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Biomedical subjects

A Hotze

Publications and source records attributed to A Hotze.

At least 37 records · Page 2Linked to original sources

[Increased sensitivity of whole-body scintigraphy with I131 for the detection of iodine-accumulating metastases by means of delayed imaging].

In the follow-up of thyroid cancer patients we sometimes observed discrepancies between elevated thyroglobulin levels and negative results of posttherapeutic or diagnostic scans 48 h and 72 h after oral application of 131I routinely. Consequently, delayed 131I scans (96 h and later) were performed in addition. In all cases, delayed 131I scans either showed a higher imaging quality or additional metastatic lesions. Thus, posttherapeutic (and diagnostic) scans should include late images (4 d and later).

Administration, Oral↗

[Bone marrow scintigraphy and magnetic resonance tomography in plasmacytoma].

In 17 patients suffering from plasmocytoma bone marrow scintigraphy (BMS), and magnetic resonance tomography (MRT) was performed. RES expansion in the extremities was found by both methods, MRT also visualized a diffuse infiltration of the marrow. In that location, cold lesions in BMS correspond to yellow marrow. In the pelvis, however, cold lesions are due to tumor involvement. Both methods offer additional diagnostic opportunities and may in the future allow to expand the time intervals between routinely performed iliac crest biopsies.

Aged↗

[Inhalation scintigraphy of the lung using the new ultrafine aerosol Technegas].

Evaporation of 99mTc-pertechnetate at about 2500 degrees C on a carbon surface generates an ultrafine aerosol of labelled carbon clusters. Its particle size of about 2-5 nm enables the aerosol to behave similarly to a gas regarding the ability of penetration. After inhalation, the radioactive particles adhere to the walls of the respiratory bronchioli and alveoli. The high concentration of the radioactivity in the argon carrier gas makes it possible to record a scintigram after a single deep breath. We studied four healthy volunteers and 79 patients including 34 with a tentative diagnosis of pulmonary embolism, 20 with bronchus carcinoma, and 15 with various other lung diseases. Ten of these patients were infants, the youngest being nine months old. All patients also had a perfusion scintigraphy.

Administration, Inhalation↗

[The significance of testicular scintigraphy for the differential diagnosis of the acute scrotum].

Scrotal scans were performed in 100 juvenile or grown-up patients suffering from acute scrotal pain. Employing the standard equipment of a nuclear medicine department this examination which takes only a few minutes, had a very high accuracy (93%). Especially each torsion was diagnosed correctly. Quantitative analysis of the scans did not yield additional information compared to visual evaluation, and was therefore abandoned. In three patients presenting with traumatic scrotal hematoma the testicular perfusion was judged correctly posttraumatically and in follow-up scans.

Acute Disease↗

[The modification of 201Tl-SPECT of the myocardium by breast absorption].

The attenuation effect of the female breast on single-photon emission computed 201Tl-chloride myocardial tomograms (SPECT) was quantitatively evaluated in a group of 20 women. SPECT was carried out with the left breast in the normal position and after its maximal upward displacement. The count rate gain was up to 30% when the breast was raised. 201Tl-chloride myocardial SPECT often showed false lesions in the anterior wall which resulted from the attenuation of the gamma rays by the female breast. This factor is neglected in constructing the tomograms, and even if such artifacts are absent, the attenuation may adversely affect the calculated wash-out values.

Absorption↗

[Nuclear medicine diagnosis of heart involvement in progressive systemic scleroderma].

The frequency and extent of heart involvement in progressive systemic scleroderma (PSS) can be underestimated when current clinical diagnostic methods are used. We therefore studied 53 PSS patients with planar (201Tl) chloride myocardial scintigraphy, and 44 PSS patients with radionuclide ventriculography using red blood cells labeled in vitro with 99mTc. Comparison of maximal exercise and resting myocardial scans demonstrated pathologic findings in 18 of 38 patients. In 10% of the patients abnormal ejection fraction values (less than 50%) and Fourier analysis were found on radionuclide ventriculography. Myocardial scintigraphy in conjunction with other diagnostic modalities thus provides useful information for the evaluation of heart involvement in PSS.

Cardiac Output↗

[Nuclear medicine diagnosis and therapy of distant metastases of pheochromocytoma].

Three foci, suspected of being metastases, were discovered by sonography and computed tomography in a patient twelve years after resection of a phaeochromocytoma and six years after resection of liver metastases. The findings were confirmed by scintigraphy with 131I-metaiodobenzylguanidine (MIBG) and treated with 3700 MBq of MIBG, to be repeated in the near future.

3-Iodobenzylguanidine↗

[Nuclear medicine diagnosis of Alzheimer type dementia].

Eleven patients with Alzheimer type dementia were investigated by single-photon-emission computed tomography (SPECT) using 99mTc-hexamethylpropylene-aminoxim (HM-PAO). Nine had a typical, symmetrically reduced enrichment in the parieto-temporo-occipital area. In three of these nine patients a similar pattern was recorded additionally in the frontal, in the remaining two in the temporal or parietal region. In a semi-quantitative evaluation radioactivity concentrations in the cerebrum and cerebellum were compared. It demonstrated that there was in relation to the cerebellum a reduced concentration in seven of the eight studied cerebral regions. The relative blood flow of the parieto-temporo-occipital region was most markedly affected and in patients with Alzheimer type dementia was reduced by 25% below that of normal subjects. The results indicate that cerebral SPECT with HM-PAO is a reasonable method of investigation to confirm the diagnosis of "Alzheimer type dementia" and exclude other cerebral disease, especially if pathognomonic findings are to be obtained.

Alzheimer Disease↗

Localization and activity of inflammatory bowel disease using 111In leukocyte imaging.

A prospective study was initiated to compare the clinically proven results concerning localization/extent and activity of inflammatory bowel diseases with those of 111In-oxine leukocyte imaging. All patients studied were completely examined with barium enema x-ray, clinical and laboratory investigations, and endoscopy with histopathology. A total of 31 leukocyte scans were performed in 15 patients (12 with Crohn's disease, 3 with ulcerative colitis). The scans were graded by comparing the cell uptake of a lesion (when present) and a bone marrow area providing a count ratio (CR). The inflammatory lesions were correctly localized on 26 leukocyte scans, and in 21 scans the scintigraphically estimated extent of disease was identical to endoscopy. In 5 cases the disease extent was underestimated, 4 scans in patients with relapse of Crohn's disease were falsely negative, and in one patient with remission truly negative. The scintigraphically assessed disease activity was also in a good agreement with clinical disease activity based on histopathology in all cases. We conclude that leukocyte imaging provides valuable information about localization and activity of inflammatory bowel disease.

Adult↗

[Experience with a high-dose therapy concept in metastatic differentiated thyroid cancer].

Three patients with pulmonary metastases from differentiated thyroid carcinoma were treated with radioiodine. As a first treatment either 1.85 GBq (50 mCi) or 3.7 GBq (100 mCi) were given followed by doses of 11.1 GBq (300 mCi) 131I. In one patient the pulmonary metastases disappeared completely, the two other patients showed a significant regression. In one patient possibly radiation-induced pancytopenic changes appeared after the third and fourth radioiodine treatment, in the other two patients side-effects were not seen.

Adenocarcinoma↗

[HMPAO-SPECT in cerebral seizures].

In nine patients with suspected psychogenic seizures and in three patients with proven epileptic seizures HMPAO-SPECT was performed prior to and during seizure. In the patients with later on-proven psychogenic seizures no, or only slight, changes of regional cerebral blood flow were found. Patients with proven epilepsy revealed partly normal findings interictally but during seizure a markedly increased circumscript blood flow was found in all patients. Even though PET is superior to SPECT with respect to spatial resolution, in the diagnosis of seizures HMPAO-SPECT has the advantage of enabling injection of the tracer during the seizure and the performance of the SPECT study subsequently.

Epilepsy↗

[Comparison of 99m Tc-HMPAO-labeled leukocytes and 99m Tc-nanocolloid in osteomyelitis].

Six patients with proven or suspected osteomyelitis were studied with both 99mTc-HMPAO-labelled leukocytes and 99mTc-nanocolloid. In all cases the findings of both procedures were in good agreement. In 3 patients there was markedly increased accumulation of labelled cells and colloid, respectively. Two patients showed slightly increased accumulation of both agents and in one patient the finding was (correctly) negative. Further studies are necessary to determine whether or not colloid scintigraphy might replace the time-consuming leukocyte scintigraphy.

Adult↗

[MR tomography in lymphatic and leukemic bone marrow infiltrations. A comparison with scintigraphy and conventional x-ray diagnosis].

MR is the only noninvasive procedure that can demonstrate changes in the medullary space. If it is combined with bone marrow scintigraphy and conventional x-ray film diagnostics, it can yield a comprehensive diagnosis of bone marrow infiltrations in the regions of the pelvis, thighs and lumbar vertebral column in leukaemia or malignant lymphomas. The T1 relaxation times of the malignant infiltrations are enhanced compared with normal fatty marrow. MR tomography of the bone marrow is particularly suitable for determining the therapy or follow-up control of a malignant systemic disease.

Bone Marrow↗

[Reversible functional disorders of the intestinal tract caused by abdominal radiotherapy].

In 20 patients with malignancies receiving abdominal radiotherapy, tests for disturbed intestinal functions were performed at the beginning and at the end of the therapy and after 6 to 12 month following radiation. Four noninvasive tests were performed: 75Se-homotaurocholate (75SeHCAT) test for estimation of bile acid malabsorption; Schillings test for quantification of vitamin B12 absorption; H2-breath analysis before and after a test meal containing lactose as a parameter of lactose malabsorption; and 51Cr-EDTA test for estimation of intestinal permeability. Both bile acid and vitamin B12 absorption decreased significantly towards the end of abdominal radiotherapy in more than 50% of patients. Only one patient developed lactose malabsorption. After 6 to 12 month, these abnormalities had completely disappeared. In contrast, small intestinal permeability did not increase during radiotherapy but was significantly elevated 6 to 12 month following treatment as the only indication of chronic injury of small intestinal mucosa. During radiotherapy, a significant correlation existed between the severity of diarrhea and the degree of bile acid malabsorption.

Diarrhea↗

The nonspecific clearance function of the reticuloendothelial system in patients with immune complex mediated diseases before and after therapeutic plasmapheresis.

The nonspecific clearance function of the reticuloendothelial system (RES) in six patients with immune complex mediated systemic vasculitis was determined by the evaluation of the disappearance rate of technetium 99m labelled microaggregated human serum albumin colloid (MHAC) injected IV before and after therapeutic plasma exchange. Three patients with systemic lupus erythematosus (SLE) and one patient with immune complex vasculitis (ICV) exhibited a significant clinical improvement after plasmapheresis which was paralleled by an accelerated MHAC elimination rate following plasma exchange therapy. One patient with ICV and unresponsive to plasma exchange showed delayed MHAC elimination. In one patient with myasthenia gravis (MG), the elimination rate was not altered by plasmapheresis. The data obtained indicate that nonspecific clearance of the RES may be one effect of plasma exchange therapy in patients with immune complex mediated diseases.

Adolescent↗