Yasuji Oshiro

Intrapulmonary lymph nodes: thin-section CT features of 19 nodules.

Purpose The purpose of this study was to describe the thin-section CT features of intrapulmonary lymph nodes that accompanied primary or metastatic lung tumors. Method A retrospective analysis of thin-section CT features was performed on 19 nodules in 16 patients with pathologically confirmed intrapulmonary lymph nodes that accompanied primary or metastatic lung tumors. Results Of the 16 patients, 13 had a solitary nodule and 3 had two nodules. All nodules were distributed in the middle lobe, lingula, or lower lobe. On thin-section CT images, the nodule was located abutting the visceral pleura (n = 10) or within 8 mm of the visceral pleura (n = 9). The thin-section CT findings showed that most of the nodules were well circumscribed (n = 18), homogeneous (n = 19), ovoid (n = 10), or round (n = 9) and smaller than 12 mm in maximal diameter. The surrounding lung field was normal (n = 16). Conclusion Intrapulmonary lymph nodes are subpleural in the lower lung field. On thin-section CT, they are well circumscribed, homogeneous, round or ovoid, and smaller than 12 mm in maximal diameter. In the differential diagnosis of subpleural nodules located in the lower lung field, it should be kept in mind that they may be intrapulmonary lymph nodes even though the patient has malignancy.

Measurement of Focal Ground-glass Opacity Diameters on CT Images: Interobserver Agreement in Regard to Identifying Increases in the Size of Ground-Glass Opacities

PURPOSE To evaluate interobserver agreement in regard to measurements of focal ground-glass opacities (GGO) diameters on computed tomography (CT) images to identify increases in the size of GGOs. MATERIALS AND METHODS Approval by the institutional review board and informed consent by the patients were obtained. Ten GGOs (mean size, 10.4 mm; range, 6.5-15 mm), one each in 10 patients (mean age, 65.9 years; range, 58-78 years), were used to make the diameter measurements. Eleven radiologists independently measured the diameters of the GGOs on a total of 40 thin-section CT images (the first [n = 10], the second [n = 10], and the third [n = 10] follow-up CT examinations and remeasurement of the first [n = 10] follow-up CT examinations) without comparing time-lapse CT images. Interobserver agreement was assessed by means of Bland-Altman plots. RESULTS The smallest range of the 95% limits of interobserver agreement between the members of the 55 pairs of the 11 radiologists in regard to maximal diameter was -1.14 to 1.72 mm, and the largest range was -7.7 to 1.7 mm. The mean value of the lower limit of the 95% limits of agreement was -3.1 ± 1.4 mm, and the mean value of their upper limit was 2.5 ± 1.1 mm. CONCLUSION When measurements are made by any two radiologists, an increase in the length of the maximal diameter of more than 1.72 mm would be necessary in order to be able to state that the maximal diameter of a particular GGO had actually increased.

Pulmonary dirofilariasis: Computed tomography findings and correlation with pathologic features

Objective: The purpose of this study was to describe the computed tomography (CT) and pathologic features of 5 nodules of pulmonary dirofilariasis in 4 patients. Methods: Four patients with 5 nodules of pathologically confirmed pulmonary dirofilariasis who under went CT were enrolled, and the imaging interpretations were retrospectively compared with the histopathologic characteristics. Results: Three of the 4 patients had a solitary nodule, and the remaining patient had 2 nodules. All the nodules were distributed in the right lower lobe and were attached to the pleura. They were all round or oval in shape and ranged in size from 11 to 22 mm in largest diameter (mean = 17 mm). On thinner section CT, the nodules had a well-defined smooth margin with or without a shallow notch; they were connected to the arterial branch and, occasionally, to the venous branch. On contrast-enhanced CT, all the nodules contained a homogeneous low-attenuation area, which corresponded to areas of coagulative necrosis on histopathologic examination. Conclusion: Although the CT findings of a pulmonary dirofilariasis nodule are nonspecific, awareness of the findings on contrast-enhanced CT and the pathologic appearance of this rare benign condition may facilitate its differentiation from a malignant nodule.

Risk factor of radiation pneumonitis: assessment with velocity-encoded cine magnetic resonance imaging of pulmonary artery.

Objective: The aim of this study was to investigate whether the pulmonary arterial flow obtained as a function of time from velocity-encoded cine (VEC) magnetic resonance (MR) imaging can be used to predict radiation pneumonitis. Methods: Before receiving radical radiotherapy, 19 patients with primary lung cancer and 21 with primary esophageal cancer underwent VEC MR imaging to determine their pulmonary arterial flow. The right and left pulmonary arterial flow profiles were digitized, and from these data, acceleration time, maximal change in flow rate during ejection, acceleration volume, and the ratio of maximal change in flow rate during ejection to acceleration volume were measured. The statistical significance of differences in pulmonary arterial flows before irradiation between patients who developed and did not develop RP greater than grade 1 was determined. Results: Radiation pneumonitis occurred in 5 patients with lung cancer and in 4 with esophageal cancer. The acceleration time (P < 0.001), acceleration volume (P < 0.02), and ratio of the maximal change in flow rate during ejection to acceleration volume (P < 0.002) in patients with and without RP were significantly different. The sensitivity, specificity, and accuracy of using 111 milliseconds as the cutoff value (which was the mean acceleration time in the RP group) to predict RP were 58%, 88%, and 83%, respectively. Conclusions: Pulmonary hypertension detected by VEC MR imaging can be a risk factor for development of RP in candidates for pulmonary irradiation.

Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

Purpose The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner. Results The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU]) was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001). The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001) for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures. Conclusion Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners.

Addison’s disease due to tuberculosis that required differentiation from SIADH

A 77-year-old man was admitted to our hospital complaining of general fatigue. Serum sodium was 116 mEq/l and serum antidiuretic hormone (ADH) was elevated. Radiologic examination revealed nodules in the brain as well as in both adrenal glands. Based on the findings of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET), we had considered that the cause of the hyponatremia was syndrome of inappropriate secretion of antidiuretic hormone (SIADH) due to active extrapulmonary tuberculosis. Against our expectations, the patient’s condition got worse just after he began antituberculous therapy; we finally diagnosed Addison’s disease by additional hormonal tests. His condition recovered immediately with the administration of high-dose hydrocortisone, and the tuberculous lesions became smaller with antituberculous medications. Although tuberculous Addison’s disease has been decreasing markedly in recent years, we have to consider the possibility of adrenal insufficiency when hyponatremia is observed in patients with active tuberculosis or those having a past history of tuberculosis.

Subcarinal air cysts: multidetector computed tomographic findings.

Objective: The purpose of this study was to assess the computed tomographic (CT) features of subcarinal air cysts, which may be related to bronchial diverticula. Method: Seven patients with subcarinal air cysts were retrospectively identified. The following CT features were assessed: location, size, and marginal characteristics of subcarinal air cysts; number, location, and size of communication between the air cyst and bronchi if present; presence of bronchial diverticula in any other location; presence of the pulmonary lesion; and interval change of subcarinal air cysts on follow-up CT. Results: The air cysts were located inferior or inferoposterior to the carina. The subcarinal air cysts typically had a lobulated margin and demonstrated ductlike communications between the air cyst and bronchi. Ductlike communications arose from the posterointerior aspect of the proximal side of main bronchi and were either solitary or multiple. The larger subcarinal air cysts tended to be multiloculated. Conclusions: Subcarinal air cysts may be considered as part of a spectrum of conditions, which include bronchial diverticula and right paratracheal air cysts. Because of their predictable location and appearance, they should be easily distinguished from pathologic lesions such as pneumomediastinum.

Simultaneous occurrence of partial anomalous pulmonary venous return and major bronchial anomaly: computed tomography findings in 5 adult patients.

Objective: The objective of this study was to describe the computed tomography (CT) findings of 5 adult patients with a combination of partial anomalous pulmonary venous return (PAPVR) and major bronchial anomaly. Methods: A computerized search of the radiological database records of 4886 consecutive patients who underwent chest CT from April 2005 to May 2007 described 2 patients with a combination of PAPVR and tracheal bronchus (TB). Three additional patients with a combination of PAPVR and TB or accessory cardiac bronchus (ACB) were obtained by reviewing the CT images of the patients initially diagnosed as having PAPVR, TB, or ACB at our institution during the same period. The CT findings of these 5 patients were analyzed. Results: Four patients had a combination of right PAPVR and right TB, and 1 patient had a combination of left PAPVR and ACB. These combinations were found in 42% (5/12) of patients with PAPVR, 16% (4/25) of patients with TB, and 14% (1/7) of patients with ACB. In 4 patients with a combination of right PAPVR and right TB, the anomalous vein was draining the right upper lobe and draining into either the posterior aspect of the superior vena cava (SVC) or the terminal portion of the azygos arch. The origin of the TB was the trachea in 1 patient and the carina in 2 patients. Two distinct TBs presented in 1 patient; the first TB was from the lower trachea, and the second was from the right main bronchus. The right upper lobe affected by PAPVR included the territory ventilated by the TB in all 4 patients. Conclusion: A combination of right PAPVR draining to the superior vena cava or azygos arch and right TB is most common. The possibility that the PAPVR and a major bronchial anomaly might coexist in 1 patient should be considered whenever either of them is encountered on CT.

CT findings of a displaced left upper division bronchus in adults: Its importance for performing safe left pulmonary surgery

PURPOSE The aim of this study was to describe the CT findings of a displaced left upper division bronchus (DLUDB) in adults. MATERIALS AND METHODS Ten patients with DLUDB were identified. The following CT features were assessed: origin of the DLUDB; distance between the origin of the DLUDB and the origin of the left upper lobe (LUL) bronchus; height of the origin of the DLUDB against the left pulmonary artery (LPA); difference of the main bronchial length; ventilated segment; course of the left pulmonary artery against the DLUDB; and presence of an accessory fissure or other anomalies. RESULTS DLUDB arose from the posterolateral or lateral aspect of the left main bronchus immediately proximal to the origin of the LUL bronchus. It tended to course along the posterior wall of the LPA and to ventilate the apicoposterior segment with or without the anterior segment. The LPA passed between the displaced bronchus and the lingular bronchus. The origin of the DLUDB was located lower than the inferior wall of the proximal LPA in 6 patients. The accessory fissure between the associated segment and remaining part of the LUL and right tracheal bronchus coexisted in 7 and 3 patients respectively. CONCLUSION DLUDB has characteristic findings on CT. Radiologists should be aware of this entity and inform the surgeon as it can prevent serious complications in a patient who may undergo lobectomy of the left lung.

Partial Anomalous Pulmonary Venous Connection Coexisting with Lung Cancer: A Case Report and Review of Relevant Cases from the Literature

A 45-year-old man had an abnormal shadow in the right lung field on an annual screening chest X-ray. He was diagnosed with Stage IA (cT1bN0M0) lung cancer. Initially, we did not notice an anomalous vein on non-contrast computed tomography. However, we found that the right upper lobe bronchus branched from the lateral wall of the right main bronchial orifice, above the level of the common right upper lobe bronchus. Therefore, the bronchus was thought to be a tracheal bronchus. We carefully reevaluated the patient using three-dimensional computed tomography angiography. This technique showed that the anomalous right superior pulmonary vein drained into the azygos vein along the superior vena cava. These findings confirmed a partial anomalous pulmonary venous connection of the right upper lobe. We performed video-assisted thoracoscopic right upper lobectomy and mediastinal lymph node dissection for definitive treatment for lung cancer and partial anomalous pulmonary venous connection. No hemodynamic problems occurred in the postoperative course.