Measurement of renal transit of gadopentetate dimeglumine with echo‐planar MR imaging

Wolf, Gerald; Hoop, B.; Cannillo, John; Rogowska, Jadwiga; Halpern, Elkan F.

doi:10.1002/jmri.1880040323

Cited by 33 publications

(30 citation statements)

References 26 publications

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“…The vascular medullary peak in the IRF is followed by a second peak with maximum around 80 s (Fig. 5), consistent with tubular passage and medullar concentration in the descending loop of Henle (21). Note that parallel to this peak there is a more rapid decrease in cortical IRFs.…”

Section: Extraction Fraction and Roi Curvessupporting

confidence: 68%

“…Functional comparison of the fine-structure is complicated by the fact that only few data are available quantifying the transit times through the different compartments of the nephron in humans. There is evidence that the passage through the proximal tubulus contortus has a duration of 10 s and sets in 30 s after arrival in the glomeruli (21). This may suggest that the second peak of cortical voxels (C2) reflects the passage through this compartment.…”

Section: Fine Structure Of the Irfmentioning

confidence: 99%

See 1 more Smart Citation

Quantification of renal perfusion and function on a voxel‐by‐voxel basis: A feasibility study

Dujardin

Sourbron

Luypaert

et al. 2005

Magnetic Resonance in Med

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The feasibility of a voxel-by-voxel deconvolution analysis of T 1 -weighted DCE data in the human kidney and its potential for obtaining quantification of perfusion and filtration was investigated. Measurements were performed on 14 normal humans and 1 transplant at 1.5 T using a Turboflash sequence. Signal time-courses were converted to tracer concentrations and deconvolved with an aorta AIF. Parametric maps of relative renal blood flow (rRBF), relative renal volume of distribution (rRVD), relative mean transit time (rMTT), and whole cortex extraction fraction (E) were obtained from the impulse response functions. For the normals average cortical rRBF, rRVD, rMTT, and E were 1.6 mL/min/mL (SD 0.8), 0.4 mL/mL (SD 0.1), 17s (SD 7), and 22.6% (SD 6.1), respectively. A gradual voxelwise rRBF increase is found from the center of two infarction zones toward the edges. Voxel IRFs showed more detail on the nefron substructure than ROI IRFs. In conclusion, quantitative voxelwise perfusion mapping based on deconvolved T 1 -DCE renal data is feasible, but absolute quantification requires inflow correction. rRBF maps and quantitative values are sufficiently sensitive to detect perfusion abnormality in pathologic areas, but further research is necessary to separate perfusion from extraction and to characterize the different compartments of the nephron on the ( Key words: renal; T-weighted; perfusion; deconvolution; quantificationDynamic contrast enhanced MRI is a promising noninvasive method for imaging renal perfusion and function (1-5), since it avoids the use of ionizing radiation and combines high temporal and spatial resolution. Moreover, Gd-DTPA is very well tolerated, not nephrotoxic, and has properties comparable to the radioisotopic 99mTc-DTPA (6,7). Tissue perfusion imaging with dynamic Gd-DTPA enhanced MRI therefore offers the potential for obtaining important information about organ viability, anatomy, and function in the normal as well as in the compromised kidney.Experiments with a rabbit model (1) have shown that Gd-DTPA enhanced bolus tracking and a deconvolution analysis of ROI signals permit quantitative measures of perfusion and filtration, independent of the effect of the shape and size of the bolus. On the other hand, results obtained with an intravascular contrast agent have shown that a pixel-by-pixel approach to perfusion quantification can be a useful tool for distinguishing normality from renal artery stenosis in dogs as well as humans (2,3).In this study we investigate the combination of both approaches: a pixel-by-pixel deconvolution analysis in the human kidney, using Gd-DTPA enhanced bolus tracking. We investigate the quality of the resulting parametric maps, evaluate to what extent they represent perfusion and extraction, and assess the potential of the technique for obtaining reliable quantification of renal blood flow and a measure of filtration. We also investigate the possibility of obtaining other parameters like the tracers' volume of distribution and mean transit time. Our first results...

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Section: Extraction Fraction and Roi Curvessupporting

confidence: 68%

Section: Fine Structure Of the Irfmentioning

confidence: 99%

Quantification of renal perfusion and function on a voxel‐by‐voxel basis: A feasibility study

Dujardin

Sourbron

Luypaert

et al. 2005

Magnetic Resonance in Med

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“…6. In this study, a two compartments model with Patlak-Rutland technique [22] was applied to evaluate the effectiveness of the vascular compartment segmentation. The formula is showed as follow.…”

Section: Resultsmentioning

confidence: 99%

“…It can be filtered free in kidneys like Inulin. Most researches [21][22][23][24] agree that signal change and Gd-DTPA concentration have a linear relationship. Especially low dose of contrast media can ensure that the signal loss associated with concentrated gadolinium chelates can be avoided and make MR renography compatible with routine clinical contrast-enhanced imaging of the kidneys and renal arteries [9,25].…”

Section: Signal Conversionmentioning

confidence: 97%

A renal vascular compartment segmentation method based on dynamic contrast-enhanced images

Bao

et al. 2016

THC

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Abstract. BACKGROUND: Kidney function assessment from renography has great potential for clinical diagnosis. Compartment models are the main analytical models in this field and the vascular compartment is the most important one, whether in the twocompartment model or three-compartment model. Currently, there are some published research studies on renal cortex segmentation. However, there are few publications introducing the methods on how to segment the vascular compartment yet. OBJECTIVE: The objective of this paper is to segment the vascular compartment automatically.METHODS: This method was tested on multi-phase scan images. A feature image reconstructed from the original images was used to segment the vascular compartment. It used the features of the time-density curve of each voxel in the contrast-enhanced images to distinguish vascular space from other areas. RESULTS: The segmentation result was evaluated by the renal glomerular filtration rate (GFR) analysis of a two-compartment model with the Patlak-Rutland technique. The dataset contained 11 kidney subjects whose GFR ranged from 19.8 ml/min to 74.9 ml/min. The results showed that the correlation between reference GFR and model derived GFR was 0.919 (P < 0.001). CONCLUSION: Compared with segmentation performed on certain phase images, this method can avoid the problem of subjective phase selection. For a given kidney data, the proposed method can always obtain the same segmentation result automatically.

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“…[27][28][29] Recording dynamic changes in signal intensity or disappearance rate after administration of gadopentetate dimeglumine has also been used to assess renal function, 30,31 …”

Section: Magnetic Resonance Imagingmentioning

confidence: 99%

Functional Assessment of the Circulation of the Single Kidney

Lerman

Rodriguez-Porcel²

2001

Hypertension

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Abstract-Functional alterations in the renal circulation that can contribute to abnormal renal perfusion have been demonstrated in various models of renal injury. To detect impairments in renal vascular function, renal flow reserve can be determined by repeated measurements of renal blood flow (RBF) during pharmacological challenge with short-acting vasodilators that should increase RBF in kidneys that are not severely damaged structurally. Among the invasive techniques for such measurements, the most readily available is probably the intravascular Doppler, which can be employed during renal angiography for rapid evaluation of changes in RBF during intrarenal injections of vasoactive substances. High-resolution tomographic imaging techniques, like electron-beam x-ray computed tomography, further offer the potential for noninvasive measurements of renal parenchymal perfusion and function, in association with either intrarenal or systemic injections of vasoactive substances. Acetylcholine is a potent short-acting renal vasodilator that can be useful to assess the response of the renal microcirculation, define renal flow reserve, and examine the endothelium-dependent responses of RBF. Such assessments of the function of the renal circulation can assist in evaluation of patients with systemic or renal disease for early detection and monitoring of renovascular injury. Key Words: renal circulation Ⅲ renal blood flow Ⅲ computed tomography Ⅲ acetylcholine U nder normal conditions, basal renal vascular tone is well regulated by many vasoactive systems that keep renal blood flow (RBF) in equilibrium, 1 including the endothelium-derived relaxing factor NO, prostaglandins, and the reninangiotensin system. 2 Therefore, at an early stage of renal disease, RBF may be normal, and impaired renal vascular tone may become evident only as an attenuated response during stimulus with vasoactive substances or physiological challenges. The mechanisms of the attenuated response have been postulated to include decreased release of vasodilators (eg, NO, prostaglandins) and co-existing vasoconstrictors (eg, thromboxane, angiotensin II), which may be released or rendered unopposed during challenge. The altered functional response may precede structural renal damage and can serve as a marker for abnormal handling of daily challenges by the kidney. Such impairment has been demonstrated in various models of renal injury, like hypertension, hypercholesterolemia, renal artery stenosis, ischemia and reperfusion, acute renal failure, diabetes mellitus, and aging. Hence, utilization of vasodilators to examine renal flow reserve (RFR) can serve to disclose subtle functional vascular alterations 3 and may allow early detection and monitoring of renovascular injury. For example, residual responsiveness of the intrarenal circulation to challenge may also reflect renal viability and may conceivably predict success of subsequent therapy (eg, revascularization).Evaluation of the reactivity of the single-kidney circulation entails rapid and successive meas...

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Measurement of renal transit of gadopentetate dimeglumine with echo‐planar MR imaging

Cited by 33 publications

References 26 publications

Quantification of renal perfusion and function on a voxel‐by‐voxel basis: A feasibility study

Quantification of renal perfusion and function on a voxel‐by‐voxel basis: A feasibility study

A renal vascular compartment segmentation method based on dynamic contrast-enhanced images

Functional Assessment of the Circulation of the Single Kidney

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