During spaceflight or staying in other astral body, the load on the musculoskeletal system and hydrostatic pressure difference is decreased due to decrease in gravity. Thus, the skeletal muscle, particularly that in the lower limbs, is atrophied, and bone minerals are lost via urinary excretion. In addition, the heart is atrophied, and the plasma volume is decreased, which may induce orthostatic intolerance. The vestibular-related control is also declined ? in particular, the otolith organs are more susceptible to exposure to microgravity than the semicircular canals. Advanced resistive exercise device（ARED）with administration of bisphosphonate is an effective countermeasure against bone and muscular deconditioning. However, atrophy of the heart has not been completely prevented. Further ingenuity is needed against cardiovascular and vestibular dysfunctions. For advanced human space exploration, extravehicular activity suit with higher mobility and inner pressure, which make pre-breathing unnecessary. Countermeasure for radiation should be also considered.

The measurement method for the noise property of the digital tomosynthesis image has not been standardized in any guidelines or papers. Currently, a noise in a digital tomosynthesis image has been commonly measured using a 2-D fast Fourier transform（2D-FFT）method. The purpose of this paper is to propose a new method for measuring the noise property of a digital tomosynthesis image, which applies the radial frequency（Radial）method with a limited angular range （LAR）for data acquisition. Although the Radial method was used to obtain the power spectrum from all angles（360°）around the origin, the LAR method acquired the power spectrum in the limited angle regions. When the noise properties acquired by the LAR method with the limited angles of 3°, 5° and 15° were compared to those obtained through the Radial method and the 2D-FFT method. The results of the LAR method had the large differences compared to those of the Radial method in the u-axis direction. Further, the noise property of the LAR method and the 2D-FFT method showed a higher correlation in both axis directions. In conclusion, we believe that the noise properties of the digital tomosynthesis image can be measured by using the LAR method with a limited angle of 5°.

Technologies of computer-aided diagnosis（CAD）have been applied to the detection or differential diagnosis of lesions so far. However, there are few cases where CAD technology is applied to therapy. The purpose of this study is to propose a method for the prognostic prediction of glioblastomas by using genes and image features. Our database consists of messenger RNAs（mRNAs）, MR images and survival times obtained from 62 patients（41 males, 21 females）.First,we selected 20 genes from 12042 mRNA, which were having small Deviance residuals in the univariate Cox regression. After the tumor regions in MR images were manually segmented, we calculated 94 image features such as size, shape, pixel value,and texture in the segmented tumor regions. Twenty image features were selected by the same manner used in the selection of genes. We estimated the survivor functions for 62 patients by using Cox regression with selected genes and image features. The outputs of Cox regression were evaluated by using the time-dependent receiver operating characteristic （ROC）analysis. The experimental result showed that the time-specific area under the curve AUC（t）exceeded 0.82 when the survival time less than 296 days. Because our method can provide objective information about the patient's prognosis, it would be useful for assisting in the determination of suitable treatment of brain tumor patients.

In this study, we assessed cross-sectional area of the aqueduct and the cerebrospinal fluid（CSF）flow-velocity in normal pressure hydrocephalus（NPH）using cine magnetic resonance imaging（MRI）. On a 1.5-T MRI, ECG-synchronized phase-contrast cine-MRI technique was used to measure the quantitative CSF flow-velocity in the aqueduct in patient with NPH（n=24）, atrophic ventricular dilation（VD,n=19）and healthy volunteers（control, n = 25）. The aqueductal area was measured using high-resolution T₂-weighted image in each group. The aqueductal CSF flow-velocity amplitude was significantly larger in the NPH group（19.68 ± 10.98 cm/s）than in the VD group（6.67 ± 3.88, P < 0.001）and the control group（10.98 ± 4.26, P = 0.018）. The aquedutal area was significantly lager in the NPH group（0.08 ± 0.04 cm²）than in the control group（0.03 ± 0.01, P < 0.001）, but not significantly different between the NPH and VD groups（0.08 ± 0.05, P = 1.000）. Aqueductal CSF flow-velocity in NPH increases, despite the aqueductal area increases.

The nonuniformity in X-ray intensity distributions that occur due to an anode is referred to as “trend”. When trend exists, the true performance of a detector is not obtained, and the contrast-to-noise ratio（CNR）is decreased. In order to assess detector performance, a method to measure accurate CNR from the region of interest（ROI）is required. Therefore,we did development of a trend-removal method using quality control（QC）image of computed radiography（CR）mammography to decrease the influence of trend. Trend was removed in the ROI by segmentation of ROI data, without reduction of the ROI area specified by QC guidelines for CR mammography. The guideline ROI（400 mm²）were divided into square sub-ROIs with side lengths of 1/2, 1/4, 1/8, and 1/16（1.56 mm²）of the ROI. The CNRs were obtained by further averaging the mean pixel values and variances of each sub-ROI. Finally, the CNR of guideline ROI of 400 mm²,the trend-removal CNR of sub-ROI areas of 1.56 mm², and trend-removal CNR of Legendre polynomials were compared using the Bonferroni statistical test. The difference of the two trend-removal CNRs was 0.13%, which not a statistical significant difference. Our trend-removal method was unaffected by ROI size.