Assessment of first-time and repeated acute adverse reactions to gadolinium-based contrast agents in MRI: A retrospective study.

PURPOSE: To identify gadolinium-based contrast agents (GBCAs)-related and patient-related risk factors for acute adverse reactions (AARs), and to examine the incidence and severity of repeated AARs. METHODS: This study retrospectively evaluated all intravenous GBCA injections in MRI studies at a single institution from January 2012 to September 2019. First-time AARs in patients without a past history of AARs and risk factors were assessed using multivariable regression models with generalized estimating equations. For patients with a past history of AAR(s), we evaluated the incidence of repeated AARs using the Fisher's exact test, as well as the severity of these repeated AARs. RESULTS: First-time AARs occurred in 129 of 41,827 GBCA injections (0.31 %; 0.70 % of 18,431 patients). With gadoterate meglumine as the reference, the odds ratio (OR) for allergic-like reactions to three GBCAs ranged from 3.27 to 8.03 (p = 0.012 to <0.001). For chemotoxic reactions, the OR was 3.75 (p = 0.001) for gadoteridol. Outpatients had a lower OR for chemotoxic reactions, while higher ORs were observed in head/neck and breast MRI (p < 0.05). The OR for age was 0.99 (p < 0.05). Patients with a past history of AAR(s) had a 3.6 % incidence of mild repeated AARs for all GBCA, significantly higher than the 0.31 % in first-time AARs (p < 0.001). No effectiveness was found for steroid premedication. CONCLUSION: The occurrence of first-time AARs was related to the GBCA used and other factors. The incidence of repeated AARs was higher than first-time AARs, though all were mild in severity.

Evaluation of bone marrow invasion on the machine learning of 18 F-FDG PET texture analysis in lower gingival squamous cell carcinoma.

OBJECTIVES: Lower gingival squamous cell carcinoma (LGSCC) has the potential to invade the alveolar bone. Traditionally, the diagnosis of LGSCC relied on morphological imaging, but inconsistencies between these assessments and surgical findings have been observed. This study aimed to assess the correlation between LGSCC bone marrow invasion and PET texture features and to enhance diagnostic accuracy by using machine learning. METHODS: A retrospective analysis of 159 LGSCC patients with pretreatment 18 F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) examination from 2009 to 2017 was performed. We extracted radiomic features from the PET images, focusing on pathologic bone marrow invasion detection. Extracted features underwent the least absolute shrinkage and selection operator algorithm-based selection and were then used for machine learning via the XGBoost package to distinguish bone marrow invasion presence. Receiver operating characteristic curve analysis was performed. RESULTS: From the 159 patients, 88 qualified for further analysis (59 men; average age, 69.2 years), and pathologic bone marrow invasion was identified in 69 (78%) of these patients. Three significant radiological features were identified: Gray level co-occurrence matrix_Correlation, INTENSITY-BASED_IntensityInterquartileRange, and MORPHOLOGICAL_SurfaceToVolumeRatio. An XGBoost machine-learning model, using PET radiomic features to detect bone marrow invasion, yielded an area under the curve value of 0.83. CONCLUSION: Our findings highlighted the potential of 18 F-FDG PET radiomic features, combined with machine learning, as a promising avenue for improving LGSCC diagnosis and treatment. Using 18 F-FDG PET texture features may provide a robust and accurate method for determining the presence or absence of bone marrow invasion in LGSCC patients.

Clinical features and risk factors of iodinated contrast media (ICM)-induced anaphylaxis.

PURPOSE: To evaluate the clinical features and risk factors of iodinated contrast media (ICM)-induced anaphylaxis. METHODS: This retrospective study included all patients undergoing contrast-enhanced computed tomography (CT) with intravenous ICM administration (iopamidol, iohexol, iomeprol, iopromide, ioversol) at our hospital between April 2016 and September 2021. Medical records of patients who experienced anaphylaxis were reviewed, and the multivariable regression model using generalized estimating equations was employed to eliminate the effect of intrapatient correlation. RESULTS: Of the 76,194 ICM administrations (44,099 men [58 %] and 32,095 women; age, median, 68 years) to 27, 696 patients, anaphylaxis occurred in 45 cases in 45 different patients (0.06 % of administration and 0.16 % of patients), all with onset within 30 min after administration. Thirty-one (69 %) had no risk factors for ADRs, including 14 (31 %) who had previously used the same ICM that caused anaphylaxis. Thirty-one patients (69 %) had a history of ICM use without any ADRs. Four patients (8.9 %) received oral steroid premedication. The only factor associated with anaphylaxis was the type of ICM, with an odds ratio (OR) of 6.8 (p < 0.001) for iomeprol with iopamidol as a reference. No significant differences in OR of anaphylaxis were found for patients' age, sex, or premedication. CONCLUSION: The overall incidence of anaphylaxis due to ICM was very low. More than half of the cases had no risk factors for ADRs and had no ADRs on past ICM administration, although the ICM type was associated with a higher OR.

Contrast-induced anaphylaxis: does it occur in the medical environment and is it being responded to appropriately?

PURPOSE: To analyze the appropriateness of primary response for anaphylaxis due to iodinated contrast media (ICM) or gadolinium-based contrast agents (GBCA). MATERIALS AND METHODS: This retrospective study included all patients in whom intravenous contrast agents (five types of ICMs and four types of GBCAs) were administered at our hospital between April 2016 and September 2021. For the patients who developed anaphylaxis, we obtained data on the time records of contrast injection, anaphylaxis onset, and intramuscular adrenaline (epinephrine) administration. RESULTS: Of the 76,555 ICM and 30,731 GBCA administrations, anaphylaxis occurred in 49 cases (0.05%), and in 48 cases (98.0%) the onset was within 30 min after administration with widely distributed times (median, 7.5 min; interquartile range, 4.5-10.8 min; max, 26 min). Intramuscular adrenaline administration was performed in 43 cases (87.8%), and this was done within five minutes after the onset in 37 cases (75.5%). Only in 24 cases (49.0%), there were time records of both the onset and adrenaline administration (if performed). CONCLUSION: Anaphylaxis occurred within 30 min after contrast injection in the majority of the cases, but times were widely distributed. Only in 75.5% of cases, appropriate primary treatment was performed, and the importance of keeping exact time records in patients' charts should be re-emphasized.

Biomarkers Predictive of Distant Disease-free Survival Derived from Diffusion-weighted Imaging of Breast Cancer.

PURPOSE: To investigate whether intravoxel incoherent motion (IVIM) and/or non-Gaussian diffusion parameters are associated with distant disease-free survival (DDFS) in patients with invasive breast cancer. METHODS: From May 2013 to March 2015, 101 patients (mean age 60.0, range 28-88) with invasive breast cancer were evaluated prospectively. IVIM parameters (flowing blood volume fraction [fIVIM] and pseudodiffusion coefficient [D*]) and non-Gaussian diffusion parameters (theoretical apparent diffusion coefficient [ADC] at a b value of 0 s/mm2 [ADC0] and kurtosis [K]) were estimated using a diffusion-weighted imaging series of 16 b values up to 2500 s/mm2. Shifted ADC values (sADC200-1500) and standard ADC values (ADC0-800) were also calculated. The Kaplan-Meier method was used to generate survival analyses for DDFS, which were compared using the log-rank test. Univariable Cox proportional hazards models were used to assess any associations between each parameter and distant metastasis-free survival. RESULTS: The median observation period was 80 months (range, 35-92 months). Among the 101 patients, 12 (11.9%) developed distant metastasis, with a median time to metastasis of 79 months (range, 10-92 months). Kaplan-Meier analysis showed that DDFS was significantly shorter in patients with K > 0.98 than in those with K ≤ 0.98 (P = 0.04). Cox regression analysis showed a marginal statistical association between K and distant metastasis-free survival (P = 0.05). CONCLUSION: Non-Gaussian diffusion may be associated with prognosis in invasive breast cancer. A higher K may be a marker to help identify patients at an elevated risk of distant metastasis, which could guide subsequent treatment.

The dependence of acetylcholine on dynamic changes in the membrane potential and an action potential during spike timing-dependent plasticity induction in the hippocampus.

The hippocampus is an important area for memory encoding and retrieval and is the location of spike timing-dependent plasticity (STDP), a basic phenomenon of learning and memory. STDP is facilitated if acetylcholine (ACh) is released from cholinergic neurons during attentional processes. However, it is unclear how ACh influences postsynaptic changes during STDP induction and determines the STDP magnitude. To address these issues, we obtained patch clamp recordings from CA1 pyramidal neurons to evaluate the postsynaptic changes during stimuli injection in Schaffer collaterals by quantifying baseline amplitudes (i.e., the lowest values elicited by paired pulses comprising STDP stimuli) and action potentials. The results showed that baseline amplitudes were elevated if eserine was applied in the presence of picrotoxin. In addition, muscarinic ACh receptors (mAChRs) contributed more to the baseline amplitude elevation than nicotinic AChRs (nAChRs). Moreover, the magnitude of the STDP depended on the magnitude of the baseline amplitude. However, in the absence of picrotoxin, baseline amplitudes were balanced, regardless of the ACh concentration, resulting in a similar magnitude of the STDP, except under the nAChR alone-activated condition, which showed a larger STDP and lower baseline amplitude induction. This was due to broadened widths of action potentials. These results suggest that activation of mAChRs and nAChRs, which are effective for baseline amplitudes and action potentials, respectively, plays an important role in postsynaptic changes during memory consolidation.

[Evaluation of the Effect of Tube Voltage on Metal Artifact Reduction in Cone Beam Computed Tomography].

The purpose of this study was to evaluate the effectiveness of metal artifact reduction (MAR) processing in cone beam computed tomography angiography using the relative artifact index (AIr) and the difference due to tube voltage. A water phantom was imaged to obtain noise images. Next, a platinum alloy embolic coil was installed in the central part of the water phantom and the peripheral part, and then artifact images were acquired. The tube voltages were 70 kV and 109 kV, and four types of artifact images were acquired (with and without MAR). In all, 10 images in the z-direction from each image series were acquired (total: 40 images). The AIr value was calculated by setting a region of interest in the images, and multiple comparisons were made between the imaging conditions (significance level set at p<0.05). The AIr values were significantly lower by MAR, and MAR significantly reduced metal artifacts regardless of tube voltage (p<0.001). This study's results show that MAR with cone beam CT can reduce metal artifacts by more than 91%, and the effect is comparable regardless of tube voltage.

Quantitative assessment of chest compression techniques on an infant manikin.

BACKGROUND: Current cardiopulmonary resuscitation (CPR) guidelines recommend the two-finger technique (TFT) of chest compression (CC) in infants for a single rescuer. We hypothesized that healthcare providers cannot achieve adequate CC depth with TFT, even if using real-time visual feedback (RVF). METHODS: This was a cross-over study, randomizing participants to perform three sets of 2-min continuous CC, comparing (i) TFT with RVF, (ii) the one-hand technique (OHT) without RVF, and (iii) OHT with RVF. A standard CPR trainer manikin of a 3-month-old infant and a monitor/defibrillator that displays and records the quantitative CC quality were used. We set a target compression depth of 40-50 mm and a target compression rate of 100-120/min. Data were analyzed using the Friedman test and Bonferroni correction. Statistical significance was defined as P-value of< 0.05. RESULTS: Fifty-nine healthcare providers participated in the study. The mean compression depth was 24 mm (interquartile range [IQR], 22-26 mm) in TFT with RVF and 43 mm (IQR, 38-48 mm) in OHT without RVF, P < 0.001. The proportion of adequate CC depth was 0% (IQR, 0-0%) in TFT with RVF, 22% (IQR, 5-54%) in OHT without RVF, and 62% (IQR, 29-83%) in OHT with RVF. The mean compression rate was within the target range in all three techniques. CONCLUSIONS: The TFT cannot produce the CC depth that meets the recommendation of the current CPR guidelines for an infant with RVF, whereas the OHT does.

Evaluation of moyamoya disease in CT angiography using ultra-high-resolution computed tomography: Application of deep learning reconstruction.

PURPOSE: The aim of this study was to examine the evaluation of ultra-high-resolution computed tomography angiography (UHR CTA) images in moyamoya disease (MMD) reconstructed with hybrid iterative reconstruction (Hybrid-IR), model-based iterative reconstruction (MBIR), and deep learning reconstruction (DLR). METHODS: This retrospective study with institutional review board approval included patients with clinically suspected MMD who underwent UHR CTA between January 2018 and July 2020. CTA images were reconstructed with three reconstruction methods. Qualitative visualization was evaluated in comparison with digital subtraction angiography. Quantitative evaluation included assessment of edge sharpness, full width at half maximum (FWHM), vessel contrast, and tissue signal-to-noise ratio (SNRtissue). One-way analysis of variance was used to analyze differences. In addition, reconstruction time were assessed. RESULTS: Qualitative evaluation of CTA for 33 sides did not differ significantly between reconstruction methods. In quantitative evaluation for 54 patients, edge sharpness for right and left cortical segments of the middle cerebral artery was significantly higher for Hybrid-IR than for other reconstructions. No significant difference was seen between MBIR and DLR. Edge sharpness for STA-MCA bypass was significantly higher for Hybrid-IR than for MBIR, but no significant difference was seen between Hybrid-IR and DLR. FWHM for STA-MCA showed no significant difference between the three reconstruction methods. DLR displayed the highest SNRtissue. The time required for reconstruction was 40 s for Hybrid-IR, 2580 s for MBIR, and 180 s for DLR. CONCLUSION: UHR CTA with DLR adequately visualized vessels in patients with MMD within a clinically feasible reconstruction time.

Influence of obesity in interstitial lung disease associated with anti-aminoacyl-tRNA synthetase antibodies.

BACKGROUND: Obesity is a major risk factor for developing various respiratory diseases. Patients with anti-aminoacyl tRNA synthetase (ARS) antibodies often have interstitial lung disease (ILD). The present study was conducted to evaluate the association between obesity and outcomes of anti-ARS antibody-related ILD (ARS-ILD). METHODS: We retrospectively investigated 58 patients with ARS-ILD and compared the clinical characteristics, treatment, and prognoses between obese (body mass index [BMI] ≥25 kg/m2) and nonobese (BMI <25 kg/m2) patients. Chest fat was quantified via computed tomography (CT). Thoracic subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were measured at diagnosis and first relapse of ILD. RESULTS: Sixteen patients were obese. Obese patients had lower percentages of predicted diffusing capacity of the lungs for carbon monoxide and higher high-resolution CT scores and SAT and VAT indexes than did nonobese patients. The ILD relapse rate was higher in obese patients (P < 0.01), especially among those with high SAT indexes (P < 0.01). The SAT and VAT indexes increased significantly from diagnosis until first relapse. Among clinical parameters at first relapse, SAT and VAT indexes were correlated with serum Krebs von den Lungen-6 levels (r = 0.720, P = 0.008) and total ground-glass attenuation scores (r = 0.620, P = 0.024), respectively. CONCLUSIONS: Obesity and high SAT indexes are risk factors for ILD relapse in patients positive for anti-ARS antibodies. Evaluating and quantifying patients' chest fat on CT is important for predicting ILD relapse.

Patients' radiation dose in computed tomography-fluoroscopy-guided percutaneous cryoablation for small renal tumors.

PURPOSE: This study aimed to evaluate patients' radiation dose in computed tomography (CT)-fluoroscopy-guided cryoablation for small renal tumors and assess the possible factors affecting it. METHODS: In our institution, cryoablation was performed in 152 patients between 2013 and 2020. Procedures that were not for renal tumors and did not have radiation dose records and detailed information were excluded from the analysis. The size-specific dose estimates (SSDE), volume CT dose index (CTDIvol), dose-length product (DLP), and entrance skin dose (ESD) were evaluated for both spiral scan and CT-fluoroscopy. The effects of the number of cryoneedle punctures; combined use of hydro- and/or pneumodissection procedures; patients' characteristics, such as body-mass index (BMI); and the tumor-related factors, such as tumor location, were determined by the univariate and multivariate analyses. RESULTS: In the 72 included procedures, the median SSDE was 658 mGy and the median CTDIvol was 456 mGy. The median percentage dose of CT-fluoroscopy to the total procedure dose was estimated as 89.8% (591/658 mGy) with SSDE and 41.4% (611/1,475 mGy cm) with DLP. The combined use of hydro- and/or pneumodissection and number of cryoneedle punctures were significantly associated with the total ESD, and the maximum total ESD was 863 mGy in our cases. CONCLUSIONS: Using SSDE as an index, 89.8% of patients' radiation dose was attributed to CT-fluoroscopy, and ESD for the total procedure did not exceed 1 Gy. The increased number of cryoneedle punctures and combined use of hydro- and/or pneumodissection increased the total ESD.

Physiological properties of Cantor coding-like iterated function system in the hippocampal CA1 network.

Cantor coding provides an information coding scheme for temporal sequences of events. In the hippocampal CA3-CA1 network, Cantor coding-like mechanism was observed in pyramidal neurons and the relationship between input pattern and recorded responses could be described as an iterated function system. However, detailed physiological properties of the system in CA1 remain unclear. Here, we performed a detailed analysis of the properties of the system related to the physiological basis of learning and memory. First, we investigated whether the system could be simply based on a series of on-off responses of excitatory postsynaptic potential (EPSP) amplitudes. We applied a series of three spatially distinct input patterns with similar EPSP peak amplitudes. The membrane responses showed significant differences in spatial clustering properties related to the iterated function system. These results suggest that existence of some factors, which do not simply depend on a series of on-off responses but on spatial patterns in the system. Second, to confirm whether the system is dependent on the interval of sequential input, we applied spatiotemporal sequential inputs at several intervals. The optimal interval was 30 ms, similar to the physiological input from CA3 to CA1. Third, we analyzed the inhibitory network dependency of the system. After GABAA receptor blocker (gabazine) application, quality of code discrimination in the system was lower under subthreshold conditions and higher under suprathreshold conditions. These results suggest that the inhibitory network increase the difference between the responses under sub- and suprathreshold conditions. In summary, Cantor coding-like iterated function system appears to be suitable for information expression in relation to learning and memory in CA1 network.

Usefulness of model-based iterative reconstruction in low-dose lumbar spine CT after spine surgery with metal implant: a phantom study.

BACKGROUND: The major problems of computed tomography (CT) imaging include radiation exposure and severe artifacts caused by operative implants. PURPOSE: To evaluate the usefulness of the metal artifact reduction algorithm and model-based iterative reconstruction (MBIR) in postoperative low-dose (LD) spine CT. MATERIAL AND METHODS: A CT torso phantom was scanned at standard-dose (SD) and LD settings. The CT images were reconstructed by three methods: hybrid iterative reconstruction (HIR); metal artifact reduction; and MBIR. The radiation dose of the phantom imaging was evaluated by volume CT dose index (mGy), dose length product (DLP, mGy × cm), and effective dose (mSv). The image quality of the six images was visually evaluated and analyzed using Scheffe's paired comparison method. The average preference of each method was calculated based on the comparative scores. The task transfer function (TTF) and noise power spectrum for HIR and MBIR were also measured. RESULTS: The respective radiation-dose-related parameters of the SD and LD conditions were: volume CT dose index = 10.2 and 1.2 mGy; DLP = 277.9 and 33.9 mGy × cm; and effective dose = 4.2 and 0.5 mSv. The average preference for diagnostic acceptability of MBIR at LD was not significantly different from the other reconstructions of SD data. MBIR successfully reduced metal artifacts in the LD condition. The 10% TTF was higher for HIR at SD and higher for MBIR at LD. CONCLUSION: MBIR is useful for LD spine CT after spine surgery with metal implant.

EVALUATION OF ORGAN DOSE BASED ON PATIENT DATA IN EAST ASIAN DESCENT PEDIATRIC HEAD CT EXAMINATIONS.

The purpose of this study was to investigate other indices estimating absorbed dose for eye lens and brain, using clinical images of East Asian pediatric patients. We simulated head computed tomography (CT ) examinations in 104 pediatric patients. Effective diameter (deff) and water equivalent diameter (dw) were measured on clinical images. Various size metrics and age were compared with absorbed dose normalised by CTDIvol (nD). The nD was estimated for eye and brain. The nD tended to decrease with advancing age. R2 between age and nD were 0.38 and 0.31 for eye and brain, respectively. Increasing head diameters decreased each nD. R2 between deff and dw, and nD were 0.20-0.24 and 0.51-0.53 for eye and brain, respectively. Head sizes allowed us to estimate absorbed dose in brain CT on East Asian pediatric patients. Scanning parameters for pediatric head CT may need to be based on individual patient information.

Cervical spinal computed tomography utilizing model-based iterative reconstruction reduces radiation to an equivalent of three cervical X-rays.

PURPOSE: To evaluate radiation dose and image quality of cervical spinal computed tomography scanned with low-radiation dose (LD-CT) utilizing model-based iterative reconstruction (MBIR). METHODS: We retrospectively examined 14 patients (65.5 ± 13.9 years) who underwent both standard-radiation-dose CT (SD-CT) reconstructed with hybrid iterative reconstruction and LD-CT of cervical spine. The radiation dose, objective image quality indicator, which includes signal-to-noise and contrast-to-noise, and subjective image quality score of the anatomical landmarks in the SD-CT and LD-CT were statistically compared. In addition, the measurement errors of the length of C3 vertebrae (height, anteroposterior length, inner and outer pedicle diameters) between SD-CT and LD-CT were analyzed. RESULTS: Radiation dose of LD-CT was reduced to one-sixth of the dose of SD-CT. The objective image quality indicator of LD-CT was significantly better than that of SD-CT. The subjective image quality of LD-CT was relatively worse than that of SD-CT but generally graded as clinically accepted or higher. There was no remarkable difference between SD-CT and LD-CT in the measurement value of height and anteroposterior length. Inner pedicle diameter was significantly (0.21 ± 0.13 mm) smaller, and outer pedicle diameter was (0.24 ± 0.14 mm) larger on LD-CT than on SD-CT. CONCLUSION: Cervical spinal LD-CT that utilized MBIR enabled radical decrease in radiation dose and provided sufficient image quality for clinical use. This scanning protocol can be a good alternative for protecting patients from exposure to unnecessary radiation, especially when a patient requires multiple CT scans.

Radiation Exposure of Interventional Radiologists during Computed Tomography Fluoroscopy-Guided Percutaneous Cryoablation.

Purpose: The principal aim of this study was to evaluate radiation exposure of interventionalists during computed tomography (CT) fluoroscopy-guided percutaneous cryoablation (PCA) using radiophotoluminescent glass dosimeters (RPLDs). The radioprotective effects of safety glasses and lead apron were also evaluated. Materials and Methods: Radiation exposure of interventionalists during 46 CT fluoroscopy-guided PCA procedures was evaluated. Entrance surface dose (ESD) was measured using RPLDs on multiple sites: five sites, representing eye lens exposure; five sites, representing body exposure; and four sites, representing skin exposure. The ESD values on multiple sites were compared between different PCA procedures (renal, liver, and bone). Results: The mean ESD on the X-ray-side hand exhibited the highest value (358.8 µGy). Regarding evaluation sites representing exposure to the eye lens, the highest ESD inside the radiation protective glasses was detected on the X-ray-side cheek (167.1 µGy). Most ESD values among multiple sites (10/14) were linearly correlated with CT fluoroscopy time. Among them, the ESD values measured during renal and liver PCA were relatively higher than those measured during bone PCA, especially on the chest area outside the lead apron, and on the X-ray tube-side elbow and hand during renal and bone PCA. Radioprotective effects of safety glasses and lead apron ranged from 44.6 to 50.6% and from 30.2 to 79.6%, respectively, on each evaluation site. Conclusion: The site with the highest radiation exposure on interventionalists during CT fluoroscopy-guided PCA was the X-ray tube-side hand. Radiation exposure of interventionalists was at acceptable levels and consistent with the recommended dose limits.

Utility of Thoracolumbar Low-Dose CT With Model-Based Iterative Reconstruction for Measuring Pedicle Diameter Using a Radiation Dose Less Than a One-Time Lumbar X-Ray.

STUDY DESIGN: Retrospective. OBJECTIVE: To evaluate the image quality of low-radiation-dose computed tomography (LD-CT) of the thoracolumbar spine, using model-based iterative reconstruction (MBIR) for measuring pedicle diameter. SUMMARY OF BACKGROUND DATA: MBIR can drastically reduce radiation dose but its utility in spine surgery planning is unknown. METHODS: We identified patients (mean age, 70.5 ±â€Š13.3 yrs) who incidentally underwent both standard-radiation-dose CT (SD-CT) with hybrid iterative reconstruction and LD-CT with MBIR of the thoracolumbar spine within 2 years. We compared radiation dose, subjective image sharpness, signal-to-noise ratio, and contrast-to-noise ratio for the two tests. Additionally, inner pedicle diameters were measured on SD-CT (DSD) and LD-CT (DLD), and statistically compared. RESULTS: We included 24 CT and 84 pedicles for each CT group. The radiation dose of LD-CT estimated by volume CT dose index was 1.21 ±â€Š0.42 mGy, one-sixth the dose of SD-CT. The effective dose of LD-CT was 0.58 ±â€Š0.31 mSv, equivalent to or less than that of a one-time lumbar X-ray in a previous report. LD-CT was significantly inferior in subjective image sharpness for the contour of vertebrae and trabecular structure, but superior for signal-to-noise ratio and contrast-to-noise ratio. The intra-rater reliability (intra-RR) and inter-RR for DLD were 0.985 and 0.892, respectively, comparable to those of DSD. DLD was consistently 0.30 mm smaller than DSD when compared within the same pedicle, regardless of pedicle diameter. CONCLUSION: LD-CT with MBIR produced a radiation dose equivalent to a one-time lumbar X-ray and provided excellent images for measuring pedicle diameter. LD-CT can be a substitute for SD-CT when planning spine surgery if the relationship between DSD and DLD is sufficiently understood. LEVEL OF EVIDENCE: 3.

[Incident Analysis in Radiography Focusing on the Experience Period of Radiological Technologist].

We investigated the causes and trends of incidents related to radiography. From April 2014 to March 2016, 384 incident reports related to radiography were posted. We analyzed based on the nature of the incidents and the experience period of radiological technologist (RT). The types of incidents were 'Incorrect examination order by medical doctor' (50.0%), 'X-ray retake' (24%), 'Incorrect examination procedure' (9.9%), 'Fall or injury of the patient under examination' (3.6%), 'selection error of X-ray detector' (3.1%), 'patient mismatch' (1.8%), 'overdose' (1.3%), and 'others' (a malfunctioning device, trouble of systems and the other) (6.5%). There was no relationship between the number of incidents per person and the experience period as RT; (7.8/person for <3 years of experience, 9.7/person for 3-10 years, 6.4/person for 11-25 years of experience, 7.4/person for <25 years of experience). The experience period as RT are related to some types of incident reduction. 'Fall or injury of the patient under examination' and 'overdose' were more frequently reported by RTs of shorter experience (<3 years and 3-10 years of experience) than RTs of longer experience (11-25 years and <25 of experience). On the other hand, 'patient mismatch' and 'selection error of X-ray detector' were more frequently reported by RTs of long experience than RTs of short experience.

Clarifying Demographic Impacts on Embodied and Materially Retained Carbon toward Climate Change Mitigation.

Modern lifestyles demand a number of products derived from petroleum-based sources that eventually cause carbon emissions. The quantification of lifestyle and household consumption impacts upon carbon emissions from both the embodied CO2 (EC) and materially retained carbon (MRC) viewpoints is critical to deriving amelioration policies and meeting emission reduction goals. This study, for the first time, details a methodology to estimate both EC and MRC for Japan, focusing on petrochemicals and woody products utilizing the time series input-output table, physical value tables and the national survey of family income and expenditure, leveraging time series input-output-based material flow analysis (IO-MFA), and structural decomposition analysis (SDA). Findings elucidated hot spots of deleterious consumption by age of householder and the critical factors which underpin them including intensity effects, pattern effects, and demographic shifts over time. Although demographic shifts associated with an aging, shrinking population in Japan decreased EC and MRC, the negative effect reduced in size over time during 1990-2005. Policy implications identify the potential to mitigate approximately 21% of required household emission reductions by 2030 through strategies including recycling initiatives and the recovery of carbon from products covered within current recycling laws and hot spot sectors which are not currently considered such as apparel.