Measuring Mouse Abdominal Aorta Dimensions in Vivo: A Comparison between (3D) Ultrasound and Micro-CT

Abstract Background Skeletal muscle injury characterisation during healing supports trauma prognosis. Given the potential interest of computed tomography (CT) in muscle diseases and lack of in vivo CT methodology to image skeletal muscle wound healing, we tracked skeletal muscle injury recovery using in vivo micro-CT in a rat model to obtain a predictive model. Methods Skeletal muscle injury was performed in 23 rats. Twenty animals were sorted into five groups to image lesion recovery at 2, 4, 7, 10, or 14 days after injury using contrast-enhanced micro-CT. Injury volumes were quantified using a semiautomatic image processing, and these values were used to build a prediction model. The remaining 3 rats were imaged at all monitoring time points as validation. Predictions were compared with Bland-Altman analysis. Results Optimal contrast agent dose was found to be 20 mL/kg injected at 400 μL/min. Injury volumes showed a decreasing tendency from day 0 (32.3 ± 12.0mm3, mean ± standard deviation) to day 2, 4, 7, 10, and 14 after injury (19.6 ± 12.6, 11.0 ± 6.7, 8.2 ± 7.7, 5.7 ± 3.9, and 4.5 ± 4.8 mm3, respectively). Groups with single monitoring time point did not yield significant differences with the validation group lesions. Further exponential model training with single follow-up data (R2 = 0.968) to predict injury recovery in the validation cohort gave a predictions root mean squared error of 6.8 ± 5.4 mm3. Further prediction analysis yielded a bias of 2.327. Conclusion Contrast-enhanced CT allowed in vivo tracking of skeletal muscle injury recovery in rat.

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An In Vivo 3D Micro-CT Evaluation of Tooth Movement After the Application of Different Force Magnitudes in Rat Molar

The Angle Orthodontist ◽

10.2319/071308-366.1 ◽

2009 ◽

Vol 79 (4) ◽

pp. 703-714 ◽

Cited By ~ 29

Author(s):

Carmen Gonzales ◽

Hitoshi Hotokezaka ◽

Yoshinori Arai ◽

Tadashi Ninomiya ◽

Junya Tominaga ◽

...

Keyword(s):

Tooth Movement ◽

Three Dimensional ◽

Element Model ◽

Longitudinal Change ◽

Micro Ct ◽

Linear Measurements ◽

Center Of Rotation ◽

Ct Evaluation ◽

Space Width

Abstract Objective: To investigate the precise longitudinal change in the periodontal ligament (PDL) space width and three-dimensional tooth movement with continuous-force magnitudes in living rats. Materials and Methods: Using nickel-titanium closed-coil springs for 28 days, 10-, 25-, 50-, and 100-g mesial force was applied to the maxillary left first molars. Micro-CT was taken in the same rat at 0, 1, 2, 3, 10, 14, and 28 days. The width of the PDL was measured in the pressure and tension sides from 0 to 3 days. Angular and linear measurements were used to evaluate molar position at day 0, 10, 14, and 28. The finite element model (FEM) was constructed to evaluate the initial stress distribution, molar displacement, and center of rotation of the molar. Results: The initial evaluation of PDL width showed no statistical differences among different force magnitudes. Tooth movement was registered 1 hour after force application and gradually increased with time. From day 10, greater tooth movement was observed when 10 g of force was applied. The FEM showed that the center of rotation in the molar is located in the center of five roots at the apical third of the molar roots. Conclusion: The rat's molar movement mainly consists of mesial tipping, extrusion of distal roots, intrusion of mesial root, palatal inclination, and mesial rotation. Although the initial tooth movement after the application of different force magnitudes until day 3 was not remarkably different, 10 g of force produced more tooth movement compared with heavier forces at day 28.

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Longitudinal in vivo evaluation of bone regeneration by combined measurement of multi-pinhole SPECT and micro-CT for tissue engineering

Scientific Reports ◽

10.1038/srep10238 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 16

Author(s):

Philipp S. Lienemann ◽

Stéphanie Metzger ◽

Anna-Sofia Kiveliö ◽

Alain Blanc ◽

Panagiota Papageorgiou ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Bone Formation ◽

Bone Regeneration ◽

Bone Defects ◽

Histological Evaluation ◽

Biological Processes ◽

Micro Ct ◽

Pinhole Spect

Abstract Over the last decades, great strides were made in the development of novel implants for the treatment of bone defects. The increasing versatility and complexity of these implant designs request for concurrent advances in means to assess in vivo the course of induced bone formation in preclinical models. Since its discovery, micro-computed tomography (micro-CT) has excelled as powerful high-resolution technique for non-invasive assessment of newly formed bone tissue. However, micro-CT fails to provide spatiotemporal information on biological processes ongoing during bone regeneration. Conversely, due to the versatile applicability and cost-effectiveness, single photon emission computed tomography (SPECT) would be an ideal technique for assessing such biological processes with high sensitivity and for nuclear imaging comparably high resolution (<1 mm). Herein, we employ modular designed poly(ethylene glycol)-based hydrogels that release bone morphogenetic protein to guide the healing of critical sized calvarial bone defects. By combined in vivo longitudinal multi-pinhole SPECT and micro-CT evaluations we determine the spatiotemporal course of bone formation and remodeling within this synthetic hydrogel implant. End point evaluations by high resolution micro-CT and histological evaluation confirm the value of this approach to follow and optimize bone-inducing biomaterials.

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119 CHARACTERISATION OF TEMPORAL SUBCHONDRAL BONE CHANGES IN A RAT MODEL OF LOW-DOSE MONOSODIUM IODOACETATE INDUCED OSTEOARTHRITIS: AN IN VIVO MICRO-CT STUDY

Osteoarthritis and Cartilage ◽

10.1016/s1063-4584(11)60146-5 ◽

2011 ◽

Vol 19 ◽

pp. S61-S62 ◽

Cited By ~ 1

Author(s):

G. Mohan ◽

E. Perilli ◽

J. Kuliwaba ◽

I. Parkinson ◽

J. Humphries ◽

...

Keyword(s):

Subchondral Bone ◽

Rat Model ◽

Low Dose ◽

Micro Ct ◽

Bone Changes ◽

Monosodium Iodoacetate

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SECRETION OF PROGESTERONE DURING GESTATION IN THE RAT

Journal of Endocrinology ◽

10.1677/joe.0.0790179 ◽

1978 ◽

Vol 79 (2) ◽

pp. 179-190 ◽

Cited By ~ 37

Author(s):

MRINAL K. SANYAL

Keyword(s):

Abdominal Aorta ◽

Primary Source ◽

Solvent System ◽

Peripheral Circulation ◽

Systemic Circulation ◽

Maternal Circulation ◽

Secondary Importance ◽

System Hexane ◽

Venous Plasma

The concentrations of progesterone and 5α-pregnane-3,20-dione in ovarian and uterine venous plasma and in the systemic circulation were measured during gestation in the rat. The steroids were quantified by radioimmunoassay after separation on silicic acid microcolumns with the solvent system hexane: ethyl acetate (5: 2, v/v). The concentration of progesterone in the systemic circulation was highest on days 3–4 and 13–17 of pregnancy; throughout gestation, the concentration of 5α-pregnane-3,20-dione was low in relation to that of progesterone and showed no marked changes as gestation proceeded. The level of progesterone in ovarian venous effluent was 10–20 times higher than that in the uterine vein and 20–50 times greater than that in the systemic circulation. The rate of secretion of progesterone by the ovary was highest during days 13–17 of gestation and ovariectomy during this period markedly reduced the levels of progesterone in the peripheral circulation. The concentration of progesterone in the uterine venous effluent was raised compared with the concentration in plasma from the abdominal aorta, especially on days 7 and 9 of pregnancy. These results suggest that, in vivo, the rat placenta synthesizes small amounts of progesterone and secretes it into the maternal circulation. The ovary is the primary source of progesterone during pregnancy and the placental contribution is of secondary importance. Although 4-ene-5α-reductase enzyme(s) is present in the ovary and placenta, significant quantities of the reduced progestin 5α-pregnane-3,20-dione are not secreted into the systemic circulation during gestation in the rat.

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In Vivo Quantification of Regional Circumferential Green Strain in the Thoracic and Abdominal Aorta by Two-Dimensional Spiral Cine DENSE MRI

Journal of Biomechanical Engineering ◽

10.1115/1.4040910 ◽

2019 ◽

Vol 141 (6) ◽

Cited By ~ 1

Author(s):

John S. Wilson ◽

Xiaodong Zhong ◽

Jackson Hair ◽

W. Robert Taylor ◽

John N. Oshinski

Keyword(s):

Abdominal Aorta ◽

Aortic Wall ◽

Patient Specific ◽

Peak Strain ◽

Ssfp Cine ◽

Green Strain ◽

The Mean ◽

Thoracic And Abdominal ◽

Cine Dense

Regional tissue mechanics play a fundamental role in the patient-specific function and remodeling of the cardiovascular system. Nevertheless, regional in vivo assessments of aortic kinematics remain lacking due to the challenge of imaging the thin aortic wall. Herein, we present a novel application of displacement encoding with stimulated echoes (DENSE) magnetic resonance imaging (MRI) to quantify the regional displacement and circumferential Green strain of the thoracic and abdominal aorta. Two-dimensional (2D) spiral cine DENSE and steady-state free procession (SSFP) cine images were acquired at 3T at either the infrarenal abdominal aorta (IAA), descending thoracic aorta (DTA), or distal aortic arch (DAA) in a pilot study of six healthy volunteers (22–59 y.o., 4 females). DENSE data were processed with multiple custom noise reduction techniques including time-smoothing, displacement vector smoothing, sectorized spatial smoothing, and reference point averaging to calculate circumferential Green strain across 16 equispaced sectors around the aorta. Each volunteer was scanned twice to evaluate interstudy repeatability. Circumferential Green strain was heterogeneously distributed in all volunteers and locations. The mean spatial heterogeneity index (standard deviation of all sector values divided by the mean strain) was 0.37 in the IAA, 0.28 in the DTA, and 0.59 in the DAA. Mean (homogenized) peak strain by DENSE for each cross section was consistent with the homogenized linearized strain estimated from SSFP cine. The mean difference in peak strain across all sectors following repeat imaging was −0.1±2.3%, with a mean absolute difference of 1.7%. Aortic cine DENSE MRI is a viable noninvasive technique for quantifying heterogeneous regional aortic wall strain and has significant potential to improve patient-specific clinical assessments of numerous aortopathies, as well as to provide the lacking spatiotemporal data required to refine patient-specific computational models of aortic growth and remodeling.

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