Search results for "Radionuclide imaging"
showing 10 items of 51 documents
Total synthesis and evaluation of [18F]MHMZ.
2007
Radiochemical labeling of MDL 105725 using the secondary labeling precursor 2-[(18)F]fluoroethyltosylate ([(18)F]FETos) was carried out in yields of approximately 90% synthesizing [(18)F]MHMZ in a specific activity of approximately 50MBq/nmol with a starting activity of approximately 3GBq. Overall radiochemical yield including [(18)F]FETos synthon synthesis, [(18)F]fluoroalkylation and preparing the injectable [(18)F]MHMZ solution was 42% within a synthesis time of approximately 100 min. The novel compound showed excellent specific binding to the 5-HT(2A) receptor (K(i)=9.0 nM) in vitro and promising in vivo characteristics.
Emission tomography with a large-hole collimator (CACAO): a possible new way to improve radionuclide imaging.
2002
This work aims to improve the quality of scintigraphy. It evaluates the use of a large-hole collimator, the Computer Aided Collimation Gamma Camera Project (CACAO), in SPECT. Acquisition data from the same object were simulated for CACAO and for a conventional collimator. Better signal-to-noise ratios were found for CACAO images, whatever the number of emitted photons. This work demonstrates that high-resolution images may be obtained with large-hole collimators. The combination of CACAO and pixilated detectors may further improve radionuclide imaging.
Enhanced Functional Activity of the Cannabinoid Type-1 Receptor Mediates Adolescent Behavior.
2015
Adolescence is characterized by drastic behavioral adaptations and comprises a particularly vulnerable period for the emergence of various psychiatric disorders. Growing evidence reveals that the pathophysiology of these disorders might derive from aberrations of normal neurodevelopmental changes in the adolescent brain. Understanding the molecular underpinnings of adolescent behavior is therefore critical for understanding the origin of psychopathology, but the molecular mechanisms that trigger adolescent behavior are unknown. Here, we hypothesize that the cannabinoid type-1 receptor (CB1R) may play a critical role in mediating adolescent behavior because enhanced endocannabinoid (eCB) sig…
Intraoperative localization of malignant pheochromocytoma by 123-i-metaiodobenzylguanidine single probe measurement
1988
Metaiodobenzylguanidine (MIBG) imaging is a well-established method for locating intra- and extraadrenal pheochromocytomas. We investigated whether preoperative injection of 123-I-MIBG might be useful for intraoperative staging of chromaffine tumor cells. This was performed in a 46-year-old patient in whom the diagnosis of a malignant pheochromocytoma had been established by 123-I-MIBG imaging and enhanced catecholamine secretion. The rationale for intraoperative staging in this patient was a discrepancy between computed tomography (CI) of the abdomen and the radionuclide imaging, because scintigraphy revealed a mass with MIBG uptake in the right lower abdomen that could not be visualized b…
SPM-based count normalization provides excellent discrimination of mild Alzheimer's disease and amnestic mild cognitive impairment from healthy aging☆
2008
Statistical comparisons of [(18)F]FDG PET scans between healthy subjects and patients with Alzheimer's disease (AD) or amnestic mild cognitive impairment (aMCI) using Statistical Parametric Mapping (SPM) usually require normalization of regional tracer uptake via ROIs defined using additional software. Here, we validate a simple SPM-based method for count normalization. FDG PET scans of 21 mild, 15 very mild AD, 11 aMCI patients and 15 age-matched controls were analyzed. First, we obtained relative increases in the whole patient sample compared to controls (i.e. areas relatively preserved in patients) with proportional scaling to the cerebral global mean (CGM). Next, average absolute counts…
Alpha emitting nuclides in nuclear medicine theranostics.
2021
Theranostic applications with radio-isotopes currently are rapidly progressing and expand nuclear medicine application in clinical routine. Alpha emitting isotopes, in particular, have long been hypothesized to achieve relevant advances for the treatment of malignancies. Here, an overview of their properties and the knowledge of radiobiology is reviewed in view of clinical translation. Clinical evidence of radiopharmaceuticals based on alpha emitters is summarized with a focus on recent developments for treatment of metastasized castration resistant prostate cancer.Theranostische Anwendungen mit Radioisotopen machen derzeit rasche Fortschritte und erweitern den Einsatz der Nuklearmedizin in…
[Cystic dysplasia of rete testis associated with ipsilateral renal agenesis. Case report].
2003
Cystic dysplasia of the rete testis is a rare abnormality often associated with the ipsilateral agenesis of kidney. This malformation is due to a development defect of the mesonephric duct which is the cause of both the dilation of the testicular rete testis and renal agenesis. A case of this rare malformation, showing all the peculiarities described in the medical literature, is presented. A 3 years-4 months boy was examined for an asymptomatic left scrotal mass; thus, he underwent ultrasonography, which showed a multiple tubular and cystic dilatation of left rete testis, associated with the absence of left kidney, afterward confirmed by MAG3-radionuclide scan. Diagnosis was also validated…
The role of combined techniques of scintigraphy and SPECT/CT in the diagnosis of primary hyperparathyroidism
2019
Abstract Rationale: Primary hyperparathyroidism, usually as a result of a hyperfunctioning parathyroid gland, represents more than 90% cases of patients evaluated for hypercalcemia. Combined techniques of preoperative scintigraphy and SPECT/CT serve as a successful minimally-invasive parathyroidectomy. This recent imaging method provides four-dimensional functional images with advanced contrast resolution which greatly facilitates preoperative localization of parathyroid adenomas. Patient concerns: We presented the case of a male Caucasian patient, aged 67 years, who was investigated for hypercalcemia. Increased levels of parathormone, cervical ultrasonography without pathological changes, …
False-positive I-131 whole-body imaging after I-131 therapy for a follicular carcinoma.
1997
A 57-year-old man was treated with ablative radioiodine therapy for follicular thyroid carcinoma. The post-therapeutic whole body scans detected radionuclide accumulation in the area of the right occiput at the site of a cranial defect. The defect was caused by trauma in 1964. Bone scintigraphy did not show increased uptake in this area. Magnetic resonance imaging showed porencephaly, but it did not show a metasasis.
Noradrenergic innervation of the pineal gland — histochemical basis of scintigraphic imaging?
1987
There is first evidence that the adult human pineal gland may be equipped with noradrenergic fibers as is the case in a variety of mammalian species. It therefore appears worthwhile to investigate the capacity of pineal noradrenergic nerves to take up 123I-MIBG, a prerequisite for scintigraphic imaging.