Demands for medical imaging and workforce Size: A nationwide population-based Study, 2000-2020.

PURPOSE: The aim of this study was to investigate associations between workforce and workload among radiologists in Taiwan. MATERIALS AND METHODS: Data for the period 2000-2020 describing the demand for imaging services and radiologists have been obtained from databases and statistical reports of the Ministry of Health and Welfare. The future demand for radiologists was based on Taiwanese people aged 40 and over. RESULTS: The workforce of Taiwan's radiologists has increased by 6 % annually over the past 20 years (from 450 to 993), performing 2125, 3202 and 3620 monthly examinations (mainly conventional radiography and CT) in medical centers, regional hospitals and district hospitals. Between 2000 and 2020, the use of CT and MRI increased by more than 3.5 times. Demand for interventional radiology also increased by 1.77 times, 2.25 times, and 5 times, respectively. To maintain this volume of services in 2040, at least 1168 radiologists are needed, about 1.18 times more in 2020. CONCLUSION: Taiwan has 2.4 to 2.9 times fewer radiologists than the United States and 3 times fewer than Europe, while the annual workload is approximately 2 to 3.4 times greater than that of the United States and 1.4 to 2.5 times greater than that of the United Kingdom. This report may serve as a reference for policy makers who address the challenges of the growing workload among radiologists in countries of similar situations.

Low-dose CT screening among never-smokers with or without a family history of lung cancer in Taiwan: a prospective cohort study.

BACKGROUND: In Taiwan, lung cancers occur predominantly in never-smokers, of whom nearly 60% have stage IV disease at diagnosis. We aimed to assess the efficacy of low-dose CT (LDCT) screening among never-smokers, who had other risk factors for lung cancer. METHODS: The Taiwan Lung Cancer Screening in Never-Smoker Trial (TALENT) was a nationwide, multicentre, prospective cohort study done at 17 tertiary medical centres in Taiwan. Eligible individuals had negative chest radiography, were aged 55-75 years, had never smoked or had smoked fewer than 10 pack-years and stopped smoking for more than 15 years (self-report), and had one of the following risk factors: a family history of lung cancer; passive smoke exposure; a history of pulmonary tuberculosis or chronic obstructive pulmonary disorders; a cooking index of 110 or higher; or cooking without using ventilation. Eligible participants underwent LDCT at baseline, then annually for 2 years, and then every 2 years up to 6 years thereafter, with follow-up assessments at each LDCT scan (ie, total follow-up of 8 years). A positive scan was defined as a solid or part-solid nodule larger than 6 mm in mean diameter or a pure ground-glass nodule larger than 5 mm in mean diameter. Lung cancer was diagnosed through invasive procedures, such as image-guided aspiration or biopsy or surgery. Here, we report the results of 1-year follow-up after LDCT screening at baseline. The primary outcome was lung cancer detection rate. The p value for detection rates was estimated by the χ2 test. Univariate and multivariable logistic regression analyses were used to assess the association between lung cancer incidence and each risk factor. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of LDCT screening were also assessed. This study is registered with ClinicalTrials.gov, NCT02611570, and is ongoing. FINDINGS: Between Dec 1, 2015, and July 31, 2019, 12 011 participants (8868 females) were enrolled, of whom 6009 had a family history of lung cancer. Among 12 011 LDCT scans done at baseline, 2094 (17·4%) were positive. Lung cancer was diagnosed in 318 (2·6%) of 12 011 participants (257 [2·1%] participants had invasive lung cancer and 61 [0·5%] had adenocarcinomas in situ). 317 of 318 participants had adenocarcinoma and 246 (77·4%) of 318 had stage I disease. The prevalence of invasive lung cancer was higher among participants with a family history of lung cancer (161 [2·7%] of 6009 participants) than in those without (96 [1·6%] of 6002 participants). In participants with a family history of lung cancer, the detection rate of invasive lung cancer increased significantly with age, whereas the detection rate of adenocarcinoma in situ remained stable. In multivariable analysis, female sex, a family history of lung cancer, and age older than 60 years were associated with an increased risk of lung cancer and invasive lung cancer; passive smoke exposure, cumulative exposure to cooking, cooking without ventilation, and a previous history of chronic lung diseases were not associated with lung cancer, even after stratification by family history of lung cancer. In participants with a family history of lung cancer, the higher the number of first-degree relatives affected, the higher the risk of lung cancer; participants whose mother or sibling had lung cancer were also at an increased risk. A positive LDCT scan had 92·1% sensitivity, 84·6% specificity, a PPV of 14·0%, and a NPV of 99·7% for lung cancer diagnosis. INTERPRETATION: TALENT had a high invasive lung cancer detection rate at 1 year after baseline LDCT scan. Overdiagnosis could have occurred, especially in participants diagnosed with adenocarcinoma in situ. In individuals who do not smoke, our findings suggest that a family history of lung cancer among first-degree relatives significantly increases the risk of lung cancer as well as the rate of invasive lung cancer with increasing age. Further research on risk factors for lung cancer in this population is needed, particularly for those without a family history of lung cancer. FUNDING: Ministry of Health and Welfare of Taiwan.

Performance measures of 8,169,869 examinations in the National Breast Cancer Screening Program in Taiwan, 2004-2020.

BACKGROUND: The benefits of mammographic screening have been shown to include a decrease in mortality due to breast cancer. Taiwan's Breast Cancer Screening Program is a national screening program that has offered biennial mammographic breast cancer screening for women aged 50-69 years since 2004 and for those aged 45-69 years since 2009, with the implementation of mobile units in 2010. The purpose of this study was to compare the performance results of the program with changes in the previous (2004-2009) and latter (2010-2020) periods. METHODS: A cohort of 3,665,078 women who underwent biennial breast cancer mammography screenings from 2004 to 2020 was conducted, and data were obtained from the Health Promotion Administration, Ministry of Health and Welfare of Taiwan. We compared the participation of screened women and survival rates from breast cancer in the earlier and latter periods across national breast cancer screening programs. RESULTS: Among 3,665,078 women who underwent 8,169,869 examinations in the study population, the screened population increased from 3.9% in 2004 to 40% in 2019. The mean cancer detection rate was 4.76 and 4.08 cancers per 1000 screening mammograms in the earlier (2004-2009) and latter (2010-2020) periods, respectively. The 10-year survival rate increased from 89.68% in the early period to 97.33% in the latter period. The mean recall rate was 9.90% (95% CI: 9.83-9.97%) in the early period and decreased to 8.15% (95%CI, 8.13-8.17%) in the latter period. CONCLUSIONS: The evolution of breast cancer screening in Taiwan has yielded favorable outcomes by increasing the screening population, increasing the 10-year survival rate, and reducing the recall rate through the participation of young women, the implementation of a mobile unit service and quality assurance program, thereby providing historical evidence to policy makers to plan future needs.

Complete, Fully Automatic Detection and Classification of Benign and Malignant Breast Tumors Based on CT Images Using Artificial Intelligent and Image Processing.

Breast cancer is the most common type of cancer in women, and early detection is important to significantly reduce its mortality rate. This study introduces a detection and diagnosis system that automatically detects and classifies breast tumors in CT scan images. First, the contours of the chest wall are extracted from computed chest tomography images, and two-dimensional image characteristics and three-dimensional image features, together with the application of active contours without edge and geodesic active contours methods, are used to detect, locate, and circle the tumor. Then, the computer-assisted diagnostic system extracts features, quantifying and classifying benign and malignant breast tumors using a greedy algorithm and a support vector machine. The study used 174 breast tumors for experiment and training and performed cross-validation 10 times (k-fold cross-validation) to evaluate performance of the system. The accuracy, sensitivity, specificity, and positive and negative predictive values of the system were 99.43%, 98.82%, 100%, 100%, and 98.89% respectively. This system supports the rapid extraction and classification of breast tumors as either benign or malignant, helping physicians to improve clinical diagnosis.

Simultaneous Patent Blue Dye Injections Aid in the Preoperative CT-Guided Localization of Multiple Pulmonary Nodules.

Background and Objectives: Clinically, a major challenge of multiple nodule localization is puncture-related pneumothorax, which may hamper the successful localization. This study aims to investigate and compare the efficacy and safety of the simultaneous and sequential patent blue dye (PBD) injections for identifying multiple pulmonary nodules during preoperative CT-guided localization. Materials and Methods: Sixty-one consecutive patients with multiple pulmonary nodules who underwent preoperative CT-guided localization with PBD injections between January 2020 and December 2020 were retrospectively enrolled. Of these patients, 31 patients with 64 nodules who underwent simultaneous injections were designated as the simultaneous group; the remaining 30 patients with 63 nodules who underwent sequential punctures were designated as the sequential group. The clinical and radiological features, technical information, pathological results, and procedure-related variables and complications of the two groups were reviewed and analyzed. Results: The localization success rate of the simultaneous group was higher than that of the sequential group (100% [64/64] vs. 93.7% [59/63], p = 0.041). The incidences of pneumothorax (32.3 vs. 33.3%, p = 0.929) and pulmonary hemorrhage (6.3 vs. 3.0%, p = 1) were not significantly different between the two groups, and all cases were minor, which did not require further intervention. Additionally, a significantly lower radiation dose (2.7 vs. 3.5 mSv, p = 0.001) and a shorter procedure time (20.95 vs. 25.28 min, p = 0.001) were observed in the simultaneous group than in the sequential group. Conclusions: Compared with the sequential method, simultaneous PBD injections may improve the localization success rate with a shorter procedure time and less radiation exposure if the patient with multiple pulmonary nodules can be approached in a single position. Further prospective studies are needed to validate these results.

Detection of Left Ventricular Systolic Dysfunction Using an Artificial Intelligence-Enabled Chest X-Ray.

BACKGROUND: Assessment of left ventricular systolic dysfunction provides essential information related to the prognosis and management of cardiovascular diseases. The aim of this study was to develop a deep-learning model to identify left ventricular ejection fraction (LVEF) ≤ 35% via chest X-ray (CXR [CXR-EF≤35%]) features and investigate the performance and clinical implications. METHODS: This study collected 90,547 CXRs with the corresponding LVEF according to transthoracic echocardiography from the outpatient department in an academic medical center. Among these, 77,227 CXRs were used to develop the identification of CXR-EF≤35%. Another 13,320 CXRs were used to validate the performance, which was evaluated by area under the receiver operating characteristic curve (AUC). Furthermore, CXR-EF≤35% was tested to assess the long-term risks of developing LVEF ≤ 35% and cardiovascular outcomes, which were evaluated by Kaplan-Meier survival analysis and the Cox proportional hazards model. RESULTS: The AUCs of CXR-EF≤35% for the detection of LVEF ≤ 35% were 0.888 and 0.867 in the internal and external validation cohorts, respectively. Patients with baseline LVEF > 50% but detected as CXR-EF≤35% were at higher risk of long-term development of LVEF ≤ 35% (hazard ratio, internal validation cohort [HRi] 3.91, 95% CI 2.98-5.14; hazard ratio, external validation cohort [HRe] 2.49, 95% CI 1.89-3.27). Furthermore, patients detected as LVEF ≤ 35% by CXR-EF≤35% had significantly higher future risks of all-cause mortality (HRi 1.40, 95% CI 1.15-1.71; HRe 1.38, 95% CI 1.15-1.66), cardiovascular mortality (HRi 3.02, 95% CI 1.84-4.98; HRe 2.60, 95% CI 1.77-3.82), and new-onset atrial fibrillation (HRi 2.81, 95% CI 2.15-3.66; HRe 2.93, 95% CI 2.34-3.67) compared with those detected as no LVEF ≤ 35%. CONCLUSIONS: CXR-EF≤35% may serve as a screening tool for early detection of LVEF ≤ 35% and could independently contribute to predictions of long-term development of LVEF ≤ 35% and cardiovascular outcomes. Further prospective studies are needed to confirm the model performance.

Median Nerve Injury in Ultrasound-Guided Hydrodissection and Corticosteroid Injections for Carpal Tunnel Syndrome.

PURPOSE: Permanent nerve damage after corticosteroid injection has been suggested when symptoms of median nerve injury (MNI) are irreversible. We assess the outcomes of MNI and their association with ultrasonography (US)-guided hydrodissection and the following corticosteroid injection for symptomatic carpal tunnel syndrome (CTS). METHODS: US-guided hydrodissection and the following corticosteroid injections were administered to 126 CTS patients. Occurrence of MNI, clinical data, and post-hydrodissection findings were evaluated. Post-hydrodissection findings included vascular injury during hydrodissection, altered echogenicity, reduced flattening ratio, and increased cross-sectional area of the MN at the inlet of the carpal tunnel (MN-CSA-Inlet) on ultrasonography after hydrodissection. The relevance of MNI with respect to these clinical data and findings was determined. The outcome was rated using Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) scores. RESULTS: Nine patients suffered MNI (incidence, 7.1 %) but improved significantly at follow-up. Clinical data and vascular injury during hydrodissection, altered echogenicity, and reduced flattening ratio after hydrodissection were unrelated to prolonged transient MNI (p > 0.05). MNI was significantly associated with increased CSA (p = 0.005). A CSA increase > 2 mm2 after hydrodissection yielded the greatest performance (0.979) for MNI in the receiver operating characteristic analysis. Decreases in BCTQ scores after injection did not differ significantly between groups with and without MNI (p > 0.05). CONCLUSION: MNI during hydrodissection may be reversible. MNI is indicated by an increase in MN-CSA-inlet immediately after hydrodissection.

Transcatheter Arterial Chemoembolization with Drug-Eluting Beads for the Treatment of Hepatocellular Carcinoma: Recommended Selection for Small-Caliber (<100 µm) Beads.

Drug-eluting beads transarterial chemoembolization (DEB-TACE) is an alternative to conventional lipiodol-based TACE (cTACE) to treat hepatocellular carcinoma (HCC). With the advancement in pharmacology, small-caliber DEB-TACE (<100 µm) has been introduced since 2016. For the treatment of hepatic neoplasms or HCC, there is a tendency to use smaller beads by DEB-TACE to achieve more extensive tumor necrosis and a significant reduction in liver toxicity in comparison with that caused by cTACE. However, the indications and potential complications of small-caliber DEB-TACE remain uncertain and have not been well established, due to lack of randomized phase III clinical trials. Instead of systematic or meta-analysis review, this narrative review article describes the suggested indications and contraindications of DEB-TACE with small DEBs, benefit of super-selective embolization of the feeding arteries and the recommended selection of small-caliber DEB. This review was approved by the institutional review board (File Number: 1-105-05-158).

Dynamic magnetic resonance imaging features of cavernous hemangioma in the manubrium: A case report.

BACKGROUND: Osseous hemangiomas, especially those located in the manubrium, are rare benign tumors. In a review of the literature, only three case reports of sternal hemangioma were found. A precise diagnosis is difficult because of their nonspecific findings on computed tomography (CT)/magnetic resonance imaging (MRI). CASE SUMMARY: An 88-year-old woman was suffering from a progressively enlarging mass in the manubrium. Chest CT images showed an osteolytic and expansile lesion with cortical destruction. Vascular malformation was suspected after CT-guided biopsy. On the dynamic MRI scans, the mass showed a bright signal on the T2-weighted image, peripheral nodular enhancement on the early-phase images and progressive centripetal fill-in on the delayed-phase images. Cavernous hemangioma was suspected preoperatively based on the MRI features and finally confirmed by histopathologic analysis. CONCLUSION: This uncommon case demonstrates the possible characteristic features of manubrium cavernous hemangioma on dynamic MRI scans; knowledge about these features may prevent patients from developing catastrophic complications, such as rupture or internal hemorrhage, caused by biopsy or surgery.

Differentiating focal interstitial fibrosis from adenocarcinoma in persistent pulmonary subsolid nodules (> 5 mm and < 20 mm): the role of coronal thin-section CT images.

OBJECTIVES: To investigate thin-section computed tomography (CT) features of pulmonary subsolid nodules (SSNs) with sizes between 5 and 20 mm to determine predictive factors for differentiating focal interstitial fibrosis (FIF) from adenocarcinoma. METHODS: From January 2017 to December 2018, 169 patients who had persistent SSNs 5-20 mm in size and underwent preoperative nodule localization were enrolled. Patient characteristics and thin-section CT features of the SSNs were reviewed and compared between the FIF and adenocarcinoma groups. Univariable and multivariable analyses were used to identify predictive factors of malignancy. Receiver operating characteristic (ROC) curve analysis was used to quantify the performance of these factors. RESULTS: Among the 169 enrolled SSNs, 103 nodules (60.9%) presented as pure ground-glass opacities (GGOs), and 40 (23.7%) were FIFs. Between the FIF and adenocarcinoma groups, there were significant differences (p< 0.05) in nodule border, shape, thickness, and coronal/axial (C/A) ratio. Multivariable analysis demonstrated that a well-defined border, a nodule thickness >4.2, and a C/A ratio >0.62 were significant independent predictors of malignancy. The performance of a model that incorporated these three predictors in discriminating FIF from adenocarcinoma achieved a high area under the ROC curve (AUC, 0.979) and specificity (97.5%). CONCLUSIONS: For evaluating persistent SSNs 5-20 mm in size, the combination of a well-defined border, a nodule thickness > 4.2, and a C/A ratio > 0.62 is strongly correlated with malignancy. High accuracy and specificity can be achieved by using this predictive model. KEY POINTS: • Thin-section coronal images play an important role in differentiating FIF from adenocarcinoma. • The combination of a well-defined border, nodule thickness>4.2 mm, and C/A ratio >0.62 is associated with malignancy. • This predictive model may be helpful for managing persistent SSNs between 5 and 20 mm in size.

Post-operative assessment in patients after liver transplantation: imaging parameters associated with 1-year graft failure.

PURPOSE: To identify post-liver transplant CT findings which predict graft failure within 1 year. MATERIALS AND METHODS: We evaluated the CT scans of 202 adult liver transplants performed in our institution who underwent CT within 3 months after transplantation. We recorded CT findings of liver perfusion defect (LPD), parenchymal homogeneity, and the diameters and attenuations of the hepatic vessels. Findings were correlated to 1-year graft failure, and interobserver variability was assessed. RESULTS: Forty-one (20.3%) of the 202 liver grafts failed within 1 year. Graft failure was highly associated with LPD (n = 18/25, or 67%, versus 15/98, or 15%, p < 0.001), parenchymal hypoattenuation (n = 20/41, or 48.8% versus 17/161, or 10.6%, p < 0.001), and smaller diameter of portal veins (right portal vein [RPV], 10.7 ± 2.7 mm versus 14.7 ± 2.2 mm, and left portal vein [LPV], 9.8 ± 3.0 mm versus 12.4 ± 2.2 mm, p < 0.001, respectively). Of these findings, LPD (hazard ratio [HR], 5.43, p < 0.001) and small portal vein diameters (HR, RPV, 3.33, p < 0.001, and LPV, 3.13, p < 0.05) independently predicted graft failure. All the measurements showed fair to moderate interobserver agreement (0.233~0.597). CONCLUSION: For patients who have CT scan within the first 3 months of liver transplantation, findings of LPD and small portal vein diameters predict 1-year graft failure. KEY POINTS: •Failed grafts are highly associated with liver perfusion defect, hypoattenuation, and small portal vein. •Right portal vein < 11.5 mm and left portal vein < 10.0 mm were associated with poor graft outcome. •Liver perfusion defect and small portal vein diameter independently predicted graft failure.

Time to peak enhancement of malignant hypervascular hepatic tumors versus that of the aorta evaluating by test bolus sequence of magnetic resonance imaging.

PURPOSE: To determine the relationship between time to peak enhancement (TPE) of malignant hypervascular hepatic tumors and that of the aorta. METHOD: Sixty patients with malignant hypervascular hepatic tumors (48 with hepatocellular carcinoma and 12 with metastatic neuroendocrine tumor) who received abdominal MRI with test bolus sequence between January 2015 and May 2019 were enrolled. The test bolus images were monitored every 3 s after the injection of 2 mL gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) and 10 mL saline flush, to evaluate the TPE of the tumors and aorta. We used linear regression with a least squares approach to show the relationship between TPE of the malignant hypervascular hepatic tumors and that of the aorta. RESULTS: TPE of malignant hypervascular hepatic tumors and abdominal aorta were 43.4 ±â€¯12.9 and 23.3 ±â€¯7.4 s, respectively (mean ±â€¯standard deviation). In univariate regression analysis, the TPE of malignant hypervascular hepatic tumors have a positively linear correlation with that of the aorta by the following equation: (TPE of malignant hypervascular hepatic tumor) = 1.4 X (TPE of the aorta) + 10.6 s (r = 0.65, p < 0.005). CONCLUSIONS: TPE of malignant hypervascular hepatic tumors can be predicted by a simple linear transformation from that of the aorta.

Consensus survey on pre-procedural safety practices in radiological examinations: a multicenter study in seven Asian regions.

OBJECTIVE: To understand the status of pre-procedural safety practices in radiological examinations at radiology residency training institutions in various Asian regions. METHODS: A questionnaire based on the Joint Commission International Accreditation Standards was electronically sent to 3 institutions each in 10 geographical regions across 9 Asian countries. Questions addressing 45 practices were divided into 3 categories. A five-tier scale with numerical scores was used to evaluate safety practices in each institution. Responses obtained from three institutions in the United States were used to validate the execution rate of each surveyed safety practice. RESULTS: The institutional response rate was 70.0% (7 Asian regions, 21 institutions). 44 practices (all those surveyed except for the application of wrist tags for identifying patients with fall risks) were validated using the US participants. Overall, the Asian participants reached a consensus on 89% of the safety practices. Comparatively, most Asian participants did not routinely perform three pre-procedural practices in the examination appropriateness topic. CONCLUSION: Based on the responses from 21 participating Asian institutions, most routinely perform standard practices during radiological examinations except when it comes to examination appropriateness. This study can provide direction for safety policymakers scrutinizing and improving regional standards of care. ADVANCES IN KNOWLEDGE: This is the first multicenter survey study to elucidate pre-procedural safety practices in radiological examinations in seven Asian regions.

Preparedness and Best Practice in Radiology Department for COVID-19 and Other Future Pandemics of Severe Acute Respiratory Infection.

The COVID-19 global pandemic has emerged as an unprecedented health care crisis. To reduce risks of severe acute respiratory syndrome coronavirus 2 transmission in the Radiology Department, this article describes measures to increase the preparedness of Radiology Department, such as careful screening of staff and patients, thorough disinfection of equipments and rooms, appropriate use of personal protection equipment, and early isolation of patients with incidentally detected computed tomography findings suspicious for COVID-19. The familiarity of radiologists with clinical and imaging manifestations of COVID-19 pneumonia and their prognostic implications is essential to provide optimal care to patients.

Predictive imaging for tumor response to drug-eluting microsphere transarterial chemoembolization in patients with BCLC-C advanced hepatocellular carcinoma.

Drug-eluting microsphere transarterial chemoembolization (DEM-TACE) has been introduced to ensure more sustained and tumor-selective drug delivery for permanent embolization of HCC. The aim of this study was to determine the imaging characteristics that related to favourable treatment response in BCLC-C HCC patients treated with DEM-TACE. In total, 64 patients with BCLC-C HCC that treated with DEM-TACE using doxorubicin-eluted microspheres were retrospectively included. The images were assessed at baseline and at 4-12 weeks follow-up after receiving DEM-TACE. Pre- and post-procedural imaging characteristics were analysed by two independent radiologists and treatment response was evaluated using the modified Response Evaluation Criteria in Solid Tumors criteria. Multivariate analysis showed that vascular lake phenomenon (OR = 5.94, p = 0.03*), and homogeneous tumor enhancement (HTE) on cone-beam computed tomography (CBCT) during angiography (OR = 11.66, p < 0.001*) are associated with better radiological response. In contrast, residual tumor blush (OR = 0.11, p < 0.001*) is associated with worse radiological response. In conclusion, the initial tumor burden <50% (p = 0.012*) and HTE on CBCT (p = 0.040*) are good predictors for locoregional tumor control in patients with advanced HCCs, which can potentially improve patients' outcome.

Prognostic Significance of Apparent Diffusion Coefficient in Hepatocellular Carcinoma Patients treated with Stereotactic Ablative Radiotherapy.

The role of diffusion-weighted magnetic resonance imaging (DW MRI) in assessing durable tumor control for patients with hepatocellular carcinoma (HCC) treated with stereotactic ablative radiotherapy (SABR) was not defined. This retrospective study included 34 HCC patients with 45 lesions who had DW MRI data at baseline and within 6 months post-SABR. On the first post-SABR MRI, 13 lesions (28.9%) had a complete response (CR), 12 (26.7%) had a partial response (PR), 17 (37.8%) had stable disease, and 3 (6.7%) had progressive disease by modified Response Evaluation Criteria in Solid Tumors (mRECIST). On subsequent imaging, the response rate improved from 55.6% to 75.6%. The apparent diffusion coefficients (ADCs) (mean ± standard deviation) pre- and post-SABR were 1.43 ± 0.28 and 1.72 ± 0.34 (×10-3 mm2/s), respectively (p < 0.001). An ADC change ≥25% (DW[+]) was identified as a predictor of favorable in-field control (IFC) (1-year IFC, 93.3% vs. 50.0% for DW[-], p = 0.004), but an mRECIST-based positive response (CR and PR) at the first MRI was not (p = 0.130). In conclusion, ADC change on early MRI is closely related to IFC in HCCs treated with SABR. Standardization of the DW MRI protocol, as well as prospective validation studies, are warranted.

Association between acute aortic dissection and the distribution of aortic calcification.

OBJECTIVE: Aortic calcification (AC) is associated with increased risks of cardiovascular events and mortality. Numerous studies have explored the association between calcification and abdominal artery aneurysm. However, evidence regarding the association between AC and acute aortic dissection (AAD) is limited. We aimed to evaluate the association between AC-related variables and the development of intimal tear (IT) in patients with AAD. METHODS: We conducted a retrospective observational study involving 64 patients with type A AAD and 32 patients with type B AAD from February, 2011 to January, 2017 at a tertiary referral medical center in Taiwan. We used the default analysis module "calcification score analysis" to calculate all the calcification variables, including AC scores and volume. RESULTS: We identified an association between AC and AAD. Patients with AAD had a greater AC volume in the aortic arch and greater AC scores for both the ascending aorta and the aortic arch than did patients without AAD. However, hypertension and coronary artery disease, rather than AC remained to be the independent risk factor for AAD in multivariate analysis. Patients with type A AAD had greater mean and cumulative AC volumes in the aortic arch, greater cumulative AC volumes in the whole aorta and higher cumulative AC scores in the aortic arch than did patients with type B AAD. ACs were superimposed on ITs in nearly half of the patients with AAD. In patients with type A AAD, AC was more commonly located distal to the IT and farther from the IT. CONCLUSIONS: We identified the associations between AC-related variables and the location of IT in patients with AAD. However, AC was not an independent risk factor for AAD. The distribution of AC was different between patients with type A and type B AAD.

A simple and efficient method to perform preoperative pulmonary nodule localization: CT-guided patent blue dye injection.

OBJECTIVE: To assess the efficacy of computed tomography (CT)-guided localization with the injection of a low dose of patent blue dye (PBD) for the thoracoscopic resection of pulmonary nodules. MATERIALS AND METHODS: Overall, 125 consecutive patients underwent CT-guided localization with injection of a lower dose of PBD between June 2015 and June 2016. The total injection dose relative to the distance between nodules and the visceral pleura was recorded. The clinical and radiological characteristics, technical details, pathological results and procedure-related complications were reviewed. RESULTS: A total of 137 indeterminate pulmonary nodules were identified. The mean nodule size was 9.5 (3.0-22.0) mm. The mean injection dose of PBD relative to the distance between nodules and the visceral pleura was classified as follows: 0.07 ml: <1 cm, 0.1 ml: 1-2 cm and 0.18 ml: >2 cm. The mean time of CT-guided localization was 16.5 (10-50) min. The mean time interval from localization to surgery was 188 (24-1440) min. Pneumothorax developed in 50 patients (40%), and focal parenchymal hemorrhage occurred in 16 patients (12.8%) after localization. No patient required chest tube placement or emergent resuscitation. The success rate of dye marking was 98.5% (135/137). Malignancies, including 82 lung cancers, were diagnosed in 97 nodules (70.8%). CONCLUSION: The injection of a lower dose PBD based on the distance to the visceral pleura can be successful with nodular localization and may facilitate thoracoscopic surgery, even in cases with a long interval from localization to surgery.