Operator-independent quantitative chest computed tomography versus standard assessment of interstitial lung disease related to systemic sclerosis: A multi-centric study

Abstract

Purpose. Interstitial lung disease (ILD) related to systemic sclerosis (SSc) is assessed with pulmonary functional tests (PFTs) and semi-quantitative scores based on extent of ILD detectable on chest computed tomography (CT). CT quantitative indexes (QCTIs) are promising tools to assess extent of ILD. This study's aim is to evaluate the validity of QCTI compared with that of chest CT standard evaluation and PFTs. Moreover, QCTI differences between patients’ subgroups according to prognostic stratifications were investigated.

Methods. ILD-SSc of patients from six rheumatological clinics was routinely assessed with chest CT and PFTs. Patients were clustered according to prognosis based on functional and/or radiological examinations. Finally, chest CTs were processed with OsiriX in order to obtain QCTI.

Results. Two hundred fifty-seven SSc patients were enrolled. QCTI correlation between extent of ILD and PFTs range from ? 0.60 to 0.58 and from ? 0.54 to 0.52, respectively. The majority of QCTI have a different distribution in patients’ subgroups based on prognosis. Most of QCTI discriminate patients with an ILD severity leading to a poor prognosis.

Conclusions. QCTI assessment of ILD-SSc is comparable to the evaluation based on chest CT and/or PFTs. QCTI values corresponding to severe ILD were identified. QCTIs are excellent candidates for a new and more reliable SSc-ILD assessment.     

Accuracy and Reliability of Length Measurements on Three-Dimensional Computed Tomography Using Open-Source OsiriX Software

There is a growing interest in three-dimensional computed tomography (3D-CT) as a research tool for the study of bone, joint anatomy, and kinematics. However, when CT data are processed and handled manually using image processing programs to yield 3D image and coordinate value, systematic and random errors should be validated. We evaluated the accuracy and reliability of length measurement on CT with OsiriX software. 3D-CT scans were made of 14 frozen pig knees with five transosseous holes in the metaphyseal portion of femur. The lengths between tunnel orifices were measured using Mitutoyo Digimatic digital calipers to establish the gold standard, and with the OsiriX program in 3D multi-planar reformatting mode for comparison. All measurements were recorded by a principal (replicate 1, trial 1) and a secondary observer (replicate 2, trial 1) and were repeated once by each observer (trial 2). The mean differences between OsiriX and real measurements were less than 0.1 mm in both replicates, and maximum differences were less than 0.3 mm. There were no significant differences between the replicates and real measurements (p=0.544 and 0.622 for replicates 1 and 2, respectively). The intraclass correlation coefficients (ICC) were very high between trials and between replicates (ICC=0.998 and 0.999, respectively). For kinematic analysis of the knees, length measurements on 3D-CT using OsiriX program can be used as alternatives to real measurements with less than 0.3-mm accuracy and very high reliability.     

Osirix图像处理软件在老年髋部骨折快速诊断与手术决策中的应用初探

[目的]以外科医生对影像学检查特有的要求,采用OsiriX图像处理软件对急诊CT检查结果DICOM图像实现3D重建和处理,以期对老年髋部骨折实现快速、客观、全面的描述以利手术决策.[方法]调阅2010年1月～10月期间143例因髋部骨折而住院的老年患者的急诊CT检查结果.采用OsiriX软件的2D图像查看器、图像3D处理器、图像优化等功能,对上述急诊CT的DICOM图像进行3D处理、判读结果,并与急诊CT报告对照以验证准确性.[结果]所有患者急诊CT检查DICOM图像均可实现2D查看和3D处理.143例患者中,发现急诊CT检查报告中未提及但不影响手术决策的髋部骨裂1例.[结论]OsiriX在老年髋部骨折的快速、全面、客观、准确的诊断和于.术决策方面具有实用性和指导意义.能够实现从外科手术和治疗的要求出发,审阅并处理影像学检查的结果.其在其他骨科创伤中的应用尚需进一步实践和研究.     

3.0T MR半自动软件软骨体积定量测量的可重复性及准确性

目的 评估在3.0T MR上使用半自动软件OsiriX测量膝关节软骨体积的可重复性及准确性. 方法 在3.0T MR上使用MR轴位水激发3D-FLASH序列对30名健康受试者的右膝关节进行重复扫描.全部图像由3名观察者分别使用开放源软件OsiriX进行软骨的半自动分割及随机工作站进行人工分割,计算软骨体积,比较两种方法测量软骨体积所需时间、可重复性及测量结果. 结果 ①OsiriX软件分割比人工分割节省50%以上时间;②OsiriX软件分割及人工分割的观察者间可重复性误差分别为4.88%和9.82%,高年资观察者内部可重复性误差分别为0.77%和1.29%,个体内部可重复性误差范围分别为0.14%～1.11%和0.52%～1.61%.前者各项可重复性误差均低于后者(P＜0.05);③OsiriX软件分割的系统误差为(-3.80±3.93)%,随机配对误差为(4.68±2.70)%,差异无统计学意义(t=0.92,P=0.36). 结论 与人工分割相比,OsiriX半自动分割测量软骨体积具有省时、观察者间及观察者内可重复性高、有相对固定标准等明显优势,可用于临床及多中心大样本量研究.