Myocardial perfusion scintigraphy dosimetry: optimal use of SPECT and SPECT/CT technologies in stress-first imaging protocol.

PURPOSE: Over the past decade, nuclear medicine experts have been seeking to minimize patient exposure to radiation in myocardial perfusion scintigraphy (MPS). This review describes the latest technological innovations in MPS, particularly with regard to dose reduction. METHODS: We searched in PubMed for original clinical papers in English, published after 2008, using the following research criteria: (dose) and ((reduction) or (reducing)) and ((myocardial) or (cardiac) or (heart)) and ((nuclear medicine) or (nuclear imaging) or (radionuclide) or (scintigraphy) or (SPET) or (SPECT)). Thereafter, recent reviews on the topic were considered and other relevant clinical papers were added to the results. RESULTS: Of 202 non-duplicate articles, 17 were included. To these, another eight papers cited in recent reviews were added. By optimizing the features of software, i.e., through algorithms for iterative reconstruction with resolution recovery (IRRs), and hardware, i.e., scanners and collimators, and by preferring, unless otherwise indicated, the use of stress-first imaging protocols, it has become possible to reduce the effective dose by at least 50% in stress/rest protocols, and by up to 89% in patients undergoing a diagnostic stress-only study with new technology. With today's SPECT/CT systems, the use of a stress-first protocol can conveniently be performed, resulting in an overall dose reduction of about 35% if two-thirds of stress-first examinations were considered definitively normal. CONCLUSION: Using innovative gamma cameras, collimators and software, as well as, unless otherwise indicated, stress-first imaging protocols, it has become possible to reduce significantly the effective dose in a high percentage of patients, even when X-ray CT scanning is performed for attenuation correction.

Magnetic resonance imaging and positron emission tomography in the diagnosis of neurodegenerative dementias.

Neuroimaging, both with magnetic resonance imaging (MRI) and positron emission tomography (PET), has gained a pivotal role in the diagnosis of primary neurodegenerative diseases. These two techniques are used as biomarkers of both pathology and progression of Alzheimer's disease (AD) and to differentiate AD from other neurodegenerative diseases. MRI is able to identify structural changes including patterns of atrophy characterizing neurodegenerative diseases, and to distinguish these from other causes of cognitive impairment, e.g. infarcts, space-occupying lesions and hydrocephalus. PET is widely used to identify regional patterns of glucose utilization, since distinct patterns of distribution of cerebral glucose metabolism are related to different subtypes of neurodegenerative dementia. The use of PET in mild cognitive impairment, though controversial, is deemed helpful for predicting conversion to dementia and the dementia clinical subtype. Recently, new radiopharmaceuticals for the in vivo imaging of amyloid burden have been licensed and more tracers are being developed for the assessment of tauopathies and inflammatory processes, which may underlie the onset of the amyloid cascade. At present, the cerebral amyloid burden, imaged with PET, may help to exclude the presence of AD as well as forecast its possible onset. Finally PET imaging may be particularly useful in ongoing clinical trials for the development of dementia treatments. In the near future, the use of the above methods, in accordance with specific guidelines, along with the use of effective treatments will likely lead to more timely and successful treatment of neurodegenerative dementias.

[Satisfaction of parents or accompanying persons with vaccination services for children and youngsters being vaccinated]. / Studio sulla "soddisfazione" verso i servizi vaccinali dei genitori o degli accompagnatori dei bambini e dei ragazzi che effettuano le vaccinazioni.

A patient satisfaction survey aimed to assess the quality of immunization services was carried out as part of the new regional vaccination plan launched in Piemonte in 1999 to comply with the targets of the national immunization program. In January and February 2001, persons accompanying children for vaccination at the outpatient clinics were requested to fill a self-administered questionnaire with questions on the organization of the immunization services, the health care facilities, the attitude of the health care workers and the quality of the information provided. The response rate was 93%. Overall, satisfaction with the immunization services scored generally high, except for the quality of the information provided to the public. Many interviewees complained that the written/verbal information about the vaccination schedules was either lacking or insufficient. The survey results indicate a need for better training and updating of health care workers so that they can give immunization service users correct information as requested.

Behavioral effects of caffeine, (-)N-((R)-1-methyl-2-phenylethyl)-adenosine (PIA), and their combination in the mouse.

The effects of caffeine (1-100 mg/kg, IP), (-)N-((R)-1-methyl-2-phenylethyl)-adenosine (PIA) (0.01-1 mg/kg, IP), and of the two drugs in combination were studied in mice responding under a mult FR30 FI600 s schedule of food presentation. The lowest dose of caffeine, 1 mg/kg, had no effect on responding under either component of the mult schedule. Intermediate doses of caffeine (3 and 10 mg/kg) slightly increased responding under the FI component, while higher doses decreased responding. Caffeine only decreased responding, at doses above 30 mg/kg, under the FR component. PIA decreased responding under both components of the mult schedule in a dose-dependent, and similar, manner. In most cases, the rate-increasing effect of caffeine on FI responding was diminished when combined with a rate-decreasing dose of PIA. However, when 0.01 mg/kg PIA, a dose that had no effect alone, was combined with 3 mg/kg caffeine, the increase in rate exceeded that of caffeine alone. Rate-decreasing effects of PIA were antagonized by caffeine; with larger doses of PIA, larger doses of caffeine were required for antagonism. Thus, while the rate-increasing effects of caffeine can be either enhanced or diminished, when combined with different doses of PIA, the rate-decreasing effects of PIA are clearly antagonized by caffeine in a dose-dependent manner.