[Evaluation of potentially influential factors for positron emission tomography image quality in liver signal-to-noise ratio utilizing a delivery ¹8F-fluoro-2-deoxy-D-glucose study on Bi4Ge3O12-positron emission tomography/computed tomography].

UNLABELLED: The purpose of this study was to evaluate the relationship of body habitus, blood glucose level and injected dose, respectively, with BGO (Bi4Ge3O12) positron emission tomography (PET) image quality using commercially available 2-deoxy-2-[¹8F] fluoro-D-glucose (FDG). We also evaluated the relationship between PET image quality and acquisition time for each weight group. METHOD: One hundred twenty-five patients (66 male, 59 female) were enrolled in the study. We adopted liver signal-to-noise ratio (liver SNR) as an image quality index, derived from the region of interest (ROI) placed on the axial image of the liver. RESULTS: The correlation coefficient between liver SNR and dose per weight was 0.502. The liver SNR indicated a negative relationship with body weight, body mass index (BMI) and cross sectional area of the patient's body, with the correlation coefficients of -0.594, -0.479 and -0.522, respectively. For all weight groups, an extended acquisition time of at least 60 s/bed was necessary to improve liver SNR. CONCLUSION: The findings of this study are potentially of use for designing imaging protocols for the BGO-PET/CT system when using commercially available FDG. It is easy to obtain good image quality for patients of low to average body size with the standard injection dose. However, large patients should be injected, wherever possible, with an FDG dose of up to 5 MBq/kg. The acquisition time in overweight and obese patients should be as longer as possible than in standard weight patients.

[Usefulness of subtraction computed tomography angiography employing orbital synchronized helical scanning for diagnosis of lower extremity arteries with vessel wall calcification].

PURPOSE: Massive calcification complicates the diagnosis of the blood vessel lumen in computed tomography angiography (CTA) of the arteries of the lower extremities. The purpose of this study was to evaluate subtraction CTA with the use of orbital synchronized helical scanning (OS-SCTA). METHOD: Phantom study: We performed OS-SCTA and non-OSCTA of a calcified vessel phantom (ψ2.5 mm), and compared them with a non-calcified vessel phantom as the reference by full width at half maximum (FWHM) and full width at tenth maximum (FWTM) of maximum intensity projection (MIP) images. Clinical study: 58 patients with peripheral artery disease who were referred for angiography also underwent OS-SCTA. OS-SCTA was produced using MIP images. Findings were graded according to three categories: (1) stenosis greater than 50% or occluded; (2) stenosis less than 50%; (3) not detected due to insufficient image quality. OS-SCTA findings were compared with the angiographic findings for each arterial segment. RESULTS: In the phantom study, FWHM showed no significant difference between OS-SCTA and the reference (P=0.135), whereas FWTM showed a significant difference (P<0.001). FWHM and FWTM showed a significant difference between non-OS-SCTA and the reference (P<0.001), due to misregistration with helical artifacts. In a clinical study comparing OS-SCTA with angiography, the sensitivity and specificity were 93.3% and 95.1% in calcified segments, 91.8% and 93.9% in non-calcified segments, and 92.2% and 94.6% in all segments. There was no significant difference between calcified segments and non-calcified segments (sensitivity: P=0.568, specificity: P=0.549). CONCLUSION: OS-SCTA is beneficial for the diagnosis of lower extremity arteries with vessel wall calcification, since it shows detection accuracy comparable to that of angiography.

Relationships among blood leptin and adiponectin levels, fat mass, and bone mineral density in Japanese pre- and postmenopausal women.

We conducted a survey of 111 healthy middle-aged and older women, aged 40 to 80 years, to elucidate the relationships between blood leptin and adiponectin levels and bone mineral density (BMD) in September 2008. We examined the associations between the blood levels of these adipocytokines and the lumbar spine (L2-L4), left femoral, and distal forearm BMD after adjustment for the age and body fat percentage. No correlation was observed between leptin and the BMD. This is presumably due to the fact that the influence of menopause, age, duration of postmenopausal period, and body fat percentage on the BMD is greater than that of leptin levels in healthy women. The adiponectin levels were significantly correlated negatively with the lumbar spine and femoral BMD in premenopausal women, and with forearm BMD in postmenopausal women, regardless of adjustment for age and body fat percentage. It seems likely that adiponectin influences the BMD at different skeletal sites in pre- and postmenopausal women.

Evaluation of osteoporosis in X-ray CT examination: a preliminary study for an automatic recognition algorithm for the central part of a vertebral body using abdominal X-ray CT images.

We have developed an algorithm that can distinguish the central part of the vertebral body from abdominal X-ray CT images to determine whether it is possible to aid a diagnosis of osteoporosis. We classified three measures for the principal component analysis and linear discriminant function. When we judged whether patients had osteoporosis or not, the ratio usable for diagnosing osteoporosis (sensitivity) was 1.00 (15/15), and for diagnosing as normal (specificity) was 0.64 (7/11). We believe that this algorithm can be used to aid in diagnosing osteoporosis, utilizing the measures obtained from the CT images.

[Effect of variation of lemon intake and walking in daily life on various indicators of muscle mass and blood biochemistry in menopausal middle-aged and elderly women].

OBJECTIVES: We examined the factors considered to change body composition and blood biochemistry indicators in menopausal middle-aged and elderly women. These changes result from exercise by walking as part of their daily activities and lemon consumption by women who live on the small islands of the Seto Inland Sea, Japan's largest citrus fruit (lemon)-producing region. METHODS: Between September 2011 and March 2012, we recorded the daily lemon consumption and the number of steps taken by 101 middle-aged and elderly female lemon farmers. We also measured their body dimensions, body compositions, and blood pressure pulse wave velocity and conducted blood tests before and after the survey period. The results before and after the survey period were compared by the t-test and associations were determined on the basis of Pearson's correlation coefficient. Covariance structural analysis was carried out to determine causal associations. RESULTS: From the results of covariance structure analysis, lemon intake did not have a direct impact on each item examined. The third item, i.e., "the factors related to arteriosclerosis," was affected indirectly via citric acid and fatigue, and anticoagulation was shown. The fourth item, i.e., "the factors related to maintenance of muscle mass," which is affected by menopausal years and the change in walking speed, was shown to be associated with the second item, i.e., "the factors related to lipid metabolism." Menopausal years affected the first, third and fourth items. CONCLUSIONS: Lemon intake did not have a direct impact on each item. Lemon has been shown to indirectly affect the third item through citric acid. Walking affected the second item, the level of total cholesterol, such as HDL cholesterol, through the fourth item. The importance of providing services that lead to sustained physical activity and a well-balanced metabolism between lipids and carbohydrates has been shown.