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To improve the automation degree and provide a novel real-time, in situ measurement methods of optimizing real boiler control, tunable diode absorption spectroscopy (TDLAS) combined with computed tomography reconstruction was proposed by theoretical analysis and experimental validation. It was proved by simulation that the peak location could be reconstructed and the relative values could be distinguished in case of only two projections. Six measuring grid was arranged to obtain the reconstructed 2-D temperature distribution. The result shows that the correlation coefficient between the averaged temperature and load is 0. 91. Linear regression analysis showes that the coefficient of determination is 0. 88. The averaged temperature could represent the real-time total radiation, which can be used to avoid over adjusting and obtain the heat value. The 2-D temperature distribution can be used to leveling the boiler. It was concluded that this method provides important support to the non-intrusive in-situ temperature measurement and study of optimizing combustion control. [ABSTRACT FROM AUTHOR]

Abstract Background S1-AI technique may be used as a salvage technique in pelvic fixation of complex spinal deformity surgery. However, the proper detailed parameters in the Chinese population has not been analyzed before to instruct S1-AI screws placement and to ensure the safety of clinical application while the trajectory in pelvic changes significantly at each angle. Results The ideal S1AI screw trajectory could be obtained in 28 of 30 female patient images (93.3%) and in all of the male patient images (100%). The screws that have already been used clinically in S2AI pathways can be applied in S1AI fixations. Conclusion It is feasible to place S1AI screws in 93.3% of female Chinese adult patients and in all male Chinese patients. Preoperative CT reconstruction should be performed to evaluate proper trajectory parameters and to avoid anterior violation.

Synchrotron-based in-line phase-contrast computed tomography (PC-CT) allows soft tissue to be imaged with sub-gross resolution and has potential to be used as a diagnostic tool. The reconstruction and processing of in-line PC-CT datasets is a computationally demanding task; thus, an efficient and user-friendly software program is desirable. Four freeware programs ( NRecon, PITRE, H-PITRE and Athabasca Recon) were compared for the availability of features such as dark- and flat-field calibration, beam power normalization, ring artifact removal, and alignment tools for optimizing image quality. An in-line PC-CT projection dataset (3751 projections, 180° rotation, 10.13 mm × 0.54 mm) was collected from a formalin-fixed canine prostate at the Biomedical Imaging and Therapy Bending Magnet (BMIT-BM) beamline of the Canadian Light Source. This dataset was processed with each of the four software programs and usability of the program was evaluated. Efficiency was assessed by how each program maximized computer processing power during computation. Athabasca Recon had the least-efficient memory usage, least user-friendly interface, and lacked a ring artifact removal feature. NRecon, PITRE and H-PITRE produced similar quality images, but the Athabasca Recon reconstruction suffered from the lack of a native ring remover algorithm. The 64-bit version of NRecon uses GPU (graphics processor unit) memory for accelerated processing and is user-friendly, but does not provide necessary parameters for in-line PC-CT data, such as dark-field and flat-field correction and beam power normalization. PITRE has many helpful features and tools, but lacks a comprehensive user manual and help section. H-PITRE is a condensed version of PITRE and maximizes computer memory for efficiency. To conclude, NRecon has fewer imaging processing tools than PITRE and H-PITRE, but is ideal for less experienced users due to a simple user interface. Based on the quality of reconstructed images, efficient use of computer memory and parameter availability, H-PITRE was the preferred of the four programs compared. [ABSTRACT FROM AUTHOR]

Purpose: The purposes of this study were to characterize the clinical and radiological features of type 1 and type 2 atlantoaxial rotatory dislocations (AARD) and to evaluate the outcome of the manual reduction maneuver for these types of dislocations in pediatric patients. Methods: This study considered 12 pediatric patients with AARD who were treated between January 2003 and March 2013. The diagnosis was established by clinical findings and 3D-CT. All of the patients were treated by closed manual reduction and then a cervical orthosis was performed. All of the patients were followed up at regular intervals. Results: The causes of the AARD were trauma (91.67 %) and infection (8.33 %). The time between onset of symptoms and admission to the hospital ranged from 16 days to 6 months. In radiological evaluation, the mean rotational angulation of the patients was 30.58°. The 3D-CT examination showed that six patients (50 %) had type 1 dislocation and six patients (50 %) had type 2 dislocation. All of the patients were treated by closed manual reduction and then a cervical orthosis was performed. For 11 patients (91.67 %), dislocation was successfully reducted and maintained. One patient (8.33 %) underwent surgery, following recurrence of the second closed reduction maneuver. Conclusion: This preceding treatment method has successfully produced a fast and recurrence-free alignment on all except one of our patients. This technique can be a useful treatment alternative in carefully selected AARD cases. Future research is encouraged to improve decision making in the application of this treatment method and provide additional validation of the current findings. [ABSTRACT FROM AUTHOR]

Convergence of iterative algorithms can be improved by updating groups of voxels sequentially rather than updating the whole image simultaneously. The optimal way is to choose groups of uncoupled voxels, i.e. voxels spread over the reconstruction volume. While this is most efficient for convergence reasons, updating groups of spread voxels is less efficient regarding memory access and computational burden. In this work, an image-block update scheme is presented that updates relatively large groups of voxels simultaneously while keeping a considerable gain in convergence. The sequential image-block update can also be combined with ordered subsets. This image-block or patchwork scheme is applied both to transmission and emission maximum likelihood algorithms. [ABSTRACT FROM PUBLISHER]

In this paper, we describe the work done in order to run the CT 3-D reconstruction algorithm on the 120 GB raw data from the more than 25\thinspace000 radiographs acquired from the Kongo Rikishi (XIII century) Japanese wooden statue. The work was done using the Microsoft (Redmond) HPC cluster and then on a local cluster at the INFN of Bologna. A speed-up factor of 75 was reached. [ABSTRACT FROM PUBLISHER]

A novel quasi-linearization method was developed for CT image reconstruction in scanners with a multi-energy detector system. The non-linear equation relating material attenuation coefficients to measured data was reduced to a system of linear equations by means of piece-wise constant approximation of attenuation functions. A material decomposition algorithm was proposed to obtain a physically meaningful solution of this system for the case of N = 2 (dual-energy CT scanners). Image reconstruction methods (the new one and the classical filtered backprojection with beam-hardening correction) were implemented to measured CT data. The new method consistently provides more accurate density results in image reconstruction for the objects containing materials with significantly different attenuation coefficients. [ABSTRACT FROM AUTHOR]

Background: S1-AI technique may be used as a salvage technique in pelvic fixation of complex spinal deformity surgery. However, the proper detailed parameters in the Chinese population has not been analyzed before to instruct S1-AI screws placement and to ensure the safety of clinical application while the trajectory in pelvic changes significantly at each angle. Results: The ideal S1AI screw trajectory could be obtained in 28 of 30 female patient images (93.3%) and in all of the male patient images (100%). The screws that have already been used clinically in S2AI pathways can be applied in S1AI fixations. Conclusion: It is feasible to place S1AI screws in 93.3% of female Chinese adult patients and in all male Chinese patients. Preoperative CT reconstruction should be performed to evaluate proper trajectory parameters and to avoid anterior violation. [ABSTRACT FROM AUTHOR]

The accurate position of the center of rotation (COR) is a key factor to ensure the quality of computed tomography (CT) reconstructed images. The classic cross-correlation matching algorithm can not satisfy the requirements of high-quality CT imaging when the projection angle is 0 and 180°, and thus needs to be improved and innovated. In this study, considering the symmetric characteristic of the 0° and flipped 180° projection data in sinogram, a novel COR correction algorithm based on the translation and match of the 0° and 180° projection data was proposed. The OTSU method was applied to reduce noise on the background, and the minimum offset of COR was quantified using the L 1 -norm, and then a precise COR was obtained for the image correction and reconstruction. The Sheep-Logan simulation model with random gradients and Gaussian noise and the real male SD rats samples which contained the heterogenous tooth image and the homogenous liver image, were adopted to verify the performance of the new algorithm and the cross-correlation matching algorithm. The results show that the proposed algorithm has better robustness and higher accuracy of the correction (when the sampled data is from 10% to 50% of the full projection data, the COR value can still be measured accurately using the proposed algorithm) with less computational burden compared with the cross-correlation matching algorithm, and it is able to significantly improve the quality of the reconstructed images.

Background: Percutaneous cervical pedicle screw fixation has been proven to be an effective method of cervical screw instrumentation, which has the advantages of less invasiveness and low blood loss. Emerging evidence has indicated that the cervical spinous process plays an important role in percutaneous spine surgery. However, there is a limited amount of information on the fundamental research of pedicle and its associated imaging parameter measurement. The purpose of this study was to measure the anatomic data of the pedicle screw channel (PSC) using reverse engineering and three-dimensional reconstruction, and also to discuss the three-dimensional relationship between the cervical spinous process and the pedicle screw channel., Methods: Twenty adult subjects (10 males, 10 females, age range 19-46 years) were studied using the method of three-dimensional CT reconstruction and reverse engineering. The centrum was divided into 10 equal parts from front to back. The bisectors were defined as borderline depths of the centrum, from front to back, 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 0% of borderline depths were presented. Then, a 3D coordinate system was constructed to measure all the data, including the radius of the inscribed circle, the length of the PSC, the insertion angle, the distances from entry point to cervical spinous process and skin depth. All the indexes were measured from 70% to 90% borderline depth., Results: The radius of the inscribed circles from C 3 to C 7 at 90% borderline depth were 2.94 ± 0.55 mm, 3.04 ± 0.40 mm, 3.15 ± 0.36 mm, 3.28 ± 0.47 mm, 3.89 ± 0.54 mm, respectively. The lengths of the PSC were between 25 and 32 mm. The insertion angles for 70% to 90% borderline depth were 28.33°, 34.28°, 37.92°, respectively. The relationship between the PSC and spinous process was measured as the distance from the entry point to the end of the spinous process, which were, respectively, 26.91 mm, 28.18 mm, 30.03 mm, 35.67 mm, 41.99 mm from C 3 to C 7 .The distance from the skin to the entry point of C 3-7 increased gradually., Conclusions: The measurements of this study could provide detailed information for percutaneous cervical screw fixation. The data of the relationship between the cervical spinous process and the pedicle screw channel present valuable technical information for the design, optimization and clinical application of the aiming device for percutaneous cervical pedicle screw fixation. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

To investigate the morphometric data of the lumbar spinous process dimensions in Chinese population. Forty-six adult subjects (22 males, 24 females, age range 26-45 years) were studied using the method of the three dimensional CT reconstruction in our hospital. The following parameters were measured: the distance between two adjacent spinous processes (DB), distance across the two adjacent spinous processes (DA), thickness of central of spinous processes (TC), thickness of the superior margin of spinous processes (TS), thickness of the inferior margin of spinous processes (TI), and height of spinous processes (H). Variance and correlation analysis were conducted for these data. Data met with normal distribution and homogeneity of variance. Similar variation trend of the parameters of lumbar spinous process for male and female was found. DB became shorter gradually from L1-2 to L4-5, and increased at the L5-S1. DA became larger from T12-L1 to L1-2 for male and L2-3 for female, and then became shorter from L1-2 for male and L2-3 for female, respectively. The largest H of male and female were both noted at L3. TS of the adjacent spinous processes were lower than that of TI for male and female. Statistical significance between male and female were found in H, TC, TS, TI (L1, L3 and L4), and DA (except for L4-5). Compared to male, the spinous processes of female were shorter, thinner and lower. These data may be useful for clinical application and the design of interspinous implant in Chinese population.