Task–based Optimization of In–Vivo Micro–CT Scan Protocols using Energy Integrating and Photon Counting Detectors

2017 ◽  
Author(s):  
Carsten Funck ◽  
Joscha Maier ◽  
Marc Kachelries ◽  
Jan Kuntz ◽  
Stefan Sawall
Keyword(s):  
Ct Scan ◽  
Photon Counting ◽  
Micro Ct ◽  
Photon Counting Detectors

Multi bin energy-sensitive micro-CT using large area photon-counting detectors Timepix

2022 ◽  
Vol 17 (01) ◽  
pp. C01028
Author(s):  
J. Dudak ◽  
J. Zemlicka
Keyword(s):  
Photon Counting ◽  
Dual Energy ◽  
Urinary Stones ◽  
Dual Energy Ct ◽  
Micro Ct ◽  
Single Object ◽  
Large Area ◽  
Intravenous Contrast ◽  
Photon Counting Detector ◽  
Photon Counting Detectors

Abstract X-ray micro-CT has become a popular and widely used tool for the purposes of scientific research. Although the current state-of-the-art micro-CT is on a high technology level, it still has some known limitations. One of the relevant issues is an inability to clearly identify and quantify specific materials. The mentioned drawback can be solved by the energy-sensitive CT approach. Dual-energy CT, which is already frequently used in human medicine, offers the identification of two different materials; for example, it differentiates an intravenous contrast agent from bone or it can indicate the composition of urinary stones. Resolving a larger number of material components within a single object is beyond the capabilities of dual-energy CT. Such an approach requires a higher number of measurements using different photon energies. A possible solution for multi bin, or so-called spectral CT, is the application of photon-counting detectors. Photon counting technology offers an integrated circuitry capable of resolving the energy of incoming photons in each pixel. Therefore, it is possible to collect data in user-defined energy windows. This contribution evaluates the applicability of the large-area photon-counting detector Timepix for multi bin energy-sensitive micro-CT. It presents an experimental phantom study focused on the simultaneous K-edge-based identification and quantification of multiple contrast agents within a single object. The paper describes the collection of multiple energy bins using the Timepix detector operated in the photon counting mode, explains the data processing, and demonstrates the results obtained from an in-house implemented basis material decomposition algorithm.

An investigation into the temporal stability of CdTe-based photon counting detectors during spectral micro-CT acquisitions

2015 ◽  
Vol 1 (2) ◽  
pp. 025205 ◽  
Author(s):  
Marcus Zuber ◽  
Elias Hamann ◽  
Rafael Ballabriga ◽  
Michael Campbell ◽  
Michael Fiederle ◽  
...  
Keyword(s):  
Temporal Stability ◽  
Photon Counting ◽  
Micro Ct ◽  
Photon Counting Detectors

Increased separability of K-edge nanoparticles by photon-counting detectors for spectral micro-CT

2018 ◽  
Vol 26 (5) ◽  
pp. 707-726 ◽  
Author(s):  
Matthew Getzin ◽  
Josephine J. Garfield ◽  
David S. Rundle ◽  
Uwe Kruger ◽  
Anthony P.H. Butler ◽  
...  
Keyword(s):  
Photon Counting ◽  
Micro Ct ◽  
Photon Counting Detectors

Tantalum superconducting tunnel junctions for photon counting detectors

2002 ◽  
Vol 12 (3) ◽  
pp. 145-148
Author(s):  
C. Jorel ◽  
P. Feautrier ◽  
J.-C. Villégier ◽  
A. Benoit
Keyword(s):  
Tunnel Junctions ◽  
Photon Counting ◽  
Superconducting Tunnel Junctions ◽  
Photon Counting Detectors

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

2020 ◽  
Vol 4 (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.

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

2009 ◽  
Vol 79 (4) ◽  
pp. 703-714 ◽  
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.

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

2015 ◽  
Vol 5 (1) ◽  
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.

Residual-limb shape change: three-dimensional CT scan measurement and depiction in vivo.

Radiology ◽  
1996 ◽  
Vol 200 (3) ◽  
pp. 843-850 ◽  
Author(s):  
K E Smith ◽  
P K Commean ◽  
M W Vannier
Keyword(s):  
Ct Scan ◽  
Shape Change ◽  
Three Dimensional ◽  
Residual Limb
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