In vivo micro-CT scanning of a rabbit distal femur: Repeatability and reproducibility

Cotton-wool-like bioresorbable bone void fillers consisting of β-tricalcium phosphate (β-TCP), siloxane-containing vaterite (SiV) and poly (L-lactic acid) (PLLA) was prepared by an electrospinning method. The fibers, which were 50 ~ 150 μm-width with 10 ~ 30 μm-thickness, were entwined. The resulting cotton-wool-like material showed mechanical flexibility and excellent shapability; it showed easy, excellent mechanical-fixation in defects. The in vivo performance of this material was examined in the distal femur in New Zealand white rabbits. It was evaluated using micro CT and histologic analyses at time points of 6 and 12 weeks. These analyses of the defect sites verified normal healing response and new bone formation. The in vivo testing with rabbits showed good biocompatibility and excellent osteogenic ability.

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Skull shape differentiation of black and white olms (Proteus anguinus anguinus and Proteus a. parkelj): an exploratory analysis with micro-CT scanning

Contributions to Zoology ◽

10.1163/18759866-08202004 ◽

2013 ◽

Vol 82 (2) ◽

pp. 107-114 ◽

Cited By ~ 10

Author(s):

Ana Ivanović ◽

Gregor Aljančič ◽

Jan W. Arntzen

Keyword(s):

Morphological Differentiation ◽

Ct Scanning ◽

Exploratory Analysis ◽

Micro Ct ◽

Black And White ◽

Necturus Maculosus ◽

Proteus Anguinus ◽

Evolutionary Trajectories ◽

Morphological Detail ◽

Shape Changes

We performed an exploratory analysis of the morphology of the cranium in the white olm (Proteus anguinus anguinus) and the black olm (P. a. parkelj) with micro-CT scanning and geometric morphometrics. The mudpuppy (Necturus maculosus) was used as an outgroup. The black olm falls outside the white olm morphospace by a markedly wider skull, shorter vomers which are positioned further apart and by laterally positioned squamosals and quadrates relative to the palate (the shape of the buccal cavity). On account of its robust skull with more developed premaxillae a shorter otico-occipital region, the black olm is positioned closer to Necturus than are the studied specimens of the white olm. The elongated skull of the white olm, with an anteriorly positioned jaw articulation point, could be regarded as an adaptation for improved feeding success, possibly compensating for lack of vision. As yet, the alternative explanations on the evolution of troglomorphism in Proteus are an extensive convergence in white olms versus the reverse evolution towards less troglomorphic character states in the black olm. To further understand the evolutionary trajectories within Proteus we highlight the following hypotheses for future testing: i) morphological differentiation is smaller within than between genetically differentiated white olm lineages, and ii) ontogenetic shape changes are congruent with the shape changes between lineages. We anticipate that the morphological detail and analytical power that come with the techniques we here employed will assist us in this task.

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Modelling the skeletal muscle injury recovery using in vivo contrast-enhanced micro-CT: a proof-of-concept study in a rat model

European Radiology Experimental ◽

10.1186/s41747-020-00163-4 ◽

2020 ◽

Vol 4 (1) ◽

Cited By ~ 1

Author(s):

Bruno Paun ◽

Daniel García Leon ◽

Alex Claveria Cabello ◽

Roso Mares Pages ◽

Elena de la Calle Vargas ◽

...

Keyword(s):

Skeletal Muscle ◽

Rat Model ◽

Muscle Injury ◽

Micro Ct ◽

Skeletal Muscle Injury ◽

Monitoring Time ◽

Contrast Enhanced Ct ◽

Contrast Enhanced ◽

Injury Recovery

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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A Microcomputed Tomographic Evaluation of Root Canal Morphology of Maxillary Second Premolars in a Pakistani Cohort

Applied Sciences ◽

10.3390/app11115086 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5086

Author(s):

Mazen F. Alkahtany ◽

Saqib Ali ◽

Abdul Khabeer ◽

Shafqat A. Shah ◽

Khalid H. Almadi ◽

...

Keyword(s):

Root Canal ◽

Three Dimensional ◽

Ct Scanning ◽

Micro Ct ◽

Single Root ◽

Root Canal Morphology ◽

Spss Software ◽

Variable Morphology ◽

Canal Morphology

This study aimed to investigate variations in the root canal morphology of maxillary second premolar (MSP) teeth using microcomputed tomography (micro-CT). Sixty (N = 60) human extracted MSPs were collected and prepared for micro-CT scanning. The duration for scanning a single sample ranged between 30 and 40 min and a three-dimensional (3-D) image was obtained for all the MSPs. The images were evaluated by a single observer who recorded the canal morphology type, number of roots, canal orifices, apical foramina(s), apical delta(s), and accessory canals. The root canal configuration was categorized in agreement with Vertucci’s classification, and any configuration not in agreement with Vertucci’s classification was reported as an “additional canal configuration”. Descriptive statistics (such as mean percentages) were calculated using SPSS software. The most common types agreeing with Vertucci’s classification (in order of highest to lowest incidence) were types I, III, V, VII, II, and VI. The teeth also exhibited four additional configurations that were different from Vertucci’s classification: types 2-3, 1-2-3, 2-1-2-1, and 1-2-1-3. A single root was found in 96.7% and the majority of the samples demonstrated two canals (73.3%). Further, 80% of the teeth showed one canal orifice. The number of apical foramina’s in the teeth was variable, with 56.7% having solitary apical foramen. The accessory canal was found in 33.3%, and apical delta was found in only 20% of the samples. Variable morphology of the MSPs was detected in our study. The canal configuration most prevalent was type 1; however, the results also revealed some additional canal types.

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Design, Fabrication, and Accuracy of a Novel Noncovering Lock-Mechanism Bilateral Patient-Specific Drill Guide Template for Nondeformed and Deformed Thoracic Spines

HSS Journal ® ◽

10.1177/1556331621996331 ◽

2021 ◽

pp. 155633162199633

Author(s):

Mehran Ashouri-Sanjani ◽

Shima Mohammadi-Moghadam ◽

Parisa Azimi ◽

Navid Arjmand

Keyword(s):

Thoracic Spine ◽

Sagittal Plane ◽

Ct Scanning ◽

Entry Point ◽

In Vivo Studies ◽

Patient Specific ◽

Plane Angle ◽

Severe Scoliosis ◽

3D Printed

Background: Pedicle screw (PS) placement has been widely used in fusion surgeries on the thoracic spine. Achieving cost-effective yet accurate placements through nonradiation techniques remains challenging. Questions/Purposes: Novel noncovering lock-mechanism bilateral vertebra-specific drill guides for PS placement were designed/fabricated, and their accuracy for both nondeformed and deformed thoracic spines was tested. Methods: One nondeformed and 1 severe scoliosis human thoracic spine underwent computed tomographic (CT) scanning, and 2 identical proportions of each were 3-dimensional (3D) printed. Pedicle-specific optimal (no perforation) drilling trajectories were determined on the CT images based on the entry point/orientation/diameter/length of each PS. Vertebra-specific templates were designed and 3D printed, assuring minimal yet firm contacts with the vertebrae through a noncovering lock mechanism. One model of each patient was drilled using the freehand and one using the template guides (96 pedicle drillings). Postoperative CT scans from the models with the inserted PSs were obtained and superimposed on the preoperative planned models to evaluate deviations of the PSs. Results: All templates fitted their corresponding vertebra during the simulated operations. As compared with the freehand approach, PS placement deviations from their preplanned positions were significantly reduced: for the nonscoliosis model, from 2.4 to 0.9 mm for the entry point, 5.0° to 3.3° for the transverse plane angle, 7.1° to 2.2° for the sagittal plane angle, and 8.5° to 4.1° for the 3D angle, improving the success rate from 71.7% to 93.5%. Conclusions: These guides are valuable, as the accurate PS trajectory could be customized preoperatively to match the patients’ unique anatomy. In vivo studies will be required to validate this approach.

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Timing of Mouse Molar Formation Is Independent of Jaw Length Including Retromolar Space

Journal of Developmental Biology ◽

10.3390/jdb9010008 ◽

2021 ◽

Vol 9 (1) ◽

pp. 8

Author(s):

Daisy (Jihyung) Ko ◽

Tess Kelly ◽

Lacey Thompson ◽

Jasmene K. Uppal ◽

Nasim Rostampour ◽

...

Keyword(s):

Onset Time ◽

Ct Scanning ◽

Micro Ct ◽

Third Molars ◽

Developmental Duration ◽

Dental Lamina ◽

Permanent Molars ◽

Dental Epithelium ◽

Space Conditions

For humans and other mammals to eat effectively, teeth must develop properly inside the jaw. Deciphering craniodental integration is central to explaining the timely formation of permanent molars, including third molars which are often impacted in humans, and to clarifying how teeth and jaws fit, function and evolve together. A factor long-posited to influence molar onset time is the jaw space available for each molar organ to form within. Here, we tested whether each successive molar initiates only after a minimum threshold of space is created via jaw growth. We used synchrotron-based micro-CT scanning to assess developing molars in situ within jaws of C57BL/6J mice aged E10 to P32, encompassing molar onset to emergence. We compared total jaw, retromolar and molar lengths, and molar onset times, between upper and lower jaws. Initiation time and developmental duration were comparable between molar upper and lower counterparts despite shorter, slower-growing retromolar space in the upper jaw, and despite size differences between upper and lower molars. Timing of molar formation appears unmoved by jaw length including space. Conditions within the dental lamina likely influence molar onset much more than surrounding jaw tissues. We theorize that molar initiation is contingent on sufficient surface area for the physical reorganization of dental epithelium and its invagination of underlying mesenchyme.

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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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