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.

SourceResearch connectionFrom yearThrough year

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

At least 955 records · Page 53Linked to original sources

PubMed1996

Detection of axillary lymph node metastases in breast carcinoma by technetium-99m sestamibi breast scintigraphy, ultrasound and conventional mammography.

Axillary lymph node status is important in the staging of breast carcinoma. To evaluate the accuracy of technetium-99m sestamibi breast scintigraphy in detecting metastatic axillary lymph nodes as compared with other accepted imaging modalities, we performed 99mTc-sestamibi breast scintigraphy, conventional mammography and ultrasound in 36 patients with primary untreated breast carcinoma. With histopathology as the gold standard, 99mTc-sestamibi breast scintigraphy was found to yield true-positive results in 7 of 11 cases (64%) of axillary lymph node metastases and true-negative results in 18 of 20 cases (90%); it has an accuracy of 81%, a positive predictive value of 77.8% and a negative predictive value of 81.8%.

Axilla↗

PubMed1996

Comparison of technetium-99m sestamibi left ventricular wall motion and perfusion studies with thallium-201 perfusion imaging: in search of the combination of variables with the highest accuracy in predicting coronary artery disease.

Measurements of myocardial perfusion and ventricular function are expected to provide additional information in the detection of coronary artery disease (CAD). The purpose of this study was threefold: (1) to determine to what extent technetium-99m sestamibi wall motion yields different information compared with 99mTc-sestamibi and thallium-201 perfusion; (2) to test which information unique to either study is of value in diagnosing CAD; and (3) to assess the combination of variables with the highest diagnostic accuracy. Perfusion and wall motion scores (at rest and during exercise) obtained from visual and quantitative planar 201Tl and 99mTc-sestamibi scintigraphy of 60 patients with suspected CAD were compared with the angiographic results by means of a polytomous logistic regression model and the diagnostic values were compared with one another. All univariate variables were significantly related to the probability of CAD and its extent. Comparative studies revealed a large degree of correlation between 201Tl stress and redistribution variables. The rest 99mTc-sestamibi and wall motion studies contained partially different information. Stepwise logistic regression analysis showed the strongest diagnostic power for the combination of 201Tl visual analysis of the stress images with quantitative redistribution images (sensitivity 93%, specificity 71%). The diagnostic power was similar for all combinations of visual and quantitative analyses of the exercise and redistribution images. The strongest diagnostic power of the 99mTc-sestamibi variables was the score of the diastolic stress image (sensitivity 91%, specificity 79%). Comparable sensitivity and specificity estimates were found when both optimal models were compared. Wall motion studies did not have additional diagnostic power. Although 99mTc-sestamibi wall motion studies, both at rest and during exercise, provide information in addition to the 99mTc-sestamibi or 201Tl myocardial perfusion variables, the information does not enhance the diagnostic power with regard to the prediction of CAD.

Coronary Angiography↗

PubMed1996

Technetium-99m sestamibi uptake in human breast carcinoma cell lines displaying glutathione-associated drug-resistance.

An in vitro study was designed to evaluate the uptake of sestamibi (MIBI) in P-glycoprotein (Pgp) and glutathione-associated (GSH) multidrug-resistant (MDR) cell lines. MIBI uptake was studied in various human breast carcinoma cell lines, i.e. in wild-type (MCF7/wt) cells, in adriamycin-resistant (MCF7/adr) cells which express Pgp and in melphalan-resistant (MCF7/mph) cells with increased levels of GSH. The effects of buthiomine sulphoximine (BSO) and verapamil on MIBI uptake were also studied in the MCF7/mph and MCF7/adr cells respectively. The cells were incubated for 1 h with a dose of 0.1 MBq thallium-201 and technetium-99m MIBI. Both MIBI and 201Tl uptakes were higher for MCF7/mph cells than for the other cells studied. The mean MIBI uptake in MCF7/adr cells was significantly lower than that in MCF7/wt cells (1.9%+/-0.5% vs 3. 1%.0.6%; P <0.01). Verapamil treatment increased the MIBI uptake in MCF7/adr cells (to 2.6%.0.3%; P <0.05). Treatment of MCF7/mph cells with BSO resulted in a significant reduction in GSH content (from 243.2+/-81.1 nmol/mg protein to 17.6+/-4.4 nmol/mg protein; P <0. 001). However, MIBI uptake in BSO-treated and untreated MCF7/mph cells was similar (4.43%+/-0.5% and 5.93%+/-1.7%, respectively; P >0. 1). This study suggests that the uptake of MIBI is not diminished by glutathione-associated drug resistance and that MIBI uptake in a tumour sample does not necessarily indicate that a cancer is sensitive to drugs.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1996

Value of radioimmunoscintigraphy with technetium-99m labelled anti-CEA monoclonal antibody (BW431/26) in the detection of colorectal cancer.

This study was undertaken as part of a Coordinated Research Programme initiated by the International Atomic Energy Agency to evaluate the usefulness of radioimmunoscintigraphy (RIS) in the management of patients with colorectal cancer. Technetium-99m labelled BW431/26, a monoclonal antibody against carcinoembryonic antigen (CEA), was used. The study included 73 patients (31 females and 42 males). Sixty-eight patients were suspected of having recurrent colorectal adenocarcinoma while another five were suspected to have primary colorectal cancer. Images were acquired at 10 min and 4 and 24 h following the injection of radioantibody. The efficacy of RIS in tumour detection was evaluated by the findings at surgery, histological investigation and/or other diagnostic modalities and clinical follow-up. Four of five patients with suspected primary colorectal cancer gave true-positive results (three at primary sites, one at the site of a metastatic lesion) while one was false-positive. The overall accuracy of RIS in the diagnosis of recurrent colorectal cancer was 87%. Its sensitivity in the detection of locoregional or abdominal recurrence and liver metastases was 97% and 89% respectively. RIS was more accurate than computed tomography (CT) scan in the detection of pelvic recurrence and liver metastases while CT scan was far superior to RIS in detecting lung metastases. RIS proved most useful in patents who had rising CEA levels on clinical follow-up but in whom other work-up, including CT scan, was negative. The advantages of RIS include the ability to detect tumour recurrence prior to other investigations and to identify tumour recurrence in areas such as the pelvis, where CT and magnetic resonance imaging have their greatest weaknesses in diagnosing recurrent disease. The imaging accuracy is significantly increased when combined CT and antibody imaging is performed.

Adenocarcinoma↗

PubMed1996

Labelling of leucocytes with technetium-99m exametazime causes in vitro upregulation of granulocyte CD11b without correlation to tissue uptake in vivo.

The aims of this study were to investigate whether labelling with technetium-99m exametazime alters the expression of adhesion molecule CD11b on granulocytes and monocytes, and to study whether the expression of CD11b on unlabelled or labelled cells correlates with uptake of the labelled cells in the inflamed bowel, in the lungs or in the reticuloendothelial system. Leucocytes were obtained from 25 patients with inflammatory bowel disease who underwent leucocyte scan. The cellular expression of CD11b was analysed using flow cytometry. Labelling with 99mTc-exametazime induced an increased surface expression of CD11b on granulocytes (P<0.01), but not on monocytes. The increase in CD11b expression on granulocytes was lower than the spontaneous mobilization that occurred at 37 degrees C and correlated neither with this, nor with N-formyl-methionyl-phenylalanine induced expression of the same receptor. Basal expression of CD11b on unlabelled granulocytes, but not on monocytes, correlated with bowel and lung uptake 45 min after reinjection of labelled cells, but not with uptake on later images. No correlation was found between the CD11b expression on labelled granulocytes or monocytes and scintigraphic uptake. Our findings show that labelling with 99mTc-exametazime increases the expression of adhesion protein CD11b on granulocytes. The increase in surface expression of CD11b does not correlate with the scintigraphic uptake of labelled cells in the bowel, in the lungs or in the reticuloendothelial system.

Adult↗

PubMed1996

Technetium-99m scintigraphy: more accurate assessment of ulcerative colitis with exametazime-labelled leucocytes than with antigranulocyte antibodies.

To compare two technetium-99m scintigraphic techniques - 99mTc-labelled antibodies against granulocyte non-specific cross-reacting antigen-95 and 99mTc-exametazime labelled leucocytes in ulcerative colitis - 23 consecutive patients undergoing colonoscopy were investigated in a prospective and randomized study. In each patient the two scans and colonoscopy and biopsy were performed within 10 days. Scans, endoscopy and histology were independently graded for degree of inflammation in eight different colorectal segments for each patient. Active inflammation in one or more segments was present on endoscopy in 22 patients and on histology in 17 patients. Twenty-two patients had increased uptake on the antibody scan and 21 patients on the exametazime scan. Twelve patients showed the same disease extent with both scan methods (total colitis, n=10; distal colitis, n=2). Compared with endoscopy, sensitivity for inflammation in individual segments was 0.51 for antibody scan and 0.87 for exametazime scan; specificity was 0.67 and 0.55, respectively. The predictive value for presence of inflammation was 0.66 for antibody scan and 0.72 for exametazime; the predictive value for absence of inflammation was 0.52 and 0.77, respectively. Segmental scan uptake of endoscopically or histologically visualized inflammation was consistently lower for antigranulocyte antibodies than for exametazime. It is concluded that in patients with active ulcerative colitis, inflammation is better visualized with 99mTc-exametazime labelled leucocytes than with 99mTc-labelled antigranulocyte antibodies. The antibody technique offers the advantage of in vivo labelling, but is less reliable than the exametazime method for imaging of colonic inflammation.

Adolescent↗

PubMed1995

Labelling of leucocytes with colloidal technetium-99m-SnF2: an investigation of the labelling process by autoradiography.

Autoradiography of smears and frozen sections of labelled cell suspensions was used to study the distribution of radioactivity in and among blood cells labelled in either whole blood or leucocyte-rich plasma (LRP) with technetium-99m-SnF2 colloid. The tracer proved selective for neutrophils: the labelling probability (relative to that for erythrocytes) for each cell type in LRP (mean of five samples) was: neutrophils, 9.4; lymphocytes, 3.7; monocytes, 3.0; eosinophils 1.4; erythrocytes, 1.0. When labelling was carried out in whole blood (five samples), 74.5% +/- 8.3% of the cell-bound radioactivity was bound to erythrocytes, 13.6% +/- 6.5% to neutrophils, and 11.9% +/- 2.1% to lymphocytes, whereas in LRP (in which the leucocytes were only slightly outnumbered by erythrocytes), 76.5% +/- 14.9% of radioactivity was neutrophil bound. Labelled cells in smear autoradiographs exhibited two distinct silver grain patterns, "diffuse", consistent with an intracellular radioactive particle (in neutrophils), and "focal", consistent with a cell surface-adhering particle in direct contact with the emulsion (in other leucocyte types and erythrocytes). The phagocytic inhibitor cytochalasin B neither reduced the proportion of labelled neutrophils nor altered the labelling pattern. Neutrophils were able to scavenge radioactivity from the surface of erythrocytes. It is concluded that neutrophils bind 99mTc-SnF2 intracellularly by phagocytosis, with high affinity; other cells become labelled at the cell surface reversibly and with lower affinity. This selectivity is high enough to permit predominantly leucocyte labelling in LRP but not in whole blood.

Autoradiography↗

PubMed1995

Comparison of technetium-99m methoxyisobutylisonitrile and gallium-67 citrate scanning in the assessment of lymphomas.

The aim of this study was to compare the value of scintigraphy using technetium-99m methoxyisobutylisonitrile (MIBI) with that of scintigraphy using gallium-67 citrate in the assessment of Hodgkin's disease and non-Hodgkin's lymphoma and to relate these results with those of CT scan and MRI. Fifty-eight patients were included either for a follow-up examination or for monitoring of their treatment. Twenty-three residual masses were studied. A whole-body scan was performed, followed by single-photon emission computed tomography (SPET) 20 min after injection of 740 MBq of 99mTc-MIBI and 72 h after injection of 185 MBq of 67Ga citrate. The overall sensitivity of 99mTc-MIBI and 67Ga citrate was 71% and 68%, respectively, and the overall specificity was 76% and 44%, respectively. For residual masses, the sensitivity was 44% with both tracers and the specificity was 80% with 99mTc-MIBI and 53% with 67Ga citrate. The positive predictive values were 85% and 68% and the negative predictive values were 59% and 44%, respectively. The signal-to-background ratio was 1.5 for 99mTc-MIBI and 2 for 67Ga citrate. At present, 99mTc-MIBI cannot replace 67Ga citrate in the assessment of lymphomas.

Adult↗

PubMed1995

Application of technetium-99m hexamethylpropylene amine oxime single-photon emission tomography to neurologic prognosis in patients undergoing urgent carotid surgery.

In this study we aimed to work out a quantitative prognostic index for preoperative assessment of brain technetium-99m hexamethylpropylene amine oxime (HMPAO) single-photon emission tomography (SPET) in patients referred for urgent carotid endarterectomy due to acute obstructive disease of the internal carotid artery (ICA) and neurological deficit. To this end we compared data from preoperative SPET studies with the postinterventional changes in neurological status in 20 patients (17 males, three females; mean age 53 years, SD 4 years) with acute ischaemic cerebral disorders induced by obstruction of the ICA. Carotid obstruction was diagnosed by ultrasound B-mode study. All patients underwent urgent carotid endarterectomy from the ICA. Patients were divided into two groups in accordance with the results of postoperative follow-up: group A comprised patients with significant (more than 3 points) postoperative improvement in neurological condition as quantified by the Canadian Neurological Scale (11 patients); group B consisted of patients with minimal improvement or deterioration (nine, three of whom died). All patients were studied preoperatively by 99mTc-HMPAO SPET. The volume of nonperfused tissue (VS, cm3) was quantified using the Mountz technique. Hypoperfused volume (Vhypoperf, cm3) in the affected hemisphere was calculated as the total volume of voxels with 99mTc-HMPAO uptake < 90% of the contralateral symmetric voxels. Discriminant prognostic function was calculated by discriminant analysis as: PF = 0.072 x VS + 29.46x(VS/Vhypoperf). Patients with preoperative PF values < 8.20 demonstrated postoperative improvement in neurological status, while the group with PF > 8.90 comprised patients who demonstrated minimal improvement or deterioration. PF values in the range 8.20-8.90 carried an indefinite prognosis. We conclude that the preoperative 99mTc-HMPAO SPET can be used for the selection of patients in whom improvement in neurological status may be expected after urgent surgical correction of acute extracranial obstruction of the ICA.

Brain↗

PubMed1995

Clinical significance of technetium-99m methylene diphosphonate myocardial uptake: association with carcinoma of the prostate.

Benign myocardial uptake of technetium-99m labelled phosphates, not related to cardiac or metabolic disorders, has been documented except in the case of 99mTc-methylene diphosphonate (MDP). The aim of this study was to assess the frequency of myocardial uptake and its possible association with malignant tumours in general and prostatic carcinoma in particular. We reviewed bone scintigrams performed with either 99mTc-hydroxydiphosphonate (HDP) or 99mTc-MDP over a period of more than 2 years for all patients with prostatic carcinoma and a matching group of patients suffering from other malignant and non-malignant disorders. A total of 965 scintigrams of 812 patients (males = 559, females = 253; age range 50-91 years, average age 69.2 years) were reviewed. Increased myocardial uptake was detected in 19 scintigrams (MDP = 13, HDP = 6) of 18 patients (17 males, one female). Most of the male patients with increased myocardial uptake had prostatic carcinoma (13/17) and were over 80 years of age (12/17). All patients were free of any cardiac or noncardiac disorder that might account for such uptake. When scintigraphy was repeated in the same patient, the uptake of 99mTc-HDP was more diffuse and of higher grade than that of 99mTc-MDP. "Benign" myocardial uptake of 99mTc-MDP is more common than previously thought. Although uptake of radiophosphates is attributed to asymptomatic atherosclerotic changes associated with old age, a strong association with prostatic carcinoma exists which may indicate variations in the bone: soft tissue affinity of different MDP complexes.

Aged↗

PubMed1995

Sequential functional imaging with technetium-99m hexakis-2-methoxyisobutylisonitrile and indium-111 octreotide: can we predict the response to chemotherapy in small cell lung cancer?

A case of small cell lung carcinoma (SCLC) demonstrating uptake on functional indium-111 octreotide scintigraphy is presented. Technetium-99m hexakis-2-methoxyisobutylisonitrile (MIBI) scintigraphy clearly delineated an absence of radionuclide uptake at the tumour site. This suggested the presence of multidrug resistance-mediated P glycoprotein (Pgp) on tumour cells, which recognizes certain chemotherapeutic agents as well as MIBI as a substrate and avoids radionuclide concentration. Following three courses of chemotherapy, the patient failed to improve and eventually died. This case demonstrates the importance of functional images, which have the potential to predict the outcome in response to chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Technetium-99m HMPAO SPET in acute supratentorial ischaemic infarction, expressing deficits as millilitre of zero perfusion.

A comparative interim analysis was performed of clinical parameters, computed tomographic (CT) scan results and technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (SPET) findings obtained within 12 h of acute supratentorial ischaemic infarction. First, the applicability for SPET semiquantification in this study of the "method of Mountz", simultaneously accounting for extent and degrees of hypoperfusion by expressing deficits as millilitre of zero perfusion, was considered. Next, the relative contributions of perfusion SPET and CT scan in the acute stage of ischaemic infarction were compared in 27 patients (mean age 68.8 years). Finally, the correlation of SPET lesions with clinical parameters at onset was evaluated. The method of Mountz represents a workable, accurate virtual parameter, with the assumption that the contralateral brain region remains uninvolved. Interobserver reproducibility in 12 SPET studies, with lesions varying between 6 and 369 cc, showed a correlation coefficient r of 0.99. In practice, because of inconstant distribution of activities in the brain, the method can only be applied slice by slice and not on the total global volume. While the mean delay since the onset of symptomatology was approximately 7 h for both SPET and CT scan, SPET showed lesions concordant with the clinical neurological findings in 100% and CT scan in only 48%. One could hypothesize that SPET examinations performed later would show larger functional defects, because of the development of additional functional changes secondary to biochemical alterations. However, in this regard no statistically significant differences were found between two subproups, taking the median of delay before SPET examination as cut-off.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1995

Simultaneous dual-isotope technetium-99m/thallium-201 cardiac SPET imaging using a projection-dependent spilldown correction factor.

A spilldown correction method is proposed for the thallium-201 window image in simultaneous dual-isotope technetium-99m/thallium-201 single-photon emission tomographic (SPET) imaging based on a single acquisition into three energy windows. In this method, images are simultaneously acquired in two standard energy windows over the 99mTc and 201Tl photopeak regions and a third spilldown window adjacent to the 201Tl window. Using a Monte Carlo simulation of SPET, the fractional amount of 99mTc and 201Tl spilldown in the 201Tl window with respect to the total counts from the spilldown window, k12, was calculated for simulated images of point sources at varying depths within a water-filled elliptical tub phantom. When applied to experimental acquisitions, k12, multiplied by the total counts from the spilldown window, is then subtracted from the 201Tl window image to produce the corrected image. However, for successful applications in SPET, k12 must be determined on a projection-by-projection basis since k12 is depth dependent. Thus, a regression relation was obtained between k12 and the total count ratio of the spilldown to 99mTc windows, k23. The spilldown correction method was applied to 201Tl photopeak images of an extended source distribution in uniform and nonuniform attenuating media with dual-isotope 99mTc/201Tl and single-isotope 201Tl. A marked improvement in image contrast was observed between the corrected and uncorrected 201Tl window images. The average count ratio of uncorrected dual-isotope 201Tl/single-isotope 201Tl was 3.08 for uniform and 2.99 for non-uniform attenuating media.(ABSTRACT TRUNCATED AT 250 WORDS)

Heart↗

PubMed1996

Comparative study of rest technetium-99m sestamibi SPET and low-dose dobutamine stress echocardiography for the early assessment of myocardial viability after acute myocardial infarction: importance of the severity of the infarct-related stenosis.

Rest technetium-99m sestamibi single-photon emission tomography (SPET) has been shown to underestimate viability in some patients with chronic ischaemic myocardial dysfunction. The present study was designed to appraise the value of 99mTc-sestamibi as a viability tracer in patients with a recent myocardial infarction and to determine factors that might influence its accuracy in assessing infarct size. Therefore, rest 99mTc-sestamibi SPET, low-dose dobutamines stress echocardiography and quantitative coronary angiography were performed in 51 patients with a recent myocardial infarction. Perfusion activity and regional wall motion were scored semi-quantitatively using the same segmental division of the left ventricle. Assessment of 99mTc-sestamibi uptake as a marker of viability was performed by comparing a binary uptake score (viable=>50% vs necrotic =</=50% of the maximal tracer activity) with a binary wall motion classification during low-dose dobutamine infusion (viable=normal/hypokinetic vs necrotic=akinetic/dyskinetic). Infarct size, expressed as the number of segments with evidence of necrotic tissue, was significantly greater in the scintigraphic study than in the echocardiographic study (2.8+/-1.5 vs 2.2+/-1.3, P=0.006). This overestimation of infarct size by 99mTc-sestamibi was present only in patients with a severe infarct-related stenosis (% diameter stenosis >/=65%-100%) and particularly those with "late" reperfusion therapy (time delay >/=180 min). In patients without a severe infarct-related stenosis, 99mTc-sestamibi was able to accurately distinguish viable from necrotic segments. Thus, rest 99mTc-sestamibi scintigraphy early after acute myocardial infarction may underestimate residual viability within the infarct region, particularly in patients with low flow state coronary anatomy, as a result of a severe infarct-related stenosis and/or late reperfusion therapy.

Cardiotonic Agents↗

PubMed1996

Optimal collimator choice for sequential iodine-123 and technetium-99m imaging.

Dual-isotope studies with technetium-99m and iodine-123 may be useful for various organs, including brain and myocardium. For the images obtained with each of the tracers to be comparable, it is important that activity ratios (activity in one part of the image/reference activity in the image) are preserved by the imaging method. We have used a Rollo phantom to study how collimator response affects such ratios. All investigations were performed with 123I(p,5n) and on a Siemens Orbiter 3700 camera fitted with either a low-energy high-resolution (LEHR) or a medium-energy (ME) collimator. Images were made of a Rollo phantom filled with an aqueous solution of either 99Tc or 123I, and placed on the collimator surface with 8 cm of methyl-methacrylate interposed. Count densities were measured in ROIs drawn in each cell of the phantom, and normalised to the maximal ROI value in the image. The mean square error (MSE) was used to assess how well the ratios of count densities approximated the known activity ratios based on the dimensions of the cells of the phantom. For 99mTc, regardless of the collimator used, the count density ratios approximated the activity ratios fairly well (LEHR: MSE=0.008; ME: MSE=0.020). For 123I, count density ratios obtained with the LEHR were consistently higher than activity ratios (MSE=0. 235), whereas the differences between the measured and the theoretical values were less with the ME collimator (MSE=0.013). Contrast fidelity of the 123I images obtained with the LEHR collimator could be improved with Jaszczak scatter correction with k=1, but this led to unfavourable signal-to-noise ratios. For sequential 99mTc/123I studies with extended sources, ME is to be preferred because of its higher contrast accuracy. Spatial resolution is less for the ME than for the LEHR collimator (FWHM with scatter: LEHR/99mTc=6.9 mm, LEHR/123I=7.4 mm, ME/99mTc= 10.1 mm, ME/123I=11.1 mm), but remains similar for both tracers when the ME is used.

Gamma Cameras↗

PubMed1997

Chronic complicated osteomyelitis of the appendicular skeleton: diagnosis with technetium-99m labelled monoclonal antigranulocyte antibody-immunoscintigraphy.

Chronic post-traumatic osteomyelitis (OM) represents a particular challenge for nuclear medicine and radiology since clinical and biochemical parameters are frequently unreliable. The aim of this study was to investigate the value of combined bone scan (BS) and immunoscintigraphy (IS) with technetium-99m labelled monoclonal antigranulocyte antibody (MAB) in patients with suspected chronic OM of the appendicular skeleton. Twenty-four patients (17 females and 7 males) with suspected chronic post-traumatic OM were evaluated with three-phase BS/99mTc-MAB-IS. The final diagnosis was established by means of bone culture and histology in 19 cases and clinical follow-up in five cases. The studies were reviewed by two independent and experienced observers; the interobserver agreement was calculated by kappa statistics. The sensitivity, specificity and accuracy of BS alone were 92%, 18% and 58%, respectively. Combined BS/99mTc-MAB-IS had a sensitivity, specificity and accuracy of 84%, 72% and 79%, respectively. Of 24 studies, 11 were true-positive, two false-negative, eight true-negative and three false-positive. Two patients presented with unexpected ectopic haematopoietic bone marrow in the appendicular skeleton that caused false-positive results. A high degree of interobserver agreement was found (kappa=0. 85). It is concluded that combined BS/99mTc-MAB-IS represents a very sensitive and reproducible method with an acceptable specificity for the investigation of chronic OM. Problems may occur in the differentiation of low-grade OM from aseptic inflammation. Another problem is ectopic marrow that may occur in the appendicular skeleton due to a chronic inflammatory stimulus. A former intramedullary intervention in the femur with displacement of haematopoietic marrow may also lead to an ectopic location.

Bone and Bones↗

PubMed1997

Non-invasive assessment of technetium-99m albumin transit time distribution in the pulmonary circulation by first-pass angiocardiography.

This study describes a non-invasive method for assessment of the lung transit time distribution of a tracer, using first-pass technetium-99m albumin angiocardiography and a model-free method of deconvolution. Ten patients received a first injection of 1 MBq kg-1 in the external jugular vein to position a gamma camera in the left anterior oblique position and two additional injections (5 MBq kg-1) to record first-pass angiocardiographic data. Right and left ventricular time-activity curves were derived from regions of interest every 0.5 s over a 1-min period. The left ventricular curve was deconvoluted by the right ventricular curve to obtain the lung transport function. The deconvolution procedure was based on a modified version of the Kalman filtering technique. The procedure was repeated at an interval of 30 min in eight patients. Two patients were re-examined up to 2 years later. Skewness, kurtosis and relative dispersion of the distributions did not change over time. We also found that the distribution, once normalized by its first moment, was independent of isolated changes in heart rate or cardiac output. Comparison of curve shapes at an interval of 30 min by point by point analysis demonstrated the reproducibility of the technique. We conclude that computation of the pulmonary transit time distribution of 99mTc-albumin from a standard angiocardiography procedure by model-free deconvolution is reliable and reproducible over time. We suggest that it may be a valuable tool for the non-invasive follow-up of the pulmonary circulation.

Adult↗

PubMed1997

Technetium-99m sestamibi leg scintigraphy for non-invasive assessment of propionyl-L-carnitine induced changes in skeletal muscle metabolism.

Carnitine derivatives, such as propionyl-l-carnitine (PLC), have been shown to improve walking distance in patients with obstructive peripheral artery disease (PAOD). The aim of this study was to ascertain whether technetium-99m sestamibi leg scintigraphy may be a useful tool in the evaluation of changes in skeletal muscle metabolism induced by chronic therapy with PLC. Twenty patients with clinical and instrumental evidence of PAOD were randomly assigned to a 3-month period of therapy with either PLC or placebo. Rest 99mTc-sestamibi leg scintigraphy and echo-Doppler sonography were performed on all subjects immediately before and upon completion of the treatment period. At the end of the protocol the following results were observed in patients who underwent PLC administration: (a) a significant increase in both thigh and calf 99mTc-sestamibi uptake, in comparison with baseline values (P<0.001); (b) the absence of statistically significant modifications of Doppler blood flow indices of the lower limbs. In conclusion, after chronic administration of PLC, a significant increment in skeletal muscle uptake of 99mTc-sestamibi was demonstrated without any apparent change in regional blood flow. This fact, if proven in further studies, may suggest a role for this tracer as a non-invasive probe of tissue bioenergetics.

Arterial Occlusive Diseases↗