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Manako T, Imade S, Yamagami N, Yamamoto S, Uchio Y. The clinical outcomes of scaphoid nonunion treated with a precisely processed autologous bone screw: a case series. Arch Orthop Trauma Surg 2023; 143:627-635. [PMID: 34347123 DOI: 10.1007/s00402-021-04092-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 07/27/2021] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Metal implants and bioabsorbable implants are frequently used in orthopaedic surgery, but they have some disadvantages. The usefulness of autologous bone has been described, and a method to precisely process autologous bone into implants such as screws and apply the implants clinically has been desired. We created a new system for manufacturing autologous bone screws during surgery and report five cases of scaphoid nonunion treated with precise autologous bone screws made from the tibial cortex using the new system. PATIENTS AND METHODS From 2012 through 2017, seven patients were diagnosed with scaphoid nonunion at our hospital and based on the inclusion/exclusion criteria, five of them were analyzed herein. The surgery was performed according to Zaidemberg's technique. The bone screw in each case was made from autologous tibial cortex using a numerically controlled lathe (model MTS4, Nano Co., Yokohama, Japan) under sterile conditions. The change in each patient's modified Mayo wrist score between the preoperative examination and at the final survey was determined, as were complications. RESULTS The median modified Mayo wrist score improved significantly from 65 to 95 points. All patients who were followed for > 2 years fused at a median duration of 3.5 months. Bone regeneration was confirmed at the donor sites in all cases. One fracture at the donor site occurred as a severe complication. CONCLUSIONS Precisely shaped autologous bone screws manufactured by a computer-assisted machine, together with a vascularized bone graft, may be a useful technique for treating scaphoid nonunions; these screws had good stability and bone replacement. Careful observation of the donor site is required. LEVEL OF EVIDENCE IV.
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Affiliation(s)
- Takuya Manako
- Department of Orthopaedic Surgery, Faculty of Medicine, Shimane University, 89-1, Enya, Izumo, Shimane, 693-8501, Japan.
| | - Shinji Imade
- Department of Orthopaedic Surgery, Faculty of Medicine, Shimane University, 89-1, Enya, Izumo, Shimane, 693-8501, Japan
| | - Nobuo Yamagami
- Department of Orthopaedic Surgery, Faculty of Medicine, Shimane University, 89-1, Enya, Izumo, Shimane, 693-8501, Japan
| | - Soichiro Yamamoto
- Department of Orthopaedic Surgery, Faculty of Medicine, Shimane University, 89-1, Enya, Izumo, Shimane, 693-8501, Japan
| | - Yuji Uchio
- Department of Orthopaedic Surgery, Faculty of Medicine, Shimane University, 89-1, Enya, Izumo, Shimane, 693-8501, Japan
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What does the orthopaedic surgeon want in the radiology report? J Clin Orthop Trauma 2021; 21:101530. [PMID: 34386345 PMCID: PMC8333142 DOI: 10.1016/j.jcot.2021.101530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 07/21/2021] [Indexed: 02/07/2023] Open
Abstract
Complementary imaging is crucial in the diagnosis and management of the spectrum of Musculoskeletal (MSK) pathologies. Like in all medical specialities, its role in trauma and orthopaedic conditions has evolved. A radiology report following an imaging study should provide an accurate, timely interpretation of images and be presented in a format that allows formal analysis or clarification of a patient's diagnostic dilemma. It is essential that it is descriptive enough to allow clinico-pathological correlation to a patient's condition. A high-quality report follows clinical governance processes, provides clinical feedback, and when appropriate, incorporates advice regarding differential diagnosis or further investigation/management that can be undertaken, permitting the attending clinician to formulate a suitable treatment plan for their patient. In this narrative we explore common radiological investigations and reporting information in trauma and orthopaedic conditions, which would be useful to the attending surgeon.
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Ahlawat S, McColl M, Morris CD, Fayad LM. Pelvic bone tumor resection: post-operative imaging. Skeletal Radiol 2021; 50:1303-1316. [PMID: 33399942 DOI: 10.1007/s00256-020-03703-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/14/2020] [Accepted: 12/25/2020] [Indexed: 02/02/2023]
Abstract
The anatomic extent of a pelvic bone tumor and the need for reconstruction dictate the type of pelvic resection (limb salvage pelvic resection or amputation). If a pelvic bone tumor resection involves two or more critical anatomic structures (the sciatic nerve, femoral neurovascular bundle or the hip joint), then reasonable functional recovery after limb salvage is less likely and amputation should be considered. Both limb salvage and amputation approaches to the pelvis are technically arduous surgeries with significant associated morbidity and complications. As such, imaging plays an important role in the post-operative management of patients who have undergone pelvic bone tumor resection. In this article, we will review optimal imaging techniques as well as the expected post-operative appearance after pelvic bone tumor resection and important complications including infection, tumor recurrence, and complications related to complex soft tissue and osseous reconstruction.
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Affiliation(s)
- Shivani Ahlawat
- The Russell H. Morgan Department of Radiology & Radiological Science, The Johns Hopkins Medical Institutions, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
| | - Michael McColl
- The Russell H. Morgan Department of Radiology & Radiological Science, The Johns Hopkins Medical Institutions, 600 North Wolfe Street, Baltimore, MD, 21287, USA
| | - Carol D Morris
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Laura M Fayad
- The Russell H. Morgan Department of Radiology & Radiological Science, The Johns Hopkins Medical Institutions, 600 North Wolfe Street, Baltimore, MD, 21287, USA
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Reduction of CT artifacts from cardiac implantable electronic devices using a combination of virtual monoenergetic images and post-processing algorithms. Eur Radiol 2021; 31:7151-7161. [PMID: 33630164 PMCID: PMC8379133 DOI: 10.1007/s00330-021-07746-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/16/2020] [Accepted: 02/04/2021] [Indexed: 12/20/2022]
Abstract
OBJECTIVES To evaluate the reduction of artifacts from cardiac implantable electronic devices (CIEDs) by virtual monoenergetic images (VMI), metal artifact reduction (MAR) algorithms, and their combination (VMIMAR) derived from spectral detector CT (SDCT) of the chest compared to conventional CT images (CI). METHODS In this retrospective study, we included 34 patients (mean age 74.6 ± 8.6 years), who underwent a SDCT of the chest and had a CIED in place. CI, MAR, VMI, and VMIMAR (10 keV increment, range: 100-200 keV) were reconstructed. Mean and standard deviation of attenuation (HU) among hypo- and hyperdense artifacts adjacent to CIED generator and leads were determined using ROIs. Two radiologists qualitatively evaluated artifact reduction and diagnostic assessment of adjacent tissue. RESULTS Compared to CI, MAR and VMIMAR ≥ 100 keV significantly increased attenuation in hypodense and significantly decreased attenuation in hyperdense artifacts at CIED generator and leads (p < 0.05). VMI ≥ 100 keV alone only significantly decreased hyperdense artifacts at the generator (p < 0.05). Qualitatively, VMI ≥ 100 keV, MAR, and VMIMAR ≥ 100 keV provided significant reduction of hyper- and hypodense artifacts resulting from the generator and improved diagnostic assessment of surrounding structures (p < 0.05). Diagnostic assessment of structures adjoining to the leads was only improved by MAR and VMIMAR 100 keV (p < 0.05), whereas keV values ≥ 140 with and without MAR significantly worsened diagnostic assessment (p < 0.05). CONCLUSIONS The combination of VMI and MAR as well as MAR as a standalone approach provides effective reduction of artifacts from CIEDs. Still, higher keV values should be applied with caution due to a loss of soft tissue and vessel contrast along the leads. KEY POINTS • The combination of VMI and MAR as well as MAR as a standalone approach enables effective reduction of artifacts from CIEDs. • Higher keV values of both VMI and VMIMAR at CIED leads should be applied with caution since diagnostic assessment can be hampered by a loss of soft tissue and vessel contrast. • Recommended keV values for CIED generators are between 140 and 200 keV and for leads around 100 keV.
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5
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Gupta A, Obmann VC, Jordan M, Lennartz S, Obmann MM, Große Hokamp N, Zopfs D, Pennig L, Fürtjes G, Ramaiya N, Gilkeson R, Laukamp KR. CT artifacts after contrast media injection in chest imaging: evaluation of post-processing algorithms, virtual monoenergetic images and their combination for artifact reduction. Quant Imaging Med Surg 2021; 11:226-239. [PMID: 33392024 DOI: 10.21037/qims-20-435] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Background After injection into a brachial vein, high contrast media concentration in axillary and subclavian veins can cause artifacts that impair diagnostic utility. This study assessed artifact reduction by artifact-reduction-algorithms (ARA) and virtual-monoenergetic-images (VMI), as well as their combination (VMIARA) compared to conventional CT-images (CI). Methods Forty-six spectral-detector-CT (SDCT) examinations of patients that received ARA-reconstructions due to perivenous-artifacts were included in this retrospective study. CI, ARA, VMI, and VMIARA (range: 70-200 keV) were reconstructed. Objective analysis was performed with ROI-based assessment of mean and standard deviation of attenuation (HU) in hypo- and hyperdense artifacts and impaired muscle and arteries as well as artifact-free reference-tissue. Extent of artifact reduction, assessment of surrounding soft tissue and vessels, and appearance of new artifacts were rated visually by two radiologists. Results Hypo- and hyperdense artifacts showed significant improvement as evidenced by decreasing attenuation differences between artifact impaired and artifact-free reference tissue in ARA, VMI ≥80 keV, and VMIARA between 70-200 keV (e.g., CI/ARA/VMI100keV/VMIARA100keV: hypodense artifacts, (-)264.8±150.9/(-)87.1±78.9/(-)48.6±64.6/9.9±63.9 HU; P<0.001); hyperdense artifacts, 164.2±51.1/82.1±73.2/7.9±34.7/(-)17.3±50.7 HU; P<0.001). Artifacts impairing surrounding muscle and arteries were also reduced by all three approaches. In visual assessment, ARA, VMI ≥100 keV, and VMIARA between 70-200 keV also showed significant artifact reduction and improved assessment; however, for assessment of arteries improvement was not significant using ARA alone. New artifacts were reported, particularly at higher keV-values. Conclusions In presence of perivenous-artifacts, ARA, VMI and their combination allow for significant artifact reduction; however, their combination and VMI as a standalone approach yielded best results and should therefore be used, if available.
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Affiliation(s)
- Amit Gupta
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Verena Carola Obmann
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Michelle Jordan
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Markus Michael Obmann
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Nils Große Hokamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Lenhard Pennig
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Gina Fürtjes
- Center for Neurosurgery, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nikhil Ramaiya
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Robert Gilkeson
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Kai Roman Laukamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
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Blum A, Gillet R, Rauch A, Urbaneja A, Biouichi H, Dodin G, Germain E, Lombard C, Jaquet P, Louis M, Simon L, Gondim Teixeira P. 3D reconstructions, 4D imaging and postprocessing with CT in musculoskeletal disorders: Past, present and future. Diagn Interv Imaging 2020; 101:693-705. [PMID: 33036947 DOI: 10.1016/j.diii.2020.09.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/12/2020] [Accepted: 09/15/2020] [Indexed: 12/30/2022]
Abstract
Three-dimensional (3D) imaging and post processing are common tasks used daily in many disciplines. The purpose of this article is to review the new postprocessing tools available. Although 3D imaging can be applied to all anatomical regions and used with all imaging techniques, its most varied and relevant applications are found with computed tomography (CT) data in musculoskeletal imaging. These new applications include global illumination rendering (GIR), unfolded rib reformations, subtracted CT angiography for bone analysis, dynamic studies, temporal subtraction and image fusion. In all of these tasks, registration and segmentation are two basic processes that affect the quality of the results. GIR simulates the complete interaction of photons with the scanned object, providing photorealistic volume rendering. Reformations to unfold the rib cage allow more accurate and faster diagnosis of rib lesions. Dynamic CT can be applied to cinematic joint evaluations a well as to perfusion and angiographic studies. Finally, more traditional techniques, such as minimum intensity projection, might find new applications for bone evaluation with the advent of ultra-high-resolution CT scanners. These tools can be used synergistically to provide morphologic, topographic and functional information and increase the versatility of CT.
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Affiliation(s)
- A Blum
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France; Unité INSERM U1254 Imagerie Adaptative Diagnostique et Interventionnelle (IADI), CHRU of Nancy, 54511 Vandœuvre-lès-Nancy, France.
| | - R Gillet
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - A Rauch
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - A Urbaneja
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - H Biouichi
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - G Dodin
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - E Germain
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - C Lombard
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - P Jaquet
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - M Louis
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - L Simon
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France
| | - P Gondim Teixeira
- Guilloz Imaging Department, CHRU of Nancy, 54000 Nancy, France; Unité INSERM U1254 Imagerie Adaptative Diagnostique et Interventionnelle (IADI), CHRU of Nancy, 54511 Vandœuvre-lès-Nancy, France
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The Optimal Combination of Monochromatic and Metal Artifact Reconstruction Dual-energy CT to Evaluate Total Knee Replacement Arthroplasty. Eur J Radiol 2020; 132:109254. [PMID: 32956998 DOI: 10.1016/j.ejrad.2020.109254] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 06/23/2020] [Accepted: 08/19/2020] [Indexed: 11/23/2022]
Abstract
PURPOSE To evaluate the effects of gemstone spectral imaging-metal artifact reduction (GSI-MAR) on different dual-energy CT monochromatic images for patients with total knee replacement arthroplasty (TKRA) and to identify an appropriate protocol for clinical practice. METHOD We enrolled 34 patients with TKRA. CT images were iteratively reconstructed with or without GSI-MAR at different energy levels (70, 95, 115, and 140 keV). Two radiologists evaluated the objective and subjective image qualities and MAR-related new artifacts at the femoral and tibial levels. For objective analysis, the mean CT number and image noise of the selected regions of interest in the bone and muscle were recorded. To quantitatively evaluate the performance of GSI-MAR, a structural similarity index (SSIM) was used. For subjective analysis, streak artifacts and diagnostic confidence in detecting periprosthetic complications were assessed. Objective and subjective indicators were compared among the image combinations. RESULTS In the femoral component, 140 keV monochromatic energy images with GSI-MAR showed the lowest mean CT number, image noise, SSIM value, and streak artifacts, and the best diagnostic confidence. In the tibial component, the image noise differed significantly, but the SSIM and subjective indicators were similar among the image combinations. MAR-related new artifacts were noted in 14.7% of images, and all of them were observed in only the femoral component. CONCLUSION GSI-MAR with higher-energy monochromatic images showed fewer metal artifacts and better visualization. We recommend 140 keV with GSI-MAR for improving image quality and 140 keV without GSI-MAR for identifying MAR-related new artifacts when evaluating TKRA.
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Grandmougin A, Bakour O, Villani N, Baumann C, Rousseau H, Gondim Teixeira PA, Blum A. Metal artifact reduction for small metal implants on CT: Which image reconstruction algorithm performs better? Eur J Radiol 2020; 127:108970. [DOI: 10.1016/j.ejrad.2020.108970] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 01/27/2020] [Accepted: 03/11/2020] [Indexed: 12/16/2022]
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Zopfs D, Lennartz S, Pennig L, Glauner A, Abdullayev N, Bremm J, Große Hokamp N, Persigehl T, Kabbasch C, Borggrefe J, Laukamp KR. Virtual monoenergetic images and post-processing algorithms effectively reduce CT artifacts from intracranial aneurysm treatment. Sci Rep 2020; 10:6629. [PMID: 32313094 PMCID: PMC7170914 DOI: 10.1038/s41598-020-63574-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/01/2020] [Indexed: 11/09/2022] Open
Abstract
To evaluate artifact reduction by virtual monoenergetic images (VMI) and metal artifact reduction algorithms (MAR) as well as the combination of both approaches (VMIMAR) compared to conventional CT images (CI) as standard of reference. In this retrospective study, 35 patients were included who underwent spectral-detector CT (SDCT) with additional MAR-reconstructions due to artifacts from coils or clips. CI, VMI, MAR and VMIMAR (range: 100-200 keV, 10 keV-increment) were reconstructed. Region-of-interest based objective analysis was performed by assessing mean and standard deviation of attenuation (HU) in hypo- and hyperdense artifacts from coils and clips. Visually, extent of artifact reduction and diagnostic assessment were rated. Compared to CI, VMI ≥ 100 keV, MAR and VMIMAR between 100-200 keV increased attenuation in hypoattenuating artifacts (CI/VMI200keV/MAR/VMIMAR200keV, HU: -77.6 ± 81.1/-65.1 ± 103.2/-36.9 ± 27.7/-21.1 ± 26.7) and decreased attenuation in hyperattenuating artifacts (HU: 47.4 ± 32.3/42.1 ± 50.2/29.5 ± 18.9/20.8 ± 25.8). However, differences were only significant for MAR in hypodense and VMIMAR in hypo- and hyperdense artifacts (p < 0.05). Visually, hypo- and hyperdense artifacts were significantly reduced compared to CI by VMI≥140/100keV, MAR and VMIMAR≥100keV. Diagnostic assessment of surrounding brain tissue was significantly improved in VMI≥100keV, MAR and VMIMAR≥100keV. The combination of VMI and MAR facilitates a significant reduction of artifacts adjacent to intracranial coils and clips. Hence, if available, these techniques should be combined for optimal reduction of artifacts following intracranial aneurysm treatment.
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Affiliation(s)
- David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Else Kröner Forschungskolleg Clonal Evolution in Cancer, University Hospital Cologne, Weyertal 115b, 50931, Cologne, Germany
| | - Lenhard Pennig
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Andreas Glauner
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nuran Abdullayev
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Johannes Bremm
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nils Große Hokamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Thorsten Persigehl
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Christoph Kabbasch
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Jan Borggrefe
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Kai Roman Laukamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany. .,University Hospitals Cleveland Medical Center, Department of Radiology, Cleveland, OH, USA. .,Case Western Reserve University, Department of Radiology, Cleveland, OH, USA.
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10
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Laukamp KR, Große Hokamp N, Alabar O, Obmann VC, Lennartz S, Zopfs D, Gilkeson R, Ramaiya N, Gupta A. Metal artifacts from sternal wires: evaluation of virtual monoenergetic images from spectral-detector CT for artifact reduction. Clin Imaging 2020; 60:249-256. [DOI: 10.1016/j.clinimag.2019.12.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 12/22/2019] [Accepted: 12/27/2019] [Indexed: 10/25/2022]
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Lee KYG, Cheng HMJ, Chu CY, Tam CWA, Kan WK. Metal artifact reduction by monoenergetic extrapolation of dual-energy CT in patients with metallic implants. J Orthop Surg (Hong Kong) 2020; 27:2309499019851176. [PMID: 31138022 DOI: 10.1177/2309499019851176] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
PURPOSE The objective of this study is to assess artifact reduction and image quality using dual-energy computed tomography (DECT) and metal artifact reduction techniques in patients with metallic implants. METHODS Forty patients with metallic implants, who had targeted CT performed by DECT during March to September 2018, were prospectively recruited. Post-processing with monoenergetic extrapolation at 70 and 150 keV was performed. Forty matched controls with metallic implants with single-energy CT (SECT) performed were selected. Attenuation value, noise, and signal-to-noise ratio (SNR) at the site of maximal artifact were measured at muscle and fat areas. Image quality of three sets of images (70 keV, 150 keV, and SECT) was assessed by two independent reviewers using a 5-point Likert-type scale. Statistical analysis of measured values, Likert-type scales, and radiation doses (volume CT dose index (CTDIvol)) of DECT and SECT were performed with Mann-Whitney U test. RESULTS As compared to SECT, high keV reconstruction of DECT show (1) significantly higher values within muscle and fat surrounding the implant (DECT vs. SECT-muscle: -96 Hounsfield units (HU) vs. -405 HU, fat: -115 HU vs. -301 HU; p < 0.001), (2) significantly lower mean image noise (75 HU vs. 129 HU; p = 0.02), and (3) higher SNR (-0.8 vs. -4.3; p < 0.001). In addition, image quality of high keV reconstruction was rated superior to the other two groups on Likert-type scales ( p < 0.001). The mean radiation doses (CTDIvol) were comparable between DECT and SECT (14.2 mGy vs. 19.3 mGy; p = 0.08). CONCLUSION For patients with metallic implants, monoenergetic extrapolation of DECT at high keV can reduce metal artifacts, increase SNR, and improve qualitative image quality at comparable radiation dose.
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Affiliation(s)
- Ka Yin Gregory Lee
- 1 Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong
| | - Hei Man Joyce Cheng
- 1 Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong
| | - Chi Yeung Chu
- 1 Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong
| | - Chi Wai Annie Tam
- 1 Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong
| | - Wai Kuen Kan
- 1 Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong
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Is CT-based cinematic rendering superior to volume rendering technique in the preoperative evaluation of multifragmentary intraarticular lower extremity fractures? Eur J Radiol 2020; 126:108911. [PMID: 32171910 DOI: 10.1016/j.ejrad.2020.108911] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 01/07/2020] [Accepted: 02/16/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE Cinematic rendering (CR), a recently launched, FDA-approved rendering technique converts CT image datasets into nearly photorealistic 3D reconstructions by using a unique lighting model. The purpose of this study was to compare CR to volume rendering technique (VRT) images in the preoperative visualization of multifragmentary intraarticular lower extremity fractures. METHOD In this retrospective study, CT datasets of 41 consecutive patients (female: n = 13; male: n = 28; mean age: 52.3 ± 17.9y) with multifragmentary intraarticular lower extremity fractures (calcaneus: n = 16; tibial pilon: n = 19; acetabulum: n = 6) were included. All datasets were acquired using a 128-row dual-source CT. A dedicated workstation was used to reconstruct CR and VRT images which were reviewed independently by two experienced board-certified traumatologists trained in special trauma surgery. Image quality, anatomical accuracy and fracture visualization were assessed on a 6-point-Likert-scale (1 = non-diagnostic; 6=excellent). The regular CT image reconstructions served as reverence standard. For each score, median values between both readers were calculated. Scores of both reconstruction methods were compared using a Wilcoxon-Ranksum test with p < 0.05 indicating statistical significance. Inter-reader agreement was calculated using Spearman's rank correlation coefficient. RESULTS Compared to VRT, CR demonstrated a higher image quality (VRT:2.5; CR:6.0; p < 0.001), a higher anatomical accuracy (VRT:3.5; CR:5.5; p < 0.001) and provided a more detailed visualization of the fracture (VRT:2.5; CR:6.0; p < 0.001). An additional benefit of CR reconstructions compared to VRT reconstructions was reported by both readers in 65.9 % (27/41) of all patients. CONCLUSIONS CR reconstructions are superior to VRT due to higher image quality and higher anatomical accuracy. Traumatologists find CR reconstructions to improve visualization of lower extremity fractures which should thus be used for fracture demonstration during interdisciplinary conferences.
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Laukamp KR, Zopfs D, Wagner A, Lennartz S, Pennig L, Borggrefe J, Ramaiya N, Große Hokamp N. CT artifacts from port systems: Virtual monoenergetic reconstructions from spectral-detector CT reduce artifacts and improve depiction of surrounding tissue. Eur J Radiol 2019; 121:108733. [PMID: 31739270 DOI: 10.1016/j.ejrad.2019.108733] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 10/19/2019] [Accepted: 10/27/2019] [Indexed: 11/27/2022]
Abstract
PURPOSE CT artifacts from port-systems are a common problem in staging- and restaging-examinations and reduce image quality and diagnostic assessment. The purpose of this study was to investigate the reduction of these artifacts using virtual monoenergetic images (VMI) from dual-energy spectral-detector CT (SDCT) in comparison to conventional CT-images (CI). METHOD 50 SDCT-datasets of patients with artifacts from port-chamber and port-catheters were included in this IRB-approved, retrospective study. CI and VMI (range, 40-200 keV, 10 keV increment) were reconstructed from the same acquisition. The quantitative image analysis was performed ROI-based assessing mean and standard deviation of attenuation (HU) in most pronounced hypo- and hyperdense artifacts surrounding to the port-chamber and the distal end of the port-catheter in the superior vena cava. Subjectively, artifact reduction and diagnostic assessment of surrounding soft tissue were rated on 5-point Likert-scales. RESULTS In comparison to CI, VMI of higher keV-values showed strong reduction of hypo- and hyperattenuating artifacts around the port-chamber and port-catheter (CI/VMI200keV: hypodense -104.7 ± 124.7HU/10.8 ± 58.1HU and -101.6 ± 101.5HU/-36.7 ± 32.9HU; hyperdense 240.8 ± 151.6HU/79.6 ± 81.3HU and 108.6 ± 129.3HU/25.9 ± 31.9HU; all p < 0.001). Image noise could also be reduced significantly. The subjective analysis showed significantly reduced artifacts around the port-chamber and port-catheter (CI/VMI200keV: hypodense 3(1-4)/5(4-5) and 3(2-4)/5(4-5); hyperdense 3(1-4)/5(4-5) and 3(2-3)/5(3-5); all p < 0.001) and improved diagnostic assessment of pectoral/subclavian soft tissue for VMI of ≥100keV. Ratings for diagnostic assessment were best between 140-200 keV. Overall interrater agreement was high (ICC = 0.79). CONCLUSIONS Higher keV VMI enabled a significant reduction of artifacts from port-systems around the chamber and the catheter leading to improved assessment of surrounding soft tissue.
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Affiliation(s)
- Kai Roman Laukamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany; Department of Radiology, University Hospitals Cleveland Medical Center, 11000 Euclid Ave, 44106 Cleveland, OH, USA; Department of Radiology, Case Western Reserve University, 10900 Euclid Ave, 44106, Cleveland, OH, USA.
| | - David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Anton Wagner
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Lenhard Pennig
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Jan Borggrefe
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Nikhil Ramaiya
- Department of Radiology, University Hospitals Cleveland Medical Center, 11000 Euclid Ave, 44106 Cleveland, OH, USA; Department of Radiology, Case Western Reserve University, 10900 Euclid Ave, 44106, Cleveland, OH, USA
| | - Nils Große Hokamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany; Department of Radiology, University Hospitals Cleveland Medical Center, 11000 Euclid Ave, 44106 Cleveland, OH, USA; Department of Radiology, Case Western Reserve University, 10900 Euclid Ave, 44106, Cleveland, OH, USA
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Metal artifacts in patients with large dental implants and bridges: combination of metal artifact reduction algorithms and virtual monoenergetic images provides an approach to handle even strongest artifacts. Eur Radiol 2019; 29:4228-4238. [PMID: 30649598 DOI: 10.1007/s00330-018-5928-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/06/2018] [Accepted: 11/28/2018] [Indexed: 10/27/2022]
Abstract
OBJECTIVES This study compares reduction of strong metal artifacts from large dental implants/bridges using spectral detector CT-derived virtual monoenergetic images (VMI), metal artifact reduction algorithms/reconstructions (MAR), and a combination of both methods (VMIMAR) to conventional CT images (CI). METHODS Forty-one spectral detector CT (SDCT) datasets of patients that obtained additional MAR reconstructions due to strongest artifacts from large oral implants were included. CI, VMI, MAR, and VMIMAR ranging from 70 to 200 keV (10 keV increment) were reconstructed. Objective image analyses were performed ROI-based by measurement of attenuation (HU) and standard deviation in most pronounced hypo-/hyperdense artifacts as well as artifact impaired soft tissue (mouth floor/soft palate). Extent of artifact reduction, diagnostic assessment of soft tissue, and appearance of new artifacts were rated visually by two radiologists. RESULTS The hypo-/hyperattenuating artifacts showed an increase and decrease of HU values in MAR and VMIMAR (CI/MAR/VMIMAR-200keV: - 369.8 ± 239.6/- 37.3 ± 109.6/- 46.2 ± 71.0 HU, p < 0.001 and 274.8 ± 170.2/51.3 ± 150.8/36.6 ± 56.0, p < 0.001, respectively). Higher keV values in hyperdense artifacts allowed for additional artifact reduction; however, this trend was not significant. Artifacts in soft tissue were reduced significantly by MAR and VMIMAR. Visually, high-keV VMI, MAR, and VMIMAR reduced artifacts and improved diagnostic assessment of soft tissue. Overcorrection/new artifacts were reported that mostly did not hamper diagnostic assessment. Overall interrater agreement was excellent (ICC = 0.85). CONCLUSIONS In the presence of strong artifacts due to large oral implants, MAR is a powerful mean for artifact reduction. For hyperdense artifacts, MAR should be supplemented by VMI ranging from 140 to 200 keV. This combination yields optimal artifact reduction and improves the diagnostic image assessment in imaging of the head and neck. KEY POINTS • Large oral implants can cause strong artifacts. • MAR is a powerful tool for artifact reduction considering such strong artifacts. • Hyperdense artifact reduction is supplemented by VMI of 140-200 keV from SDCT.
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Reducing artifacts from total hip replacements in dual layer detector CT: Combination of virtual monoenergetic images and orthopedic metal artifact reduction. Eur J Radiol 2018; 111:14-20. [PMID: 30691660 DOI: 10.1016/j.ejrad.2018.12.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 12/05/2018] [Accepted: 12/06/2018] [Indexed: 11/23/2022]
Abstract
PURPOSE To evaluate the reduction of artifacts caused by total hip replacements (THR) in dual-layer DECT (DLCT) provided by the combination of virtual monoenergetic images (VMI) and orthopedic metal artifact reduction (MAR). MATERIALS AND METHODS A total of 24 consecutive patients carrying THR, who received DLCT, were included. Four different images were reconstructed from the same CT dataset: a) conventional images (CI), b) conventional images with orthopedic metal artifact reduction (CIMAR) c) VMI and d) VMI combined with orthopedic metal artifact reduction (VMIMAR). VMI and VMIMAR were reconstructed at 140 keV, 160 keV, 180 keV and 200 keV. Attenuation (HU) and noise (SD) were measured in order to evaluate reduction of hypodense and hyperdense artifacts, evaluate reduction of image noise as well as to calculate contrast-to-noise ratios (CNR). Image quality was additionally rated with regard to: a) extent of artifact reduction and assessment of b) pelvic organs, c) bone and d) muscle adjacent to the metal implants. Statistical analysis was performed using Wilcoxon test. RESULTS VMIMAR at high keV, 140, 160, 180 and 200 keV, led to the greatest reduction of hypodense artifacts in comparison to plain VMI or CIMAR (p < 0.01), while in comparison to CI hyperdense artifacts were significantly reduced in all reconstructions (p < 0.05). Accordingly, subjective analysis found VMIMAR to be superior in reducing hypodense artifacts in comparison to VMI and CIMAR (p < 0.05), while hyperdense artifacts were equally reduced in all reconstructions compared to CI (p < 0.0001). Additionally, assessment of the pelvic organs and adjacent bone was significantly improved in VMIMAR in comparison to VMI and CIMAR (p < 0.05). In contrast, muscles adjacent to the metal implants were significantly better assessable in all reconstructions compared to CI (p < 0.01). CONCLUSION The combination of VMI and MAR yields strongest reduction of hypo- and hyperdense artifacts caused by total hip replacements in staging DLCT in comparison to each technique by itself.
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Große Hokamp N, Laukamp K, Lennartz S, Zopfs D, Abdullayev N, Neuhaus V, Maintz D, Borggrefe J. Artifact reduction from dental implants using virtual monoenergetic reconstructions from novel spectral detector CT. Eur J Radiol 2018; 104:136-142. [DOI: 10.1016/j.ejrad.2018.04.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 03/31/2018] [Accepted: 04/18/2018] [Indexed: 11/27/2022]
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Perlepe V, Omoumi P, Larbi A, Putineanu D, Dubuc JE, Schubert T, Vande Berg B. Can we assess healing of surgically treated long bone fractures on radiograph? Diagn Interv Imaging 2018; 99:381-386. [DOI: 10.1016/j.diii.2018.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 02/12/2018] [Accepted: 02/16/2018] [Indexed: 11/27/2022]
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Laukamp KR, Lennartz S, Neuhaus VF, Große Hokamp N, Rau R, Le Blanc M, Abdullayev N, Mpotsaris A, Maintz D, Borggrefe J. CT metal artifacts in patients with total hip replacements: for artifact reduction monoenergetic reconstructions and post-processing algorithms are both efficient but not similar. Eur Radiol 2018; 28:4524-4533. [PMID: 29725834 DOI: 10.1007/s00330-018-5414-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 02/22/2018] [Accepted: 02/27/2018] [Indexed: 11/26/2022]
Abstract
OBJECTIVES This study compares metal artifact (MA) reduction in imaging of total hip replacements (THR) using virtual monoenergetic images (VMI), for MA-reduction-specialized reconstructions (MAR) and conventional CT images (CI) from detector-based dual-energy computed tomography (SDCT). METHODS Twenty-seven SDCT-datasets of patients carrying THR were included. CI, MAR and VMI with different energy-levels (60-200 keV) were reconstructed from the same scans. MA width was measured. Attenuation (HU), noise (SD) and contrast-to-noise ratio (CNR) were determined in: extinction artifact, adjacent bone, muscle and bladder. Two radiologists assessed MA-reduction and image quality visually. RESULTS In comparison to CI, VMI (200 keV) and MAR showed a strong artifact reduction (MA width: CI 29.9±6.8 mm, VMI 17.6±13.6 mm, p<0.001; MAR 16.5±14.9 mm, p<0.001; MA density: CI -412.1±204.5 HU, VMI -279.7±283.7 HU; p<0.01; MAR -116.74±105.6 HU, p<0.001). In strong artifacts reduction was superior by MAR. In moderate artifacts VMI was more effective. MAR showed best noise reduction and CNR in bladder and muscle (p<0.05), whereas VMI were superior for depiction of bone (p<0.05). Visual assessment confirmed that VMI and MAR improve artifact reduction and image quality (p<0.001). CONCLUSIONS MAR and VMI (200 keV) yielded significant MA reduction. Each showed distinct advantages both regarding effectiveness of artifact reduction, MAR regarding assessment of soft tissue and VMI regarding assessment of bone. KEY POINTS • Spectral-detector computed tomography improves assessment of total hip replacements and surrounding tissue. • Virtual monoenergetic images and MAR reduce metal artifacts and enhance image quality. • Evaluation of bone, muscle and pelvic organs can be improved by SDCT.
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Affiliation(s)
- Kai Roman Laukamp
- Department of Radiology, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Simon Lennartz
- Department of Radiology, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | | | - Nils Große Hokamp
- Department of Radiology, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Robert Rau
- Department of Radiology, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Markus Le Blanc
- Department of Radiology, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Nuran Abdullayev
- Department of Radiology, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Anastasios Mpotsaris
- Department of Radiology, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - David Maintz
- Department of Radiology, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Jan Borggrefe
- Department of Radiology, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany.
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Ballard DH, Trace AP, Ali S, Hodgdon T, Zygmont ME, DeBenedectis CM, Smith SE, Richardson ML, Patel MJ, Decker SJ, Lenchik L. Clinical Applications of 3D Printing: Primer for Radiologists. Acad Radiol 2018; 25:52-65. [PMID: 29030285 DOI: 10.1016/j.acra.2017.08.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 12/22/2022]
Abstract
Three-dimensional (3D) printing refers to a number of manufacturing technologies that create physical models from digital information. Radiology is poised to advance the application of 3D printing in health care because our specialty has an established history of acquiring and managing the digital information needed to create such models. The 3D Printing Task Force of the Radiology Research Alliance presents a review of the clinical applications of this burgeoning technology, with a focus on the opportunities for radiology. Topics include uses for treatment planning, medical education, and procedural simulation, as well as patient education. Challenges for creating custom implantable devices including financial and regulatory processes for clinical application are reviewed. Precedent procedures that may translate to this new technology are discussed. The task force identifies research opportunities needed to document the value of 3D printing as it relates to patient care.
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Metal artifact reduction by dual-layer computed tomography using virtual monoenergetic images. Eur J Radiol 2017; 93:143-148. [PMID: 28668408 DOI: 10.1016/j.ejrad.2017.05.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 05/09/2017] [Accepted: 05/11/2017] [Indexed: 01/27/2023]
Abstract
OBJECTIVE The aim of the study was to investigate the performance and diagnostic value of metal artifact reduction in virtual monoenergetic images generated from dual-layer computed tomography (DLCT). METHODS 35 patients that received a DLCT at the University Hospital Cologne and had an orthopedic implant in the examined region were included in this study. For each DLCT virtual monoenergetic images of different energy levels (64keV, 70keV, 105keV, 140keV, 200keV and an optimized photon energy) were reconstructed and analyzed by three blinded observers. Images were analyzed with regard to subjective criteria (extent of artifacts, diagnostic image quality) and objective criteria (width and density of artifacts). RESULTS 21 patients had implants in the spine, 8 in the pelvis and 6 patients in the extremities. Diagnostic image quality improved significantly at high photon energies from a Likert-score of 4.3 (±0.83) to 2.3 (±1.02) and artifacts decreased significantly from a score of 4.3 (±0.66) to 2.6 (±2.57). The average optimized photon energy was 149.2±39.4keV. The density as well as the width of the most pronounced artifacts decreased from-374.6±251.89HU to -12.5±205.84HU and from 14.5±8.74mm to 6.4±10.76mm, respectively. CONCLUSION Using virtual monoenergetic images valuable improvements of diagnostic image quality can be achieved by reduction of artifacts associated with metal implants. As preset for virtual monoenergetic images, 140keV appear to provide optimal artifact reduction. In 20% of the patients, individually optimized keV can lead to a further improvement of image quality compared to 140keV.
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Griffis CE, Olsen C, Nesti L, Gould CF, Frew M, McKay P. Validity of computed tomography in predicting scaphoid screw prominence: a cadaveric study. Arch Orthop Trauma Surg 2017; 137:573-577. [PMID: 28260129 DOI: 10.1007/s00402-017-2658-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Indexed: 11/25/2022]
Abstract
BACKGROUND Studies of hardware protrusion into joint spaces following fracture fixation have been performed to address whether or not there is discrepancy between the actual and radiographic appearance of screw prominence. The purpose of our study was to prove that, with respect to the scaphoid, prominence as visualized on CT scan is real and not a result of metal artifact. METHODS Forty-two cadaveric wrists were separated into four allotted groups with 21 control specimens and 21 study specimens. All specimens were radiographically screened to exclude those with inherent carpal abnormalities. Acutrak® headless compression screws were placed into all specimens using an open dorsal approach. Cartilage was removed from screw insertion site at the convex surface of the scaphoid proximal pole. Control specimens had 0 mm screw head prominence. The studied specimens had 1, 2, and 3 mm head prominence measured with a digital caliper. Computed tomography, with direct sagittal acquisition and metal suppression technique, was then performed on all specimens following screw placement. Two staff radiologists blinded to the study groups interpreted the images. RESULTS Results revealed that only one of 21 control specimens was interpreted as prominent. Comparatively, in the studied groups, 90% were accurately interpreted as prominent. CONCLUSIONS CT provides an accurate assessment of scaphoid screw head prominence. When a screw appears prominent on CT scan, it is likely to be truly prominent without contribution from metallic artifact.
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Affiliation(s)
- Clare E Griffis
- Captain James A. Lovell Federal Health Care Center, USS Tranquillity BHC 1007, 3001 Greenbay Road, North Chicago, IL, 60064, USA.
| | - Cara Olsen
- Biostatistics Consulting Center, Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
| | - Leon Nesti
- Walter Reed National Military Medical Center, Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
| | - C Frank Gould
- Walter Reed National Military Medical Center, Uniformed Services University, 8901 Rockville Pike, Bethesda, MD, 20889, USA
| | - Michael Frew
- Walter Reed National Military Medical Center, Uniformed Services University, 8901 Rockville Pike, Bethesda, MD, 20889, USA
| | - Patricia McKay
- Uniformed Services University of Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.,Orthopaedic Hand and Upper Extremity Surgery, Walter Reed National Military Medical Center, 8901, Rockville Pike, Bethesda, MD, 20889, USA.,Kimbrough Ambulatory Care Center, Fort Meade, MD, USA
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Wang H, Wang F, Newman S, Lin Y, Chen X, Xu L, Wang Q. Application of an innovative computerized virtual planning system in acetabular fracture surgery: A feasibility study. Injury 2016; 47:1698-701. [PMID: 27238885 DOI: 10.1016/j.injury.2016.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 05/03/2016] [Accepted: 05/07/2016] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Acetabular fracture surgery is amongst the most challenging tasks in the field of trauma surgery and careful preoperative planning is crucial for success. The aim of this paper is to describe the preliminary outcome of the utilization of an innovative computerized virtual planning system for acetabular fractures. METHODS 3D models of acetabular fractures and surrounding soft tissues from six patients were constructed from preoperative CT scans. A novel highly-automatic segmentation technique was performed on the 3D model to separate each fracture fragment, then 3D virtual reduction was performed. Additionally, the models were used to assess potential surgical approaches with reference to both the fracture and the surrounding soft tissues. The time required for virtual planning was recorded. After surgery, the virtual plan was compared to the real surgery with respect to surgical approach and reduction sequence. A Likert scale questionnaire was completed by the surgeons to evaluate their satisfaction with the system. RESULTS Virtual planning was successfully completed in all cases. The planned surgical approach was followed in all cases with the planned reduction sequence followed completely in five cases and partially in one. The mean time required for virtual planning was 38.7min (range 21-57, SD=15.5). The mean time required for planning of B-type fractures was 25.0min (range 21-30, SD=4.6), of C-type fracture 52.3min (range 49-57, SD=4.2). The results of the questionnaire demonstrated a high level of satisfaction with the planning system. CONCLUSION This study demonstrates that the virtual planning system is feasible in clinical settings with high satisfaction and acceptability from the surgeons. It provides a viable option for the planning of acetabular fracture surgery.
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Affiliation(s)
- Huixiang Wang
- Orthopaedic Traumatology, Trauma Center, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, PR China
| | - Fang Wang
- Orthopaedic Traumatology, Trauma Center, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, PR China
| | - Simon Newman
- MSk Lab, Imperial College London, Charing Cross Hospital, London, UK
| | - Yanping Lin
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, PR China
| | - Xiaojun Chen
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, PR China
| | - Lu Xu
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, PR China
| | - Qiugen Wang
- Orthopaedic Traumatology, Trauma Center, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, PR China.
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Digital Tomosynthesis to Evaluate Fracture Healing: Prospective Comparison With Radiography and CT. AJR Am J Roentgenol 2015; 205:136-41. [PMID: 26102392 DOI: 10.2214/ajr.14.13833] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Radiography, currently the standard for postoperative fracture imaging, is limited by overlapping bone and hardware. Tomosynthesis has the benefit of level-by-level imaging without the disadvantages of metal artifacts, increased radiation, and higher costs of CT, the current problem-solving tool. The purpose of this study was to compare tomosynthesis with radiography for evaluating fracture healing. SUBJECTS AND METHODS In a prospective study, patients within 1 year of wrist hardware fixation underwent radiography, tomosynthesis, and CT, and the images were interpreted by three readers. The diagnostic accuracy of radiology and tomosynthesis was assessed with ROC curves, and interreader agreement was assessed with Cohen kappa. Fracture scores were correlated with Disabilities of the Arm, Shoulder, and Hand (DASH) and pain scores. RESULTS The study participants were 49 patients with 51 fractures. The most common fracture sites were distal radius (43%), scaphoid (18%), and metacarpals (18%). Rates of cortex obscuration by hardware were 2% for CT, 8% for tomosynthesis, and 15% for radiography (p < 0.01 between one modality and another). Detection of cortical fracture lines was significantly better with tomosynthesis than with radiography (AUC, 0.84 vs 0.76, p = 0.01). Inter-reader agreement was moderate for both radiography and tomosynthesis (κ = 0.44 vs 0.55, p = 0.051). There was no significant correlation between fracture scores and DASH scores. There was significant correlation between reported pain levels and both tomosynthesis (r = 0.28, p = 0.03) and CT (r = 0.29, p = 0.04) fracture scores. CONCLUSION Tomosynthesis provides diagnostic information superior to that of ra diography in postoperative evaluation of wrist fractures with lower cost and radiation than CT and should be considered in fracture follow-up imaging of other bones.
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Khan MS, Rashid H, Umer M, Qadir I, Hafeez K, Iqbal A. Salvage of infected non-union of the tibia with an Ilizarov ring fixator. J Orthop Surg (Hong Kong) 2015; 23:52-5. [PMID: 25920644 DOI: 10.1177/230949901502300112] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
PURPOSE To review outcomes of 24 patients who underwent Ilizarov ring fixation for infected nonunion of the tibia. METHODS Medical records of 21 men and 3 women aged 13 to 74 (mean, 38) years who underwent Ilizarov ring fixation for infected non-union of the tibia were reviewed. The mean bone defect was 3.3 (range, 2-5) cm. The mean time from injury to presentation was 11.9 (range, 1-36) months. The mean number of previous surgeries was 2 (range, 0-14). A local flap was used in 2 patients and a free flap was used in one patient. Nine of the patients underwent Ilizarov ring fixation without soft tissue and bony resection, as inadequate stability was the reason for non-union. Patients were assessed using the Association for the Study and Application of the Method of Ilizarov criteria. RESULTS Patients were followed up for a mean of 11 (range, 8-46) months. Functional outcome was excellent in 8 patients, good in 12, fair in 2, and failure in one, whereas bone union outcome was excellent in 6 patients, good in 14, fair in one, and poor in 2. The mean time to union was 8 (range, 3-31) months. The mean external fixation index was 4.2 (range, 1.5-15.7) cm/month. Complications encountered were pin tract infection (n=5), re-fracture (n=2), soft tissue impingement by Ilizarov rings (n=2), recurrence of wound infection (n=1), mal-union (n=1), and mortality (n=1). CONCLUSION Ilizarov ring fixation is a viable option for infected non-union of the tibia. Adequate assessment of bone union is crucial before removal of fixator to prevent re-fracture.
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Affiliation(s)
- Muhammad Shahid Khan
- Department of Orthopaedic Surgery, Aga Khan University Hospital, Karachi, Pakistan
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Detection and Characterization of Tendon Abnormalities With Multidetector Computed Tomography. J Comput Assist Tomogr 2014; 38:299-307. [DOI: 10.1097/rct.0b013e3182aa72bf] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Soh E, Karmakar MK. Assessment of the spine with CT and MRI prior to interspinous/interlaminar spinal procedures: a pictorial review. Br J Radiol 2013; 86:20130066. [PMID: 23568363 DOI: 10.1259/bjr.20130066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Imaging of the spine is increasingly available, whether as dedicated spine examinations or as studies that include the spine in the images obtained (e.g. CT abdomen). This pictorial review discusses imaging of the spine with CT and MRI and how prior review of this imaging can be helpful with potentially difficult spinal procedures. Pathologies illustrated include osteoarthritis, scoliosis, inflammatory spondyloarthropathies and post-operative spines.
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Affiliation(s)
- E Soh
- Department of Radiology, Alexandra Hospital, Singapore.
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Lewis M, Reid K, Toms AP. Reducing the effects of metal artefact using high keV monoenergetic reconstruction of dual energy CT (DECT) in hip replacements. Skeletal Radiol 2013; 42:275-82. [PMID: 22684409 DOI: 10.1007/s00256-012-1458-6] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 05/21/2012] [Accepted: 05/22/2012] [Indexed: 02/02/2023]
Abstract
PURPOSE The aim of this study was to determine whether high keV monoenergetic reconstruction of dual energy computed tomography (DECT) could be used to overcome the effects of beam hardening artefact that arise from preferential deflection of low energy photons. MATERIALS AND METHODS Two phantoms were used: a Charnley total hip replacement set in gelatine and a Catphan 500. DECT datasets were acquired at 100, 200 and 400 mA (Siemens Definition Flash, 100 and 140 kVp) and reconstructed using a standard combined algorithm (1:1) and then as monoenergetic reconstructions at 10 keV intervals from 40 to 190 keV. Semi-automated segmentation with threshold inpainting was used to obtain the attenuation values and standard deviation (SD) of the streak artefact. High contrast line pair resolution and background noise were assessed using the Catphan 500. RESULTS Streak artefact is progressively reduced with increasing keV monoenergetic reconstructions. Reconstruction of a 400 mA acquisition at 150 keV results in reduction in the volume of streak artefact from 65 cm(3) to 17 cm(3) (74 %). There was a decrease in the contrast to noise ratio (CNR) at higher tube voltages, with the peak CNR seen at 70-80 keV. High contrast spatial resolution was maintained at high keV values. CONCLUSION Monoenergetic reconstruction of dual energy CT at increasing theoretical kilovoltages reduces the streak artefact produced by beam hardening from orthopaedic prostheses, accompanied by a modest increase in heterogeneity of background image attenuation, and decrease in contrast to noise ratio, but no deterioration in high contrast line pair resolution.
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Affiliation(s)
- Mark Lewis
- Norfolk and Norwich University Hospital, Norwich, UK.
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Johanson NA, Litrenta J, Zampini JM, Kleinbart F, Goldman HM. Surgical treatment options in patients with impaired bone quality. Clin Orthop Relat Res 2011; 469:2237-47. [PMID: 21384210 PMCID: PMC3126955 DOI: 10.1007/s11999-011-1838-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Bone quality should play an important role in decision-making for orthopaedic treatment options, implant selection, and affect ultimate surgical outcomes. The development of decision-making tools, currently typified by clinical guidelines, is highly dependent on the precise definition of the term(s) and the appropriate design of basic and clinical studies. This review was performed to determine the extent to which the issue of bone quality has been subjected to this type of process. QUESTIONS/PURPOSES We address the following issues: (1) current methods of clinically assessing bone quality; (2) emerging technologies; (3) how bone quality connects with surgical decision-making and the ultimate surgical outcome; and (4) gaps in knowledge that need to be closed to better characterize bone quality for more relevance to clinical decision-making. METHODS PubMed was used to identify selected papers relevant to our discussion. Additional sources were found using the references cited by identified papers. RESULTS Bone mineral density remains the most commonly validated clinical reference; however, it has had limited specificity for surgical decision-making. Other structural and geometric measures have not yet received enough study to provide definitive clinical applicability. A major gap remains between the basic research agenda for understanding bone quality and the transfer of these concepts to evidence-based practice. CONCLUSIONS Basic bone quality needs better definition through the systematic study of emerging technologies that offer a more precise clinical characterization of bone. Collaboration between basic scientists and clinicians needs to improve to facilitate the development of key questions for sound clinical studies.
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Affiliation(s)
- Norman A. Johanson
- Department of Orthopaedic Surgery, Drexel University College of Medicine, 245 N 15th Street, MS 420, Philadelphia, PA 19102 USA
| | - Jody Litrenta
- Drexel University College of Medicine, Philadelphia, PA USA
| | - Jay M. Zampini
- Department of Orthopaedic Surgery, Drexel University College of Medicine, 245 N 15th Street, MS 420, Philadelphia, PA 19102 USA
| | - Frederic Kleinbart
- Department of Orthopaedic Surgery, Drexel University College of Medicine, 245 N 15th Street, MS 420, Philadelphia, PA 19102 USA
| | - Haviva M. Goldman
- Department of Orthopaedic Surgery, Drexel University College of Medicine, 245 N 15th Street, MS 420, Philadelphia, PA 19102 USA ,Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA USA
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Magnetic resonance imaging of painful total hip replacement: detection and characterisation of periprosthetic fluid collection and interobserver reproducibility. Radiol Med 2011; 117:85-95. [DOI: 10.1007/s11547-011-0706-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 11/29/2010] [Indexed: 10/18/2022]
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Shapeero L, Poffyn B, De Visschere P, Sys G, Uyttendaele D, Vanel D, Forsyth R, Verstraete K. Complications of bone tumors after multimodal therapy. Eur J Radiol 2011; 77:51-67. [DOI: 10.1016/j.ejrad.2010.06.056] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 06/15/2010] [Indexed: 11/16/2022]
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Abstract
Multiple diagnostic imaging modalities are available and beneficial for the evaluation of the diabetic foot. There is not yet "one best test" for sorting out the diagnostic dilemmas commonly encountered. The differentiation of cellulitis alone from underlying osteomyelitis and the early detection of abscesses remain important diagnostic goals. Equally important, differentiation of osteomyelitis and neuroarthropathy remains a difficult job. This is often compounded by postoperative diabetic foot states status after reconstruction. Diagnostic evaluation often involves multiple studies that are complementary and that include conventional radiography, computed tomography, nuclear medicine scintigraphy, magnetic resonance imaging, ultrasonography, and positron emission tomography.
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Affiliation(s)
- Rebecca Loredo
- Department of Radiology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
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Abstract
Surgical complications of the calcaneus are unique to that structure but do not have a greater incidence than in any other part of the foot or ankle. The first tenet of any complication, however, is to recognize it. When all is said and done, recognition is probably the most important step when a complication arises.
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Affiliation(s)
- George F Wallace
- Podiatry Service, University Hospital - University of Medicine and Dentistry of New Jersey, 150 Bergen Street, G-142, Newark, NJ 07103, USA.
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Brattwall M, Turan I, Jakobsson J. Pain management after elective hallux valgus surgery: a prospective randomized double-blind study comparing etoricoxib and tramadol. Anesth Analg 2010; 111:544-9. [PMID: 20584877 DOI: 10.1213/ane.0b013e3181e3d87c] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Pain is a common complaint after day surgery, and there is still a controversy surrounding the use of selective cyclooxygenase-2 (COX-2) inhibitors. In the present prospective, randomized, double-blind study we compared pain management with a selective (COX-2) inhibitor (etoricoxib) with pain management using sustained-release tramadol after elective hallux valgus surgery. METHODS One hundred ASA 1 to 2 female patients were randomized into 2 groups of 50 patients each; oral etoricoxib 120 mg x 1 x IV + 90 mg x 1 x day V-VII and oral tramadol sustained-release 100 mg x 2 x VII. Pain, pain relief, satisfaction with pain management, and need for rescue medication were evaluated during the first 7 postoperative days. A computed tomography scan evaluating bone healing was performed 12 weeks after surgery. A clinical evaluation of outcome (healing, mobility, and patient-assessed satisfaction) was performed 16 weeks after surgery. RESULTS Two patients withdrew before discharge from the hospital. Ninety-eight patients, 81 ASA 1 and 17 ASA 2 (82 nonsmokers and 14 smokers), mean age 49 years (19-65), weight 64 (47-83) kg, and height 167 (154-183) cm were evaluated. Overall pain was well managed, but the mean visual analog scale (VAS) was significantly lower among etoricoxib patients evaluated during the entire 7-day period studied (12.5 + or - 8.3 vs. 17.3 + or - 11, P < 0.05). patient's grading of pain relief (92 + or - 12 vs. 85 + or - 15, P < 0.05) and satisfaction with pain medication (47/49 vs. 39/49, P < 0.05) was higher among etoricoxib patients. Patients receiving tramadol reported significantly more side effects. Six patients, all in the tramadol group, discontinued the study because of side effects (P < 0.05). At 14-day follow-up 1 patient in the etoricoxib group and 5 patients in the tramadol group exhibited minor irritation in the wound area. The 12-week computed tomography scan showed good healing in 82 patients, 43 in the etoricoxib group, and 39 in the tramadol group. The study found ongoing healing in 11 patients, 4 in the etoricoxib group and 7 in the tramadol group. The 16-week patient-assessed Health Profile Quality of life revealed high patient satisfaction overall; 47 patients in each study group rated the outcome as satisfactory and the mean change in the patient-assessed quality of life VAS score was 6.2 and 2.6 for the etoricoxib and tramadol groups, respectively. Clinical follow-up at 16 weeks showed high functionality and no signs or symptoms of improper healing in any patient. CONCLUSION Etoricoxib was found to be more effective and associated with fewer side effects in comparison with tramadol sustained release as a component of multimodel analgesia after elective hallux valgus surgery. There were no signs of impaired wound or bone healing associated with the use of etoricoxib.
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Affiliation(s)
- Metha Brattwall
- Foot & Ankle Surgical Centre, Storängsvägen 10, 11542 Stockholm, Sweden
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