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Objective To evaluate the clinical significance of video-assisted thoracic surgery ( VATS) in localization of pulmonary ground-glass opacities( GGOs) by intraoperative ultrasound ( IU ) . Methods An intraoperative ultrasonographic procedure was prospectively performed on 14 patients harboring GGOs of no more than 3 cm in diameter to localize these lesions and achieve adequate margins . Patients were excluded with both asthma and chronic obstructive pulmonary disease from this study inasmuch as the intraoperative ultrasonographic procedure was more difficult to interpret when residual air is present in the lung . The sonographic characteristics of nodules were compared with those from CT and pathology . Results A total of 18 GGOs were successfully identified by intraoperative ultrasonography without any complications .In all instances 13 GGOs were localized in the lung of complet collapse ,and high-quality echo images were obtained . Additionally ,the IU showed that the nodule sizes were similar to those of CT and postoperative pathological specimens( P < 0 .05) . There was significant difference in lung collapse degree , the maximum diameter of CT and the distance from the lesion to the pleura between echo types ( P <0 .05) . The mean operation time was ( 4 .2 ± 2 .7) min . Conclusions Intraoperative ultrasonography can both safely and effectively localize pulmonary GGO in a completely deflated lung . Hence ,ultrasonography may assist surgeons to perform minimally invasive lung resections with clear surgical margins during the treatment of lung GGO .
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Objective To evaluate the sensitivity and optimized scanning parameter of 64-slice spiral CT in detection of pulmonary nodules with different size and density. Methods Three groups of prosthesis nodules with diameter of 2.5～13 mm and different density (soft-tissue, low density, and ground glass opacity,GGO)were taken into the chest phantom equivalent to human tissue,then scanned with Philips Brilliance 64 scanner in standard dose(tube voltage:120 kV, tube current: 250 mAs)and low-dose(tube voltage:120 kV, tube current: 50, 30,and 21mAs) respectively. The radiation dose(CTDIw and DLP) of the scans, Hounsfield unit(HU) and standard deviation(SD) of CT values in different regions of the phantom, and visibility of the nodules was assessed and recorded.Results The radiation dose of 64-slices spiral CT scanning in low-dose(tube current 21～51 mAs) decreased to 8%～20% of which scanning in standard-dose(250 mAs). There was no statistical difference between the CT values in different regions of the phantom (P>0.05), while the SD of CT values was of statistical significantce (P<0.001) and SD increased with the increment of the density under different scanning parameters. None of the nodules besides of GGO nodules with 2.5 mm and 4 mm in size scanned at 21 mAs was invisible. Conclusion GGO nodules of 2.5 mm in diameter can be detected with 64-slice spiral CT using 30 mAs at experimental study, which might be the optimized dose for detecting pulmonary nodules.
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Objective To analyze the image noise and artifact of low-dose chest CT scanning and the distribution pattern. Methods A chest phantom equivalent to human tissue was scanned by 64 slices spiral scanner at standard dose (250 mAs) and low-dose (50, 30,and 21 mAs) respectively, HU in sites of the phantom and SD of which was recorded. 200 patients with pulmonary nodules were scanned at 30 or 21 mAs for minimal length. The relationship between severity of noise and artifact in chest low-dose CT scanning and gender or body mass index (BMI) of the patients, as well as the distribution of noise and artifact was evaluated. Results There was no statistical difference between the HU in sites of the phantom: lung (-777.3-- -758.2 HU, F=0.992, P<0.01), chest wall (107.9--111.3 HU, F=2.044, P>0.05), vertebra (835.6--875.3 HU, F=1.453, P>0.05), while the SD of which was of statistical signification: lung (9.5--29.0 HU, F=108.7, P<0.01), chest wall (10.1--32.4 HU, F=84.3, P<0.01), vertebra (19.2--57.1 HU, F=30.6, P<0.01),tbe SD increased with the decrease of the tube current. There was no statistical difference between male (in which 74 cases no or mild, 17 cases severe)and female (81 cases no or mild, and 28 cases severe)in image noise and artifact in low-dose images (X~2=2.294, P>0.05), and significant difference between groups of different BMI(in BMI<18.5 group, 29 cases no or mild,2 cases severe, in group of 18.5≤BMI<24.0, 120 cases no or mild, 13 cases severe, and in group of BMI≥24.0, 6 cases no or mild, 30 cases severe, X~2=128.274, P<0.01). The noise andartifact was greater in the upper (80 cases no or mild, 38 cases severe, X~2=18.918, P<0.01) and dorsal field (89 cases no or mild, 33 cases severe, X~2=6.760, P<0.05). Conclusions The image noise and artifact was significant in low-dose CT, especially in the dorsal and upper field of the lung, which might be attributed to the distribution of skeleton in the chest. It was recommended that scanning protocol (mAs value) be individualized adjusted in according to the patients BMI.
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Objective To evaluate the diagnosis value of CT through analyzing 11 cases with the rare disease-lung carcinosarcoma.Methods 11 cases of lung carcinosarcoma proved by operation and pathology from 1994-2000 were analyzed.Results Lung carcinosarcoma had the characteristics of both lung cancer and sarcoma. The border of the carcinosarcoma was irregular, it had lobulation or spiculation, just like primary lung cancer. When IV contrast medium was used, it had some sarcoma’s characteristics such as lower density in center of mass. Conclusion CT is a good method to show the characteristics of lung carcinosarcoma. It is important to recognize the CT appearances of lung carcinosarcoma in order to improve diagnostic ability.