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Biomedical subjects

W Börner

Publications and source records attributed to W Börner.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Peripheral quantitative computed tomography for bone mineral measurement using a new special QCT-scanner. Methodology, normal values, comparison with manifest osteoporosis].

Some years ago we designed a special purpose gamma-ray QCT scanner for bone mineral measurements at the forearm. Currently, the first commercially built scanners (Stratec SCT 900) are being tested and clinically evaluated. The scanner uses an 125I photon source with a multidetector translate rotate fan beam geometry and newly developed semiconductor crystals. Quantification of trabecular bone and total bone at a standardized radial cross section gives an in-vivo reproducibility of less than 1%, which is superior compared to all other bone mineral measurement techniques. In-vitro reproducibility is between 0.2 and 0.4%, measured with calibration phantoms. The high in vivo reproducibility is ensured by automatic contour finding algorithms to determine the bone mass within a forearm cross sectional slice. A number of healthy men (n = 201) and women (n = 400) were examined to obtain a reference population for comparison to patients with generalized bone disease. We compared 182 osteoporotic females with healthy subjects. The high precision of the device and the high sensitivity of the measurement site considering changes of trabecular bone mass provide a very powerful means for monitoring bone mineral loss or changes due to therapy, as well as high diagnostic sensitivity.

Adult↗
PubMed1989

Tc-99m-HMPAO labelled human platelets: in vitro and in vivo results.

The lipophilic 99mTc-HMPAO complex can be used for labelling platelets as well as granulocytes. Platelets were isolated according to standard isolation procedures for the evaluation of the optimal labelling parameters. The labelling efficiency (%) depends on incubation temperature (22 degrees C: 40%: 37 degrees C: 50%), incubation time (3 min: 20%, 25 min: 55%) and the incubation medium (plasma: 40%; saline 50%). The 60 min 99mTc elution out of the platelets ranged around 8%. The platelet recovery used as a quality control parameter is around 25% +/- 4% and is stable for at least 240 min. The high elution rate out of the platelets leads to renal excretion of the label and hence to significant kidney and bladder activity. Intestinal excretion of the label can also be frequently demonstrated. Fresh thrombotic lesions can normally be detected 4 h after reinjection of the labelled platelets, and in some patients as early as 1 h after reinjection. In conclusion, 99mTc-HMPAO seems to be a promising platelet label for imaging thrombotic lesions but not for platelet survival studies, because of the short physical half life of 99mTc.

Blood Platelets↗
PubMed1989

Kinetic data of in-vivo labeled granulocytes in humans with a murine Tc-99m-labelled monoclonal antibody.

Twenty-five patients were examined in vivo with 99mTc labelled monoclonal antibodies; 15 with suspected infections with an antigranulocyte antibody (BW 250/183), 10 with suspected recurrence of a colorectal carcinoma with an anti CEA antibody (BW 431/26). Both antibodies were IgG1 isotypes. In the patients with suspected infections no change of the peripheral leukocyte count could be observed after the antibody injection (1 mg, n = 9; 0.5 mg, n = 1; 0.25 mg, n = 6). In 2 patients examined with the anti CEA antibody (2 mg), a significant decrease of the peripheral leukocyte count could be observed. The recovery rate of the 99mTc antibody labelled granulocytes was calculated to be about 10%. The increase of the antibody-antigen binding was calculated to be 0.2%/min. In vivo the organ distribution curves demonstrated an increase of 99mTc activity over spleen and bone marrow of 1.1%/min, which was interpreted as antigen-antibody reactivity. The organ distribution curves of the anti granulocyte antibody over spleen and bone marrow showed typical binding characteristics to the local granulocyte epitopes. The curves over other organs showed a simple perfusion pattern. The curves of the anti CEA antibody showed a perfusion pattern over all the examined organs. A sham dialysis model in one patient with renal insufficiency undergoing regular dialysis treatment demonstrated the viability of 99mTc antibody labelled granulocytes in vivo. The kinetic patterns of the 99mTc antibody in patients with Crohn's disease were interpreted as CEA binding of the antibody in the bowel wall.

Animals↗
PubMed1989

[Initial experiences with hysterosalpingoscintigraphy in normal and pathologic fallopian tube passage].

A prospective study in 38 patients was designed to evaluate the efficacy and reliability of radionuclide hysterosalpingoscintigraphy (HSS) using 99mTc labelled human albumin macroaggregates (HAMA). Following application in the posterior vaginal fornix at the time of ovulation, HAMA normally migrate spontaneously through the uterus and tubes and may be identified after 20 min (range 5-90 min) in the uterine cavity and after 2 hrs (range 40 min - 3 hrs) in the free pelvis, using a gamma camera. When correlated with the findings of conventional contrast hysterosalpingography (HSG), the radionuclide procedure yielded comparable results in females with patent or clearly obstructed tubes. Using 8-10 MBq 99mTc, radiation exposure was estimated to be 0.75 cGy per ovary, which is considerably less than the mean dose absorbed with HSG. As the HSS procedure imitates the migration of spermatozoa by the means of an inert tracer, it allows a direct insight in the mechanisms of passive transport taking place in the uterus and tubes at the period of ovulation. Thus, it reflects the physiological state of the female reproductive tract. On the basis of the scintigraphic findings, equivocal results on HSG have to be re-evaluated, as tubes, which are anatomically patent under high pressure, may be functionally deficient.

Adult↗
PubMed1989

[The importance of quantitative grey-scale analysis of the sonogram in "diffuse" thyroid diseases].

A sonographic grey scale (gs) analysis of the thyroid gland was retrospectively (1985-1986) performed in 248 patients with normal sized thyroid glands or "diffuse" thyroid diseases. During the examination the physical parameters for gain, far and near gain were constant. The normal value (means +/- 2 s) in 95 patients with normal sized and euthyroid thyroid glands was lower in females (gs: 14 +/- 4) than in males (gs: 16 +/- 6), children had obviously lower patterns (gs: 7.1), adolescents had low normal patterns (gs: 11). The echogenicity increased with increasing thyroid volumes. In patients with autoimmune thyroid diseases an obvious low echogenicity could be demonstrated (Hashimoto's thyroiditis, gs-SEM: 8.3 +/- 1.5; Grave's disease, gs-SEM: 6.7 +/- 1.2) (SEM = standard error of the mean). Euthyroid patients with microsomal antibody titers showed low normal grey scale patterns (gs: 10.9 +/- 3). In patients after subtotal thyroidectomy the grey scale pattern decreased with decreasing volume of the residual thyroid gland. The grey scale pattern increased years after surgery. The subjective grading of the grey scale pattern was different from the quantitatively measured pattern in 18% of the patients with glands of normal size.

Adolescent↗
PubMed1989

[Significance of leukocyte scintigraphy of the infected total endoprosthesis].

31 patients with suspected septic loosening of an endoprosthesis (hip endoprosthesis n = 30; knee endoprosthesis n = 1) were examined with leukocyte scans (10 MBq 111In-oxine: n = 22; 300 MBq 99mTc-HMPAO: n = 9). The results were compared with results of the bacterial growth (n = 22), the histology (n = 12) and of the bone scans (99mTc-MDP: n = 20) which were performed within 4 days. The sensitivity of the bone scan was 100%, the specificity 30% and the diagnostic accuracy regarding a septic loosening of the arthroplasty was 55%. For the leukocyte scans a comparable sensitivity of 100%, but a higher specificity (86%) and accuracy (91%) could be calculated. A false positive leukocyte scan could be observed in a periprosthetic granuloma, an ossifying periarthritis and in a patient with negative bacterial growth with the histological proof of an inflammation.

Adult↗
PubMed1989

In vivo viability of 111In-labelled granulocytes demonstrated in a sham-dialysis model.

In seven febrile patients undergoing regular dialysis treatment, sham-dialysis with a dialyzer equipped with a cuprophane membrane was performed during a routine 111In-oxine white blood cell scan with "pure" granulocytes isolated on a discontinuous gradient (Percoll/plasma: n = 5; Metrizamide/plasma: n = 2). The patients were in contact with the cuprophane membrane over 45 or 90 min. Twenty-five (+/- 5) minutes after the start of the dialysis, the peripheral leucocyte count (59 +/- 22%) and the 111In activity in the peripheral blood decreased to a minimum of their initial range (64 +/- 21%) because of leucocyte activation. The activity over both lungs increased symmetrically (29 +/- 15%), the spleen activity decreased (14.8 +/- 8%) and the liver activity remained constant. At the end of the dialysis (45-90 min post-injection), the number of circulating neutrophils, peripheral 111In activity and activity distribution in the organs regained their initial level. In conclusion, these data confirm previously described data concerning the sequestration of neutrophils into the lung during dialysis treatment. The data demonstrate the origin of the activated neutrophils in the circulation and the spleen. The identical behaviour of 111In-oxine-labelled and unlabelled granulocytes is demonstrated. Additionally, the accumulation of activity in the spleen is due not to opsonized cells but to sequestrated neutrophils, which are able to migrate from the spleen after adequate activation. The migration of activated cells into the lung explains the diagnostic difficulties posed by diffuse lung uptake in leucocyte scans in patients with leucocyte-activating diseases.

Adult↗
PubMed1989

Tc-99m-(V)-DMSA: the new sensitive and specific radiopharmaceutical for imaging metastases of medullary thyroid carcinomas?

In the follow-up of five patients with histologic proven medullary thyroid carcinoma (MTC) and raised serum calcitonin and CEA levels the pentavalent Tc-99m-(V)-DMSA and the Tc-99m-MDP bone scan had the highest sensitivity in the localisation of metastases. Both methods are not tumor specific. A false positive Tc-99m-(V)-DMSA uptake in an old osteomyelitis of one vertebra could be demonstrated. The J-123-MIBG and In-111-F(ab2)' antibody scan did not allow to localise one of the above described metastases. In conclusion in the follow-up of patients with MTC and elevated tumor marker concentrations the Tc-99m-(V)-DMSA and the Tc-99m-MDP bone scan should be the second diagnostic procedures after sonography has been performed.

Adult↗
PubMed1988

[Atypical Caroli syndrome with kidney failure in cystic renal changes].

In a 61-year-old man in terminal renal failure from bilateral renal polycystic degeneration abdominal sonography chanced to demonstrate in the left lobe of the liver a saccular, pearl string-like dilatation of the, at first no further definable, duct systems. Hepatobiliary scintigraphy revealed them to be bile-draining and thus confirmed Caroli's disease, which had previously been asymptomatic for any hepatic involvement. Since in the majority of cases of Caroli's disease renal changes are symptom-free associated findings, the question arises whether in this case there is the coexistence of polycystic renal disease and Caroli's disease or whether the biliary tract and renal changes constitute a nosological entity in the sense of atypical Caroli's disease.

Bile Duct Diseases↗
PubMed1988

[99mTc-HMPAO labeling of leukocytes and thrombocytes. Characteristics and diagnostic consequences].

The lipophilic complex 99mTc-hexamethylpropylene-amineoxime (HMPAO) is suitable for labelling of leukocytes and platelets in vitro. With a labelling efficiency of 35 to 70% of marked cells between 0.3 and 0.5 GBq of the 99mTc are re-injected into the patient. Problems in differential diagnosis arise particularly in lesions in the pelvis and abdomen because of the rapid renal elimination of the 99mTc complex, with accumulation in the kidneys and bladder. Two hours after injection, biliary excretion leads to intestinal activity. After 24 hours there was activity in the colon in all patients. In summary, labelling of cells with 99mTc-HMPAO provides a practical method based on an available radio nuclide which can be used as an alternative to 111In-oxine, but cannot altogether replace the latter method because of the specific properties and the short physical half-life of 99mTc.

Blood Platelets↗
PubMed1988

Comparison of 99Tcm-HMPAO and 111In-oxine labelled granulocytes in man: first clinical results.

The in vitro and in vivo behaviour of 99Tcm-HMPAO (hexamethylpropyleneamineoxime) (n = 12) and 111In-oxine (n = 11) labelled granulocytes, isolated by density-gradient centrifugation (Metrizamide/plasma gradients), was compared in patients with suspected inflammatory diseases. The in vitro elution of both labels and the viability of the labelled cells (99Tcm, 98.5%; 111In, 96.5%) was comparable but the labelling efficiency was different (99Tcm, 44 +/- 13%; 111In, 72.5 +/- 5.5%). In vivo, the lung (t1/2 max: 7.7 min), liver and spleen perfusion patterns were nearly identical; the image quality for detail in 99Tcm scans was superior to 111In images. The blood disappearance curves of 99Tcm and 111In were comparable. In the small number of patients examined all infections could be diagnosed correctly, without false-positive or false-negative results. Disadvantageous is the renal excretion of 99Tcm complexes (3+% over 20 h) with kidney and bladder activity from the beginning of the study. The biliary excretion in half of the patients (n = 6) with unspecific positive small and large bowel visualization and the late intestinal excretion also render the diagnosis more difficult. The recommended best imaging times for abdominal and retroperitoneal inflammations are 30 min to 2 h after injection. Late scans in septic prosthetic joints have disproportionate long acquisition times. As a potential cell labelling compound, 99Tcm-HMPAO has a promising future in comparison to 111In scans because of the good availability of 99Tcm, the image quality and the lower radiation exposure to the patient when lower activities for the early diagnosis of abdominal inflammatory diseases are reinjected.

Colitis, Ulcerative↗
PubMed1988

Radiolabelled granulocytes in inflammatory bowel disease: diagnostic possibilities and clinical indications.

Radiolabelled granulocytes in chronic inflammatory bowel diseases (CIBD) are able to diagnose the disease extent and assess the disease activity. It may be performed with 111In oxine- and 99Tcm hexamethylpropyleneamineoxime (HMPAO)-labelled cells. The granulocyte scan localizes inflamed bowel segments with an accuracy comparable with radiology and endoscopy including biopsy of the bowel (r = 0.95; P less than 0.001). The specificity of the scan for diseased segments is near 100%, the sensitivity 92%. A three-phase white blood cell scan (imaging: 0.5, 4, 20 h post injection) allows differentiation of diseased bowel segments from abscesses and fistulas. False positive results are possible in necrotic carcinomas. The 99Tcm HMPAO scan shows rapid renal and delayed biliary and intestinal excretion of tracer. In this way diagnostic problems arise in the small pelvis. Because of the intestinal and biliary excretion, early images should be obtained (0.5-2 h post injection). Later scans with 99Tcm HMPAO are of minor importance. The disease activity can very specifically be assessed by the determination of the percentage faecal 111In excretion (96 h faecal collection). Active and non-active diseases can be clearly differentiated. We found no correlation with the subjectively influenced Crohn's disease activity index (CDAI) (r = 0.25; P greater than 0.05), but good correlations with the Dutch Index (van Hees: r = 0.67), ESR (r = 0.69), serum albumin (r = -0.54) and orosomucoid (r = 0.65). The percentage faecal excretion correlates well with the histologically estimated leucocytic bowel infiltration. Because of the intestinal 99Tcm HMPAO excretion the determination of faecal excretion is pointless in 99Tcm studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Granulocytes↗
PubMed1988

99Tcm hexamethylpropyleneamineoxime (HMPAO) as a platelet label: evaluation of labelling parameters and first in vivo results.

The lipophilic 99Tcm hexamethylpropyleneamineoxime (HMPAO) complex can be used for labelling platelets as well as granulocytes. For the evaluation of optimal labelling parameters, platelets were isolated according to standard isolation procedures. The labelling efficiency (%) depends on incubation temperature (22 degrees C: 40%; 37 degrees C: 50%), incubation time (3 min: 20%; 25 min: 55%) and the incubation medium (plasma: 40%; saline: 50%). The 60 min 99Tcm elution from the platelets is around 8%. The platelet recovery, used as a quality parameter, is around 25 +/- 4% and is stable for at least 240 min. The high elution rate from the platelets leads to renal excretion of the label and so to significant kidney and bladder activity. Intestinal excretion of the label can also be frequently demonstrated. Fresh thrombotic lesions can usually be detected 4 h after reinjection of the labelled platelets, and in some patients as early as 1 h after reinjection of the platelets. In conclusion, 99Tcm HMPAO seems to be a promising platelet label for imaging thrombotic lesions but not for platelet-survival studies because of the short physical half-life of 99Tcm.

Blood Platelets↗