1
|
Stojadinović M, Mašulović D, Kadija M, Milovanović D, Milić N, Marković K, Ciraj-Bjelac O. Optimization of the "Perth CT" Protocol for Preoperative Planning and Postoperative Evaluation in Total Knee Arthroplasty. Medicina (Kaunas) 2024; 60:98. [PMID: 38256359 PMCID: PMC10818486 DOI: 10.3390/medicina60010098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 12/24/2023] [Accepted: 12/27/2023] [Indexed: 01/24/2024]
Abstract
Background and Objectives: Total knee arthroplasty (TKA) has become the treatment of choice for advanced osteoarthritis. The aim of this paper was to show the possibilities of optimizing the Perth CT protocol, which is highly effective for preoperative planning and postoperative assessment of alignment. Materials and Methods: The cross-sectional study comprised 16 patients for preoperative planning or postoperative evaluation of TKA. All patients were examined with the standard and optimized Perth CT protocol using advance techniques, including automatic exposure control (AEC), iterative image reconstruction (IR), as well as a single-energy projection-based metal artifact reduction algorithm for eliminating prosthesis artifacts. The effective radiation dose (E) was determined based on the dose report. Imaging quality is determined according to subjective and objective (values of signal to noise ratio (SdNR) and figure of merit (FOM)) criteria. Results: The effective radiation dose with the optimized protocol was significantly lower compared to the standard protocol (p < 0.001), while in patients with the knee prosthesis, E increased significantly less with the optimized protocol compared to the standard protocol. No significant difference was observed in the subjective evaluation of image quality between protocols (p > 0.05). Analyzing the objective criteria for image quality optimized protocols resulted in lower SdNR values and higher FOM values. No significant difference of image quality was determined using the SdNR and FOM as per the specified protocols and parts of extremities, and for the presence of prothesis. Conclusions: Retrospecting the ALARA ('As Low As Reasonably Achievable') principles, it is possible to optimize the Perth CT protocol by reducing the kV and mAs values and by changing the collimation and increasing the pitch factor. Advanced IR techniques were used in both protocols, and AEC was used in the optimized protocol. The effective dose of radiation can be reduced five times, and the image quality will be satisfactory.
Collapse
Affiliation(s)
- Milica Stojadinović
- Center for Radiology, University Clinical Center of Serbia, Pasterova 2, 11000 Belgrade, Serbia;
| | - Dragan Mašulović
- Center for Radiology, University Clinical Center of Serbia, Pasterova 2, 11000 Belgrade, Serbia;
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia; (M.K.); (N.M.)
| | - Marko Kadija
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia; (M.K.); (N.M.)
- Clinic for Orthopedic Surgery and Traumatology, University Clinical Center of Serbia, Pasterova 2, 11000 Belgrade, Serbia
| | - Darko Milovanović
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia; (M.K.); (N.M.)
- Clinic for Orthopedic Surgery and Traumatology, University Clinical Center of Serbia, Pasterova 2, 11000 Belgrade, Serbia
| | - Nataša Milić
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia; (M.K.); (N.M.)
- Institute for Medical Statistic and Informatics, University Clinical Center of Serbia, Pasterova 2, 11000 Belgrade, Serbia;
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA
| | - Ksenija Marković
- Institute for Medical Statistic and Informatics, University Clinical Center of Serbia, Pasterova 2, 11000 Belgrade, Serbia;
| | - Olivera Ciraj-Bjelac
- Vinca Institute of Nuclear Sciences—National Institute of the Republic of Serbia, 11000 Belgrade, Serbia;
- Faculty of Electrical Engineering, University of Belgrade, 11000 Belgrade, Serbia
| |
Collapse
|
2
|
Abstract
ABSTRACT Computed tomography (CT) dramatically improved the capabilities of diagnostic and interventional radiology. Starting in the early 1970s, this imaging modality is still evolving, although tremendous improvements in scan speed, volume coverage, spatial and soft tissue resolution, as well as dose reduction have been achieved. Tube current modulation, automated exposure control, anatomy-based tube voltage (kV) selection, advanced x-ray beam filtration, and iterative image reconstruction techniques improved image quality and decreased radiation exposure. Cardiac imaging triggered the demand for high temporal resolution, volume acquisition, and high pitch modes with electrocardiogram synchronization. Plaque imaging in cardiac CT as well as lung and bone imaging demand for high spatial resolution. Today, we see a transition of photon-counting detectors from experimental and research prototype setups into commercially available systems integrated in patient care. Moreover, with respect to CT technology and CT image formation, artificial intelligence is increasingly used in patient positioning, protocol adjustment, and image reconstruction, but also in image preprocessing or postprocessing. The aim of this article is to give an overview of the technical specifications of up-to-date available whole-body and dedicated CT systems, as well as hardware and software innovations for CT systems in the near future.
Collapse
|
3
|
Stein T, Rau A, Russe MF, Arnold P, Faby S, Ulzheimer S, Weis M, Froelich MF, Overhoff D, Horger M, Hagen F, Bongers M, Nikolaou K, Schönberg SO, Bamberg F, Weiß J. Photon-Counting Computed Tomography - Basic Principles, Potenzial Benefits, and Initial Clinical Experience. ROFO-FORTSCHR RONTG 2023; 195:691-698. [PMID: 36863367 DOI: 10.1055/a-2018-3396] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
BACKGROUND Photon-counting computed tomography (PCCT) is a promising new technology with the potential to fundamentally change today's workflows in the daily routine and to provide new quantitative imaging information to improve clinical decision-making and patient management. METHOD The content of this review is based on an unrestricted literature search on PubMed and Google Scholar using the search terms "Photon-Counting CT", "Photon-Counting detector", "spectral CT", "Computed Tomography" as well as on the authors' experience. RESULTS The fundamental difference with respect to the currently established energy-integrating CT detectors is that PCCT allows counting of every single photon at the detector level. Based on the identified literature, PCCT phantom measurements and initial clinical studies have demonstrated that the new technology allows improved spatial resolution, reduced image noise, and new possibilities for advanced quantitative image postprocessing. CONCLUSION For clinical practice, the potential benefits include fewer beam hardening artifacts, radiation dose reduction, and the use of new contrast agents. In this review, we will discuss basic technical principles and potential clinical benefits and demonstrate first clinical use cases. KEY POINTS · Photon-counting computed tomography (PCCT) has been implemented in the clinical routine. · Compared to energy-integrating detector CT, PCCT allows the reduction of electronic image noise. · PCCT provides increased spatial resolution and a higher contrast-to-noise ratio. · The novel detector technology allows the quantification of spectral information. CITATION FORMAT · Stein T, Rau A, Russe MF et al. Photon-Counting Computed Tomography - Basic Principles, Potenzial Benefits, and Initial Clinical Experience. Fortschr Röntgenstr 2023; 195: 691 - 698.
Collapse
Affiliation(s)
- Thomas Stein
- Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Germany
| | - Alexander Rau
- Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Germany
| | - Maximilian Frederik Russe
- Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Germany
| | - Philipp Arnold
- Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Germany
| | - Sebastian Faby
- Computed Tomography, Siemens Healthcare GmbH, Forchheim, Germany
| | - Stefan Ulzheimer
- Computed Tomography, Siemens Healthcare GmbH, Forchheim, Germany
| | - Meike Weis
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Germany
| | - Matthias F Froelich
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Germany
| | - Daniel Overhoff
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Germany
| | - Marius Horger
- Department of Radiology, University Hospitals Tübingen, Germany
| | - Florian Hagen
- Department of Radiology, University Hospitals Tübingen, Germany
| | - Malte Bongers
- Department of Radiology, University Hospitals Tübingen, Germany
| | | | - Stefan O Schönberg
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Germany
| | - Fabian Bamberg
- Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Germany
| | - Jakob Weiß
- Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Germany
| |
Collapse
|
4
|
Kim S, Jeong WK, Choi JH, Kim JH, Chun M. Development of deep learning-assisted overscan decision algorithm in low-dose chest CT: Application to lung cancer screening in Korean National CT accreditation program. PLoS One 2022; 17:e0275531. [PMID: 36174098 PMCID: PMC9522252 DOI: 10.1371/journal.pone.0275531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 09/19/2022] [Indexed: 12/01/2022] Open
Abstract
We propose a deep learning-assisted overscan decision algorithm in chest low-dose computed tomography (LDCT) applicable to the lung cancer screening. The algorithm reflects the radiologists’ subjective evaluation criteria according to the Korea institute for accreditation of medical imaging (KIAMI) guidelines, where it judges whether a scan range is beyond landmarks’ criterion. The algorithm consists of three stages: deep learning-based landmark segmentation, rule-based logical operations, and overscan determination. A total of 210 cases from a single institution (internal data) and 50 cases from 47 institutions (external data) were utilized for performance evaluation. Area under the receiver operating characteristic (AUROC), accuracy, sensitivity, specificity, and Cohen’s kappa were used as evaluation metrics. Fisher’s exact test was performed to present statistical significance for the overscan detectability, and univariate logistic regression analyses were performed for validation. Furthermore, an excessive effective dose was estimated by employing the amount of overscan and the absorbed dose to effective dose conversion factor. The algorithm presented AUROC values of 0.976 (95% confidence interval [CI]: 0.925–0.987) and 0.997 (95% CI: 0.800–0.999) for internal and external dataset, respectively. All metrics showed average performance scores greater than 90% in each evaluation dataset. The AI-assisted overscan decision and the radiologist’s manual evaluation showed a statistically significance showing a p-value less than 0.001 in Fisher’s exact test. In the logistic regression analysis, demographics (age and sex), data source, CT vendor, and slice thickness showed no statistical significance on the algorithm (each p-value > 0.05). Furthermore, the estimated excessive effective doses were 0.02 ± 0.01 mSv and 0.03 ± 0.05 mSv for each dataset, not a concern within slight deviations from an acceptable scan range. We hope that our proposed overscan decision algorithm enables the retrospective scan range monitoring in LDCT for lung cancer screening program, and follows an as low as reasonably achievable (ALARA) principle.
Collapse
Affiliation(s)
- Sihwan Kim
- Department of Applied Bioengineering, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Republic of Korea
- ClariPi Research, Seoul, Republic of Korea
| | - Woo Kyoung Jeong
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jin Hwa Choi
- Department of Radiation Oncology, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Jong Hyo Kim
- Department of Applied Bioengineering, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Republic of Korea
- ClariPi Research, Seoul, Republic of Korea
- Center for Medical-IT Convergence Technology Research, Advanced Institutes of Convergence Technology, Suwon, Republic of Korea
- Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Minsoo Chun
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
- Department of Radiation Oncology, Chung-Ang University Gwang Myeong Hospital, Gyeonggi-do, Republic of Korea
- * E-mail:
| |
Collapse
|