Viewdex: A Status Report

Svalkvist, Angelica; Svensson, Sophie; Håkansson, Markus; Båth, Magnus; Månsson, Lars Gunnar

doi:10.1093/rpd/ncv543

Cited by 46 publications

(20 citation statements)

References 28 publications

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“…The radiologists were informed that participants underwent nodule surveillance, but they were blinded to clinical information and number of nodules. The anonymized DTS images were displayed in a randomized order in both studies on a high-resolution medicalgrade flat-panel in the ViewDEX, an in-house-developed freeware software for conducting observer performance studies (28)(29)(30), in a room with low ambient light. The readers were familiar with the software and type of study and had access to adjustment of window settings and tools for measurements and enlarging.…”

Section: Discussionmentioning

confidence: 99%

Detection and Characterization of Solid Pulmonary Nodules at Digital Chest Tomosynthesis: Data from a Cohort of the Pilot Swedish Cardiopulmonary Bioimage Study

Meltzer¹,

Vikgren²,

Bergman³

et al. 2018

Radiology

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Purpose To investigate the performance of digital tomosynthesis (DTS) for detection and characterization of incidental solid lung nodules. Materials and Methods This prospective study was based on a population study with 1111 randomly selected participants (age range, 50-64 years) who underwent a medical evaluation that included chest computed tomography (CT). Among these, 125 participants with incidental nodules 5 mm or larger were included in this study, which added DTS in conjunction with the follow-up CT and was performed between March 2012 and October 2014. DTS images were assessed by four thoracic radiologists blinded to the true number of nodules in two separate sessions according to the 5-mm (125 participants) and 6-mm (55 participants) cut-off for follow-up of incidental nodules. Pulmonary nodules were directly marked on the images by the readers and graded regarding confidence of presence and recommendation for follow-up. Statistical analyses included jackknife free-response receiver operating characteristic, receiver operating characteristic, and Cohen κ coefficient. Results Overall detection rate ranges of CT-proven nodules 5 mm or larger and 6 mm or larger were, respectively, 49%-58% and 48%-62%. Jackknife free-response receiver operating characteristics figure of merit for detection of CT-proven nodules 5 mm or larger and 6 mm or larger was 0.47 and 0.51, respectively, and area under the receiver operating characteristic curve regarding recommendation for follow-up was 0.62 and 0.65, respectively. Conclusion Routine use of DTS would result in lower detection rates and reduced number of small nodules recommended for follow-up. RSNA, 2018.

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Section: Discussionmentioning

confidence: 99%

Detection and Characterization of Solid Pulmonary Nodules at Digital Chest Tomosynthesis: Data from a Cohort of the Pilot Swedish Cardiopulmonary Bioimage Study

Meltzer¹,

Vikgren²,

Bergman³

et al. 2018

Radiology

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“…Regardless of the choice of evaluation method in an optimisation process, an effective image viewer with integrated recording of the ratings is desirable. ViewDEX (Viewer for Digital Evaluation of X-ray images) (120)(121)(122) is free-ware especially developed for this purpose. Both the viewing properties and registration properties of the ratings can be edited by the user, and the system can be adapted for both ROC and visual grading studies.…”

Section: Discussionmentioning

confidence: 99%

The Validity of Using Roc Software for Analysing Visual Grading Characteristics Data: An Investigation Based on the Novel Software VGC Analyzer

Hansson

Månsson

Båth

2016

Radiat Prot Dosimetry

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The purpose of the present work was to investigate the validity of using single-reader-adapted receiver operating characteristics (ROC) software for analysis of visual grading characteristics (VGC) data. VGC data from four published VGC studies on optimisation of X-ray examinations, previously analysed using ROCFIT, were reanalysed using a recently developed software dedicated to VGC analysis (VGC Analyzer), and the outcomes [the mean and 95 % confidence interval (CI) of the area under the VGC curve (AUCVGC) and the p-value] were compared. The studies included both paired and non-paired data and were reanalysed both for the fixed-reader and the random-reader situations. The results showed good agreement between the softwares for the mean AUCVGC For non-paired data, wider CIs were obtained with VGC Analyzer than previously reported, whereas for paired data, the previously reported CIs were similar or even broader. Similar observations were made for the p-values. The results indicate that the use of single-reader-adapted ROC software such as ROCFIT for analysing non-paired VGC data may lead to an increased risk of committing Type I errors, especially in the random-reader situation. On the other hand, the use of ROC software for analysis of paired VGC data may lead to an increased risk of committing Type II errors, especially in the fixed-reader situation.

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“…Their task was to determine the longest diameter of all the simulated nodules at all three dose levels. The images were displayed using ViewDEX ( 34 – 36 ) , a software designed for use in observer studies with medical images and which includes a tool for performing manual size measurements in the images. For adjustment of the image size during the viewing, a bicubic pixel value interpolation algorithm was used.…”

Section: Methodsmentioning

confidence: 99%

Effect of Radiation Dose Level on Accuracy and Precision of Manual Size Measurements in Chest Tomosynthesis Evaluated Using Simulated Pulmonary Nodules

Söderman

Johnsson

Vikgren

et al. 2016

Radiat Prot Dosimetry

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The aim of the present study was to investigate the dependency of the accuracy and precision of nodule diameter measurements on the radiation dose level in chest tomosynthesis. Artificial ellipsoid-shaped nodules with known dimensions were inserted in clinical chest tomosynthesis images. Noise was added to the images in order to simulate radiation dose levels corresponding to effective doses for a standard-sized patient of 0.06 and 0.04 mSv. These levels were compared with the original dose level, corresponding to an effective dose of 0.12 mSv for a standard-sized patient. Four thoracic radiologists measured the longest diameter of the nodules. The study was restricted to nodules located in high-dose areas of the tomosynthesis projection radiographs. A significant decrease of the measurement accuracy and intraobserver variability was seen for the lowest dose level for a subset of the observers. No significant effect of dose level on the interobserver variability was found. The number of non-measurable small nodules (≤5 mm) was higher for the two lowest dose levels compared with the original dose level. In conclusion, for pulmonary nodules at positions in the lung corresponding to locations in high-dose areas of the projection radiographs, using a radiation dose level resulting in an effective dose of 0.06 mSv to a standard-sized patient may be possible in chest tomosynthesis without affecting the accuracy and precision of nodule diameter measurements to any large extent. However, an increasing number of non-measurable small nodules (≤5 mm) with decreasing radiation dose may raise some concerns regarding an applied general dose reduction for chest tomosynthesis examinations in the clinical praxis.

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Viewdex: A Status Report

Cited by 46 publications

References 28 publications

Detection and Characterization of Solid Pulmonary Nodules at Digital Chest Tomosynthesis: Data from a Cohort of the Pilot Swedish Cardiopulmonary Bioimage Study

Detection and Characterization of Solid Pulmonary Nodules at Digital Chest Tomosynthesis: Data from a Cohort of the Pilot Swedish Cardiopulmonary Bioimage Study

The Validity of Using Roc Software for Analysing Visual Grading Characteristics Data: An Investigation Based on the Novel Software VGC Analyzer

Effect of Radiation Dose Level on Accuracy and Precision of Manual Size Measurements in Chest Tomosynthesis Evaluated Using Simulated Pulmonary Nodules

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