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Objective To preliminarily investigate the optimum scheme of thyroid CT flat scanning plan,to reduce the artifacts and the radiation dosage.Methods Patients who were involved in this research with thyroid CT flat scanning were divided into three groups:group A (conventional scan group),group B (dosage- reduced group)and group C (a combination of body posture change and dosage reduction).In group A (50 patients),the patients’bilateral arms were naturally drooped on both sides of the body during scanning (scan parameters:120 kV,250 mA).In group B (50 patients),the patients were scanned under the same circumstance with group A,but difference in scanning condition (scan parameters:100 kV,280 mA).In group C (50 patients),the patients kept one arm rise upward,another arm reach firmly toward the contralateral iliac bone during CT scan(scan parameters:100 kV,250 mA).CT attenuations,noise and SNR values around the soft tissue of thyroid gland,which was in the most severe thyroid artifacts (seventh cervical vertebrae to the first thoracic vertebrae level),were measured among the three groups.Meanwhile,the patient’s dose length product (DLP)and effective dosage (ED)were calculated.The images of the three groups were measured by double-blind method,i.e. severe artifacts,moderate artifacts,mild artifacts,and no artifacts.Results The image quality in group C was significantly higher than that of group A and group B (P＜0.05).There was no difference in subj ective quality between group A and group B (P＞0.05).The CT and noise values of group C were better than those of group A and group B (P＜0.05),while the radiation dosage was lower than that of group A and group B (P＜0.05).Conclusion When the thyroid CT scan is performed with the unilateral limb lifting and the other arm extending to the contralateral iliac bone,the thyroid band artifacts can be effectively reduced and decreasing the kV can reduce the radiation dosage.
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Objective To explore the feasibility of tubular model based segmentation method for cystic artery and three-dimensional (3D) reconstruction model of Calot's triangle.Methods A tubular model based 3D region growing algorithm was proposed for the segmentation of cystic arteries and its adjacent vessels from 13 patients' CT images in DICOM format.The data was transferred to 3D visualization workstation based on a set of CalotShow1.0 software for 3D reconstruction.Results The method could effectively segment cystic artery and obtain the 3D model of Calot's triangle.Conclusions The 3D reconstruction model based on tubular model related vessel segmentation method and CalotShow1.0 can accurately display the spatial positions and adjacent relationships of cystic artery and Calot's triangle.
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Objective To improve the diagnosis of cytomegalovirus pneumonia in patients who have undergone kidney transplantation. Methods The CT appearances of 10 cases were retrospectively analyzed. Results Ground glass opacity was seen in all cases, and disseminated several lobes were seen in 7 cases, diffuse distribution was seen in 3 cases. In addition,lung fibrosis happened in 3 cases,nodule in 2 cases,and consolidation in 3 cases.Conclusion Multi-slice CT could provide very valuable information for early diagnosis of cytomegalovirus pneumonia.
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Objective To evaluate 16-SCT in diagnosing aeute appendicitis.Methods The CT findings of 34 cases were retrospectively analyzed.These cases were all proved acute appendicitis by surgical-pathology.Results 30 cases were confirmed by CT,with accuracy 88% (30/34).The diameter of 28 appendix was more than 6mm;2 collapsed with thickening wall.Periappendiceal fat stranding could be seen in 25 cases.Perforated appendicitis happened in 4 cases.Abscess performed in 2 cases.3 cases were missed,1 misdiagnosed.Conclusion 16-SCT could confirm acute appendicitis and its complication timely and accurately.
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Objective To evaluate the value of 16-slice spiral computed tomography(SCT)in diagnosing acute aortic syndrome.Methods Thirty-four cases with acute aortic syndrome underwent 16-slice SCT,performed with unenhanced,contrast-enhanced scanning of bolus tracking and three-dimensional reconstruction.The CT findings of these cases were analysed.Results Twenty-three of them were confirmed Aortic Dessection(AD),the true and false lumen,intimal flap,extent involved and complications of which were all revealed.Six cases were confirmed intramural aortic hematoma(IMH),with features of ring or crescent-shaped non-enhanced thickening wall around the aorta.Five cases were confirmed penetrating atherosclerotic ulcer(PAU),with features of niche sign outstanding the lumen of the aorta.Conclusion Acute aortic syndrome can he diagnosed exactly and completely by 16-slice SCT,which can provide valuable information to select therapeutic methods.
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Objective To investigate the clinical significance of three-dim en sional CT in diagnosis and treatment of posterior pelvic ring fractures. Methods A retrospective analysis was done for 19 cases of posterior pelvic ring fractur es who were treated from March 2002 to August 2003 and had plain and three-dime nsional CT films. Their radiological characteristics and results were compared b etween the 2 kinds of film. Results 3-D CT corrected the misdiagnosis or uncert ainty of 9 cases who had plain radio-graphs. The 3-D CT showed obvious advanta ges over plain radio-graphs in detecting sacroiliac diastasis, sacroiliac joint fragments, fractures involving iliac and sacral lips abutting the sacroiliac jo int, sacral fracture and complicated comminuted fracture, because it clearly del ineated fractures of posterior pelvic ring and manifested the severity of commin ution and separation. Conclusion The 3-D CT scan provides valuable information for precise diagnosis and treatment plan for the complex posterior pelvic ring f ractures.
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Objective To investigate the value of magnetic resonance (MR) imaging for diagnosing typeⅠ congenital choledochocele and its complications. Methods The MR imaging data of 13 cases with proved typeⅠ congenital choledochocele associated with complications were retrospectively reviewed and compared with operative findings. MR imaging sequences included axial T2W and T1W plain scan, true-FISP coronal images, 2D-MRCP, and Gd-enhanced T1W images. Results All patients had cystic dilatation of the common bile ducts to various degrees. In 6 patients complicated with stone and infection, the bile duct showed uniform wall thickening with marked enhancement, and calculus were depicted within the duct lumen with dilatation of the proximal biliary duct. In 7 cases complicated with carcinoma of biliary duct, a polypoid soft tissue mass or nodule was seen inside the ductal lumen in 3 cases, or the duct wall was irregularly thickened in 4 patients. Six cases received curative operation, but one patient with extensive local infiltration, vascular encasement and lymphadenopathy had only palliative treatment. MR imaging observations were verified by surgery findings in all 13 patients. Conclusion MR imaging is very valuable not only in diagnosing typeⅠ congenital choledochocele, but also in revealing its complications.
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8 years for 4 cases;5~8 years for 8 cases;3~5 years for 3 cases;less than 1 year for 1 case respectively.12 cases were followed up by color-sonography examination.The remaining 6 cases were followed by mail or phonecall.Results All cases reached clinical cure with relief or diasppearance of relevant symptoms and signs after 2~7 days PTA.88.9%(16/18) of the cases regained obility to labour or return to work.2 cases of the patients had lung infarction and heart failure immediately after the treatment,1 patient had recurrent stenosis and thrombosis after 1 year of PTA.Conclusion For treatment of membranous BCS,PTA should be the first choice.The majority methods of preventing recurrent stenosis and thrombosis are antithrombin application before PTA and adequate angioplasty during PTA.