Norishige Ehara

Correlation of CT values, iodine concentration, and histological changes in the thyroid.

PURPOSE We have reported that in the thyroid, there is a linear correlation between iodine concentrations and CT values. However, the slope of the regression line was about three times as large as that in KI solutions. We investigated the factor(s) contributing to the increment of the slope of the regression line in the thyroid. METHOD Solutions of NH4I and thyroid hormones were used to investigate the regression line. Thirty-six thyroids were evaluated to investigate the correlation between the iodine concentrations and the area ratio of thyroid follicles, which were measured by preoperative CT and from tissue slices, respectively. RESULTS The slopes of the regression lines in the solutions were almost identical to those in KI solutions. In the thyroid, iodine concentrations were logarithmically correlated with the area ratio of follicles. CONCLUSION The decrease in CT values not only revealed a decrease of iodine concentration in the thyroid but also represented an increase of follicular cells and/or interstitial structures in the volume ratio secondary to it.

Microcalcifications of Breast Tissue: Appearance on Synchrotron Radiation Imaging with 6-μm Resolution

OBJECTIVE The purpose of this study was to use synchrotron radiation imaging with 6-microm resolution to evaluate amorphous and pleomorphic breast tissue microcalcifications. CONCLUSION Synchrotron radiation imaging depicted microcalcifications as small as 24 microm. Imaging with this technique revealed that most amorphous and pleomorphic calcifications on conventional mammograms are clusters of fine specks and that in addition to the shape or density of a speck, the distribution density of clustered specks is a factor determining the apparent shape.

Sensitive detection of voids in solid materials by refraction-enhanced synchrotron radiation imaging

Voids in opaque materials (minute air bubbles) were imaged with synchrotron radiation in a refraction enhancement mode. The voids are imaged by an enhanced x-ray intensity inside the bubble, surrounded by a border region with decreased x-ray intensity, thus allowing sensitive detection of air bubbles in plastic materials. As those “impurities” could not be depicted with conventional radiography, and optical inspection is not useful if the matrix is opaque, this in-situ imaging technique offers the potential to obtain information of air inclusions, voids, and cracking that appear inadvertently in opaque plastics and possibly in metals as well.

Microcalcification detection in synchrotron radiation imaging with refraction-enhancement mode: higher sensitivity through contrast increase

New finding in this study is a contrast enhancement of microcalcifications in a synchrotron radiation image with refraction mode. The contrast enhancement has obviously a greater contribution than edge enhancement to high sensitivity in detecting microcalcifications in synchrotron radiation image with refraction mode