Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TECHNETIUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources
PubMed1996

Measurement of the secretion of technetium-99m hexamethylpropylene amine oxime into breast milk.

There are no published data for the activity of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) found in breast milk. The amount of radioactivity in breast milk following the administration of 500 MBq 99mTc-HMPAO for a brain perfusion study has been measured. The effective dose to the infant was calculated to be 0.26 mSv, so necessitating no interruption of breast feeding. Unbound 99mTc is readily secreted into breast milk and the effective dose will remain less than 1 mSv if the 99mTc-HMPAO labelling efficiency is >/=99% for the worse reported case, and could remain <1 mSv for the mean reported case for 99mTc-HMPAO labelling efficiencies down to 94%.

Brain↗
PubMed1997

Adenosine technetium-99m sestamibi single-photon emission tomography for the assessment of jeopardized myocardium early after acute myocardial infarction. Paradoxical scintigraphic underestimation of jeopardized myocardium in patients with a severe infarct-related stenosis.

This study investigated the value of technetium-99m sestamibi scintigraphy in identifying patients at risk for post-infarct ischaemia (=jeopardized myocardium), especially within the reperfused infarct region. In 51 patients with a recent (<1 month) myocardial infarction, adenosine 99mTc-sestamibi single-photon emission tomography (SPET) and dobutamine stress echocardiography (DSE) were performed and correlated with the presence of significant coronary artery stenosis [% diameter stenosis (DS) >50%] on quantitative coronary angiography. Regional perfusion activity was analysed semi-quantitatively (score 0-4) on a 13-segment left ventricular model. DSE was used for the estimation of the infarct size (low-dose DSE) and for concomitant evaluation of ischaemia (high-dose DSE). A reversible perfusion defect within the infarct region was observed in 20 of the 37 patients with a significant infarct-related lesion (sensitivity of 54%) and only in one patient without a significant infarct-related lesion (specificity of 93%). Further analysis revealed that the scintigraphic assessment of jeopardized myocardium was fairly good in patients with a moderate (DS 51%-64%) infarct-related stenosis but was inadequate in patients with a severe (DS>/=65%) infarct-related stenosis (sensitivity of 80% vs 36%, P<0.01), while the echocardiographic detection of ischaemia was not influenced by stenosis severity (sensitivity of 73% in both subgroups). This scintigraphic underestimation of jeopardized myocardium was mainly related to a severely impaired myocardial perfusion under baseline conditions, as was evidenced by a significantly more severe rest perfusion score in the infarct region in patients with a severe stenosis as compared to those with a moderate stenosis (average score: 1.5+/-0.7 vs 2.1+/-0.6, P<0.01), while infarct size on echocardiography was similar for both subgroups. It may be concluded that early after an acute myocardial infarction, adenosine 99mTc-sestamibi SPET may underestimate reperfused but still jeopardized myocardium, particularly in patients with a severe infarct-related stenosis. In these patients the evaluation of the ischaemic burden on rest-stress scintigraphy is hampered by the presence of a severely impaired myocardial perfusion in resting conditions.

Adenosine↗
PubMed1997

Comparison of fluorine-18 fluorodeoxyglucose positron emission tomography and technetium-99m methoxyisobutylisonitrile scintimammography in the detection of breast tumours.

The aim of this study was to compare, in breast cancer patients, the diagnostic accuracy of positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) and scintimammography (SMM) using technetium-99m methoxyisobutylisonitrile (MIBI). A total of 20 patients (40 breasts with 22 lesions) were evaluated serially with MIBI and, on the following day, with FDG. For SMM, planar and single-photon emission tomography imaging in the prone position was performed starting at 10 min following the injection of MIBI (740 MBq). For PET, scans were acquired 45-60 min after the injection of FDG (370 MBq) and attentuation correction was performed following transmission scans. Results from SMM and PET were subsequently compared with the histopathology results. True-positive results were obtained in 12/13 primary breast cancers (mean diameter=29 mm, range 8-53 mm) with both FDG and MIBI. False-negative results were obtained in two local recurrences (diameter <9 mm) with both FDG and MIBI. In benign disease, FDG and MIBI did not localize three fibrocystic lesions, two fibroadenomas and one inflammatory lesion (true-negative), but both localized one fibroadenoma (false-positive). Collectively, the results demonstrate a sensitivity of 92%, and a specificity of 86%, for primary breast cancer regardless of whether FDG or MIBI was used. In contrast to MIBI scintigraphy, FDG PET scored the axillae correctly as either positive (metastatic disease) or negative (no axillary disease) in all 12 patients. The tumour/non-tumour ratio for MIBI was 1.97 (range 1.43-3.1). The mean standard uptake value (SUV) for FDG uptake was 2.57 (range 0.3-6.2). The diagnostic accuracy of SMM was equivalent to that of FDG PET for the detection of primary breast cancer. For the detection of in situ lymph node metastases of the axilla, FDG seems to be more sensitive than 99mTc-MIBI.

Axilla↗
PubMed1997

Technetium-99m (V)-dimercaptosuccinic acid: normal accumulation in the breasts.

Technetium-99m (V)-dimercaptosuccinic acid (DMSA) is a tumour-imaging agent which has been used to evaluate medullary thyroid cancer and soft tissue tumours. Physiological uptake has been demonstrated in the kidneys, nasal mucosa and blood pool. In addition to positive accumulation in these sites, uptake in the breasts has been noted. The purpose of this retrospective study was to evaluate the accumulation of 99mTc (V)-DMSA in the normal breasts of 83 patients. There was no accumulation in male breasts. On the other hand, 24 of 51 female patients showed bilateral symmetrical accumulation in the breasts. Positive uptake was seen in 16 of 23 patients (70%) between 15 and 50 years old, but in only 7 of 25 (28%) above 50 years old. One out of three patients (33%) under 15 years old showed positive breast uptake. In conclusion, the female breasts should be included in the description of a pattern of normal biodistribution of 99mTc (V)-DMSA.

Adolescent↗
PubMed1997

The effect of chemotherapy on the uptake of technetium-99m sestamibi in breast cancer.

Technetium-99m sestamibi scintimammography has been used primarily in the diagnosis of breast cancer. It has also been suggested that this technique could be used to monitor response to chemotherapy and possibly to predict those patients in whom no response can be expected. An initial study was performed in nine patients with primary breast cancer. All patients underwent prone lateral and anterior 99mTc-sestamibi imaging at diagnosis and 4-7 months later, after they had received cytotoxic chemotherapy. The uptake of 99mTc-sestamibi in the breast was compared with that in normal surrounding breast tissue and this ratio was expressed as the target to background ratio. In all patients treated there was a reduction in uptake of 99mTc-sestamibi after treatment, such that whilst all the tumours could be seen before treatment, only three were visible following chemotherapy. There was a significant fall in the mean target to background ratio of the patients undergoing chemotherapy: the tumour to background ratio was 2.48 before chemotherapy and 1.40 after treatment (P<0.001, paired Student's t test). This fall in tumour activity was observed both in those patients in whom a clinical response was seen and in the two patients in whom the tumour enlarged despite chemotherapy. It appears that the reduced uptake of 99mTc-sestamibi seen after chemotherapy may be a non-specific change and therefore may not be predictive of the clinical response to treatment.

Adult↗
PubMed1996

Technetium-99m hexamethylpropylene amine oxime leucocyte scintigraphy in the early course of mild acute pancreatitis following endoscopic retrograde cholangiopancreatography.

We evaluated the diagnostic accuracy of technetium-99m hexamethylpropylene amine oxime (HMPAO) leucocyte scintigraphy in mild acute pancreatitis. A study design was chosen that gave us an opportunity to assess patients by leucocyte scintigraphy in the very early course of the disease. Thirty-two consecutive patients referred for endoscopic retrograde cholangiopancreatography were followed according to a very rigid protocol with laboratory tests and clinical examination before and after the endoscopic procedure and leucocyte scintigraphy [including single-photon emission tomography (SPET)] performed within 24 h. Planar and SPET images were examined by two observers who were blinded to each other and to the clinical history and diagnosis. Eight (25%) of the 32 patients developed mild acute pancreatitis, and only one of these patients had a positive scan. Sensitivity, specificity and accuracy of 13%, 79% and 63%, respectively, were achieved when both planar and SPET images were considered. When only planar images were considered the sensitivity, specificity and accuracy were 13%, 96% and 75%, respectively. No evidence of pathological leucocyte accumulation in mild acute pancreatitis was found despite the aforementioned very rigid protocol, allowing patients to be assessed by 99mTc-HMPAO leucocyte scintigraphy in the very early phase of the disease (this was true even when using SPET). From a clinical point of view, we believe that leucocyte scintigraphy should be used only when the disease is moderate or severe and serious intra-abdominal complications are suspected.

Acute Disease↗
PubMed1996

Age-related changes in the global skeletal uptake of technetium-99m methylene diphosphonate in healthy women.

A short-term evaluation of global skeletal uptake (GSU) of technetium-99m methylene diphosphonate (MDP) was performed in 40 healthy female subjects with a wide age range in order to investigate the clinical performance of the technique and to detect the age-related changes in bone turnover. The results obtained were compared with measurements of the main biochemical markers of skeletal metabolism. We found that GSU increases progressively with age, independently of concomitant changes in renal function; significant correlations with biochemical markers of bone formation were also found. Therefore, the method appears to provide useful information concerning the bone turnover rate, and is also applicable to elderly people owing to its simplicity.

Adult↗
PubMed1995

Technetium-99m sestamibi kinetics in reperfused canine myocardium.

The purpose of the current study was to clarify the myocardial kinetics of technetium-99m sestamibi when the latter is administered during reperfusion. Sestamibi has in the past been given to patients following thrombolytic therapy to document reperfusion and assess salvage. However, the factors which affect sestamibi kinetics during reperfusion are not clearly defined. In this study the left circumflex coronary artery was occluded for 2 h in six dogs (group 1) and for 3 h in six dogs (group 2), followed by reperfusion. Five additional dogs were not reperfused (group 3). Sestamibi was administered during reperfusion in groups 1 and 2, and during ongoing occlusion in group 3. Regional myocardial sestamibi activity was monitored for 3 h using miniature implanted radiation detectors and gamma camera imaging. Group 1 dogs had no infarcts, group 2 had moderate infarcts (mean: 13.9%), and group 3 had large infarcts (mean: 25.2%). Three-hour fractional myocardial clearances were significantly greater for reperfused infarcted (group 2) (0.23 +/- 0.02 SEM) and for nonreperfused infarcted myocardium (group 3) (0.24 +/- 0.02) compared to control (0.10 +/- 0.01) and reperfused noninfarcted myocardium (group 1) (0.07 +/- 0.02; P < 0.01). Quantitative image analysis demonstrated a significant reduction in the left circumflex/left anterior descending count ratios from initial to final scans for group 2 (0.74 +/- 0.03 to 0.65 +/- 0.03, P < 0.05), and a trend towards a reduction in the count ratios from initial to final scans for group 3 (0.38 +/- 0.04 to 0.30 +/- 0.04; P = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1995

Contribution of phagocytic cells and bacteria to the accumulation of technetium-99m labelled polyclonal human immunoglobulin at sites of inflammation.

The purpose of this study was to assess the contribution of phagocytic cells and bacteria to the accumulation of technetium-99m labelled polyclonal human immunoglobulin (HIG) at sites of inflammation. Mice were intraperitoneally injected with Staphylococcus aureus (SA animals), with heat-inactivated newborn calf serum (NBCS, to mimic a non-bacterial inflammation) or with physiological saline (controls); 1 h thereafter they received HIG. At various intervals after the administration of HIG the mice were killed, and the percentages of radioactivity in the peritoneal effluent and attached to the cellular and bacterial fraction thereof were established. Furthermore, the total number of cells and that of bacteria in the fluid were quantitated. The percentage of activity in the effluent in the SA animals was (P < 0.02) higher than those in the NBCS-injected animals and controls from 4 h onwards. In all groups of mice this percentage was highest at 4 h and decreased (P < 0.01) afterwards. The percentage of cell-bound activity and the total number of cells remained fairly constant or increased with time in the SA animals (P < 0.01). The bacteria-bound activity remained rather constant throughout the experiment and ranged between 4% and 6%. In the SA-infected animals the percentage of cell-bound activity was correlated with the total number of cells (macrophages but especially neutrophils) but even more strongly with the number of cell-associated bacteria. In the NBCS-injected animals a correlation was demonstrated between the cell-bound activity and the total number of cells (only neutrophils).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Experience with the iodine-123 and technetium-99m labelled anti-granulocyte antibody MAb47: a comparison of labelling methods.

Four different methods of radiolabelling the anti-granulocyte monoclonal antibody MAb47 were compared and their influence on diagnostic value studied. The best clinical images were obtained following labelling with iodine-123 by the Iodogen method and direct labelling with technetium-99m after tris-(carboxyethyl)-phosphine treatment of MAb47 to achieve disulphide bridge reduction. 99mTc labelling using a specific ligand (MAb47-mtp), or a second method involving direct reduction with mercaptoethanol, led to an increased background activity in clinical studies, thus impeding the diagnosis of chronic disease. Fresh infections were clearly localized by all four preparations. The elimination of the activity from the blood was slower in the case of the iodinated MAb47, while the collected urine samples showed an excretion of about 10% of the injected activity per day independent of the labelling method. The results in terms of sensitivity and specificity were rather similar for all labelling methods and ranged from 90% to 99%.

Abscess↗
PubMed1997

Clinical evaluation of technetium-99m infecton for the localisation of bacterial infection.

The aim of the study was to distinguish infection from inflammation in patients with suspected infection using technetium-99m Infecton. Ninety-nine patients (102 studies) referred for infection evaluation underwent imaging with 400 MBq 99mTc-Infecton at 1 and 4 h. Most patients had appropriate microbiological tests and about half (56) had radiolabelled white cell scans as well. No adverse effects were noted in any patient. The clinical efficacy of 99mTc-Infecton depended in part on whether imaging was undertaken during antibiotic therapy for infection or not. In consultation with the microbiologist, 5-14 days of appropriate and successful antibiotic therapy was considered adequate to classify some results as true-negatives. The figures for sensitivity and specificity of 99mTc-Infecton for active or unsuccessfully treated infection were 83% and 91% respectively. It is concluded that 99mTc-Infecton imaging contributed to the differential diagnosis of inflammation. It is being used as the first imaging modality when bacterial infection is suspected.

Adolescent↗
PubMed1990

Pulmonary clearance of technetium 99m diethylene triamine penta-acetic acid aerosol in patients with amiodarone pneumonitis.

Amiodarone pneumonitis is a serious complication that may lead to fatal lung fibrosis. In an attempt to diagnose this condition as early as possible, the technetium-99m-labelled diethylene triamine penta-acetic acid (99mTc-DTPA) aerosol washout rates of 10 non-smoking normal volunteers (group 1), 10 non-smoking patients on a long-term amiodarone regimen with dilated cardiomyopathy but no congestive heart failure (group II) and 10 patients with amiodarone pneumonitis (group III) were compared. Spirometric measurements, as percentage predicted, were higher in group I than in group III (P less than 0.05). The global mean effective half-lives of 99mTc-DTPA aerosol for both lungs together in minutes were 65 +/- 14, 55 +/- 16 and 27 +/- 4 for groups I, II and III, respectively. Group III values were significantly lower than those of groups I and II (P less than 0.05). Our results demonstrated that amiodarone pneumonitis alters the alveolar-capillary membrane permeability to hydrophilic molecules. The pulmonary clearance of 99mTc-DTPA aerosol is a useful test in the differentiation of patients on a long-term amiodarone regimen without side effects from patients with amiodarone pneumonitis. The test is rapid, easy to perform and has the potential for playing an important role in deciding which patients should discontinue therapy.

Aerosols↗
PubMed1990

Diffuse increase in renal uptake of technetium 99m methylene diphosphonate in association with disseminated cholangiocarcinoma.

A 48-year-old woman presented with disseminated cholangiocarcinoma and diffuse joint pain. A technetium 99m methylene diphosphonate bone scan revealed no bony abnormality, but intense bilateral renal uptake was seen. There was temporary renal impairment following imaging, but the cause of this is uncertain. An association between cholangiocarcinoma and 'hot kidneys' on bone imaging scanning has not been previously reported.

Adenoma, Bile Duct↗
PubMed1990

European multi-centre comparison of thallium 201 and technetium 99m methoxyisobutylisonitrile in ischaemic heart disease.

Fifty-six patients in Europe were entered into a multi-centre study to compare the accuracy of technetium 99m methoxyisobutylisonitrile (99mTc-MIBI) for the detection of coronary artery disease (CAD) with thallium 201 (201Tl) chloride perfusion scanning. The results showed a high degree of concordance between the two radiopharmaceuticals. Some 81% (678/840) of myocardial segments showed the same result (normal, infarct or ischaemia), and 80% (45/56) of patients had the same diagnosis. Overall detection of CAD in patients was 98% for 201T1 and 96% for 99mTc-MIBI. Detection of CAD in total arteries was 68% for both agents. In this study 99mTc-MIBI was as accurate as 201Tl for the detection of coronary artery stenoses.

Contrast Media↗
PubMed1980

Complementary use of computerized tomography and technetium scanning in the diagnosis of accessory spleen.

A patient with a previous splenectomy presented with acute gastrointestinal bleeding. He was found to have a benign gastric ulcer, esophagogastric varices, and a mass indenting the gastric fundus. Abdominal computerized tomography and technetium liver-spleen scanning established the diagnosis of an accessory spleen as cause for the mass effect. This diagnostic approach obviated the need for arteriography and exploratory laparotomy.

Congenital Abnormalities↗
PubMed1996

Is image subtraction necessary in the clinical interpretation of single-day split-dose stress cerebral perfusion single-photon emission tomography using technetium-99m compounds?

The aim of this study was to validate a simplified semiquantitative method of evaluating a single-day stress cerebral perfusion test to obtain cerebrovascular reserve capacity (CVRC) for routine clinical uses. A split-dose protocol was tested in 36 pairs of technetium-99m hexamethylpropylene amino oxime baseline (low dose) and acetazolamide (high dose) stress brain single-photon emission tomographic (SPET) studies from 16 patients with cerebrovascular disease. The images were displayed on a semiquantitative color scale with (corrected) and without (uncorrected) image subtraction, dose adjustment, and decay correction. The representative CVRC was determined by placing 3x3 pixel regions of interest on midthalamic and midcerebellar slices. The corrected and uncorrected relative changes in CVRC were correlated using linear regression. The relative changes of corrected (x) and uncorrected (y) CVRC by quantitative analysis were highly correlated in a linear fashion (y=0.67x+0.002, r=0.998, P<0.0005). As predicted by theory, the slope was related to the ratio of split dose and independent of ROI sampling. Single-day split-dose stress brain SPET can be accurately performed without image subtraction and complicated dose adjustment or decay correction for clinical studies.

Acetazolamide↗
PubMed1996

Is the addition of ECG gating to technetium-99m sestamibi SPET of value in the assessment of myocardial viability? An evaluation based on two-dimensional echocardiography following revascularization.

The main goal of this study was to evaluate whether the addition of ECG gating to technetium-99m sestamibi single-photon emission tomographic (SPET) perfusion imaging assists the prediction of recovery of regional wall motion abnormalities after revascularization. Thirty-six patients with coronary artery disease were included in the study. All had wall motion abnormalities, and 31 (86%) had a clinical history of myocardial infarction. Coronary artery bypass surgery was performed in 18 patients and angioplasty in the remainder. All underwent ECG-gated and non-gated SPET at rest and after intravenous dipyridamole. Two-dimensional echocardiography was performed at a mean of 27 days before revascularization and at a mean of 69 days following revascularization to assess segmental wall motion changes. Perfusion prior to revascularization was analysed qualitatively and quantitatively on gated and non-gated SPET, and the results compared with those of echocardiography. Bullseye parameters were obtained from a normal database, generated from data in 40 normal volunteers, using dipyridamole ECG-gated and non-gated sestamibi SPET. There was good concordance between gated and non-gated qualitative analysis (79% with kappa=0.65) for normal, viable or necrotic segments. Gated SPET predicted functional recovery in 27 of 35 (77%) segments showing echocardiographic improvement while non-gated SPET did so in 30 of 39 (77%) such segments. Gated SPET predicted no functional recovery in 20 of 45 (44%) segments that did not show improved wall motion after revascularization, while with non-gated SPET the figure was 18 of 51 (35%). The positive predictive values of gated and non-gated SPET with regard to the recovery of wall motion following revascularization were 52% and 48%, while the negative predictive values were 71% and 67%, respectively. 99mTc-sestamibi had a low predictive value for recovery of function if visual assessment was used in the analysis of SPET data. Quantitative bullseye sestamibi parameters (defect extension and severity, reversibility and percentage change in extension), from gated or non-gated studies, appear best to distinguish which segments will display improved motility on the echocardiogram after revascularization. The addition of ECG gating does not significantly increase the predictive value of SPET imaging with regard to recovery of function.

Angioplasty, Balloon, Coronary↗
PubMed1998

Technetium-99m human immunoglobulin imaging in patients with subacromial impingement or adhesive capsulitis.

Although recognised as useful in detecting soft-tissue inflammation and infection, technetium-99m human immunoglobulin (Tc-99m HIG) has not been widely studied in evaluating regional inflammatory musculoskeletal conditions. Tc-99m HIG scintigraphy was undertaken for consecutive patients referred to a rheumatology clinic with unilateral shoulder pain, diagnosed with either subacromial impingement (n = 12) or adhesive capsulitis (n = 4) from clinical examination, radiographic, and in some cases arthrographic findings. In all patients there were no differences in Tc-99m HIG images between symptomatic and asymptomatic shoulders. The findings are discussed, with reference to patterns of tissue inflammation which have been associated with each of the two conditions and in the context of patients referred to hospital relatively late after onset of symptoms (4-6 months).

Bursitis↗