Fractal lacunarity of trabecular bone and magnetic resonance imaging: New perspectives for osteoporotic fracture risk assessment

Abstract

Osteoporosis represents one major health condition for our growing elderly population. It accounts for severe morbidity and increased mortality in postmenopausal women and it is becoming an emerging health concern even in aging men. Screening of the population at risk for bone degeneration and treatment assessment of osteoporotic patients to prevent bone fragility fractures represent useful tools to improve quality of life in the elderly and to lighten the related socio-economic impact. Bone mineral density (BMD) estimate by means of dualenergy X-ray absorptiometry is normally used in clinical practice for osteoporosis diagnosis. Nevertheless, BMD alone does not represent a good predictor of fracture risk. From a clinical point of view, bone microarchitecture seems to be an intriguing aspect to characterize bone alteration patterns in aging and pathology. The widening into clinical practice of medical imaging techniques and the impressive advances in information technologies together with enhanced capacity of power calculation have promoted proliferation of new methods to assess changes of trabecular bone architecture (TBA) during aging and osteoporosis. Magnetic resonance imaging (MRI) has recently arisen as a useful tool to measure bone structure in vivo . In particular, high-resolution MRI techniques have introduced new perspectives for TBA characterization by non-invasive non-ionizing methods. However, texture analysis methods have not found favor with clinicians as they produce quite a few parameters whose interpretation is difficult. The introduction in biomedical field of paradigms, such as theory of complexity, chaos, and fractals, suggests new approaches and provides innovative tools to develop computerized methods that, by producing a limited number of parameters sensitive to pathology onset and progression, would speed up their application into clinical practice. Complexity of living beings and fractality of several physio-anatomic structures suggest fractal analysis as a promising approach to quantify morphofunctional changes in both aging and pathology. In this particular context, fractal lacunarity seems to be the proper tool to characterize TBA texture as it is able to describe both discontinuity of bone network and sizes of bone marrow spaces, whose changes are an index of bone fracture risk. In this paper, an original method of MRI texture analysis, based on TBA fractal lacunarity is described and discussed in the light of new perspectives for early diagnosis of osteoporotic fractures.

Biocomplexity and Fractality in the Search of Biomarkers of Aging and Pathology: Mitochondrial DNA Profiling of Parkinson’s Disease

“…In this study we confirm that fractal analysis represents a useful tool to discriminate between aging and age-related pathologies [33,63,65]. In particular, fractal lacunarity analysis of mtDNA, performed by our method, is able to highlight a statistically significant difference of mtDNA mutation profile between PD patients and age-matched controls.…”

“…CGR method has been used to display DNA fractal properties [58][59][60][61] as modified to visualize heteroplasmic mutations peculiar to mtDNA [33]. Parameter β, from our fractal lacunarity method based on hyperbola model function [62][63][64][65], is the measure used to quantitatively characterize PD on the basis of mutated mtDNA. It is worth noting that lacunarity parameter β, in this case, represents a holistic estimate of mtDNA changes comprehensive of number, type, and dislocation of mutation(s), the combination of which could be responsible of disease onset and progression.…”

Automatic detection of osteoporosis based on hybrid genetic swarm fuzzy classifier approaches

“…3 Although BMD is a significant predictor of fracture risk, it is a generic factor and does not differentiate between the cortical and trabecular bones or predict much about the internal structure of the bone. 4 However, dental radiography is a great tool to observe the alterations of the mandibular cortex as well as the trabecular bone. 5 Computer-assisted image analysis is useful to visualize and evaluate the bone architecture directly from the dental panoramic radiograph (DPR), thus reducing human intervention.…”

Bone health in type 1 diabetes: focus on evaluation and treatment in clinical practice

“…This promising approach is able to quantify morpho-functional changes in both aging and pathology. In this particular context, fractal lacunarity seems to be the proper tool to characterize trabecular bone architecture as it is able to describe both discontinuity of bone network and sizes of bone marrow spaces, whose changes are an index of bone fracture risk [70]. Therefore, prospective studies are needed to investigate the usefulness of these novel promising techniques in the prediction of fracture risk in T1D.…”