X-ray-based quantitative osteoporosis imaging at the spine.

Osteoporosis is a metabolic bone disease with a high prevalence that affects the population worldwide, particularly the elderly. It is often due to fractures associated with bone fragility that the diagnosis of osteoporosis becomes clinically evident. However, early diagnosis would be necessary to initiate therapy and to prevent occurrence of further fractures, thus reducing morbidity and mortality. X-ray-based imaging plays a key role for fracture risk assessment and monitoring of osteoporosis. Whereas over decades dual-energy X-ray absorptiometry (DXA) has been the main method used and still reflects the reference standard, another modality reemerges with quantitative computed tomography (QCT) because of its three-dimensional advantages and the opportunistic exploitation of routine CT scans. Against this background, this article intends to review and evaluate recent advances in the field of X-ray-based quantitative imaging of osteoporosis at the spine. First, standard DXA with the recent addition of trabecular bone score (TBS) is presented. Secondly, standard QCT, dual-energy BMD quantification, and opportunistic BMD screening in non-dedicated CT exams are discussed. Lastly, finite element analysis and microstructural parameter analysis are reviewed.

Correction to: Analysis and quantification of bone healing after open wedge high tibial osteotomy.

Correction to: Wien Klin Wochenschr 2019 https://doi.org/10.1007/s00508-019-01541-8The original version of this article unfortunately contained a mistake. The presentation of Tab. 4 was incorrect. The corrected table is given below.The original article has been ….

Opportunistic osteoporosis screening in multi-detector CT images via local classification of textures.

Our study proposed an automatic pipeline for opportunistic osteoporosis screening using 3D texture features and regional vBMD using multi-detector CT images. A combination of different local and global texture features outperformed the global vBMD and showed high discriminative power to identify patients with vertebral fractures. INTRODUCTION: Many patients at risk for osteoporosis undergo computed tomography (CT) scans, usable for opportunistic (non-dedicated) screening. We compared the performance of global volumetric bone mineral density (vBMD) with a random forest classifier based on regional vBMD and 3D texture features to separate patients with and without osteoporotic fractures. METHODS: In total, 154 patients (mean age 64 ± 8.5, male; n = 103) were included in this retrospective single-center analysis, who underwent contrast-enhanced CT for other reasons than osteoporosis screening. Patients were dichotomized regarding prevalent vertebral osteoporotic fractures (noFX, n = 101; FX, n = 53). Vertebral bodies were automatically segmented, and trabecular vBMD was calculated with a dedicated phantom. For 3D texture analysis, we extracted gray-level co-occurrence matrix Haralick features (HAR), histogram of gradients (HoG), local binary patterns (LBP), and wavelets (WL). Fractured vertebrae were excluded for texture-feature and vBMD data extraction. The performance to identify patients with prevalent osteoporotic vertebral fractures was evaluated in a fourfold cross-validation. RESULTS: The random forest classifier showed a high discriminatory power (AUC = 0.88). Parameters of all vertebral levels significantly contributed to this classification. Importantly, the AUC of the proposed algorithm was significantly higher than that of volumetric global BMD alone (AUC = 0.64). CONCLUSION: The presented classifier combining 3D texture features and regional vBMD including the complete thoracolumbar spine showed high discriminatory power to identify patients with vertebral fractures and had a better diagnostic performance than vBMD alone.

[Measurement instead of scoring in rheumatology: new quantitative imaging and processing methods in radiology]. / Messen statt scoren in der Rheumatologie : Neue quantitative Bildgebungs- und -verarbeitungsmethoden der Radiologie.

Many radiological methods to statistically evaluate progression of rheumatic diseases have been presented in recent years. This review article explains their basics as well as the background to the development of "imaging biomarkers" and their potential application in rheumatology.

[Computer assisted radiological diagnostics of arthritic joint alterations]. / Computerassistierte radiologische Diagnostik arthritischer Gelenkveränderungen.

Computer assisted diagnosis (CAD) schemes are currently used in the field of musculoskeletal diseases to quantitatively assess vertebral fractures, joint space narrowing, andr erosion. Most systems work semi-automatically, i.e. they are operator dependent in the selection of anatomical landmarks. Fully automatic programs are currently under development. Some CAD products have already been successfully used in clinical trials.

[Quantitative imaging in rheumatoid arthritis: from scoring to measurement]. / Quantitative Bildgebung bei rheumatoider Arthritis: Vom Scoring zur Messung.

The need of clinical sciences to measure therapy effects on chronic illness led to development, evaluation, and publication of several radiological methods to monitor disease progression of rheumatic diseases. This review article explains the basics and background of scoring and measurement. The radiologist thus learns to report more compactly and to communicate the results more specifically.