Administered activity optimization in 99mTc-MAG3 renography for adults (original) (raw)
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Annals of Nuclear Medicine, 2004
Background: Differential renal function (DRF) measurements are routinely corrected for background, which mainly affects the reproducibility and accuracy of the measurement. The present study was conducted to identify the most appropriate background ROI and optimal time interval in the calculation of DRF for EC renography. Materials and Methods: Nineteen patients were studied. For determination of DRF in EC renography, the selected time intervals were 0.5-1.5; 0.5-2; 1-2; 1.5-2.5; 2-3 min, and the background ROI types were inferolateral crescent, lateral crescent, and perirenal shaped. The reference DRF was obtained through DMSA study. For low functioning kidney of each patient, relative uptake differences between the DMSA and EC scans were calculated. Then, the mean differences and the standard deviations were found. Results: The highest correlation was between the DRF values obtained using inferolateral background ROI in 0.5-2 minutes of EC scintigraphy and the DRF values obtained through posterior DMSA images (r = 0.9889). However, there were no statistically significant differences between the mean DRF values obtained for each time interval with each ROI type (p > 0.05). For all the time intervals and background ROIs, the mean of the differences was <0.9%. In conclusion, in obtaining comparable DRF values from EC and DMSA studies, none of the background types proved superior. Also our research for optimal time interval showed that EC scintigraphy underestimates the DRF when compared to DRF obtained from DMSA study. The DRF has a tendency to decrease as the later time intervals are used. The time intervals less than 2.5 minutes show lower underestimation of DRF values.
European Journal of Radiology, 2010
Purpose: The aim of this study was to investigate (a) the effect the choice of the region of interest (ROI) defining the aortic input function (AIF) has on the estimation of renal perfusion and filtration in dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) renography, and (b) the reproducibility of these parameters. Using renal DCE-MRI and a three-compartment model analysis, this work evaluated the effect two different AIFs, derived from variable sized ROIs in the aorta, has on calculating DCE-MRI renal perfusion and filtration values in a group of healthy adult volunteers who underwent two consecutive renal DCE-MRI studies. Methods: Fifteen healthy volunteers underwent two DCE-MRI studies under similar physiological conditions. Oblique-coronal DCE-MRI data volumes were acquired on a 1.5 T Siemens Avanto scanner with a 3D-FLASH pulse-sequence (TE/TR = 0.53/1.63 ms, flip angle = 17 • , acquisition matrix = 128 × 104 voxels, strong fat saturation, PAT factor = 2 (GRAPPA) and 400 mm × 325 mm FOV). Each dynamic dataset consisted of 18 slices of 7.5 mm thickness (no gap) and an in-plane resolution of 3.1 mm × 3.1 mm, acquired every 2.5 s for not less than 5 minutes. During the MR scan a dose of 0.05 mmol (0.1 mL) kg −1 body weight of dimeglumine gadopentetate (Magnevist) was injected intravenously (2 mL s −1 injection rate), followed by a 15 mL saline flush at the same rate, using a MR-compatible automated injector (Spectris).
Diagnostics
The aim of the present study is to evaluate the intra- and inter-observer agreement in assessing the renal function by means of 99mTc-MAG3 diuretic renography. One hundred and twenty adults were enrolled in the study. One experienced and one junior radiographer processed the renograms twice by assigning manual and semi-automated regions of interest. The differential renal function (DRF, %), time to maximum counts for the right and left kidney (TmaxR-TmaxL, min) and time to half-peak counts (T1/2, min) were calculated. The Bland–Altman analysis (bias±95% limits of agreement), Lin’s concordance correlation coefficient and weighted Fleiss’ kappa coefficient were used to assess agreement. Based on the Bland–Altman analysis, the intra-observer repeatability results for the experienced radiographer using the manual and the semi-automated techniques were 0.2 ± 2.6% and 0.3 ± 6.4% (DRF), respectively, −0.01 ± 0.24 and 0.00 ± 0.34 (TmaxR), respectively, and 0.00 ± 0.26 and 0.00 ± 0.33 (TmaxL...
Quantitation of renal function using MAG3
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 1991
A Ithougha number of investigators have shown strong correlation between MAO3 clearance and or thoiodohippurate (OIH) clearance, there has been no agreement on the exact value for the proportionality constant. Taylor, using a single-injec tion technique with HPLC-purified MAO3, found a value of 0.70 (simul taneous 0â€"90-mmdata) (1). Bubeck found a value of 0.67 using a contin uous-infusion technique with HPLC purified MAO3 in a series of 124 pa tients (2). Single-injection techniques using unpurified commercial kits have led to somewhat lower values, ranging from 0.51 to 0.61 (3â€"5). Whether these differences should be ascribed to the purity of the radio pharmaceutical or to the methodology ofthe studies has been unclear. In this issue, Prenen and co-workers report a value of 047, the lowest yet, using a continuous infusion method with an unpurified commercial kit, and argue that impurities are not significant. Their report will ensure that the de bate continues. ERPF VERSUS GFRâ€"ORBOTH? The two classical physiologic meas ures ofrenal function are inulin clear ance (or GFR) and PAH clearance (or ERPF). Of these two, OFR is more familiar, being approximated (very crudely) by the widely available crc atinine clearance. However, clinicians can learn to monitor renal function using ERPF in much the same way
Acta chirurgica iugoslavica, 2014
The aims of this study in healthy in di vid u als were: a) to im ple ment the In ter na tional Atomic En ergy Agency (IAEA) Soft ware Pack age into anal y sis of tech ne tium-99m mercapto-acetyltriglycine ( 99m Tc MAG 3 ) dy namic scintigraphy, b) to val i date re sults of renogram pa ram e ters against their ref er ence val ues, and c) to com pare dif ferent renogram in di ces of kid ney ex cre tion in or der to as sess whether the clin i cal in for ma tion pro vided by all of them is iden ti cal. Study pop u la tion con sisted of 20 healthy sub jects who were eval u ated by 99m Tc MAG 3 dy namic scintigraphy for kid ney do na tion. The IAEA soft ware was ap plied to pro cess the stud ies. The pa ram e ters an a lyzed were: time to max i mum ac tiv ity (T max ), time to half max i mum (T 1/2 ) of the curves, nor mal ized re sid ual ac tiv ity at 20 min utes (NORA 20), out put ef fi ciency at 20 min utes (OE 20), re sid ual ac tiv ity (RA), elim i na tion in dex (EI), whole kid ney mean tran sit time (MTT), mean parenchymal tran sit time (MPTT) and rel a tive kid ney func tion (RF). Corre spon dence be tween OE 20, NORA 20, RA and EI was eval u ated by Pearson cor re la tion co ef fi cient and lin ear re gres sion anal y sis. The re sults for nor mal kidneys were pre sented as fol lows: T max : 3.4+0.7 min; T 1/2 :6.1+1.5min; NORA20:0.34+0.09;OE20: 93+2.2%; RA: 26+6.2%; EI: 2.2+0.4; MTT: 2.+0.4 min and MPTT: 1.7+0.4 min. Rel a tive func tion for the left and right kid ney was 52% and 48%+2.4%, re spec tively. The ex cel lent agree ment was ob served be tween the ob tained val ues of renogram pa ram e ters and their ref er ence val ues. Sig nif i cant lin ear cor re la tion between pa ram e ters of kid ney ex cre tion was ob tained. The high est cor re la tion was ob served be tween NORA 20 and OE 20 (r = -0.936, p< 0.01). In Con clu sion, the IAEA Soft ware gives re li able val ues of nu mer i cal param e ters of kid ney ex cre tion. Re sults ob tained for nor mal kid neys were al most iden ti cal with pre vi ously re ported ref er ence val ues for MAG 3 pa ram e ters. Only the re sults for MTT and MPTT were sys tem at ically lower than the es tab lished nor mal val ues. NORA 20 highly cor re sponds with OE 20 and could re place the for mer pa ram e ter in the eval u a tion of kid ney drain age. The pre lim i nary re sults sup port the widespread use of IAEA soft ware pack age in or der to stan dard ize the tech nique of dy namic re nal scintigraphy.
European Journal of Radiology, 2005
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 • 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 (Q c = 0.057 ± 0.030 ml/(s 100 g) to Q c = 0.030 ± 0.017 ml/(s 100 g), P < 0.013), of the medullary perfusion (Q m = 0.023 ± 0.018 ml/(s 100 g) to Q m = 0.011 ± 0.006 ml/(s 100 g), P < 0.046) and of the accumulation of contrast media in the medulla (Q a = 0.005 ± 0.003 ml/(s 100 g) to Q a = 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 Q a in the medulla (r 2 = 0.72, P < 0.05), and between the perfusion ratio Q c /Q m and the accumulation Q a in the medulla (r 2 = 0.81, P < 0.05). No significant difference was found in times to peak between both populations despite a trend showing T a 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.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2015
Glomerular filtration rate (GFR) can accurately be determined using (51)Cr-ethylenediaminetetraacetic acid (EDTA) plasma clearance counting but is time-consuming and requires technical skills and equipment not always available in imaging departments. (68)Ga-EDTA can be readily available using an onsite generator, and PET/CT enables both imaging of renal function and accurate camera-based quantitation of clearance of activity from blood and its appearance in the urine. This study aimed to assess agreement between (68)Ga-EDTA GFR ((68)Ga-GFR) and (51)Cr-EDTA GFR ((51)Cr-GFR), using serial plasma sampling and PET imaging. (68)Ga-EDTA and (51)Cr-EDTA were injected concurrently in 31 patients. Dynamic PET/CT encompassing the kidneys was acquired for 10 min followed by 3 sequential 3-min multibed step acquisitions from kidneys to bladder. PET quantification was performed using renal activity at 1-2 min (PETinitial), renal excretion at 2-10 min (PETearly), and, subsequently, urinary excret...
Erciyes Medical Journal, 2018
Objective: In dynamic renal scans, 99m Tc-diethylenetriamine pentaacetic acid (DTPA) is copiously used and it yields information about the renal blood-flow and the excretory capacity. 99m Tc-dimercaptosuccinic acid (DMSA) is used for static renal imaging and can likewise uncover the renal cortical structure. This work was intended to evaluate whether DMSA can be declared as a radiopharmaceutical in dynamic renal scans or not. It also aimed at comparing the outcomes procured from DMSA and with DTPA examinations. Materials and Methods: A comparison of the information gained from the renograms of 47 subjects (normal subjects and subjects with abnormal renal function having: obstructive nephropathy, bilateral nephropathy, hydronephrosis, reduced or non-function kidney, and/or atrophic kidney) who had 99m Tc-DMSA and 99m Tc-DTPA dynamic scintigraphies utilizing the same protocol. Results: A strong positive correlation had come in view on the evaluation of the left kidney, right kidney, and total glomerular filtration rate (GFR) from 99m Tc-DTPA and 99m Tc-DMSA renograms. In addition, the estimation of the time of the peak height from 99m Tc-DTPA and 99m Tc-DMSA renograms for the right and left kidneys demonstrated as non-significant varieties and a strong positive correlation for both the normal subjects and subjects with kidney abnormalities. Conclusion: In the light of the outcomes gained from the present investigation, it could be prescribed that 99m Tc-DMSA can favorably replace 99m Tc-DTPA in dynamic renograms in the case of the renal conditions that had been examined in the present work. As scheduled, this will be cost-effective and time saving and will decrease the radiation dose administered to the subjects. Also, the same qualities of results are accomplished with both radiopharmaceuticals in normal subjects and subjects with abnormal renal function.
Nuclear Medicine Review, 2015
BACKGROUND: The clinical significance of MTT and PTT, determined by deconvolution of renographic curves, is arguable. Their usefulness in diagnosis of obstructive uro-and nephropathy, renovascular hypertension and monitoring of transplanted kidneys is pointed out, but susceptibility of deconvolution methods to errors resulting from "statistical noise" is also stressed. So far there are no reports on normative MTT values for 99m Tc-EC, although such values were already determined for 131 I-OIH, 99m Tc-DTPA and 99m Tc-MAG 3. The aim of this study is an assessment of inter-and intraobserver reproducibility of MTT and PTT for 99m Tc-EC, and determination of normative values for these parameters. MATERIALS AND METHODS: 31 patients (17 women and 14 men aged 19-75, average 44 years) referred for dynamic renal scintigraphy with: unilateral flow impairment (11), unilateral nephrolithiasis (2), control after unilateral lithotripsy (4), moderate hypertension (demographically with > 99% probability of primary hypertension) (4), suspected cirrhosis of one kidney (3), future kidney donors (3), control after abdominal injuries (3), incontinence (1). 42 functionally efficient kidneys were included in the study. Criteria for recognition of a kidney as functionally efficient were:-no earlier history of renal disease, signs of renal damage in basic blood and urine tests, or abnormalities in ultrasonography;-normal result of dynamic renal scintigraphy (in terms of sequential images and renographic curve). MTT and PTT values were determined independently by two operators, using a matrix method for deconvolution of renographic curves. RESULTS: Differences between mean MTT and PTT from two studies by one operator were insignificant and those values were closely correlated (r = 0.99 and r = 0.97, respectively). Differences of values obtained by both operators were practically insignificant for MTT (r = 0.93), and significant for PTT (r = 0.81 and p < 0.001). These differences do not disqualify that processing method. The upper limits of normative values of MTT and PTT were based on the results from first study performed by more experienced operator-200 s and 170 s, respectively. CONCLUSIONS: The procedure of processing dynamic renal scintigraphy used in this study is reproducible. Normative values of MTT and PTT for 99m Tc-EC were established as 200 s and 170 s, respectively. An attempt to optimize and standardize the technique of determining parenchymal ROI in a matrix deconvolution method, followed by an evaluation of clinical usefulness of these parameters in the diagnosis of chosen renal function impairments would be a logical continuation of this initial research.
2002
Determinations of different methods of measurement of uptake of ""Tc-DTPA using scintigraphy of glomerular filtration rate (GFR) were made from 29 studies on 10 healthy beagle dogs. GFR was measured by calculating the percentage dose uptake (integral method) and rate of uptake (slope method) of 99mTc-DTPA using manual kidney regions of interest (ROI) and automatic kidney and background ROIs at different time periods of the uptake phase. These results were compared using linear regression analysis to the GFR obtained from 99mTc-DTPA plasma clearance using multiple blood samples. The best correlation coefficient between percentage DTPA uptake and GFR by DTPA clearance (r = 0.84, P < 0.001) was derived from time intervals between 30s-120s with a perirenal background ROI at 1 or 2 pixels out from the kidney ROI using automatic kidney ROI at 20% threshold. With the slope method, the best correlation coefficient (r = 0.85, P < 0.001) was obtained from time intervals between 30s-peak with the background ROI at 2 pixels out from the kidney ROI using automatic ROI at 35% threshold. The offset was higher, and the correlation varied more with different ROIs and the method was unreliable at time intervals extending beyond the peak radioactivity. Manual kidney ROIs with automatic background ROIs had slightly lower correlations. With DTPA renography both integral and slope uptake method with automatic kidney and background ROIs are accurate methods to estimate the GFR, but that the integral method is much more stable to variations in ROI size and the duration of the uptake phase of the renogram.