[Impact of Residual Radioactivity Rate of 99mTc-macro Aggregated Albumin (MAA) in Syringes and Administration Routes with a Focus on Pediatric Nuclear Medicine Examinations].

PURPOSE: The purpose of this study was to evaluate the residual radioactivity in the syringe and route of administration of a low fluid volume 99mTc-macro aggregated albumin (MAA) intended for pediatric nuclear medicine examinations. METHOD: We evaluated the residual characteristics, as the effect of elapsed time from drawing up of radiopharmaceuticals to plastic syringe to administration, and the effect of volume of 99mTcO4- solution to be labeled, the effect of rinsed times of plastic syringe, effect of dose of calculated by consensus guidelines for pediatric nuclear medicine and residual location in injection sets with 99mTc-MAA. Residual radioactivity was measured using planar images obtained by the gamma camera. RESULTS: Residual radioactivity rate of 99mTc-MAA, 99mTc-MAG3, 123I-IMP showed 41.3±1.6%, 14.4±0.6%, 14.6±2.0%, respectively. 99mTc-MAA clearly showed a higher residual rate. Residual radioactivity rate increased with the extension of the elapsed time, and reached a high value of 41.3% in 30 minutes. Residual radioactivity rate was dependent on the different volume of 99mTcO4- to be labeled (4.0 ml and 8.0 ml). Residual radioactivity rate did not change when the number of rinsed was more than one. Residual rate was around 40% at all doses of calculated by consensus guidelines for pediatric nuclear medicine. CONCLUSION: 99mTc-MAA showed the highest residual radioactivity rate among radiopharmaceuticals used in pediatric nuclear medicine examinations. The factor that most affected the residual radioactivity rate of 99mTc-MAA was the elapsed time from draw up to the plastic syringe to administration.

[Improvement of Standardized Uptake Value Accuracy in the 99mTc Body SPECT and SPECT/CT: Optimization of the Phantom for Calculating Becquerel Calibration Factor and Correction Method].

PURPOSE: The purpose of this study was to evaluate the best phantom for calculating the becquerel calibration factor (BCF) and correction method to obtain the improvement of standardized uptake value (SUV) accuracy in both single photon emission computed tomography (SPECT) and SPECT/CT. METHOD: A SPECT/CT scanner was used in this study. BCFs were calculated using four phantoms with different cross sections including National Electrical Manufacturers Association International Electrotechnical Commission body phantom (NEMA IEC body phantom) filled with 99mTcO4-, and five correction methods were used for reconstruction. SUVs were calculated by the NEMA IEC body phantom and pediatric phantom in house with these BCFs. We then measured SUVmean in the background region of the NEMA IEC body phantom, SUVmax and SUVpeak of the 37-mm-diameter sphere. RESULTS: In the SPECT scanner, SUVmean and SUVmax measured 1.04 and 4.02, respectively, in the case of BCF calculation and SUV measurement using NEMA IEC body phantoms without corrections. In the SPECT/CT scanner, SUVmean with CT attenuation correction (AC) was in agreement with the theoretical values using each phantom. SUVmax showed the same trend. CONCLUSION: In the SPECT scanner, it is possible to obtain a highly accurate SUV by using a phantom that matches the size of the subject for BCF calculation and without correction. In the SPECT/CT scanner, highly accurate SUVs can be obtained by using CT-based attenuation correction, and these values do not depend on the size of the BCF calculation phantom.

Relationship between transient severe motion of the liver in gadoxetic acid or iodinated contrast agent-enhanced imaging and arterial oxygen saturation and heart rate changes.

PURPOSE: To clarify the relationship between transient sever motion artifact in arterial phase (TSMA) and changes in peripheral capillary oxygen saturation (SpO2) and heart rate (HR) after contrast media administration during MRI or CT of the liver. METHODS: 87 patients undergoing 61 MRI examination with gadoxetic acid or 26 CT examination with iodinated contrast were included. Dynamic contrast-enhanced imaging (DCEI) was obtained at four vascular phase acquisitions. Reviewers extracted the segmental data of SpO2 and HR in each phase from consecutive data in DCE-CT or DCE-MRI. In addition, reviewers scored for respiratory motion in each phase using 5-point scale. Patients with an arterial score of 4-5, and other phase scores of 1-2 were considered to be exhibiting TSMA. RESULTS: In gadoxetic acid, mean SpO2 of arterial phase was significantly lower than three other phases (P = 0.045 to P < 0.001). However, the decrease in SpO2 in arterial phase compared with other phases was <1%. Mean HR in gadoxetic acid or iodinated contrast agent was highest in the portal-phase. The incidence of TSM was 0% in patients with iodinated contrast agent and was 8.2% (5/61 patients; TSM group) in patients with gadoxetic acid, respectively. In addition, there was no significant difference in mean SpO2 of arterial phase between the TSM group (97.5% ±â€¯1.08%) and non-TSM group (96.4% ±â€¯1.85%) (P = 0.219). CONCLUSION: The slight decrease in SpO2 in arterial phase is not associated with TSMA.

Software for the data analysis of the arrival-timing monitor at SACLA.

X-ray free-electron laser (XFEL) pulses from SPring-8 Ångstrom Compact free-electron LAser (SACLA) with a temporal duration of <10 fs have provided a variety of benefits in scientific research. In a previous study, an arrival-timing monitor was developed to improve the temporal resolution in pump-probe experiments at beamline 3 by rearranging data in the order of the arrival-timing jitter between the XFEL and the synchronized optical laser pulses. This paper presents Timing Monitor Analyzer (TMA), a software package by which users can conveniently obtain arrival-timing data in the analysis environment at SACLA. The package is composed of offline tools that pull stored data from cache storage, and online tools that pull data from a data-handling server in semi-real time during beam time. Users can select the most suitable tool for their purpose, and share the results through a network connection between the offline and online analysis environments.

Data acquisition system for X-ray free-electron laser experiments at SACLA.

A data acquisition system for X-ray free-electron laser experiments at SACLA has been developed. The system has been designed for reliable shot-to-shot data storage with a high data stream greater than 4 Gbps and massive data analysis. Configuration of the system and examples of prompt data analysis during experiments are presented. Upgrade plans for the system to extend flexibility are described.

Renal corticomedullary differentiation by non-contrast-enhanced MR imaging with a spatially selective IR pulse at various inversion times: comparison with fast asymmetric spin echo (FASE) and steady-state free-precession (SSFP).

We compared visualization of corticomedullary differentiation between fast asymmetric spin echo (FASE) and steady-state free precession (SSFP) combined with spatially selective inversion recovery (IR) pulse and optimal inversion time (TI). Though the corticomedullary contrast ratio was higher in FASE than SSFP images, visualization of corticomedullary differentiation was significantly better in SSFP images than FASE images obtained with spatially selective IR pulses and optimal TI.

Accumulation of gamma-aminobutyrate (GABA) caused by heat-drying and expression of related genes in immature vegetable soybean (edamame).

We studied the effects of drying of immature seeds of vegetable soybean (Glycine max L. Merrill) on the accumulation of gamma-aminobutyrate (GABA) in the seeds. GABA accumulated after heat-drying, with the maximum at 40°C. The GABA content (447.5 mg/100 g DW) increased to more than 5 times the value in untreated seeds (79.6 mg/100 g DW). In contrast, the glutamate content decreased rapidly to 1/3 the level in the untreated seeds. The GABA content increased early in the heat-drying treatment: after 30 min, it had increased to 1.5 times the value in the untreated seeds. GABA did not accumulate in the vacuum-drying treatment. Among genes related to the GABA shunt, the gene for glutamate decarboxylase (EC 4.1.1.15), which catalyzes the decarboxylation of glutamate to produce GABA, showed relatively high expression, decreasing to only 70% of the value in untreated seeds even after 4 h of treatment. In contrast, expression of the genes for two catabolic mitochondrial enzymes, GABA transaminase (GABA-T; EC 2.6.1.19) and succinate semialdehyde dehydrogenase (SSADH; EC 1.2.1.16), decreased rapidly during heat-drying. These results suggest that the accumulated GABA was not metabolized rapidly by GABA-T and SSADH and therefore remained at high levels.

Effectiveness of minocycline-based triple therapy for eradication of Helicobacter pylori infection.

BACKGROUND: Widespread use of eradication therapy for Helicobacter pylori has increased the prevalence of clarithromycin-resistant strains. The purpose of the present paper was to measure the in vitro antibacterial activity of minocycline against H. pylori, and study the effectiveness of minocycline-based first- and second-line eradication therapies. METHODS: For first-line therapy, 79 patients were randomly assigned to the treatment with rabeprazole, amoxicillin, and clarithromycin or with rabeprazole, amoxicillin, and minocycline. For second-line therapy, 88 patients were tested for sensitivity to metronidazole: 67 patients with metronidazole-sensitive strains received a 7-day course of rabeprazole, minocycline, and metronidazole; the remaining 21 patients were given a 7-day course of rabeprazole, minocycline, and faropenem. RESULTS: There was virtually no resistance to minocycline among the strains tested. The eradication rate of H. pylori infection in first-line therapy was significantly lower for minocycline-containing regimen (38.5%, 15/39) than for clarithromycin-containing regimen (82.5%, 33/40; P < 0.01). For second-line therapy, a high eradication rate against metronidazole-sensitive strains was obtained with rabeprazole, minocycline and metronidazole (85%, 57/67). CONCLUSIONS: A combination of rabeprazole, minocycline, and metronidazole is safe and effective for second-line therapy of H. pylori infection. Because this regimen can be administered to patients with penicillin allergy and patients who suffer adverse reactions to amoxicillin, such as diarrhea and other digestive symptoms, it should be considered useful for second- and third-line eradication therapy.