We introduced a method for producing solid phantoms with various water-to-lipid ratios that can simulate the absorption, and to some extent the scattering characteristics of human breast tissue. We also achieved phantom stability for a minimum of one month by solidifying the emulsion phantoms. The characteristics of the phantoms were evaluated using the six-wavelength time-domain diffuse optical spectroscopy (TD-DOS) system we developed to measure water and lipid contents and hemoglobin concentration. The TD-DOS measurements were validated with a magnetic resonance imaging system.

Patients with bacterial endocarditis often have renal complications. This report presents the case of an elderly man with rapidly progressive glomerulonephritis (RPGN) associated with subacute bacterial endocarditis (SBE) due to Enterococcus faecalis infection. The patient was positive for anti-proteinase 3-antineutrophil cytoplasmic antibody (PR3-ANCA) and rheumatoid factor (RF) with hypocomplementemia. Treatment for SBE with antibiotics and the surgical replacement of the affected valves resulted in an improvement of RPGN, the disappearance of PR3-ANCA and RF, and the normalization of hypocomplementemia. This rare case suggests the importance of recognizing the cause of positive PR3-ANCA, because SBE could be an occult cause of RPGN mimicking ANCA-associated vasculitis.

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We previously compared time-domain diffuse optical spectroscopy (TD-DOS) with magnetic resonance imaging (MRI) using various water/lipid phantoms. However, it is difficult to conduct similar comparisons in the breast, because of measurement differences due to modality-dependent differences in posture. Dual-energy computed tomography (DECT) examination is performed in the same supine position as a TD-DOS measurement. Therefore, we first verified the accuracy of the measured fat fraction of fibroglandular tissue in the normal breast on DECT by comparing it with MRI in breast cancer patients (n = 28). Then, we compared lipid and water signals obtained in TD-DOS and DECT from normal and tumor-tissue regions (n = 16). The TD-DOS breast measurements were carried out using reflectance geometry with a source-detector separation of 3 cm. A semicircular region of interest (ROI), with a transverse diameter of 3 cm and a depth of 2 cm that included the breast surface, was set on the DECT image. Although the measurement area differed between the modalities, the correlation coefficients of lipid and water signals between TD-DOS and DECT were rs = 0.58 (p < 0.01) and rs = 0.90 (p < 0.01), respectively. These results indicate that TD-DOS captures the characteristics of the lipid and water contents of the breast.The validity of NIRS systems has generally been verified using tissue simulating phantoms such as intralipid-based aqueous phantoms [8,9] and resin-based hard phantoms [10], while phantoms with various lipid and water contents have been proposed in previous studies [11][12][13][14]. Merrit et al. and Ohmae et al. used such phantoms to compare lipid and water measurements between a diffuse optical spectroscopy (DOS) system and magnetic resonance imaging (MRI), which was defined as the "gold standard" technique [11,14]. In those studies, the authors confirmed that MRI and DOS measurements of water/lipid ratios in phantoms were almost identical. Studies using breast phantoms [13] and simulations [15] have also been conducted, but the structure of the living body is more complicated. Several studies have reported on the relationship between DOS parameters and breast density on MRI and their link with breast cancer risk [3,16,17]. Although previous studies have compared DOS with other modalities such as MRI, there have been no reports comparing DOS with other modalities in the direct measurement of lipid and water signals in the human breast. Although we previously compared lipid and water measurements of the contents of a phantom between MRI and time-domain diffuse optical spectroscopy (TD-DOS) [14], comparison of these parameters in living humans is difficult, because the measurement postures required in the two modalities differ: MRI measurement is conducted with the subject in a prone (downward facing) position, while the subject is generally in a supine (upward facing) or standing position for the DOS measurement.Computed tomography (CT) is a cross-sectional, high-resolution, three-dimensional diagnostic imaging modality ...

To overcome the problems associated with sheet- or film-type anti-adhesive materials, we developed a new type of anti-adhesive material, gelatin flakes. We made two types of gelatin flakes with or without thermal cross-linking, and preliminarily examined their basic properties and the anti-adhesive efficacy using a rodent adhesion model. Both types of the gelatin flakes rapidly turned into gel and tightly attached the injured surfaces, absorbing the moisture and blood, when applied onto the abraded sites of rats. In addition, these flakes could be sprayed into the desired area by compressed air through a device with a long, thin tube, which could be used in laparoscopic surgery. The anti-adhesive effects of both types of gelatin flakes were similar, and both types were significantly superior compared to the non-treated group. Although further investigations are necessary, the gelatin flakes have unique and useful properties and satisfactory anti-adhesive effects, which indicate that they may be applicable in laparoscopic surgery.