Publications by authors named "Leners N"

Objectives: Semiquantitative evaluation of tracer uptake in basal ganglia is superior to visual assessment of images in dopamine transporter (DAT) scintigraphy especially in follow-up of the patients. Manual drawing of regions of interest (ROIs) in two-dimensional (2D) transaxial slices of the single photon emission computed tomography (SPECT) datasets leads to a large inter- and intra-reader variability, while being time consuming. Our aim was to investigate a technique that extracts 3D ROIs in a fully automated fashion and thus might provide reproducible user-independent results allowing better follow-up control and large-scale clinical studies.

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Somatostatin receptor imaging with In-111 pentetreotide has been validated for the diagnosis and staging of chest tumors with neuroendocrine differentiation such as bronchial carcinoid and small cell lung cancer. In-111 pentetreotide uptake is not specific for neuroendocrine tumors because somatostatin receptors are also expressed by white blood cells, leading to the in vivo visualization sites of infection sites or active inflammation. Pleural plaques may be due to asbestos exposure or tuberculosis.

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The distribution of 99mTc-labelled human polyclonal non-specific immunoglobulin G (HIG) in the synovial fluid was studied in 14 patients with rheumatoid and non-rheumatoid arthritides. Analysis included the determination of the total activity per ml synovial fluid 6 h post-injection (p.i.

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For many hematological malignancies, high-dose chemoradiotherapy followed by bone marrow transplantation offers the best and sometimes the only chance for cure. However, the main causes of failure of this therapy are relapse and toxicity. In order to selectively deliver higher doses of radiotherapy to the bone marrow and to spare normal organs, we explored 52Fe therapy before a conventional BMT conditioning regimen.

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Unlabelled: The biodistribution of 111In-pentetreotide was assessed in patients with gastroenteropancreatic (GEP) neuroendocrine tumors or lymphoma and in control patients and analyzed as a function of scanning time, presence or absence of tumor uptake, tumor type and previous octreotide treatment.

Methods: Patients underwent imaging 4 and 24 hr after injection of approximately 200 MBq 111In-pentetreotide. The frequency of organ visualization was assessed on planar views.

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Objective: To determine the usefulness of 99mtechnetium (99mTc) immunoglobulin scintigraphy (99mTc IgG) in rheumatoid arthritis (RA) and in other arthritides.

Methods: Scintigraphic scores were compared with the Ritchie index and biochemical variables of disease activity.

Results: In RA, scintigraphic scores were reproducible and seemed to perform better than clinical scores.

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To specify the validity of bone marrow scanning using a monoclonal anti-granulocyte antibody labelled with 99mTc (BW 250/183) for the functional assessment of haemopoiesis, we compared this method with 52Fe scan in 16 patients with haematological disorders. The examinations were performed using a rectilinear whole-body scanner and the distribution of the two tracers was assessed visually and quantitatively in anatomical bone marrow segments, the spleen and liver. Qualitative comparison showed concordance in the bone marrow distribution of the two tracers in 83% of the segments.

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Unlabelled: Indium-111-pentetreotide, a radiolabeled somatostatin analog, has been proposed for imaging tumors bearing somatostatin receptors. This study evaluates the safety, efficacy and impact on patient management of this scintigraphic agent in patients with gastroenteropancreatic (GEP) neuroendocrine tumors.

Methods: We studied 47 consecutive patients with a proven or clinically suspected GEP neuroendocrine tumor who were imaged 4 and 24 hr after injection of 111In-pentetreotide.

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Unlabelled: The clinical usefulness of kit-formulated 99mTc-L,L-EC, a new renal tubular tracer agent based on a diaminodithiol ligand was evaluated in a large population of renal transplant recipients.

Methods: Fifty patients with transplants were studied. Five patients with renal insufficiency and five normal volunteers were also included to extend the range of renal function values.

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The effectiveness of bone marrow transplantation (BMT) for malignant blood diseases remains limited by the inability of the preparative regimen to eliminate the disease without causing toxicity to normal organs. We have used 52Fe to deliver radiotherapy selectively to the BM. Fourteen patients with hematologic malignancies received 52Fe before a conventional BMT conditioning regimen.

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This study compares the cell labelling characteristics of two 111In-oxinate formulations. The two preparations differ by the solubilizing agent of the chelate and the total amount of oxine. White blood cell suspensions were obtained by standard separation techniques and were labelled with either of these formulations.

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A patient with hereditary spherocytosis was admitted with mediastinal masses on the chest X-ray. 52Fe and positron emission tomography (PET) showed uptake of 52Fe in the masses and established the diagnosis of thoracic extramedullary hematopoiesis.

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Polymorphonuclear leukocytes may participate in reperfusion injury. Whether leukocytes affect viable or only irreversibly injured tissue is not known. Therefore, we assessed the accumulation of 111In-labeled leukocytes in tissue samples characterized as either ischemic but viable or necrotic by metabolic, histochemical, and ultrastructural criteria.

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The mean intrasplenic red cell transit time (STT) and the slow mixing splenic red cell volume (SSV) have been measured in patients with hereditary spherocytosis (HS), autoimmune haemolytic anaemia (AIHA) and lymphoproliferative disease (LD). There was an inverse relationship between the mean red cell life span (MRCLS) and the STT in HS (r = -0.96, P less than 0.

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Quantitative 52Fe scans were performed in 180 patients. Expansion of bone marrow was observed in 70. This bone marrow expansion was a nearly constant feature in haemolytic anaemia and in sideroblastic anaemia.

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Thirty patients with a painful hip arthroplasty had an In-111 leucocyte scan before surgical reexploration. In 12 patients, the In-111 leucocyte scan was abnormal and in all of them, microorganisms were found at the culture of the material from their hips at the operation. Among the 18 patients with a normal scan no infection was found in 17.

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The site of active intermittent gastrointestinal (GI) bleeding could not be found in a patient until abdominal scintigrams with indium-111-labeled red cells suggested that the bleeding was in the ascending colon. Right hemicolectomy abolished the hemorrhages. The binding of In-111 to the red cell is such that vascular activity could be clearly seen over a 5-day period.

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