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Biomedical subjects

A Mostbeck

Publications and source records attributed to A Mostbeck.

At least 19 recordsLinked to original sources
PubMed1992

Frequency of pulmonary embolism in ambulant patients with pelvic vein thrombosis: a prospective study.

One hundred thirty-nine consecutive patients (average age 70.1 years) who were able to walk with a swollen leg were seen at the clinic where diagnosis of acute deep vein thrombosis (DVT) extending to the pelvis was confirmed by injecting microspheres labeled with technetium 99m into the dorsal foot vein (radionuclide venography). Thirty-nine (28%) of these patients had malignant disease. Perfusion lung scans performed immediately after radionuclide venography were supplemented by inhalation scans (99mTc-labeled diethylenetriamine pentaacetic acid aerosol) in case of perfusion defects. During scintigraphy patterns highly indicative of pulmonary embolism (PE) were found in 80 patients (58%), but only 11 (7.9%) had minor clinical symptoms. All patients were admitted to the ward, were given standard heparin subcutaneously (35,000 to 40,000 units/24 hr) and firm bandages, and were encouraged to walk. After 11 days pulmonary scintigraphy was repeated and revealed no change in 55 of 59 patients without PE and in 40 of 80 patients with PE. Thirty-three patients (23.7%) showed regression of perfusion defects. New PE developed in 11 patients (7.9%, four without and seven with previous PE). Autopsy revealed that one 80-year-old patient with prostatic carcinoma had died of massive PE. When comparing this frequency of newly developed PE during ambulation with the occurrence of PE after bed rest, according to the literature, it is no more dangerous for a mobile patient with proximal DVT to walk wearing a firm bandage than it is for the patient to be in bed. Therefore we recommend treating mobile patients with DVT by use of anticoagulation and firm compression bandages and without immobilization.

Adolescent↗
PubMed1991

[Recommendations for carrying out nuclear medicine kidney function tests with a gamma camera and computer].

Standardization of nuclear medicine renal studies is required in order to permit the comparison of study results of a patient obtained at different laboratories. Furthermore, standardization is a prerequisite for quality control of the analysis part of the procedure. The guidelines presented here are based on a survey carried out amongst nuclear medicine laboratories in Austria and have been edited and harmonized in a workshop organized by the Austrian Nuclear Medicine Society. The guidelines include detailed descriptions of the requirements of instrumentation, of the methods of acquisition, dosage and radiation dose of the commonly used radiopharmaceuticals and all aspects of the analysis of digital renograms. A comprehensive section deals with the determination of renal clearance from the renogram, further sections cover the usage and recommended methods of captopril renography for the diagnosis of unilateral renal artery stenosis and of the frusemide renogram for the diagnosis of nephropathy and uropathy.

Austria↗
PubMed1990

Urine excretion of inhaled technetium-99m-DTPA: an alternative method to assess lung epithelial transport.

Technetium-99m DTPA clearance (99mTc-DTPA) clearance measured by a gamma camera or a scintillation probe not only reflects epithelial transport, but is also influenced by an unknown amount of mucociliary clearance depending on particle size and aerosol deposition. This is confirmed by factor analysis of dynamic inhalation studies. Assessment of epithelial absorption by urinary excretion of inhaled 99mTc-DTPA is largely independent of aerosol lung deposition. Twenty-four-hour excretion reflects the amount of aerosol cleared by absorption, while two-hour excretion is a quantitative measure of the aerosol absorption rate from the epithelium into blood. Urinary 99mTc-DTPA excretion of two aerosols with different particle size correlated significantly (p less than 0.001) with analysis of lung clearance curves. A very similar regression in the form of a cumulative exponential function was found with both aerosols. Two-hour urine values of nonsmokers differed significantly from those of smokers or patients with active interstitial or infectious lung disease. This alternative procedure is suited as a bedside test and holds promise for patient monitoring and follow-up.

Administration, Inhalation↗
PubMed1988

[Measurements of radiocesium incorporation in 250 deceased patients who died within a year following Chernobyl].

Two months after the nuclear accident of Chernobyl, postmortem measurement of radiocaesium (137 Cs and 134 Cs) were started in different organs to study incorporation, organ distribution, and kinetics. 250 corpses were examined between July 1986 to August 1987 in the Department of pathology, St. Pölten. Highest concentrations were found in skeletal muscles, with a median value of 2.3 pCi/g wet weight (80-90% of the total incorporated dose), followed by liver, lung, spleen, kidneys, thyroid gland, heart, blood and brain, with values between 0.8 and 1.3 pCi/g. No caesium was detectable in fatty tissue. During the observation period an increase in caesium concentration was observed in almost all organs. The concentration almost doubled within 10 months in skeletal muscles. Only the lung demonstrated a decrease in the radiocaesium concentration within the first months, which can be explained only by inhalation of radiocaesium. A statistically significantly higher caesium concentration in most organs was found in females as compared with males. A possible explanation is the known lower urinary caesium concentration in women. Statistically significant correlations were found between caesium concentration and nutritional status, presence of malignancy, and the most recent intravital serum creatinine value.

Accidents↗
PubMed1987

Incidence and clinical feature of pulmonary embolism in patients with deep vein thrombosis: a prospective study.

In 169 patients with suspected deep vein thrombosis (DVT), the incidence and clinical feature of pulmonary embolism (PE) was prospectively studied by means of noninvasive thrombosis tests (uptake tests, radionuclide venography) and combined ventilation (133Xe, 81mKr) and perfusion (99mTc microspheres) lung scanning. DVT was detected in 62% of patients (105/169). The incidence of PE in patients with confirmed DVT was 57% (60/105), a figure which is in excellent agreement with data from autopsy studies. Concerning the thrombotic source of emboli, the incidence of PE was 46% in patients with DVT confined to the calf but increased to 67% if the thigh, and to 77% if the pelvic veins were involved as well. Fifty-nine percent of PE were clinically silent, 19% had "minor signs", and 22% "major signs". The size of the perfusion defects correlated significantly with clinical symptoms. Only 23% of clinically symptomatic patients had a pathological chest X-ray. Incidence of both DVT and PE increased with advancing age, but in old patients the incidence of PE rose disproportionately.

Adult↗
PubMed1987

[Single-photon emission tomography (SPECT) using 123I-amphetamine in cerebral ischemic circulatory disorders].

The uptake of 123I-amphetamine (IMP) in brain mainly corresponds to regional perfusion. Distribution of IMP can be visualized in tomographic slices by single-photon emission computed tomography (SPECT). For better evaluation and comparison in follow-up studies, right/left ratios were computed and an asymmetry index calculated. The most sensitive asymmetry index was achieved by 120 average circumferential profiles. In 52 patients with stroke and 16 controls the respective sensitivities of IMP-SPECT, computed tomography (CT), static and dynamic brain scanning and angiography were evaluated. In patients with TIA and PRIND the IMP-SPECT had the highest sensitivity of all non-invasive methods. In patients with completed stroke, the sensitivity of IMP-SPECT was comparable with that of CT (90 vs. 93%). There was a significant correlation between the IMP asymmetry index and the clinical and social score (p less than 0.001). The IMP asymmetry index was significantly correlated to the size of the CT lesion (p less than 0.001). In most patients, the size of the IMP lesion was larger than that of CT. In a prospective study, 28 patients with completed stroke were examined. 14 patients underwent surgical treatment (6 endarterectomies, 5 EIA, 3 combined operations), 14 patients had medical treatment only. Both groups were reexamined after 10 and 6.5 months, respectively. In both groups, neither the IMP asymmetry index nor the size of the CT lesion were changed, but the clinical and social scores improved (p less than 0.01). The outcome in both groups was the same. A positive effect of surgery could not be demonstrated.

Amphetamines↗
PubMed1985

Dry aerosol of monodisperse millimicrospheres for ventilation imaging: production, delivery system, and clinical results in comparison with 81m-krypton and 127-xenon.

The production of monodisperse human albumin millimicrospheres (diameter less than 1 micron) and labeling with 99mTc is described. A system constructed to nebulize and deliver a dry aerosol yielded a lung delivery efficiency of approximately 25%. In 48 patients without and with varying degrees of chronic obstructive lung disease, quantitative comparison with 81mKr (penetration index, regional distribution of activity in the lungs) demonstrated similar penetration of the particles to the lung periphery (r = 0.89 and r = 0.94, respectively). Qualitative comparison with 81mKr or 127Xe showed complete or a high degree of diagnostic agreement in all but one patient. Semiquantitative scoring of hot spots as a substrate of local turbulent airflow showed a close inverse correlation (r = -0.82) with the forced expiratory volume in 1 s (FEV 1.0%), thus providing additional information about the severity of the airway obstruction. In 24 patients with suspected pulmonary embolism, complete agreement between aerosol and 81mKr images was found in all patients studied. For same-day ventilation/perfusion studies, labeling of the millimicrospheres with 111In yielded images of comparable quality to those obtained with the 99mTc-labeled aerosol.

Aerosols↗
PubMed1979

Value of additional lateral scans in renal scintigraphy.

Although it is common to perform scintigrams in multiple projections this technique has not yet been generally accepted for kidney scintigraphy. By performing additional lateral scans using an Anger camera and with patients sitting we found at least three advantages: 1. Better Visualisation of Kidney Lesions: 7 (13,5%) of 52 cases with lesions could be detected in lateral projection only, in all other cases we obtained better information concerning location and size of lesions. 2. Determination of Real Kidney Size: Of 62 patients with kidneys appearing reduced unilaterally in the dorsal projection, additional lateral recordings demonstrated that 24 (39%) seemed diminished because of tilting. 3. Better Interpretation of Renograms: Demonstration of different depths of kidneys facilitates interpretation of renograms with different peak heights. Additional lateral scans thus can provide--at least if dorsal recordings are inconclusive--further information.

Diagnosis, Differential↗
PubMed1978

[Influence of dihydroergotamine and leg compression on the blood volume in different regions of the body (author's transl)].

After intravenous injection of 99mTc labelled autologous erythrocytes the radioactivity of a definite body-region is proportional to the local blood volume. By whole body scintigraphy it is possible to assess simultaneous changes of blood volume in different interesting regions. By this method the influence of 1 mg dihydroergotamine i.v. was investigated in 10 patients and of compression of both legs by inflatable leg cuffs (Jobst) with pressures of 25 and 40 mmHg (3,3 and 5,3 kPa) in 7 patients. After dihydroergotamine statistically significant decreases of blood volume were found in the legs and arms and increases in the thorax and liver. Over the abdominal region there was a statistically not significant decrease of blood volume. After leg compression a statistically significant decrease of blood volume in the legs and an increase in thorax, liver and abdomen were found. The arms showed a statistically not significant blood volume increase. The blood volume diminishing effect of dihydroergotamine in the legs was 20,4% in average, of a leg compression (25 mmHg=3,3 kPa) 33,4%. Contrary to the general opinion a reduction of blood volume was also found in legs with severe varicosis. The diminution of blood volume is even more intense in such cases than in normal legs. The results after dihydroergotamine are explained by its well known constrictor effect on the capacitance vessels in the extremities.

Abdomen↗