Echocardiographic score for the screening of cardiac amyloidosis with positive 99m technetium pyrophosphate scintigraphy result.

INTRODUCTION: Speckle-tracking-derived strains in cardiac chambers may provide better solutions for transthyretin amyloid cardiomyopathy (ATTR-CM) screening. This study aimed to evaluate the efficacy of biventricular strain measurements using speckle tracking for screening 99m Tc-pyrophosphate (99m Tc-PYP) scintigraphy-positive cardiomyopathy, which is nearly equivalent to ATTR-CM. METHODS: We performed a retrospective analysis of transthoracic echocardiographic studies using vendor-independent speckle tracking analysis in older patients (≥65 years) who underwent 99m Tc-PYP scintigraphy to evaluate the etiology of suspected ATTR-CM in our institute between January 2019 and December 2022. RESULTS: The entire cohort (n = 89) was divided into two subgroups positive 99m Tc-PYP scan results (n = 34) and negative 99m Tc-PYP scan results (n = 55). In the multivariate analysis, posterior wall thickness (p = .003, odds ratio [OR]:1.48, 95% confidence interval [CI]:1.14 -1.92), left ventricular longitudinal strain apical/basal ratio (LVLSapi/bas) (p = .015, OR: 2.78, 95% CI: 1.23-6.32, and right ventricular longitudinal strain (RVLS) (p = .003, OR: 1.15, 95% CI: 1.05 -1.26) were selected to be the most representative echocardiographic findings in 99m Tc-PYP positive cardiomyopathy. The receiver operating characteristic analysis indicated that posterior wall thickness (p < .0001, area under the curve [AUC]: .821, cut-off value: 14.0 mm), LVLSapi/bas (p < .001, AUC: .802, cut-off value: 2,16), and RVLS (p < .001, AUC: .791, cut-off value: -18.7%) could significantly detect 99m Tc-PYP positive results with an excellent credibility. Echocardiographic score points calculated using the summary of these three parameters in each patient revealed that a 2-point score had a fair sensitivity (85%) and an excellent specificity (93%), while a 1-point score had an excellent sensitivity (91%) and a modest specificity (53%). CONCLUSION: Our proposed echocardiographic screening tool for 99m Tc-PYP scintigraphy-positive cardiomyopathy may help clinicians manage patients with suspected ATTR-CM.

Current situations and discussions in Japan in relation to the new occupational equivalent dose limit for the lens of the eye.

Since the International Commission on Radiological Protection recommended reducing the occupational equivalent dose limit for the lens of the eye in 2011, there have been extensive discussions in various countries. This paper reviews the current situation in radiation protection of the ocular lens and the discussions on the potential impact of the new lens dose limit in Japan. Topics include historical changes to the lens dose limit, the current situation with occupational lens exposures (e.g., in medical workers, nuclear workers, and Fukushima nuclear power plant workers) and measurements, and the current status of biological studies and epidemiological studies on radiation cataracts. Our focus is on the situation in Japan, but we believe such information sharing will be useful in many other countries.

Verification of screening level for decontamination implemented after Fukushima nuclear accident.

The screening level for decontamination that has been applied for the surface of the human body and contaminated handled objects after the Fukushima nuclear accident was verified by assessing the doses that arise from external irradiation, ingestion, inhalation and skin contamination. The result shows that the annual effective dose that arises from handled objects contaminated with the screening level for decontamination (i.e. 100 000 counts per minute) is <1 mSv y(-1), which can be considered as the intervention exemption level in accordance with the International Commission on Radiological Protection recommendations. Furthermore, the screening level is also found to protect the skin from the incidence of a deterministic effect because the absorbed dose of the skin that arises from direct deposition on the surface of the human body is calculated to be lower than the threshold of the deterministic effect assuming a practical exposure duration.