Differentiation of benign and malignant vertebral fractures using a convolutional neural network to extract CT-based texture features.

PURPOSE To assess the diagnostic performance of three-dimensional (3D) CT-based texture features (TFs) using a convolutional neural network (CNN)-based framework to differentiate benign (osteoporotic) and malignant vertebral fractures (VFs). METHODS A total of 409 patients who underwent routine thoracolumbar spine CT at two institutions were included. VFs were categorized as benign or malignant using either biopsy or imaging follow-up of at least three months as standard of reference. Automated detection, labelling, and segmentation of the vertebrae were performed using a CNN-based framework ( https://anduin.bonescreen.de ). Eight TFs were extracted: Varianceglobal, Skewnessglobal, energy, entropy, short-run emphasis (SRE), long-run emphasis (LRE), run-length non-uniformity (RLN), and run percentage (RP). Multivariate regression models adjusted for age and sex were used to compare TFs between benign and malignant VFs. RESULTS Skewnessglobal showed a significant difference between the two groups when analyzing fractured vertebrae from T1 to L6 (benign fracture group: 0.70 [0.64-0.76]; malignant fracture group: 0.59 [0.56-0.63]; and p = 0.017), suggesting a higher skewness in benign VFs compared to malignant VFs. CONCLUSION Three-dimensional CT-based global TF skewness assessed using a CNN-based framework showed significant difference between benign and malignant thoracolumbar VFs and may therefore contribute to the clinical diagnostic work-up of patients with VFs

Is Weight Loss Associated with Less Progression of Changes in Knee Articular Cartilage among Obese and Overweight Patients as Assessed with MR Imaging over 48 Months? Data from the Osteoarthritis Initiative

Purpose To investigate the association of weight loss with progression of cartilage changes at magnetic resonance (MR) imaging over 48 months in overweight and obese participants compared with participants of stable weight. Materials and Methods The institutional review boards of the four participating centers approved this HIPAA-compliant study. Included were (a) 640 participants (mean age, 62.9 years ± 9.1 [standard deviation]; 398 women) who were overweight or obese (body mass index cutpoints of 25 and 30 kg/m2, respectively) from the Osteoarthritis Initiative, with risk factors for osteoarthritis or mild to moderate radiographic findings of osteoarthritis, categorized into groups with (a) weight loss of more than 10% (n = 82), (b) weight loss of 5%-10% (n = 238), or (c) stable weight (n = 320) over 48 months. Participants were frequency-matched for age, sex, baseline body mass index, and Kellgren-Lawrence score. Two radiologists assessed cartilage and meniscus defects on right knee 3-T MR images at baseline and 48 months by using the modified Whole-Organ Magnetic Resonance Imaging Score (WORMS). Progression of the subscores was compared between the weight loss groups by using multivariable logistic regression models. Results Over 48 months, adjusted mean increase of cartilage WORMS was significantly smaller in the 5%-10% weight loss group (1.6; 95% confidence interval [CI]: 1.3, 1.9; P = .002) and even smaller in the group with more than 10% weight loss (1.0; 95% CI: 0.6, 1.4; P = .001) when compared with the stable weight group (2.3; 95% CI: 2.0, 2.7). Moreover, percentage of weight change was significantly associated with increase in cartilage WORMS (β = 0.2; 95% CI: 0.02, 0.4; P = .007). Conclusion Participants who lost weight over 48 months showed significantly lower cartilage degeneration, as assessed with MR imaging; rates of progression were lower with greater weight loss. © RSNA, 2017

Dark-field X-ray imaging for the assessment of osteoporosis in human lumbar spine specimens

Background: Dark-field imaging is a novel imaging modality that allows for the assessment of material interfaces by exploiting the wave character of x-ray. While it has been extensively studied in chest imaging, only little is known about the modality for imaging other tissues. Therefore, the purpose of this study was to evaluate whether a clinical X-ray dark-field scanner prototype allows for the assessment of osteoporosis.Materials and methods: In this prospective study we examined human cadaveric lumbar spine specimens (vertebral segments L2 to L4). We used a clinical prototype for dark-field radiography that yields both attenuation and dark-field images. All specimens were scanned in lateral orientation in vertical and horizontal position. All specimens were additionally imaged with CT as reference. Bone mineral density (BMD) values were derived from asynchronously calibrated quantitative CT measurements. Correlations between attenuation signal, dark-field signal and BMD were assessed using Spearman’s rank correlation coefficients. The capability of the dark-field signal for the detection of osteoporosis/osteopenia was evaluated with receiver operating characteristics (ROC) curve analysis.Results: A total of 58 vertebrae from 20 human cadaveric spine specimens (mean age, 73 years ±13 [standard deviation]; 11 women) were studied. The dark-field signal was positively correlated with the BMD, both in vertical (r = 0.56, p < .001) and horizontal position (r = 0.43, p < .001). Also, the dark-field signal ratio was positively correlated with BMD (r = 0.30, p = .02). No correlation was found between the signal ratio of attenuation signal and BMD (r = 0.14, p = .29). For the differentiation between specimens with and without osteoporosis/osteopenia, the area under the ROC curve (AUC) was 0.80 for the dark-field signal in vertical position.Conclusion: Dark-field imaging allows for the differentiation between spine specimens with and without osteoporosis/osteopenia and may therefore be a potential biomarker for bone stability

Imaging of Osteoarthritis in Geriatric Patients.

Imaging of osteoarthritis (OA) in the elderly is gaining importance because of the aging population. It requires knowledge about findings relevant for patient management and others which are abnormal findings, but part of normal aging without relevance for patient management due to lack of clinical symptoms. This review will provide information on what imaging techniques are best used for knee OA and how to systematically assess knee joint structures in order to cover the most common asymptomatic and symptomatic MR findings in OA. We will discuss which findings are typically found in older patients and which are likely to progress to severe pain and disability, finally leading to total joint replacement. The review may aid radiologists and referring clinicians to better understand the evolution of symptomatic OA and the current or future clinical significance of the most common symptomatic and asymptomatic findings

Natural evolution of popliteomeniscal fascicle tears over 2 years and its association with lateral articular knee cartilage degeneration in patients with traumatic anterior cruciate ligament tear.

ObjectivesTo assess (i) normal imaging anatomy of the popliteomeniscal fascicles, (ii) prevalence and natural evolution of popliteomeniscal fascicle tears (PMFT) in subjects with traumatic anterior cruciate ligament (ACL) tears over 2 years and (iii) compare knee cartilage degeneration in subjects with and without PMFT longitudinally.Methods57 subjects with ACL tears were screened for PMFT. Morphological (high-resolution 3D fast spin-echo) and compositional (T1ρ and T2 mapping) MR imaging was performed prior to and 2 years after ACL reconstruction. Differences of morphological and compositional parameters were compared between subjects with and without PMFT using logistic regression, adjusting for age, sex and BMI.ResultsIn 24% (n = 14) of the subjects with ACL tear a PMFT was detected on baseline MRI. One subject with PMFT developed a meniscal tear over 2 years. Cartilage ∆T1ρ of the lateral femur increased significantly more in subjects with isolated PMFT compared to controls (mean difference, 2.0 ± 2.9 vs. -1.3 ± 1.6, p = 0.027).ConclusionPMFT detected by MRI are a common finding in subjects with ACL tears. Subjects with these defects showed higher compositional cartilage deterioration compared to controls, over 2 years in the lateral femoral compartment, indicating accelerated cartilage degeneration.Key points• Popliteomeniscal fascicle lesions are a common finding in subjects with ACL tears. • Progression to a meniscal tear over 2 years is not frequent. • Anteroinferior popliteomeniscal fascicle is injured most frequently. • Patients with popliteomeniscal fascicle lesions showed accelerated cartilage degeneration