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PubMed1983

A study of cold cardioplegic myocardial protection in rats: an experimental model using the uptake of technetium 99m pyrophosphate and enzyme activity as parameters of injury.

This study compares the use of St Thomas' cardioplegia and cold saline cardioplegia at 4 degrees C for protection against global myocardial ischaemia in a model of heterotopic cardiac transplantation in rats of isogeneic strain. The parameters of myocardial injury applied were the uptake of Technetium 99m pyrophosphate (Tc 99m Pyp) in the transplanted heart and the measurement of serum total creatine kinase (CK) and creatine kinase MB (CK:MB) isoenzyme activity. The findings indicate that St Thomas' cardioplegic solution confers improved myocardial protection compared with normal saline as judged by statistically significant differences between: (a) the uptake of Tc 99m Pyp between the two solutions at 30 min storage: and (b) the peak total serum creatine kinase enzyme activity at 90 min storage. Excellent correlation was present between the uptake of Tc 99m Pyp and peak total serum creatine kinase activity. Further application of this model is described.

Animals↗
PubMed1984

Assessment of myocardial necrosis immediately after intracoronary thrombolysis by intracoronary injection of technetium-99m pyrophosphate.

To assess myocardial necrosis immediately after intracoronary thrombolysis, thallium-201 (TL-201) and technetium-99m pyrophosphate (Tc-99m PYP) were injected simultaneously into the coronary artery in 25 patients with acute transmural myocardial infarction. In 17 of the 25 patients, the occluded coronary artery was reopened. Minutes after the intracoronary injection of Tc-99m PYP into the reopened coronary artery a localized accumulation was seen within the area of the Tl-201 defect in all patients. Control intravenous scintigraphy, which was performed in 8 of these 17 patients 1-6 days later, and in 2 patients 18 and 42 days after infarction, revealed a Tc-99m PYP spot similar to that of the acute intracoronary Tc-99m PYP scintigram in all 10 patients. In the 8 of the 25 patients, in whom intracoronary thrombolysis failed, no localized Tc-99m PYP accumulation was seen after injection into the infarct vessel. In 5 of these patients, a control intravenous scintigram, performed 1-8 days later, resulted in a Tc-99m PYP spot in the area of the Tl-201 defect. We conclude that, in the presence of therapeutic or spontaneous reperfusion, Tc-99m PYP scintigraphy may provide a useful method of assessing myocardial necrosis during the early stage of an acute myocardial infarction.

Adult↗
PubMed1987

Technetium pyrophosphate muscle scans in inflammatory muscle disease.

Technetium-99M pyrophosphate (TcPYP) nuclear scans of extremities were performed on 15 patients at 10 minutes and 2 hours after isotope injection. Scans were carried out both to confirm the diagnosis of myositis and to direct subsequent muscle biopsy. Five of six patients with clinical features strongly suggestive of inflammatory muscle disease had positive scans. All muscle biopsies performed at areas of increased isotope uptake showed inflammatory muscle disease. All nine patients not suspected of active inflammatory muscle disease had negative scans. Two of these underwent muscle biopsy with negative results. Our observations suggest that TcPYP muscle scans may be useful both to confirm the clinical suspicion of inflammatory muscle disease and in directing the choice of site for muscle biopsy.

Biopsy↗
PubMed1989

Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: significance of intraoperative myocardial ischemia and hemodynamic control.

The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic, preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMed2000

Sentinel node biopsy in melanoma using technetium-99m rhenium colloid: the London experience.

Nodal metastases in patients with melanoma identify a reduction of survival by 50%; however, elective lymph node dissection (ELND) has not been shown clearly to improve survival. Morton's technique of sentinel node biopsy, using preoperative lymphoscintigraphy and intraoperative blue dye, addresses elegantly the controversy regarding ELND. Sentinel node biopsy has been shown to stage the patient accurately because metastases from melanoma follow an orderly progression from the sentinel node to the remainder of the basin. Fifty-six consecutive patients with American Joint Committee on Cancer stage 1b or 2 melanoma seen at the London Health Sciences Center between July 1998 and January 2000 were enrolled prospectively to undergo sentinel node biopsy. Preoperative lymphoscintigraphy was conducted in the nuclear medicine department. A total of 10 to 15 MBq (0.27-0.41 mCi) of technetium 99m (99mTc) rhenium colloid or filtered sulfur colloid was injected intradermally around the biopsy scar. Images were obtained to localize all draining nodal basins. The location of the sentinel node was marked on the skin. The patient was taken to the operating room and anesthetized. Isosulfan blue dye was injected intradermally around the biopsy scar. A hand-held gamma probe was used intraoperatively as a guide to the first draining node. Blue-stained lymphatic channels aided in the dissection. Sentinel node localization was successful in 55 of 56 patients, for an overall success rate of 98%. Preoperative lymphoscintigraphy identified a sentinel node in an unpredictable location in 32% of patients. On average, 2.3 sentinel nodes per patient were identified on the initial scan, and 2.2 sentinel nodes per patient were recovered at surgery. Both 99mTc rhenium and filtered sulfur colloid showed no substantial differences in tracer uptake and retention in the sentinel node. Twelve patients had a positive sentinel node on routine histology, and 11 patients subsequently underwent completion lymphadenectomy. The mean thickness of the primary melanoma in the 12 patients with positive sentinel nodes was 3.7 mm compared with a mean tumor thickness of 1.8 mm in the remaining 41 patients with negative biopsies (p = 0.0003). Two patients experienced recurrence in a regional basin after negative pathological evaluation of the sentinel node. Reverse transcription-polymerase chain reaction analysis of both of these patients was positive. Two patients are alive with metastatic disease and 54 patients are alive without disease, with a mean follow-up of 1 year (range, 2-24 months). Complications occurred at a substantially higher rate (45%) after completion lymphadenectomy than after sentinel node biopsy alone (9%). Sentinel node biopsy is a feasible technique with a high success rate (98%), but it requires a multidisciplinary approach. This study validates the clinical usefulness of 99mTc rhenium colloid for lymphoscintigraphy.

Adult↗
PubMed1985

False-positive technetium-99m DMSA renal imaging in two cases of malrotated kidney.

Technetium-99m dimercaptosuccinic acid (Tc-99m DMSA) has been used as a renal imaging agent of choice. A few false-positive cases of Tc-99m DMSA imaging have been reported. The authors have experienced false-positive Tc-99m DMSA imagings in two cases of a malrotated kidney, and this finding previously has not been reported in the literature. The possibility of its nuclear imaging diagnosis with Tc-99m DTPA is also discussed.

Adult↗
PubMed1985

Technetium-99m glucoheptonate as a scanning agent in hepatocellular carcinoma.

Technetium-99m glucoheptonate (Tc-99m GH) is concentrated in pulmonary and cerebral tumors. The purpose of this study was to assess the uptake of this radionuclide by hepatocellular carcinoma. Its concentration by the primary tumor was compared with that in the non-neoplastic hepatic tissue in 31 patients who showed obvious defects on a colloid scan, and its uptake by pulmonary metastases was examined in six patients with x-ray evidence of this complication. In two patients, the uptake by the tumor was greater than, in six it was equal to, and in ten it was less than that in the non-neoplastic hepatic tissue. In the remaining 13 patients, there was no concentration at all in the tumor. In none of the six patients with multiple pulmonary metastases could uptake of Tc-99m GH by the metastases be demonstrated. It is concluded that Tc-99m GH is of limited value in the diagnosis of primary or metastatic hepatocellular carcinoma.

Adult↗
PubMed1989

Myocardial perfusion imaging with a new radiotracer, technetium-99m-hexamibi (methoxy isobutyl isonitrile): comparison with thallium-201 imaging.

Technetium-99m-hexamibi (methoxy isobutyl isonitrile) is a Tc-99m-hexakis analog that can be used as a myocardial perfusion imaging agent. This is a report of an initial study that was performed in four institutions to assess the feasibility of Tc-99m-hexamibi myocardial imaging for the detection of coronary artery disease in patients undergoing treadmill stress test. Thirty-three patients referred for evaluation of chest pain had two exercise stress tests, one with Tl-201 and at least 24 hours after, and a second one with Tc-99m-hexamibi. Myocardial planar imaging started 60 minutes after injection at stress of 10-20 mCi of Tc-99m-hexamibi. Because this agent does not redistribute in myocardium after a stress injection, a second injection of 10-20 mCi of Tc-99m-hexamibi was performed with the patient at rest a few days later. Qualitative assessment of both Tl-201 and Tc-99m-hexamibi myocardial distribution was performed in 297 left ventricle segments (three segments of each of three views). There was a good correlation for the presence of normality, scar, or ischemia with the two radiopharmaceuticals, both on a segment by segment (259/297, or 87.2%) and patient-by-patient basis (29/33, or 87.9%). The number of segments found ischemic with Tl-201 and with Tc-99m-hexamibi were nearly equal, as were the number that were normal with one radiopharmaceutical and ischemic by the other. This initial study demonstrates that it is possible to detect stress-induced abnormalities of myocardial perfusion with Tc-99m-hexamibi similar to Tl-201 imaging.

Adult↗
PubMed1999

Utility of technetium-99m-labeled-galactosyl human serum albumin scintigraphy for estimating the hepatic functional reserve.

Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (Tc-GSA) is a receptor binding agent, specific for asialoglycoprotein receptor, that resides exclusively on the plasma membrane of mammalian hepatocytes. The usefulness of Tc-GSA for estimating the hepatic functional reserve was retrospectively evaluated in patients undergoing a hepatic resection. Tc-GSA scintigraphy was performed in 35 patients before hepatectomy, and the hepatic uptake ratio (LHL15) was calculated. The LHL15 was then compared with the findings of conventional liver function tests, the indocyanine green retention rate in 15 minutes (ICG R15), and histologic activity index (HAI) score. Significant correlations were observed between the LHL15 and values of ICG R15, prothrombin time activity, serum levels of total bilirubin, hyaluronic acid, and values of HAI score. Ratios of LHL15 to preoperative liver volume (LHL-V) correlated well with the regenerative rates of the residual liver after major hepatectomy. In addition, patients with more than 0.76 of LHL-V value had no complications in postoperative course, whereas those with less than 0.73 had several complications due to hepatic dysfunction. Tc-GSA scintigraphy thus appears to be a useful diagnostic tool for evaluating functioning mass of the liver and the values of LHL-V seems to be able to demonstrate regenerative activity in the residual liver after hepatectomy.

Adult↗
PubMedDate not supplied

Hepatobiliary scintigraphy with technetium-99m disofenin in the evaluation of neonatal cholestasis.

To assess the reliability of technetium-99m disofenin scanning in evaluating neonatal cholestasis, 33 neonates (less than 3 months of age) with direct hyperbilirubinemia were evaluated prospectively by cholescintigraphy. Results of this test were compared to those of standard serum tests of liver function, ultrasonography, and liver biopsy. The diagnosis of biliary atresia was suggested by a serum gamma-glutamyl transpeptidase (gamma-GTP) greater than 300 units/L, absence of the gallbladder on ultrasonography, and a lack of detectable radioisotope in the gastrointestinal and/or extrahepatic biliary tract on cholescintigraphy. Each of these tests lacked sensitivity and/or specificity when compared to liver biopsy. Of the nine neonates with biliary atresia, three had gallbladders identified by ultrasonography and two had gamma-GTP less than 300 units/L. Of the 24 neonates without biliary atresia, eight had cholescintigraphy without detectable radioisotope excretion, four had ultrasonography that failed to visualize the gallbladder, and nine had gamma-GTP greater than 300 units/L. Cholescintigraphy excluded the diagnosis of biliary atresia when gut and/or extrahepatic biliary excretion of isotope was seen. However, cholescintigraphy required more time, 6-8 days, and was less specific than ultrasonography and liver biopsy. We recommend that cholescintigraphy should not be routinely used in evaluating neonatal cholestasis, especially if it delays surgical intervention.

Biliary Atresia↗
PubMed1988

Detection of diaphragmatic disruptions by peritoneoscintigraphy using technetium-99M diethylene-triamine pentacetic acid.

Intraperitoneal injection of a selected radiopharmaceutical results in the diffusion of radioactive material throughout the peritoneum. A diaphragmatic injury should theoretically result in the diffusion of the radioactive material into the chest. To test this hypothesis, Technetium-99m diethylene-triamine pentacetic acid (Tc-99m DTPA) was administered intraperitoneally by either direct needle injection or catheter into 18 rabbits. Four of the rabbits served as controls and did not have any diaphragmatic injury. Fourteen rabbits had surgically induced diaphragmatic tears of varying size (1/4 to 1 cm) after thoracotomy. Four of the 14 rabbits were dropped from the study because they had inadequate peritoneal injections of the radiopharmaceutical. The remaining ten rabbits showed peritoneoscintigraphic evidence of diaphragmatic injury either by showing passage of the radiotracer into the chest, demonstrating the site of injury as a focal region of increased radiotracer uptake, or showing both of these features. Peritoneoscintigraphy appears to be a potentially useful modality in the detection of diaphragmatic injury.

Animals↗
PubMed1985

Clinical evaluation of a technetium-99m bone imaging agent based on the vicinal diphosphonate 1,2-diphosphonoethyleneglycol (DPEG).

From a series of technetium-99m labelled agents based on a vicinal diphosphonic acid structure, the ligand 1,2-diphosphonoethyleneglycol (DPEG) was selected for clinical study on the basis of a biodistribution in rats which compared well with that of methylene disphonphonate (MDP). The 99Tcm-DPEG agent was assessed in ten patients in whom bone metastases had been demonstrated by 99Tcm-MDP imaging two to seven days previously. Visual comparison of the skeletal images obtained with the two agents revealed the same number of bone metastases at the same locations. Statistical analysis of the data revealed no significant differences between the two radiopharmaceuticals on the basis of lesion to soft tissue ratio and lesion to normal bone ratio, although a slightly higher lesion to soft tissue ratio was found for MDP than for DPEG (p less than 0.03). At least for the formulation tested, it is concluded that this new radiopharmaceutical based on the P-C-C-P structure does not possess diagnostic advantages over 99Tcm-MDP for the detection of bone metastases.

Aged↗
PubMed1983

Efficacy of technetium Tc 99m pyrophosphate imaging in patients with equivocal myocardial infarction.

We studied the efficacy of technetium Tc 99m pyrophosphate imaging in patients with equivocal evidence of acute myocardial infarction. Only patients with positive enzyme findings (regardless of ECG findings) had scans with greater than or equal to 2+ focal uptake. None of 26 patients with negative or equivocal enzyme findings (regardless of ECG findings) had greater than 2+ diffuse uptake. These results support the contention that infarct-avid imaging has little clinical utility in patients with equivocal evidence of myocardial infarction.

Clinical Enzyme Tests↗
PubMed1988

Renal scintigraphy with technetium Tc 99m succimer: clinical utility in newborns with cystic renal dysplasia.

We have presented the case of a neonate with bilateral cystic renal dysplasia and normal pulmonary development, in whom technetium Tc 99m succimer scintigraphy demonstrated absence of normal renal cortical tubular tissue and correctly predicted that life-sustaining renal function would not occur. Since renal uptake of this radioactive agent depends on the functional mass of cortical tubular tissue, and the cystic dysplasias are characterized by abnormal dysplastic renal ductal and tubular tissue, this imaging agent can provide important prognostic information concerning renal function in these patients.

Humans↗
PubMed2006

Detection of endoleaks after endovascular aneurysm repair with use of technetium-99m sulfur colloid and (99m)Tc-labeled red blood cell scans.

PURPOSE: This study was performed to determine whether endoleaks could be detected after endovascular aneurysm repair (EVAR) with use of technetium-99m sulfur colloid and (99m)Tc-labeled red blood cell (RBC) nuclear medicine scans. MATERIALS AND METHODS: There were 13 patients enrolled in this study: nine with endoleaks seen on computed tomographic (CT) angiography and four with no endoleak on CT angiography. All patients underwent regularly scheduled surveillance CT angiography examination after EVAR to evaluate for endoleak. Endoleak detection was then attempted in each patient with two nuclear medicine scans: a (99m)Tc sulfur colloid scan and a (99m)Tc-labeled RBC scan. Flow images (5 seconds per frame) were obtained for 1 minute after intravenous administration of 555 MBq (15 mCi) (99m)Tc sulfur colloid. Sequential dynamic images were then obtained every minute for 30 minutes. Next, a (99m)Tc-labeled RBC study was performed after the intravenous administration of 370-1,073 MBq (10-29 mCi) in vitro labeled (99m)Tc RBCs. Flow images were obtained, followed by sequential dynamic images obtained every minute for 30 minutes. Single photon emission CT images of the abdomen were then acquired. The nuclear medicine scans were evaluated for the presence or absence of endoleak independent of the CT angiography findings. RESULTS: Of the nine patients with endoleaks on CT angiography, seven (78%) had them detected by nuclear medicine examinations. Two of the nine endoleaks seen on CT angiography (22%) were not seen on either scintigraphic examination. All patients with no endoleak on CT angiography had their nuclear medicine scans correctly interpreted as showing no endoleak present (n = 4; 100%). No complications occurred as a result of the nuclear medicine scans. CONCLUSIONS: Endoleaks can be detected with (99m)Tc sulfur colloid and (99m)Tc-labeled RBC nuclear medicine scans. This initial work suggests that the sensitivities of these scintigraphic scanning methods for endoleak detection are lower than that of CT angiography.

Aortic Aneurysm, Abdominal↗
PubMedDate not supplied

Technetium phosphate bone scan in the diagnosis of septic arthritis in childhood.

The technetium phosphate bone scans of 106 children with suspected septic arthritis were reviewed to determine whether the bone scan can accurately differentiate septic from nonseptic arthropathy. Only 13% of children with proved septic arthritis had correct "blind" scan interpretation. The clinically adjusted interpretation did not identify septic arthritis in 30%. Septic arthritis was incorrectly identified in 32% of children with no evidence of septic arthritis. No statistically significant differences were noted between the scan findings in the septic and nonseptic groups and no scan findings correlated specifically with the presence or absence of joint sepsis.

Adolescent↗
PubMed1980

Skeletal scintigraphy with technetium diphosphonate in multiple myeloma--a comparison with skeletal x-ray.

Twenty-one patients with multiple myeloma were examined in close time relation with skeletal X-ray survey and bone scanning using technetium diphosphonate. Results indicate that X-ray is superior to bone scan in detecting myelomatous bone lesions. Approximately twice as many lesions were detected by X-ray as by bone scan. An exception to this general finding is the lumbar spine and rib cage, in which the two methods are equally reliable. Thus, a negative bone scan does not exclude the possibility of a myelomatous bone lesion.

Bone Neoplasms↗