fl ow [9,10] despite loss of f un ction. In such instances, there is experimental evidence that, at least in sepsis, this phenomenon may be caused by intra-renal shunting [11]. Hence, correlation between macroscopic renal blood fl ow and function is far from linear. Th erefore, techniques allowing the study of microcircu latory parameters, such as cortico-med ullary perfusion ratio and regional tissue oxygenation measurement, and assessment of their relative change over time may be more valuable in increasing our understanding of the pathophysiology of AKI.In this state-of-the art review, we discuss the value, challenges, limitations, safety and feasibility of diff erent techniques for the measurement of kidney perfusion in critically ill patients. Th e advantages of each technique wi...

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Section: Contrast-enhanced Mri Mod Alitiesmentioning

confidence: 99%

Measurement of Kidney Perfusion in Critically Ill Patients

Schneider

Goodwin

Bellomo

2013

Annual Update in Intensive Care and Emergency Medicine 2013

View full text Add to dashboard Cite

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“…7) (62,(64)(65)(66)(67)(68)(69)(70)(71)(72). To data there are only a few clinical studies measuring renal perfusion.…”

Section: Functional Mr Imaging Of the Kidneysmentioning

confidence: 99%

“…Fundamental work was published by Dujardin et al who demonstrated age-related changes in renal perfusion in men, but only little change in women (73). Clinical applications have so far mainly focused on patients with renal artery stenosis in whom two studies found significantly decreased renal perfusion parameters associated with significant renal artery stenosis (64,65). They reported a mean blood flow of 2.54 mL/ min/g tissue for healthy patients, with this value dropping to 1.09 mL/min/g tissue for patients with high-grade renal artery stenosis.…”

Section: Functional Mr Imaging Of the Kidneysmentioning

confidence: 99%

Renovascular imaging in the NSF Era

Roditi

Maki

Oliveira

et al. 2009

Magnetic Resonance Imaging

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The detection of the association between nephrogenic systemic fibrosis (NSF), a rare but potentially life‐threatening disease only encountered in patients with severely impaired renal function, and the previous administration of some Gd‐chelates has cast a shadow on the administration of Gd‐chelates in patients with chronic renal failure. So far, contrast‐enhanced MR‐angiography (MRA) was considered the best diagnostic modality in patients with suspected renal disease. This review explores the most appropriate use of renal MRA with a focus on newly developed nonenhanced MRA techniques. Nonenhanced MRA techniques mainly based on SSFP with ECG‐gating allow for acceptable spatial resolution to visualize at least the proximal parts of the renal arteries. In addition functional renal imaging techniques and their current clinical role are critically appreciated. J. Magn. Reson. Imaging 2009;30:1323–1334. © 2009 Wiley‐Liss, Inc.

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“…[1], T 1 may also be calculated using Eq. [3], which does not require knowledge of the exact flip angle. To ensure that B 1 inhomogeneities do not degrade the accuracy of the thus obtained T 1 values, it was shown by Deichmann and Haase (10) that a low flip angle of less than 10°has to be used for the SFL sequence.…”

Section: T 1 Calculationmentioning

confidence: 99%

“…CA concentrations are commonly deduced from relative signal changes in dynamically acquired MR images. However, CA concentration-time curves obtained this way are prone to errors due to nonlinear signal behavior or tissue-specific influences (2), if no signal calibration is performed (3).…”

mentioning

confidence: 99%

Dynamic T₁ mapping predicts outcome of chemoradiation therapy in primary rectal carcinoma: Sequence implementation and data analysis

Kremser

Trieb

Rudisch

et al. 2007

Magnetic Resonance Imaging

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Purpose:To describe details about the implementation of a dynamic T 1 -mapping technique and a simple data analysis strategy that can be used to predict therapy outcome in primary rectal carcinoma and to investigate the physiologic meaning of the obtained parameter. Materials and Methods:Contrast-enhanced dynamic T 1 mapping was achieved with a snapshot fast low-angle shot (FLASH) T 1 mapping sequence implemented on a 1.5T MR scanner. This method was applied to 58 patients with primary rectal cancer before onset of chemoradiation therapy. A simple data analysis strategy based on the calculation of the maximum slope of the tissue concentration-time curve divided by the maximum of the arterial input function (AIF) was used as a measure of tumor microcirculation (PI values). Results:The snapshot FLASH (SFL) T 1 -mapping technique is accurate and sensitive enough to detect inhomogeneous uptake kinetics within tumor tissue. Classifying the patients into two groups according to therapy response showed lower mean PI values for responders as compared to nonresponders. PI was found to combine information about permeability surface area product (PS) and blood volume. Conclusions:The described method based on dynamic T 1 mapping has the potential to be a clinical tool for predicting therapy outcome of preoperative chemoradiation in patients with primary rectal carcinoma.

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Absolute renal blood flow quantification by dynamic MRI and Gd-DTPA

Cited by 96 publications

References 25 publications

Measurement of Kidney Perfusion in Critically Ill Patients

Measurement of Kidney Perfusion in Critically Ill Patients

Renovascular imaging in the NSF Era

Dynamic T₁ mapping predicts outcome of chemoradiation therapy in primary rectal carcinoma: Sequence implementation and data analysis

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Absolute renal blood flow quantification by dynamic MRI and Gd-DTPA

Cited by 96 publications

References 25 publications

Measurement of Kidney Perfusion in Critically Ill Patients

Measurement of Kidney Perfusion in Critically Ill Patients

Renovascular imaging in the NSF Era

Dynamic T1 mapping predicts outcome of chemoradiation therapy in primary rectal carcinoma: Sequence implementation and data analysis

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Product

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Dynamic T₁ mapping predicts outcome of chemoradiation therapy in primary rectal carcinoma: Sequence implementation and data analysis