Effect of sex steroids on peak bone density of growing rabbits

To determine the effect of sex hormones on bone density (BD) during growth, longitudinal quantitative computed tomography (QCT) measurements were obtained in growing, castrated New Zealand White rabbits following administration of normal saline, testosterone, or estrogen from 6 wk of age until the time of skeletal maturity. Vertebral QCT densities increased during growth, were highest at the time of epiphyseal closure, and were significantly greater (P less than 0.001) in hormone-treated animals. In vivo QCT measurements in 12 vertebraes correlated strongly (r = 0.92) with percentage of calcium per weight assessed in vitro by neutron activation analysis.

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Vertebral bone density evaluated by dual-energy X-ray absorptiometry and quantitative computed tomography in vitro

Bone ◽

10.1016/s8756-3282(98)00091-x ◽

1998 ◽

Vol 23 (3) ◽

pp. 283-290 ◽

Cited By ~ 47

Author(s):

E.N. Ebbesen ◽

J.S. Thomsen ◽

H. Beck-Nielsen ◽

H.J. Nepper-Rasmussen ◽

Li Mosekilde

Keyword(s):

Computed Tomography ◽

Bone Density ◽

Quantitative Computed Tomography ◽

Dual Energy ◽

Vertebral Bone ◽

X Ray

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Guidelines for the assessment of bone density and microarchitecture in vivo using high-resolution peripheral quantitative computed tomography

Osteoporosis International ◽

10.1007/s00198-020-05438-5 ◽

2020 ◽

Vol 31 (9) ◽

pp. 1607-1627 ◽

Cited By ~ 11

Author(s):

D.E. Whittier ◽

S.K. Boyd ◽

A.J. Burghardt ◽

J. Paccou ◽

A. Ghasem-Zadeh ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Bone Density ◽

Quantitative Computed Tomography ◽

Peripheral Quantitative Computed Tomography

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Assessment of broadband ultrasound attenuation in the os calcis in vitro

Clinical Science ◽

10.1042/cs0780221 ◽

1990 ◽

Vol 78 (2) ◽

pp. 221-225 ◽

Cited By ~ 81

Author(s):

E. V. McCloskey ◽

S. A. Murray ◽

D. Charlesworth ◽

C. Miller ◽

J. Fordham ◽

...

Keyword(s):

Computed Tomography ◽

Soft Tissues ◽

Quantitative Computed Tomography ◽

Broadband Ultrasound Attenuation ◽

Mineral Density ◽

Os Calcis ◽

Ultrasound Attenuation ◽

Physical Density

1. We have examined the relationship between the attenuation of broadband ultrasound in the os calcis in vitro and its bone mineral density measured by quantitative computed tomography and by physical density. 2. Broadband ultrasound attenuation was found to correlate closely with physical density (r = 0.85, P < 0.0001), but the correlation was less than that observed between quantitative computed tomography and physical density (r = 0.92, P < 0.0001). Measurements of broadband ultrasound attenuation and quantitative computed tomography were significantly correlated (r = 0.80, P < 0.0001). 3. Partial correlation analysis showed a significant relationship between broadband ultrasound attenuation and bone density, but when the effect of physical density was taken into account no significant correlation was found between broadband ultrasound attenuation and quantitative computed tomography (r = 0.08, not significant). 4. Broadband ultrasound attenuation in three prospective amputees showed a high degree of concordance between measurements in vivo and in vitro, with no interference by surrounding soft tissues. 5. The correlation between physical density and broadband ultrasound attenuation was independent of quantitative computed tomography, suggesting that the technique measures aspects of density which differ from its mineral density. Broadband ultrasound attenuation holds promise as a reproducible, rapid, radiation-free assessment of skeletal status.

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Peripheral Quantitative Computed Tomography in Human Long Bones: Evaluation of In Vitro and In Vivo Precision

Journal of Bone and Mineral Research ◽

10.1359/jbmr.1998.13.5.871 ◽

1998 ◽

Vol 13 (5) ◽

pp. 871-882 ◽

Cited By ~ 196

Author(s):

Harri Sievänen ◽

Virpi Koskue ◽

Anne Rauhio ◽

Pekka Kannus ◽

Ari Heinonen ◽

...

Keyword(s):

Computed Tomography ◽

Quantitative Computed Tomography ◽

Peripheral Quantitative Computed Tomography ◽

Long Bones

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Tantalum Oxide Nanoparticles as Versatile Contrast Agents for X-ray Computed Tomography

10.26434/chemrxiv.11845572.v1 ◽

2020 ◽

Author(s):

Shatadru Chakravarty ◽

Jeremy Hix ◽

Kaitlyn Wieweora ◽

Maximilian Volk ◽

Elizabeth Kenyon ◽

...

Keyword(s):

Computed Tomography ◽

Contrast Agents ◽

Mesoporous Silica Nanoparticles ◽

Sol Gel ◽

Tantalum Oxide ◽

High Signal ◽

Drug Delivery Vehicles ◽

X Ray Computed

Here we describe the synthesis, characterization and in vitro and in vivo performance of a series of tantalum oxide (TaOx) based nanoparticles (NPs) for computed tomography (CT). Five distinct versions of 9-12 nm diameter silane coated TaOx nanocrystals (NCs) were fabricated by a sol-gel method with varying degrees of hydrophilicity and with or without fluorescence, with the highest reported Ta content to date (78%). Highly hydrophilic NCs were left bare and were evaluated in vivo in mice for micro-CT of full body vasculature, where following intravenous injection, TaOx NCs demonstrate high CT contrast, circulation in blood for ~ 3 h, and eventual accumulation in RES organs; and following injection locally in the mammary gland, where the full ductal tree structure can be clearly delineated. Partially hydrophilic NCs were encapsulated within mesoporous silica nanoparticles (MSNPs; TaOx@MSNPs) and hydrophobic NCs were encapsulated within poly(lactic-co-glycolic acid) (PLGA; TaOx@PLGA) NPs, serving as potential CT-imagable drug delivery vehicles. Bolus intramuscular injections of TaOx@PLGA NPs and TaOx@MSNPs to mimic the accumulation of NPs at a tumor site produce high signal enhancement in mice. In vitro studies on bare NCs and formuated NPs demonstrate high cytocompatibility and low dissolution of TaOx. This work solidifies that TaOx-based NPs are versatile contrast agents for CT.

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