Usefulness and complications of computed tomography-guided lipiodol marking for fluoroscopy-assisted thoracoscopic resection of small pulmonary nodules: Experience with 174 nodules

ObjectiveSeveral techniques have been reported for the localization of small pulmonary nodules in thoracoscopic resection. In the present study we examined the usefulness and complications of computed tomography-guided lipiodol marking for thoracoscopic resection in our experience of 174 nodules.MethodsComputed tomography-guided lipiodol marking was performed on 174 nodules less than 30 mm in size. Of these nodules, 45 showed ground-glass opacity images and 129 showed solid images on computed tomography. The mean size of the nodules was 10 ± 6 mm (range, 2-30 mm), and their mean depth from the pleural surface was 10 ± 7 mm (range, 0-30 mm). One to 7 days before thoracoscopy, all of the nodules were marked with 0.4 to 0.5 mL of lipiodol by using computed tomography. The marked nodules were grasped with a ring-shaped forceps during fluoroscopy and resected by means of thoracoscopy.ResultsAll the nodules could be marked and localized by means of fluoroscopy as a clear spot during thoracoscopic surgery. Complications of the marking were chest pain requiring analgesia in 16 (11%) patients, hemosputum in 11 (6%) patients, pneumothorax in 30 (17%) patients, and hemopneumothorax in 1 (0.6%) patient. Eleven (6%) patients with pneumothorax required drainage, and the patient with hemopneumothorax required an emergency operation. No other complications were observed.ConclusionLipiodol marking is a useful, safe, and inexpensive procedure for localizing ground-glass opacity lesions, small pulmonary nodules, or both for thoracoscopic resection

Metalorganic chemical vapor deposition of β-FeSi2 on β-FeSi2 seed crystals formed on Si substrates

We have fabricated a β-FeSi2 film by metalorganic chemical vapor deposition on a Si(001) substrate with β-FeSi2 seed crystals grown by molecular beam epitaxy, and investigated the crystallinity, surface morphology and temperature dependence of photoresponse properties of the β-FeSi2 film. The surface of the grown β-FeSi2 film was atomically flat, and step-and-terrace structure was clearly observed. Multi-domain structure of β-FeSi2 whose average size was approximately 200 nm however was revealed. The photoresponse was obtained in an infrared light region (~ 0.95 eV) at temperatures below 200 K. The external quantum efficiency reached a maximum, being as large as 25% at 100 K when a bias voltage was 2.0 V

Minority-carrier diffusion length, minority-carrier lifetime, and photoresponsivity of β-FeSi2 layers grown by molecular-beam epitaxy

We have epitaxially grown undoped β-FeSi2 films on Si(111) substrates via atomic-hydrogen-assisted molecular-beam epitaxy. β-FeSi2 films grown without atomic hydrogen exhibited p-type conduction with a hole density of over 1019 cm−3 at room temperature (RT). In contrast, those prepared with atomic hydrogen showed n-type conduction and had a residual electron density that was more than two orders of magnitude lower than the hole density of films grown without atomic hydrogen (of the order of 1016 cm−3 at RT). The minority-carrier diffusion length was estimated to be approximately 16 μm using an electron-beam-induced current technique; this value is twice as large as that for β-FeSi2 prepared without atomic hydrogen. This result could be well explained in terms of the minority-carrier lifetimes measured by a microwave photoconductance decay technique. The 1/e decay time using a 904 nm laser pulse was approximately 17 μs, which is much longer than that for β-FeSi2 prepared without atomic hydrogen (3 μs). The photoresponsivity reached 13 mA/W at 1.31 μm, which is the highest value ever reported for β-FeSi2 films