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Sakurada MA, Rabelo LEG, Haagsma IB, do Carmo Filho LC, Estrela C, Reginaldo I, Gonçalves TMSV. The effect of a blooming artifact reduction filter on the dimensional analysis of implants. Oral Surg Oral Med Oral Pathol Oral Radiol 2024:S2212-4403(24)00409-7. [PMID: 39289113 DOI: 10.1016/j.oooo.2024.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 07/22/2024] [Accepted: 08/04/2024] [Indexed: 09/19/2024]
Abstract
OBJECTIVE To assess the effect of a blooming artifact reduction (BAR) filter on cone beam computed tomography (CBCT) images in the dimensional analysis of dental implants. STUDY DESIGN Six types of implants (n = 5 for each type) composed of titanium (3 types), titanium-zirconia alloy, zirconium oxide, and titanium-aluminum-vanadium alloy, and made with 2 manufacturing processes (milled and printed) were individually installed in a bovine rib block according to the manufacturer's protocol. CBCT images were acquired with i-CAT and Carestream scanners, randomized, and analyzed without and with the e-Vol DX BAR filter (60 images for each scanner). Implant length, diameter, and thread-to-thread distance were measured by two radiologists, with a stereomicroscopic image of each implant as the reference standard for calculation of distortion in measurements. Repeated measures ANOVA with Bonferroni corrections and intraclass correlation coefficients (ICC) were applied (α = 0.05). RESULTS The BAR filter significantly reduced distortion in various parameters for specific implants, aligning closely with stereomicroscopic measurements. Titanium and printed implants showed reduced dimensional distortion regardless of BAR filter use. Carestream measurements presented smaller dimensional differences than i-CAT for most implants and parameters, especially without BAR (P < .05). Interexaminer reliability was good to excellent, with ICC ranging from 0.80 to 0.95. CONCLUSIONS The BAR filter can enhance implant dimensional analysis, although variations based on implant material and manufacturing process were observed.
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Affiliation(s)
- Matheus Akira Sakurada
- Department of Dentistry, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil
| | | | | | | | - Carlos Estrela
- Department of Stomatologic Science, Federal University of Goiás (UFG), Goiânia, Goiás, Brazil
| | - Isabela Reginaldo
- Dentistry Department, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil
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Li B, Inscoe CR, Xu S, Capo T, Tyndall DA, Lee YZ, Lu J, Zhou O. A carbon nanotube x-ray source array designed for a new multisource cone beam computed tomography scanner. Phys Med Biol 2024; 69:075028. [PMID: 38471174 DOI: 10.1088/1361-6560/ad3323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 03/12/2024] [Indexed: 03/14/2024]
Abstract
Cone beam computed tomography (CBCT) is known to suffer from strong scatter and cone beam artifacts. The purpose of this study is to develop and characterize a rapidly scanning carbon nanotube (CNT) field emission x-ray source array to enable a multisource CBCT (ms-CBCT) image acquisition scheme which has been demonstrated to overcome these limitations. A CNT x-ray source array with eight evenly spaced focal spots was designed and fabricated for a medium field of view ms-CBCT for maxillofacial imaging. An external multisource collimator was used to confine the radiation from each focal spot to a narrow cone angle. For ms-CBCT imaging, the array was placed in the axial direction and rapidly scanned while rotating continuously around the object with a flat panel detector. The x-ray beam profile, temporal and spatial resolutions, energy and dose rate were characterized and evaluated for maxillofacial imaging. The CNT x-ray source array achieved a consistent focal spot size of 1.10 ± 0.04 mm × 0.84 ± 0.03 mm and individual beam cone angle of 2.4°±0.08 after collimation. The x-ray beams were rapidly switched with a rising and damping times of 0.21 ms and 0.19 ms, respectively. Under the designed operating condition of 110 kVp and 15 mA, a dose rate of 8245μGy s-1was obtained at the detector surface with the inherent Al filtration and 2312μGy s-1with an additional 0.3 mm Cu filter. There was negligible change of the x-ray dose rate over many operating cycles. A ms-CBCT scan of an adult head phantom was completed in 14.4 s total exposure time for the imaging dose in the range of that of a clinical CBCT scanner. A spatially distributed CNT x-ray source array was designed and fabricated. It has enabled a new multisource CBCT to overcome some of the main inherent limitations of the conventional CBCT.
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Affiliation(s)
- Boyuan Li
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Christina R Inscoe
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Shuang Xu
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Timothy Capo
- Independent Consultant, United States of America
| | - Donald A Tyndall
- Division of Diagnostic Sciences, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Yueh Z Lee
- Department of Radiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Jianping Lu
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Otto Zhou
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
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Muttanahally KS, Sheppard S, Yadav S, Tadinada A. The Utility of Cone Beam Computed Tomography Scans in Diagnosing and Treating Anterior Lesions of the Maxilla and Mandible. Cureus 2024; 16:e52804. [PMID: 38389599 PMCID: PMC10883409 DOI: 10.7759/cureus.52804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2024] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND The standard screening protocol for radiographic examination in dentistry as per the American Dental Association recommendations is a panoramic radiograph (PAN) and four horizontal bitewings. PAN inherently suffers from several shortcomings like the superimposition of anatomic structures, especially of the cervical spine that obscures a significant portion of the anterior maxilla and mandible. This region has a significant amount of pathology that is not adequately imaged. Three-dimensional (3D) imaging provides circumferential information on the area of interest and adds value to the diagnosis and treatment planning of pathology, especially in the anterior maxilla and mandible. However, there is not an adequate number of well-designed studies that articulate the true value addition of 3D imaging for the evaluation of this region. OBJECTIVES The objective of this study is to evaluate the value addition of 3D imaging in diagnosing pathologies in the anterior maxilla and mandible when compared to two-dimensional PAN. MATERIALS AND METHODS A total of 25 cases that had a diagnosis of anterior pathology and had both a PAN and a cone beam computed tomography (CBCT) scan were collected for this study. An institutional review board approval to retrospectively evaluate these data was obtained. The PAN and CBCT scans were randomly evaluated by a second-year dental student, an oral and maxillofacial radiology resident in training, and a board-certified oral radiologist. The scans were evaluated using a three-point modified Likert scale, where 1 represents "not visible or clear," 2 represents "visible but not clear," and 3 represents "visible and clear." The lesions were evaluated for characteristics like lesion location, size & shape, internal contents, borders of the lesion, cortical integrity, locularity, and effect on adjacent structures like root resorption. After the evaluation was completed, a comparison of the lesion diagnosis was done with histopathology to confirm the diagnosis. The evaluators were also asked to comment on the specific feature that 3D imaging provided that added value to the case. Kappa analysis was done to evaluate inter-operator reliability. RESULTS PAN demonstrated significantly lower efficacy in identifying and diagnosing lesions. Only 56% of cases were analyzed using PAN, with 44% deemed undetectable or poorly visualized. These challenging cases necessitated CBCT scans for accurate diagnosis, which successfully diagnosed all 25 cases. The p-value of 0.0002 for PAN implies a highly significant difference from histopathology, suggesting the distinctions are not due to chance. Conversely, the p-value of 0.3273 for CBCT implies that observed differences may be random, lacking sufficient evidence to reject the null hypothesis. CBCT scans consistently outperformed PAN in visualizing various lesion characteristics, underscoring their superior diagnostic capabilities. CONCLUSIONS In this study, with a small sample size, 3D imaging provided a significant value addition to the diagnosis and treatment planning by providing additional information regarding the location, extent, internal content, and effect on adjacent structures. The practical implications for clinical settings, along with comparisons to current literature, underscore the study's distinctiveness.
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Affiliation(s)
- Kavya Shankar Muttanahally
- Oral and Maxillofacial Radiology, Department of Growth and Development, University of Nebraska Medical Center, Lincoln, USA
| | - Samantha Sheppard
- Department of General Dentistry, University of Connecticut, Farmington, USA
| | - Sumit Yadav
- Department of Growth and Development, University of Nebraska Medical Center, Lincoln, USA
| | - Aditya Tadinada
- Department of Oral and Maxillofacial Radiology, University of Connecticut, Farmington, USA
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Wang Z, Zhou H, Gu S, Xia Y, Liao H, Deng Y, Gao H. Dual-energy head cone-beam CT using a dual-layer flat-panel detector: Hybrid material decomposition and a feasibility study. Med Phys 2023; 50:6762-6778. [PMID: 37675888 DOI: 10.1002/mp.16711] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 09/08/2023] Open
Abstract
BACKGROUND Flat panel detector (FPD) based cone-beam computed tomography (CT) has made tremendous progress in the last two decades, with many new and advanced medical and industrial applications keeping emerging from diagnostic imaging and image guidance for radiotherapy and interventional surgery. The current cone-beam CT (CBCT), however, is still suboptimal for head CT scan which requires a high standard of image quality. While the dual-layer FPD technology is under extensive development and is promising to further advance CBCT from qualitative anatomic imaging to quantitative dual-energy CT, its potential of enabling head CBCT applications has not yet been fully investigated. PURPOSE The relatively moderate energy separation from the dual-layer FPD and the overall low signal level especially at the bottom-layer detector, could raise significant challenges in performing high-quality dual-energy material decomposition (MD). In this work, we propose a hybrid, physics and model guided, MD algorithm that attempts to fully use the detected x-ray signals and prior-knowledge behind head CBCT using dual-layer FPD. METHODS Firstly, a regular projection-domain MD is performed as initial results of our approach and for comparison as conventional method. Secondly, based on the combined projection, a dual-layer multi-material spectral correction (dMMSC) is applied to generate beam hardening free images. Thirdly, the dMMSC corrected projections are adopted as a physics-model based guidance to generate a hybrid MD. A set of physics experiments including fan-beam scan and cone-beam scan using a head phantom and a Gammex Multi-Energy CT phantom are conducted to validate our proposed approach. RESULTS The combined reconstruction could reduce noise by about 10% with no visible resolution degradation. The fan-beam studies on the Gammex phantom demonstrated an improved MD performance, with the averaged iodine quantification error for the 5-15 mg/ml iodine inserts reduced from about 5.6% to 3.0% by the hybrid method. On fan-beam scan of the head phantom, our proposed hybrid MD could significantly reduce the streak artifacts, with CT number nonuniformity (NU) in the selected regions of interest (ROIs) reduced from 23 Hounsfield Units (HU) to 4.2 HU, and the corresponding noise suppressed from 31 to 6.5 HU. For cone-beam scan, after scatter correction (SC) and cone-beam artifact reduction (CBAR), our approach can also significantly improve image quality, with CT number NU in the selected ROI reduced from 24.2 to 6.6 HU and the noise level suppressed from 22.1 to 8.2 HU. CONCLUSIONS Our proposed physics and model guided hybrid MD for dual-layer FPD based head CBCT can significantly improve the robustness of MD and suppress the low-signal artifact. This preliminary feasibility study also demonstrated that the dual-layer FPD is promising to enable head CBCT spectral imaging.
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Affiliation(s)
- Zhilei Wang
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China
| | - Hao Zhou
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China
| | - Shan Gu
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China
| | - Yingxian Xia
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China
| | - Haiyue Liao
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China
| | - Yifan Deng
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China
| | - Hewei Gao
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China
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Xu S, Hu Y, Li B, Inscoe CR, Tyndall DA, Lee YZ, Lu J, Zhou O. Volumetric computed tomography with carbon nanotube X-ray source array for improved image quality and accuracy. COMMUNICATIONS ENGINEERING 2023; 2:71. [PMID: 38549919 PMCID: PMC10955816 DOI: 10.1038/s44172-023-00123-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 09/28/2023] [Indexed: 08/04/2024]
Abstract
Cone beam computed tomography (CBCT) is widely used in medical and dental imaging. Compared to a multidetector CT, it provides volumetric images with high isotropic resolution at a reduced radiation dose, cost and footprint without the need for patient translation. The current CBCT has several intrinsic limitations including reduced soft tissue contrast, inaccurate quantification of X-ray attenuation, image distortions and artefacts, which have limited its clinical applications primarily to imaging hard tissues and made quantitative analysis challenging. Here we report a multisource CBCT (ms-CBCT) which overcomes the short-comings of the conventional CBCT by using multiple narrowly collimated and rapidly scanning X-ray beams from a carbon nanotube field emission source array. Phantom imaging studies show that, the ms-CBCT increases the accuracy of the Hounsfield unit values by 60%, eliminates the cone beam artefacts, extends the axial coverage, and improves the soft tissue contrast-to-noise ratio by 30-50%, compared to the CBCT configuration.
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Affiliation(s)
- Shuang Xu
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
| | - Yuanming Hu
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
| | - Boyuan Li
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
| | - Christina R. Inscoe
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
| | - Donald A. Tyndall
- Department of Diagnostic Sciences, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
| | - Yueh Z. Lee
- Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
| | - Jianping Lu
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
| | - Otto Zhou
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
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Fontes RMVQ, de Carvalho Nunes TA, dos Santos Machado RF, Ribeiro PML, Marques JAM, Corte-Real A. Reproducibility of human landmark identification in morphological mandible prototypes: major parameters for a 3D CBCT approach. Forensic Sci Res 2023; 8:211-218. [PMID: 38221974 PMCID: PMC10785591 DOI: 10.1093/fsr/owad029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 09/08/2023] [Indexed: 01/16/2024] Open
Abstract
The establishment of anthropometric measurements is of fundamental importance for the correct identification of human bodies. The objective of this study was to evaluate the accuracy and reliability of two-dimensional craniometric landmarks obtained from three-dimensional cone beam computed tomography reconstructions for forensic identification of humans. Computed tomography images with voxel sizes of 0.25, 0.3, and 0.4 mm were obtained using i-CAT® three-dimensional equipment. Ten landmarks were randomly selected, and 10 measurements were demarcated in the three-dimensional reconstruction to evaluate the mandibular condyle, ramus, and body. This study demonstrated that protocols with voxels of 0.3 mm should be preferentially indicated for the evaluation of linear and angular measurements. Implementing our methodology using prototypes for clinical and forensic simulations allows comparisons with human databases in identification issues.
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Affiliation(s)
| | - Tiago Alves de Carvalho Nunes
- Forensic Dentistry Laboratory, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas, Coimbra, Portugal
| | | | | | | | - Ana Corte-Real
- Institute of Health Sciences, Federal University of Bahia, Salvador, Bahia, Brazil
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Galecio-Castillo M, Vivanco-Suarez J, Zevallos CB, Dajles A, Weng J, Farooqui M, Ribo M, Jovin TG, Ortega-Gutierrez S. Direct to angiosuite strategy versus standard workflow triage for endovascular therapy: systematic review and meta-analysis. J Neurointerv Surg 2023; 15:e17-e25. [PMID: 35710313 DOI: 10.1136/neurintsurg-2022-018895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/23/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND Reducing stroke workflow times when performing endovascular thrombectomy is associated with improvement in clinical outcomes. We compared outcomes among large vessel occlusion (LVO) stroke patients following the direct to angiosuite (DTAS) strategy versus standard workflow (SW) when undergoing endovascular therapy. METHODS We conducted a systematic review and meta-analysis to compare rates of functional outcomes, reperfusion, symptomatic intracranial hemorrhage (sICH) and stroke workflow metrics. We included observational studies and clinical trials that compared the DTAS strategy versus SW, and at least one outcome of interest was assessed. Clinical, methodological and statistical heterogeneity were measured, and a random-effects model was used. RESULTS 12 studies were included in the systematic review and 8 in the meta-analysis (n=2890). The DTAS strategy was associated with significant higher odds of good functional outcome at 90 days (47.3% vs 34.9%; OR 1.58, 95% CI 1.16 to 2.14) and a significant average reduction of door-to-puncture (mean differences (MD) -35.09, 95% CI -49.76 to -20.41) and door-to-reperfusion times (MD -32.88, 95% CI -50.75 to -15.01). We found no differences in sICH (OR 0.80, 95% CI 0.53 to 1.20), mortality (OR 1.00, 95% CI 0.60 to 1.67) or successful reperfusion rates (OR 1.37, 95% CI 0.82 to 2.29). Moreover, the DTAS strategy was associated with greater odds of dramatic clinical improvement at 24 hours (OR 1.79, 95% CI 1.15 to 2.79). CONCLUSION Patients undergoing the DTAS strategy had a significant reduction in door-to-puncture and door-to-reperfusion times. This resulted in an increased rate of early neurological and 90-day functional recovery without compromising safety in LVO patients undergoing endovascular thrombectomy.
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Affiliation(s)
| | - Juan Vivanco-Suarez
- Neurology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Cynthia B Zevallos
- Neurology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Andres Dajles
- Neurology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Julie Weng
- Neurology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Mudassir Farooqui
- Neurology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Marc Ribo
- Stroke Unit. Neurology, Hospital Vall d'Hebron, Barcelona, Spain
- Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Tudor G Jovin
- Neurology, Cooper University Hospital, Camden, New Jersey, USA
| | - Santiago Ortega-Gutierrez
- Neurology, Neurosurgery and Radiology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
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8
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Xu S, Li B, Inscoe CR, Bastawros D, Tyndall DA, Lee YZ, Lu J, Zhou O. Evaluation of the feasibility of a multisource CBCT for maxillofacial imaging. Phys Med Biol 2023; 68:10.1088/1361-6560/acea17. [PMID: 37487498 PMCID: PMC10460191 DOI: 10.1088/1361-6560/acea17] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/24/2023] [Indexed: 07/26/2023]
Abstract
Objective. The aim of this study was to investigate the feasibility of improving the image quality and accuracy of cone beam computed tomography (CBCT) by replacing the conventional wide cone angle x-ray tube with a distributed x-ray source array positioned in the axial direction.Approach. The multisource CBCT (ms-CBCT) design was experimentally simulated using a benchtop scanner with a carbon nanotube x-ray tube and a flat-panel detector. The source was collimated and translated in the axial direction to simulate a source array with a reduced cone angle for each beam. An adjacent scatter ratio subtraction (ASRS) method was implemented for residual scatter reduction. Several phantoms were imaged using the ms-CBCT and conventional CBCT configurations under otherwise similar conditions. The Requirements of the ms-CBCT design on the x-ray source and detector were evaluated.Main results. Compared to the conventional CBCT, the ms-CBCT design with 8 sources and ASRS significantly improved the image quality and accuracy, including: (1) reducing the cupping artifact from 15% to 3.5%; (2) reducing the spatial nonuniformity of the CT Hounsfield unit values from 38.0 to 9.2; (3) improving the contrast-to-noise ratio of the low contrast objects (acrylic and low density polyethylene inserts) against the water-equivalent background by ∼20% and (4) reducing the root-mean-square error of the HU values by 70%, from 420.1 to 124.4. The imaging dose and scanning time used by the current clinical CBCT for maxillofacial imaging can be achieved by current source and detector technologies.Significance. The ms-CBCT design significantly reduces the scatter and improves the image quality and accuracy compared to the conventional CBCT.
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Affiliation(s)
- Shuang Xu
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill; Chapel Hill, NC 27599, United States of America
| | - Boyuan Li
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill; Chapel Hill, NC 27599, United States of America
| | - Christina R Inscoe
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill; Chapel Hill, NC 27599, United States of America
| | - Daniel Bastawros
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill; Chapel Hill, NC 27599, United States of America
| | - Donald A Tyndall
- Department of Diagnostic Sciences, Adams School of Dentistry, University of North Carolina at Chapel Hill; Chapel Hill, NC 27599, United States of America
| | - Yueh Z Lee
- Department of Radiology, University of North Carolina at Chapel Hill; Chapel Hill, NC 27599, United States of America
| | - Jianping Lu
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill; Chapel Hill, NC 27599, United States of America
| | - Otto Zhou
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill; Chapel Hill, NC 27599, United States of America
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Papadakis AE, Damilakis J. Assessment of abdominal organ dose and image quality in varying arc trajectory interventional C-arm cone beam CT. Phys Med 2022; 102:46-54. [PMID: 36095946 DOI: 10.1016/j.ejmp.2022.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 08/08/2022] [Accepted: 08/25/2022] [Indexed: 10/14/2022] Open
Abstract
PURPOSE The aim of this study was to investigate the effect of varying arc exposure trajectory on radiation dose to radiosensitive organs and to assess image quality in abdominal C-arm cone beam computed tomography (CBCT) interventional procedures using a latest generation system. METHODS An anthropomorphic phantom that simulates the average adult individual was used. Individual-specific Monte Carlo (MC) simulation dosimetry was performed to estimate organ doses (OD) in abdominal C-arm CBCT. Seven examination protocols prescribed by the system for vascular and soft tissue CBCT, were simulated. These protocols are differentiated in the range of the arc exposure trajectory and the level of radiation dose delivered to the patient. OD was estimated for liver, adrenals, kidneys, pancreas, stomach, gall bladder, spleen, bone and skin. Image noise, signal to noise ratio (SNR), contrast to noise ratio (CNR) and in-plane spatial resolution were assessed using CT-specific image quality assessment phantoms. RESULTS OD was found to depend on the range of arc trajectory and was higher for posterior located organs. In vascular protocols OD ranged from 4.75 mGy for skin to 0.60 mGy for bone. Image noise was higher in vascular protocols than in soft tissue ones. SNR and CNR were significantly modified among different soft tissue protocols (P < 0.05). In-plane spatial resolution was found 0.80 lp/mm in vascular as opposed to 0.41 lp/mm in soft tissue protocols. CONCLUSIONS The current results may be used to estimate OD for different examination protocols and enable operators choose the appropriate acquisition protocol on the preprogrammed interventional task.
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Affiliation(s)
- Antonios E Papadakis
- Medical Physics Department, University General Hospital of Heraklion, Stavrakia 71110, Crete, Greece.
| | - John Damilakis
- Medical Physics Department, University of Crete, Stavrakia 71110, Crete, Greece
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10
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Tan S, Xu Z. Intelligent Algorithm-Based Multislice Spiral Computed Tomography to Diagnose Coronary Heart Disease. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2022; 2022:4900803. [PMID: 35069783 PMCID: PMC8776441 DOI: 10.1155/2022/4900803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 12/11/2021] [Accepted: 12/22/2021] [Indexed: 11/18/2022]
Abstract
In this study, dictionary learning and expectation maximization reconstruction (DLEM) was combined to denoise 64-slice spiral CT images, and results of coronary angiography (CAG) were used as standard to evaluate its clinical value in diagnosing coronary artery diseases. 120 patients with coronary heart disease (CHD) confirmed by CAG examination were retrospectively selected as the research subjects. According to the random number table method, the patients were divided into two groups: the control group was diagnosed by conventional 64-slice spiral CT images, and the observation group was diagnosed by 64-slice spiral CT images based on the DLEM algorithm, with 60 cases in both groups. With CAG examination results as the standard, the diagnostic effects of the two CT examination methods were compared. The results showed that when the number of iterations of maximum likelihood expectation maximization (MLEM) algorithm reached 50, the root mean square error (RMSE) and peak signal to noise ratio (PSNR) values were similar to the results obtained by the DLEM algorithm under a number of iterations of 10 when the RMSE and PSNR values were 18.9121 dB and 74.9911 dB, respectively. In the observation group, 28.33% (17/60) images were of grade 4 or above before processing; after processing, it was 70% (42/60), significantly higher than the proportion of high image quality before processing. The overall diagnostic consistency, sensitivity, specificity, and accuracy (88.33%, 86.67%, 80%, and 85%) of the observation group were better than those in the control group (60.46%, 62.5%, 58.33%, and 61.66%). In conclusion, the DLEM algorithm has good denoising effect on 64-slice spiral CT images, which significantly improves the accuracy in the diagnosis of coronary artery stenosis and has good clinical diagnostic value and is worth promoting.
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Affiliation(s)
- Shaowen Tan
- Department of Cardiovascular Medicine, The Third Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, China
| | - Zili Xu
- Department of Cardiovascular Medicine, The Third Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, China
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Requena M, Ren Z, Ribo M. Direct Transfer to Angiosuite in Acute Stroke: Why, When, and How? Neurology 2021; 97:S34-S41. [PMID: 34785602 DOI: 10.1212/wnl.0000000000012799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/05/2021] [Indexed: 02/04/2023] Open
Abstract
Time to reperfusion is one of the strongest predictors of functional outcome in acute stroke due to a large vessel occlusion (LVO). Direct transfer to angiography suite (DTAS) protocols have shown encouraging results in reducing in-hospital delays. DTAS allows bypassing of conventional imaging in the emergency room by ruling out an intracranial hemorrhage or a large established infarct with imaging performed before transfer to the thrombectomy-capable center in the angiography suite using flat-panel CT (FP-CT). The rate of patients with stroke code primarily admitted to a comprehensive stroke center with a large ischemic established lesion is <10% within 6 hours from onset and remains <20% among patients with LVO or transferred from a primary stroke center. At the same time, stroke severity is an acceptable predictor of LVO. Therefore, ideal DTAS candidates are patients admitted in the early window with severe symptoms. The main difference between protocols adopted in different centers is the inclusion of FP-CT angiography to confirm an LVO before femoral puncture. While some centers advocate for FP-CT angiography, others favor additional time saving by directly assessing the presence of LVO with an angiogram. The latter, however, leads to unnecessary arterial punctures in patients with no LVO (3%-22% depending on selection criteria). Independently of these different imaging protocols, DTAS has been shown to be effective and safe in improving in-hospital workflow, achieving a reduction of door-to-puncture time as low as 16 minutes without safety concerns. The impact of DTAS on long-term functional outcomes varies between published studies, and randomized controlled trials are warranted to examine the benefit of DTAS.
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Affiliation(s)
- Manuel Requena
- From the Stroke Unit (M.R., M.R.), Neurology Department, Vall D'Hebron University Hospital, Barcelona, Spain; and Department of Neurosurgery (Z.R.), Cleveland Clinic Florida, Weston
| | - Zeguang Ren
- From the Stroke Unit (M.R., M.R.), Neurology Department, Vall D'Hebron University Hospital, Barcelona, Spain; and Department of Neurosurgery (Z.R.), Cleveland Clinic Florida, Weston
| | - Marc Ribo
- From the Stroke Unit (M.R., M.R.), Neurology Department, Vall D'Hebron University Hospital, Barcelona, Spain; and Department of Neurosurgery (Z.R.), Cleveland Clinic Florida, Weston.
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12
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Fahrig R, Jaffray DA, Sechopoulos I, Webster Stayman J. Flat-panel conebeam CT in the clinic: history and current state. J Med Imaging (Bellingham) 2021; 8:052115. [PMID: 34722795 DOI: 10.1117/1.jmi.8.5.052115] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/27/2021] [Indexed: 11/14/2022] Open
Abstract
Research into conebeam CT concepts began as soon as the first clinical single-slice CT scanner was conceived. Early implementations of conebeam CT in the 1980s focused on high-contrast applications where concurrent high resolution ( < 200 μ m ), for visualization of small contrast-filled vessels, bones, or teeth, was an imaging requirement that could not be met by the contemporaneous CT scanners. However, the use of nonlinear imagers, e.g., x-ray image intensifiers, limited the clinical utility of the earliest diagnostic conebeam CT systems. The development of consumer-electronics large-area displays provided a technical foundation that was leveraged in the 1990s to first produce large-area digital x-ray detectors for use in radiography and then compact flat panels suitable for high-resolution and high-frame-rate conebeam CT. In this review, we show the concurrent evolution of digital flat panel (DFP) technology and clinical conebeam CT. We give a brief summary of conebeam CT reconstruction, followed by a brief review of the correction approaches for DFP-specific artifacts. The historical development and current status of flat-panel conebeam CT in four clinical areas-breast, fixed C-arm, image-guided radiation therapy, and extremity/head-is presented. Advances in DFP technology over the past two decades have led to improved visualization of high-contrast, high-resolution clinical tasks, and image quality now approaches the soft-tissue contrast resolution that is the standard in clinical CT. Future technical developments in DFPs will enable an even broader range of clinical applications; research in the arena of flat-panel CT shows no signs of slowing down.
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Affiliation(s)
- Rebecca Fahrig
- Innovation, Advanced Therapies, Siemens Healthcare GmbH, Forchheim, Germany.,Friedrich-Alexander Universitat, Department of Computer Science 5, Erlangen, Germany
| | - David A Jaffray
- MD Anderson Cancer Center, Departments of Radiation Physics and Imaging Physics, Houston, Texas, United States
| | - Ioannis Sechopoulos
- Radboud University Medical Center, Department of Medical Imaging, Nijmegen, The Netherlands.,Dutch Expert Center for Screening (LRCB), Nijmegen, The Netherlands.,University of Twente, Technical Medical Center, Enschede, The Netherlands
| | - J Webster Stayman
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
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13
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Gong H, Tao S, Gagneur JD, Liu W, Shen J, McCollough CH, Hu Y, Leng S. Implementation and experimental evaluation of Mega-voltage fan-beam CT using a linear accelerator. Radiat Oncol 2021; 16:139. [PMID: 34321029 PMCID: PMC8317342 DOI: 10.1186/s13014-021-01862-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/19/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mega-voltage fan-beam Computed Tomography (MV-FBCT) holds potential in accurate determination of relative electron density (RED) and proton stopping power ratio (SPR) but is not widely available. OBJECTIVE To demonstrate the feasibility of MV-FBCT using a medical linear accelerator (LINAC) with a 2.5 MV imaging beam, an electronic portal imaging device (EPID) and multileaf collimators (MLCs). METHODS MLCs were used to collimate MV beam along z direction to enable a 1 cm width fan-beam. Projection data were acquired within one gantry rotation and preprocessed with in-house developed artifact correction algorithms before the reconstruction. MV-FBCT data were acquired at two dose levels: 30 and 60 monitor units (MUs). A Catphan 604 phantom was used to evaluate basic image quality. A head-sized CIRS phantom with three configurations of tissue-mimicking inserts was scanned and MV-FBCT Hounsfield unit (HU) to RED calibration was established for each insert configuration using linear regression. The determination coefficient ([Formula: see text]) was used to gauge the accuracy of HU-RED calibration. Results were compared with baseline single-energy kilo-voltage treatment planning CT (TP-CT) HU-RED calibration which represented the current standard clinical practice. RESULTS The in-house artifact correction algorithms effectively suppressed ring artifact, cupping artifact, and CT number bias in MV-FBCT. Compared to TP-CT, MV-FBCT was able to improve the prediction accuracy of the HU-RED calibration curve for all three configurations of insert materials, with [Formula: see text] > 0.9994 and [Formula: see text] < 0.9990 for MV-FBCT and TP-CT HU-RED calibration curves of soft-tissue inserts, respectively. The measured mean CT numbers of blood-iodine mixture inserts in TP-CT drastically deviated from the fitted values but not in MV-FBCT. Reducing the radiation level from 60 to 30 MU did not decrease the prediction accuracy of the MV-FBCT HU-RED calibration curve. CONCLUSION We demonstrated the feasibility of MV-FBCT and its potential in providing more accurate RED estimation.
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Affiliation(s)
- Hao Gong
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Shengzhen Tao
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Justin D Gagneur
- Department of Radiology, Mayo Clinic Arizona, 5881 East Mayo Blvd, Phoenix, AZ, 85258, USA
| | - Wei Liu
- Department of Radiology, Mayo Clinic Arizona, 5881 East Mayo Blvd, Phoenix, AZ, 85258, USA
| | - Jiajian Shen
- Department of Radiology, Mayo Clinic Arizona, 5881 East Mayo Blvd, Phoenix, AZ, 85258, USA
| | - Cynthia H McCollough
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Yanle Hu
- Department of Radiology, Mayo Clinic Arizona, 5881 East Mayo Blvd, Phoenix, AZ, 85258, USA.
| | - Shuai Leng
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
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Minnema J, van Eijnatten M, der Sarkissian H, Doyle S, Koivisto J, Wolff J, Forouzanfar T, Lucka F, Batenburg KJ. Efficient high cone-angle artifact reduction in circular cone-beam CT using deep learning with geometry-aware dimension reduction. Phys Med Biol 2021; 66. [PMID: 34107467 DOI: 10.1088/1361-6560/ac09a1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 06/09/2021] [Indexed: 11/11/2022]
Abstract
High cone-angle artifacts (HCAAs) appear frequently in circular cone-beam computed tomography (CBCT) images and can heavily affect diagnosis and treatment planning. To reduce HCAAs in CBCT scans, we propose a novel deep learning approach that reduces the three-dimensional (3D) nature of HCAAs to two-dimensional (2D) problems in an efficient way. Specifically, we exploit the relationship between HCAAs and the rotational scanning geometry by training a convolutional neural network (CNN) using image slices that were radially sampled from CBCT scans. We evaluated this novel approach using a dataset of input CBCT scans affected by HCAAs and high-quality artifact-free target CBCT scans. Two different CNN architectures were employed, namely U-Net and a mixed-scale dense CNN (MS-D Net). The artifact reduction performance of the proposed approach was compared to that of a Cartesian slice-based artifact reduction deep learning approach in which a CNN was trained to remove the HCAAs from Cartesian slices. In addition, all processed CBCT scans were segmented to investigate the impact of HCAAs reduction on the quality of CBCT image segmentation. We demonstrate that the proposed deep learning approach with geometry-aware dimension reduction greatly reduces HCAAs in CBCT scans and outperforms the Cartesian slice-based deep learning approach. Moreover, the proposed artifact reduction approach markedly improves the accuracy of the subsequent segmentation task compared to the Cartesian slice-based workflow.
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Affiliation(s)
- Jordi Minnema
- Amsterdam UMC and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, Department of Oral and Maxillofacial Surgery/Pathology, 3D Innovationlab, Amsterdam Movement Sciences, 1081 HV Amsterdam, The Netherlands
| | - Maureen van Eijnatten
- Medical Image Analysis Group, Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands.,Centrum Wiskunde & Informatica (CWI), 1090 GB Amsterdam, The Netherlands
| | | | - Shannon Doyle
- Centrum Wiskunde & Informatica (CWI), 1090 GB Amsterdam, The Netherlands
| | - Juha Koivisto
- Department of Physics, University of Helsinki, Gustaf Hällsströmin katu 2, FI-00560, Helsinki, Finland
| | - Jan Wolff
- Department of Oral and Maxillofacial Surgery, Division for Regenerative Orofacial Medicine, University Hospital Hamburg-Eppendorf, D-20246 Hamburg, Germany.,Fraunhofer Research Institution for Additive Manufacturing Technologies IAPT, Am Schleusengraben 13, D-21029 Hamburg, Germany.,Department of Dentistry and Oral Health, Aarhus University, Vennelyst Boulevard 9, DK-8000 Aarhus C, Denmark
| | - Tymour Forouzanfar
- Amsterdam UMC and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, Department of Oral and Maxillofacial Surgery/Pathology, 3D Innovationlab, Amsterdam Movement Sciences, 1081 HV Amsterdam, The Netherlands
| | - Felix Lucka
- Centrum Wiskunde & Informatica (CWI), 1090 GB Amsterdam, The Netherlands.,Centre for Medical Image Computing, University College London, WC1E 6BT London, United Kingdom
| | - Kees Joost Batenburg
- Centrum Wiskunde & Informatica (CWI), 1090 GB Amsterdam, The Netherlands.,Leiden Institute of Advanced Computer Science (LIACS), Leiden University, 2333 CA Leiden, The Netherlands
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15
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Sisniega A, Stayman JW, Capostagno S, Weiss CR, Ehtiati T, Siewerdsen JH. Accelerated 3D image reconstruction with a morphological pyramid and noise-power convergence criterion. Phys Med Biol 2021; 66:055012. [PMID: 33477131 DOI: 10.1088/1361-6560/abde97] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Model-based iterative reconstruction (MBIR) for cone-beam CT (CBCT) offers better noise-resolution tradeoff and image quality than analytical methods for acquisition protocols with low x-ray dose or limited data, but with increased computational burden that poses a drawback to routine application in clinical scenarios. This work develops a comprehensive framework for acceleration of MBIR in the form of penalized weighted least squares optimized with ordered subsets separable quadratic surrogates. The optimization was scheduled on a set of stages forming a morphological pyramid varying in voxel size. Transition between stages was controlled with a convergence criterion based on the deviation between the mid-band noise power spectrum (NPS) measured on a homogeneous region of the evolving reconstruction and that expected for the converged image, computed with an analytical model that used projection data and the reconstruction parameters. A stochastic backprojector was developed by introducing a random perturbation to the sampling position of each voxel for each ray in the reconstruction within a voxel-based backprojector, breaking the deterministic pattern of sampling artifacts when combined with an unmatched Siddon forward projector. This fast, forward and backprojector pair were included into a multi-resolution reconstruction strategy to provide support for objects partially outside of the field of view. Acceleration from ordered subsets was combined with momentum accumulation stabilized with an adaptive technique that automatically resets the accumulated momentum when it diverges noticeably from the current iteration update. The framework was evaluated with CBCT data of a realistic abdomen phantom acquired on an imaging x-ray bench and with clinical CBCT data from an angiography robotic C-arm (Artis Zeego, Siemens Healthineers, Forchheim, Germany) acquired during a liver embolization procedure. Image fidelity was assessed with the structural similarity index (SSIM) computed with a converged reconstruction. The accelerated framework provided accurate reconstructions in 60 s (SSIM = 0.97) and as little as 27 s (SSIM = 0.94) for soft-tissue evaluation. The use of simple forward and backprojectors resulted in 9.3× acceleration. Accumulation of momentum provided extra ∼3.5× acceleration with stable convergence for 6-30 subsets. The NPS-driven morphological pyramid resulted in initial faster convergence, achieving similar SSIM with 1.5× lower runtime than the single-stage optimization. Acceleration of MBIR to provide reconstruction time compatible with clinical applications is feasible via architectures that integrate algorithmic acceleration with approaches to provide stable convergence, and optimization schedules that maximize convergence speed.
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Affiliation(s)
- A Sisniega
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD United States of America
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16
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Peltonen JI, Kaasalainen T, Kortesniemi M. Metal artifacts in intraoperative O-arm CBCT scans. BMC Med Imaging 2021; 21:2. [PMID: 33407232 PMCID: PMC7789607 DOI: 10.1186/s12880-020-00538-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 12/14/2020] [Indexed: 08/23/2023] Open
Abstract
Background Cone-beam computed tomography (CBCT) has become an increasingly important medical imaging modality in orthopedic operating rooms. Metal implants and related image artifacts create challenges for image quality optimization in CBCT. The purpose of this study was to develop a robust and quantitative method for the comprehensive determination of metal artifacts in novel CBCT applications. Methods The image quality of an O-arm CBCT device was assessed with an anthropomorphic pelvis phantom in the presence of metal implants. Three different kilovoltage and two different exposure settings were used to scan the phantom both with and without the presence of metal rods. Results The amount of metal artifact was related to the applied CBCT imaging protocol parameters. The size of the artifact was moderate with all imaging settings. The highest applied kilovoltage and exposure level distinctly increased artifact severity. Conclusions The developed method offers a practical and robust way to quantify metal artifacts in CBCT. Changes in imaging parameters may have nonlinear effects on image quality which are not anticipated based on physics.
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Affiliation(s)
- Juha I Peltonen
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, 00029, Helsinki, Finland.
| | - Touko Kaasalainen
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, 00029, Helsinki, Finland
| | - Mika Kortesniemi
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, 00029, Helsinki, Finland
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Tashima H, Yoshida E, Wakizaka H, Takahashi M, Nagatsu K, Tsuji AB, Kamada K, Parodi K, Yamaya T. 3D Compton image reconstruction method for whole gamma imaging. Phys Med Biol 2020; 65:225038. [PMID: 32937613 DOI: 10.1088/1361-6560/abb92e] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Compton imaging or Compton camera imaging has been studied well, but its advantages in nuclear medicine and molecular imaging have not been demonstrated yet. Therefore, the aim of this work was to compare Compton imaging with positron emission tomography (PET) by using the same imaging platform of whole gamma imaging (WGI). WGI is a concept that combines PET with Compton imaging by inserting a scatterer ring into a PET ring. This concept utilizes diverse types of gamma rays for 3D tomographic imaging. In this paper, we remodeled our previous WGI prototype for small animal imaging, and we developed an image reconstruction method based on a list-mode ordered subset expectation maximization algorithm incorporating detector response function modeling, random correction and normalization (sensitivity correction) for either PET and Compton imaging. To the best of our knowledge, this is the world's first realization of a full-ring Compton imaging system. We selected 89Zr as an imaging target because a 89Zr nuclide emits a 909 keV single-gamma ray as well as a positron, and we can directly compare Compton imaging of 909 keV photons with PET, a well-established modality. We measured a cylindrical phantom and a small rod phantom filled with 89Zr solutions of 10.3 MBq and 10.2 MBq activity, respectively, for 1 h each. The uniform radioactivity distribution of the cylindrical phantom was reconstructed with normalization in both PET and Compton imaging. Coefficients of variation for region-of-interest values were 4.2% for Compton imaging and 3.3% for PET; the difference might be explained by the difference in the detected count number. The small rod phantom experiment showed that the WGI Compton imaging had spatial resolution better than 3.0 mm at the peripheral region although the center region had lower resolution. PET resolved 2.2 mm rods clearly at any location. We measured a mouse for 1 h, 1 d after injection of 9.8 MBq 89Zr oxalate. The 89Zr assimilated in the mouse bony structures was clearly depicted, and Compton imaging results agreed well with PET images, especially for the region inside the scatterer ring. In conclusion, we demonstrated the performance of WGI using the developed Compton image reconstruction method. We realized Compton imaging with a quality approaching that of PET, which is supporting a future expectation that Compton imaging outperforms PET.
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Affiliation(s)
- Hideaki Tashima
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
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18
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Mao WY, Lei J, Lim LZ, Gao Y, Tyndall DA, Fu K. Comparison of radiographical characteristics and diagnostic accuracy of intraosseous jaw lesions on panoramic radiographs and CBCT. Dentomaxillofac Radiol 2020; 50:20200165. [PMID: 32941743 DOI: 10.1259/dmfr.20200165] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE To investigate the differences in imaging characteristics and the diagnostic accuracy of 225 intraosseous jaw lesions on panoramic radiographs (PAN) versus cone beam computed tomography (CBCT). METHODS 225 sets of PAN and CBCT images with biopsy-proven histopathological diagnoses were retrospectively compared in terms of radiographic features and diagnostic accuracy. The imaging characteristics of PAN and CBCT were independently evaluated by two oral and maxillofacial radiologists who were required to answer 12 questions and provided up to three differential diagnoses with their confidence scores. RESULTS Odds ratios (ORs) were statistically significant for border cortication (OR = 1.521; p = .003) and border continuity (OR = 0.421; p = .001), involvement on neurovascular canals (OR = 2.424; p < .001), expansion (OR = 7.948; p < .001), cortical thinning (OR = 20.480; p < .001) as well as its destruction (OR = 25.022; p < .001) and root resorption (OR = 2.477; p < .001). Furthermore, imaging features in the posterior and mandibular regions showed better agreement than those in the anterior and maxillary regions, respectively. The diagnostic accuracy of the first differential diagnosis was higher on CBCT than on PAN (Observer 1:78.7 vs 64.4%; Observer 2: 78.7 vs 70.2% (p < .001)). The observers' confidence scores were also higher at CBCT interpretation compared with PAN. CONCLUSIONS CBCT demonstrated a greater number of imaging characteristics of intraosseous jaw lesions compared with PAN, especially in the anterior regions of both jaws and in the maxilla. Diagnostic accuracy is improved with CBCT compared to PAN, especially for lesions in the maxilla. Radiologists have greater confidence when using CBCT.
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Affiliation(s)
- Wei-Yu Mao
- Department of Oral & Maxillofacial Radiology, Peking University School & Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Jie Lei
- Department of Oral & Maxillofacial Radiology, Peking University School & Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Li Zhen Lim
- Discipline of Oral & Maxillofacial Surgery, Faculty of Dentistry, National University of Singapore, Singapore, Singapore.,Department of Diagnostic Sciences, University of North Carolina at Chapel Hill Adams School of Dentistry, Chapel Hill, NC, USA
| | - Yan Gao
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Beijing, China.,Department of Oral Pathology, Peking University School & Hospital of Stomatology, Beijing, China
| | - Donald A Tyndall
- Department of Diagnostic Sciences, University of North Carolina at Chapel Hill Adams School of Dentistry, Chapel Hill, NC, USA
| | - Kaiyuan Fu
- Department of Oral & Maxillofacial Radiology, Peking University School & Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Beijing, China
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