Introduction: Pulmonary hypertension has been associated with a significant increase in morbidity and mortality. The pulmonary artery diameter measurement from a CT scan is routinely used to predict possible evidence of pulmonary hypertension. However, no data available as a reference for the normal range, especially in the Thai Population. The primary purpose of this study was to determine the normal diameter of the main pulmonary artery (MPA) and ascending aorta (AAo) and the ratio between MPA and AAo diameter in the Thai population. Methods: Patients who met the inclusion criteria and had a chest CT performed in Songklanagarind hospital between 1 January 2014 and 14 July 2014 were enrolled. Measurement of the MPA diameter at the level of its bifurcation and the AAo from an axial-view contrast-enhanced CT chest (venous phase) image was done. The ratio between the diameter of MPA and AAo was then calculated. Results: 2395 patients were included in this study (male = 1271 patients, female = 1124 patients, aged between 20-96 years; mean = 57 years old). The mean diameter of the MPA was 25.21 mm, and the mean diameter of the AAo was 30.78 mm. The mean MPA/ AAo ratio was 0.83. The sex-specific mean diameters of the MPA were 25.4 mm in men and 25.0 mm in women. The mean diameters of the AAo in men and women were 31 mm and 30 mm, respectively.Conclusion: The mean MPA diameter obtained from chest CT scans in this study was about 25.4 mm in men and 25.0 mm in women. These values are easily obtained from chest CT scans and are highly reproducible. Therefore, it may be used as a reference value for a healthy Thai population.

Esophageal leiomyoma is uncommon. However, this tumor is the most common subepithelial tumor affecting the esophagus, comprising approximately two-thirds of benign esophageal tumors. Leiomyomas of the esophagus rarely cause symptoms when they are single and <5 cm. The mainstay of treatment is esophagectomy for symptomatic patients. A 68-year-old male patient presented with progressive dysphagia for 4 months. The degree of dysphagia and chest discomfort was more severe on solid rather than liquid diet. The CT scan of the chest showed multiple well-defined, submucosal nodules, up to 1.9 cm in diameter located at the middle esophagus. The barium swallow study illustrated multiple, well-defined, smooth, semilunar filling defects along the mid to distal esophagus. Meanwhile, esophagogastroduodenoscopy revealed 8 smooth subepithelial masses. Moreover, the radial EUS showed multiple hypoechoic masses arising from the 4th layer, with some of the tumors connected to others as a horseshoe-like shape causing narrowed lumen. Last, high-resolution esophageal manometry revealed ineffective esophageal motility. We report a rare case of numerous esophageal leiomyomas which caused dysphagia as a result of both mechanical obstruction and hypomotility disorder. The histopathology confirmed the diagnosis of esophageal leiomyoma. Symptoms improved significantly after lifestyle modifications and adherence to dietary advice on the part of the patient.

Background Identification of normal variations to the thoracic central venous system anatomy is essential in radiological intervention and cardiothoracic surgery to prevent complications. Purpose To estimate the prevalence and pattern of normal variations of superior vena cava (SVC) and azygos venous system as well as factors associated with normal variations of SVC. Material and Methods Venous-phase chest CT of 1336 patients were retrospectively reviewed. Age, sex, and underlying disease were recorded. SVC diameter and cross-sectional area were measured to evaluate for associations with normal variations. Results The prevalence of normal anatomical variations of SVC and azygos venous system were 0.3% and 1.5%, respectively. Duplicated SVC was the most common variations. The most common variation for the azygos venous system was the connection between the hemiazygos and accessory hemiazygos veins draining into the left brachiocephalic vein (12/1336 cases, 0.9%). The median (interquartile range [IQR]) cross-sectional area compared between normal SVC (297.2 mm2) and duplicated SVC (223.5 mm2) showed a statistically significant difference ( P = 0.033). Conclusion This study determined the prevalence of rare normal variations of the azygos venous system, a connection between the hemiazygos and accessory hemiazygos veins draining into the left brachiocephalic vein. The prevalence of normal variations of the SVC and azygos venous system in the adult Thai population was similar with that of previous publications. Cross-sectional area was the only factor with a significant association with SVC variations.

Purpose:To evaluate clot size and stenotic degree on conventional computed tomographic pulmonary angiography (CTPA) with perfusion defect. Material and Methods:Fifty-two pulmonary embolism (PE) patients with 144 PE locations underwent dual-energy CTPA with an iodine distribution map. Each PE location was rated as to whether there was a perfusion defect. Clot size, stenotic degree, and other associated PE findings were evaluated. These findings were then correlated with whether the perfusion defect was present.Results: There were no associations between demographics, clinical characteristics, anatomical data, and perfusion defect. The median iodine concentration ratio was 0.11. Imaging interpretation by 2 thoracic radiologists had excellent agreement. The clot size and stenotic degree in PE were significant predictors of perfusion defect on conventional CTPA. Lesions with higher degrees of stenosis had higher percentages of perfusion defect. The generalized estimating equation (GEE) logistic regression confirmed that clot size and stenotic degree could predict PE perfusion defects on conventional CTPA. Conclusions:The 2 significant predictors of perfusion defect were occluded vessels in both small and large branches together, or complete occlusion of the pulmonary artery.