Evaluation of renovated double J stents using ureter models with and without stenosis.

PURPOSE: Commercial double J stents (DJS) have a uniform shape regardless of the specific nature of various ureteral diseases. We tested renovated DJS and compared them with conventional DJS using ureter models. METHODS: One straight ureter model included stenosis at the distal ureter near the ureterovesical junction and the other did not. We used conventional DJS and renovated 5- and 6-Fr soft DJS for ureter stones and 6-, 7-, and 8.5-Fr hard DJS for tumors. The DJS comprised holes in the upper, middle, or lower one-third of the shaft (length, 24 cm; 2-cm-diameter coils at both ends). More holes were created along the shaft based on the ureteral disease location. Conventional DJS had holes spaced 1 cm apart along the shaft. Renovated DJS had holes spaced 1 cm apart along the shaft with 0.5-cm intervals on the upper, middle, or lower one-third of the shaft. Urine flow was evaluated. RESULTS: As the DJS diameter increased, the flow rate decreased. The flow rates of DJS with holes in the lower shaft were relatively lower than those of conventional DJS and DJS with holes in the upper and middle shafts. In the ureter model without stenosis, 6-, 7-, and 8.5-Fr renovated stents exhibited significantly higher flow rates than conventional stents. In the ureter model with stenosis, 5-, 6-, 7-, and 8.5-Fr renovated stents did not exhibit significantly higher flow rates than conventional stents. CONCLUSION: Renovated stents and conventional stents did not exhibit significant differences in urine flow with stenosis.

Initial experience of thrombectomy using vascular snare with multiple loops for chronic organized thrombi in patients with thrombosed native hemodialysis fistulas.

BACKGROUND: Thrombi in native hemodialysis access frequently exhibit chronic organized feature because they have formed over a long period. Removal of these is quite difficult owing to relatively large volume, resilient feature, limitations of the introducer sheath size, etc. In this study, we report our experience using a vascular snare for the removal of these thrombi in native arteriovenous fistula (AVF). MATERIALS AND METHODS: The medical records of patients who underwent recanalization for thrombosed AVFs from January 2019 to August 2023 were reviewed. During the study period, a total of 29 native fistulas (19 brachiocephalic, nine radiocephalic, and one radiobasilic) in 25 patients were treated using a vascular snare with multiple loops (19 men and six women). Characteristics of the AVFs, endovascular procedures, technical and clinical results, and complications were evaluated. RESULTS: Anatomic and clinical success rates were 96.6% and 100%, respectively. Total thrombosis was observed in 21 (72.4%) fistulas. Aneurysmal changes were found in 22 (75.9%) fistulas. The mean fistula age at the time of the procedure was 60.9 months (standard deviation, 52.2). Thrombectomy was initiated using a vascular snare in 14 fistulas. In 15 fistulas for which the procedures were initiated using a rotational percutaneous thrombectomy device (PTD), a vascular snare was subsequently used because recanalization failed or was insufficient due to chronic organizing thrombi. Additional aspiration and balloon angioplasty were performed in 27 (93.1%) and 28 (96.6%), respectively. Pharmacological thrombolysis was performed in one fistula for long segmental thrombosis combined with arterial thrombosis. The mean procedure time, excluding thrombolysis, was 91.9 min (standard deviation, 55.5). No complications related to the use of the vascular snare was observed. CONCLUSION: The use of a vascular snare with multiple loops was safe and highly effective for the removal of chronic organized thrombi in the recanalization of thrombosed AVFs.

Optimal thrombin injection method for the treatment of femoral artery pseudoaneurysm.

BACKGROUND: Iatrogenic femoral artery pseudoaneurysm (IFP) incidence is increasing with increase in diagnostic and therapeutic angiography, and so, the less invasive percutaneous thrombin injection (PTI) is the most widely used treatment. Moreover, studies that minimize PTI complications and highlight therapeutic effects are lacking. OBJECTIVES: This study performed in vitro thrombosis modeling of pseudoaneurysms and analyzed thrombosis within and thromboembolism outside the sac during thrombin injection. METHODS: We evaluated PTI in terms of thrombin injection location (at the junction of the IFP sac and neck, the center, and the dome, located farthest from the neck of the sac), thrombin injection time (5 and 8 seconds), and blood flow rate (ranging from 210 mL/min to 300 mL/min). Porcine blood was used as the working fluid in this study. RESULTS: Thrombin injection at the junction of the IFP sac and the pseudoaneurysm neck led to less thrombosis within the sac but substantial thrombi consistently outside the sac, whereas thrombin injected at the sac center mostly led to complete thrombosis within the sac, preventing further blood flow into the sac and reducing likelihood of thrombi outside the sac. A longer thrombin injection time enhanced the therapeutic effect and decreased the possibility of thromboembolism. Thromboembolism occurred more frequently at flow rates of >240 mL/min. CONCLUSION: The thrombin injection site in a pseudoaneurysm significantly influences thrombogenesis within and thromboembolism outside the sac. Thus, slow and deliberate injection of thrombin into the center of the sac could potentially reduce complications and enhance treatment efficacy.

Lung function trajectory of rheumatoid arthritis-associated interstitial lung disease.

OBJECTIVES: To explore the course of lung function and RA disease activity and predictive factors for deteriorating lung function in patients with RA-interstitial lung disease (ILD). METHODS: The Korean Rheumatoid Arthritis-Interstitial Lung Disease cohort is a multicentre, prospective observational cohort. Patients with RA-ILD were enrolled and followed up annually for 3 years for RA disease activity and ILD status assessment. Group-based modelling was used to cluster a similar predicted percentage of forced vital capacity (FVC%) patterns into trajectories. RESULTS: This study included 140 patients who underwent at least two pulmonary function tests. Four distinctive trajectories for predicted FVC% were 'improving' [n = 11 (7.9%)], 'stable' [n = 68 (38.4%)], 'slowly declining' [n = 54 (48.6%)] and 'rapidly declining' [n = 7 (5.0%)]. Most (77.7%) patients maintained or improved to low RA disease activity. The lung function trajectory was not comparable to the RA disease activity trajectory. Age ≥70 years [relative risk (RR) 10.8 (95% CI 1.30, 89.71)] and early RA diagnosed within the preceding 2 years [RR 10.1 (95% CI 1.22, 84.2)] were associated with increased risk for rapidly declining predicted FVC%. The risk for deterioration or mortality increased in patients with a simultaneous diagnosis of RA and ILD within 24 weeks [RR 9.18 (95% CI 2.05, 41.0)] and the extent of lung involvement [RR 3.28 (95% CI 1.12, 9.60)]. CONCLUSION: Most patients with RA-ILD experienced stable or slowly declining lung function. In 5% of patients, predicted FVC% deteriorated rapidly, especially in older adults with early RA. The lung function trajectory was not comparable to the RA disease activity trajectory.

Methotrexate, leflunomide and tacrolimus use and the progression of rheumatoid arthritis-associated interstitial lung disease.

OBJECTIVE: To examine the association between MTX, LEF and tacrolimus use and the progression of RA-associated interstitial lung disease (ILD). METHODS: The Korean RA-ILD cohort prospectively enrolled patients with RA-associated ILD at multiple centres from 2015 to 2018 and followed up with them for 3 years. ILD progression was defined by any of the followings: a decrease of ≥10% in forced vital capacity, a decrease of ≥15% in the diffusing capacity of the lung for carbon monoxide, or death from respiratory failure. RESULTS: Of 143 patients, 64 patients experienced ILD progression during a median follow-up period of 33 months. The use of MTX [adjusted hazard ratio (aHR), 1.06; 95% CI, 0.59, 1.89], LEF (aHR, 1.75; 95% CI, 0.88, 3.46) and tacrolimus (aHR, 0.94; 95% CI, 0.52, 1.72) did not increase the risk of ILD progression. However, the association between LEF use and the risk of ILD progression was significant in subgroups with poor lung function (aHR, 8.42; 95% CI, 2.61, 27.15). Older age, male sex, a shorter RA duration, higher RA disease activity and extensive disease at baseline were independently associated with ILD progression. CONCLUSION: None of the three treatments increased the risk of RA-associated ILD progression, except for LEF, which increased the risk of ILD progression in patients with severe ILD. The appropriate use of conventional synthetic disease-modifying antirheumatic drugs considering RA disease activity and ILD severity would be important for the management of RA-associated ILD.

Percutaneous Thrombin Injection Based on Computational Fluid Dynamics of Femoral Artery Pseudoaneurysms.

OBJECTIVE: To analyze the computational fluid dynamics (CFD) of femoral artery pseudoaneurysm (FAP), identify a suitable location and timing for percutaneous thrombin injection (PTI) based on this analysis, and report our clinical experience with the procedure. MATERIALS AND METHODS: CFD can be used to analyze the hemodynamics of the human body. An analysis using CFD recommended that the suitable location of the needle tip for PTI is at the center of the aneurysm sac and the optimal timing for starting PTI is during the early inflow phase of blood into the sac. Since 2011, seven patients (three male and four female; median age, 60 years [range, 43-75 years]) with FAP were treated with PTI based on the devised suitable location and time. Prior to the procedure, color Doppler ultrasonography was performed to determine the location and timing of the thrombin injection. RESULTS: The technical success rate of the PTI was 100%. The amount of thrombin used for the procedure ranged from 200 IU to 1000 IU (median, 500 IU). None of the patients experienced any symptoms or signs of embolic complications during the procedure. Follow-up CT images did not reveal any embolism in the lower extremities and showed complete thrombosis of the pseudoaneurysm. CONCLUSION: Based on our study of CFD, PTI administered centrally in the FAP during early inflow, as seen on color Doppler, can be an effective technique.

Variations of bronchial artery origin in 600 patients: Systematic analysis with multidetector computed tomography and digital subtraction angiography.

ABSTRACT: To identify and evaluate the spectrum and prevalence of variations in bronchial artery (BA) origin by multidetector computed tomography (MDCT) and digital subtraction angiography (DSA) in a large population with hemoptysis.From July 2008 to June 2015, data from 600 individuals with hemoptysis who underwent MDCT and DSA were retrospectively analyzed. The pattern of BA origin was investigated and classified according to distribution.A total of 1674 BAs were evaluated, 866 were right BA and 808 were left BA. Most BAs originated from the upper descending thoracic aorta, classified as orthotopic origin (n = 1464, 87.5%). Among ectopic origin BAs (n = 210, 12.5%), concavity of the aortic arch was the most common (n = 107). The most common distribution pattern was a single artery in each side (n = 262). According to our classification, Type I was most common (n = 457), including BAs originating in orthotopic fashion from the descending thoracic aorta. Type II (n = 2) was defined as BAs originating from the aortic arch or ascending aorta. Type III (not found) was defined as BAs originating from subclavian arteries, common carotid arteries, and their branch vessels. Type IV (n = 92) was Type I and II combined, Type V (n = 41) was Type I and III combined, Type VI (not found) was Type II and III combined, and Type VII (n = 8) was Type I, II, and III combined.Variations of BA origin could be systematically described in detail.

Predictive factors affecting percutaneous drainage duration in the percutaneous treatment of common bile duct stones.

The duration of percutaneous transhepatic biliary drainage (PTBD) is a critical factor that determines the duration of treatment. This study aimed to evaluate factors affecting the PTBD duration in patients who underwent percutaneous treatment of common bile duct (CBD) stones. This study analyzed data of 169 patients who underwent percutaneous treatment of CBD stones from June 2009 to June 2019. Demographic data, characteristics of stone, procedure-related factors, and laboratory findings before the insertion of PTBD tubes were retrospectively evaluated. To assess the effect of confounding factors on the PTBD duration, multivariate linear regression analysis was applied, incorporating significant predictive factors identified in the univariate regression analysis. In the univariate regression analysis, the predictive factor that showed high correlation with the PTBD duration was the initial total bilirubin level (coefficient = 0.68, P < .001) followed by the short diameter of the largest stone (coefficient = 0.19, P = .056), and previous endoscopic sphincterotomy (coefficient = -2.50, P = .086). The multivariate linear regression analysis showed that the initial total bilirubin level (coefficient = 0.50, P < .001) and short diameter of the largest stone (coefficient = 0.16, P = .025) were significantly related to the PTBD duration. The total bilirubin level before PTBD tube insertion and the short diameter of the largest CBD stone were predictive factors for the PTBD duration in patients who underwent percutaneous CBD stone removal. Careful assessment of these factors might help in predicting the treatment period, thereby improving the quality of patient care.

Prevalence and predictors of peripherally inserted central venous catheter associated bloodstream infections in cancer patients: A multicentre cohort study.

Despite increasing use, the exact prevalence and predictors of peripherally inserted central catheter-associated bloodstream infection (PICC-CLABSI) in hospitalized patients with cancer are not elucidated.This retrospective cohort study included consecutive patients who underwent peripherally inserted central catheter (PICC) placement in 4 institutions (during 12 months in 3 hospitals and 10 months in 1 hospital). The prevalence of PICC-CLABSI was evaluated. The association between predictors and PICC-CLABSI were analyzed using Cox proportional hazards regression models and Kaplan-Meier survival analysis with log-rank tests.During the study period, 539 PICCs were inserted in 484 patients for a total of 10,841 catheter days. PICC-CLABSI occurred in 25 (5.2%) patients, with an infection rate of 2.31 per 1000 catheter days. PICC for chemotherapy (hazards ratio [HR] 11.421; 95% confidence interval (CI), 2.434-53.594; P = .019), double lumen catheter [HR 5.466; 95% CI, 1.257-23.773; P = .007], and PICC for antibiotic therapy [HR 2.854; 95% CI, 1.082-7.530; P = .019] were associated with PICC-CLABSI.PICC for chemotherapy or antibiotics, and number of catheter lumens are associated with increased risk of PICC-CLABSI in cancer patients. Careful assessment of these factors might help prevent PICC-CLABSI and improve cancer patients care.

[Efficacy and Safety of a Newly Developed Self-Expanding Open-Cell Type Nitinol Stent for Peripheral Arteries: A Preclinical Study in Minipigs]. / 새로 개발된 말초동맥용 자가팽창성 개방형 니티놀 ìŠ¤í íŠ¸ì˜ ìœ íš¨ì„± 및 ì•ˆì „ì„± 평가: 미니피그 ì „ìž„ìƒì‹¤í—˜.

Purpose: To evaluate the safety and efficacy of the newly designed open-cell type self-expandable nitinol stent (NiTi-stent) for peripheral arteries. Materials and Methods: Twenty-eight limbs of 14 minipigs were randomly assigned to the NiTi-stent group or conventional nitinol stent group. Stents were symmetrically implanted into the iliac arteries of each animal using carotid artery approach and were observed for 1 month (n = 5) and 6 months (n = 9). The angiographic lumen diameter (ALD), late lumen loss, angiographic stenosis, histomorphometric lumen area, neointimal area, and area stenosis were analyzed and compared between the groups. Results: Stent migration, stent fracture, or thrombus formation were not observed in either group. At the 1-month follow-up, the neointimal area (p = 0.008) and area stenosis (p = 0.016) were significantly smaller in the NiTi-stent group than in the control group. At the 6-months follow-up, the NiTi-stent group showed significantly larger ALD (p = 0.014), less late lumen loss (p = 0.019), less angiographic stenosis (p = 0.014), larger lumen area (p = 0.040), and smaller neointimal area and area stenosis (p = 0.004 and p = 0.014, respectively) compared with the control group. Conclusion: The NiTi-stent is as safe and effective as the conventional nitinol stent and induces less neointimal hyperplasia in a minipig iliac artery model.

Hemoptysis requiring bronchial artery embolization in patients with nontuberculous mycobacterial lung disease.

BACKGROUND: Although infections caused by nontuberculous mycobacteria (NTM) are increasing in prevalence, there are few data about hemoptysis in patients with NTM lung disease. This study investigated the characteristics and prognosis of hemoptysis secondary to NTM infection. METHODS: Following a retrospective review of cases managed between 2006 and 2016, 183 patients with NTM lung disease were enrolled and analyzed. RESULTS: Among 183 patients with NTM lung disease, Mycobacterium intracellulare (n = 64, 35%) was the major cause of NTM infection, followed by M. avium (n = 59, 32.2%) and M. abscessus complex (n = 40, 21.9%). Hemoptysis developed in 78 patients (42.6%), among whom 33 (42.3%) required bronchial artery embolization (BAE). Between patients with and without hemoptysis, there were no significant differences with respect to sex, radiographic manifestations, distribution over 3 lobes on chest computed tomography, history of pulmonary tuberculosis, antiplatelet or anticoagulation therapy, and species of NTM. However, mean age at diagnosis was significantly lower in the hemoptysis group in univariate and multivariate analyses (65.7 ± 12.8 vs. 59.7 ± 11.8, P = 0.002, odds ratio: 0.969, 95% confidence interval: 0.944-0.996). Among patients with hemoptysis, those requiring medical therapy and those requiring BAE were not significantly different in terms of demographic characteristics, radiographic manifestations, and distribution over 3 lobes. All patients who received BAE showed immediate clinical improvement, no procedure-related complications, and none of them died during the period under review. CONCLUSIONS: NTM lung disease patients commonly experienced hemoptysis without specific risk factors except for relatively young age. Although some patients with hemoptysis needed BAE, the success rate of BAE was high, and there were no serious complications associated with BAE.

The Efficacy of Cone-Beam CT-Based Liver Perfusion Mapping to Predict Initial Response of Hepatocellular Carcinoma to Transarterial Chemoembolization.

PURPOSE: To evaluate efficacy of cone-beam CT-based liver perfusion mapping obtained immediately following conventional transarterial chemoembolization of hepatocellular carcinoma (HCC) for assessing tumor vascularity, technical success of chemoembolization, and treatment response. MATERIALS AND METHODS: From July 2015 to June 2016, 35 patients with 57 HCCs who underwent cone-beam CT with post-processing software via conventional transarterial chemoembolization for HCC and follow-up examination were included. Three reviewers evaluated technical success on angiography, unenhanced cone-beam CT, contrast-enhanced cone-beam CT, and cone-beam CT-based liver perfusion mapping after transarterial chemoembolization per tumor and per patient. Parenchymal blood volume (PBV) was measured. Treatment response was determined on follow-up CT, MR imaging, or histopathology according to modified Response Evaluation Criteria In Solid Tumors. Diagnostic performance for detection of a viable tumor was evaluated using multiple logistic regression with C-statistics. RESULTS: Treatment response was 38, 17, 2, and 0 for complete response, partial response, stable disease, and progressive disease per tumor and 18, 15, 2, and 0 per patient. In multiple logistic regression, unenhanced cone-beam CT, contrast-enhanced cone-beam CT, cone-beam CT-based liver perfusion mapping, mean value of PBV, and maximum value of PBV of tumor were significant in response assessment for per tumor and per patient (per tumor, all P < .001; per patient, P = .015, P = .001, P < .001, P = .020, and P = .032). Mean value of PBV of tumor was excellent for evaluating technical success with the highest C-statistic (0.880 and 0.920 for per tumor and per patient), followed by that of visual assessment of cone-beam CT-based liver perfusion mapping (0.864 and 0.908). CONCLUSIONS: Cone-beam CT-based liver perfusion mapping provided reliable images to evaluate technical success after transarterial chemoembolization of HCC by qualitative visual assessment and quantitative perfusion values.

Sensitivity Analysis of Weather Variables on Offsite Consequence Analysis Tools in South Korea and the United States.

We studied sensitive weather variables for consequence analysis, in the case of chemical leaks on the user side of offsite consequence analysis (OCA) tools. We used OCA tools Korea Offsite Risk Assessment (KORA) and Areal Location of Hazardous Atmospheres (ALOHA) in South Korea and the United States, respectively. The chemicals used for this analysis were 28% ammonia (NH3), 35% hydrogen chloride (HCl), 50% hydrofluoric acid (HF), and 69% nitric acid (HNO3). The accident scenarios were based on leakage accidents in storage tanks. The weather variables were air temperature, wind speed, humidity, and atmospheric stability. Sensitivity analysis was performed using the Statistical Package for the Social Sciences (SPSS) program for dummy regression analysis. Sensitivity analysis showed that impact distance was not sensitive to humidity. Impact distance was most sensitive to atmospheric stability, and was also more sensitive to air temperature than wind speed, according to both the KORA and ALOHA tools. Moreover, the weather variables were more sensitive in rural conditions than in urban conditions, with the ALOHA tool being more influenced by weather variables than the KORA tool. Therefore, if using the ALOHA tool instead of the KORA tool in rural conditions, users should be careful not to cause any differences in impact distance due to input errors of weather variables, with the most sensitive one being atmospheric stability.

Use and limitations of offsite consequence analysis tools from South Korea and the United States in hydrogen fluoride accidental release.

We investigated the characteristics and limitations in the event of hydrofluoric acid (HF) leakage by comparing and analyzing the offsite consequence analysis (OCA) tools based on the chemical plant operating conditions. We reviewed the tools Korea Offsite Risk Assessment (KORA) from South Korea and Risk Management Plan*Comp (RMP*Comp™) and Areal Location of Hazardous Atmospheres (ALOHA) from the United States. The scenario studied was based on a leak event from a 50% HF aqueous solution storage tank, and the operating conditions taken into consideration were the operating temperature and dike installation conditions. The results from the OCA differed; KORA presented a smaller range of offsite impact than did ALOHA. The offsite impact ranges of KORA and ALOHA increased as the operating temperature and dike installation area increased. However, RMP*Comp differed greatly in its offsite impact range results in the operating temperature range of 25 °C to 30 °C. Moreover, in the alternative scenario, a limitation existed in that the offsite impact range was not changed by the dike installation conditions. The offsite impact range analyzed via KORA and ALOHA reflected the reality of an HF leak accident better than that analyzed via RMP*Comp. Therefore, it is more reasonable to use KORA and ALOHA instead of RMP*Comp in OCA. Moreover, users should realize that ALOHA has a somewhat wider range of offsite impact than KORA does in OCA. The separation distance from the storage tank when installing a dike is effective between 1 and 1.5 m in consideration of securing the minimum workspace for workers. Integr Environ Assess Manag 2018;14:205-211. © 2017 SETAC.

Evaluation of a chemical risk assessment method of South Korea for chemicals classified as carcinogenic, mutagenic or reprotoxic (CMR).

OBJECTIVES: Chemicals were used in various fields by the development of industry and science and technology. The Chemical Hazard Risk Management (CHARM) was developed to assess the risk of chemicals in South Korea. In this study, we were to evaluate the CHARM model developed for the effective management of workplace chemicals. MATERIAL AND METHODS: We used 59 carcinogenic, mutagenic or reprotoxic (CMR) materials, which are both the work environment measurement result and the usage information among the manufacturer data. The CHARM model determines the risk to human health using the exposure level (based on working environment measurements or a combination of the quantity used and chemical physical properties (e.g., fugacity and volatility)), hazard (using occupational exposure limit (OEL) or Risk phrases (R-phrases)/Hazard statements (H-statements) from the Material Safety Data Sheet (MSDS)). RESULTS: The risk level was lower when using the results of the work environment measurement than when applying the chemical quantity and physical properties in the exposure level evaluation method. It was evaluated as grade 4 for the CMR material in the hazard class determination. The risk assessment method by R-phrases was evaluated more conservatively than the risk assessment method by OEL. And the risk assessment method by H-statements was evaluated more conservatively than the risk assessment method by R-phrases. CONCLUSIONS: The CHARM model was gradually conservatively assessed as it proceeded in the next step without quantitative information for individual workplaces. The CHARM is expected to help identify the risk if the hazards and exposure levels of chemicals were identified in individual workplaces. For CMR substances, although CHARM is highly evaluated for hazards, the risk is assessed to be low if exposure levels are assessed low. When evaluating the risk of highly hazardous chemicals such as CMR substances, we believe the model should be adapted to be more conservative and classify these as higher risk. Int J Occup Med Environ Health 2018;31(4):491-501.

Effects of anatomical characteristics as factors in abdominal aortic aneurysm rupture: CT aortography analysis.

The aim of this study was to analyze the anatomical characteristics of patients with ruptured abdominal aortic aneurysms (AAAs) using computed tomography (CT) aortography in order to determine the risk factors for rupture.We retrospectively reviewed the CT aortography findings and medical records of patients with ruptured AAAs who underwent CT aortography between February 2002 and December 2014. Age, sex, blood pressure at the time of rupture, treatment methods used for the ruptured AAAs, and treatment outcomes were analyzed. Statistical analyses were performed to determine the association between the maximum aneurysm diameter, which is considered the standard predictor of aneurysm rupture, and anatomical characteristics such as proximal neck diameter, angle between the suprarenal aorta and the aneurysm neck (α angle), angle between the aneurysm neck and aneurysm sac (ß angle), and angles between the abdominal aorta and both iliac arteries.Data were reviewed for a total of 36 patients. The mean maximum diameter of AAAs was 76.84 ±â€Š21.08 mm. Multivariate analysis adjusted for age and sex indicated statistical correlations between the α and ß angles and maximum aneurysm diameter and between the ß angle and iliac artery involvement.Our results suggest that the tortuosity of the aorta tends to be associated with the diameter of AAAs and iliac artery involvement. Investigation of the anatomical characteristics of individual patients using CT aortography is expected to aid in predicting the risk of AAA rupture.

Cone Beam CT-Guided Chemoembolization of Probable Hepatocellular Carcinomas Smaller than 1 cm in Patients at High Risk of Hepatocellular Carcinoma.

PURPOSE: To evaluate the effectiveness and safety of cone-beam computed tomography (CT)-guided chemoembolization for probable hepatocellular carcinomas (HCCs) smaller than 1 cm in patients at high risk for HCC. MATERIALS AND METHODS: From December 2009 to May 2014, 57 patients (43 male and 14 female; mean age, 61.1 y) at high risk for HCC underwent cone-beam CT-guided conventional chemoembolization for 79 treatment-naive probable HCCs < 1 cm. Probable HCCs were diagnosed when hepatic nodules showed arterial enhancement and washout on dynamic CT or magnetic resonance images. The Kaplan-Meier method and Cox proportional-hazards regression were used to evaluate the time to local progression (TTLP), time to progression (TTP), and overall survival (OS). RESULTS: Initial follow-up images obtained 2-3 months after chemoembolization showed complete response in all 79 tumors. The 1-, 2-, and 3-year local progression rates were 10.4%, 21.7%, and 35.7%, respectively. Subsegmental catheterization (P < .001; hazard ratio [HR] = .041) and segmental catheterization (P = .001; HR = .049) were significantly associated with longer TTLP. The 1-, 2-, and 3-year progression rates were 40.5%, 66.7%, and 78.6%, respectively. Tumor multiplicity (P = .004; HR = 2.612) was a significant risk factor for shorter TTP. The 1-, 2-, and 3-year OS rates were 100%, 98.2%, and 88.5%, respectively. Child-Turcotte-Pugh class B disease (P = .029; HR = 5.989) was significantly associated with shorter OS. No complications occurred after chemoembolization. CONCLUSIONS: Cone-beam CT-guided chemoembolization can be a useful and safe option for probable HCCs < 1 cm in patients at high risk for HCC.

Comparison of chemical risk assessment methods in South Korea and the United Kingdom.

OBJECTIVES: The objective of this study was to compare Control of Substances Hazard to Health (COSHH) Essentials (a chemical risk assessment method in the UK) with Chemical Hazard Risk Management (CHARM) (a chemical risk assessment method in South Korea). The differences between the two processes were explored with a particular focus on their features and distinctions. METHODS: The results obtained from applying COSHH Essentials and CHARM to 59 carcinogenic, mutagenic, and reprotoxic (CMR) substances were analyzed. The outcomes of the working environment assessments and the collated information about the usage of CMR chemicals were used for the analysis. RESULTS: Among the 59 substances tested, 56 substances were rated at a risk level lower than 2, when evaluated with CHARM. However, with COSHH, all 59 substances were rated at risk level 3 or higher. With COSHH Essentials, the highest hazard group of 4 was automatically assigned to category E substances, regardless of the exposure level assessment. However, for CHARM, the risk could be adjusted according to the exposure level assessment, even for hazard group of 4. CONCLUSIONS: CHARM allocated lower risk levels to hazardous substances than COSHH Essentials. Ultimately, COSHH Essentials assesses exposure level through the physical properties and overall handling, and considers hazard with H-statements and R-phrases. COSHH Essentials was deemed more conservative than CHARM. CHARM may have underestimated the risk according to exposure level, even though the chemicals were highly hazardous. Therefore, CHARM can be used for the localized risk assessment of chemicals used in individual workplaces.

Evaluation of lymph node metastases: comparison of gadofluorine M-enhanced MRI and diffusion-weighted MRI in a rabbit VX2 rectal cancer model.

PURPOSE: To compare the diagnostic performance of a diffusion-weighted imaging (DWI) dataset and a gadofluorine M-enhanced imaging dataset for identifying lymph node (LN) metastases in a rabbit rectal cancer model. MATERIALS AND METHODS: VX2 carcinomas were injected into the rectum of 26 rabbits. Four weeks later, T2-weighted imaging (T2WI), pre-T1WI, DWI, and post-T1WI were performed. Two radiologists independently reviewed the DWI set (T2WI, pre-T1WI, DWI) and the gadofluorine M set (T2WI, pre- and post-T1WI) and recorded their confidence scores for LN metastasis on a per-LN basis. Receiver operating characteristic (ROC) analysis was performed to compare the area under the ROC curve (A(z) ) of the two imaging sets. Histopathologic results were used as the reference standard. RESULTS: The A(z) and sensitivity of the gadofluorine M set were comparable to those of the DWI set (A(z) , for reader 1, 0.849, 0.829, P = 0.571; for reader 2, 0.923, 0.876, P = 0.212; sensitivity, for reader 1, 97%, 97%; for reader 2, 97%, 92%, P = 0.304). The specificity of the former was greater than that of the latter (for reader 1, 65%, 53%, P = 0.0003; for reader 2, 81%, 68%, P = 0.01). CONCLUSION: Gadofluorine M-enhanced images provided greater specificity than DWI for identifying LN metastases, whereas the A(z) and sensitivity of the former were comparable to those of the latter.

Hepatocellular carcinomas smaller than 4 cm supplied by the intercostal artery: can we predict which intercostal artery supplies the tumor?

OBJECTIVE: To predict which intercostal artery supplies a tumor by examining the spatial relationship between hepatocellular carcinoma (HCC) and the intercostal artery feeding the tumor on transverse computed tomography (CT) images. MATERIALS AND METHODS: Between January 2000 and September 2009, 46 intercostal arteries supplying HCCs smaller than 4 cm were noted in 44 patients, and CT scans and angiograms of these patients were retrospectively reviewed. The intercostal artery feeding the tumor was marked on the CT scan showing the center of the tumor. In addition, its spatial relationship with the tumor center was examined. The angle of the tumor location was measured on the transverse CT scan in the clockwise direction from the sagittal line on the virtual circle centered in the right hemithorax. Correlations between the angle of the tumor location and the level of the tumor-feeding intercostal artery were assessed with the Spearman rank coefficient. RESULTS: Of 46 intercostal arteries feeding HCC, 39 (85%) were the first ones observed from the tumor center in a counterclockwise direction on the transverse CT image containing the tumor center. The level of the tumor-feeding intercostal artery was significantly correlated with the angle of the tumor, as the posteriorly located tumor tends to be supplied by lower intercostal arteries, while the laterally located tumor by upper intercostal arteries (Spearman coefficient = -0.537; p < 0.001). CONCLUSION: We can predict the tumor feeder with an accuracy of 85% as the first intercostal artery encountered from the tumor center in a counterclockwise direction on a transverse CT image.