Exosomes known as nano-sized extracellular vesicles attracted recent interests due to their potential usefulness in drug delivery. Amid remarkable advances in biomedical applications of exosomes, it is crucial to understand in vivo distribution and behavior of exosomes. Here, we developed a simple method for radiolabeling of macrophage-derived exosome-mimetic nanovesicles (ENVs) with (99m)Tc-HM...

The goal of this teaching case study is to demonstrate the novel use of (99m)Tc-HMPAO-labeled white blood cells (WBCs) in diagnosing chronic recurrent multifocal osteomyelitis (CRMO). (99m)Tc-HMPAO-labeled white blood cells were utilized to diagnose CRMO. Classically, CRMO is evaluated scintigraphically using (99m)Tc-methylene diphosphonate/hydroxymethylene diphosphonate. (99m)Tc-HMPAO-labeled ...

in recent years, several radiopharmaceuticals have been developed for imaging regional cerebral blood flow (rcbf) such as 75se labelled pipse and mose, ²º¹ti labelled ddc and 99mtc labelled hmpao. hmpao with two asymmetric carbon atoms (at the 3 and 9 positions), produces d,1 and meso isomers, only one of which is retained in the brain. rapid intracellular conversion of 99mtc-d,1-hmpao to hydro...

We present an autopsy case of primary leptomeningeal melanoma visualized with technetium-99m-hexamethylpropyleneamine oxime (Tc-99m-HMPAO) single photon emission CT (SPECT) of the brain. Increased uptake of Tc-99m-HMPAO coincided with leptomeningeal enhancement on MR images and with the tumor location of the autopsy findings. It was thought that Tc-99m-HMPAO could correlate closely with melanom...

UNLABELLED Rheumatoid arthritis (RA) involves the accumulation of monocyte-derived macrophages in the affected synovial tissue. This process of cell migration could be portrayed scintigraphically to monitor noninvasively the effects of therapy on the progress of the disease. For this purpose, labeling of purified autologous monocytes with 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) at ve...

BACKGROUND Hashimoto's encephalopathy (HE) is a rare immune-mediated encephalopathy associated with autoimmune Hashimoto's thyroiditis. OBJECTIVES AND METHODS We report on a patient with HE and significant clinical improvement correlating with an increase in cerebral blood flow demonstrated by hexamethylpropyleneamine oxime (HMPAO) single-photon emission computed tomography (SPECT). HMPAO-SPE...

UNLABELLED SPECT using 99mTc-hexamethyl propyleneamine oxime (HMPAO) mainly reflects regional cerebral blood flow, however metabolic abnormalities also affect the retention of 99mTc-HMPAO. METHODS To rule out any flow factor, a test-tube model was used to evaluate the effects of metabolic alterations both on intracellular trapping of 99mTc-HMPAO and on extracellular glutamate and lactate dehy...

The sensitivity of technetium-99m- (99mTc) d,l-HMPAO to radiolytically induced dissociation in aqueous solutions was investigated. It was found that cobalt-60 (60Co) gamma irradiation of solutions containing 99mTc-d,l-HMPAO with only 1600 cGy reduced the lipophilic chelates' radiochemical purity (RCP) to 50%-60%. The radiolytic sensitivity of 99mTc-meso-HMPAO is significantly lower. The results...

In recent years, several radiopharmaceuticals have been developed for imaging regional cerebral blood flow (rCBF) such as 75Se labelled PIPSE and MOSE, ²º¹TI labelled DDC and 99mTc labelled HMPAO. HMPAO with two asymmetric carbon atoms (At the 3 and 9 positions), produces d,1 and meso isomers, only one of which is retained in the brain. Rapid intracellular conversion of 99mTc-d,1-HMPAO to...

The ideal imaging method in inflammatory bowel disease would reliably detect inflammation, identify the correct intestinal location, and assess the severity of the disease. The aim of this study was to compare scintigraphic methods of quantifying overall disease activity using both indium-111 (111In) and technetium-99M (99mTc) HMPAO labelled leucocyte scans. The four day faecal excretion of 111...