Body composition estimation from selected slices:equations computed from a new semi-automatic thresholding method developed on whole-body CT scans

Background Estimating volumes and masses of total body components is important for the study and treatment monitoring of nutrition and nutrition-related disorders, cancer, joint replacement, energy-expenditure and exercise physiology. While several equations have been offered for estimating total body components from MRI slices, no reliable and tested method exists for CT scans. For the first time, body composition data was derived from 41 high-resolution whole-body CT scans. From these data, we defined equations for estimating volumes and masses of total body AT and LT from corresponding tissue areas measured in selected CT scan slices. Methods We present a new semi-automatic approach to defining the density cutoff between adipose tissue (AT) and lean tissue (LT) in such material. An intra-class correlation coefficient (ICC) was used to validate the method. The equations for estimating the whole-body composition volume and mass from areas measured in selected slices were modeled with ordinary least squares (OLS) linear regressions and support vector machine regression (SVMR). Results and Discussion The best predictive equation for total body AT volume was based on the AT area of a single slice located between the 4th and 5th lumbar vertebrae (L4-L5) and produced lower prediction errors (|PE| = 1.86 liters, %PE = 8.77) than previous equations also based on CT scans. The LT area of the mid-thigh provided the lowest prediction errors (|PE| = 2.52 liters, %PE = 7.08) for estimating whole-body LT volume. We also present equations to predict total body AT and LT masses from a slice located at L4-L5 that resulted in reduced error compared with the previously published equations based on CT scans. The multislice SVMR predictor gave the theoretical upper limit for prediction precision of volumes and cross-validated the results

"Putting flesh and fat back onto the bones": A 3D analysis of the influence of body composition and mass on bone architecture

Univerzita Karlova Přírodovědecká fakulta Antropologie a Genetika člověka Alizé Lacoste Jeanson, M.Sc. "NÁVRAT SVALŮ A TUKU ZPĚT NA KOSTI": 3D ANALÝZA VLIVU TĚLESNÉ KOMPOZICE A HMOTNOSTI NA KOSTNÍ ARCHITEKTURU "PUTTING FLESH AND FAT BACK ONTO THE BONES": A 3D ANALYSIS OF THE INFLUENCE OF BODY COMPOSITION AND MASS ON BONE ARCHITECTURE Disertačnn prace Doctoral thesis Školitel Supervisor: Prof. RNDr. Jaroslav Brůžek, CSc, PhD, HDR Praha, 2018 Prague, 2018 Charles University Faculty of Science Department of Anthropology and Human Genetics Abstract The understanding of biomechanics is essential to various studies in bioanthropology. Bone is a living tissue that constantly remodels in order to functionally adapt to biomechanical constrains. Long bones diaphyses in particular have been subjected to various analyses notably because the application of beam engineering principles has rendered possible the evaluation of their resistance to various directional constrains based on their shape. Body mass estimation methods lie on this principle. Body mass is partially used since the nineties as a proxy to control the influence of body size on bone's architecture prior to interpreting variations between populations. More recently, they have been used to estimate physical status (i.e. emaciation, norm, obesity)...

"Návrat svalů a tuku zpět na kosti": 3D analýza vlivu tělesné kompozice a hmotnosti na kostní architekturu

Univerzita Karlova Přírodovědecká fakulta Antropologie a Genetika člověka Alizé Lacoste Jeanson, M.Sc. "NÁVRAT SVALŮ A TUKU ZPĚT NA KOSTI": 3D ANALÝZA VLIVU TĚLESNÉ KOMPOZICE A HMOTNOSTI NA KOSTNÍ ARCHITEKTURU "PUTTING FLESH AND FAT BACK ONTO THE BONES": A 3D ANALYSIS OF THE INFLUENCE OF BODY COMPOSITION AND MASS ON BONE ARCHITECTURE Disertačnn prace Doctoral thesis Školitel Supervisor: Prof. RNDr. Jaroslav Brůžek, CSc, PhD, HDR Praha, 2018 Prague, 2018 Charles University Faculty of Science Department of Anthropology and Human Genetics Abstrakt Porozumění biomechanice je nezbytné pro různé studie v bioantropologii. Kost je živá tkáň, která se neustále remodeluje, aby se funkčně přizpůsobila biomechanickým omezením. Studovány jsou zejména diafýzy dlouhých kostí, které následují principy tzv. "beam engineering" (studium pevnosti stavebních konstrukcí), což umožňuje hodnotit odolnost kostí vůči různým směrovým omezením na základě jejich tvaru. Na tomto vztahu jsou založeny metody odhadu tělesné hmotnosti. Jsou částečně používány od devadesátých let jako prostředník ke kontrole vlivu tělesné velikosti na kostní architekturu pro interpretaci variability mezi populacemi. V současné době se používají také k odhadu fyzického stavu (např. podváha, normální váha, obezita). Na souboru 64 jedinců se známou...Univerzita Karlova Přírodovědecká fakulta Antropologie a Genetika člověka Alizé Lacoste Jeanson, M.Sc. "NÁVRAT SVALŮ A TUKU ZPĚT NA KOSTI": 3D ANALÝZA VLIVU TĚLESNÉ KOMPOZICE A HMOTNOSTI NA KOSTNÍ ARCHITEKTURU "PUTTING FLESH AND FAT BACK ONTO THE BONES": A 3D ANALYSIS OF THE INFLUENCE OF BODY COMPOSITION AND MASS ON BONE ARCHITECTURE Disertačnn prace Doctoral thesis Školitel Supervisor: Prof. RNDr. Jaroslav Brůžek, CSc, PhD, HDR Praha, 2018 Prague, 2018 Charles University Faculty of Science Department of Anthropology and Human Genetics Abstract The understanding of biomechanics is essential to various studies in bioanthropology. Bone is a living tissue that constantly remodels in order to functionally adapt to biomechanical constrains. Long bones diaphyses in particular have been subjected to various analyses notably because the application of beam engineering principles has rendered possible the evaluation of their resistance to various directional constrains based on their shape. Body mass estimation methods lie on this principle. Body mass is partially used since the nineties as a proxy to control the influence of body size on bone's architecture prior to interpreting variations between populations. More recently, they have been used to estimate physical status (i.e. emaciation, norm, obesity)....Katedra antropologie a genetiky člověkaDepartment of Anthropology and Human GeneticsPřírodovědecká fakultaFaculty of Scienc

Distributed under Creative Commons CC-BY 4.0 Body composition estimation from selected slices: equations computed from a new semi-automatic thresholding method developed on whole-body CT scans

ABSTRACT Background. Estimating volumes and masses of total body components is important for the study and treatment monitoring of nutrition and nutrition-related disorders, cancer, joint replacement, energy-expenditure and exercise physiology. While several equations have been offered for estimating total body components from MRI slices, no reliable and tested method exists for CT scans. For the first time, body composition data was derived from 41 high-resolution whole-body CT scans. From these data, we defined equations for estimating volumes and masses of total body AT and LT from corresponding tissue areas measured in selected CT scan slices. Methods. We present a new semi-automatic approach to defining the density cutoff between adipose tissue (AT) and lean tissue (LT) in such material. An intra-class correlation coefficient (ICC) was used to validate the method. The equations for estimating the whole-body composition volume and mass from areas measured in selected slices were modeled with ordinary least squares (OLS) linear regressions and support vector machine regression (SVMR). Results and Discussion. The best predictive equation for total body AT volume was based on the AT area of a single slice located between the 4th and 5th lumbar vertebrae (L4-L5) and produced lower prediction errors (|PE| = 1.86 liters, %PE = 8.77) than previous equations also based on CT scans. The LT area of the mid-thigh provided the lowest prediction errors (|PE| = 2.52 liters, %PE = 7.08) for estimating whole-body LT volume. We also present equations to predict total body AT and LT masses from a slice located at L4-L5 that resulted in reduced error compared with the previously published equations based on CT scans. The multislice SVMR predictor gave the theoretical upper limit for prediction precision of volumes and cross-validated the results

Detecting menarcheal status by stages of dental mineralization : a prospective statistical study

International audienc

Rich table but short life: Diffuse idiopathic skeletal hyperostosis in Danish astronomer Tycho Brahe (1546-1601) and its possible consequences

The exhumation of Danish astronomer Tycho Brahe (1546–1601) was performed in 2010 to verify speculative views on the cause of his death. Previous analyses of skeletal and hair remains recovered from his grave refuted the presumption that he died from poisoning. These studies also outlined the possibility that he actually died from an acute illness, echoing the rather vague and inaccurate testimony of some historical records. We performed a detailed paleopathological analysis of Tycho Brahe’s skeletal remains, along with a reconstruction of his diet based on carbon and nitrogen stable isotopes analysis and an estimate of his physical status (relative body fat) based on medullar and cortical dimensions of the femoral shaft. The astronomer’s remains exhibit bone changes indicative of diffuse idiopathic skeletal hyperostosis (DISH). The study further allows us to classify him as obese (100% reliability according to our decision tree designed from Danish males), and points out his rich diet (high input of animal protein and/or marine resources) and high social status. Comorbidities of DISH and obesity are reviewed, and their influence on health status is discussed. We further consider some conditions associated with metabolic syndrome as possible causes of Tycho Brahe’s final symptoms (urinary retention, renal failure and coma), including diabetes, alcoholic ketoacidosis and benign prostatic hypertrophy. Although a definite and specific diagnosis cannot be established, our study points to today’s civilization diseases often associated with DISH and metabolic syndrome as the possible cause of death of Tycho Brahe

Anterior view of the thoracic spine (T2–T12).

<p>A flowing ossification is present along the right side of the vertebrae. Also note the left sided bony bridge that leads to fusion of T3 and T4. Scale: 2 cm (Photo Marek Jantač).</p