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Biomedical subjects

J Setoain

Publications and source records attributed to J Setoain.

At least 55 records · Page 3Linked to original sources
PubMed1993

Evaluation of myocardial perfusion defects by means of "bull's eye" images.

The purpose of this study was to evaluate the usefulness of so-called "bull's eye" imaging as a simplified display of tomographic slices in the detection of coronary artery disease (CAD). A total of 64 patients were studied at stress and at rest, by single photon emission computed tomography (SPECT), either with thallium-201 (201Tl) or with technetium-99m methoxy-isobutyl-isonitril (Tc-MIBI). The myocardial perfusion defects detected by bull's eye image alone and in combination with visual analysis of tomographic images were evaluated in all cases, taking coronary arteriographic results as a gold standard. The overall sensitivity and specificity for detection of CAD were as follows: bull's eye imaging, 100% and 70.8%; tomographic imaging (SPECT), 90% and 91.6%. The results of bull's eye imaging and SPECT interpreted together were 96.6% and 83.3%. The regional sensitivity and specificity of bull's eye for individual coronary arteries were: right coronary artery (RCA), 100% and 73.7%; left anterior descending (LAD), 100% and 87.2%; left circumflex (LCx), 100% and 97.3%. For SPECT they were: RCA, 93.7% and 89.5%; LAD, 86.6% and 92.3%; LCx, 73.3% and 97.4%. For bull's eye with SPECT they were: RCA, 94.4% and 86.1%; LAD, 87.5% and 92.1%; LCx, 82.3% and 97.2%. We conclude that the bull's eye image display allows an easier and more objective assessment of myocardial perfusion defects and shows higher sensitivity. However, it has a relatively low specificity which can cause an overestimation of perfusion defects. Thus, visual analysis of bull's eye imaging is a useful diagnostic tool but must be evaluated in conjunction with tomographic imaging.

Adult↗
PubMed1993

Kinetics of hypodermically injected technetium-99m and correlation with cutaneous structures: an experimental study in dogs.

We investigated the involvement of cutaneous structures in specific linear migration pathways of technetium-99m pertechnetate hypodermically injected at points of low electrical resistance in the metacarpus of male beagles. Skin-deep incisions were made in the front or back legs on either the same side as the 99mTc injection or on the opposite side. Incisions in the back legs did not affect the migration pattern. Incisions in the front legs before the injection of 99mTc prevented tracer migration. After the injection of 99mTc, incisions in the front contralateral leg caused sudden cessation of the migration, while incisions in the ipsilateral leg caused immediate disappearance of the pathway previously observed. Radioactivity was not detected in flaps obtained from the skin overlying the migration pathway or from the corresponding area of the contralateral leg. In conclusion, the specific linear migration pathways of 99mTc hypodermically injected at points of low electrical resistance cannot be explained by any known biological function. Although the migration of 99mTc does not seem to be strongly linked to any cutaneous structure, the skin overlying the radioactive pathway and the corresponding area of the contralateral leg must be intact if tracer migration is to take place.

Animals↗
PubMed1993

Detection and quantitative analysis of joint activity inflammation with 99Tcm-polyclonal human immunoglobulin G.

99Tcm-polyclonal human immunoglobulin G (HIG) scintigraphy was used to detect active joint inflammation and to obtain ratios of joint uptake in noninvolved and inflammatory joints. Imaging was performed at 4 and 24 h in 16 patients with rheumatoid arthritis (RA) and 16 with degenerative joint disease (control group). All joints (total of 1344) were scored for pain, swelling and visual analysis of uptake in both scans. Joint to background (J:B) ratios were also calculated. Clinical and visual scores correlated in both scans (r = 0.7, P < 0.01). In RA patients, 246 joints were clinically involved. Visual analysis of scans detected 213 (87%) of them at 4 h and 196 (80%) at 24 h. Joints with no pain or swelling showed significantly higher J:B ratios than the control group and lower ratios than joints clinically involved. In the control group, statistically significant differences in J:B ratios between the various joints were found, so it was necessary to establish a normal range for every joint. J:B ratios were significantly higher at 4 h than at 24 h in both groups of patients. 99Tcm-HIG scintigraphy allows detection and measurement of joint inflammation. Scans performed at 4 h are preferable to scans at 24 h. Quantitative analysis can measure more objectively the degree of activity and could be useful in the management of these patients.

Aged↗
PubMed1993

Radioimmunoscintigraphy of colorectal carcinoma with a 111In-labelled anti-TAG-72 monoclonal antibody.

Radioimmunoscintigraphy (RIS) of colorectal carcinoma with a 111In-labelled anti-TAG-72 monoclonal antibody (CYT-103) has been performed in 24 patients with five primary lesions and 10 suspicious of recurrence (in one of these patients two RIS were made). Histopathological confirmation of the disease and surgical liver examination were carried out in all primary tumours and in 12 possible recurrences. In the remaining eight patients a final diagnosis was established according to the clinical course and other diagnostic procedures. Planar and tomographic scans were obtained at 48 and 72 h postinjection in all patients. All primary tumours were detected by RIS. In the group with recurrences confirmed pathologically the results were nine true positive, two true negative and one false positive in a patient affected only with liver disease. The nine true positive studies corresponded to four positive by computed tomography (CT), four negative by CT and one nonconclusive by CT. Surgical liver examination results were 15 true negative and two false negative. No correlation was found between serum levels of carcinoembryonic antigen or TAG-72 and the detection of the lesions. In 10 patients human anti-mouse antibody (HAMA) levels were studied. In conclusion, RIS with an anti-TAG-72 monoclonal antibody is a useful technique for the study and localization of colorectal tumours, mainly in cases of recurrence, being also indicated in patients with normal TAG-72 serum levels.

Aged↗
PubMed1992

Diagnostic value of technetium-99m-MIBI as a myocardial perfusion imaging agent: comparison of long and short intervals between rest and stress injections.

To assess the diagnostic value of technetium-99m-MIBI (99mTc-MIBI) as a myocardial perfusion imaging agent, and if rest and exercise scans could be performed on the same day, 21 patients with coronary artery disease were studied. Qualitative planar 201-thallium (201Tl) scans, coronary angiography, or both were also performed (median between studies 11 days). In 10 patients an injection of 740 mBq of 99mTc-MIBI at stress was followed by a second injection of 740 mBq at rest 24 h later (long interal) (LI). In 11 patients injection of 370 mBq at rest was followed 3 h later by an injection of 740 mBq at stress (short interval) (SI). Exercise scans were performed to similar maximal work load (LI = 6.6 +/- 1.8 METs; SI = 6.3 +/- 1.7 METs; 201Tl = 6.8 +/- 1.2 METs; p = NS) and double product (LI = 19551 +/- 7370; SI = 19900 +/- 6797; 201Tl = 19965 +/- 5282; p = NS). Overall, 99mTc-MIBI and 201Tl agreed in 92% of the patients tested and in 165 of 180 (92%) left ventricular segments in both 99mTc-MIBI protocols using short and long intervals between injections. In 15 patients with significant stenosis, 99mTc-MIBI correctly identified 13 patients (sensitivity of 87%). Thus, 99mTc-MIBI is a useful imaging agent with similar diagnostic value as 201Tl. In spite of its lack of myocardial redistribution, 99mTc-MIBI rest and exercise scans performed on the same day seem to have a similar concordance rate with 201Tl as when performed on separate days.

Adult↗
PubMed1992

Experimental study on radioactive pathways of hypodermically injected technetium-99m.

The objective of this study was to investigate the biological substrate of radioactive pathways of migration of hypodermically injected 99mTc into points of low electrical resistance. Sixteen anesthetized adult male beagles were used. Control and test points were defined by comparing their electrical resistance to that of the pinna. Seventy-three experiments of three different types were performed: (1) separate hypodermic injections of [99mTc] sodium pertechnetate, 201Tl-chloride, 131INa and 99mTc-rhenium sulfide into control and test points; (2) simultaneous injections of [99mTc]sodium pertechnetate and 201Tl chloride into control and test points; and (3) intravascular injections of 99mTcO4 into blood vessels underlying test points. Only the hypodermic injection of 99mTc into points of low electrical resistance gave rise to a specific radioactive pathway characterized by rapid and longitudinal migration, clearly independent of background activity. The specific radioactive pathway detected is not the result of diffusion of the radiotracer through nerves, veins or lymphatic vessels, but its trajectory coincides with that described for one of the acupuncture meridians in the dog.

Animals↗
PubMed1991

99Tcm-HMPAO leucocyte scintigraphy in the diagnosis of bone infection.

The utility of 99Tcm-HMPAO leucocytes has been studied in combination with 99Tcm-MDP bone scanning in the diagnosis of bone infection in a series of 50 patients with a clinical suspicion of bone infection. Thirty-three patients were referred to our Service from the Department of Orthopaedic Surgery (Group A) and seventeen from the Infectious Disease Unit (Group B). A total of 52 lesion sites were studied. The leucocyte and bone studies were performed within four days. The leucocyte scan was obtained at 30-60 min and 4-6 h after i.v. injection of 370 +/- 74 MBq of 99Tcm-HMPAO leucocytes. After confirming the scintigraphic findings, the results obtained were: Group A, 12 true positive, 21 true negative and 2 false positive; and in Group B, 5 true positive, 9 true negative and 4 false negative. The overall sensitivity was 80.9% with a specificity of 93.7%. Although the high bone marrow activity seen with 99Tcm-HMPAO leucocytes may reduce sensitivity, very good results were obtained in bone infection. The use of 99Tcm means great progress in the radiolabelling of white blood cells in terms of availability and better image quality. The combination of 99Tcm-HMPAO leucocytes and 99Tcm-MDP can be recommended as one of the most suitable methods for use in the diagnosis of bone infection, especially in patients with previous bone disease.

Adolescent↗
PubMed1991

Comparative study of the kinetics of the renal tracers 99Tcm-MAG3 and 131I-hippuran.

Serial measurements of plasma activity, plasma protein binding and urine excretion were obtained in order to study 99Tcm-MAG3 (MAG) and 131I-Hippuran (OIH) kinetics after simultaneous injection of both tracers in 21 patients with various renal diseases. Results were compared on the basis of a compartmental model, calculating the rate constants as well as the clearance and volume of distribution. Protein binding was calculated in 10 patients (mean: MAG = 54.7%, OIH = 33.8%). The dependence of time, tracer and patient factors was shown by ANOVA. Time was independent, with tracer and patient factors and their interaction being significant. The mean value of the renal excretion constant was equal for the two tracers (k12 = 0.052 min-1). The clearance values were found to be highly correlated (r = 0.982) with a ratio of 0.57 between them. The volumes of distribution in litres were 4.1 (MAG) and 7.0 (OIH). One-hour urine excretion was nearly the same for both tracers (MAG: 64%, OIH: 63% of the injected dose).

Blood Proteins↗
PubMed1991

Vertebral fractures in steroid dependent asthma and involutional osteoporosis: a comparative study.

BACKGROUND: Reduced bone mass predisposes patients to the development of vertebral fractures. Measurement of bone mass by non-invasive methods is used to detect patients with involutional osteoporosis at risk from fractures. These methods have not been assessed in patients with steroid dependent osteoporosis. The objective of this study was to assess the value of a predictive fracture threshold value of bone density in patients with steroid dependent asthma. METHODS: Three groups of patients were studied. Group 1 (67 patients) had steroid dependent asthma (mean daily dose of prednisone 11.7 mg) and no vertebral fractures, group 2 (32 patients) had steroid dependent asthma (mean daily dose of prednisone 12 mg) and vertebral fractures, and group 3 (55 patients) were not taking steroids but had involutional osteoporosis and a recent non-traumatic vertebral fracture. Bone mineral density was measured by dual photon absorptiometry and vertebral fractures by radiography of the lumbar spine. A fracture threshold was determined in the two groups with fractures as the 90th percentile of the mean bone mineral density measured in the lumbar spine. RESULTS: Bone mineral density was significantly higher in the steroid dependent group with fractures (group 2) than in group 3 patients, who had involutional osteoporosis and fractures (0.946 (0.18) g/cm2 v 0.830 (0.16) g/cm2). The fracture threshold value was therefore higher for patients with steroid related vertebral fractures (group 2, 1.173 g/cm2) than for those with involutional osteoporosis (group 3, 0.979 g/cm2). Vertebral fractures were more likely to occur in steroid dependent asthmatic patients with bone density above the fracture threshold value (obtained from subjects with involutional osteoporosis) than in subjects in group 3 (34% v 9%). CONCLUSION: Vertebral fractures occur in patients treated with steroids in the presence of higher bone mineral density than is the case with patients with involutional osteoporosis. The findings suggests that the assessment of the efficacy of preventive treatment requires measurement of bone mineral density and radiology.

Adult↗
PubMed1991

Intestinal calcium absorption and parathyroid hormone secretion in asthmatic patients on prolonged oral or inhaled steroid treatment.

A secondary hyperparathyroidism resulting from decreased intestinal calcium (Ca) absorption has been proposed as a contributory factor to glucocorticoid-induced osteoporosis. Inhaled steroids do not usually suppress adrenal gland function unless daily doses above 1,500 microgram are used. A recent study, however, has shown a reduced total body calcium in patients on regular beclomethasone treatment. In theory, osteopenia in these patients could be due to a direct effect of inhaled steroids on bone or due to an impaired intestinal calcium absorption. In this study, Ca absorption and parathyroid hormone (PTH) secretion were evaluated in three groups: 1) asthmatics on continuous oral and inhaled steroid treatment (11.3 +/- 4.4, range 5-33.5 mg.day-1 prednisone and 660 +/- 265, range 400-1,600 microgram.day-1 beclomethasone, respectively); 2) asthmatics on regular beclomethasone therapy (585 +/- 210, range 400-1,200 microgram.day-1); and 3) healthy subjects. The prevalence of vertebral fractures was evaluated by a spinal X-ray. No differences were found in either Ca absorption or PTH serum levels between asthmatics and healthy subjects (analysis of variance-ANOVA). Vertebral fractures were significantly more frequent in patients from group 1 (14 of 25) than in those from group 2 (2 or 25). We conclude that both prolonged oral steroid treatment and inhaled steroids, at doses lower than 1,600 microgram.day-1 do not cause Ca malabsorption, and that hyperparathyroidism does not contribute to osteoporosis in these patients.

Administration, Inhalation↗
PubMed1990

Treatment of steroid-induced osteopenia with calcitonin in corticosteroid-dependent asthma. A one-year follow-up study.

Sixty-two steroid-dependent asthmatics who had not received any form of treatment to prevent bone loss were studied during a 12-month period. Patients were randomly divided into two groups. Thirty-one patients were treated with 1 g of elemental calcium taken daily plus 100 IU of salmon calcitonin every other day, administered subcutaneously; the remaining 31 patients received only calcium supplementation. In the calcitonin group, 11 patients dropped out of the study because of severe side effects (seven patients), lack of compliance (three patients), and exacerbation of asthma (one patient). The 20 patients who completed the 12-month follow-up period were analyzed and compared with 20 sex-matched patients from the control group. At one year, bone mineral density (BMD) had increased in the calcitonin group by a mean of 4% (p less than or equal to 0.001), whereas in the control group BMD had decreased by 2.5% (p less than or equal to 0.05). Parameters of bone remodeling (alkaline phosphatase and osteocalcin) decreased significantly in the calcitonin-treated group but not in the control group. Our findings show that calcitonin 100 IU, given three times/wk, is an effective drug in the treatment of steroid-induced osteopenia. Side effects, however, are frequent and cause a high degree of dropout from therapy. These findings suggest that further studies should be carried out with lower doses of calcitonin or by other better tolerated forms of delivery such as in a nasal spray.

Asthma↗
PubMed1988

Abnormal scintigraphic evolution in AA hepatic amyloidosis.

A patient with AA amyloidosis secondary to ankylosing spondylitis showed intense liver uptake of Tc-99m MDP on bone imaging. The biopsy showed hepatic amyloid deposition. A repeat bone scan with Tc-99m MDP 1 year later was negative, although the clinical signs and liver function tests of the patient had not changed. A mechanism might exist, other than the affinity of amyloid to calcium, which would explain the extraosseous uptake of pyrophosphates and diphosphonates in organs and soft tissues affected by systemic amyloidosis.

Amyloidosis↗
PubMed1988

Uptake of technetium-99m DISIDA by bone metastasis from a hepatoma.

Uptake of Tc-99m DISIDA in a bone metastasis from a hepatoma located at the humeral head is reported. Previous literature has only shown extrahepatic uptake of hepatobiliary agents in cases of lung metastases from hepatocellular carcinoma. The use of imaging with biliary tracers can increase the diagnostic specificity when bone metastases from hepatoma are suspected.

Bone Neoplasms↗
PubMed1987

False-positive early indium-111 leukocyte scan.

An In-111 leukocyte scan was performed in a cirrhotic patient with ascitic fluid infection to rule out an abdominal abscess. Scintigraphy showed localized uptake in the area between the liver and right lung 30 minutes after reinjection of the labeled cells. The 24-hour study was negative. No purulent collection was demonstrated in any location.

False Positive Reactions↗