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Horst KK, Cao JY, McCollough CH, El-Ali A, Frush DP, Siegel MJ, Ramirez-Giraldo JC, O'Donnell T, Bach S, Yu L. Multi-institutional Protocol Guidance for Pediatric Photon-counting CT. Radiology 2024; 311:e231741. [PMID: 38771176 DOI: 10.1148/radiol.231741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Performing CT in children comes with unique challenges such as greater degrees of patient motion, smaller and densely packed anatomy, and potential risks of radiation exposure. The technical advancements of photon-counting detector (PCD) CT enable decreased radiation dose and noise, as well as increased spatial and contrast resolution across all ages, compared with conventional energy-integrating detector CT. It is therefore valuable to review the relevant technical aspects and principles specific to protocol development on the new PCD CT platform to realize the potential benefits for this population. The purpose of this article, based on multi-institutional clinical and research experience from pediatric radiologists and medical physicists, is to provide protocol guidance for use of PCD CT in the imaging of pediatric patients.
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Affiliation(s)
- Kelly K Horst
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
| | - Joseph Y Cao
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
| | - Cynthia H McCollough
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
| | - Alex El-Ali
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
| | - Donald P Frush
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
| | - Marilyn J Siegel
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
| | - Juan Carlos Ramirez-Giraldo
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
| | - Tom O'Donnell
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
| | - Steve Bach
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
| | - Lifeng Yu
- From the Department of Radiology, Division of Pediatric Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 (K.K.H., C.H.M., L.Y.); Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham, NC (J.Y.C., D.P.F., S.B.); Department of Radiology, Division of Pediatric Radiology, NYU Grossman School of Medicine, New York, NY (A.E.A.); Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (M.J.S.); and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G., T.O.)
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Kawamoto K, Sato H, Kogure Y. Usefulness of Ag Additional Filter on Image Quality and Radiation Dose for Low-Dose Chest Computed Tomography. J Comput Assist Tomogr 2024; 48:236-243. [PMID: 37551143 DOI: 10.1097/rct.0000000000001538] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
OBJECTIVE This study aimed to evaluate the effect of a silver (Ag) additional filter on dose characteristics and image quality in low-dose chest computed tomography (CT). METHODS A dose evaluation phantom, physical evaluation phantom, and chest phantom were scanned with and without an Ag additional filter. The doses were adjusted so that the displayed the volume CT dose indexes (CTDI vol ) were from 0.3 to 1.6 mGy. For dose characteristics, the spectrum of photon energies and the measured CTDI vol were calculated for each scanning condition. For task-based image quality analysis, task transfer function, noise power spectrum, and system performance were evaluated. Streak artifacts, image noise, and contrast-to-noise ratio were quantified using a chest phantom. RESULTS With the Ag additional filter, mean energy was 22% higher and the CTDI vol was approximately 30% lower than those without the Ag additional filter. The task transfer function and noise power spectrum with the Ag additional filter were lower than those without the Ag additional filter. The system performance with the Ag additional filter was similar to that without the Ag additional filter. The Ag additional filter reduced streak artifact near the lung apex and image noise in the lung fields. The contrast-to-noise ratio was slightly higher with the Ag additional filter than that without the Ag additional filter. CONCLUSIONS The output dose and spatial resolution with the Ag additional filter were lower than those without the Ag additional filter. However, this filter helped reduce the radiation dose, image noise, and streak artifacts, particularly when scanning at ultralow doses.
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Affiliation(s)
- Keishin Kawamoto
- From the Department of Radiological Technology, Juntendo University Hospital, Tokyo, Japan
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Horst KK, Yu L, McCollough CH, Esquivel A, Thorne JE, Rajiah PS, Baffour F, Hull NC, Weber NM, Thacker PG, Thomas KB, Binkovitz LA, Guerin JB, Fletcher JG. Potential benefits of photon counting detector computed tomography in pediatric imaging. Br J Radiol 2023; 96:20230189. [PMID: 37750939 PMCID: PMC10646626 DOI: 10.1259/bjr.20230189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/27/2023] Open
Abstract
Photon counting detector (PCD) CT represents the newest advance in CT technology, with improved radiation dose efficiency, increased spatial resolution, inherent spectral imaging capabilities, and the ability to eliminate electronic noise. Its design fundamentally differs from conventional energy integrating detector CT because photons are directly converted to electrical signal in a single step. Rather than converting X-rays to visible light and having an output signal that is a summation of energies, PCD directly counts each photon and records its individual energy information. The current commercially available PCD-CT utilizes a dual-source CT geometry, which allows 66 ms cardiac temporal resolution and high-pitch (up to 3.2) scanning. This can greatly benefit pediatric patients by facilitating high quality fast scanning to allow sedation-free imaging. The energy-resolving nature of the utilized PCDs allows "always-on" dual-energy imaging capabilities, such as the creation of virtual monoenergetic, virtual non-contrast, virtual non-calcium, and other material-specific images. These features may be combined with high-resolution imaging, made possible by the decreased size of individual detector elements and the absence of interelement septa. This work reviews the foundational concepts associated with PCD-CT and presents examples to highlight the benefits of PCD-CT in the pediatric population.
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Affiliation(s)
- Kelly K. Horst
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Lifeng Yu
- Department of Radiology, Mayo Clinic, Rochester, United States
| | | | - Andrea Esquivel
- Department of Radiology, Mayo Clinic, Rochester, United States
| | | | | | - Francis Baffour
- Department of Radiology, Mayo Clinic, Rochester, United States
| | - Nathan C. Hull
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | | | - Paul G. Thacker
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Kristen B. Thomas
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Larry A. Binkovitz
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Julie B. Guerin
- Department of Radiology, Mayo Clinic, Rochester, United States
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Tsiflikas I, Thater G, Ayx I, Weiss J, Schaefer J, Stein T, Schoenberg SO, Weis M. Low dose pediatric chest computed tomography on a photon counting detector system - initial clinical experience. Pediatr Radiol 2023; 53:1057-1062. [PMID: 36635378 DOI: 10.1007/s00247-022-05584-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 11/23/2022] [Accepted: 12/23/2022] [Indexed: 01/14/2023]
Abstract
BACKGROUND With the clinical release of a photon counting detector-based computed tomography (CT) system, the potential benefits of this new technology need to be evaluated clinically. Literature concerning this new generation of detector is sparse, especially in the field of pediatric radiology. Therefore, this study outlines our initial experience with ultra-low dose chest CT imaging on the new photon counting CT system. MATERIALS AND METHODS A pediatric phantom (1-year old, CIRS ATOM phantom, model 704 [CIRS-computerized imaging reference system, Norfolk, VA]) was scanned at different dose levels and different image quality levels to define a protocol for clinical examinations. Next, 20 consecutive pediatric non-contrast ultra-low dose chest CT examinations were evaluated for radiation dose and diagnostic image quality using a 4-point Likert-scale-1 = excellent, 4 = bad image quality-by two radiologists in a consensus reading. This retrospective analysis was approved by the local research ethics committee. RESULTS Chest CT examinations performed at ultra-low radiation dose (effective dose 0.19 ± 0.07 mSv; size-specific dose estimate 0.45 ± 0.14 mGy) in pediatric patients ages (2.6 ± 1.8 years) show good to excellent image quality for lung structures (1.4 ± 0.4) and moderate image quality for soft tissue structures (2.8 ± 0.2). CONCLUSION Pediatric ultra-low dose chest CT examinations are feasible with the new generation photon counting detector-based CT system. The benefits of this technology must be evaluated for pediatric patients from the outset.
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Affiliation(s)
- Ilias Tsiflikas
- Department of Diagnostic and Interventional Radiology, University Hospital, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Greta Thater
- Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Isabelle Ayx
- Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Jakob Weiss
- Department of Radiology, Freiburg University Hospital, Freiburg, Germany
| | - Juergen Schaefer
- Department of Diagnostic and Interventional Radiology, University Hospital, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Thomas Stein
- Department of Radiology, Freiburg University Hospital, Freiburg, Germany
| | - Stefan O Schoenberg
- Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Meike Weis
- Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
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Hasegawa A, Ichikawa K, Morioka Y, Kawashima H. A tin filter's dose reduction effect revisited: Using the detectability index in low-dose computed tomography for the chest. Phys Med 2022; 99:61-67. [PMID: 35623206 DOI: 10.1016/j.ejmp.2022.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/30/2022] [Accepted: 05/15/2022] [Indexed: 10/18/2022] Open
Abstract
PURPOSE To reevaluate a tin filter's (TF) dose reduction effect in computed tomography (CT) using a combination of an anthropomorphic chest phantom and a rod-shaped phantom. METHODS AND MATERIALS A third-generation dual-source CT system equipped with a built-in TF was employed. A chest phantom was scanned under low-dose conditions of 0.2 to 1.0 mGy with the TF at 100 kV (TF100kV) and without it at 100 kV and 120 kV (NF100kV and NF120kV). To eliminate effects other than that of the TF, only filtered back projection (FBP) was used for image reconstruction. On the images of the rod phantom placed inside the lung field, the CT number and the spatial resolution using the modulation transfer function (MTF) were measured. Using these indices plus the noise power spectrum (NPS) that was also measured, the detectability index based on the non-prewhitening model observer (d'NPW) was calculated. RESULTS The CT numbers and MTFs were almost identical across the three conditions. The area under the NPS curve was decreased by 13-17% with the TF compared with non-TF conditions. NPS increases at low frequencies of < 0.06 mm-1 observed in NF120kV and NF100kV were eliminated by TF100kV. The potential dose reduction by the TF, estimated using the d'NPW values, turned out to be 22 to 25%. CONCLUSION Based on the analysis of the FBP images of a chest phantom, the dose reduction attributable only to the TF was estimated at 22-25%, notably lower than those reported in previous studies.
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Affiliation(s)
- Akira Hasegawa
- Department of Radiological Technology, Faculty of Medical Technology, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata 950-3198, Japan; Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
| | - Katsuhiro Ichikawa
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
| | - Yusuke Morioka
- Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan; Department of Radiology, Toyama Prefectural Central Hospital, 2-2-78, Nishinagae, Toyama-shi, Toyama 930-8550, Japan.
| | - Hiroki Kawashima
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
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Gassenmaier S, Winkelmann MT, Magnus JP, Brendlin AS, Walter SS, Afat S, Artzner C, Nikolaou K, Bongers MN. Low-Dose CT for Renal Calculi Detection Using Spectral Shaping of High Tube Voltage. ROFO-FORTSCHR RONTG 2022; 194:1012-1019. [PMID: 35272363 DOI: 10.1055/a-1752-0472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE To investigate reduction of radiation exposure in unenhanced CT in suspicion of renal calculi using a tin-filtered high tube voltage protocol compared to a standard low-dose protocol without spectral shaping. MATERIALS AND METHODS A phantom study using 7 human renal calculi was performed to test both protocols. 120 consecutive unenhanced CT examinations performed due to suspicion of renal calculi were included in this retrospective, monocentric study. 60 examinations were included with the standard-dose protocol (SP) (100 kV/130 mAs), whereas another 60 studies were included using a low-dose protocol (LD) applying spectral shaping with tin filtration of high tube voltages (Sn150 kV/80 mAs). Image quality was assessed by two radiologists in consensus blinded to technical parameters using an equidistant Likert scale ranging from 1-5 with 5 being the highest score. Quantitative image quality was assessed using regions of interest in abdominal organs, muscles, and adipose tissue to analyze image noise and signal-to-noise ratios (SNR). Commercially available dosimetry software was used to determine and compare effective dose (ED) and size-specific dose estimates (SSDEmean). RESULTS All seven renal calculi of the phantom could be detected with both protocols. There was no difference regarding calcluli size between the two protocols except for the smallest one. The smallest concretion measured 1.5 mm in LD and 1.0 mm in SP (ground truth 1.5 mm). CTDIvol was 3.36 mGy in LD (DLP: 119.3 mGycm) and 8.27 mGy in SP (DLP: 293.6 mGycm). The mean patient age in SP was 47 ± 17 years and in LD 49 ± 13 years. Ureterolithiasis was found in 33 cases in SP and 32 cases in LD. The median concretion size was 3 mm in SP and 4 mm in LD. The median ED in LD was 1.3 mSv (interquartile range (IQR) 0.3 mSv) compared to 2.3 mSv (IQR 0.9 mSv) in SP (p < 0.001). The SSDEmean of LD was also significantly lower compared to SP with 2.4 mGy (IQR 0.4 mGy) vs. 4.8 mGy (IQR 2.3 mGy) (p < 0.001). The SNR was significantly lower in LD compared to SP (p < 0.001). However, there was no significant difference between SP and LD regarding the qualitative assessment of image quality with a median of 4 (IQR 1) for both groups (p = 0.648). CONCLUSION Tin-filtered unenhanced abdominal CT for the detection of renal calculi using high tube voltages leads to a significant reduction of radiation exposure and yields high diagnostic image quality without a significant difference compared to the institution's standard of care low-dose protocol without tin filtration. KEY POINTS · Tin-filtered CT for the detection of renal calculi significantly reduces radiation dose.. · The application of tin filtration provides comparable diagnostic image quality to that of SP protocols.. · An increase in image noise does not hamper diagnostic image quality.. CITATION FORMAT · Gassenmaier S, Winkelmann MT, Magnus J et al. Low-Dose CT for Renal Calculi Detection Using Spectral Shaping of High Tube Voltage. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1752-0472.
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Affiliation(s)
- Sebastian Gassenmaier
- Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Germany
| | - Moritz T Winkelmann
- Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Germany
| | - Jan-Philipp Magnus
- Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Germany
| | - Andreas Stefan Brendlin
- Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Germany
| | - Sven S Walter
- Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Germany.,Department of Radiology, Division of Musculoskeletal Radiology, NYU Grossman School of Medicine, New York
| | - Saif Afat
- Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Germany
| | - Christoph Artzner
- Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Germany
| | - Konstantin Nikolaou
- Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Germany
| | - Malte Niklas Bongers
- Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Germany
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Zhang J, Liu M, Liu D, Li X, Lin M, Tan Y, Luo Y, Zeng X, Yu H, Shen H, Wang X, Liu L, Tan Y, Zhang J. Low-dose CT with tin filter combined with iterative metal artefact reduction for guiding lung biopsy. Quant Imaging Med Surg 2022; 12:1359-1371. [PMID: 35111630 DOI: 10.21037/qims-21-555] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 10/08/2021] [Indexed: 12/24/2022]
Abstract
Background Computed tomography (CT) is currently the imaging modality of choice for guiding pulmonary percutaneous procedures. The use of a tin filter allows low-energy photons to be absorbed which contribute little to image quality but increases the radiation dose that a patient receives. Iterative metal artefact reduction (iMAR) was developed to diminish metal artefacts. This study investigated the impact of using tin filtration combined with an iMAR algorithm on dose reduction and image quality in CT-guided lung biopsy. Methods Ninety-nine consecutive patients undergoing CT-guided lung biopsy were randomly assigned to routine-dose CT protocols (groups A and B; without and with iMAR, respectively) or tin filter CT protocols (groups C and D; without or with iMAR, respectively). Subjective image quality was analysed using a 5-point Likert scale. Objective image quality was assessed, and the noise, contrast-to-noise ratio, and figure of merit were compared among the four groups. Metal artefacts were quantified using CT number reduction and metal diameter blurring. The radiation doses, diagnostic performance, and complication rates were also estimated. Results The subjective image quality of the two scan types was compared. Images with iMAR reconstruction were superior to those without iMAR reconstruction (group A: 3.49±0.65 vs. group B: 4.63±0.57; P<0.001, and group C: 3.88±0.66 vs. group D: 4.82±0.39; P<0.001). Images taken with a tin filter were found to have a significantly higher figure-of-merit than those taken without a tin filter (group A: 14,041±7,230 vs. group C: 21,866±10,656; P=0.001, and group B: 13,836±6,849 vs. group D: 21,639±9,964; P=0.001). In terms of metal artefact reduction, tin filtration combined with iMAR showed the lowest CT number reduction (116.62±103.48 HU) and metal diameter blurring (0.85±0.30) among the protocols. The effective radiation dose in the tin filter groups was 73.2% lower than that in the routine-dose groups. The complication rate and diagnostic performance (sensitivity, specificity, and overall accuracy) did not differ significantly between the tin filter and routine-dose groups (all P>0.05). Conclusions Tin filtration combined with an iMAR algorithm may reduce the radiation dose compared to the routine-dose CT protocol, while maintaining comparable diagnostic accuracy and image quality and producing fewer metal artefacts.
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Affiliation(s)
- Jing Zhang
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Meiling Liu
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Daihong Liu
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Xiaoqin Li
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Meng Lin
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Yong Tan
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Yuesheng Luo
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Xiangfei Zeng
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Hong Yu
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Hesong Shen
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Xiaoxia Wang
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Leilei Liu
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Yuchuan Tan
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
| | - Jiuquan Zhang
- Department of Radiology, Chongqing University Cancer Hospital, Chongqing, China
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Comparison of 100-Kilovoltage Tin Filtration With Advanced Modeled Iterative Reconstruction Protocol to an Automated Kilovoltage Selection With Filtered Back Projection Protocol on Radiation Dose and Image Quality in Pediatric Noncontrast-Enhanced Chest Computed Tomography. J Comput Assist Tomogr 2021; 46:64-70. [DOI: 10.1097/rct.0000000000001248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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