Quantitative scintigraphic parameters for the assessment of renal transplant patients
Introduction
In the last two decades various quantitative parameters from dynamic renal scintigraphy have been derived to facilitate the detection and follow-up of renal graft pathology [1]. The radionuclide renogram offers possibilities for the quantitative evaluation of the graft function. This is usually based on the analysis of the three phases of the renogram originally described by Taplin et al. [2]. The first phase of this division corresponds to the transit of the tracer bolus through the renal blood vessels. In the second phase the nephrons extract the radiotracer from the blood to be excreted into urine by either glomerular filtration and/or tubular excretion. The third phase corresponds to the drainage of the pelvicalcyeal system (Fig. 1). In order to evaluate the handling of the tracer by the kidney in a quantitative way various indices have been proposed [3]. The quantitative parameters that have been used to assess graft function in the post-operative period will be discussed comprehensively in this review, and have been listed in Table 1.
Section snippets
Assessment of renal graft perfusion
Damage to the microcirculation of the renal graft is an early event in the course of allograft dysfunction, usually preceding measurable functional derangements in the transplanted kidney [4]. Because recovery of the graft function is largely dependent on perfusion, the assessment of perfusion in the early post-transplant period is of utmost importance. Renal perfusion imaging (RPI) is defined as the rapid dynamic renal examination carried out in the 1st min after administration of
Assessment of parenchymal extraction and excretion
Radiopharmaceuticals with a well-defined mode of pharmacological handling such as [99mTc]DTPA, [131I]hippuran and [99mTc]MAG3 are excellent agents for the evaluation of graft function. Quantitative evaluation of the graft parenchymal function were first described as parameters applied to the [131I]OIH renograms. They include time to peak of the renogram (Tmax), half time of the elimination phase (T1/2), ratio of bladder and kidney curve heights, bladder appearance time, and kidney to background
Conclusion
Radionuclide scintigraphy of the renal transplants has assumed an important role, especially if carried out serially, in monitoring graft function in the post-transplant period. Both qualitative and quantitative information on the graft condition can be obtained from radionuclide renography. The literature is however replete with mathematical strategies for quantitating perfusion and parenchymal functions but none of these have enough diagnostic power for specific diagnosis of graft dysfunction.
Acknowledgements
The authors would like to thank Tilly Hagendoorn for her expert secretarial assistance in the preparation of this manuscript.
References (74)
Radionuclide diagnosis of allograft rejection
Semin Nucl Med
(1982)- et al.
Renal transplant evaluation
Semin Nucl Med
(1982) - et al.
Individual renal plasma flow determination in 2 min
J Urol
(1976) - et al.
Radionuclide evaluation of renal transplants
Semin Nucl Med
(1995) - et al.
Prospective evaluation of renal allograft dysfunction with Technetium-99m-diethylenetriaminepentaacetic acid renal scans
J Urol
(1984) - et al.
Serial hemodynamics after renal allotransplantation in man
Circulation
(1970) - et al.
The quantitative radiorenogram for total and differential renal blood flow measurements
J Nucl Med
(1963) Radioisotopic evaluation of renal transplants
Urol Radiol
(1992)- et al.
The renal transplant perfusion index: reduction in the error and variability
Eur J Nucl Med
(1994) Dynamic and static renal imaging
Correlation of gamma camera and flow meter determined renal blood flow measurements (Abstract)
J Nucl Med
Comprehensive evaluation of renal function in the transplanted kidney
J Nucl Med
Dynamic renal transplant imaging with Tc-99m DTPA (Sn) supplemented by a transplant perfusion index in the management of renal transplants
J Nucl Med
Radionuclide evaluation of renal transplants
J Nucl Med
Clinical application of the kidney to aortic blood flow index (K/A ratio)
Contrib Nephrol
Improvement in quantitative data analyses by numerical deconvolution techniques
J Nucl Med
Noninvasive measurement of blood flow and extraction fraction
Nucl Med Commun
Renal function studies using 99mTc-MAG3: pharmacokinetics and slope clearance determination
Contrib Nephrol
Renal arteriovenous transit times of technetium-radiolabeled chelates
J Nucl Med
The differential ratio. A method for describing blood flow in renal transplants
Nucl Med Commun
Normal range of [99mTc]MAG-3 renogram parameters in renal transplant recipients
Transplant Proc
Quantitation of renal function with technetium-99m MAG3
J Nucl Med
Measurement of changes of blood flow in renal transplants
Eur J Nucl Med
Tc-99m DTPA scans in renal allograft rejection and cyclosporine nephrotoxicity
Transplantation
Cortex perfusion index: a sensitive detector of acute rejection crisis in transplanted kidneys
J Nucl Med
Assessment of renal allograft pathology by scintigraphic and ultrasound index-markers
Clin Nucl Med
Cellular versus vascular rejection in transplant kidneys. Correlation of radionuclide and Doppler studies with histology
Nucl Med Commun
Transplant renography: 99m-Tc-DTPA versus 99m-Tc-MAG3. A preliminary note
Eur J Nucl Med
Tc-99m MAG3: A sensitive indicator for evaluating perfusion and rejection of renal transplants
Nucl Med Commun
The renogram and its quantitation
Br J Urol
Measurement and interpretation of renal transit times
Mean transit times without deconvolution
Nucl Med Commun
Renal perfusion and mean vascular transit time
Eur J Nucl Med
Deconvolution analysis of renal blood flow: evaluation of postrenal transplant complications
J Nucl Med
Non-invasive measurement of renal blood flow with 99mTc DTPA: comparison with radiolabelled microspheres
Cardiovasc Res
Quantification of renal haemodynamics with radionuclides
Eur J Nucl Med
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2022, Transplantation ProceedingsCitation Excerpt :They were chosen based on their simplicity (not requiring additional software or serum/urine collection), applicability, and ease of reproducibility. Perfusion parameters that quantitate blood flow to the graft were not included in this study, as they could be liable to technical errors (eg, fractionated bolus, extravasation) and would require higher doses of radiotracer to achieve adequate counting statistics [15,16]. Current literature on renal scintigraphy in the post-transplant setting varies significantly, particularly with regards to the choice of scan parameters, parameter cutoffs, and study endpoints.
Imaging in Renal Transplants: An Update
2021, Seminars in Nuclear MedicineCitation Excerpt :The perfusion curve of renal transplant has first pass peak followed by a second peak showing early tubular extraction (Fig. 3). It was shown that this second peak was flattened in graft rejection.37,38 Recent publication favors Tc-99m DTPA over Tc-99m MAG3 in renal transplant patients due to various perfusion parameters that detect change of function.25
SNMMI Procedure Standard/EANM Practice Guideline for Diuretic Renal Scintigraphy in Adults With Suspected Upper Urinary Tract Obstruction 1.0
2018, Seminars in Nuclear MedicineCitation Excerpt :Renal scans are sometimes performed after intravenous injection of approximately 370 MBq (10 mCi) of 99mTc-MAG3 or 99mTc-DTPA. Administration of activities in the range of 370 MBq may be required to obtain sufficient counts to visualize the initial bolus as it transits the aorta and kidneys (radionuclide angiogram) or to calculate quantitative flow indices.45-47 However, except for the evaluation of renal transplants, neither 2-second flow images nor quantitative flow calculations obtained in the first few seconds after injection have been shown to contribute to the evaluation of relative function, suspected obstruction, or renovascular hypertension.45-48
Renal scintigraphy for post-transplant monitoring after kidney transplantation
2018, Transplantation ReviewsCitation Excerpt :A quantitative analysis is preferable since it is less affected by inter-observer variability compared to a visual analysis with/without the use of a curve grading scale [14]. Over the years, several methods have been introduced with varying degrees of success, due to lack of diagnostic power and the inability to distinguish AR from ATN [12, 15]. In general, most quantitative indices describe the extraction/uptake and excretion/clearance.
Kidney
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