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- Booij, Ronald, et al.
(författare)
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Assessment of visibility of bone structures in the wrist using normal and half of the radiation dose with photon-counting detector CT
- 2023
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Ingår i: European Journal of Radiology. - : ELSEVIER IRELAND LTD. - 0720-048X .- 1872-7727. ; 159
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To quantitatively and qualitatively assess the visibility of bone structures in the wrist on photon-counting detector computed tomography (PCD-CT) images compared to state-of-the-art energy-integrating de-tector CT (EID-CT).Method: Four human cadaveric wrist specimens were scanned with EID-CT and PCD-CT at identical CTDIvolof 12.2 mGy and with 6.1 mGy (half dose PCD-CT). Axial images were reconstructed using the thinnest possible slice thickness, i.e. 0.4 mm on EID-CT and 0.2 mm on PCD-CT, with the largest image matrix size possible using reconstruction kernels optimized for bone (EID-CT: Ur68, PCD-CT: Br92). Quantitative evaluation was performed to determine contrast-noise ratio (CNR) of bone/ fat, cortical and trabecular sharpness. An observer study using visual grading characteristics (VGC) analysis was performed by six observers to assess the visibility of nutrient canals, trabecular architecture, cortical bone and the general image quality.Results: At equal dose, images obtained with PCD-CT had 39 +/- 6 % lower CNR (p = 0.001), 71 +/- 57 % higher trabecular sharpness in the radius (p = 0.02) and 42 +/- 8 % (p < 0.05) sharper cortical edges than those obtained with EID-CT. This was confirmed by VGC analysis showing a superior visibility of nutrient canals, trabeculae and cortical bone area under the curve (AUC) > 0.89) for PCD-CT, even at half dose.Conclusions: Despite a lower CNR and increased noise, the trabecular and cortical sharpness were twofold higher with PCD-CT. Visual grading analysis demonstrated superior visibility of cortical bone, trabeculae, nutrient canals and an overall improved image quality with PCD-CT over EID-CT. At half dose, PCD-CT also yielded superior image quality, both in quantitative measures and as evaluated by radiologists.
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| 3. |
- Fredäng Kämmerling, Nina, et al.
(författare)
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A comparative study of image quality and diagnostic confidence in diagnosis and follow-up of scaphoid fractures using photon-counting detector CT and energy-integrating detector CT
- 2024
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Ingår i: European Journal of Radiology. - : ELSEVIER IRELAND LTD. - 0720-048X .- 1872-7727. ; 173
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Scaphoid fractures in patients and assessment of healing using PCD-CT have, as far as we know, not yet been studied. Therefore, the aim was to compare photon counting detector CT (PCD-CT) with energy integrating detector CT (EID-CT) in terms of fracture visibility and evaluation of fracture healing. Method: Eight patients with scaphoid fracture were examined with EID-CT and PCD-CT within the first week posttrauma, and with additional scans at 4, 6 and 8 weeks. Our clinical protocol for wrist examination with EID-CT was used (CTDIvol 3.1 +/- 0.1 mGy, UHR kernel Ur77). For PCD-CT matched radiation dose, reconstruction kernel Br89. Quantitative analyses of noise, CNR, trabecular and cortical sharpness, and bone volume fraction were conducted. Five radiologists evaluated the images for fracture visibility, fracture gap consolidation and image quality, and rated their confidence in the diagnosis. Results: The trabecular and cortical sharpness were superior in images obtained with PCD-CT compared with EIDCT. A successive reduction in trabecular bone volume fraction during the immobilized periods was found with both systems. Despite higher noise and lower CNR with PCD-CT, radiologists rated the image quality of PCD-CT as superior. The visibility of the fracture line within 1 -week post -trauma was rated higher with PCD-CT as was diagnostic confidence, but the subsequent assessments of fracture gap consolidation during healing process and the confidence in diagnosis were found equivalent between both systems. Conclusion: PCD-CT offers superior visibility of bone microstructure compared with EID-CT. The evaluation of fracture healing and confidence in diagnosis were rated equally with both systems, but the radiologists found primary fracture visibility and overall image quality superior with PCD-CT.
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| 4. |
- Mourad, Charbel, et al.
(författare)
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Chances and challenges of photon-counting CT in musculoskeletal imaging
- 2024
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Ingår i: Skeletal Radiology. - : SPRINGER. - 0364-2348 .- 1432-2161.
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Forskningsöversikt (refereegranskat)abstract
- In musculoskeletal imaging, CT is used in a wide range of indications, either alone or in a synergistic approach with MRI. While MRI is the preferred modality for the assessment of soft tissues and bone marrow, CT excels in the imaging of high-contrast structures, such as mineralized tissue. Additionally, the introduction of dual-energy CT in clinical practice two decades ago opened the door for spectral imaging applications. Recently, the advent of photon-counting detectors (PCDs) has further advanced the potential of CT, at least in theory. Compared to conventional energy-integrating detectors (EIDs), PCDs provide superior spatial resolution, reduced noise, and intrinsic spectral imaging capabilities. This review briefly describes the technical advantages of PCDs. For each technical feature, the corresponding applications in musculoskeletal imaging will be discussed, including high-spatial resolution imaging for the assessment of bone and crystal deposits, low-dose applications such as whole-body CT, as well as spectral imaging applications including the characterization of crystal deposits and imaging of metal hardware. Finally, we will highlight the potential of PCD-CT in emerging applications, underscoring the need for further preclinical and clinical validation to unleash its full clinical potential.
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| 5. |
- Woisetschläger, Mischa, et al.
(författare)
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Improved visualization of the bone-implant interface and osseointegration in ex vivo acetabular cup implants using photon-counting detector CT
- 2023
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Ingår i: EUROPEAN RADIOLOGY EXPERIMENTAL. - : SPRINGERNATURE. - 2509-9280. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundSuccessful osseointegration of joint replacement implants is required for long-term implant survival. Accurate assessment of osseointegration could enable clinical discrimination of failed implants from other sources of pain avoiding unnecessary surgeries. Photon-counting detector computed tomography (PCD-CT) provides improvements in image resolution compared to conventional energy-integrating detector CT (EID-CT), possibly allowing better visualization of bone-implant-interfaces and osseointegration. The aim of this study was to assess the quality of visualization of bone-implant-interfaces and osseointegration in acetabular cup implants, using PCD-CT compared with EID-CT.MethodsTwo acetabular implants (one cemented, one uncemented) retrieved during revision surgery were scanned using PCD-CT and EID-CT at equal radiation dose. Images were reconstructed using different reconstruction kernels and iterative strengths. Delineation of the bone-implant and bone-cement-interface as an indicator of osseointegration was scored subjectively for image quality by four radiologists on a Likert scale and assessed quantitatively.ResultsDelineation of bone-implant and bone-cement-interfaces was better with PCD-CT compared with EID-CT (p <= 0.030). The highest ratings were given for PCD-CT at sharper kernels for the cemented cup (PCD-CT, median 5, interquartile range 4.25-5.00 versus EID-CT, 3, 2.00-3.75, p < 0.001) and the uncemented cup (5, 4.00-5.00 versus 2, 2-2, respectively, p < 0.001). The bone-implant-interface was 35-42% sharper and the bone-cement-interface was 28-43% sharper with PCD-CT compared with EID-CT, depending on the reconstruction kernel.ConclusionsPCD-CT might enable a more accurate assessment of osseointegration of orthopedic joint replacement implants.
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