Quantification of the Brain Multiple Sclerosis (MS) Plaque Volume: Comparison of Quantitative and Qualitative Assessments of the Brain MS Plaque Volume in Successive Magnetic Resonance Images before and after Medication Use

Background: Multiple sclerosis (MS) is a demyelinating disease with multiple symptoms. To examine the effect of medications, magnetic resonance imaging (MRI) imaging can be performed. Objectives: This study aimed to compare the visual assessment of MRI images by physicians and the results of a MATLAB-based software developed for evaluating the MS plaque volume. Methods: TYSABRI (natalizumab)-treated patients were enrolled in this study. MRI was performed before and after treatment. A MATLAB-based software was developed to evaluate the MRI images. The images were then subjectively evaluated by three specialists and objectively assessed by the software, and the results were then compared. Results: Thirty-five patients participated in this study. According to the software, the status of 37.14% of the patients improved; however, 62.86% of cases deteriorated after a year of treatment. There was less than 50% agreement between the physicians and less than 55% agreement between the physicians and the software results. A disagreement of almost 45% was observed between the physicians and the software results, as in some cases, small changes were detected in successive images. The second cause of disagreement could be the physicians’ expectations; although the patient’s recovery was highly expected in some cases, their condition deteriorated. Conclusions: The results revealed that the objective assessment of sequential MRI images of MS patients reduced human errors and improved the evaluation of this disease.

Assessing the validity of a cross-platform retinal image segmentation tool in normal and diseased retina

Comparing automated retinal layer segmentation using proprietary software (Heidelberg Spectralis HRA + OCT) and cross-platform Optical Coherence Tomography (OCT) segmentation software (Orion). Image segmentations of normal and diseased (iAMD, DME) eyes were performed using both softwares and then compared to the ‘gold standard’ of manual segmentation. A qualitative assessment and quantitative (layer volume) comparison of segmentations were performed. Segmented images from the two softwares were graded by two masked graders and in cases with difference, a senior retina specialist made a final independent decisive grading. Cross-platform software was significantly better than the proprietary software in the segmentation of NFL and INL layers in Normal eyes. It generated significantly better segmentation only for NFL in iAMD and for INL and OPL layers in DME eyes. In normal eyes, all retinal layer volumes calculated by the two softwares were moderate-strongly correlated except OUTLY. In iAMD eyes, GCIPL, INL, ONL, INLY, TRV layer volumes were moderate-strongly correlated between softwares. In eyes with DME, all layer volume values were moderate-strongly correlated between softwares. Cross-platform software can be used reliably in research settings to study the retinal layers as it compares well against manual segmentation and the commonly used proprietary software for both normal and diseased eyes.

VOLUME COMPARISON OF AUTOMATICALLY RECONSTRUCTED MULTI-LOD BUILDING MODELS FOR URBAN PLANNING APPLICATIONS

3D city models are playing a growing role worldwide as sources of integrated information upon which different urban applications are developed. In the context of urban planning and design, semantic 3D city models can provide plenty of qualitative and quantitative information about the urban context and of the area(s) to be transformed. This paper takes inspiration and continues a work recently published in which several design parameters and Key Performance Indicators are computed from a semantic 3D city model, and later used in a GIS-supported urban design process to develop a new area. As many of such parameters are derived from the gross volume of the building stock, this paper investigates whether and to which extent different building stock models might affect the estimation of the gross volume. The study is carried out in anticipation of the upcoming LoD2-based, country-wide model of the Netherlands that is being finalised by our team. At the same time, the paper investigates whether and which information can be obtained regarding the quality of the LoD2 model from a comparison with the LoD1 one, with a focus on volume calculation.

Volume calibration using a comparison method with a transfer leak flow rate

This paper describes a volume comparison method carried out under a fine/rough vacuum using a small transfer flow rate from a capillary leak artefact. This method is suitable for volumes of vessels with complex shapes such as tubing arrangements equipped with various pneumatic parts (valves, gauges …), sample volumes, etc. The calibration, based on pressure rise measurements performed with a constant-volume flowmeter set-up, exhibits a standard relative uncertainty between 0.03 % and 2 % for volumes ranging from 1 to 3000 cm³, which is only about one order of magnitude higher than capabilities of the gravimetric volume calibration.