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PubMed1978

Evaluation of technetium scanning for myocardial contusion.

Myocardial contusion is a serious problem not easily diagnosed. Laboratory and clinical studies carried out on myocardial infarction suggested that Technetium scanning might clarify this diagnostic dilemma. Radionuclide imaging with Technetium was carried out in 29 patients suspected of having myocardial contusion. Of 13 patients in whom contusion was confirmed electrocardiographically, scan was positive in only two. Use of the technique in diagnosis of myocardial contusion is not recommended.

Adolescent↗

PubMed2003

Preoperative parathyroid localization: correlating false-negative technetium 99m sestamibi scans with parathyroid disease.

OBJECTIVE/HYPOTHESIS: The recent trend toward minimally invasive directed parathyroid surgery has increased the surgeon's reliance on preoperative parathyroid localization. Technetium Tc 99m sestamibi scanning is generally viewed as the gold standard for preoperative localization, with reported sensitivities of 75% to 100% and specificities of 75% to 90%. However, in each reported series there exists a group of patients in whom preoperative localization is either equivocal or negative. STUDY DESIGN: We focused on a subset of patients from our parathyroid database with false-negative sestamibi (MIBI) scans, in an attempt to elucidate features that could affect these studies. We identified 20 patients with negative preoperative scans and confirmed parathyroid disease. We compared them with 22 consecutive patients with positive scans, correlating the following variables: patient age, gender, concomitant thyroid disease (Hashimoto's thyroiditis, papillary thyroid carcinoma, thyroid adenoma), preoperative parathyroid hormone values, location and number of enlarged parathyroid glands, parathyroid weight, and the relative proportion of chief cells, clear cells, oxyphil cells, and adipose tissue. METHODS: Retrospective chart review of clinicopathological and radiological findings. RESULTS: We found that patients with false-negative scans were more likely to have an enlarged parathyroid containing a high proportion of clear cells (P =.01). A trend was seen (P =.1) correlating increased parathyroid fat content and false-negative scans. Conversely, positive preoperative scans were more likely to be associated with a higher percentage of oxyphil cells (P =.02). Univariate analysis for other variables, as well as logistic regression analysis, did not achieve statistical significance. CONCLUSIONS: To date, the present study is the largest clinicopathological review of patients with false-negative sestamibi scans. Technetium Tc 99m uptake correlates with parathyroid oxyphil cell content, and false-negative scans can occur with parathyroid glands containing predominantly clear cells.

False Negative Reactions↗

PubMed1997

Technetium-MIBI as a glioma imaging agent for the assessment of multi-drug resistance.

OBJECTIVE: To explore the presence of MDR-1 drug resistance in human glioma utilizing a Single Photon Emission Computerized Tomography (SPECT) imaging agent, sesta-MIBI, and testing cases interpreted as positive for drug resistance with molecular characterization of subsequent tissue biopsy, including RNA, Northern blot analysis, and polymerase chain reaction, and in situ hybridization. METHODS: Six patients that carried a diagnosis of biopsy-proven glioma underwent dual isotope SPECT imaging with thallium 201 and technetium sesta-MIBI. All six patients underwent subsequent surgical reexcision of their tumors, and tissue was immediately flash frozen for further analysis. PolyA RNA was isolated and subsequently analyzed by both Northern blot analysis and RT-PCR utilizing an MDR-1 probe (ATCC) and MDR-1 primers. RESULTS: Four patients with SPECT concordance yielded tumors without MDR-1 expression whereas two patients with SPECT discordance yielded tumors with MDR-1 gene expression. In one discordant case we subsequently performed RT-PCR in situ amplification/ hybridisation and immunohistochemistry with, respectively, an MDR-1 sense primer with Biotin labeled probes and an MDR-1 monoclonal antibody, and both analyses revealed MDR-1 expression in tumor cells. CONCLUSION: These data support the use of SPECT technetium sesta-MIBI to evaluate the presence of MDR-1 gene expression in gliomas.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Failure of technetium-99m hexamethylpropylene amine oxime leukocyte scintigraphy in the evaluation of children with suspected appendicitis.

To determine the accuracy and reliability of a labeled leukocyte imaging technique in the early diagnosis of pediatric appendicitis, we prospectively studied patients presenting to the pediatric emergency department with abdominal pain suggestive of appendicitis. Patients scheduled for urgent laparotomy were excluded, as were postmenarchal females. Blinded interpretations by two independent radiologists were compared with surgical findings, if managed operatively, or with discharge diagnoses and three week follow-up, if managed medically. Twenty-three children underwent technetium-99m hexamethylpropylene amine oxime (HMPAO) leukocyte scintigraphy. Seven had pathologically proven appendicitis, with false negative interpretations made in three and five cases by the two radiologists. Sixteen patients had prompt resolution of symptoms; however, scintigraphic abnormalities were identified in 10 and seven cases by the two radiologists. Resulting sensitivity, depending on the individual reader, ranged from 29 to 57%, with specificity 38 to 56%, positive predictive value 22 to 29%, negative predictive value 64 to 67%, and accuracy 43 to 48%. Interrater reliability for agreement on the scintigraphic diagnosis of appendicitis was poor (kappa = 0.38). Technetium-99m HMPAO leukocyte scintigraphy was neither accurate nor reliable as a diagnostic tool in a subgroup of pediatric patients with an initial clinical presentation equivocal for appendicitis. This finding contradicts previously published experience using similar scintigraphic techniques.

Abdominal Pain↗

PubMed1975

Single image pericardial effusion evaluation with technetium compounds.

Three cases of suspected pericardial effusion were evaluated with rapid, noninvasive procedure, combined use of macroaggregated albumin technetium 99m and human serum albumin technetium 99m to produce a single radiography showing the heart, liver, and lung perfusion simultaneously. This technic confirmed the diagnosis of pericardial effusion in two cases and ruled out this possibility in the third case.

Adult↗

PubMed1995

Technetium Tc 99m sestamibi scan for localizing abnormal parathyroid glands after previous neck operations: preliminary experience in reoperative cases.

We used technetium Tc 99m sestamibi for successful preoperative localization of abnormal parathyroid glands in nine patients with hyperparathyroidism and a history of neck surgery. The intraoperative and pathological findings were correlated with the preoperative technetium-sestamibi scan results. These nine patients had had 13 previous neck operations, two for thyroid disease, and 11 for hyperparathyroidism. In the two operated on for thyroid disease, the 99mTc-sestamibi scan localized a parathyroid adenoma. In one patient, the three remaining hyperplastic parathyroid glands were localized using 99mTc-sestamibi scan. The other six patients had 10 operations for hyperparathyroidism; the 99mTc-sestamibi scan localized the remaining parathyroid glands causing hypercalcemia. In this preliminary experience, the 99mTc-sestamibi scan localized all the abnormal parathyroid glands causing hyperparathyroidism in patients who had previously had neck surgery.

Adult↗

PubMedDate not supplied

Clinical application of rest thallium-201/Stress technetium-99m sestamibi dual isotope myocardial perfusion single-photon emission computed tomography.

Stress radionuclide myocardial perfusion imaging is a commonly used modality to evaluate patients with known or suspected coronary artery disease. The dual isotope rest thallium-201/stress technetium-99m sestamibi gated single-photon emission computed tomography protocol has gained increasing popularity for these applications. By combining the use of thallium-201, the optimal radioisotope for assessment of viability, with technetium-99m, a radionuclide agent that permits optimal image resolution and simultaneous assessment of viability information, maximization of clinical information can be achieved. Recent publications have demonstrated the efficacy of this imaging approach for both the identification of the presence of coronary artery disease and risk stratification.

Exercise Test↗

PubMed2006

Role of technetium-99m N,N-ethylenedicysteine renal scintigraphy in the evaluation of differential renal function and cortical defects.

PURPOSE: This study was performed to evaluate the effectiveness of technetium-99m N,N-ethylenedicysteine (Tc-99m EC) in comparison to technetium-99m dimercaptosuccinic acid (Tc-99m DMSA) scintigraphy. Differential renal function (DRF) was calculated by both methods and the cortical-phase images of dynamic Tc-99m EC scintigraphy were evaluated for parenchymal defects. MATERIALS AND METHODS: A total of 62 patients with various kidney disorders ranging in age from 1 to 44 years underwent both Tc-99m DMSA and Tc-99m EC scintigraphy. Tc-99m EC summed images of the cortical phase and Tc-99m DMSA images were evaluated visually and quantitatively. Visual analysis was used to define renal parenchymal abnormalities. Quantitative analysis was used in the calculation of DRF. The Tc-99m DMSA scan was taken as the gold standard, and the summed Tc-99m EC scan findings were compared against it. RESULTS: The images obtained with Tc-99m DMSA and Tc-99m EC scintigraphy revealed 99 and 97 focal defects, respectively. The 2 renal parenchyma defects located in the ventral middle sections remained undetected with Tc-99m EC scintigraphy. DRF of the kidneys in each patient was compared using both radiopharmaceuticals. Highly positive correlation between the differential function of these 2 investigations was found (R = 0.91, P = 0.001). The values of mean DRF of the left kidney on Tc-99m EC and Tc-99m DMSA images were 45.8 +/- 19.1 and 45.0 +/- 20.4, respectively. There were no significant differences (P > 0.05). CONCLUSION: This study suggests that although Tc-99m DMSA scintigraphy remains the gold standard method for evaluating parenchymal abnormalities, Tc-99m EC scintigraphy can be a reliable single-modality study to evaluate renal cortical defects, DRF, perfusion, drainage of the urinary system, and indirect evidence of vesicoureteric reflux with the added advantage of low radiation exposure to the patient.

Adolescent↗

PubMed1978

Technetium uptake in the management of thyrotoxicosis.

The thyroid uptake of 99m-technetium after 7 days of triiodothyronine was measured at the end of a course of antithyroid drugs in ninety-seven patients with thyrotoxicosis who were then followed up for at least 1 year. The relapse rate in sixty-six patients in whom the uptake was suppressed to less than 4% was 21% whereas it was 90% in those patients in whom the uptake was more than 4%. A prediction of the outcome on the basis of whether the uptake was more or less than 4% would have been correct in 82% of patients. Serial tests during treatment show that a correct prediction could have been made one year after starting treatment in 86% of cases depending on whether the uptake at that time suppressed to more or less than 6%. The initial unsuppressed 99m-technetium successfully predicted the likelihood of relapse after a course of antithyroid drugs in 75% of patients. We recommend that alternative therapy should be advised in those patients whose uptakes fail to suppress below 6% after 1 year of drug therapy.

Adult↗

PubMed1989

Technetium-99m radiocolloid scintigraphy, planar and SPECT red blood cell imaging and ultrasonography in diagnosis of hepatic hemangioma.

Technetium-99m planar sulfur colloid scintigraphy, red blood cell imaging and ultrasonography were performed in eighteen patients of hepatic hemangioma to evaluate their diagnostic utility. Radiocolloid scans detected fourteen hemangiomas in 12 patients as focal hepatic defects but missed 9 lesions smaller than 2.5 cm in the other 6 patients, accounting for a 61% sensitivity. All 23 lesions were avascular or normovascular on radionuclide flow study. Serial planar red blood cell scintigraphy showed characteristic gradually increasing focal isotopic accumulation in the 14 hemangiomas which had identifiable cold areas on the radiocolloid study. One of 6 patients with normal radiocolloid scan also showed the typical increasing blood pool pattern of hemangioma, five had normal planar scans till 1 1/2 hours. SPECT red blood cell imaging in these 5 patients detected an additional seven hemangiomas. All 7 lesions were smaller than 2.5 cm. One 1.5 cm hemangioma was missed on both planar and SPECT red blood cell imaging. Region of interest ratios in SPECT transaxial images confirmed gradually increasing concentration of labeled red blood cells in the lesions. Ultrasonography detected 22 of the 23 hemangiomas. Ten were hyperechoic, average size 2.25 cm. Twelve were of mixed pattern, generally larger, average size 7.2 cm. Sonography is useful in the detection of hepatic hemangiomas as a focal mass lesion, but the variable sonographic appearance precludes a definite pathological diagnosis. Technetium-99m red blood cell imaging appears a sensitive technique in detection of hepatic hemangioma, with SPECT being especially useful in locating smaller lesions. The addition of useful in locating smaller lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1998

Technetium-99m (V) dimercaptosuccinic acid uptake by choroidal melanoma before and after iodine-125 brachytherapy.

PURPOSE: The value of the new tumour-seeking agent technetium-99m (V) dimercaptosuccinic acid (99mTc (V) DMSA), is assessed by the visualization of choroidal melanoma before and after iodine-125 episcleral plaque brachytherapy. METHODS: A prospective study was conducted on 12 consecutive patients with choroidal melanoma that was to be treated with plaque brachytherapy. The pre-operative mean (+/- SD) maximal tumour basal diameter was 12.9+/-2.9 mm and the mean tumour height was 8.2+/-2.9 mm. Each patient had planar scintigraphy and single-photon emission computed tomography using 99mTc (V) DMSA 2 days before treatment and 8 months following plaque removal. The calculated tumour to background ratios of these two tests were compared. RESULTS: The pre-operative tumour to background ratio was 1.8+/-0.4 and all tumours could be correctly identified. At the time of postoperative imaging, all melanomas showed varying degrees of regression. The mean tumour height was 4.4+/-2.1 mm. The tumour to background ratio was 1.4+/-0.3. The difference between the two scintigraphic results was statistically significant (P = 0.002). CONCLUSIONS: Technetium-99m (V) DMSA scintigraphy can accurately detect choroidal melanoma and document tumour response following episcleral radioactive plaque therapy. As such, this test can be an alternative ancillary investigative tool in the rare event of opaque media or diagnostic uncertainty.

Brachytherapy↗

PubMed1987

Thallium-201-technetium-99m subtraction scanning: its value in 50 cases of hyperparathyroidism submitted to surgery.

Parathyroid surgery was performed on 50 patients following thallium-technetium subtraction scanning. Parathyroid adenomata were correctly localized in 34 (83%). Of eight patients with hyperplastic glands, 15 (75%) of these glands were correctly localized. There were seven (17%) false negative scans and one (2%) false positive result. Thallium-technetium subtraction scanning is a valuable technique in the pre-operative assessment of patients with clinical evidence of hyperparathyroidism.

Adenoma↗

PubMed1984

Multiple sclerosis: periphlebitis retinalis et cerebro-spinalis. A correlation between periphlebitis retinalis and abnormal technetium brain scintigraphy.

Periphlebitis retinae (PR) in multiple sclerosis (MS) is seen as transitory infiltrations around veins in the otherwise normal retina. Cellular infiltrations have been found around veins in the central nervous system (CNS), where it has been suggested that they are the first event in plaque formation. Technetium brain scans are usually normal in MS patients, but transitory abnormal scans of the cerebrum have been found in MS patients during acute attack or exacerbation. In order to test the hypothesis that active PR is a sign of simultaneous disease activity in the CNS, 29 technetium brain scans were carried out on 14 MS patients with active PR and on 15 MS patients without any signs of PR. Significantly more of the patients with active PR, compared with MS patients with previous PR, displayed abnormal brain scans. This indicates that a disruption of the blood brain barrier (BBB) and active PR occur simultaneously in MS.

Adolescent↗

PubMed1999

Reduction of technetium by Desulfovibrio desulfuricans: biocatalyst characterization and use in a flowthrough bioreactor.

Resting cells of Desulfovibrio desulfuricans coupled the oxidation of a range of electron donors to Tc(VII) reduction. The reduced technetium was precipitated as an insoluble low-valence oxide. The optimum electron donor for the biotransformation was hydrogen, although rapid rates of reduction were also supported when formate or pyruvate was supplied to the cells. Technetium reduction was less efficient when the growth substrates lactate and ethanol were supplied as electron donors, while glycerol, succinate, acetate, and methanol supported negligible reduction. Enzyme activity was stable for several weeks and was insensitive to oxygen. Transmission electron microscopy showed that the radionuclide was precipitated at the periphery of the cell. Cells poisoned with Cu(II), which is selective for periplasmic but not cytoplasmic hydrogenases, were unable to reduce Tc(VII), a result consistent with the involvement of a periplasmic hydrogenase in Tc(VII) reduction. Resting cells, immobilized in a flowthrough membrane bioreactor and supplied with Tc(VII)-supplemented solution, accumulated substantial quantities of the radionuclide when formate was supplied as the electron donor, indicating the potential of this organism as a biocatalyst to treat Tc-contaminated wastewaters.

Biodegradation, Environmental↗

PubMed2000

Direct and Fe(II)-mediated reduction of technetium by Fe(III)-reducing bacteria.

The dissimilatory Fe(III)-reducing bacterium Geobacter sulfurreducens reduced and precipitated Tc(VII) by two mechanisms. Washed cell suspensions coupled the oxidation of hydrogen to enzymatic reduction of Tc(VII) to Tc(IV), leading to the precipitation of TcO(2) at the periphery of the cell. An indirect, Fe(II)-mediated mechanism was also identified. Acetate, although not utilized efficiently as an electron donor for direct cell-mediated reduction of technetium, supported the reduction of Fe(III), and the Fe(II) formed was able to transfer electrons abiotically to Tc(VII). Tc(VII) reduction was comparatively inefficient via this indirect mechanism when soluble Fe(III) citrate was supplied to the cultures but was enhanced in the presence of solid Fe(III) oxide. The rate of Tc(VII) reduction was optimal, however, when Fe(III) oxide reduction was stimulated by the addition of the humic analog and electron shuttle anthaquinone-2,6-disulfonate, leading to the rapid formation of the Fe(II)-bearing mineral magnetite. Under these conditions, Tc(VII) was reduced and precipitated abiotically on the nanocrystals of biogenic magnetite as TcO(2) and was removed from solution to concentrations below the limit of detection by scintillation counting. Cultures of Fe(III)-reducing bacteria enriched from radionuclide-contaminated sediment using Fe(III) oxide as an electron acceptor in the presence of 25 microM Tc(VII) contained a single Geobacter sp. detected by 16S ribosomal DNA analysis and were also able to reduce and precipitate the radionuclide via biogenic magnetite. Fe(III) reduction was stimulated in aquifer material, resulting in the formation of Fe(II)-containing minerals that were able to reduce and precipitate Tc(VII). These results suggest that Fe(III)-reducing bacteria may play an important role in immobilizing technetium in sediments via direct and indirect mechanisms.

Culture Media↗

PubMed1984

Osteomyelitis and infarction in sickle cell hemoglobinopathies: differentiation by combined technetium and gallium scintigraphy.

Clinical records and scintigrams were reviewed of 18 patients with sickle cell hemoglobinopathies who had undergone combined technetium and gallium scintigraphy during 22 separate episodes of suspected osseous infection. The combined scintigrams were correctly interpreted as indicating osteomyelitis in four studies. Ga-67 localization was abnormally increased in all of these studies, including one where the Tc-99m MDP bone scan showed decreased activity, another where the bone scan was normal at the site of Ga-67 uptake, and two where the distribution of Tc-99m MDP and Ga-67 were incongruent. Of 18 studies in patients with infarction, the combined scintigrams were correctly interpreted in 16 and showed either no local accumulation of Ga-67 or less accumulation than that of Tc-99m MDP at symptomatic sites. In the other two studies, the scintigrams were falsely interpreted as indicating osteomyelitis and showed congruent, increased accumulation of both Tc-99m MDP and Ga-67 (with the latter of similar or greater intensity). This pattern must be considered indeterminate. Overall, the results indicate that the combination of technetium and gallium scintigraphy is an effective means to distinguish osteomyelitis from infarction in patients with sickle cell hemoglobinopathies.

Adolescent↗

PubMed2006

A tracer dose of technetium-99m-labeled liposomes can estimate the effect of hyperthermia on intratumoral doxil extravasation.

PURPOSE: A noninvasive method to monitor intratumoral Doxil delivery in individual patients during targeted tumor therapy is important to predict treatment response. The purpose of this study was to determine if a small tracer dose of technetium-99m (99mTc)-labeled liposomes could be used to quantify the effect of local hyperthermia on intratumoral Doxil extravasation. EXPERIMENTAL DESIGN: Experiments were carried out in a rat fibrosarcoma model with transplanted thigh tumors. Liposomes of approximately same size and composition as Doxil were radiolabeled using [technetium-99m (99mTc)]exametazime. Eight treatment groups received either Doxil, a tracer dose or a large dose of 99mTc-labeled liposomes, or a combination of tracer and Doxil, with or without hyperthermia. This design was chosen to assure that coadministration of both liposomal formulations did not influence their intratumoral distribution. Hyperthermia was done for 45 minutes. Scintigraphic images were obtained at 5 and 18 hours. At 18 hours, tumors were removed and gamma counts as well as doxorubicin concentrations were measured. RESULTS: Intratumoral extravasation of the 99mTc-labeled tracer could be imaged scintigraphically under normothermic and hyperthermic conditions. The thermal enhancement ratio was slightly higher for radiolabeled liposomes than for doxorubicin concentration. However, there was a significant positive correlation of intratumoral doxorubicin concentration and intratumoral uptake of the radiolabeled tracer (expressed as percentage of the injected dose per gram of tissue). Coadministration of radiolabeled liposomes did not negatively influence the amount of drug delivered with Doxil. CONCLUSIONS: The use of a radiolabeled tracer has potential value to monitor drug delivery and estimate the effect of an intervention aimed to increase liposomal accumulation, such as local hyperthermia.

Animals↗

PubMedDate not supplied

Detection of cardiac calcinosis in hemodialysis patients by whole-body scintigraphy with 99m-technetium methylene diphosphonate.

A noninvasive method for the diagnosis of cardiac calcinosis, a life-threatening complication in hemodialysis patients with end-stage renal disease (ESRD), has not, as yet, been firmly established. We tested whether whole body scanning with 99m-technetium methylene diphosphonate (MDP) might visualize cardiac calcinosis. In 19 consecutive chronic hemodialysis ESRD patients (13 males and 6 females, aged 40-81, mean 63 +/- 8 years) with cardiovascular disease [mitral annular calcinosis and/or calcified aortic valve (n = 4), hemodialysis cardiomyopathy (n = 1), coronary artery disease (n = 9) and peripheral artery atherosclerotic disease (n = 6)], MDP uptake in the heart was compared to that in 7 non-ESRD controls with hyperparathyroidism due to adenoma. Cardiac and lung field MDP uptake was confirmed in only 3 (16%) and 5 (26%) of the 19 ESRD subjects, respectively, but was absent in controls. Positive cardiac uptake was related to cardiac calcified complications (mobile intracardiac calcinosis, myocardial calcinosis and mitral annular calcification) and the duration of hemodialysis (p = 0.015). While it was statistically insignificant, subjects showing MDP uptake were elder and had higher serum Ca or Ca x P product and lower intact parathyroid hormone levels. These results suggest that cardiac calcinosis in ESRD patients can be detected noninvasively by myocardial scintigraphy with 99m-technetium MDP.

Adult↗