Journal of Thoracic Imaging’s Exciting Growth: New Record 2018 Impact Factor and Welcome to the Asian Society of Thoracic Radiology No abstract available

Postmortem Computed Tomography and Computed Tomography Angiography: Cardiothoracic Imaging Applications in Forensic Medicine With the introduction of modern imaging technology into the forensic field, postmortem imaging, particularly postmortem computed tomography (PMCT), has gained increasing importance in forensic investigations of deaths. In recent years, PMCT, which aims to provide observer-independent, reproducible forensic assessment in a minimally invasive manner, has been incorporated into routine forensic practice in many medicolegal institutions worldwide as a complement to autopsy. To address questions with regard to vascular pathologies, postmortem computed tomography angiography (PMCTA) has been developed and has become a useful tool for exploring the vascular system. Currently, these techniques play roles in screening for potential pathologies for later autopsy confirmation, facilitating focused dissection of the target area, and visualizing lesions that would be difficult or impossible to detect during autopsy. Adequate image interpretation requires knowledge and understanding of postmortem changes in the body and artefacts related to PMCT and PMCTA. This article reviews the PMCT and PMCTA techniques in terms of their indications, applications, advantages, and limitations for cardiothoracic applications. Our findings will enhance readers’ understanding of emerging CT techniques in forensic radiology.

Imaging Evaluation of Lung Transplantation Patients: A Time and Etiology-based Approach to High-resolution Computed Tomography Interpretation Lung transplantation is an established therapeutic option for patients with irreversible end-stage pulmonary disease limiting life expectancy and quality of life. Common indications for lung transplantation include chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, pulmonary arterial hypertension, and alpha-1 antitrypsin deficiency. Complications of lung transplantation can be broadly divided etiologically into surgical, infectious, immunologic, or neoplastic. Moreover, specific complications often occur within a certain time interval following surgery, which can be broadly classified as early (<6 wk), intermediate (6 wk to 6 mo), and late (>6 mo). Thus, each group of complications can further be categorized on the basis of the time continuum from transplantation. Imaging, primarily by high-resolution computed tomography, plays a critical role in early diagnosis of complications after lung transplantation. Early recognition of complications by the radiologist, and initiation of therapy, contributes to improved morbidity and mortality. However, accurate diagnosis is only feasible if one has a thorough understanding of the major etiologic categories of complications and how they relate to the time course since transplantation. We review imaging manifestations of lung transplant complications via a framework that includes the following major etiologic categories: surgical; infectious; immunologic; and neoplastic; and the following time frames: surgery to 6 weeks; 6 weeks to 6 months; and beyond 6 months. We propose this approach as a logical, evidence-based algorithm to construct a narrow, optimal differential diagnosis of lung transplantation complications.

Assessment of Interstitial Lung Disease Using Lung Ultrasound Surface Wave Elastography: A Novel Technique With Clinicoradiologic Correlates Purpose: Optimal strategies to detect early interstitial lung disease (ILD) are unknown. ILD is frequently subpleural in distribution and affects lung elasticity. Lung ultrasound surface wave elastography (LUSWE) is a noninvasive method of quantifying superficial lung tissue elastic properties. In LUWSE a handheld device applied at the intercostal space vibrates the chest at a set frequency, and the lung surface wave velocity is measured by an ultrasound probe 5 mm away in the same intercostal space. We explored LUWSE’s ability to detect ILD and correlated LUSWE velocity with physiological, quantitative, and visual radiologic features of subjects with known ILD and of healthy controls. Materials and Methods: Seventy-seven subjects with ILD, mostly caused by connective tissue disease, and 19 healthy controls were recruited. LUSWE was performed on all subjects in 3 intercostal lung regions bilaterally. Comparison of LUSWE velocities pulmonary function testing, visual assessment, and quantitative analysis of recent computed tomographic imaging with Computer-Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER) software. Results: Sonographic velocities were higher in all lung regions for cases, with the greatest difference in the lateral lower lung. Median velocity in m/s was 5.84 versus 4.11 and 5.96 versus 4.27 (P<0.00001) for cases versus controls, left and right lateral lower lung zones, respectively. LUSWE velocity correlated negatively with vital capacity and positively with radiologist and CALIPER-detected interstitial abnormalities. Conclusions: LUSWE is a safe and noninvasive technique that shows high sensitivity to detect ILD and correlated with clinical, physiological, radiologic, and quantitative assessments of ILD. Prospective study in detecting ILD is indicated.

3-Dimensional Quantification of Composite Pleural Plaque Volume in Patients Exposed to Asbestos Using High-resolution Computed Tomography: A Validation Study Rationale: As pleural plaque has been reported as a risk factor in the occurrence of lung cancer and mesothelioma, a reproducible and precise method of measurement of pleural plaque volume (PPV) is needed to further describe these relationships. The aim of the study was to assess the reproducibility of a 3-dimensional computed tomography (3D-CT) volumetric analysis of PPV in patients with occupational exposure to asbestos. Material and Methods: A total of 28 patients were retrospectively randomly selected from the multicenter APEXS (Asbestos Post Exposure Survey) study, which was held between 2003 and 2005. All patients underwent a 3D-CT scan. Two readers specialized in chest radiology completed the 3D semiautomated quantification of lung volume using dedicated software. They also had to categorize the visual extent of pleural plaque in terms of thickness and circumference. Reproducibility of the continuous PPV variable was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. Reproducibility of categorical variables was assessed using the κ test. Results: Intraobserver reproducibility of PPV was almost perfect (ICC=0.98 [95% interval: 0.97-0.99]), and interobserver reproducibility was very good (ICC=0.93 [0.88-0.97]). At Bland-Altman analysis, the mean differences were 0.1 (limit of agreement: −11.0 to 11.2) and 3.7 cc3 (−17.8 to 25.2), respectively. Visual analysis of both plaque in terms of thickness and circumference were fair to moderate, with κ values ranging from 0.30 to 0.60. Conclusions: 3D semiautomatic quantification of PPV is feasible and reproducible using CT in patients with occupational exposure to asbestos. PPV measurement may be useful to correlate with other asbestos-related disease outcomes and prognosis.

Perinodular Vascularity Distinguishes Benign Intrapulmonary Lymph Nodes From Lung Cancer on Computed Tomography Purpose: A common diagnostic dilemma in the assessment of small pulmonary nodules on computed tomography (CT) is in distinguishing benign intrapulmonary lymph nodes (IPLNs) from small primary pulmonary malignancies. Several CT features have been described of IPLNs, including attachment to a pleural surface. We had observed that IPLNs were often connected to a pulmonary vein and sought to evaluate the utility of this sign in discriminating IPLNs from lung adenocarcinomas. The frequency of other previously described CT signs of IPLNs was also compared with lung adenocarcinomas. Materials and Methods: We retrospectively identified histopathologically proven benign IPLNs (n=62) and small (<15 mm) adenocarcinomas (n=61). CTs were reviewed to assess the number and type of pulmonary blood vessels arising from, or terminating within, these nodules, as well as other CT features of IPLNs (shape, location, and outline). Results: The termination of a pulmonary artery within a nodule was strongly associated with primary lung adenocarcinoma (55.7%), and this was never seen in isolation in IPLNs (0%) (P<0.001). IPLNs were more frequently associated with pulmonary venous connections (93.5%) compared with lung adenocarcinomas (21.3%) (P<0.001). The connection to a pleural surface was observed in both IPLNs (38.7%) and lung adenocarcinomas (37.7%) (P=1.0). Conclusions: We describe a novel imaging marker that can help to differentiate between benign and malignant pulmonary nodules. However, attachment of a nodule to a pleural surface should not be used in isolation to distinguish IPLNs from lung malignancy.

Pulmonary Hypertension Parameters Assessment by Electrocardiographically Gated Computed Tomography: Normal Limits by Age, Sex, and Body Surface Area in a Chinese Population Purpose: Pulmonary hypertension (PH) parameters such as pulmonary artery or right ventricular size can be measured easily on computed tomography (CT). However, there are limited data on electrocardiographically (ECG) gated CT. We sought to determine age-specific and sex-specific normal reference values for PH parameters normalized by body surface area (BSA) using ECG-gated cardiac CT in a Chinese population. Materials and Methods: In total, we enrolled 519 non-PH patients undergoing ECG-gated CT coronary angiography and measured PH parameters, including main pulmonary artery (MPA) and right pulmonary artery (RPA) diameters and distension, the ratio of MPA to ascending aorta (AAO) diameter (MPA/AAO), and the ratio of right ventricular to left ventricular diameter (RV/LV). Maximum MPA and RPA diameters were also normalized to BSA (nMPA, nRPA). Results: Age, sex, BSA, and body mass index (BMI) were variably associated with PH parameters. Age was an independent predictor of all PH parameters. The maximum MPA diameter (26.5±2.7 mm), maximum RPA diameter (20.9±3.0 mm), nMPA (15.8±2.0 mm/m2), nRPA (12.4±2.0 mm/m2), and RV/LV (0.85±0.11) increased with age. MPA/AAO (0.80±0.10), MPA, and RPA distension (25.4%±7.1%; 23.3%±6.7%) correlated negatively with age. Although absolute MPA and RPA diameters were slightly larger in men, women had significantly larger nMPA and nRPA values. MPA and RPA sizes and RV/LV were correlated positively with BSA and BMI. Conclusions: Using ECG-gated cardiac CT, we determined the normal reference values of PH parameters for non-PH adult Chinese patients, and these values were variably influenced by age, sex, BSA, and BMI.

Renal Sympathetic Denervation: Does Reduction of Left Ventricular Mass Improve Functional Myocardial Parameters? A Cardiovascular Magnetic Resonance Imaging Pilot Study Objectives: Left ventricular (LV) hypertrophy in resistant hypertensive patients is associated with a reduced intramyocardial perfusion. Renal sympathetic denervation (RDN) has been shown to reduce blood pressure (BP) and sympathetic tone. We aimed to prospectively investigate the effect of RDN on functional myocardial parameters and myocardial perfusion reserve (MPR) using cardiac magnetic resonance imaging (cMRI) in patients with resistant hypertension. Methods: A total of 15 resistant hypertensive patients (11 male individuals, mean age 62±13 y) were included. Adenosine stress-induced cMRI was performed at baseline, 3, 6, and 12 months after RDN. RDN was performed using a single soft-tip radiofrequency catheter (Symplicity). cMRI semiquantitative perfusion analysis was performed using the upslope of myocardial signal enhancement to derive the myocardial perfusion reserve index. Results: Both systolic-BP and diastolic-BP significantly decreased from 148±14 to 133±14 mm Hg and 87±14 to 80±10 mm Hg, respectively (P<0.05). LV septal wall thickness was significantly reduced (P<0.001). LV ejection fraction and MPR lacked significant trends 12 months after RDN. Conclusions: In this pilot study, RDN significantly reduced LV mass and LV septal wall thickness, as diagnosed by cMRI, with no significant changes in MPR. cMRI may help in diagnosing clinically relevant changes of functional myocardial parameters after interventional therapy in resistant hypertensive patients.

Imaging Spectrum of Double-Outlet Right Ventricle on Multislice Computed Tomography Double-outlet right ventricle is a complex congenital heart disease that encompasses various common and rare subtypes. Surgical management of these patients needs to be individualized owing to extremely variable morphology and hemodynamics. Imaging plays a crucial role in determination and characterization of outflow tract morphology. The assessment of ventricular septal defect routability with identification of associated anomalies has therapeutic implications in these patients. Multislice computed tomography with advanced 3-dimensional postprocessing techniques and dose-reduction strategies is invaluable in defining the anatomy and morphology of double-outlet right ventricle with simultaneous assessment of associated anomalies.

The Azygos Vein From A to Z Congenital and acquired abnormalities of the azygos vein can affect its size and position. Alteration of contrast material flow dynamics of the azygos vein on computed tomography can be an indication of superior vena cava obstruction. Recognition and accurate characterization of abnormalities of the azygos vein on imaging studies is critical to facilitate prompt diagnosis and direct workup when necessary. The main purpose of this article is to illustrate and describe the radiologic features of various congenital and acquired abnormalities affecting the azygos venous system.