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Taizo Sanada

Publications and source records attributed to Taizo Sanada.

4 recordsLinked to original sources

[Selection of parameters for multi-objective frequency processing in CR mammography: visual evaluation of mammographic phantom images].

The multi-objective frequency processing installed in the FCR5000R (Fuji Film Medical) is superior to the conventional processing used in the FCR9000 (Fuji Film Medical) in evaluating frequency processing. A suitable combination of parameters for multi-frequency-processing in computed radiography (CR) mammography was evaluated. The paired-comparison method using phantom images was performed for the visual evaluation. Results showed that the evaluation score of mass and fiber lesions depended on the multi-frequency balance type (MRB) parameter, and the low-frequency-cycle emphasizing parameter had the highest score. In contrast, the score of microcalcifications depended on the degree of multi-frequency enhancement (MRE). The most suitable parameters for the multi-frequency processing of every size and type of breast lesion were not obtained. However, MRB=A, MRT=p, and MRE=1.0 can be recommend for CR mammography.

Humans↗

[Measurement of effective dose of the assisting person in diagnostic X-ray examination].

We measured the effective dose received by the person assisting the patient at diagnostic X-ray examination. Measurement was done when a patient's chest, abdomen, lumbar vertebrae, hip joint, skull, cervical vertebrae, or knee joint was examined by radiography. A body phantom including human bones exposed to radiation was used in the role of the patient. Some exposure conditions for these measurements were the same as those used routinely in computed radiography. Effective dose was measured directly with an ionization survey meter. As a result, the effective dose of the person assisting with axial projection of the hip joint was 124 microSv, which was higher than that for other regions and projections. If the assisting person helped a patient without using any protective device, the effective dose would be low enough to ignore. However, because medical staff are frequently exposed to radiation, optimal protection is crucial to prevent unnecessary radiation.

Hip Joint↗

[Significance of the visual evaluation method using the two-visit method (two-sample preference test suggested by Ferris)].

To increase the accuracy of the visual evaluation method, we studied the significance of the two-sample preference test using the two-visit method, as proposed by Ferris. Advantages of this method include not only its ability to estimate whether the image quality of the sample is statistically the same but also its ability to distinguish the difference between samples more clearly than when using the conventional two-sample preference test or paired-comparison method. However, a disadvantage is that this method involves two observations of the same sample. When using chest images, even if a difference between the samples is not recognizable by the conventional method, a significant difference can be elicited with this method. The data obtained by this method can be evaluated with the paired-comparison method, so some samples may be ranked as well. Therefore, we verified that the two-sample preference test, which Ferris formulated, is useful in visual evaluations.

Humans↗