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1.
Precise localization of the needle tip during CT-guided percutaneous biopsy is considered to be a key element of a successful procedure. To ensure accuracy, the true needle tip must be differentiated from a false or simulated tip which appears when the CT slice encompasses only the shaft of an angled needle. By obtaining images of an aspiration biopsy needle inserted vertically into a phantom and then incrementally tilting the gantry, the authors were able to compare the characteristic features of the true tip to the simulated tip. The true tip was abrupt and distinct and had an adjacent flame-like low density artifact. The simulated tip was indistinct and tapered, yet still produced the adjacent artifact. We concluded that the shape and distinctness of the end portion of the needle itself, rather than the attendant artifact, were the most reliable criteria for accurate needle tip identification. 相似文献
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目的:比较多层螺旋CT(multi-slice spiral CT,MSCT)与核磁共振血管成像(MRA)、数字减影(DSA)对主动脉夹层(aortic dissection,AD)的诊断价值。方法:对17例AD患者行MSCT检查,并与MRA、DSA的检查结果进行比较。结果:对17例AD患者用MSCT、MRA、DSA都能作出诊断(按DeBakey分型,Ⅰ型有4例,Ⅱ型有1例,Ⅲ型有12例),但只有MSCT能明确显示夹层的范围和分支的受累情况,以及剥离内膜瓣、裂口及主动脉的周围情况。而MRA对裂口的检出率只有21.74%,DSA可达87.0%。结论:MSCT对AD的分型以及破裂口的定位诊断更具准确性,对动脉分支显示更清晰。 相似文献
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Amalia Agut Juana D. Carrillo Agustina Anson Eliseo Belda Marta Soler 《Veterinary radiology & ultrasound》2016,57(3):E30-E33
A young intact female dog was presented with urinary incontinence. Abdominal ultrasound revealed the presence of hyperechoic linear structures within the cranial vagina suggestive of foreign material. A computed tomography (CT) retrograde vaginourethrogram demonstrated the presence of a fistulous tract between the urethra and vagina. A presumptive diagnosis of urethrovaginal fistula due to migration of foreign material was made. The grass awn was removed with vaginoscopic‐guided retrieval. Fourteen days later, surgical repair of the fistula and an ovariohysterectomy were done. This case report emphasizes the usefulness of CT for diagnosis and precise anatomical localization of genitourinary tract fistulas. 相似文献
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Chantelle Franklin Michael Herrtage Karen Harris Marie-Aude Genain 《Veterinary radiology & ultrasound》2023,64(2):194-200
Humeral intracondylar fissures (HIF) have been predominantly reported in spaniel breeds and proposed to be possible risk factors for humeral condyle fractures (HCF). We hypothesized that the prevalence of incidental HIF in French Bulldogs may be greater than that of other brachycephalic breeds. A retrospective, observational, prevalence study was performed using CT examinations of French bulldogs and other brachycephalic breed dogs presenting for an unrelated condition. Two European College of Veterinary Diagnostic and Imaging-certified radiologists reviewed the images of the humeral condyles of these dogs. A classification system was devised to grade the findings. We considered a Score 1 to be normal, Score 2 to have centralised sclerosis, Score 3 to have a partial fissure and Score 4 to have a complete fissure. A total of 228 elbows were reviewed from 122 dogs. Of this population, 145 elbows were from French Bulldogs, 54 were from Pugs, and the remainder were from a mix of other brachycephalic breeds. The prevalence of HIF (score 3 or 4) in elbows of the French bulldog, pug and other breed groups was 6.9% (CI 2.8–11%), 5.6% (CI 0–11.7%), and 3.4% (CI 0–10.15%), respectively. At a dog level, the prevalence of HIF (score 3 or 4 present in at least one elbow) was found to be 11.8% (CI 4.6–19%) in French Bulldogs, 11.1% (CI 0–22.9%) in Pugs, and 5.26% (CI 0–15%) in the other breed group. There was no significant difference between the breed groups. The inter-reviewer reliability for CT scoring of HIF based on Cohen's weighted kappa was low at 0.19. 相似文献
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This paper introduces a method of solving the problem of leather cavity measurement in shoe CAD/CAM by industrial CT technology. Concentrating on peculiarity and requirement of leather cavity measurement, this paper presents a X-ray industrial CT system scheme, which not only satisfy the requirement of leather cavity measurement but also can achieve general industrial CT. measurement. The achievement on data collection system and motion control of stepping motor is emphasized. 相似文献
10.
利用CT扫描技术确定土壤大孔隙分形维数 总被引:16,自引:0,他引:16
土壤大孔隙的大小、形状和分布对水及溶质在土壤中的运移有着深刻影响,由于土壤大孔隙的分布呈现分形规律,根据采用CT扫描法得到的原状土柱各断面图像,采用计盒维数法计算出各断面土壤大孔隙的分形维数。 相似文献