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Biomedical subjects

H W Pabst

Publications and source records attributed to H W Pabst.

At least 73 records · Page 4Linked to original sources
PubMed1979

[Unilateral pulmonary artery aplasia with special reference to lung scintigraphy (author's transl)].

In a case of unilateral aplasia of one Arteria pulmonalis, i.e. proximal interruption, the diagnostic value of perfusion and ventilation scintigraphy is shown to be simple and non-invasive, exposing the patient to a lower radiation dose than other diagnostic screening methods. When an interruption of a main pulmonary artery is radiologically suspected the scintigraphic examination allows to distinguish between vascular and/or parenchymatous pulmonary diseases, thus clarifying the diagnosis of primary pulmonary malperfusion. The results of other examinations, the relevant literature, the pathogenesis and pathophysiology of unilateral pulmonary artery aplasia as well as therapeutical and prognostic aspects are reviewed.

Adolescent↗
PubMed1978

[Noninvasive assessment of left ventricular dynamics (author's transl)].

ECG triggered scintiphotography has established itself as a reliable, reproducible, noninvasive method for the determination of ventricular volumes, left ventricular ejection fraction, and regional ventricular wall motion. It can be used with sufficient precision and accuracy in severely ill patients who are not suitable for invasive diagnostic procedures. The method is useful for follow-up investigations of known heart disease. In comparison with left ventricular cineangiocardiography a correlation coefficient of r=0.78 could be found for enddiastolic voluumes, of r=0.92 for endystolic volumes, and of r=0.91 for ejection fraction. The sensitivity of the method for recognition of disturbances of regional ventricular wall motion is 94%, the specificity 86%. In comparison with left ventricular cineangiocardiography the resulting accuracy is 90%.

Adult↗
PubMed1978

[Scintigraphy and fine needle biopsy in nodular goiter. Results in 548 patients].

The results of scintigraphic and cytological investigations in 548 patients with goiter are presented: In 402 goiters 470 nodes were detected, 385 of which were scintigraphically "cold". 276 solitary nodules were found, 109 in cases of multinodular goiter. Solitary nodules were preferentially located in the right lobe. The cytological diagnosis was confirmed histologically in 88 cases. Out of 24 malignant tumors, 21 were diagnosed correctly by means of cytology. The positive smears and the histological findings were in agreement in 14 of 15 cases. The accuracy of cytological diagnosis in the detection of thyroid malignancies was 87.5%. 12.5% of the smears were false negatives, 1.6% false positives and 10.9% false suspicious. The relative high percentage of false suspicious smears is caused by difficulties in cytologic differentiation of thyroid lesions due to microfollicular structures which are usually only classified as "follicular neoplasia". This cytologic term necessitates an obligatory histologic examination since cytology does not allow to differentiate between follicular adenomas and carcinomas. 5.5% of the histologically ascertained cold nodules were malignant, in 19% of the cases with cold nodes thyroid punction revealed cystic lesions.

Biopsy, Needle↗
PubMed1978

[Radioimmuno-assay of TSH before and after TRH in 350 patients with previous resection of euthyroid goiter (author's transl)].

Radioimmuno-Assay (RIA) of Thyroid-Stimulating-Hormone (TSH) was performed before and after i.v.-injection of Thyrotropin-Releasing-Hormone (TRH) in 350 patients subsequent to previous resection of euthyroid goiter to find out the optimal treatment schedule for preventing recurrent goiter. In patients without recurrent goiter the dosis of thyroid hormone was considered to be sufficient, if the difference in TSH-levels before and after TRH (delta-TSH) was equivalent to or less than 10 microunits/ml. In patients with recurrent goiter the optimal suppressive dosis of thyroid hormone was accepted for a delta-TSH less than or equal to 2,5 microunits/ml. 126 out of 135 patients, who were set on an immediate and continuous postoperative treatment were free of goiter, 58 presented a delta-TSH less than or equal to 10 microunits/ml (average interval of treatment = 2,5 years), 68 patients had elevated delta-TSH (average interval of treatment 2,1 years) as a sign of insufficient treatment. In 9 patients recurrent goiter was detected in spite of "adequate" treatment. 41 out of 57 patients, set on delayed and partly continuous, partly discontinuous treatment had recurrent goiter (in average after 10 years). delta-TSH was not indicative. 158 patients without any treatment had borderline or slightly increased delta-TSH (in average after 10 years). 122 of these 158 patients had recurrent goiter, 36 were free of goiter. The results favor the necessity of treatment with thyroid hormones starting immediately after operation and with continuous treatment. The combined use of TSH-RIA and TRH-test reliably informs about the individual thyroid hormone dosis necessary for prevention or treatment of recurrent goiters.

Goiter↗
PubMed1978

[Non-invasive nuclear medical diagnosis in cardiology. 201T1-myocardial and ECG triggered heart ventricle scintigraphy].

201Thallium scintigraphy serves as a non-invasive method for visualizing regional perfusion, viability and configuration of the myocardium. Serial scans performed after injection during ergometric exercise allow to differentiate between irreversible cell damage, i.e. myocardial infarction or scar, and transient, reversible ischemia in patients with coronary heart disease. ECG-gated blood pool scans are an ideal adjunct as they represent the functional results of the pathologically altered myocardium. This method permits quantitative determination of the enddiastolic volume, endsystolic volume and left ventricular ejection fraction. Furthermore, regional and global wall motion may be judged qualitatively. Results of both methods show an excellent correlation with those obtained by invasive catheterization and cineangiocardiography. The clinical value is based on screening and follow up of a broad variety of cardiac diseases.

Electrocardiography↗
PubMed1978

Determination of total, divided and regional tubular clearance and excretion by compartmental analysis of camera renograms.

A method to analyze the camera renogram is described in a mathematical manner. It is based on a 6-compartment model, which simulates the hippurate in vivo kinetics. Results are transfer rate constants from which the tubular clearance (by multiplying with the plasma volume) and additionally excretory parameters can be derived. The method is quick and simple and needs a gamma-camera and a small data processing system only, but no special equipment and no blood sampling.

Computers↗
PubMed1978

Comparison of different methods of clearance determination.

Clearance determination by compartmental analysis of hippurate renograms was compared in 30 cases to the conventional PAH and to the partly shielded whole body counting technique. Good correlations between compartmental analysis and PAH method (r = 0.96) as well as the whole body technique (r = 0.94) were found. Correlation between PAH and whole body method was not always satisfactory (r = 0.85). In an additional study influence of greater count rates become obvious: correlation coefficients increase from 0.89 (131I-hippurate, n = 97) to 0.95 (123I-hippurate, n = 38). Determination of the divided clearance correlates well (r = 0.95). Using 123I-hippurate all the information available by radioisotopic kidney investigations can be obtained in a one-step procedure.

Aminohippuric Acids↗
PubMed1978

Serial bone scintigraphy for assessing the effectiveness of treatment of osseous metastases from prostatic cancer.

130 serial bone scintigrams were performed to evaluate the course of skeletal metastases under treatment in 36 patients with prostatic cancer. During a successful treatment scintigraphic controls revealed a significant decrease of the metastatic 99mTc-diphosphonate uptake in 14 patients and sometimes even a complete normalization of the skeletal radioactivity distribution, whereas a progression characterized by an increased multifocal radioactivity concentration was registered in 16 patients indicating the failure of the initiated therapy. Based on these results of follow-up studies scintigraphic bone imaging can be recommended for the assessment of the effectiveness of on-going therapy of skeletal metastases.

Bone Neoplasms↗
PubMed1978

[Scintigraphic and experimental studies with 67Ga in 142 patients with bronchial cancer (author's transl)].

In 142 patients with untreated bronchial carcinoma positive 67Ga scintigrams were obtained in 132 cases (93%). 6 of 10 scintigraphically not detected tumors had diameters less than 2 cm, 4 carcinomas presumably consisted of necrotic tumor masses. There was no dependence of 67Ga accumulation on the histomorphological type of tumor. Differentiated and undifferentiated carcinomas showed a comparably high 67Ga uptake. These scintigraphic findings were confirmed by measuring the quantitative 67Ga concentration in 132 tissue samples of various tumors. In addition these studies revealed an absent or decreased 67Ga accumulation in more or less necrotic tumor masses. The positive tumor scintigraphy with 67Ga-citrate as a non-invasive method is suitable for detecting untreated bronchial carcinomas, especially those localized in the hilar or mediastinal region, which cannot be visualized roentgenologically as well as for indicating the effectiveness of radio- or chemotherapy. 67Ga scanning is also useful in establishing the reappearance of viable tumor tissue in follow-up studies of tumor diseases. The use of 67Ga as a tumor-seeking scanning agent is limited because of its lack of tumor specifity and of its inability to detect tumors smaller than 2 cm in diameter.

Bronchial Neoplasms↗
PubMed1978

[Evaluation by means of ECG-gated cardiac blood pool scintigraphy of global and regional left ventricular function at rest and during exercise in patients with coronary artery disease (author's transl)].

ECG-gated cardiac blood pool scintigraphy permits a non-invasive determination of the end-diastolic and end-systolic ventricular volumes and of the ejection fraction as well as a qualitative description of regional ventricular wall motion at rest and during excercise. In 6 healthy persons a significant increase of the ejection fraction from 66 +/- 7% at rest to 78 +/- 3% during exercise (p less than 0.01) was observed. In contrast, the ejection fraction decreased in 15 out of 18 patients with coronary artery disease, with a significant (p less than 0.01) difference between patients with and without angina pectoris. Thus, the ejection fraction fell in 12 patients without angina during excercise from 60 +/- 11% to 52 +/- 11% (p less than 0.05) whereas in 6 patients with angina a decrease from 61 +/- 7% to 30 +/- 8% (p less than 0.01) was observed. This non-invasive technique makes it possible to demonstrate in a simple and safe manner changes of cardiac function during excercise in patients with coronary artery disease.

Adolescent↗
PubMed1977

Detection and differential diagnosis of bone lesions by scintigraphy.

Bone scintigraphy using 99mTc-labeled phosphate compounds and the scintillation camera supplements X-ray diagnosis in an excellent manner, for localizing and determing the size and metabolic activity of inflammations, degenerations, and malignancies of the skeletal system. It is of prime importance in the early detection and staging of the disease, as well as in registering the course and response to therapy of osseous metastases.

Bone Neoplasms↗
PubMed1977

[Quantitative assessment of drug-induced prophylaxis of postoperative thromboembolism. Comparison of frequencies of deep vein thrombosis and pulmonary embolism using acetylsalicylic-acid, dextran, dihydroergotamine, low-dose heparin and the fixed combination of heparin and dihydroergotamine (author's transl)].

2136 patients in general surgery, gynaecology and urology were investigated by the 125I-fibrinogen-uptake-test for detection of postoperative deep vein thrombosis (DVT). They received at random one of low-dose heparin, dihydroergotamine, the fixed combination of both drugs (Heparin-Dihydergot), low molecular weight dextran and acetylsalicylic-acid (ASS). When DVT was detected repeated lung perfusion scintigraphies were carried out for diagnosis of embolic pulmonary perfusion defects. Results demonstrate the outstanding effect of Heparin-Dihydergot, which is not only 2-3 times better than the anti-thrombotic standard low-dose heparin but also eliminates almost completely the risk of postoperative embolism. The preventive efficacy of ASS and dextran must be considered to be poor and not comparable to that obtained when using heparin, dihydroergotamine or the combination. Now Heparin-Dihydergot is the new standard with which all prophylactic procedures should be compared.

Adult↗
PubMed1977

[Diagnosis of skeletal metastases in prostatic cancer using gamma camera (author's transl)].

On 170 patients with histologically proven carcinoma of the prostate scintigraphic studies of the skeleton using gamma camera and follow-up examinations were performed and compared with x-ray as well as serum alkaline and acid phosphatase. Osseous metastases in 47% had no radiological evidence and were only scintigraphically detectable. Positive scans were registered in 48% of the patients with prostatic cancer, 20% of them were positive due to metastases and 28% were false positive caused by osteoarthrotic and arthritic changes, sporadically by post-traumatic lesions and in 3 cases by Paget's disease. At the time of the initial diagnosis of prostatic cancer 21% of 159 patients studied scintigraphically had radiological or scan evidence of osseous metastases. Analyses corresponding stages of tumor revealed an unequivocal dependance of the frequency of metastases upon the extent of the primary tumor. The successful treatment is characterized by the decreased uptake of radioactivity primarily accumulated in skeletal metastases.

Aged↗
PubMed1977

[Possibilities for nuclear medical investigation in the retroperitoneal space: (author's transl)].

The possibilities for nuclear medical investigation in the retroperitoneal space were extended by the introduction of the scintillation camera with an evaluation system. The diagnostic aid in diseases of the kidney (unilateral and bilateral nephropathies, shock kidney, stenosis of the renal arteries, aortic occlusion), suprarenals (Conn syndrome) and the skeleton of the entire body (diagnosis of metastases and non-malignant bone diseases) are reviewed. Scanning scintigraphy can be used in the identification of lymphnode metastases in negative (198 Au colloid) and positive (67 Ga) tumor contrast and in double radionuclide substraction techniques in pancreatic tumor and chronic pancreatitis. Clinical examples are demonstrated.

Adrenal Gland Diseases↗
PubMed1977

[Simultaneous determination of kidney glomerular and tubular partial functions with 99mTc-DTPA and 131I-hippuran using a partially shielded whole body counter].

The methodical prerequisitis and the clinical results-of simultaneous double-radionuclide determinations of renal clearances of 99mTc-DTPA (Sn) and 131I-Hippuran, using a partially shielded whole-body counter, are reported. Examination of the in vitro stability of the 99mTc-DTPA (Sn) complex by radiochromatographic separation revealed an unbound 99mTc fraction of 4.7%. The whole body measurement geometry was found over the non-shielded regions of the body to be independent of the various physiological distribution volumes of the clearance substances. The simultaneously determined clearances of 51Cr-EDTA and 99mTc-DTPA resulted in a strong linear correlation (r = 0.96; n = 20). The relation between serum creatinine concentration and 99mTc-DTPA clearance was approximately hyperbolic (r = 0.89; n = 154). In a group of normals (n = 102) the renal filtration fraction (FF - ClTc-DTPA/ClOIH) was 0.18 +/- 0.04. In a group of urological patients (n = 72) this fraction did not change appreciably before and after operations, whereas it was found increased to 0.25 and 0.24, respectively, in patients with diabetes and albuminuria or urinary tract infection (n = 37). The relative error of the clearance determination with a partially shielded whole-body counter was about 15% down to clearances of some 50 ml/min, and higher than 50% with clearances below 20 ml/min.

Albuminuria↗
PubMed1976

Prevention of postoperative thromboembolism by various treatments. Controlled clinical trial in 632 patients using 125I-fibrinogen uptake test and lung perfusion scans in patients with deep venous thrombosis.

In 632 patients efficacy of dihydroergotamine (DHE) in preventing postoperative deep venous thrombosis (DVT) and pulmonary embolism (PE) was tested vs. low-dose heparin (LDH) by means of the 125I-fibrinogen uptake test (RFUT). The incidence rate of DVT dropped from 36% (untreated group) to 17% after LDH, to 13% after DHE, and to 9% after simultaneous prophylaxis with both drugs. In patients with lower risk operations lasting not longer than 2 hs complete prevention of DVT was achieved by combined use of LDH and DHE. PE incidence in repeated lung perfusion scans of patients with positive RFUT was reduced to 4.3-2.6% (treated groups) in comparison to an incidence of 50% in the control group. This means the decrease of PE was overproportional in all treatment groups in comparison to the decrease of DVT incidence. The combined use of LDH and DHE may be considered as the best prophylactic regimen available for lowering postoperative DVT and PE.

Clinical Trials as Topic↗