Phase-constrained data extrapolation method for reduction of truncation artifacts

The authors present an improvement to a sigma-filter extrapolation method for the reconstruction of magnetic resonance (MR) images from symmetric discrete Fourier data. By making use of the phase information in the image data, the proposed method can overcome the data inconsistency problem of the original method for handling MR image data with large phase variations, such as those obtained in gradient-echo pulse sequences. Reconstruction results show that its performance is comparable with that of the modified complex sigma-filter method proposed previously to handle the inconsistency problem. However, the new approach has the advantage of reducing computation time by a factor of two with use of a sigma filter applied to real instead of complex images. It is expected that this method will be more practical for use in clinical MR imaging systems.     

天津医科大学第三医院抗生素类药物的利用分析

目的：对抗生素类药物利用状况进行分析，以考察应用情况，促进用药合理性，方法：查阅药库2000年药品购入目录，采用药物利用状况分析法，对抗生素用药频度和药物费用等进行分析。结果：该院应用的抗生素主要为头孢菌素，喹诺酮类；DDDs排序靠前的是诺氟沙星，羟氨苄青霉素和复方新诺明等。结论：该院用药基本合理，但水平较低。     

胃液乳酸定量测定对中晚期胃癌的意义

用比色法测定148例胃癌和非胃癌患者胃液乳酸含量,包括正常对照36例。胃癌患者胃液乳酸含量明显增高,与胃良性疾病及正常人比较,差异非常显著(p<0.001),重叠甚少,有助于初步鉴别胃良性和恶性疾病。     

CT的分叶征表现在肺内孤立结节影像诊断中的价值

目的探讨CT的分叶征表现在肺内孤立结节影像诊断的价值以及CT多平面重组（MPR）对此征检出的意义。方法观察病理证实的周围型小肺癌137例及良性肺内结节45例，将结节的边缘分为4型。对28例肺癌、22例良性结节行MPR，考察其显示分叶征的作用。引入可能性比值（likelihood ratios，LR）以量化良恶性病变在形态学上存在重叠的表现。结果Ⅰ型边缘结节对良性病变的特异性为83．3％（20／24），敏感性为44．4％（20／45）。Ⅳ型边缘结节对周围型小肺癌的特异性为97．6％（83／85），敏感性为60．7％（83／137）。表明Ⅰ型边缘是良性病变的特点；而Ⅳ型边缘是恶性病变的特征。Ⅳ型边缘的结节恶性病变在MPR重组图像上的检出率为64．3％（18／28），与横断面扫描差异有统计学意义（P〈0．01）。结论分叶征对肺内孤立结节的诊断有价值，MPR配合横断面薄层图像有助于提高该征的检出率。     

基于人文理念的护理质量例会实践与体会

建立以人文理念为核心的护理质量分析例会制度，每月召开门诊护士长、护士组长、护士代表例会，分析、讲评门诊护理服务中存在的问题，并提出改进方案，持续改进门诊护理服务质量。     

计算机辅助手术的发展状况和展望——参加第17届国际计算机辅助放射学及手术大会（CARS 03）后记

计算机辅助手术和治疗(IGST)是一个新兴的多学科交叉的研究领域,近年来取得了飞速的发展.作为该领域顶级会议之一的国际计算机辅助放射学及手术大会(CARS2003)于2003年6月25至28日在英国伦敦伊丽莎白二世国际会议中心隆重举行了第17届会议.本文将对这次大会作一回顾和总结,内容包括科学论文方面的评论和产品展览方面的情况.     

Le Fort型骨折的CT表现和分型

目的探讨Le Fort型骨折的CT表现及其分型。方法对62例Le Fort型骨折患者进行薄层螺旋CT扫描和三维重组分析。结果在62例中，Le FortⅠ型10例，Ⅱ型9例，Ⅲ型8例，复合型35例（其中Ⅰ＋Ⅱ型18例，I＋Ⅱ＋Ⅲ型7例，Ⅱ＋Ⅲ型10例）；55例同时伴发颌面部其他骨折。Le Fort型骨折在二维CT上表现为颌面部多发且杂乱的骨折，虽然在发现细小和深部结构的骨折方面优于三维CT成像，但难以作出Le Fort型骨折的诊断；三维CT成像能清晰立体地显示Le Fort型骨折的整体形状及走向，并可明确作出分型。结论三维CT成像是Le Fort型骨折最有效的诊断方法，对临床制定治疗方案具有指导意义，但是对细小骨折诊断不如二维CT。     

审慎诊治脉络膜恶性黑色素瘤

目的 探讨脉络膜恶性黑色素瘤的传统治疗、影像学临床特点及确诊符合率，以指导临床。方法 经临床确诊为脉络膜恶性黑色素瘤患者26例26眼，年龄41～73岁。术前视力0．2至光感。局部及全身检查除外肿瘤原发病灶及转移病灶。结果 26例行眼球摘除术，病理检查结果符合率为88．46％（23／26）。3例3眼病理检查结果为脉络膜出血。结论 审慎诊治脉络膜恶性黑色素瘤，提高确诊率，现代的包括手术在内的治疗方法应加以考虑。     

Vascular Centerline Extraction in 3D MR Angiograms for Phase Contrast MRI Blood Flow Measurement

The accuracy of 2D phase contrast (PC) magnetic resonance angiography (MRA) depends on the alignment between the vessels and the imaging plane. PC MRA imaging of blood flow is challenging when the flow in several vessels is to be evaluated with one acquisition. For this purpose, semi-automatic determination of the plane most perpendicular to several vessels is proposed based on centerlines extracted from 3D MRA. Arterial centerlines are extracted from 3D MRA based on iterative estimation-prediction, multi-scale analysis of image moments, and a second-order shape model. The optimal plane is determined by minimizing misalignment between its normal vector and the centerlines’ tangent vectors. The method was evaluated on a phantom and on 35 patients, by seeking the optimal plane for cerebral blood flow quantification simultaneously in internal carotids and vertebral arteries. In the phantom, difference of orientation and of height between known and calculated planes was 1.2° and 2.5 mm, respectively. In the patients, all but one centerline were correctly extracted and the misalignment of the plane was within 12° per artery. Semi-automatic centerline extraction simplifies and automates determination of the plane orthogonal to one vessel, thereby permitting automatic simultaneous minimization of the misalignment with several vessels in PC MRA.     

Validation of silver-stained nucleolar organizer regions for evaluation of invasive character of urinary bladder carcinoma in rats and mice

A series of 8 rat and 16 mouse invasive bladder carcinomas were investigated for the presence of silverstained nucleolar organizer regions (AgNORs) to clarify whether this parameter is applicable to the estimation of their invasive character. With regard to number of AgNORs per cell, neither rat nor mouse carcinomas showed any difference between invasive and noninvasive sites within the same tumor. However, the frequency of cancer cells bearing bizarre dots, irregular in size and shape, was significantly higher at sites of actual invasion. Quantitative data generated using an image analyzer revealed significantly lower values for NOR roundness and significantly larger NOR size in invasive sites than in noninvasive sites in all groups. Double staining for the proliferation marker proliferating cell nuclear antigen (PCNA) and AgNORs was performed on eight rat carcinomas and a close correlation between the two was confirmed. Thus the number of AgNORs in PCNA-positive cells was significantly greater than in PCNA-negative cells. Furthermore, a particularly strong correlation was observed for incidences of PCNA-positive cells and bizarre dots (P<0.01). The quantitative data also demonstrated significant differences in size and shape of dots. It is concluded that AgNORs have diagnostic value for the invasive character of bladder carcinomas.