Japanese Journal of Radiological Technology

The purpose of this study was to clarify the effects of the increased field strength of 1.5T vs. 3.0T on blood vessel contrast and saturation in 3D time of flight MR angiography. Vessel contrast and saturation effect were evaluated for various flow velocities and flip angles using a steady-state flow phantom. The results showed increased vessel contrast and decreased saturation of blood on 3.0T compared to 1.5T, due to the following factors: 1) sufficient saturation of stationary tissue by extended T1 relaxation time, 2) increased signal-to-noise ratio (SNR), and 3) high in-flow effect. However, the blood signal on 3.0T revealed a strong tendency to phase dispersion compared to that of 1.5T. Therefore, in order to exploit the characteristic of high field strength in 3.0T, it is suggested that adequate consideration of these factors is important in setting the image acquisition parameters.

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Multiple data evaluation is desirable for data obtained by positron emission tomography (PET), as the data follow the Poisson distribution. Such evaluation, however, tends to be very complicated, since the countrates change with nuclide decay. To solve this problem, we propose a new data scan protocol in this communication. With this method, the true+scatter coincidence counts were computed during the initial one-minute scanning, which was fixed as the standard. A dynamic scan was then performed with the fixed counts from the high count-rate region. Regions with ±2.5% of the image noise of the standard image was chosen to provide the data for evaluation. These were found to be the regions of 16.5-25.5kcps (2D) and 81.1-138.5kcps. Image quality was found to be affected by noise (2D) and random coincidence. Using this method, multiple data could be obtained by a single experiment, and very reliable image evaluation could be done.

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Voxel-based Specific Regional Analysis System for Alzheimer's Disease (VSRAD) has developed recently as an adjunctive diagnostic tool for early Alzheimer-type dementia (ATD), using three-dimensional (3D) MRI with statistical parametric mapping (SPM), and for the objective evaluation of brain atrophy. However, it takes more than five minutes to acquire MRI data by the 3D gradient echo method (3D FFE), resulting in low-throughput performance and motion artifact. These problems interrupt the application of daily MRI study. In this study, we recruited 20 patients suspected of having ATD who then underwent continuous 3D FFE MRI studies with and without the SENSE method. It was found that the VSRAD results of MRI data with SENSE were nearly to equal to those without SENSE, in spite of the prediction of a decline in source-to-noise ratio due to the reduction factor in the SENSE method.

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This study attempted to clarify whether medical radiological technologists of the Japanese Society of Radiological Technology in Gunma sought to obtain Bachelor degrees and Master of Science degrees. In September 2005, a postal questionnaire survey was conducted on a sample of 153 technologists, and 68.0% (104/153) of the questionnaires were returned. The percentage of respondents who wished to obtain a degree was 25.0% (26/104). The first reason for wishing to obtain a degree was to improve the quality of their work 47.8% (11/23). Moreover, 28.8% (30/104) of respondents indicated a desire to obtain a master's degree. A total of 103 respondents indicated the subject they wished to study: 45.6% (47/103) indicated their own specific area, and 34.0% (35/103) indicated clinical psychology. The results of the survey showed that a high ratio of radiological technologists in Gunma would like to obtain an advanced degree. Even the radiological technologists who did not wish to obtain an advanced degree indicated their desire to continue in more specialized areas of radiology. The above investigation suggested some ways to implement lifelong education at the Gunma Prefectural College of Health Sciences.

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