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Kalchiem-Dekel O, Bergemann R, Ma X, Christos PJ, Miodownik D, Gao Y, Mahmood U, Adusumilli PS, Bott MJ, Dycoco J, Gelblum DY, Lee RP, Park BJ, Rocco G, Solomon SB, Jones DR, Chawla M, Husta BC. Determinants of radiation exposure during mobile cone-beam CT-guided robotic-assisted bronchoscopy. Respirology 2024. [PMID: 38806394 DOI: 10.1111/resp.14765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 05/12/2024] [Indexed: 05/30/2024]
Abstract
BACKGROUND AND OBJECTIVE Robotic-assisted bronchoscopy (RAB) is an emerging modality to sample pulmonary lesions. Cone-beam computed tomography (CBCT) can be incorporated into RAB. We investigated the magnitude and predictors of patient and staff radiation exposure during mobile CBCT-guided shape-sensing RAB. METHODS Patient radiation dose was estimated by cumulative dose area product (cDAP) and cumulative reference air kerma (cRAK). Staff equivalent dose was calculated based on isokerma maps and a phantom simulation. Patient, lesion and procedure-related factors associated with higher radiation doses were identified by logistic regression models. RESULTS A total of 198 RAB cases were included in the analysis. The median patient cDAP and cRAK were 10.86 Gy cm2 (IQR: 4.62-20.84) and 76.20 mGy (IQR: 38.96-148.38), respectively. Among staff members, the bronchoscopist was exposed to the highest median equivalent dose of 1.48 μSv (IQR: 0.85-2.69). Both patient and staff radiation doses increased with the number of CBCT spins and targeted lesions (p < 0.001 for all comparisons). Patient obesity, negative bronchus sign, lesion size <2.0 cm and inadequate sampling by on-site evaluation were associated with a higher patient dose, while patient obesity and inadequate sampling by on-site evaluation were associated with a higher bronchoscopist equivalent dose. CONCLUSION The magnitude of patient and staff radiation exposure during CBCT-RAB is aligned with safety thresholds recommended by regulatory authorities. Factors associated with a higher radiation exposure during CBCT-RAB can be identified pre-operatively and solicit procedural optimization by reinforcing radiation protective measures. Future studies are needed to confirm these findings across multiple institutions and practices.
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Affiliation(s)
- Or Kalchiem-Dekel
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Reza Bergemann
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Xiaoyue Ma
- Division of Biostatistics and Epidemiology, Weill Cornell School of Medicine, New York, New York, USA
| | - Paul J Christos
- Division of Biostatistics and Epidemiology, Weill Cornell School of Medicine, New York, New York, USA
| | - Daniel Miodownik
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Yiming Gao
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Usman Mahmood
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Prasad S Adusumilli
- Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Matthew J Bott
- Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Joseph Dycoco
- Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Daphna Y Gelblum
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Robert P Lee
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Bernard J Park
- Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Gaetano Rocco
- Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Stephen B Solomon
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - David R Jones
- Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Mohit Chawla
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Bryan C Husta
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
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Ma YQ, Reynolds T, Ehtiati T, Weiss C, Hong K, Theodore N, Gang GJ, Stayman JW. Fully automatic online geometric calibration for non-circular cone-beam CT orbits using fiducials with unknown placement. Med Phys 2024; 51:3245-3264. [PMID: 38573172 DOI: 10.1002/mp.17041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND Cone-beam CT (CBCT) with non-circular scanning orbits can improve image quality for 3D intraoperative image guidance. However, geometric calibration of such scans can be challenging. Existing methods typically require a prior image, specialized phantoms, presumed repeatable orbits, or long computation time. PURPOSE We propose a novel fully automatic online geometric calibration algorithm that does not require prior knowledge of fiducial configuration. The algorithm is fast, accurate, and can accommodate arbitrary scanning orbits and fiducial configurations. METHODS The algorithm uses an automatic initialization process to eliminate human intervention in fiducial localization and an iterative refinement process to ensure robustness and accuracy. We provide a detailed explanation and implementation of the proposed algorithm. Physical experiments on a lab test bench and a clinical robotic C-arm scanner were conducted to evaluate spatial resolution performance and robustness under realistic constraints. RESULTS Qualitative and quantitative results from the physical experiments demonstrate high accuracy, efficiency, and robustness of the proposed method. The spatial resolution performance matched that of our existing benchmark method, which used a 3D-2D registration-based geometric calibration algorithm. CONCLUSIONS We have demonstrated an automatic online geometric calibration method that delivers high spatial resolution and robustness performance. This methodology enables arbitrary scan trajectories and should facilitate translation of such acquisition methods in a clinical setting.
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Affiliation(s)
- Yiqun Q Ma
- Johns Hopkins University, Baltimore, Maryland, USA
| | - Tess Reynolds
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | | | | | - Kelvin Hong
- Johns Hopkins University, Baltimore, Maryland, USA
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Niu T, Xu L, Ren Q, Gao Y, Luo C, Teng Z, Du J, Ding M, Xie J, Han H, Jiang Y. UBES: Unified scatter correction using ultrafast Boltzmann equation solver for conebeam CT. Comput Biol Med 2024; 170:108045. [PMID: 38325213 DOI: 10.1016/j.compbiomed.2024.108045] [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: 12/06/2023] [Revised: 01/10/2024] [Accepted: 01/26/2024] [Indexed: 02/09/2024]
Abstract
A semi-analytical solution to the unified Boltzmann equation is constructed to exactly describe the scatter distribution on a flat-panel detector for high-quality conebeam CT (CBCT) imaging. The solver consists of three parts, including the phase space distribution estimator, the effective source constructor and the detector signal extractor. Instead of the tedious Monte Carlo solution, the derived Boltzmann equation solver achieves ultrafast computational capability for scatter signal estimation by combining direct analytical derivation and time-efficient one-dimensional numerical integration over the trajectory along each momentum of the photon phase space distribution. The execution of scatter estimation using the proposed ultrafast Boltzmann equation solver (UBES) for a single projection is finalized in around 0.4 seconds. We compare the performance of the proposed method with the state-of-the-art schemes, including a time-expensive Monte Carlo (MC) method and a conventional kernel-based algorithm using the same dataset, which is acquired from the CBCT scans of a head phantom and an abdominal patient. The evaluation results demonstrate that the proposed UBES method achieves comparable correction accuracy compared with the MC method, while exhibits significant improvements in image quality over learning and kernel-based methods. With the advantages of MC equivalent quality and superfast computational efficiency, the UBES method has the potential to become a standard solution to scatter correction in high-quality CBCT reconstruction.
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Affiliation(s)
- Tianye Niu
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, Guangdong, China; Peking University Aerospace School of Clinical Medicine, Aerospace Center Hospital, Beijing, China.
| | - Lei Xu
- Department of Radiation Oncology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Qing Ren
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, Guangdong, China
| | - Yajuan Gao
- Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Chen Luo
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, Guangdong, China; School of Automation, Zhejiang Institute of Mechanical & Electrical Engineering, Hangzhou, Zhejiang, China
| | - Ze Teng
- Department of Radiology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jichen Du
- Peking University Aerospace School of Clinical Medicine, Aerospace Center Hospital, Beijing, China
| | - Mingchao Ding
- Peking University Aerospace School of Clinical Medicine, Aerospace Center Hospital, Beijing, China
| | - Jiayi Xie
- Peking University Third Hospital, Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Beijing, China; Department of Automatic, Tsinghua University, Beijing, China
| | - Hongbin Han
- Department of Radiology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China
| | - Yin Jiang
- Physics Department, Beihang University, Beijing, China
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Ali SO, Castellani C, Benn BS. Transbronchial Lung Cryobiopsy Performed with Cone Beam Computed Tomography Guidance Versus Fluoroscopy: A Retrospective Cohort Review. Lung 2024; 202:73-81. [PMID: 38129333 DOI: 10.1007/s00408-023-00663-1] [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: 09/27/2023] [Accepted: 11/19/2023] [Indexed: 12/23/2023]
Abstract
PURPOSE Determining the cause of interstitial lung disease (ILD) remains challenging. While surgical lung biopsy remains the gold standard approach, risks associated with it may be prohibitive. Transbronchial lung cryobiopsy (TBLC) is a minimally invasive alternative with an improved safety profile and acceptable diagnostic accuracy. We retrospectively assessed whether the use of Cone Beam computed tomography guidance for TBLC (TBLC-CBCT) improves safety and diagnostic yield compared to performing TBLC with fluoroscopic guidance (TBLC-F). METHODS A retrospective cohort review of 120 patients presenting for evaluation of newly diagnosed ILD was performed. Demographic data, pulmonary function test values, chest imaging pattern, procedural information, and final multidisciplinary discussion (MDD) diagnosis were recorded. RESULTS 62 patients underwent TBLC-F and 58 underwent TBLC-CBCT. Patients undergoing TBLC-CBCT were older (67.86 ± 10.97 vs 61.45 ± 12.77 years, p = 0.004) and had a higher forced vital capacity percent predicted (73.80 ± 17.32% vs 66.00 ± 17.45%, p = 0.03) compared to the TBLC-F group. The average probe-to-pleura distance was 5.1 ± 2.3 mm in the TBLC-CBCT group with 4.0 ± 0.3 CBCT spins performed. Pneumothorax occurred more often in the TBLC-F group (n = 6, 9.7%) compared to the TBLC-CBCT group (n = 1, 1.7%, p = 0.06). Grade 2 bleeding only occurred in the TBLC-F group (n = 4, 6.5%). A final MDD diagnosis was obtained in 89% (n = 57) of TBLC-F patients and 95% (n = 57) of TBLC-CBCT patients. CONCLUSIONS TBLC-CBCT appears to be safer compared to TBLC-F with both approaches facilitating an MDD diagnosis. Further studies from multiple institutions randomizing patients to each modality are needed to confirm these findings.
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Affiliation(s)
- Syed O Ali
- School of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Carson Castellani
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Bryan S Benn
- Division of Pulmonary and Critical Care, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
- Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
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Moon S, Kang J, Kim Y, Jo E, Jeong P, Roh Y, Baek J. Carbon nanotube-based multiple source C-arm CT system: feasibility study with prototype system. OPTICS EXPRESS 2023; 31:44772-44797. [PMID: 38178538 DOI: 10.1364/oe.503421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 12/07/2023] [Indexed: 01/06/2024]
Abstract
To extend the field of view while reducing dimensions of the C-arm, we propose a carbon nanotube (CNT)-based C-arm computed tomography (CT) system with multiple X-ray sources. A prototype system was developed using three CNT X-ray sources, enabling a feasibility study. Geometry calibration and image reconstruction were performed to improve the quality of image acquisition. However, the geometry of the prototype system led to projection truncation for each source and an overlap region of object area covered by each source in the two-dimensional Radon space, necessitating specific corrective measures. We addressed these problems by implementing truncation correction and applying weighting techniques to the overlap region during the image reconstruction phase. Furthermore, to enable image reconstruction with a scan angle less than 360°, we designed a weighting function to solve data redundancy caused by the short scan angle. The accuracy of the geometry calibration method was evaluated via computer simulations. We also quantified the improvements in reconstructed image quality using mean-squared error and structural similarity. Moreover, detector lag correction was applied to address the afterglow observed in the experimental data obtained from the prototype system. Our evaluation of image quality involved comparing reconstructed images obtained with and without incorporating the geometry calibration results and images with and without lag correction. The outcomes of our simulation study and experimental investigation demonstrated the efficacy of our proposed geometry calibration, image reconstruction method, and lag correction in reducing image artifacts.
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Verhoeven RLJ, Kops SEP, Wijma IN, Ter Woerds DKM, van der Heijden EHFM. Cone-beam CT in lung biopsy: a clinical practice review on lessons learned and future perspectives. ANNALS OF TRANSLATIONAL MEDICINE 2023; 11:361. [PMID: 37675336 PMCID: PMC10477635 DOI: 10.21037/atm-22-2845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/03/2022] [Indexed: 09/08/2023]
Abstract
Pulmonary nodules with intermediate to high risk of malignancy should preferably be diagnosed with image guide minimally invasive diagnostics before treatment. Several technological innovations have been developed to endobronchially navigate to these lesions and obtain tissue for diagnosis. This review addresses these technological advancements in navigation bronchoscopy in three basic steps: navigation, position confirmation and acquisition, with a specific focus on cone-beam computed tomography (CBCT). For navigation purposes ultrathin bronchoscopy combined with virtual bronchoscopy navigation, electromagnetic navigation and robotic assisted bronchoscopy all achieve good results as a navigation guidance tool, but cannot confirm location or guide biopsy positioning. Diagnostic yield has seen improvement by combining these techniques with a secondary imaging tool like radial endobronchial ultrasound (rEBUS) and fluoroscopy. For confirmation of lesion access, rEBUS provides local detailed ultrasound-imaging and can be used to confirm lesion access in combination with fluoroscopy, measure nodule-contact area length and determine catheter position for sampling. CBCT is the only technology that can provide precise 3D positioning confirmation. When focusing on tissue acquisition, there is often more than 10% difference between reaching the target and getting a diagnosis. This discrepancy is multifactorial and caused by breathing movements, small samples sizes, instrument tip displacements by tool rigidity and tumour inhomogeneity. Yield can be improved by targeting fluorodeoxyglucose (FDG)-avid regions, immediate feedback of rapid onsite evaluation, choosing sampling tools with different passive stiffnesses, by increasing the number biopsies taken and (future) catheter modifications like (robotic assisted-) active steering. CBCT with augmented fluoroscopy (CBCT-AF) based navigation bronchoscopy combines navigation guidance with 3D-image confirmation of instrument-in-lesion positioning in one device. CBCT-AF allows for overlaying the lesion and navigation pathway and the possibility to outline trans-parenchymal pathways. It can help guide and verify sampling in 3D in near real-time. Disadvantages are the learning curve, the inherent use of radiation and limited availability/access to hybrid theatres. A mobile C-arm can provide 3D imaging, but lower image quality due to lower power and lower contrast-to-noise ratio is a limiting factor. In conclusion, a multi-modality approach in experienced hands seems the best option for achieving a diagnostic accuracy >85%. Either adequate case selection or detailed 3D imaging are essential to obtain high accuracy. For current and future transbronchial treatments, high-resolution (CBCT) 3D-imaging is essential.
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Affiliation(s)
- Roel L J Verhoeven
- Department of Pulmonary Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Stephan E P Kops
- Department of Pulmonary Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Inge N Wijma
- Department of Pulmonary Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Desi K M Ter Woerds
- Department of Pulmonary Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
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Karius A, Szkitsak J, Strnad V, Fietkau R, Bert C. Cone-beam CT imaging with laterally enlarged field of view based on independently movable source and detector. Med Phys 2023; 50:5135-5149. [PMID: 37194354 DOI: 10.1002/mp.16463] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/03/2023] [Accepted: 05/01/2023] [Indexed: 05/18/2023] Open
Abstract
BACKGROUND CBCT imaging with field of views (FOVs) exceeding the size of scans acquired in the conventional imaging geometry, i.e. with opposing source and detector, is of high clinical importance for many medical fields. A novel approach for enlarged FOV scanning with one full-scan (EnFOV360) or two short-scans (EnFOV180) using an O-arm system arises from non-isocentric imaging based on independent source and detector rotations. PURPOSE The presentation, description, and experimental validation of this novel approach and the novel scanning techniques EnFOV360 and EnFOV180 for an O-arm system forms the scope of this work. METHODS We describe the EnFOV360, EnFOV180, and non-isocentric imaging techniques for the acquisition of laterally extended FOVs. For their experimental validation, scans of dedicated quality assurance as well as anthropomorphic phantoms were acquired, with the phantoms being placed both within the tomographic plane and at the longitudinal FOV border with and without lateral shifts from the gantry center. Based on this, geometric accuracy, contrast-noise-ratio (CNR) of different materials, spatial resolution, noise characteristics, as well as CT number profiles were quantitatively assessed. Results were compared to scans performed with the conventional imaging geometry. RESULTS With EnFOV360 and EnFOV180, we increased the in-plane size of acquired FOVs from 250 × 250 mm2 obtained for the conventional imaging geometry to up to 400 × 400 mm2 for the performed measurements. Geometric accuracy was very high for all scanning techniques with mean values ≤0.21 ± 0.11 mm. CNR and spatial resolution were comparable between isocentric and non-isocentric full-scans as well as EnFOV360, whereas substantial image quality deteriorations in this respect were observed for EnFOV180. Image noise in the isocenter was lowest for conventional full-scans with 13.4 ± 0.2 HU. For laterally shifted phantom positions, noise increased for conventional scans and EnFOV360, whereas noise reductions were observed for EnFOV180. Considering the anthropomorphic phantom scans, both EnFOV360 and EnFOV180 were comparable to conventional full-scans. CONCLUSION Both enlarged FOV techniques have high potential for imaging laterally extended FOVs. EnFOV360 revealed an image quality comparable to conventional full-scans in general. EnFOV180 showed an inferior performance particularly regarding CNR and spatial resolution.
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Affiliation(s)
- Andre Karius
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Juliane Szkitsak
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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Treb K, Ji X, Feng M, Zhang R, Periyasamy S, Laeseke PF, Dingle AM, Brace CL, Li K. A C-arm photon counting CT prototype with volumetric coverage using multi-sweep step-and-shoot acquisitions. Phys Med Biol 2022; 67:10.1088/1361-6560/ac950d. [PMID: 36162399 PMCID: PMC9623602 DOI: 10.1088/1361-6560/ac950d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/26/2022] [Indexed: 11/12/2022]
Abstract
Objective.Existing clinical C-arm interventional systems use scintillator-based energy-integrating flat panel detectors (FPDs) to generate cone-beam CT (CBCT) images. Despite its volumetric coverage, FPD-CBCT does not provide sufficient low-contrast detectability desired for certain interventional procedures. The purpose of this work was to develop a C-arm photon counting detector (PCD) CT system with a step-and-shoot data acquisition method to further improve the tomographic imaging performance of interventional systems.Approach.As a proof-of-concept, a cadmium telluride-based 51 cm × 0.6 cm PCD was mounted in front of a FPD in an Artis Zee biplane system. A total of 10 C-arm sweeps (5 forward and 5 backward) were prescribed. A motorized patient table prototype was synchronized with the C-arm system such that it translates the object by a designated distance during the sub-second rest time in between gantry sweeps. To evaluate whether this multi-sweep step-and-shoot acquisition strategy can generate high-quality and volumetric PCD-CT images without geometric distortion artifacts, experiments were performed using physical phantoms, a human cadaver head, and anin vivoswine subject. Comparison with FPD-CT was made under matched narrow beam collimation and radiation dose conditions.Main results.Compared with FPD-CT images, PCD-CT images had lower noise and improved visualization of low-contrast lesion models, as well as improved visibility of small iodinated blood vessels. Fine structures were visualized more clearly by the PCD-CT than the highest-available resolution provided by FPD-CBCT and MDCT. No perceivable geometric distortion artifacts were observed in the multi-planar PCD-CT images.Significance.This work is the first demonstration of the feasibility of high-quality and multi-planar (volumetric) PCD-CT imaging with a rotating C-arm gantry.
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Affiliation(s)
- Kevin Treb
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Xu Ji
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Mang Feng
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Ran Zhang
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Sarvesh Periyasamy
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI 53792, USA
| | - Paul F. Laeseke
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI 53792, USA
| | - Aaron M. Dingle
- Department of Surgery, School of Medicine and Public Health, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI 53792, USA
| | - Christopher L. Brace
- Department of Biomedical Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI, 53706, USA
| | - Ke Li
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI 53792, USA
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Jiang Y, Zhang Y, Luo C, Yang P, Wang J, Liang X, Zhao W, Li R, Niu T. A generalized image quality improvement strategy of cone-beam CT using multiple spectral CT labels in Pix2pix GAN. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac6bda] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 04/29/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. The quantitative and routine imaging capabilities of cone-beam CT (CBCT) are hindered from clinical applications due to the severe shading artifacts of scatter contamination. The scatter correction methods proposed in the literature only consider the anatomy of the scanned objects while disregarding the impact of incident x-ray energy spectra. The multiple-spectral model is in urgent need for CBCT scatter estimation. Approach. In this work, we incorporate the multiple spectral diagnostic multidetector CT labels into the pixel-to-pixel (Pix2pix) GAN to estimate accurate scatter distributions from CBCT projections acquired at various imaging volume sizes and x-ray energy spectra. The Pix2pix GAN combines the residual network as the generator and the PatchGAN as the discriminator to construct the correspondence between the scatter-contaminated projection and scatter distribution. The network architectures and loss function of Pix2pix GAN are optimized to achieve the best performance on projection-to-scatter transition. Results. The CBCT data of a head phantom and abdominal patients are applied to test the performance of the proposed method. The error of the corrected CBCT image using the proposed method is reduced from over 200 HU to be around 20 HU in both phantom and patient studies. The mean structural similarity index of the CT image is improved from 0.2 to around 0.9 after scatter correction using the proposed method compared with the MC-simulation method, which indicates a high similarity of the anatomy in the images before and after the proposed correction. The proposed method achieves higher accuracy of scatter estimation than using the Pix2pix GAN with the U-net generator. Significance. The proposed scheme is an effective solution to the multiple spectral CBCT scatter correction. The scatter-correction software using the proposed model will be available at: https://github.com/YangkangJiang/Cone-beam-CT-scatter-correction-tool.
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Karius A, Bert C. QAMaster: A new software framework for phantom-based computed tomography quality assurance. J Appl Clin Med Phys 2022; 23:e13588. [PMID: 35297569 PMCID: PMC8992959 DOI: 10.1002/acm2.13588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 09/04/2021] [Accepted: 02/28/2022] [Indexed: 11/06/2022] Open
Abstract
The regular evaluation of imaging performance of computed tomography (CT) scanners is essential for CT quality assurance. For automation of this process, the software QAMaster was developed at the Universitätsklinikum Erlangen, which provides based on CT scans of the CatPhan® 504 (The Phantom Laboratory, Salem, USA) automated image quality analysis and documentation by evaluating CT number accuracy, spatial linearity, uniformity, contrast-noise-ratio, spatial resolution, noise, and slice thickness. Dose assessment is supported by calculations of the weighted computed tomography dose index (CTDIw ) and weighted cone beam dose index (CBDIw ). QAMaster was tested with CatPhan® 504 scans and compared to manual evaluations of these scans, whereby high consistency of the respective results was observed. The CT numbers, spatial linearity, uniformity, contrast-noise-ratio, noise, and slice thickness deviated by only (0.13 ± 0.25) HU, (0.02 ± 0.05) mm, (-0.01 ± 0.03)%, 0.8 ± 1.8, (0.131 ± 0.05) HU, and (0.004 ± 0.005) mm between both evaluations, respectively. The QAMaster results for spatial resolution did not differ significantly (p = 0.34) from the CatPhan® 504 based manual resolution assessment. Dose computations were fully consistent between QAMaster and manual calculations. Thus, QAMaster proved to be a comprehensive and functional software for performing an automated CT quality assurance routine. QAMaster will be open-source after its release.
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Affiliation(s)
- Andre Karius
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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11
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Karius A, Strnad V, Lotter M, Kreppner S, Bert C. First clinical experience with a novel, mobile cone-beam CT system for treatment quality assurance in brachytherapy. Strahlenther Onkol 2022; 198:573-581. [PMID: 35278094 PMCID: PMC9165284 DOI: 10.1007/s00066-022-01912-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/16/2022] [Indexed: 11/04/2022]
Abstract
Background and purpose On-site cone-beam computed tomography (CBCT) has gained in importance in adaptive brachytherapy during recent years. Besides treatment planning, there is increased need particularly for image-guidance during interventional procedures and for image-guided treatment quality assurance (QA). For this purpose, an innovative CBCT device was rolled out at our hospital as the first site worldwide. We present the first clinical images and experiences. Materials and methods The novel CBCT system is constructed of a 121 cm diameter ring gantry, and features a 43.2 × 43.2 cm2 flat-panel detector, wireless remote-control via tablet-PC, and battery-powered maneuverability. Within the first months of clinical operation, we performed CBCT-based treatment QA for a total of 26 patients (8 with breast, 16 with cervix, and 2 with vaginal cancer). CBCT scans were analyzed regarding potential movements of implanted applicators in-situ during the brachytherapy course. Results With the presented device, treatment QA was feasible for the majority of patients. The CBCT scans of breast patients showed sufficient contrast between implanted catheters and tissue. For gynecologic patients, a distinct visualization of applicators was achieved in general. However, reasonable differentiations of organic soft tissues were not feasible. Conclusion The CBCT system allowed basic treatment QA measures for breast and gynecologic patients. For image-guidance during interventional brachytherapy procedures, the current image quality is not adequate. Substantial performance enhancements are required for intraoperative image-guidance.
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Affiliation(s)
- Andre Karius
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054, Erlangen, Germany. .,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany.
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Michael Lotter
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Stephan Kreppner
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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12
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Beisemann N, Mandelka E, El Barbari JS, Kreher B, Vetter SY, Grützner PA, Franke J. Software-Automated Implant Detection for Intraoperative 3D Imaging-First Clinical Evaluation on 214 Data Sets. J Digit Imaging 2022; 35:514-523. [PMID: 35146612 PMCID: PMC9156648 DOI: 10.1007/s10278-022-00588-w] [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: 03/02/2021] [Revised: 12/03/2021] [Accepted: 01/14/2022] [Indexed: 11/16/2022] Open
Abstract
Previous studies have demonstrated a frequent occurrence of screw/K-wire malpositioning during surgical fracture treatment under 2D fluoroscopy and a correspondingly high revision rate as a result of using intraoperative 3D imaging. In order to facilitate and accelerate the diagnosis of implant malpositioning in 3D data sets, this study investigates two versions of an implant detection software for mobile 3D C-arms in terms of their detection performance based on comparison with manual evaluation. The 3D data sets of patients who had received surgical fracture treatment at five anatomical regions were extracted from the research database. First, manual evaluation of the data sets was performed, and the number of implanted implants was assessed. For 25 data sets, the time required by four investigators to adjust each implant was monitored. Subsequently, the evaluation was performed using both software versions based on the following detection parameters: true-positive-rate, false-negative-rate, false-detection-rate and positive predictive value. Furthermore, the causes of false positive and false negative detected implants depending on the anatomical region were investigated. Two hundred fourteen data sets with overall 1767 implants were included. The detection parameters were significantly improved (p<.001) from version 1 to version 2 of the implant detection software. Automatic evaluation required an average of 4.1±0.4 s while manual evaluation was completed in 136.15±72.9 s (p<.001), with a statistically significant difference between experienced and inexperienced users (p=.005). In summary, version 2 of the implant detection software achieved significantly better results. The time saved by using the software could contribute to optimizing the intraoperative workflow.
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Affiliation(s)
- Nils Beisemann
- Medical Imaging and Navigation in Trauma and Orthopedic Surgery (MINTOS), BG Trauma Center Ludwigshafen, Ludwig-Guttmann-Str. 13, 67071, Ludwigshafen, Germany
| | - Eric Mandelka
- Medical Imaging and Navigation in Trauma and Orthopedic Surgery (MINTOS), BG Trauma Center Ludwigshafen, Ludwig-Guttmann-Str. 13, 67071, Ludwigshafen, Germany
| | - Jan S El Barbari
- Medical Imaging and Navigation in Trauma and Orthopedic Surgery (MINTOS), BG Trauma Center Ludwigshafen, Ludwig-Guttmann-Str. 13, 67071, Ludwigshafen, Germany
| | | | - Sven Y Vetter
- Medical Imaging and Navigation in Trauma and Orthopedic Surgery (MINTOS), BG Trauma Center Ludwigshafen, Ludwig-Guttmann-Str. 13, 67071, Ludwigshafen, Germany
| | - Paul Alfred Grützner
- Medical Imaging and Navigation in Trauma and Orthopedic Surgery (MINTOS), BG Trauma Center Ludwigshafen, Ludwig-Guttmann-Str. 13, 67071, Ludwigshafen, Germany
| | - Jochen Franke
- Medical Imaging and Navigation in Trauma and Orthopedic Surgery (MINTOS), BG Trauma Center Ludwigshafen, Ludwig-Guttmann-Str. 13, 67071, Ludwigshafen, Germany.
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13
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Karius A, Karolczak M, Strnad V, Bert C. Technical evaluation of the cone-beam computed tomography imaging performance of a novel, mobile, gantry-based X-ray system for brachytherapy. J Appl Clin Med Phys 2021; 23:e13501. [PMID: 34905285 PMCID: PMC8833290 DOI: 10.1002/acm2.13501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/21/2021] [Accepted: 11/29/2021] [Indexed: 12/11/2022] Open
Abstract
Purpose A novel, mobile cone‐beam computed tomography (CBCT) system for image‐guided adaptive brachytherapy was recently deployed at our hospital as worldwide first site. Prior to the device's clinical operation, a profound characterization of its imaging performance was conducted. This was essential to optimize both the imaging workflow and image quality for achieving the best possible clinical outcomes. We present the results of our investigations. Methods The novel CBCT‐system features a ring gantry with 121 cm clearance as well as a 43.2 × 43.2 cm2 flat‐panel detector, and is controlled via a tablet‐personal computer (PC). For evaluating its imaging performance, the geometric reproducibility as well as imaging fidelity, computed tomography (CT)‐number accuracy, uniformity, contrast‐noise‐ratio (CNR), noise characteristics, and spatial resolution as fundamental image quality parameters were assessed. As dose metric the weighted cone‐beam dose index (CBDIw) was measured. Image quality was evaluated using standard quality assurance (QA) as well as anthropomorphic upper torso and breast phantoms. Both in‐house and manufacturer protocols for abdomen, pelvis, and breast imaging were examined. Results Using the in‐house protocols, the QA phantom scans showed altogether a high image quality, with high CT‐number accuracy (R2 > 0.97) and uniformity (<12 Hounsfield Unit (HU) cupping), reasonable noise and imaging fidelity, and good CNR at bone–tissue transitions of up to 28:1. Spatial resolution was strongly limited by geometric instabilities of the device. The breast phantom scans fulfilled clinical requirements, whereas the abdomen and pelvis scans showed severe artifacts, particularly at air/bone–tissue transitions. Conclusion With the novel CBCT‐system, achieving a high image quality appears possible in principle. However, adaptations of the standard protocols, performance enhancements in image reconstruction referring to artifact reductions, as well as the extinction of geometric instabilities are imperative.
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Affiliation(s)
- Andre Karius
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Universitätsstraße 27, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Marek Karolczak
- Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nuremberg, Henkestraße 91, Erlangen, Germany
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Universitätsstraße 27, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Universitätsstraße 27, Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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14
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Benn BS, Romero AO, Bawaadam H, Ivanick N, Lum M, Krishna G. Cone Beam CT Guidance Improves Transbronchial Lung Cryobiopsy Safety. Lung 2021; 199:485-492. [PMID: 34495390 DOI: 10.1007/s00408-021-00473-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 08/29/2021] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Determining the cause of diffuse parenchymal lung disease (DPLD) is challenging. While surgical lung biopsy has been the standard approach, transbronchial lung cryobiopsy (TBLC) represents a minimally invasive alternative with an acceptable safety profile and reasonable accuracy. In this study, we prospectively assessed whether the use of cone beam CT (CBCT) coupled with a novel bronchoscope holder and prophylactic administration of vasoconstricting medications decreases potential complications and improves diagnostic accuracy when performing TBLC. METHODS 33 patients presenting for evaluation of newly diagnosed DPLD were enrolled. Demographic data, pulmonary function values, chest imaging pattern, procedural information, and diagnosis were recorded. RESULTS Mean patient age was 67, with the majority Caucasian (n = 26, 79%) and male (n = 20, 61%). Mean pulmonary function values revealed restrictive lung disease (76 ± 14% predicted) and diffusing capacity impairment (52 ± 16%). A non-usual interstitial pneumonia imaging pattern was commonly seen (n = 20, 61%). CBCT guided TBLC was performed in one lobe (n = 29, 88%) or two lobes (n = 4, 12%) with mean probe-to-pleura distance of 4.2 ± 1.3 mm. No peri or post procedural complications occurred. 32 patients (97%) received a histological diagnosis with a final multidisciplinary conference diagnosis possible for 32 (97%). CONCLUSION CBCT guided TBLC coupled with a novel articulating scope holder and prophylactic phenylephrine administration has the potential to increase safety and diagnostic yield for patients with newly identified DPLD. Future studies comparing different aspects of this approach in isolation and with other modalities have the potential to refine this procedure to improve patient care.
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Affiliation(s)
- Bryan S Benn
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Medical College of Wisconsin, 8701 W Watertown Plank, Milwaukee, WI, 53226, USA.
| | - Arthur Oliver Romero
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine, University of California, San Francisco, CA, USA.,Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Hasnain Bawaadam
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Nathaniel Ivanick
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine, University of California, San Francisco, CA, USA.,Department of Pulmonary Medicine, Roswell Park Cancer Center, Buffalo, NY, USA
| | - Mendy Lum
- Respiratory Care Services, El Camino Health, Mountain View, CA, USA
| | - Ganesh Krishna
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine, University of California, San Francisco, CA, USA.,Division of Pulmonary and Critical Care Medicine, Department of Medicine, Palo Alto Medical Foundation, Palo Alto, CA, USA
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15
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Hsieh MJ, Chou PL, Fang HY, Wen CT, Chao YK. Single-step localization and excision of small pulmonary nodules using a mobile 3D C-arm. Interact Cardiovasc Thorac Surg 2021; 33:885-891. [PMID: 34291295 DOI: 10.1093/icvts/ivab182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/11/2021] [Accepted: 06/03/2021] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES The use of a hybrid operating room equipped with robotic C-arm cone-beam computed tomography for single-step localization and excision of small pulmonary nodules finds high cost barriers. The new generation of 3D C-arm system not only depicts soft tissues with high contrast but also offers a more affordable and sustainable solution. This approach has been chiefly applied in the field of orthopedic surgery. In this case series, we describe the use of a mobile 3D C-arm system for localizing and removing small pulmonary nodules. METHODS Between July and September 2020, we identified 14 patients who underwent localization and removal of small pulmonary nodules with a 3D C-arm system. We retrospectively reviewed clinical records to document the feasibility and safety of the procedure. RESULTS The median tumour size was 7.5 mm [interquartile range (IQR): 5 - 9.75 mm], with a median distance from the pleural surface of 4.2 mm (IQR: 0.5 - 6.45 mm). We successfully visualized all of the pulmonary lesions by intraoperative CT imaging. Localization was achieved in 13 patients, who subsequently underwent complete thoracoscopic resection. The median time required to localize lesions was 41.5 min (IQR: 33.75 - 53.25 min), with a median radiation exposure (expressed through the skin absorbed dose) of 143.45 mGy (IQR: 86.1 - 194.6 mGy). Failure to localize occurred in 1 patient because of pneumothorax caused by repeated needle puncture. All patients were successfully discharged and the median length of stay was 2.5 days (IQR: 2 - 3 days). CONCLUSIONS This case series demonstrates the feasibility of single-step localization and excision of small pulmonary nodules using a mobile 3D C-arm.
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Affiliation(s)
- Ming-Ju Hsieh
- Division of Thoracic Surgery, Chang Gung Memorial Hospital-Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Pin-Li Chou
- Division of Thoracic Surgery, Chang Gung Memorial Hospital-Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Hsin-Yueh Fang
- Division of Thoracic Surgery, Chang Gung Memorial Hospital-Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Tsung Wen
- Division of Thoracic Surgery, Chang Gung Memorial Hospital-Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yin-Kai Chao
- Division of Thoracic Surgery, Chang Gung Memorial Hospital-Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan
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16
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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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17
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Vijayan RC, Han R, Wu P, Sheth NM, Ketcha MD, Vagdargi P, Vogt S, Kleinszig G, Osgood GM, Siewerdsen JH, Uneri A. Development of a fluoroscopically guided robotic assistant for instrument placement in pelvic trauma surgery. J Med Imaging (Bellingham) 2021; 8:035001. [PMID: 34124283 PMCID: PMC8189698 DOI: 10.1117/1.jmi.8.3.035001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 05/21/2021] [Indexed: 11/14/2022] Open
Abstract
Purpose: A method for fluoroscopic guidance of a robotic assistant is presented for instrument placement in pelvic trauma surgery. The solution uses fluoroscopic images acquired in standard clinical workflow and helps avoid repeat fluoroscopy commonly performed during implant guidance. Approach: Images acquired from a mobile C-arm are used to perform 3D-2D registration of both the patient (via patient CT) and the robot (via CAD model of a surgical instrument attached to its end effector, e.g; a drill guide), guiding the robot to target trajectories defined in the patient CT. The proposed approach avoids C-arm gantry motion, instead manipulating the robot to acquire disparate views of the instrument. Phantom and cadaver studies were performed to determine operating parameters and assess the accuracy of the proposed approach in aligning a standard drill guide instrument. Results: The proposed approach achieved average drill guide tip placement accuracy of 1.57 ± 0.47 mm and angular alignment of 0.35 ± 0.32 deg in phantom studies. The errors remained within 2 mm and 1 deg in cadaver experiments, comparable to the margins of errors provided by surgical trackers (but operating without the need for external tracking). Conclusions: By operating at a fixed fluoroscopic perspective and eliminating the need for encoded C-arm gantry movement, the proposed approach simplifies and expedites the registration of image-guided robotic assistants and can be used with simple, non-calibrated, non-encoded, and non-isocentric C-arm systems to accurately guide a robotic device in a manner that is compatible with the surgical workflow.
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Affiliation(s)
- Rohan C. Vijayan
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
| | - Runze Han
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
| | - Pengwei Wu
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
| | - Niral M. Sheth
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
| | - Michael D. Ketcha
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
| | - Prasad Vagdargi
- Johns Hopkins University, Department of Computer Science, Baltimore, Maryland, United States
| | | | | | - Greg M. Osgood
- Johns Hopkins Medicine, Department of Orthopaedic Surgery, Baltimore, Maryland, United States
| | - Jeffrey H. Siewerdsen
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
- Johns Hopkins University, Department of Computer Science, Baltimore, Maryland, United States
| | - Ali Uneri
- Johns Hopkins University, Department of Biomedical Engineering, Baltimore, Maryland, United States
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18
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Wu P, Boone JM, Hernandez AM, Mahesh M, Siewerdsen JH. Theory, method, and test tools for determination of 3D MTF characteristics in cone-beam CT. Med Phys 2021; 48:2772-2789. [PMID: 33660261 DOI: 10.1002/mp.14820] [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: 10/09/2020] [Revised: 02/19/2021] [Accepted: 02/23/2021] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The modulation transfer function (MTF) is widely used as an objective metric of spatial resolution of medical imaging systems. Despite advances in capability for three-dimensional (3D) isotropic spatial resolution in computed tomography (CT) and cone-beam CT (CBCT), MTF evaluation for such systems is typically reported only in the axial plane, and practical methodology for assessment of fully 3D spatial resolution characteristics is lacking. This work reviews fundamental theoretical relationships of two-dimensional (2D) and 3D spread functions and reports practical methods and test tools for analysis of 3D MTF in CBCT. METHODS Fundamental aspects of 2D and 3D MTF measurement are reviewed within a common notational framework, and three MTF test tools with analysis code are reported and made available online (https://istar.jhu.edu/downloads/): (a) a multi-wire tool for measurement of the axial plane MTF [denoted as M T F ( f r ; φ = 0 ∘ ) , where φ is the measurement angle out of the axial plane] as a function of position in the axial plane; (b) a wedge tool for measurement of the MTF in any direction in the 3D Fourier domain [e.g., φ = 45°, denoted as M T F ( f r ; φ = 45 ∘ ) ]; and (c) a sphere tool for measurement of the MTF in any or all directions in the 3D Fourier domain. Experiments were performed on a mobile C-arm with CBCT capability, showing that M T F ( f r ; φ = 45 ∘ ) yields an informative one-dimensional (1D) representation of the overall 3D spatial resolution characteristics, capturing important characteristics of the 3D MTF that might be missed in conventional analysis. The effects of anisotropic filters and detector readout mode were investigated, and the extent to which a system can be said to provide "isotropic" resolution was evaluated by quantitative comparison of MTF at various φ . RESULTS All three test tools provided consistent measurement of M T F ( f r ; φ = 0 ∘ ) , and the wedge and sphere tools demonstrated how measurement of the MTF in directions outside the axial plane ( φ > 0 ∘ ) can reveal spatial resolution characteristics to which conventional axial MTF measurement is blind. The wedge tool was shown to reduce statistical measurement error compared to the sphere tool due to improved sampling, and the sphere tool was shown to provide a basis for measurement of the MTF in any or all directions (outside the null cone) from a single scan. The C-arm system exhibited non-isotropic spatial resolution with conventional non-isotropic 1D apodization filters (i.e., frequency cutoff filters) - which is common in CBCT - and implementation of isotropic 2D apodization yielded quantifiably isotropic MTF. Asymmetric pixel binning modes were similarly shown to impart non-isotropic effects on the 3D MTF, and the overall 3D MTF characteristics were evident in each case with a single, 1D measurement of the 1D M T F ( f r ; φ = 45 ∘ ). CONCLUSION Three test tools and corresponding MTF analysis methods were presented within a consistent framework for analysis of 3D spatial resolution characteristics in a manner amenable to routine, practical measurements. Experiments on a CBCT C-arm validated many intuitive aspects of 3D spatial resolution and quantified the extent to which a CBCT system may be considered to have isotropic resolution. Measurement of M T F ( f r ; φ = 45 ∘ ) provided a practical 1D measure of the underlying 3D MTF characteristics and is extensible to other CT or CBCT systems offering high, isotropic spatial resolution.
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Affiliation(s)
- Pengwei Wu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - John M Boone
- Department of Radiology, University of California, Davis, Davis, CA, 95616, USA
| | - Andrew M Hernandez
- Department of Radiology, University of California, Davis, Davis, CA, 95616, USA
| | - Mahadevappa Mahesh
- Department of Radiology, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Jeffrey H Siewerdsen
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA.,Department of Radiology, Johns Hopkins University, Baltimore, MD, 21205, USA
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19
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Robotic-Assisted Navigation Bronchoscopy as a Paradigm Shift in Peripheral Lung Access. Lung 2021; 199:177-186. [PMID: 33547938 DOI: 10.1007/s00408-021-00421-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 01/18/2021] [Indexed: 10/22/2022]
Abstract
INTRODUCTION The sensitivity of suspicious lung nodules biopsied by currently available techniques is suboptimal. Robotic-assisted navigation bronchoscopy (RANB) is a novel method for biopsying lung nodules. Our study objective was to determine the sensitivity for malignancy and overall diagnostic accuracy for RANB when combined with cone beam CT (CBCT) for secondary confirmation. METHODS 52 consecutive patients were prospectively enrolled. Demographic data, nodule characteristics, procedural information, and follow-up results were obtained. RESULTS Mean patient age was 66, with the majority Caucasian (73%) females (65%) with a similar number of never (46%) and former (46%) smokers. 15 patients had a history of cancer and 3 had a prior thoracic surgery. 59 total nodules were included as 7 patients had two nodules biopsied. Mean nodule diameter was < 2 cm in all dimension with the majority solid (41, 70%) and located in the upper lobes (left: 22, 37%; right: 17, 29%). Bronchus sign was absent (32, 54%) or present (27, 46%) in a similar number. All nodules were successfully reached with nine (15%) requiring minor directional changes after initial cone beam CT. A tissue diagnosis was obtained in 83% (49/59) of biopsied nodules, with malignancy (31, 65%) most common. Including all biopsy results and follow-up imaging, we obtained an 84% (31/37) procedural sensitivity for malignancy and an overall 86% (51/59) diagnostic yield. CONCLUSION RANB with CBCT increases sensitivity for malignancy and diagnostic accuracy of lung nodule biopsies. Combining these modalities has the potential to shift the diagnostic approach to pulmonary nodules.
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Sadoughi A, Virdi S. Mobile 3D Intraprocedural Fluoroscopy in Combination With Ultrathin Bronchoscopy for Biopsy of Peripheral Lung Nodules. J Bronchology Interv Pulmonol 2021; 28:76-80. [PMID: 32947357 PMCID: PMC7742211 DOI: 10.1097/lbr.0000000000000711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 08/07/2020] [Indexed: 11/26/2022]
Abstract
Despite development of multiple technologies, distinguishing benign from malignant lung nodules when they are still small in size is challenging. A high yield and minimally invasive bronchoscopic technology with low cost for diagnosis of small lung lesions is needed in pulmonary and lung cancer clinical practice. Peripheral airway bronchoscopy using thin and most recently ultrathin bronchoscopes improve visualization of small airways. The novel mobile 2D/3D C-Arm fluoroscopy system is a complementary tool along with radial endobronchial ultrasound in detecting small lung nodules with real-time high-quality multidimensional image confirmation during bronchoscopy. This combined technology can be easily acquired in any bronchoscopy room, and potentially affect lung nodule practice significantly.
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Affiliation(s)
- Ali Sadoughi
- Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY
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Kalchiem-Dekel O, Fuentes P, Bott MJ, Beattie JA, Lee RP, Chawla M, Husta BC. Multiplanar 3D fluoroscopy redefines tool-lesion relationship during robotic-assisted bronchoscopy. Respirology 2020; 26:120-123. [PMID: 33140495 DOI: 10.1111/resp.13966] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/22/2020] [Accepted: 10/12/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Or Kalchiem-Dekel
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Paige Fuentes
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Matthew J Bott
- Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jason A Beattie
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Robert P Lee
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Mohit Chawla
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Bryan C Husta
- Section of Interventional Pulmonology, Pulmonary Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Wu P, Sheth N, Sisniega A, Uneri A, Han R, Vijayan R, Vagdargi P, Kreher B, Kunze H, Kleinszig G, Vogt S, Lo SF, Theodore N, Siewerdsen JH. C-arm orbits for metal artifact avoidance (MAA) in cone-beam CT. Phys Med Biol 2020; 65:165012. [PMID: 32428891 PMCID: PMC8650760 DOI: 10.1088/1361-6560/ab9454] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Metal artifacts present a challenge to cone-beam CT (CBCT) image-guided surgery, obscuring visualization of metal instruments and adjacent anatomy-often in the very region of interest pertinent to the imaging/surgical tasks. We present a method to reduce the influence of metal artifacts by prospectively defining an image acquisition protocol-viz., the C-arm source-detector orbit-that mitigates metal-induced biases in the projection data. The metal artifact avoidance (MAA) method is compatible with simple mobile C-arms, does not require exact prior information on the patient or metal implants, and is consistent with 3D filtered backprojection (FBP), more advanced (e.g. polyenergetic) model-based image reconstruction (MBIR), and metal artifact reduction (MAR) post-processing methods. The MAA method consists of: (i) coarse localization of metal objects in the field-of-view (FOV) via two or more low-dose scout projection views and segmentation (e.g. a simple U-Net) in coarse backprojection; (ii) model-based prediction of metal-induced x-ray spectral shift for all source-detector vertices accessible by the imaging system (e.g. gantry rotation and tilt angles); and (iii) identification of a circular or non-circular orbit that reduces the variation in spectral shift. The method was developed, tested, and evaluated in a series of studies presenting increasing levels of complexity and realism, including digital simulations, phantom experiment, and cadaver experiment in the context of image-guided spine surgery (pedicle screw implants). The MAA method accurately predicted tilted circular and non-circular orbits that reduced the magnitude of metal artifacts in CBCT reconstructions. Realistic distributions of metal instrumentation were successfully localized (0.71 median Dice coefficient) from 2-6 low-dose scout views even in complex anatomical scenes. The MAA-predicted tilted circular orbits reduced root-mean-square error (RMSE) in 3D image reconstructions by 46%-70% and 'blooming' artifacts (apparent width of the screw shaft) by 20-45%. Non-circular orbits defined by MAA achieved a further ∼46% reduction in RMSE compared to the best (tilted) circular orbit. The MAA method presents a practical means to predict C-arm orbits that minimize spectral bias from metal instrumentation. Resulting orbits-either simple tilted circular orbits or more complex non-circular orbits that can be executed with a motorized multi-axis C-arm-exhibited substantial reduction of metal artifacts in raw CBCT reconstructions by virtue of higher fidelity projection data, which are in turn compatible with subsequent MAR post-processing and/or polyenergetic MBIR to further reduce artifacts.
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Affiliation(s)
- P Wu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
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