Development of a New Radiation Shield for the Face and Neck of IVR Physicians.

Interventional radiology (IVR) procedures are associated with increased radiation exposure and injury risk. Furthermore, radiation eye injury (i.e., cataract) in IVR staff have also been reported. It is crucial to protect the eyes of IVR physicians from X-ray radiation exposure. Many IVR physicians use protective Pb eyeglasses to reduce occupational eye exposure. However, the shielding effects of Pb eyeglasses are inadequate. We developed a novel shield for the face (including eyes) of IVR physicians. The novel shield consists of a neck and face guard (0.25 mm Pb-equivalent rubber sheet, nonlead protective sheet). The face shield is positioned on the left side of the IVR physician. We assessed the shielding effects of the novel shield using a phantom in the IVR X-ray system; a radiophotoluminescence dosimeter was used to measure the radiation exposure. In this phantom study, the effectiveness of the novel device for protecting against radiation was greater than 80% in almost all measurement situations, including in terms of eye lens exposure. A large amount of scattered radiation reaches the left side of IVR physicians. The novel radiation shield effectively protects the left side of the physician from this scattered radiation. Thus, the device can be used to protect the face and eyes of IVR physicians from occupational radiation exposure. The novel device will be useful for protecting the face (including eyes) of IVR physicians from radiation, and thus could reduce the rate of radiation injury. Based on the positive results of this phantom study, we plan to perform a clinical experiment to further test the utility of this novel radiation shield for IVR physicians.

Impact of triglyceride levels on plaque characteristics in patients with coronary artery disease.

BACKGROUND: High triglyceride (TG) levels have been demonstrated to be a risk factor for coronary artery disease. This study aimed to clarify the impact of TG levels on the characteristics of coronary plaques. METHODS: A total of 850 consecutive patients who underwent optical coherence tomography (OCT) imaging of the culprit lesion were included. The morphologies of culprit plaques were compared between the higher TG group (nonfasting TG levels ≥150 mg/dL, n = 337) and the lower TG group (nonfasting TG <150 mg/dL, n = 513). RESULTS: The prevalence of lipid-rich plaques (43% vs. 33%, p = 0.005), thin-cap fibroatheromas (TCFAs) (24% vs. 17%, p = 0.015) and macrophages (40% vs. 31%, p = 0.006) was significantly higher in the higher TG group than in the lower TG group. In addition to a high low-density lipoprotein cholesterol (LDL-C) level (≥140 mg/dL), high TGs (≥150 mg/dL) were identified as an independent factor for the presence of TCFAs (odds ratio 1.465, 95% confidence interval 1.004-2.137, p = 0.048). Among patients with lower LDL-C levels (<100 mg/dL), the prevalence of macrophages (38% vs. 26%, p = 0.007) and layered plaques (48% vs. 38%, p = 0.019) was significantly higher in the higher TG group than in the lower TG group. CONCLUSIONS: Higher TG levels were associated with a higher prevalence of TCFAs in culprit coronary lesions. The prevalence of macrophages and layered plaques was more frequently observed in patients with higher TGs than those with lower TGs among patients with LDL-C < 100 mg/dL.

Lower levels of low-density lipoprotein cholesterol are associated with a lower prevalence of thin-cap fibroatheroma in statin-treated patients with coronary artery disease.

BACKGROUND: Reducing low-density lipoprotein cholesterol (LDL-C) levels with statins slows the progression of atherosclerotic plaques and reduces cardiovascular events. The 2019 European Society of Cardiology/European Atherosclerosis Society guidelines recommend absolute LDL-C treatment targets of <100 mg/dL, <70 mg/dL and <55 mg/dL according to coexisting patient risk factors. OBJECTIVE: To clarify the difference in the plaque characteristics of coronary lesions associated with these LDL-C levels in statin-treated patients. METHODS: A total of 685 consecutive statin-treated patients with coronary artery disease (CAD) who underwent optical coherence tomography (OCT) imaging of culprit lesions were enrolled. The characteristics of culprit plaques evaluated by OCT were compared among the high LDL-C group (≥100 mg/dL, n=247), the moderate LDL-C group (70-100 mg/dL, n=289), the low LDL-C group (55-70 mg/dL, n=106) and the very low LDL-C group (<55 mg/dL, n=43). RESULTS: A significant trend toward a lower prevalence of thin-cap fibroatheroma (TCFA) associated with the LDL-C groups was observed (23.1, 18.3, 9.4 and 11.6%, respectively, in each group; p=0.002). A trend toward a lower prevalence of TCFAs associated with the LDL-C groups was also observed among patients with lower hemoglobin A1c (<6.2%; p=0.003). LDL-C <70 mg/dL (the low/very low group) was independently associated with the lack of TCFAs (odds ratio, 0.50; 95% confidence interval, 0.27-0.87, p=0.014). CONCLUSIONS: Lower LDL-C levels were associated with a lower prevalence of TCFAs in culprit plaques among statin-treated patients with CAD.

Characteristics of carotid atherosclerosis in patients with plaque erosion.

Plaque erosion (PE) is a major underlying mechanism of acute coronary syndrome (ACS). Patients with PE may have less systemic atherosclerosis. We aimed to clarify the status of carotid atherosclerosis in patients with PE. A total of 115 consecutive patients with ACS who underwent optical coherence tomography (OCT) imaging of the culprit lesion were enrolled. Patients were classified into PE (n = 26), plaque rupture (n = 56) or calcified plaque (CP, n = 33) based on OCT findings of the culprit lesions. The status of carotid atherosclerosis was assessed by the findings of carotid echography. The mean IMT was the lowest in the PE group (1.5 ± 0.6 mm) among the three groups (p = 0.004) with a significant difference between the PE group and the CP group (2.1 ± 0.6 mm, p < 0.001). The plaque score was the lowest in the PE group (6.6 ± 2.5) among the three groups (p = 0.004) with a significant difference between the PE group and the CP group (9.0 ± 2.7, p < 0.001). Multivariate analyses demonstrated that the PE was independently associated with the presence of lower mean IMT (below median; 1.85 mm) (odds ratio 3.34; 95 % confidence interval 1.07-10.4; p = 0.035) and the lack of heterogenous plaque (odds ratio 2.92; 95 % confidence interval 1.02-8.32; p = 0.037). Patients with PE were associated with less atherosclerosis in the carotid artery than other patients with ACS. These findings may help further clarify the distinct pathophysiology of PE. Carotid atherosclerosis and plaque erosion.

Achilles tendon thickening is associated with higher incidence of adverse cardiovascular event in patients with coronary artery disease.

Achilles tendon thickening (ATT) is a marker of high risk for coronary artery disease (CAD). However, the association between the presence of ATT and the incidence of cardiovascular events in patients with CAD is unclear. A total of 406 consecutive patients who underwent percutaneous coronary intervention (PCI) and ATT assessment were analyzed. ATT was defined as the Achilles tendon thickness of 9 mm or more on radiography. The incidence of major adverse cardiovascular events (MACE) at 1-year was compared between patients with ATT and those without ATT. MACE included cardiac death, non-fatal myocardial infarction, stroke, target vessel revascularization (TVR), and non-TVR. ATT was found in 67 patients (16.5%). The incidence of cardiac death (3.2 vs. 0.0%, p = 0.001), TVR (12.7 vs. 4.0%, p = 0.005) and MACE (20.6 vs. 9.6%, p = 0.011) was significantly higher in the ATT group than the no ATT group. Patients with ATT had significantly higher incidence of cardiac death (5.6 vs. 0%, p < 0.001) than those without ATT even if they did not meet the diagnostic criteria of familial hypercholesterolemia. A multivariate model demonstrated that ATT was independently associated with the MACE at 1-year (Hazard ratio, 2.09; 95% Confidence Interval, 1.09-4.00, p = 0.026). The presence of ATT was independently associated with 1-year recurrence of cardiovascular events in patients with CAD undergoing PCI. Assessment of ATT might be useful for risk stratification of secondary cardiovascular events.

Pancreatic perfusion imaging method that reduces radiation dose and maintains image quality by combining volumetric perfusion CT with multiphasic contrast enhanced-CT.

OBJECTIVES: The aim of this study is to propose and evaluate a new method of volumetric perfusion computed tomography (PCT) incorporated into pancreatic multiphasic contrast enhanced (CE)-CT in the clinical setting. METHODS: In this ethically approved study, PCT was incorporated into our existing scanning protocol in 17 patients and effective doses related to PCT were evaluated. CT values and signal-to-noise ratio (SNR) of anatomical structure were compared in diagnostic images that were acquired using 320-detector volumetric scan mode and 64-detector helical scan mode. In addition, focal lesion depiction was qualitatively assessed in the two groups. Perfusion parameters in normal pancreas were measured by two radiologists and the interobserver-reliability was assessed. RESULTS: The effective dose of PCT was 5.1 ± 0.3 mSv. The actual effective dose (AED) including the dose used in volumetric scans for diagnostic imaging was 22.8 ± 5.3 mSv and the putative effective dose (PED) was 21.9 ± 9.1 mSv on average. There was no significant difference between AED and PED (p = 0.404). Compared with conventional helical scans, volumetric scans did not decrease CT values or SNR, but rather significantly increased those of the aorta in the arterial phase. Both groups had acceptable qualitatively assessed image quality with no significant difference in the depiction of each structure. There was almost perfect interobserver agreement in the measurement of perfusion parameters (mean ICCs > 0.9). CONCLUSIONS: Our scanning protocol for pancreatic perfusion CT provides high-quality images while requiring lower radiation doses than conventional methods.

Endothelial glycocalyx and severity and vulnerability of coronary plaque in patients with coronary artery disease.

BACKGROUND AND AIMS: Endothelial glycocalyx covers the endothelium and maintains vascular integrity. However, its association with the severity and vulnerability of coronary artery disease (CAD) remains to be elucidated. METHODS: A total of 259 consecutive patients with stable CAD requiring percutaneous coronary intervention (PCI) were prospectively enrolled. Patients were classified into 2 groups according to the median value of serum syndecan-1, which is a core component of the endothelial glycocalyx (lower syndecan-1 group [syndecan-1 <99.0 ng/mL], n = 130; higher syndecan-1 group [syndecan-1 ≥99.0 ng/mL], n = 129). Severity of CAD and focal plaque vulnerability in culprit lesion were evaluated using angiography and optical coherence tomography. RESULTS: There was no significant difference in clinical characteristics between the lower syndecan-1 group and the higher syndecan-1 group other than the prevalence of family history of CAD (19 vs. 32%, p = 0.022), prior PCI history (45 vs. 60%, p = 0.015) and estimated glomerular filtration rate (57.8 ± 17.2 vs. 50.9 ± 25.6 ml/min/1.73 m2, p = 0.011). Although disease severity on angiogram was comparable between the 2 groups, the prevalence of lipid-rich plaque (40 vs. 19%, p = 0.004) and thin-cap fibroatheroma (20 vs. 6%, p = 0.006) was significantly higher in the lower syndecan-1 group than the higher syndecan-1 group. Lower syndecan-1 level was independently associated with higher prevalence of lipid-rich plaque (odds ratio 3.626, 95% confidence interval 1.535-8.566, p = 0.003). CONCLUSIONS: Lower syndecan-1 level was associated with higher prevalence of vulnerable plaque in patients with CAD. This finding suggests the association between impaired endothelial glycocalyx and the development of vulnerable plaque.

Physical exertion as a trigger of acute coronary syndrome caused by plaque erosion.

Distinct clinical characteristics have been demonstrated in patients with plaque erosion as compared with those with plaque rupture. We reasoned that greater physical activity might influence the onset of plaque erosion. In total, 97 consecutive patients with non ST-segment elevation acute coronary syndrome (ACS) who underwent optical coherence tomography (OCT) imaging of the culprit lesion were enrolled. OCT-determined culprit plaque characteristics were plaque erosion (18.6%), calcified plaque (26.8%), plaque rupture (32.0%) and other (22.7%). The physical activity evaluated by estimated metabolic equivalents (METs) at ACS onset was significantly greater in the plaque erosion group than in the plaque rupture group (3.3 ± 1.7 vs. 2.1 ± 1.0, p = 0.011). The rate of ACS onset outdoors was the highest (61.1%) in the plaque erosion group. The combination of greater physical activity (> 3 METs), outdoor onset and higher body mass index (> 25.1 kg/m2) had a significant odds ratio for the incidence of plaque erosion (odds ratio 15.0, 95% confidence interval 3.81 to 59.0, p < 0.001). Plaque erosion was associated with greater physical activity at the onset. This finding may help to further clarify the pathogenesis of ACS Impact of physical exertion on the incidence of plaque erosion. NSTE-ACS, non ST-segment elevation acute coronary syndrome.

Novel volumetric analysis for stent expansion after drug-eluting stent implantation: An optical coherence tomography study.

OBJECTIVES: To assess the clinical significance of a novel optical coherence tomography (OCT)-derived volumetric parameter of stent expansion by comparing it with the conventional parameters in real-world practice. BACKGROUND: The clinical significance of novel parameters in real-world practice including longer and smaller stents remains to be elucidated. METHODS: A total of 226 de novo lesion treated with drug-eluting stents in 208 consecutive patients were enrolled. Stent expansion was retrospectively assessed on the final OCT images after stent implantation. The novel parameter was the minimum expansion index (MEI) calculated using a novel algorithm that yields the ideal lumen area in each frame by taking into account vessel tapering. The device-oriented clinical end point (DoCE) included cardiac death, target vessel-related myocardial infarction, ischemia-driven target lesion revascularization. RESULTS: The MEI in the lesions with a DoCE (n = 22) at 2 years and cases without a DoCE (n = 204) was 64.3 ± 12.0% and 78.5 ± 14.6%, respectively (p < .001). In the receiver operating characteristic curve analyses, the areas under the curve for the MEI (0.787; p < .001) were larger than that for %stent expansion (0.718; p = .001) and minimum stent area (0.664; p = .004) in predicting the DoCE. The best cutoff of MEI for predicting the DoCE was 74.0. CONCLUSIONS: The novel MEI was better than the conventional %stent expansion and minimum stent area for predicting DoCE.

Age- and Gender-Related Differences in Coronary Lesion Plaque Composition on Optical Coherence Tomography.

BACKGROUND: The pathophysiology and chronological course of atherosclerosis seems to be different between men and women due to biological differences, and age and gender differences in plaque composition of coronary lesions remain to be elucidated.Methods and Results:A total of 860 consecutive patients with a median age of 69 years (IQR, 60-78 years) who underwent optical coherence tomography (OCT) of culprit lesions was included. The composition of culprit plaque on OCT was compared between female (n=171) and male (n=689) subjects in younger (<70 years old) and elderly (≥70 years old) patients. In elderly patients, the prevalence of thin-cap fibroatheroma (TCFA) was significantly higher in women than in men (30.6 vs. 15.2%, P<0.001). In younger patients, the prevalence of large calcification was significantly higher in women than in men (60.0 vs. 32.8%, P<0.001). The prevalence of other vulnerable plaque characteristics (i.e., macrophages, microchannels, and spotty calcification), was similar between women and men. Elderly women had a significantly higher prevalence of TCFA (OR, 2.13; 95% CI: 1.33-3.44, P=0.002) than other patients. CONCLUSIONS: Women had a higher prevalence of TCFA and of large calcification than men in patients ≥70 and <70 years old, respectively. This may facilitate the understanding of gender differences in the pathogenesis of coronary atherosclerosis, and the tailoring of therapy and of prevention according to age and gender.

[Radiation Exposure in Computed Tomography Localizer Radiograph].

This research measured the radiation exposure of the computed tomography(CT) localizer radiograph of the trunk of the body. The entrance surface dose for CT localizer radiograph was measured using radiophotoluminescent glass dosimeter(RPLD) on four points of measurement, including the center of the phantom, on the surface of a phantom placed in the center of a CT bed, assuming that the subject has a thickness of 20 cm. The entrance surface dose of the localizer radiograph under the chest CT protocol manufacturer's initial setting conditions of 120 kV 35 mA was 0.80 mGy at the center and 0.53 for the 4-location average for the upper X-ray tube (excluding the CT bed), and 0.74 mGy at the center and 0.48 mGy for the 4-location average for the lower X-ray tube (including the CT bed). Compared to the Japan DRLs 2015 chest X-ray (P→A), the entrance surface dose was 2.67 times at the center and 1.77 times for the 4-location average for the upper X-ray tube and 2.47 times at the center and 1.60 times for the 4-location average for the lower X-ray tube. The CT radiation dose also cannot be ignored for the localizer radiograph entrance surface dose.

Contrast Volume and Decline in Kidney Function in Optical Coherence Tomography-Guided Percutaneous Coronary Intervention.

Optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) may increase contrast volume. However, the impact of OCT-guided PCI on the decline in kidney function (DKF) in actual clinical practice remains unclear.Among 1,003 consecutive patients who underwent either OCT-guided or intravascular ultrasound (IVUS)-guided PCI in our institute, we identified 202 propensity score-matched pairs adjusted by baseline factors. The incidence of DKF was compared between the OCT-guided PCI group and the IVUS-guided PCI group. DKF was defined as an increase in serum creatinine level of ≥ 0.5 mg/dL or a relative increase of ≥ 25% over baseline within 48 hours (acute DKF) or 1 month (sustained DKF) after PCI.Baseline characteristics, including the prevalence of chronic kidney disease (54% versus 46%, P = 0.09), were comparable between the OCT- and IVUS-guided PCI groups except for the age. The contrast volume was comparable between the two groups (153 ± 56 versus 144 ± 60 mL, P = 0.09), although it was significantly greater in the OCT-guided PCI group in patients with acute coronary syndrome (ACS; 175 ± 55 versus 159 ± 43 mL, P = 0.04). The incidence of acute DKF (0.5% versus 2.5%, P = 0.22) and sustained DKF (5.0% versus 10.4%, P = 0.31) was comparable between the two groups. Multivariate analysis demonstrated that ACS (odds ratio 4.74, 95% confidence interval 2.72-8.25, P < 0.001) was a predictor of sustained DKF.Compared with IVUS-guided PCI, OCT-guided PCI did not increase the incidence of DKF in actual clinical practice, although the increased contrast volume was observed in ACS cases.

Lipoprotein (a) level is associated with plaque vulnerability in patients with coronary artery disease: An optical coherence tomography study.

BACKGROUND: High lipoprotein (a) [Lp(a)] levels are an independent factor for worse prognosis in patients with coronary artery disease (CAD). However, the association between serum Lp(a) level and coronary plaque vulnerability remains to be determined. METHODS: A total of 255 consecutive patients with CAD who underwent optical coherence tomography imaging of culprit lesions were included. Patients were divided into 2 groups according to their Lp(a) levels (the higher Lp(a) group [≥25 mg/dL], n = 87; or the lower Lp(a) group [<25 mg/dL], n = 168). RESULTS: The prevalence of thin-cap fibroatheroma (TCFA) was significantly higher in the higher Lp(a) group than in the lower Lp(a) group (23% [n = 20] vs. 11% [n = 19], p = 0.014). Although the prevalence of TCFA was comparable between the 2 groups among patients with a lower LDL cholesterol (LDL-C) level (<100 mg/dL), TCFA was significantly more prevalent in the higher Lp(a) group than in the lower Lp(a) group (39% [14/36] vs. 10% [5/50], p = 0.001) among patients with a higher LDL-C level (≥100 mg/dL). CONCLUSIONS: A higher Lp(a) level was associated with a higher frequency of TCFA, particularly in patients with a higher LDL-C level.

Impaired Flow-Mediated Dilation and Severity and Vulnerability of Culprit Plaque in Patients with Coronary Artery Disease.

The association between endothelial function, evaluated using flow-mediated dilatation (FMD), and the severity of coronary artery disease remains to be elucidated.A total of 245 consecutive patients with stable angina were prospectively enrolled. FMD was evaluated in the brachial artery before percutaneous coronary intervention. Patients were divided into 2 groups according to the FMD value (lower FMD group [FMD < 2.0], n = 82; higher FMD group [FMD ≥ 2.0], n = 163). The severity of coronary artery disease was evaluated using findings of angiography and optical coherence tomography, and compared between the 2 groups.The prevalence of left main (LM) disease was significantly higher in the lower FMD group than in the higher FMD group (8.5% versus 2.5%, P = 0.046), although the prevalence of multivessel disease was comparable between the groups. Lower FMD was independently associated with a higher prevalence of LM disease (odds ratio, 3.89; 95% confidence interval, 1.12-15.5; P = 0.033). A general linear model with multiple variables revealed that the minimal lumen area (MLA) in the culprit lesion was significantly smaller in patients with lower FMD than in those with higher FMD (regression coefficient b, -0.249 mm2; 95% confidence interval, -0.479--0.018 mm2; P = 0.035). The prevalence ofvulnerable plaque characteristics was comparable between the 2 groups.Patients with lower FMD had a higher incidence of LM disease and a smaller MLA in the culprit lesion. FMD may be a useful, noninvasive indicator for identifying patients with severe coronary artery disease.

Incidence, factors, and clinical significance of cholesterol crystals in coronary plaque: An optical coherence tomography study.

BACKGROUND AND AIMS: Intraplaque cholesterol crystal (CC) is recognized as a component of vulnerable plaques. However, the clinical characteristics of patients with CC and the impact of CC on clinical events remain unknown. METHODS: A total of 340 consecutive patients who underwent optical coherence tomography (OCT) imaging of culprit lesions were included in the study. CC was defined as a thin linear structure with high reflectivity and low signal attenuation on OCT images. The incidence of major adverse cardiovascular events (MACE) at 1-year was compared between patients with CC (CC group) and those without CC (non-CC group). MACE included cardiac death, non-fatal myocardial infarction, target vessel revascularization (TVR), and non-TVR (NTVR). RESULTS: CC was observed in 29% (n = 98) of the patients. There was no significant difference in baseline clinical characteristics between the CC and non-CC groups, other than in eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio (0.39 ±â€¯0.29 vs. 0.47 ±â€¯0.33, p = 0.047) and hemoglobin A1c (HbA1c) levels (6.51 ±â€¯0.97 vs. 6.25 ±â€¯0.87%, p = 0.016). The incidence of MACE and NTVR at 1-year was significantly higher in the CC group than in the non-CC group (15.3 vs. 7.9%, P = 0.038; 8.1 vs. 2.5%, p = 0.017). The presence of CC was significantly associated with a higher rate of 1-year MACE (odds ratio 4.78, confidential interval 2.02-10.10, p < 0.001). CONCLUSIONS: Patients with CC in the culprit lesion had higher HbA1c and lower EPA/AA than patients without CC. The 1-year clinical outcomes in patients with CC in the culprit lesion were worse than in those without CC.

Lower Level of Low Density Lipoprotein Cholesterol is Associated with a Higher Increase in the Fractional Flow Reserve in Patients with Fixed-dose Rosuvastatin.

AIM: Fractional flow reserve (FFR) reflects on the diffuse atherosclerosis per coronary artery. It is unknown whether the statin therapy affects long term FFR after stenting. The aim of this study was to evaluate the long term FFR after stent implantation in patients who are intaking fixed-dose rosuvastatin. METHODS: A total of 22 patients with stable angina pectoris were enrolled. The values of FFR were measured before, immediately after, and 18 months after (follow-up day) the implantation of everolimus eluting stent (EES; Promus ElementTM or Promus Element PlusTM). A fixed dose of rosuvastatin at 5 mg/day was administrated to all patients. RESULTS: Of the 22 patients, 2 were excluded because of adverse effect of rosuvastatin and in-stent total occlusion after EES implantation. Overall, the values of FFR immediately after and 18 months after EES implantation did not show significant change (from 0.90±0.05 to 0.88±0.06, p=0.16). However, there was a significant negative correlation between low density lipoprotein (LDL) cholesterol level at follow-up day and changes in the value of FFR (p=0.01, r =－0.74). There was an increase in the FFR value after stenting in 8 out of 9 patients with LDL cholesterol level below 75 mg/dl (area under the curve 0.92, p=0.0005). CONCLUSIONS: LDL cholesterol level was associated with the change in the FFR value in patients following stent implantation. Lower LDL cholesterol tended to improve in the long-term FFR, underscoring the importance of lowering LDL cholesterol to prevent the progression of coronary atherosclerosis.

Multicenter Investigation of the Effective Dose for Whole-body CT Scanning.

OBJECTIVE: To study whether the actual radiation exposure is different between computed tomography (CT) scanners and medical centers when the same patient is scanned, we investigated the actual effective doses for a whole body (Chest-Pelvis) CT scan in a multicenter study. MATERIALS AND METHODS: Data from subjects were collected using 12 CT scanners at six medical centers in Yamagata city. Effective-dose data were acquired by scanning the same phantom (ATOM Dosimetry Phantoms Model702-B) using 120 kV tube voltage. Effective doses were calculated using corrected data from a radiophotoluminescent glass dosimeter (GD-302M). GD-302M had energy- dependent issues, which needed to be corrected. Also, differences in sensitivity based on arrangement within the phantom were insignificant. RESULTS: The mean effective energy was 48.6 keV (range, 42.5-55.4 keV), and the mean effective dose was 16.3 mSv (range, 8.9-26.0 mSv). The mean effective dose with a hybrid type iterative reconstruction was 10.7 mSv (range, 8.9-16.4 mSv), but the mean effective dose without any iterative reconstruction was 20.3 mSv (range, 16.2-26.0 mSv). We found an approximate linear correlation between dose length product (DLP) on operation consoles and the effective dose. CONCLUSION: We suggest that the actual radiation exposure was different at each medical center when the same patient is scanned.

The Clinical Value of Nongated Dual-Source Computed Tomography in Atrial Fibrillation Catheter Ablation.

INTRODUCTION: Using a high-pitch dual-source CT (DSCT), we aimed to quantify the amounts of contrast media, radiation doses, and image qualities in patients undergoing pulmonary vein (PV) isolation. METHODS AND RESULTS: The study enrolled 60 patients who were randomly assigned in a 1: 1: 1 ratio to undergo ECG-gated 64-slice multidetector computed tomography (MDCT; group I, n = 20), ECG-gated 128-DSCT (group II, n = 20), and nongated 128-DSCT (group III, n = 20). The total amount of contrast media was lower in groups II and III compared with group I (I: 54.7 ± 5.6, II: 26.6 ± 2.7, and III: 28.7 ± 6.9 mL, P < 0.001). The CT dose index was lower in groups II and III compared with group I (I: 73.1 ± 5.2, II: 3.5 ± 0.1, and III: 3.7 ± 0.1 mGy, P < 0.001). The dose length product was lower in groups II and III compared with group I (I: 1154.8 ± 82.8, II: 75.4 ± 2.3, and III: 77.2 ± 1.9 mGy × cm, P < 0.001). The total CT effective radiation dose was lower in groups II and III compared with group I (I: 16.2 ± 1.2, II: 1.1 ± 0.1, and III: 1.1 ± 0.1 mSv, P < 0.001). The total CT scan duration was shorter in group III compared with groups I and II (I: 30.8 ± 2.2, II: 23.4 ± 3.6, and III: 16.0 ± 2.4 minutes, P < 0.001). There were no significant differences in quality for integrated electroanatomical mapping (EAM) and parameters associated with PV isolation among the 3 groups. CONCLUSION: Nongated 128-DSCT provides sufficient image quality to allow integrated EAM while exposing the patient to less contrast media, lower radiation doses, and shorter CT scan durations.