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Biomedical subjects

B Leisner

Publications and source records attributed to B Leisner.

50 records · Page 3Linked to original sources
PubMed1979

[Determination of the iodine content of the thyroid by means of fluorescence scans (author's transl)].

A procedure is described in which stable 127I in the thyroid is induced to fluorescence (28.5 keV) by 241Am (59.5 keV). The radiation is registered on a Si (Li) detector and can be used in order to obtain a scintigram or to determine the concentration of127I in the thyroid at any selected point. The apparatus is available commercially and has been adapted for use with a scanner. Measurements using collimation of 3.5 to 4 cm revealed a focus with a marked tomographic effect. The sensitivity of the apparatus was investigated by using solutions of varying iodine concentrations; calibration curves for determining iodine concentration in thyroid tissue were obtained. It is necessary to take account of the thickness of the thyroid gland and of the superficial tissues because of the marked attenuation of the radiation within the tissues. Radiation dose to the thyroid during the scintigram was about 0.1 mGy (10 mrd), i.e. about 5% of a conventional TC scintigram. There is no whole body irradiation.

Humans↗
PubMed1979

[Clinical result of thyroid scintigraphy and iodine estimations using a fluorescent technique (author's transl)].

The new technique of quantitative fluorescent scintigraphy was used for determining the regional distribution and concentration of stable intrathyroid iodine (127 I) in 96 patients. Average iodine concentration in normal people (20 individuals) without thyroid enlargement living in the Bavarian iodine-deficiency area was 0.38 +/- 0.07 mg/g. In 32 patients with simple goitres it was significantly lower at 0.17 +/- 0.06 mg/g. With this technique it was possible to separate two types of hyperthyroidism amongst 21 patients: those with low iodine concentration in the thyroid (0.15 +/- 0.08 mg/g) and those with high iodine concentration (0.42 +/- 0.12 mg/g) after iodine administration. The iodine concentration in decompensated autonomous adenomas in twelve patients was usually low (0.12 +/- 0.12 mg/g). On the other hand iodine concentration was high in the paranodular tissues and could be demonstrated on the fluorescent scintigram. The quality of the scintigram using this technique for concentrations below 0.1 mg/g is inadequate. In this situation good imates can be obtained by radionucleid scintgrams. The situation is reversed by previous administration of iodine.

Diagnosis, Differential↗
PubMed1979

[Correction of unilateral 131I-hippuran clearance by sonographic evaluation of kidney depth (author's transl)].

In 47 patients the value of kidney depth measurements for the correction of unilateral 131-I-hippuran clearances was studied using ultrasonography. The accuracy of this method was found to be superior to that of the lateral scintigram. In cases with normal cranio-caudal position or slight unilateral caudal dystopia the maximum difference in kidney depth was 1.25 cm and a maximum correction of the unilateral clearance in 2.8% was necessary. Kidneys with unilateral caudal dystopia differed up to 6 cm in depth, leading to a correction by 12%. Our findings indicate that a correction for kidney depth is necessary if one kidney shows significant caudal dystopia and slight dystopia in the supine position. In patients with nephroptosis position-dependent alterations of unilateral perfusion can only be evaluated by correcting for kidney depth.

Adult↗
PubMed1979

[Comparative studies of radioisotope uroflowmetry (author's transl)].

Radioisotope uroflowmetry allows continuous recording of urinary stream with determination of maximum and mean urine flow rate, duration of voiding and residual urine without urethral catheterisation. By the aid of twenty simulated tests and nine examinated patients the precision of this method was investigated by comparing our results with the findings of simultaneously recorded mictiographic measurement. The flow curves and the maximum flow rate show a high correlation.

Humans↗
PubMed1978

[The application of a radionuclide technique for uroflowmetry and determination of residual urine in gynecology (author's transl)].

The micturition of 74 female patients with different disturbances of bladder voiding was studied using 99mTc-DTPA and a gamma camera connected to a cinescintigraphic system and a small computer. The urinary flow and the residual urine were determined from the voided urine volume and from the time-activity curves and the residual counting rate respectively recorded over the bladder region. The values of normals are compared with those found in different types of incontinence and neurogenic micturition disorders. The method provides important parameters of the dynamics of bladder voiding without unphysiologic manipulations. The costs are very low if the standard equipment of a nuclear medicine department can be used.

Female↗
PubMed1978

[Preoperative and postoperative stomach evacuation studies via methods of nuclear medicine and methods of roentgen cineradiography (author's transl)].

A combination of roentgen cineradiography and functional scintigraphy of stomach evacuation, taken with a gamma camera, was used for assessing the success of organ-conservative surgery of ulcers (selective proximal phagotomy with or without pyloroplasty). This confirmed earlier results to the effect that surgical failure is not indicated with any measure of certainty by any individual roentgenologic symptom. However, the evacuation function is closely correlated with the pattern of clinical and subjective complaints. In most of the cases, rapid postoperative stomach evacuation results in freedom from complaints. Pyloric stenosis and retention point to the failure of the operation via the negatively effected subjective feeling of well-being. Hence, special importance must be attached to functional scintigraphy with regard to meaningful studies of the course and postoperative condition of the patient.

Gastric Emptying↗
PubMed1978

[Xeroradiography in the diagnosis of skeletal diseases (author's transl)].

The value of xeroradiography in the diagnosis of peripheral skeletal lesions is illustrated by some typical examples and compared with standard radiographic procedures. The advantages of xeroradiography depend on its convenient format, easy appreciation of structural changes and easy viewing. On the other hand, density gradations are flattened. Compared with a technically satisfactory film examination, there is no increase in diagnostic information. Xeroradiography can therefore only be regarded as complementary to conventional radiography for the diagnosis of skeletal conditions.

Bone Diseases↗
PubMed1978

[Functional scintigraphy in the diagnosis of gastroesophageal reflux (author's transl)].

The accepted diagnostical procedures to prove a gastroesophageal reflux by direct or indirect methods do not allow any quantification and are of limited sensitivity. A quantification is possible by use of a gamma-camera with a computer-system after application of a small amount of 99m Tc-DPTA (reflux scintiscan). The high accuracy of this method could be proven by evaluation of 51 patients with suspected gastroesophageal reflux esophagitis or after total gastrectomy. The results were compared with the histological findings. With this method we found after total gastrectomy the expected high incidence of relux. The long-term results after semifundoplication were not as good as after fundoplication. The reflux scintiscan is a less invasive, but reliable method to detect the gastroesophageal reflux.

Gastroesophageal Reflux↗
PubMed1975

[Concentration of 99mTc-tin-phosphate complexes in soft tissues].

The concentration of 99mTc-pyrophosphate was determined in the lower extremities of rabbits (normal, abacterial and bacterial affected soft tissues), in osteoarthritis of the hip joint (capsule and muscle) as well as in knee joint effusions. Compared with the 85Sr-concentration, reflecting the calcification capacity, concentrations of 99mTc-pyrophosphate in soft tissues were found to be lower 2 hours p.i., but were up to elevenfold higher 24 hours p.i. These findings should be due to a fixation of 99mTc-pyrophosphate in collagen containing tissues as in the soft tissue tumors (myosarcoma, synvialioma, breast cancer) presented. A mechanism of delayed equilibration could explain augmented uptake in lymph-edema, ascites and effusions in florid osteoarthritis of the knee joint. The possible dependence of 99mTc-pyrophosphate concentration in bone and soft tissue on collagenous contents is discussed.

Animals↗
PubMed1975

[Determination of 131-J-hippuran clearance in renal camera functional scintigraphy using simplified Oberhausen's method].

The determination of 131-I-Hippuran clearance in connection with renography or renal camera sequential scintigraphy will give a quantitative evaluation of total and individual renal function. The "single shot" method of Oberhausen yields clearance values corresponding very well to the PAH standard clearance. To simplify this method for routine use in connection with camera sequential scintigraphy, we studied some modifications of the method, using regional activity curves instead of the activity curve of the partially shielded whole body. Simultaneously with the camera sequential scintigraphy we measured activity curves of the partially shielded whole body (lead-shielding of kidneys and bladder, two probes), the shoulder (one probe), the head (one probe) and a background region of the camera (ROI) above the kidneys for 30 min. All four curves were analyzed, using computer analysis (bi-exponential curve fitting) as well as tables of Oberhausen, and his formula was used for clearance calculation. Under two conditions a) taking blood samples between 15 and 25 min. p.i. b) using the tables of Oberhausen for curve analysis, the clearance out of the regional activity curves correlates well with the clearance out of the partially shielded whole body activity curve (r greater than 0,97). Therefore, it is possible determine 131-I-Hippuran clearance in a simple manner without lead-shielding of kidneys and bladder, either with one additional probe measurement at shoulder or head or without any probe measurement, using the camera and measuring a background curve (ROI) above the kidneys. This simple clearance method can easily be performed simultaneously with 131-I-Hippuran renography or renal camera sequential scintigraphy in routine.

Head↗
PubMedDate not supplied

Iodine contamination as a cause of hyperthyroidism or lack of TSH response to TRH stimulation (results based on a screening investigation).

The sera of all patients with completely suppressed TSH response to TRH obtained during one year (n = 668), and of those with diminished TSH response (n = 153) were screened for total serum iodine content. The ratio between serum iodine and thyroxine iodine below 1.5 indicates none or only a minor degree of iodine contamination, whereas a ratio above 1.5 is a clear index of exogenous iodine contamination. Eighty-four (21.3%) of 395 patients with overt hyperthyroidism were iodine contaminated. No prevalence of hyperthyroidism with hyperthyroxinemia could be detected as compared to T3-hyperthyroidism in the contaminated groups. Surprisingly, the iodine contamination rate was twice as high in 273 patients with suppressed TSH response to TRH but normal thyroid hormone levels and not fully explained thyroidal diseases. A high incidence of multifocal autonomous adenomas of the thyroid is the most probable explanation for the TSH suppression in iodine contaminated patients with normal thyroid hormone levels.

Angiocardiography↗