Evaluation of Driver's Brain Activity Associated with Advanced Driving Skills Such as Cornering.

Evaluating the driving ability of a vehicle is important in the development of in-vehicle systems and the training of driving skills. Driving ability has been investigated extensively in terms of recognition, judgment, and operation. However, the role of the brain in advanced driving operations within the limits of vehicle performance has not been thoroughly investigated. In this study, we perform functional magnetic resonance imaging to evaluate brain functions associated with advanced driving skills when drivers are shown a video of cornering involving a vehicle slipping sideways. Based on the results, the skilled driver group indicates broad activity in both the right and left parietal associations, right-side primary somatosensory, left-side premotor, and supplementary motor areas. Because the premotor cortex is a region involved in the execution of movement, whereas the supplementary motor cortex is a region involved in spontaneous movement, it is assumed that the skilled drivers visualized the driving operation, and that the brain functions necessary for the operation are activated. These findings indicate that drivers with high skill levels exhibit distinctive brain activities. We believe that a further understanding regarding the brains of skilled drivers will facilitate the development of in-vehicle control that incorporates high driving skills and training.

Utility of Echo-planar Imaging with Compressed Sensitivity Encoding (EPICS) in the Evaluation of Small Breast Cancers Using Diffusion-weighted Imaging with Background Suppression (DWIBS).

PURPOSE: High b-value acquisition and diffusion-weighted imaging with background suppression (DWIBS) are desirable in high-specificity breast cancer diagnosis on non-contrast-enhanced magnetic resonance imaging; however, this inherently results in a lower signal-to-noise ratio (SNR). Compressed sensitivity encoding (C-SENSE), which combines SENSE with compressed sensing, improves the SNR by reducing noise. Recent technological improvements allow us to incorporate this acceleration technique into echo-planar imaging, called echo-planar imaging with C-SENSE (EPICS). This study aimed to compare image quality and reliability of the apparent diffusion coefficient (ADC) between DWIBS obtained using SENSE and EPICS in patients with small breast cancers. METHODS: Thirty-seven patients with pathologically confirmed breast cancer underwent DWIBS, and images were reconstructed using both conventional SENSE (SENSE-DWIBS) and EPICS (EPICS-DWIBS). Two board-certified radiologists independently evaluated lesion conspicuity (LC) and noise using a 5-point grading scale. The same 2 radiologists independently measured SNR, contrast-to-noise ratio (CNR), and the mean cancer ADC. The Pearson coefficient and Bland-Altman plot were applied to assess the accuracy of ADCs. RESULTS: LC scores were higher with EPICS than with SENSE, reaching significance for one reviewer but not the other reviewer. Noise ratings on visual evaluation were significantly lower with EPICS than with SENSE (P < 0.001 for both reviewers). SNR was significantly higher with EPICS than with SENSE (P < 0.005 for both reviewers). CNR was significantly higher with EPICS than with SENSE (P < 0.001 for both reviewers). Bland-Altman plots of cancer ADCs using EPICS-DWIBS and SENSE-DWIBS showed excellent concordance, with a bias of 0.026 × 10-3 mm2/s and limits of agreement ranging 0.054 × 10-3 mm2/s; the Pearson's correlation coefficient was 0.997 (P < 0.0001). CONCLUSION: EPICS enhances breast DWIBS image quality, with improved SNR and CNR and reduced noise levels. The ADCs of breast cancers obtained using EPICS were almost perfectly correlated with those obtained using conventional SENSE.

Simultaneous Visualization of the Thoracic Duct and Blood Vessels Using MRI: A Comparison Between Balanced Turbo-field-echo and Spin-echo.

OBJECTIVE: Magnetic resonance thoracic ductography (MRTD), concomitant with blood vessel imaging, provides useful anatomical information. The purpose of this study was to assess the visibility of the thoracic duct and blood vessels simultaneously by MRTD using balanced turbo-field-echo (bTFE) and turbo spin-echo (TSE). METHODS: MRTDs concomitant with blood vessel imaging on bTFE and TSE were obtained for 10 healthy volunteers with a 1.5T-magnetic resonance unit. Visibility of the thoracic duct, blood vessels in the thoracic region; motion artifacts; and overall image quality were scored by two radiologists using three-to-five-point scales; those were compared between bTFE and TSE. RESULTS: The thoracic duct was generally well-visualized on MRTD sequences. The upper part of the thoracic duct was better visualized on TSE than on bTFE (p < 0.05). The blood vessels were well visualized on bTFE and TSE; the bilateral subclavian arteries and the right subclavian veins were better visualized on TSE than on bTFE (all p < 0.05). Motion artifacts and overall image quality were better on TSE than on bTFE (p = 0.0039 and 0.0020, respectively). CONCLUSION: MRTD concomitant with blood vessel imaging on TSE has better visibility of the thoracic duct and blood vessels than bTFE.

Gymkhana and pylon slalom driving training effects on the cerebellum structure.

To develop a suitable automobile design as per each driver's characteristics and state, it is important to understand the brain function in acquiring driving skills. Reportedly, the brain structures of professionals, such as athletes and musicians, and those who have received training in special skills, undergo changes with training. However, the development process of the brain in terms of acquiring driving skills has not yet been clarified. In this study, we evaluated the effects of driving training on the brain and observed an increase in the volume of the right cerebellum after short-term training (3 days). The right cerebellum is responsible for controlling the right hand and right foot, which are important for driving. Drivers train to control a vehicle smoothly at high speeds at gymkhana and pylon slalom courses, which are often used in motor sports. The brain structure was analyzed before and after training using magnetic resonance imaging. Voxel-based morphometry was used to assess possible structural changes. First, the lap times after training were clearly shortened and vehicle dynamics were more stable, indicating that the drivers' skill level clearly improved. Second, brain structural analysis revealed a volumetric increase in the right cerebellum. The cerebellum is involved in the process of learning sensory motor skills, such as smooth steering and pedal operations, driving course shape, and vehicle size perception. These results suggest a new inner model for driving operation and support the hypothesis that motor learning affects the cerebellum during vehicle driving training.

[Effect of Contrast on FLAIR by Changing the Number of Packages].

We have found that the number of packages influences contrast for brain tissue signals on fluid-attenuated inversion recovery (FLAIR). The purpose of this study was to evaluate the contrast of white and gray matters by changing the number of packages. In a volunteer study (n=8), FLAIR images were obtained with the various number of packages (number of package=2, 3, 4, 5). We investigated the same imaging condition at both 1.5 and 3.0T. The signal intensity of white and gray matters in all volunteers was increased as increasing the number of packages. Moreover, the contrast ratio between white and gray matters was slightly decreased. In our conclusion, the contrast between the gray and white matters on FLAIR was influenced by the number of packages.

Development of the C(6+) laser ablation ion source for the KEK digital accelerator.

A laser ion source that provides a fully ionized carbon ion beam is under joint development at the High Energy Accelerator Research Organization and Brookhaven National Laboratory. Long-pulse (6 ns) and short-pulse (500 ps) laser systems were tested by using them to irradiate a graphite target. Notable differences between the systems were observed in these experiments. Preliminary experimental results, such as the charge-state spectrum, beam intensity, and stability, are discussed.

[Problem of spectral attenuated with inversion recovery fat suppression method with respiratory-gated].

The purpose of this study was to investigate the effect of fat suppression when we use respiratory-gated spectral attenuated with inversion recovery (SPAIR) method with respiratory-gated. We experimented on phantom and in-vivo study using simulated wave of respiratory-gated SPAIR at 1.5 tesla and 3.0 tesla. As a result, the effect of fat suppression becomes wrong with longer intervals of inspiration and expiration by wave of respiratory-gated. The signal intensity also varies with each slice. This result had the same trend on phantom and in-vivo study. The longitudinal magnetization of fat becomes a stable state when SPAIR pulse is shot more than once. However, the SPAIR method with respiratory-gated collect signal before the longitudinal magnetization of fat to be stable state, and fat suppression effect becomes bad, because the inversion time does not match the null point of the fat. Therefore, when we use SPAIR method with respiratory-gated it always causes bad fat suppression.

A calculation model for serum ionized calcium based on an equilibrium equation for complexation.

Measurement of ionized calcium is more important than measurement of total calcium in serum samples. In the present study, equations were derived from complexation and acid dissociation equilibrium equations, and were used to determine the concentration of ionized calcium from the observed serum concentrations of total calcium, albumin, total protein, and inorganic phosphate. The ionized calcium concentration was calculated in 67 serum samples from healthy subjects and 34 outpatients previously identified as having abnormal serum calcium levels. The correlation coefficient between our method (y) and the calcium-ion-selective electrode method (x) was 0.953 and the linear regression equation was y = 0.97x at pH 7.4 with a factor of α = 0.21, which was based on the differences between the concentrations of calcium phosphorus compounds obtained by the electrode method and by calculation. The developed calculation is as useful and accurate as the electrode method, and therefore extremely useful for clinical diagnoses.