Assessment of split renal function with 99mTc-aprotinin

The aim of this work is to correlate the net kidney uptake of 99mTc-aprotinin (TcA) in 103 subjects with separate effective renal plasma flow (ERPF) and some blood chemistry parameters at 90, 180, and 360 min postinjection both in the normal and diseased kidney. Correlations found with separate ERPFs are highly significant at any time (P less than 0.001). However, although the slope of the regression line is steeper at 180 min, r tends to deteriorate slightly with time postinjection and a higher intercept on the y axis; this pattern is more pronounced if diseased kidneys are considered separately. The following are probably related to the renal handling of TcA: Early scans better reflect blood flow to the kidney, while later scans are more related to the metabolism/excretion tubular mechanisms; correlations found with urea, creatinine, urea clearance, and creatinine clearance are highly significant at any time; in 20 additional patients with diseased kidneys, renal uptake measurements done 360 min postinjection first with TcA and then with DMSA showed better correlations with ERPF employing TcA. Our results indicate that TcA is a feasible indicator of split renal function even at 90 min postinjection when a scan is easily carried out on an outpatient basis.     

99mTc-MAG3: Dynamic studies in patients with renal disease

Animal studies have suggested that ^99mTc-mercapto-acetylglycyl-glycyl-glycine (^99mTc-MAG3) might be suitable for the determination of the renal plasma flow (RPF) because of its high renal clearance. In this study ¹³¹I-orthoiodohippurate (¹³¹I-OIH) and ^99mTc-MAG3 (labeling always >95%) were administered simultaneously in 11 patients (creatinine clearance ranging from 14 to 130 ml/min per 1.73 m²) to measure effective RPF(ERPF) using the standard technique (UV/P). Glomerular filtration rate (GFR; clearance of ¹²⁵I-thalamate, ¹²⁵I-OT) was also measured. The mean ratio of ^99mTc-MAG3 clearance to ¹³¹I-IOH clearance was 0.55±0.02 (SEM), P<0.01, n=16, and was independant of GFR and ERPF. To study this difference in renal handling ofthe radiopharmaceuticals, renal extractions by the right kidney were determined in another six patients after a single shot of the agents. Renal extraction of ^99mTc-MAG3 was 0.60±0.03 after 5 min, and 0.41±0.08 after 30 min. Renal extraction of ¹³¹I-OIH amounted to 0.86±0.04 and 0.77±0.03, respectively. Using renal extractions of 0.41 and 0.77, respectively, it appeared that calculated renal plasma flows measured simultaneously with ^99mTc-MAG3 and ¹³¹I-OIH were similar. Protein binding 30 min after the priming dose was 66% for ^99mTc-MAG3 and 47% for ¹²³I-OIH. We conclude that in spite of a high renal clearance (ratio to ¹²⁵I-OT clearance 2.69±0.27), ^99mTc-MAG3 seems unsuitable for an accurate determination of the RPF. This conclusion is strongly supported bythe observation that the ratio of ^99mTc-MAG3 to ¹³¹I-IOH clearance markedly decreased from 0.66 to 0.32 in a patient with an increase in urinary protein loss.     

Technetium 99m mercaptoacetyltriglycine gamma camera clearance calculations: methodological problems

Major sources of errors in the gamma-camera methods for the calculation of renal clearance are the accuracy of background correction for obtaining the true renal time-activity curve and the validity of the externally recorded pre-cordial activity as an estimate of the plasmatic time-activity curve. With technetium 99m mercaptoacetyltriglycine (^99mTc-MAG3), because of its high protein plasma binding, one could expect minimal extravascular diffusion and hence a more accurate externally detected plasmatic curve. The high extraction rate should reduce the influence of the background, but, on the other hand, the effect of hepatobiliary excretion on the calculation of renal clearance might be significant. Our results suggest that the hepatobiliary excretion of^99mTc-MAG3 does not influence the gamma-camera renal clearance determination, even in patients with low renal function. However, the pre-cordial curve does not reflect accurately the plasmatic disappearance curve; its calibration with a single plasma sample taken at the 20th min is responsible for significant errors, probably because of an unfavourable ratio between the intravascular and extravascular activities at the 20th min. Offprint requests to: M. TondeurParts of this work have been presented at the 17th Annual Meeting of the British Nuclear Medicine Society, London, in April 1989.     

Technetium-99mL,l-ethylenedicysteine clearance and correlation with iodine-125 orthoiodohippurate for the determination of effective renal plasma flow

Technetium-99mL,l-ethylenedicysteine (^99mTcL,l-EC) is a new renal tubular tracer that allows the determination of the effective renal plasma flow (ERPF). The aim of this study was to derive simplified methods for the estimation of^99mTc-L,l-EC clearance using one or two plasma samples after bolus injection. Fifty-nine multiple plasma dual-tracer samples (nine samples from 5 to 120 min after injection) were obtained after injection of kit-formulated^99mTc-L,l-EC and iodine-125 orthoiodohippurate (01H). The studies were performed in 25 stable and 24 unstable transplant recipients, in five patients with renal insufficiency (four on chronic haemodialysis) and in five normal volunteers. This allowed a wide range of renal function values to be covered, with ERPF (estimated by 01H clearance) ranging from 25.4 to 604.0 ml/min. The reference^99mTc-L,l-EC clearance, as calculated from the multisample model, could be estimated from two samples at 15 and 90 min with an error of 11.3 ml/min and from one sample at 90 min with an error of 17.8 ml/min. Using appropriate linear regression analysis, ERPF could be estimated by the two- and one sample^99mTc-L,l-EC clearance with an error of 24.2 and 22.8 ml/min, respectively. In conclusion,^99mTc-L,l-EC clearance can be accurately estimated by simplified one or two-sample methods. Moreover, these methods can be used to estimate ERPF with an error that remains acceptable for clinical purposes.     

Reappraisal of single-sample and gamma camera methods for determination of the glomerular filtration rate with99mTc-DTPA

The aim of this study was to assess the clinical validity of single-sample methods and gamma camera uptake methods with 99mTc-DTPA for the estimation of the glomerular filtration rate (GFR). The study was performed in 50 patients with various degrees of renal function (29 males and 21 females; age 27-90 yrs; serum creatinine level 0.34-6.49 mg/dl). As a reference the "true" GFR (GFRt) was determined from plasma clearance by means of the two compartment model curve fitting 10 plasma samples. The GFRt of more than 30 ml/min in 46 patients was compared to the GFR which was estimated with 7 single-sample methods, two gamma camera uptake methods and 24-hour endogenous creatinine clearance (24hCcr). Close correlation was observed in all single-sample methods. The highest linear correlation was observed in the Christensen and Groth's method rewritten by Watson for a 180-min plasma sample (r = 0.991, see = 5.84 ml/min). The smallest random error was observed in the Groth and Aasted's method for a 180-min plasma (r = 0.989, see = 4.31 ml/min/1.73 m2). Our method was lowest in % absolute difference analysis (mean = 4.10%). The gamma camera uptake methods correlated significantly with the GFRt (r = 0.746-0.774), but were less reliable than any of the single-sample methods (see = 15.41 ml/min-19.14 ml/min). The lowest correlation was observed in the 24hCcr (r = 0.698, see = 50.76 ml/min/1.73 m2). The single-sample method was more accurate than the gamma camera method, and the gamma camera method was more accurate than 24hCcr. The single-sample method should be recommended for the accurate determination of the GFR with 99mTc-DTPA in a patient with mild to moderate renal dysfunction.     

Cardiac and pleuropulmonary AL amyloid imaging with technetium-99m labelled aprotinin

Antiproteases are known to be present in amyloid deposits. We evaluated the possibility of using an anti-serine protease (aprotinin) labelled with technetium-99m (TcA), usually employed as a cortical renal tracer, for the imaging of amyloid deposits. Because of the known high uptake of TcA by the kidneys, we limited our analysis to extra-abdominal amyloid localizations. We report the scintigraphic findings observed in 24 patients with light chain amyloidosis (AL) and one with a hereditary form who were known or suspected to have extra-abdominal involvement. Planar scans obtained 100 min after i.v. TcA administration showed myocardial accumulation in 11 patients, pleuropulmonary accumulation in nine, pericardial accumulation in two and localization in the neck region (thyroid, salivary glands and tongue) in eight. TcA scintigraphy was negative in five patients without clinical or laboratory evidence of extraabdominal involvement, as well as in 12 control group patients with cardiac and renal diseases. These preliminary results indicate TcA to be a low-cost, readily available radiopharmaceutical for imaging of extra-abdominal involvement in AL type amyloidosis.     

Estimation of technetium 99m mercaptoacetyltriglycine lasma clearance by use of one single plasma sample

Recent studies have shown that technetium 99m mercaptoacetyltriglycine (MAG-3) is a suitable replacement for iodine 131 or 123 hippurate in gammacamera renography. Also, the determination of its clearance is of value, since it correlates well with that of hippurate and thus may be an indirect measure of renal plasma flow. In order to simplify the clearance method we developed formulas for the estimation of plasma clearance of MAG-3 based on a single plasma sample and compared them with the multiple sample method based on 7 plasma samples. The correlation to effective renal plasma flow (ERPF) (according to Tauxe's method, using iodine 123 hippurate), which ranged from 75 to 654 ml/min per 1.73 m², was determined in these patients. Using the developed regression equations the error of estimate for the simplified clearance method was acceptably low (18–14 ml/min), when the single plasma sample was taken 44–64 min post-injection. Formulas for different sampling times at 44, 48, 52, 56, 60 and 64 min are given, and we recommend 60 min as optimal, with an error of estimate of 15.5 ml/min. The correlation between the MAG-3 clearances and ERPF was high (r = 0.90). Since normal values for MAG-3 clearance are not yet available, transformation to estimated ERPF values by the regression equation (ERPF=1.86 × C_MAG-3 + 4.6) could be of clinical value in order to compare it with the normal values for ERPF given in the literature. Offprint requests to: R. Müller-Suur     

Technetium-1,2-dihydroxy-1,2-bis(dihydroxyphospinyl)ethane (99mTc-DHPE). A promising new skeletal imaging agent

^99mTc-sodium pertechnetate was reduced and complexed with 1,2-dihydroxy-1,2-bis(dihydroxyphosphinyl)ethane (DHPE) with a yield higher than 95%. When administered to rats, ^99mTc-DHPE demonstrated very good skeletal uptake, a high clearance from blood to the bones a low concentration in muscles and other organs, satisfactory biological stability and a clearance mainly through the kidneys. The biodistribution of ^99mTc-DHPE in rats compared to that of ^99mTc-methylenediphosphonate (^99mTc-MDP) at 2 and 24 h post injection, showed higher skeletal uptake, substantially higher blood clearance, but also higher concentration in muscles which, however, caused no significant degradation in image quality. These characteristics suggest that ^99mTc-DHPE is a promising new skeletal imaging agent.     

Comparison of glomerular filtration rate by Gates method with Cockroft Gault equation in unilateral small kidney

Objective

To compare the glomerular filtration rate (GFR) by ^99mTc DTPA scan and the Cockroft Gault method in unilateral small kidney.

Materials and methods

The present study was conducted in the Department of Nuclear Medicine at the Sher-i-Kashmir Institute of Medical Sciences (SKIMS), India from July 2007 to April 2011. The present study included 47 patients with a diagnosis of unilateral small kidney on ultrasound. Out of 47 patients, 21 (44.7%) were males and 26 (55.3%) were females. Image processing was done using camera based methods. The GFR was automatically calculated by a software in a commercially available computer according to the Gates algorithm. The predicted creatinine clearance was calculated according to the Cockroft and Gault equation.

Results

Mean total GFR by DTPA Gates method was 73.6 ± 18.6 ml/min and by the Cockroft Gault (CG) method was 79.8 ± 32.2 ml/min. The difference was statistically insignificant indicating an agreement between both the methods in measuring GFR.

Conclusions

To discuss the advantages of isotopic renography, CG cannot give individual kidney GFR and so is not of much use in the unilateral small kidney wherein the main aim is to know the function of the individual kidneys. Furthermore because of low cost and less radiation burden, this test might be preferred for routine practice in nuclear medicine.     

Contrast media clearance in a single kidney measured on multiphasic helical CT: results in 50 patients without acute renal disorder.

OBJECTIVE: Single kidney contrast media clearance was measured using multiphasic CT in patients without acute renal disorder. The aim of this study was to answer two questions. First, how accurate is CT in measuring contrast media clearance compared with plasma clearance? Second, is the accuracy of CT clearance measurements dependent on the timing of CT scans with respect to the contrast media injection? SUBJECTS AND METHODS: Fifty adult patients without acute renal disorder were included in this study. Each patient underwent CT for clinical indications. The CT protocol consisted of an unenhanced scan and three contrast-enhanced scans 45, 75, and 105 sec after starting an injection of 120 mL of iopromide using an injection rate of 3 mL/sec. All scans included both kidneys. As a reference, plasma clearance of contrast media was determined as a slope clearance by measuring iodine concentration in eight blood specimens up to 8 hr postinjection. RESULTS: CT clearance was calculated three times for each patient, including early CT clearance, 45-75 sec postinjection; late CT clearance, 75-105 sec postinjection; and overall CT clearance, 45-105 sec postinjection. An overall CT clearance yielded the best correlation with plasma clearance with a correlation coefficient of r = 0.84 and a regression line of y = 7.5 + 0.94x. The mean difference was -3 mL/min (95% confidence interval, -35 to 29 mL/min). CONCLUSION: CT clearance calculated from data acquired with a minimally modified diagnostic abdominal CT protocol was well correlated with the reference method in determining contrast media clearance for patients without acute renal disorders. The presented method can be used to calculate single kidney contrast media clearance in patients receiving contrast-enhanced abdominal CT for clinical indications.     

Renal and extrarenal handling of a new imaging compound (99m-Tc-MAG-3) in the rat

We investigated the renal clearance, the extrarenal clearance, the biodistribution, the plasma extraction ratio and the imaging quality on a scintillation camera of a new substance: ^99mTc-mercaptoacetyltriglycine (MAG-3) in rats. Simultaneously ¹²⁵I-hipputate (OIH) and ⁵¹Cr-EDTA were used as reference substances. In scintillation camera studies, ¹²³I-hippurate served as reference. MAG-3 was prepared by kit labelling without further purification, as it would be used in clinical studies. However in three separate rats, HPLC purified MAG-3 was used. High renal clearance and extraction ratio was found but these were less than that for OIH (1.95 ml/min per 100 g BW vs 2.76 ml/min per 100 gBW and 64% vs 85% respectively). The extrarenal clearance was higher for MAG-3 than for OIH (0.20 ml/min per 100 g BW vs 0.04 ml/min per 100 g BW), presumably because of bile excretion. HPLC purification increased the renal excretion of MAG-3: the clearance was 2.53 ml/min per 100 g BW, the extraction fraction 75%, but the extrarenal clearance was unchanged. The imaging quality was comparable to that of ¹²³I-hippurate in early pictures, but extrarenal activity, presumably representing bile, was observed in late pictures. We conclude that MAG-3 has some potential for the replacement of OIH but clinical studies are necessary to test whether the same conditions and limitations exist in humans.     

Kinetics of Tc-99m hexakis t-butyl isonitrile in normal and ischemic canine myocardium

Hexakis ^99mTc-tertiary butyl isonitrile (^99mTc-TBI) was studied as a cardiac perfusion imaging agent in nine dogs with partial occlusion of the LAD. Thirty min after applying the stenosis, ^99mTc-TBI was injected into the right atrium (RA) in five dogs and left atrium (LA) in four dogs. Normal and ischemic zone regional myocardial ^99mTc-TBI activites were monitored continuously for 4 h. Dogs with LA injections had minimal and equivalent 4 h fractional clearance from the normal and ischemic zones. Dogs with RA injections had minimal, but significantly lower 4 h fractional ^99mTc clearances in the ischemic zone (0.08±0.08) compared to the normal zone (0.16±0.07, P<0.05). The delayed ischemic zone clearance is probably due to the high initial lung uptake observed after RA injection. Despite the differences in clearance, this minimal amount of redistribution could not be detected on gamma camera images. The minimal myocardial washout and redistribution, and the 140 keV gamma make ^99mTc-TBI a promising cardiac perfusion imaging agent.Dr. Okada is an Established Investigator of the American Heart Association     

Evaluation of 123I-orthoiodohippurate single kidney clearance rate by renal sequential scintigraphy in a large cohort of likely normal subjects aged between 0 and 18 years

Purpose Age-related values of ¹²³I-orthoiodohippurate (OIH) single kidney clearance rate (Cl) were estimated in a large cohort of likely normal children aged between 0 and 18 years. Methods Among 4,111 children examined in the past 10 years, 917 were selected with the following inclusion criteria: (a) mild ultrasonographic hydronephrosis with right differential renal function (DRF) <53% and >47% (498 pts), (b) known or suspected urinary tract infection with normal ultrasound, serum creatinine and DMSA and DRF <53% and >47% (419 pts). ¹²³I-OIH-Cl was assessed using a validated gamma camera method. Children were divided into 21 age classes: from 0 to 2 years, eight 3-month classes; from 2 to 14 years, twelve 1-year classes; from 14 to 18 years, one 4-year class. Results Cl, plotted against age, was fitted using an increasing function (). Mean ¹²³I-OIH-Cl of 1,834 kidneys was 306±22 ml/min/1.73 m² BSA. Mean ¹²³I-OIH-Cl of the right and left kidneys was 307±23 and 305±22 ml/min/1.73 m² BSA, respectively (p<0.002). The best-fitting ¹²³I-OIH-Cl growing function was: Cl=311−230e−0.69×Age (months). ¹²³I-OIH-Cl improved progressively starting from birth, reaching 96% and 98% of the mature value at 1 and 1.5 years, respectively. ¹²³I-OIH-Cl at birth (age=0) was 81 ml/min/1.73 m² BSA. After 18.6 days of life, the renal function had doubled its starting value, and it reached a plateau of 311 ml/min/1.73 m² BSA at 2 years. Conclusion This work represents a systematic evaluation of ERPF by a gamma camera method in a large cohort of selected likely normal paediatric subjects. This work is written in memory of Prof. Ugo Meldolesi, our nephrology nuclear medicine mentor and friend.     

90-minute 99mTc-MDP scintigraphy and 131I-hippuran renography in recently allotransplanted kidneys: Evaluation of renal ischemia

Renal ischemic damage in 31 transplanted kidneys was evaluated by renal scintigraphy with ^99mTc-methylene diphosphonate and ¹³¹I-hippuran renography. The renal uptake of phosphate was monitored for 100 s at 10-min intervals during 90 min following injection. The average uptake of radioactivity in the graft on the 60-, 70-, 80-, and 90-min scintigram was calculated. Grafts with an average uptake of ^99mTc-MDP of 150% or below had a significantly more frequent onset of function within the first 3 days following operation than grafts with an average uptake above 150%. Renography was shown to be an equally good method for predicting the onset of function. The success rate (correct prediction of onset of function) was almost equal for the two methods, but in 11 patients the results of the two methods diverged. An obvious degree of overlap limits the usefulness of both methods in any one particular patient. It is concluded that renal scans with ^99mTc-MDP and ¹³¹I-hippuran renography are complementary in the assessment of ischemic damage following transplantation.This study was approved by the Committee on Investigations/Activities involving Human Subjects for the Copenhagen County, Approval no. 164Other participants in the study were: Jan Fogh, Thomas Gjørup, Ole J. Hartling, and Steen Levin Nielsen     

99mTc-DTPA and 99mTc-DMSA renal gamma imaging in the surveillance of patients with conduit urinary diversion

We studied renal anatomy and function using ^99mTc-2-3 dimercaptosuccinic acid (DMSA) and ^99mTc-diethylenetriaminepentaacetic acid (DTPA) in 27 patients with conduit urinary diversion. In this condition, free ureteral reflux is often associated with bacteriuria, and these factors are thought to precipitate progressive renal deterioration. Gamma-camera images provided valuable information concerning the structure of the renal parenchyma, the function of individual kidneys and possible ureteral obstruction, thus helping us to decide whether or not to instigate further treatment. The information gained using renal gamma imaging with ^99mTc-DTPA and ^99mTc-DMSA was complementary and partly overlapping. We preferred the use of ^99mTc-DTPA because of its ability to visualise the ureters and the region of ureteroconduit anastomosis. Using diuretic medication, we were able to differentiate true ureteral obstruction from atony in 9 patients using ^99mTc-DTPA.     

Transplant renography: 99m-Tc-DTPA versus 99m-Tc-MAG3. a preliminary note

^99mTc-MAG3 has been proposed as a replacement for both ¹³¹I-hippuran and ^99mTc-DTPA on clinical grounds. We undertook a prospective preliminary study to ascertain whether ^99mTc-MAG3 works better than ^99mTc-DTPA in the follow up of renal transplant recipients. Seventeen patients (21 renograms each MAG3 and DTPA) were studied, together, with a reference group of 10 patients in whom MAG3 and Hippuran clearance rates were determined simultaneously. As expected, ^99mTc-MAG3 analog images were excellent and ^99mTcMAG3 clearance correlated very well with ¹³¹I-hippuran clearance (r=0.978). MAG3 values were 60% of hippuran values. However, when the corresponding renographic and perfusion findings were faced with different diagnostic challenges, such as post transplant renal failure and rejection, ^99mTc MAG3 did not differ from ^99mTc-DTPA in a significant way. ^99mTc-DTPA was superior to ^99mtc-MAG3 in one case of rejection.     

Accuracy of plasma sample methods for determination of glomerular filtration rate with<Superscript>99m</Superscript>Tc-DTPA

The plasma sample method following a single injection of radioactive markers has been proved to be simple and accurate for the determination of glomerular filtration rate (GFR) in clinical practice. The aim of this study was to assess clinical accuracy of single-, two- and multi-sample methods. METHODS: The study was performed on 50 patients with various degrees of renal dysfunction (29 males and 21 females; aged 27 to 90 years). As a reference the true GFR (GFRt) was determined by means of the two-compartment model curve fitting 10 plasma samples following a single-injection of 99mTc-DTPA. The GFRt was compared to the GFR estimated by the Christensen and Groth's single-sample (GFRcg), two-sample (GFR2s) and multi-sample (GFRm) between 75 and 300 min after the injection. The GFRs by two- and multi-sample methods were determined with the slope and intercept algorithm and its overestimation was corrected by Brochner-Mortensen's formula. RESULTS: In 49 patients with GFR between 12 and 169 ml/min/1.73 m2, the standard deviation of difference (95% limits of agreement) between GFRt and GFRcg at 180 min was 6.513 ml/min/l73 m2 (-16.5 approximately 9.5 ml/min/1.73 m2), which was somewhat closer than 7.311 ml/min/1.73 m2 (-12.5 approximately 16.5 ml/min/1.73 m2) in GFR2s in slow clearance phase at 120 min and 240 min. However, the single-sample method tended to show some scattering in GFR below 30 and above 140 ml/min/ 1.73 m2. On the contrary, the 2-sample method tended to be scattered in GFR above 120 ml/min/ 1.73 m2. CONCLUSION: In view of its accuracy and technical simplicity, the single-sample method is first choice in a routine practice. The two-sample method is essential of choice for a patient in whom the GFR is expected to be below 30 ml/min/1.73 mi2. These two methods may be chosen selectively in dependence on the preserved renal function which is expected at time of the test.     

Measurement of separate kidney clearance by means of 99mTc-DTPA complex and a scintillation camera

A new radioisotopic method of determining the separate glomerular clearance of the kidneys is described. After injection of ^99mTc-DTPA, the data from a scintillation camera are recorded by computer. The renal curves are corrected for extrarenal activity and the plasma curve is obtained from a precordial curve. At each instant the slope of the renal curve divided by the corresponding plasma concentration gives the separate clearance value, in the period extending from 80 to 180 s after injection of the tracer. The error and correction factors introduced are discussed. Normal values are established on 25 patients and correspond to inulin clearance values. Left kidney: 60 ml/min (SD=13). Right kidney: 57 ml/min (SD=12). The method is simple for the patient, takes only 20 min, is not dangerous, is particularly applicable to young children and can be repeated frequently in the same patient.     

99mTc-MAG3, a new renal imaging agent: Preliminary results in patients

^99mTc-mercaptoacetyltriglycine (MAG₃) is a new renal radiopharmaceutical which has been shown to have biological properties similar to¹³¹I-hippurate (OIH) in animals and volunteers.^99mTc-MAG₃ has now been compared with¹³¹I-orthoiodohippurate (OIH) in a group of patients with varying degrees of renal impairment. In all cases, the^99mTc-MAG₃ images were superior regardless of serum creatinine. Selected examples are illustrated including scans and renogram curves in a normal volunteer, transplant patients with creatinines of 9.8 mg/dl and 2.6 mg/dl respectively, and a furosemide study in a patient with questionable obstruction. Our preliminary results suggest that^99mTc-MAG₃ performs well in patients with impaired renal function and may well provide an acceptable replacement for OIH. A kit formulation has been developed and will soon be undergoing clinical evaluation.     

Influence of whole-body vibration on biodistribution of the radiopharmaceutical [99mTc]methylene diphosphonate in Wistar rats

Abstract

Purpose: The radionuclide bone scan is the basis of skeletal nuclear medicine imaging. Bone scintigraphy is a highly sensitive method for indicating disease in bone. Mechanical stimulation in the manner of whole-body vibration (WBV) appears beneficial to the maintenance and/or enhancement of skeletal mass in individuals. The aim of this work was to evaluate the effect of WBV on the biodistribution of the radiopharmaceutical [^99mTc]methylene diphosphonate (^99mTc-MDP ) in Wistar rats.

Materials and methods: In the biodistribution analysis, animals were anesthetized with sodium thiopental, the radiopharmaceutical ^99mTc-MDP was administered via ocular plexus and after 10 min the animals were submitted to vibration of 20 Hz (1 min) in an oscillatory platform. Following, the animals were sacrificed, the organs were isolated, the radioactivity determined in a well counter, and the percentages of radioactivity per gram (%ATI/g) in the organs were calculated. An unpaired t-test following Welch test (p < 0.05) was done for statistical analysis of the results.

Results: The biodistribution was significantly (p < 0.05) decreased in kidney, bone, lung, stomach, prostate and bowel.

Conclusion: The analysis of the results indicates that the vibration could produce metabolic alterations with influence in the uptake of the radiopharmaceutical ^99mTc-MDP in bone, stomach, bowel, prostate, kidney and bladder.