OBJECTIVE Chemical reactions involved in preparing 99mTc radiopharmaceuticals occasionally result in products of substandard purity. A retrospective examination of preparation problems that occurred in the author's institution was conducted to better define the incidence, recognize patterns and identify causes of substandard 99mTc radiopharmaceutical products. METHODS All 99mTc radiopharmaceu...

BACKGROUND Thallous chloride (201Tl) and hexakis(2-methoxyisobutyl isonitrile) technetium (I) (99mTc-SESTAMIBI) are myocardial perfusion imaging agents with biological properties that also reflect tissue viability. Initial myocellular uptake rates of 201Tl reflect activity of Na,K-ATPase, whereas those of 99mTc-SESTAMIBI reflect mean plasma membrane potential. METHODS AND RESULTS To better un...

Human immunodeficiency virus (HIV) infection can cause variable movement disorders, including parkinsonism. HIV-related parkinsonism usually responds well to highly-active antiretroviral therapy (HAART), suggesting a possible reversible dysfunction of the dopaminergic system. We report the case of a 42-year-old man who presented with rapidly progressive symmetric parkinsonism, cognitive decline...

UNLABELLED We report here the results of studies on the in vitro receptor binding affinity, in vivo tumor uptake and biodistribution of two 99m-Tc-labeled peptides. METHODS Peptides P587 and P829 were synthesized by N-alpha-Fmoc peptide chemistry, purified by reversed-phase HPLC and characterized by fast-atom bombardment mass spectrometry. The peptides were labeled with 99mTc by ligand exchan...

BackgroundEarly diagnosis of transthyretin cardiac amyloidosis (ATTR-CA) is important. The aim this study was to validate the ‘Kumamoto criteria’ for prediction technetium-99m pyrophosphate (99mTc-PYP) scintigraphy positivity.MethodsOne hundred fifty patients (median age: 79.4 years, 117 males) with possibility ATTR-CA who underwent 99mTc-PYP were assessed. We divided into 4 groups (groups scor...

Monoclonal antibodies (MAbs) against high-molecular-weight melanoma-associated antigen (HMW-MAA) have been used in vivo to target melanoma. More recently, single chain Fv (scFv) antibody fragments against HMW-MAA have been described that may improve melanoma targeting. However, there have been few in vivo studies with antimelanoma scFvs because these have proved difficult to label with isotopes...

Technetium-99m (99mTc) has been used in nuclear medicine and in biomedical research to label molecular and cellular structures employed as radiotracers. Here, we have evaluated, on a DNA repair proficient Escherichia coli strain, the 99mTc decay inactivation and the influence of the (i) pre-treatment with metal ion chelators or of the (ii) treatment with a free radical scavenger on the protecti...

OBJECTIVE Primary hyperparathyroidism (pHPT) is characterised by increased parathyroid hormone (PTH) secretion and consequently increased plasma calcium. During the last few decades parathyroid scintigraphy (PS), is applied in almost all patients with pPHT before surgery and specifically before minimally invasive parathyroidectomy. The aim of this study was to find the best cut-off levels of to...

The feasibility of localizing human atherosclerotic plaques by gamma scintillation camera external imaging with technetium-99m-labeled low density lipoproteins (99mTc-LDL) was tested in 17 patients who had atherosclerosis. Imaging demonstrated focal accumulation of radiolabel consistent with 99mTc-LDL sequestration by plaques in the carotid, iliac, or femoral vessels of four patients 8 to 21 ho...

BACKGROUND 99mTc-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) has recently been explored for the characterization of indeterminate renal masses. As judged by increased intra-tumoral radiotracer uptake, we have previously reported the excellent diagnostic performance characteristics of this test for identifying benign/indolent oncocytomas and hybrid oncocyt...