TUBULAR SECRETION (Tc-99m MAG3)

Transcription

1 NUCLEAR MEDICINE SERVICES SUBJECT: RENAL MAG-3 ONLY STUDY TUBULAR SECRETION (Tc-99m MAG3) Overview Indications Tc-99m MAG3 is a technetium-labeled compound with many of the functional properties of I-131 Hippuraite. After IV injection, it is highly protein-bound and excreted primarily by tubular secretion, with no retention in normal kidney parenchyma. Renogram curves for MAG3 are essentially the same as for iodohippurate, with the advantage of superior image quality and decreased radiation exposure to the patient. Tc-99m MAG3 studies image the radiopharmaceutical as it passes through the vascular system, renal tubular cells, tubular lumens, and the renal collection system. This series of images allows the sequential evaluation of renal perfusion, renal clearance by tubular secretion, renal parenchymal transit time, and passage of urine through the renal collection system. In addition, the study provides high contrast images for the evaluation of renal anatomy. 1. Evaluate and assess renal perfusion and function. 2. Evaluate renal failure. 3. Evaluate renal trauma. 4. Evaluate renal hypertension. 5. Evaluate renal transplant. 6. Detection and evaluation of renal collection system obstruction. Contraindications Radiographic contrast agents may interfere with kidney function. If contrast studies have been performed, the real scan should deferred for 24 hours. If the patient has undergone renal angiography or angioplasty, the study should be deferred for 3 days, if clinically feasible. Examination Time Vascular Flow and Function with Lasix: minutes. Patient Preparation Drink 32 ounces of water starting 2 hours before the appointment, or hydrate according the sedation guidelines for pediatric sedation cases. Good hydration is required for all renal studies (urine flow rate of more than 1 ml/min). If patient has inadequate hydration, have them drink 300 to 500 ml of water or juice and then begin in 30 to 45 minutes. The patient should void before beginning the study, or have a urinary catheter placed. Note: If the patient has an indwelling urinary catheter, check with the nuclear physician about whether it should be clamped for the duration of the study. 1

2 PEDIATRICS: If sedation is ordered: NPO solids for 6 hours. Clear liquids only up to 2 hours before procedure. NPO TOTALLY 2 hours before procedure. I.V. fluids to deliver 15 mls/kg over 30 minutes beginning at least 15 minutes before injection. I.V. fluids to continue at rate of 200 ml/kg/24 hr as maintenance for remainder of study. Place urinary bladder catheter prior to isotope injection. Equipment & Energy Window Gamma camera: Large field of view Collimator: VXGP, LEHR Energy window: 20% window centered at 140 kev. Radiopharmaceutical, Dose, & Technique of Administration Radiopharmaceutical: Tc-99m MAG3. Dose: 3 mci Tc-99m MAG3 Adjust dose according to the pediatric dose chart Technique of Administration: Bolus delivery Patient Position & Imaging Field Patient position: Supine. Place camera facing the lower back with kidneys in the top third of the field of view (FOV). Transplant: Supine with camera anterior to patient s abdomen with kidney in the middle of FOV. (Look at surgical site for placement under the camera, or if unsure, have the patient place hand over kidney. Positioning: Find the xyphoid with your hand and place a radioactive source over the xyphoid. On the acquisition screen you want the source to show up about ½ to 1 inch below the top of the screen. You can also see where elbows are on the screen. They should be about 1/3 the way down the screen. Run the source down the sides of the patient to make sure that they are all the way in the field of view. Double check that camera is as close to patient as possible. ACQUISITION PROTOCOLS A. VASCULAR FUNCTION ONLY Place IV site, obtain history, weight/height, and get medication list. 1. Acquire - MAG3 pre-syringe static image - 128X128 matrix 60 seconds MAG3 FLOW 1 Dynamic - 128X128 matrix 1 sec/frame 60 frames MAG3 FLOW 2 - Dynamic - 128X128 matrix - 5 sec/frame -360 frame MAG3 post-syringe - static image 128X128 matrix 60 seconds. To acquire the needed bolus MAG3 flow studiesa. First, check the IV site to make sure that it is patent. b. Start camera c. Push as hard as possible on the syringe to get the dose in quickly 2

3 d. Follow immediately with a bolus of the saline. (10 ml of normal saline.) B. VASCULAR FUNCTION WITH LASIX Contraindications: 1. Check for possible allergy to furosemide (Lasix) 2. Radiographic contrast agents may interfere with kidney function. If contrast studies have been performed, the renal scan should be deferred for 24 hours. If the patient has undergone renal angiography or angioplasty, the study should be deferred for 3 days. Place IV site, obtain history, weigh/height and get medication list. ADULTS 1MG/KG (MAX DOSEIS 40 MG) PEDIATRIC 1 MG/KG INJECT AT 20MIN POST START OF EXAM MAG-3 pre-syringe static image - 128X128 matrix 60 seconds MAG3 FLOW 1 Dynamic - 128X128 matrix 1 sec/frame 60 frames MAG3 FLOW 2 - Dynamic - 128X128 matrix - 5 sec/frame -360frames Starting around frame 100 (or when urine is visualized in the ureters), slowly inject lasix over 1 to 2 minutes. Record the frame that you start injecting it on for later use. MAG3 post-syringe - static image 128X128 matrix 60 seconds Note: Normal halftime clearance is approximately 10 minutes: abnormal is over 20 minutes; and between 10 and 20 minutes is often considered indeterminate. C. CAPTOPRIL ENHANCED VASCULAR FUNCTION (Angiotensin Converting Enzyme (ACE) Inhibitor Renal Study) Contraindications Allergy to furosemide (lasix). Radiographic contrast agents may interfere with kidney function. If contrast studies have been performed, the renal scan should be deferred for 24 hours. If the patient has undergone renal angiography or angioplasty, the study should be deferred for 3 days, if clinically feasible. 3

4 Administration of Captopril Chronic administration of ACE inhibitors and diuretics may decrease the sensitivity of the test. Stop ACE inhibitors for 48 hours prior and no diuretics on the day of exam. Record the patients weight and height. Place IV (in AC if possible). a. Stop lisinopril and enalaprilat for at least 1 week. b. Patient must refrain from food for at least 4 hours prior to the exam. c. Patient must be well hydrated prior to the exam (1 quart of water starting 2 hours before the exam. Captopril: 50 mg orally(tablet to be ground with mortar and pestle, and suspended in water): (Since food in thegastrointestinal tract delays absorption, the patient should fast for 4 hours) Have the patient lay down on bed. Record the patient s blood pressure prior to taking Captopril and then every 15 minutes for 60minutes after Captopril is given to monitor effect of Captopril. IMAGING 5 minutes before last BP is to be taken set up camera to acquire the pre MAG-3 syringe counts. MAG-3 pre-syringe static image - 128X128 matrix 60 seconds After the hour is up from the administration of Captopril take a last BP. Positioning: Find the xyphoid with your hand and place a radioactive source over the xyphoid. On the acquisition screen you want the source to show up about ½ to 1 inch below the top of the screen. You can also see where elbows are on the screen. They should be about 1/3 the way down the screen. Run the source down the sides of the patient to make sure that they are all the way in the field of view. Acquire - LASIX GIVEN IMMEDIATELY POST MAG-3 INJECTION. MAG3 FLOW 1 Dynamic - 128X128 matrix 1 sec/frame 60 frames MAG3 FLOW 2 - Dynamic - 128X128 matrix - 5 sec/frame -360 frames MAG3 post-syringe - static image 128X128 matrix 60 seconds. To acquire the needed bolus MAG3 flow studiese. First, check the IV site to make sure that it is patent. f. Start camera g. Push as hard as possible on the syringe to get the dose in quickly h. Follow immediately with a bolus of the saline. (10 ml of normal saline.) 4

5 If patients BP drops too low from the Captopril have patient lie down and start giving them a saline drip with 250 ml bag of normal saline. Inform nuclear physician of patient s status. Continue to monitor BP until it returns to normal. Captopril studies need to be started right at the 1-hour post Captopril dosing mark. If the ACE inhibitor renal study is abnormal, a baseline Tc-99m MAG3 renal study should be performed later when the patient has been off ACE inhibitors for at least 2 days. Data Processing Process according to the protocol for the EBW. Principle Radiation Emission Data - Tc-99m (36) Physical half-life = 6.01 hours. Radiation Mean % per disintegration Mean energy (kev) Gamma Dosimetry - Tc-99m-MAG3 (9) Organ rads/10 mci mgy/370 MBq Bladder wall 4.8 hour void Ovaries 4.8 hour void Testes 4.8 hour void Kidneys Total body Liver References 1. Schaap GH, Alferink THR, dejong RBJ, et al: Tc-99m-MAG3: Dynamic studies in patients with renal disease. Eur J Nucl Med 14:28-31, Blaufox MD, Middleton ML, Bongiovanni J, et al: Cost efficacy of the diagnosis and therapy of renovascular hypertension. J Nucl Med 37: , Pediatric nuclear medicine council: The "well tempered' diuretic renogram: A standard method to examine the asymptomatic neonate with hydronephrosis or hydroureteronephrosis. J Nucl Med 33: , Muller-Suur R, Bois-Svensson I, Mesko L: A comparative study of renal scintigraphy and clearance with technetium-99m-mag3 and iodine-123-hippurate in patients with renal disorders. J Nucl Med 31: , Taylor A, Ziffer JA, Steves A, et al: Clinical comparison of I-131-OIH and kit formulation of Tc-99m mercaptoacetyltriglycine. Radiology 170: , Gupta MK, Bomanji JB, Waddinton W, et al: Technetium-99m-L,L-ethylenedicysteine scintigraphy in patients with renal disorders. Eur J Nucl Med 22: , Eshima D, Taylor A: Technetium-99m (Tc-99m) mercaptoacetyltriglycine: Update on the new Tc-99m renal tubular function agent. Sem Nucl Med 22:61-73, Klingensmith WC, Briggs DE, Smith WI: Technetium-99m-MAG3 renal studies: Normal range and reproducibility of physiologic parameters as a function of age and sex. J Nucl Med 35: , Taylor A: Radionuclide renography: A personal approach. Sem Nucl Med 29: , Stabin M, Taylor A, Eshima D, et al: Radiation dosimetry for technetium-99m-mag3, technetium-99m-dtpa, and iodine-131-oih based on human biodistribution studies. J Nucl Med 33:33-40,

6 11. Taylor A, Thakore K, Folks R, et al: Background subtraction in technetium-99m-mag3 renography. J Nucl Med 38:74-79, Dubovsky EV, Russell CD Bischof-Delaloye A, et al: Report of the radionuclides in nephrourology committee for evaluation of transplanted kidney (Review of techniques). Sem Nucl Med 29: , O'Reilly P Aurell M, Britton K, et al: Consensus on diuresis renography for investigating the dilated upper urinary tract. J Nucl Med 37: , Mandell GA, Cooper JA, Leonard JC, et al: Procedure guideline for diuretic renography in children. J Nucl Med 38: , Gordon I, Dhillon HK, Gatanash H, et al: Antenatal diagnosis of pelvic hydronephrosis: Assessment of renal function and drainage as a guide to management. J Nucl Med 32: , Klingensmith WC, Tyler HN, Marsh WC, et al: Effect of hydration and dehydration on technetium-99m CO2DADS renal studies in normal volunteers. J Nucl Med 26: , Wong DC, Rossleigh MA, Farnsworth RH: F+0 diuresis renography in infants and children. J Nucl Med 40: , Choong KKL, Gruenewald SM, Hodson EM, et al: Volume expanded diuretic renography in the postnatal assessment of suspected uretero-pelvic junction obstruction. J Nucl Med 33: , Rossleigh MA, Leighton DM, Farnsworth FH: Diuresis renography: The need for an additional view after gravity-assisted drainage. Clin Nucl Med 18: , Tribble KA, Wilkinson RH, Beytas EM: Spontaneous urinary extravasation during a diuretic radionuclide renal study: Report of two cases. Clin Nucl Med 15: , Fommei E, Ghione S, Hilson AJW, et al: Captopril radionuclide test in renovascular hypertension: A European multicentre study. Eur J Nucl Med 20: , Claveau-Tremblay R, Turopin s, De Braikeleer M, et al: False-positive Captopril renography in patients taking calcium antagonists. J Nucl Med 39: , Taylor A, Nally J, Aurell M, et al: Consensus report on ACE inhibitor renography for detecting renovascular hypertension. J Nucl Med 37: , Chen CC, Hoffer PB, Vahjen G, et al: Patients at high risk for renal artery stenosis: A simple method of renal scintigraphic analysis with Tc-99m DTPA and captopril. Radiology 176: , Dey HM, Hoffer PB, Lerner E, et al: Quantitative analysis of the technetium-99m-dtpa captopril renogram: Contribution of washout parameters to the diagnosis of renal artery stenosis. J Nucl Med 34: , Tahlor at, Fletcher JW, Nally JV, et al: Procedure guideline for diagnosis of renovascular hypertension. J Nucl Med 39: , Taylor A, Manatunga A, Morton K, et al: Multicenter trial validation of a camera-based method to measure Tc-99m mercatoacetyltriglycine, or tc-99m MAG3, clearance. Radiology 204:47-54, Prigent A, Cosgriff P, Gates GF, et al: Consensus report on quality control of quantitative measurements of renal function obtained from the renogram: International consensus committee from the scientific committee of radionuclides in nephrourology. Sem Nucl Med 29: , Gates GF: A dose-attenuation shield for use in glomerular filtration rate computations: A method for combined renal scintiangiography and functional quantification. Clin Nucl Med 16:73-78, Taylor A, Lewis C, Giacometti A, et al: Improved formulas for the estimation of renal depth in adults. J Nucl Med 34: , Taylor A: Fomulas to estimate renal depth in adults. J Nucl Med 35: , Maneval DC, Magill HL, Cypess AM, et al: Measurement of skin-to-kidney distance in children: Implications for quantitative renography. J Nucl Med 31: , Russell CD, Taylor A, Eshima D: Estimation of technetium-99m-mag3 plasma clearance in adults from one or two blood samples. J Nucl Med 30: , Kengen RA, Meijer S, Beekhuis H, et al: Technetium-99m-MAG3 clearance as a parameter of effective renal plasma flow in patients with proteinuria and lowered serum albumin levels. J Nucl Med 32: , Gordon I, Anderson PJ, Orton M, et al: Estimation of technetium-99m-mag3 renal clearance in children: Two gamma camera techniques compared with multiple plasma samples. J Nucl Med 32: , Tc-99m: In MIRD: Radionuclide Data and Decay Schemes, DA Weber, KF Eckerman, AT Dillman, JC Ryman, eds, Society of Nuclear Medicine, New York, 1989, pp Normal Finding > Klingensmith WC, Briggs DE, Smith WI: Technetium-99m-MAG3 renal studies: Normal range and reproducibility of physiologic parameters as a function of age and sex. J Nucl Med 35: , > Rossleigh MA, Thomas MY, Moase AL: Determination of the normal range of furosemide half-clearance times when using Tc-99m MAG3. Clin Nucl Med 19: , > Klingensmith WC, Lammertse DP, Briggs DE, et al: Technetium-99m-MAG3 renal studies in spinal cord injury patients: Normal range, reproducibility, and change as a function of duration and level of injury. Spinal Cord 34: ,

7 > Russell CD, Li Y, Kahraman NH, et al: Renal clearance of technetium-99m-mag3: Normal values. J Nucl Med 36: , > Meyer G, Piepsz A, Kolinska J, et al: Technetium-99m-mercaptoacetyltriglycine clearance values in children with minimal renal disease: Can a normal range be determined? Eur J Nucl Med 25: , > Wong JCH, Rossleigh MA, Farnsworth RH: Utility of technetium-99m-mag3 diuretic renography in the neonatal period. J Nucl Med 36: , > Lythroe MF, Gordon I, Anderson PJ: Effect of renal maturation on the clearance of technetium-99m mercaptoacetyltriglycine. Eur J Nucl Med 21: , > Itoh K, Nonomura K, Yamashita T, et al: Quantification of renal function with a count-based gamma camera method using technetium-99m-mag3 in children. J Nucl Med 37:71-75, > Schofer O, Konig G, Bartels U, et al: Technetium-99m mercaptoacetyltriglycine clearance: Reference values for infants and children. 22: ,