Influence of lung nodule margin on volume- and diameter-based reader variability in CT lung cancer screening.

OBJECTIVE:: To evaluate the influence of nodule margin on inter- and intrareader variability in manual diameter measurements and semi-automatic volume measurements of solid nodules detected in low-dose CT lung cancer screening. METHODS:: 25 nodules of each morphological category (smooth, lobulated, spiculated and irregular) were randomly selected from 93 participants of the Dutch-Belgian Randomized Lung Cancer Screening Trial (NELSON). Semi-automatic volume measurements were performed using Syngo LungCARE® software (Version Somaris/5 VB10A-W, Siemens, Forchheim, Germany). Three radiologists independently measured mean diameters manually. Impact of nodule margin on interreader variability was evaluated based on systematic error and 95% limits of agreement. Interreader variability was compared with the nodule growth cut-off as used in Lung CT Screening Reporting and Data System (LungRADS; +1.5-mm diameter) and the Dutch-Belgian Randomized Lung Cancer Screening Trial(acronym: NELSON) /British Thoracic Society (+25% volume). RESULTS:: For manual diameter measurements, a significant systematic error (up to 1.2 mm) between readers was found in all morphological categories. For semi-automatic volume measurements, no statistically significant systematic error was found. The interreader variability in mean diameter measurements exceeded the 1.5-mm cut-off for nodule growth for all morphological categories [smooth: ±1.9 mm (+27%), lobulated: ±2.0 mm (+33%), spiculated: ±3.5 mm (+133%), irregular: ±4.5 mm (+200%)]. The 25% vol growth cut-off was exceeded slightly for spiculated [28% (+12%)] and irregular [27% (+8%)] nodules. CONCLUSION:: Lung nodule sizing based on manual diameter measurement is affected by nodule margin. Interreader variability increases especially for nodules with spiculated and irregular margins, and causes substantial misclassification of nodule growth. This effect is almost neglectable for semi-automated volume measurements. Semi-automatic volume measurements are superior for both size and growth determination of pulmonary nodules. ADVANCES IN KNOWLEDGE:: Nodule assessment based on manual diameter measurements is susceptible to nodule margin. This effect is almost neglectable for semi-automated volume measurements. The larger interreader variability for manual diameter measurement results in inaccurate lung nodule growth detection and size classification.

Informatics in radiology: postprocessing pitfalls in using CT for automatic and semiautomatic determination of global left ventricular function.

Recent advances in technical capabilities of computed tomographic (CT) scanners, including an increasing number of detector rows, improved spatial and temporal resolution, and the development of retrospective gating, have allowed the acquisition of four-dimensional (4D) datasets of the beating heart. As a result, the heart can be visualized in different phases and CT datasets can be used to assess cardiac function. Many software packages currently exist that allow automatic or semiautomatic evaluation of left ventricular function on the basis of 4D CT datasets. The level of automation varies from extensive, completely manual segmentation by the user to fully automatic evaluation of left ventricular function without any user interaction. Although the reproducibility of functional parameter assessment is reported to be high and intersoftware variability low for larger groups of patients, significant differences can exist among measurements obtained with different software tools from the same dataset. Thus, careful review of automatically or semiautomatically obtained results is required.

Accuracy of noninvasive coronary stenosis quantification of different commercially available dedicated software packages.

PURPOSE: The purpose of this study was to investigate the noninvasive quantification of coronary artery stenosis using cardiac software packages and vessel phantoms with known stenosis severity. MATERIALS AND METHODS: Four different sizes of vessel phantoms were filled with contrast agent and scanned on a 64-slice multidetector computed tomography. Diameter and area stenosis were evaluated by 2 observers blinded from the true measures using 5 different software packages. Measurements were compared with the true measure of the vessel phantoms. The absolute difference in stenosis measurements and intraobserver and interobserver variabilities were assessed. RESULTS: All software packages show a trend toward larger differences for the smaller vessel phantoms. The absolute difference of the automatic measurements was significantly higher compared with that of the manual measurements in all 5 evaluated software packages for all vessel phantoms (P < 0.05). CONCLUSION: Manual stenosis measurements are significantly more accurate compared with automatic measurements, and therefore, manual adjustments are still essential for noninvasive assessment of coronary artery stenosis.

Evaluation of global left ventricular function assessment by dual-source computed tomography compared with MRI.

Left ventricular (LV) function assessment by dual-source computed tomography (DSCT) was compared with the reference standard method using magnetic resonance imaging (MRI). Accurate assessment of LV function is essential for the prediction of prognosis in cardiac disease. Thirty-four patients undergoing DSCT examination of the heart for various clinical indications underwent MRI after DSCT. Short-axis cine images were reconstructed from the DSCT datasets and were analyzed using a dedicated post-processing software-tool to generate global left ventricular function parameters. Five DSCT datasets were considered to be of insufficient image quality. DSCT showed a small overestimation of end-diastolic and end-systolic volumes of 11.0 ml and 3.5 ml, respectively. Myocardial mass assessed by DSCT showed an average underestimation of 0.2 g. DSCT showed a small overestimation of LV ejection fraction (LVEF) of 0.4%-point with a Bland-Altman interval of [-8.67 (0.40) 9.48]. Global LV functional parameters calculated from DSCT datasets acquired in daily clinical practice correlated well with MRI and may be considered interchangeable. However, visual assessment of the image quality of the short-axis cine slices should be performed to detect any artifacts in the DSCT data which could influence accuracy.

Dedicated education units: 2. An evaluation.

This paper reports on an evaluation of a new concept in clinical nurse education: the Dedicated Education Unit (DEU). Developed by the School of Nursing, The Flinders University of South Australia, the DEU aims to optimise undergraduate student learning through enhancement of the clinical learning environment and collaboration between clinicians, academics and students. Three DEUs involving 91 students were evaluated, using primarily summative methods to elicit positive and negative attributes of the DEUs. Outcomes indicated that the DEU is a highly appropriate clinical placement model. (Part one of this paper explained the rationale for the DEU and its key features.)

Dedicated education units: 1. A new concept for clinical teaching and learning.

The Dedicated Education Unit (DEU) is a new concept in clinical nurse education. The DEU plays a major role in enhancing links between health care providers and The Flinders University of South Australia (FUSA) School of Nursing. This collaborative venture has created a more positive clinical learning environment, maximized the achievement of student learning outcomes, and nurtured closer partnership between clinicians and academics. Recognition of mutuality, respect and trust among all stakeholders is central to its success. This paper (part one) explains the rationale for the DEU and describes its inherent values. Part two reports on an evaluation of the DEU.

[Blaschkolinear eruption with biological signs of lupus]. / Eruption blaschko-linéaire avec biologie lupique.

INTRODUCTION: Acquired inflammatory dermatoses of the adult with a blaschkolinear arrangement are rare. Their cause is unknown. CASE REPORT: We report the case of a 35-year-old man who presented an unilateral skin eruption covering the forearm and with secondary blaschkolinear extension to the arm, the axillary region and the chest. In this particular case, the patient was positive for RNP type anti-nuclear antibodies and direct immunofluorescence was positive in both biopsies of the lesions and of healthy skin. The eruption lasted 6 months and regressed spontaneously. DISCUSSION: Such cases are exceptional and the nosology is difficult to establish. A particular form of lupus erythematosus? Fortuitous coexpression of lupus antibodies and blaschkitis in an adult?

Stimulation of diploid fibroblast growth with serum-free medium conditioned by mezerein-treated monocytic leukemia cells.

Medium conditioned by mezerein-treated human acute monocytic leukemia cells (THP-1) stimulated human fibroblast replication. Maximum mitogenic activity was elaborated by THP-1 cells with a 24-hr incubation in 10(-7) M mezerein (activator phase) followed by a 36-hr incubation in insulin-supplemented serum-free Roswell Park Memorial Institute (RPMI)-1640 medium (effector phase). Growth stimulation was not due to the presence of residual mezerein. We previously reported that leukemia cells also produced a growth inhibitor. Fibroblast stimulation was resolved by isoelectrofocusing into several active fractions separate from the growth inhibitory activity for malignant mammary cells. Conditioned medium was mitogenic for fibroblasts in the presence of high concentrations of fetal bovine and human whole blood sera. Growth stimulation was observed in plasma-derived serum only when supplemented with exogenous platelet-derived growth factor. Thus, this THP-1 cell product does not fulfill the role of a competence factor.

Cognitive strategy training and intellectual performance in the elderly.

Reduced intellectual performance in the elderly was conceptualized as an experientail deficit than can be reversed by training relevant component skills. Sixty female elderly subjects (ages 63 to 95) participated in three phases of the experiment: Training, Immediate Posttest, and Delayed Posttest. Training was geared at strengthening covert self-monitoring strategies in complex reasoning problems, and training effects were evaluated both on the training and a transfer task. Results showed raised performance in the training conditions, transfer effects, and maintenance of training and transfer effects over 2 weeks. Implications for theories of adult intelligence are discussed.