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Feldle P, Grunz JP, Kunz AS, Pannenbecker P, Patzer TS, Pichlmeier S, Sauer ST, Hendel R, Ergün S, Bley TA, Huflage H. Influence of spectral shaping and tube voltage modulation in ultralow-dose computed tomography of the abdomen. BMC Med Imaging 2024; 24:49. [PMID: 38395772 PMCID: PMC10893640 DOI: 10.1186/s12880-024-01228-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 02/14/2024] [Indexed: 02/25/2024] Open
Abstract
PURPOSE Unenhanced abdominal CT constitutes the diagnostic standard of care in suspected urolithiasis. Aiming to identify potential for radiation dose reduction in this frequent imaging task, this experimental study compares the effect of spectral shaping and tube voltage modulation on image quality. METHODS Using a third-generation dual-source CT, eight cadaveric specimens were scanned with varying tube voltage settings with and without tin filter application (Sn 150, Sn 100, 120, 100, and 80 kVp) at three dose levels (3 mGy: standard; 1 mGy: low; 0.5 mGy: ultralow). Image quality was assessed quantitatively by calculation of signal-to-noise ratios (SNR) for various tissues (spleen, kidney, trabecular bone, fat) and subjectively by three independent radiologists based on a seven-point rating scale (7 = excellent; 1 = very poor). RESULTS Irrespective of dose level, Sn 100 kVp resulted in the highest SNR of all tube voltage settings. In direct comparison to Sn 150 kVp, superior SNR was ascertained for spleen (p ≤ 0.004) and kidney tissue (p ≤ 0.009). In ultralow-dose scans, subjective image quality of Sn 100 kVp (median score 3; interquartile range 3-3) was higher compared with conventional imaging at 120 kVp (2; 2-2), 100 kVp (1; 1-2), and 80 kVp (1; 1-1) (all p < 0.001). Indicated by an intraclass correlation coefficient of 0.945 (95% confidence interval: 0.927-0.960), interrater reliability was excellent. CONCLUSIONS In abdominal CT with maximised dose reduction, tin prefiltration at 100 kVp allows for superior image quality over Sn 150 kVp and conventional imaging without spectral shaping.
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Affiliation(s)
- Philipp Feldle
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Andreas Steven Kunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Pauline Pannenbecker
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Theresa Sophie Patzer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Svenja Pichlmeier
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Stephanie Tina Sauer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Robin Hendel
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Süleyman Ergün
- Institute of Anatomy and Cell Biology, University of Würzburg, Koellikerstraße 6, 97070, Würzburg, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany.
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Oshima Y, Ohno Y, Takenaka D, Ito Y, Kimata H, Fujii K, Akino N, Hamabuchi N, Matsuyama T, Nagata H, Ueda T, Ikeda H, Ozawa Y, Yoshikawa T, Toyama H. Capability for dose reduction while maintaining nodule detection: Comparison of silver and copper X-ray spectrum modulation filters for chest CT using a phantom study with different reconstruction methods. Eur J Radiol 2023; 166:110969. [PMID: 37454556 DOI: 10.1016/j.ejrad.2023.110969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 07/03/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
PURPOSE To compare the capability of CTs obtained with a silver or copper x-ray beam spectral modulation filter (Ag filter and Cu filter) and reconstructed with FBP, hybrid-type IR and deep learning reconstruction (DLR) for radiation dose reduction for lung nodule detection using a chest phantom study. MATERIALS AND METHODS A chest CT phantom was scanned with a 320-detector row CT with Ag filter at 0.6, 1.6 and 2.5 mGy and Cu filters at 0.6, 1.6, 2.5 and 9.6 mGy, and reconstructed with the aforementioned methods. To compare image quality of all the CT data, SNRs and CNRs for any nodule were calculated for all protocols. To compare nodule detection capability among all protocols, the probability of detection of any nodule was assessed with a 5-point visual scoring system. Then, ROC analyses were performed to compare nodule detection capability of Ag and Cu filters for each radiation dose data with the same method and of the three methods for any radiation dose data and obtained with either filter. RESULTS At any of the doses, SNR, CNR and area under the curve for the Ag filter were significantly higher or larger than those for the Cu filter (p < 0.05). Moreover, with DLR, those values were significantly higher or larger than all the others for CTs obtained with any of the radiation doses and either filter (p < 0.05). CONCLUSION The Ag filter and DLR can significantly improve image quality and nodule detection capability compared with the Cu filter and other reconstruction methods at each of radiation doses used.
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Affiliation(s)
- Yuka Oshima
- Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Yoshiharu Ohno
- Department of Diagnostic Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan; Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
| | - Daisuke Takenaka
- Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan; Department of Diagnostic Radiology, Hyogo Cancer Center, Akashi, Hyogo, Japan
| | - Yuya Ito
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Hirona Kimata
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Kenji Fujii
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Naruomi Akino
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Nayu Hamabuchi
- Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Takahiro Matsuyama
- Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Hiroyuki Nagata
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Takahiro Ueda
- Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Hirotaka Ikeda
- Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Yoshiyuki Ozawa
- Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Takeshi Yoshikawa
- Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan; Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Hiroshi Toyama
- Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
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Zhou W, Malave MN, Maloney JA, White C, Weinman JP, Huo D, Neuberger I. Radiation dose reduction using spectral shaping in pediatric non-contrast sinus CT. Pediatr Radiol 2023; 53:2069-2078. [PMID: 37341726 DOI: 10.1007/s00247-023-05699-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/22/2023]
Abstract
BACKGROUND CT is the standard imaging technique to evaluate pediatric sinuses. Given the potential risks of radiation exposure in children, it is important to reduce pediatric CT dose and maintain image quality. OBJECTIVE To study the utility of spectral shaping with tin filtration to improve dose efficiency for pediatric sinus CT exams. MATERIALS AND METHODS A head phantom was scanned on a commercial dual-source CT using a conventional protocol (120 kV) and a proposed 100 kV with a 0.4-mm tin filter (Sn100 kV) protocol for comparison. Entrance point dose (EPD) of eye and parotid gland region was measured by an ion chamber. Sixty pediatric sinus CT exams (33 acquired with 120 kV, 27 acquired with Sn100 kV) were retrospectively collected. All patient images were objectively measured for image quality and blindly reviewed by 4 pediatric neuroradiologists for overall noise, overall diagnostic quality, and delineation of 4 critical paranasal sinus structures, using a 5-point Likert scale. RESULTS Phantom CTDIvol from Sn100 kV is 4.35 mGy, compared to CTDIvol of 5.73 mGy from 120 kV at an identical noise level. EPD of sensitive organs decreases in Sn100 kV (e.g., right eye EPD 3.83±0.42 mGy), compared to 120 kV (5.26±0.24 mGy). Patients in the 2 protocol groups were age and weight (unpaired T test P>0.05) matched. The patient CTDIvol of Sn100 kV (4.45±0.47 mGy) is significantly lower than 120 kV (5.56±0.48 mGy, unpaired T test P<0.001). No statistically significant difference for any subjective readers' score (Wilcoxon test P>0.05) was found between the two groups, indicating proposed spectral shaping provides equivalent diagnostic image quality. CONCLUSION Phantom and patient results demonstrate that spectral shaping can significantly reduce radiation dose for non-contrast pediatric sinus CT without compromising diagnostic quality.
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Affiliation(s)
- Wei Zhou
- Radiology, University of Colorado, Anschutz Medical Campus, 13001 E 17Th Pl, Aurora, CO, USA
| | - Maricarmen Nazario Malave
- Radiology, University of Colorado, Anschutz Medical Campus, 13001 E 17Th Pl, Aurora, CO, USA
- Radiology, Children's Hospital Colorado, 13123 E 16Th Ave, Aurora, CO, USA
| | - John A Maloney
- Radiology, University of Colorado, Anschutz Medical Campus, 13001 E 17Th Pl, Aurora, CO, USA
- Radiology, Children's Hospital Colorado, 13123 E 16Th Ave, Aurora, CO, USA
| | - Christina White
- Radiology, University of Colorado, Anschutz Medical Campus, 13001 E 17Th Pl, Aurora, CO, USA
- Radiology, Children's Hospital Colorado, 13123 E 16Th Ave, Aurora, CO, USA
| | - Jason P Weinman
- Radiology, University of Colorado, Anschutz Medical Campus, 13001 E 17Th Pl, Aurora, CO, USA
- Radiology, Children's Hospital Colorado, 13123 E 16Th Ave, Aurora, CO, USA
| | - Donglai Huo
- Radiology, University of Colorado, Anschutz Medical Campus, 13001 E 17Th Pl, Aurora, CO, USA
| | - Ilana Neuberger
- Radiology, University of Colorado, Anschutz Medical Campus, 13001 E 17Th Pl, Aurora, CO, USA.
- Radiology, Children's Hospital Colorado, 13123 E 16Th Ave, Aurora, CO, USA.
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Kunz AS, Grunz JP, Halt D, Kalogirou C, Luetkens KS, Patzer TS, Christner SA, Sauer ST, Bley TA, Huflage H. Tin-filtered 100 kV Ultra-low-dose Abdominal CT for Calculi Detection in the Urinary Tract: A Comparative Study of 510 Cases. Acad Radiol 2022:S1076-6332(22)00409-3. [PMID: 35963837 DOI: 10.1016/j.acra.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/14/2022] [Accepted: 07/14/2022] [Indexed: 11/23/2022]
Abstract
OBJECTIVES For detection of urinary calculi, unenhanced low-dose computed tomography is the method of choice, outperforming radiography and ultrasound. This retrospective monocentric study aims to compare a clinically established, dedicated low-dose imaging protocol for detection of urinary calculi with an ultra-low-dose protocol employing tin prefiltration at a standardized tube voltage of 100 kVp. METHODS Two study arms included a total of 510 cases. The "low-dose group" was comprised of 290 individuals (96 women; age 49 ± 16 years; BMI 27.23 ± 5.60 kg/m2). The "ultra-low-dose group" with Sn100 kVp consisted of 220 patients (84 women; age 47 ± 17 years; BMI 26.82 ± 5.62 kg/m2). No significant difference was ascertained for comparison of age (p = 0.132) and BMI (p = 0.207) between cohorts. For quantitative assessment of image quality, image noise was assessed. RESULTS No significant difference regarding frequency of calculi detection was found between groups (p = 0.596). Compared to the low-dose protocol (3.08 mSv; IQR 2.22-4.02 mSv), effective dose was reduced by 62.35% with the ultra-low-dose protocol employing spectral shaping (1.16 mSv; IQR 0.89-1.54 mSv). Image noise was calculated at 18.90 (IQR 17.39-21.20) for the low-dose protocol and at 18.69 (IQR 17.30-21.62) for the ultra-low-dose spectral shaping protocol. No significant difference was ascertained for comparison between groups (p = 0.793). CONCLUSION For urinary calculi detection, ultra-low-dose scans utilizing spectral shaping by means of tin prefiltration at 100 kVp allow for considerable dose reduction of up to 62% over conventional low-dose CT without compromising image quality.
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Huflage H, Grunz JP, Hackenbroch C, Halt D, Luetkens KS, Alfred Schmidt AM, Patzer TS, Ergün S, Bley TA, Kunz AS. Metal artefact reduction in low-dose computed tomography: Benefits of tin prefiltration versus postprocessing of dual-energy datasets over conventional CT imaging. Radiography (Lond) 2022; 28:690-696. [PMID: 35728278 DOI: 10.1016/j.radi.2022.05.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/01/2022] [Accepted: 05/30/2022] [Indexed: 11/26/2022]
Abstract
INTRODUCTION The purpose of this study was to determine the potential for metal artefact reduction in low-dose multidetector CT as these pose a frequent challenge in clinical routine. Investigations focused on whether spectral shaping via tin prefiltration, virtual monoenergetic imaging or virtual blend imaging (VBI) offers superior image quality in comparison with conventional CT imaging. METHODS Using a third-generation dual-source CT scanner, two cadaveric specimens with different metal implants (dental, cervical spine, hip, knee) were examined with acquisition protocols matched for radiation dose with regards to tube voltage and current. In order to allow for precise comparison, and due to the relatively short scan lengths, automatic tube current modulation was disabled. Specifically, the following scan protocals were examined: conventional CT protocols (100/120 kVp), tin prefiltration (Sn 100/Sn 150 kVp), VBI and virtual monoenergetic imaging (VME 100/120/150 keV). Mean attenuation and image noise were measured in hyperdense and hypodense artefacts, in artefact-impaired and artefact-free soft tissue. Subjective image quality was rated independently by three radiologists. RESULTS Objectively, Sn 150 kVp allowed for the best reduction of hyperdense streak artefacts (p < 0.001), while VME 150 keV and Sn 150 kVp protocols facilitated equally good reduction of hypodense artefacts (p = 0.173). Artefact-impaired soft tissue attenuation was lowest in Sn 150 kVp protocols (p ≤ 0.011), whereas all VME showed significantly less image noise compared to conventional or tin-filtered protocols (p ≤ 0.001). Subjective assessment favoured Sn 150 kVp regarding hyperdense streak artefacts and delineation of cortical bone (p ≤ 0.005). The intraclass correlation coefficient was 0.776 (95% confidence interval: 0.712-0.831; p < 0.001) indicating good interrater reliability. CONCLUSION In the presence of metal implants in our cadaveric study, tin prefiltration with 150 kVp offers superior artefact reduction for low-dose CT imaging of osseous tissue compared with virtual monoenergetic images of dual-energy datasets. The delineation of cortical boundaries seems to benefit particularly from spectral shaping. IMPLICATIONS FOR PRACTICE Low-dose CT imaging of osseous tissue in combination with tin prefiltration allows for superior metal artefact reduction when compared to virtual monoenergetic images of dual-energy datasets. Employing this technique ought to be considered in daily routine when metal implants are present within the scan volume as findings suggest it allows for radiation dose reduction and facilitates diagnosis relevant to further treatment.
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Affiliation(s)
- H Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
| | - J-P Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
| | - C Hackenbroch
- Department of Diagnostic and Interventional Radiology and Neuroradiology, German Armed Forces Hospital Ulm, Oberer Eselsberg 40, 89081 Ulm, Germany; Department of Diagnostic and Interventional Radiology, University Hospital Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - D Halt
- Department of Diagnostic and Interventional Radiology and Neuroradiology, German Armed Forces Hospital Ulm, Oberer Eselsberg 40, 89081 Ulm, Germany.
| | - K S Luetkens
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
| | - A M Alfred Schmidt
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
| | - T S Patzer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
| | - S Ergün
- Institute of Anatomy and Cell Biology, University of Würzburg, Koellikerstraße 6, 97070 Würzburg, Germany.
| | - T A Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
| | - A S Kunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
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Agostini A, Borgheresi A, Carotti M, Ottaviani L, Badaloni M, Floridi C, Giovagnoni A. Third-generation iterative reconstruction on a dual-source, high-pitch, low-dose chest CT protocol with tin filter for spectral shaping at 100 kV: a study on a small series of COVID-19 patients. Radiol Med 2020; 126:388-398. [PMID: 33044732 PMCID: PMC7548313 DOI: 10.1007/s11547-020-01298-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/23/2020] [Indexed: 12/11/2022]
Abstract
Objectives To investigate the role of third-generation iterative reconstruction (ADMIRE) in dual-source, high-pitch chest CT protocol with spectral shaping at 100 kVp in Coronavirus disease 2019 (COVID-19). Methods Confirmed COVID-19 inpatients undergoing to unenhanced chest CT were scanned with a dual-energy acquisition (DECT, 90/150Sn kV) and a dual-source, high-pitch acquisition with tin-filtered 100 kVp (LDCT). On the DECT with ADMIRE 3 (DECT3) were evaluated the pulmonary findings and their extension (25-point score). Two radiologists in consensus evaluated with 5-point scales the overall image quality, the anatomical structures, and the elementary findings on LDCT reconstructed with filtered backprojection (LDCT0), with ADMIRE 3 (LDCT3) and 5 (LDCT5), and on DECT3. The signal-to-noise ratio (SNR), the body mass index, the exposure times, and the radiation doses were recorded. Results Seventy-five patients (57 M/18F; median age: 63 y.o.) were included, with median pulmonary extension of 13/25 points. The imaging findings were detected in proportion comparable to the available literature. The ADMIRE significantly improved the SNR in LDCT (p < 0.00001) with almost no significant differences in overweight patients. The LDCT had median effective dose of 0.39 mSv and acquisition time of 0.71 s with significantly less motion artifacts than DECT (p < 0.00001). The DECT3 and LDCT3 provided the best image quality and depiction of pulmonary anatomy and imaging findings, with significant differences among all the series (p < 0.00001). Conclusion The LDCT with spectral shaping and ADMIRE3 provided acceptable image quality in the evaluation of patients with COVID-19, with significantly reduced radiation dose and motion artifacts.
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Affiliation(s)
- Andrea Agostini
- Department of Clinical, Special and Dental Sciences, University Politecnica delle Marche, Ancona, Italy.,Department of Radiology, Division of Special and Pediatric Radiology, University Hospital "Umberto I - Lancisi - Salesi", Via Conca 71, 60126, Ancona, AN, Italy
| | - Alessandra Borgheresi
- Department of Radiology, Division of Special and Pediatric Radiology, University Hospital "Umberto I - Lancisi - Salesi", Via Conca 71, 60126, Ancona, AN, Italy.
| | - Marina Carotti
- Department of Clinical, Special and Dental Sciences, University Politecnica delle Marche, Ancona, Italy.,Department of Radiology, Division of Special and Pediatric Radiology, University Hospital "Umberto I - Lancisi - Salesi", Via Conca 71, 60126, Ancona, AN, Italy
| | - Letizia Ottaviani
- Department of Radiology, Division of Special and Pediatric Radiology, University Hospital "Umberto I - Lancisi - Salesi", Via Conca 71, 60126, Ancona, AN, Italy
| | - Myriam Badaloni
- Department of Radiology, Division of Special and Pediatric Radiology, University Hospital "Umberto I - Lancisi - Salesi", Via Conca 71, 60126, Ancona, AN, Italy
| | - Chiara Floridi
- Department of Clinical, Special and Dental Sciences, University Politecnica delle Marche, Ancona, Italy.,Department of Radiology, Division of Special and Pediatric Radiology, University Hospital "Umberto I - Lancisi - Salesi", Via Conca 71, 60126, Ancona, AN, Italy
| | - Andrea Giovagnoni
- Department of Clinical, Special and Dental Sciences, University Politecnica delle Marche, Ancona, Italy.,Department of Radiology, Division of Special and Pediatric Radiology, University Hospital "Umberto I - Lancisi - Salesi", Via Conca 71, 60126, Ancona, AN, Italy
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Agostini A, Floridi C, Borgheresi A, Badaloni M, Esposto Pirani P, Terilli F, Ottaviani L, Giovagnoni A. Proposal of a low-dose, long-pitch, dual-source chest CT protocol on third-generation dual-source CT using a tin filter for spectral shaping at 100 kVp for CoronaVirus Disease 2019 (COVID-19) patients: a feasibility study. Radiol Med 2020; 125:365-73. [PMID: 32239472 DOI: 10.1007/s11547-020-01179-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 03/18/2020] [Indexed: 02/06/2023]
Abstract
Aim To subjectively and objectively evaluate the feasibility and diagnostic reliability of a low-dose, long-pitch dual-source chest CT protocol on third-generation dual-source CT (DSCT) with spectral shaping at 100Sn kVp for COVID-19 patients. Materials and methods Patients with COVID-19 and positive swab-test undergoing to a chest CT on third-generation DSCT were included. The imaging protocol included a dual-energy acquisition (HD-DECT, 90/150Sn kVp) and fast, low-dose, long-pitch CT, dual-source scan at 100Sn kVp (LDCT). Subjective (Likert Scales) and objective (signal-to-noise and contrast-to-noise ratios, SNR and CNR) analyses were performed; radiation dose and acquisition times were recorded. Nonparametric tests were used. Results The median radiation dose was lower for LDCT than HD-DECT (Effective dose, ED: 0.28 mSv vs. 3.28 mSv, p = 0.016). LDCT had median acquisition time of 0.62 s (vs 2.02 s, p = 0.016). SNR and CNR were significantly different in several thoracic structures between HD-DECT and LDCT, with exception of lung parenchyma. Qualitative analysis demonstrated significant reduction in motion artifacts (p = 0.031) with comparable diagnostic reliability between HD-DECT and LDCT. Conclusions Ultra-low-dose, dual-source, fast CT protocol provides highly diagnostic images for COVID-19 with potential for reduction in dose and motion artifacts.
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Li J, Mai Z, Zhang Z, Cui J, Yang M, Ma X, Wang Y. Chest CT screening in patients with overweight or obesity using spectral shaping at 150 kVp: compared with 120 kVp protocol and spectral shaping at 100 kVp protocol. Jpn J Radiol 2020; 38:451-457. [PMID: 32048134 DOI: 10.1007/s11604-020-00925-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 01/29/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE To evaluate the image quality (IQ) and the figure of merit (FoM) of chest CT screening in patients with overweight or obesity using a tin filter for spectral shaping at 150 kVp. MATERIALS AND METHODS Patients with overweight or obesity (N = 150, body mass index ≥ 26 kg/m2) with indications for chest CT screening were prospectively enrolled and randomly divided into three groups: 120 kVp group (standard radiation dose/tube voltage, 120 kVp/CT volume does index, 4.68 mGy); Sn100 kVp group (1/10th radiation dose level/100 kVp with a tin filter/0.47 mGy); Sn150 kVp group (1/2th radiation dose level/150 kVp with a tin filter/2.34 mGy). IQ and FoMs were evaluated and compared among the three groups. RESULTS Image noise, signal-to-noise ratios and subjective IQ scores were significantly higher in the Sn150 kVp group than those in the Sn100 kVp group (all p < 0.05), but were not significantly different with those in the 120 kVp group. FoMs in the Sn150 kVp group were significantly higher than those in the 120 kVp group (all p < 0.05), but showed no statistical difference with those in the Sn100 kVp group. CONCLUSIONS Compared with scanning at 120 kVp, chest CT screening performed at 150 kVp with spectral shaping substantially reduces the radiation dose in overweight and obese patients while maintaining IQ.
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Affiliation(s)
- Jianwen Li
- Department of Radiology, The Second People's Hospital of Shizuishan, NO.246 West Youyi Street, Shizuishan, 753000, Ningxia, China
| | - Zhifeng Mai
- Department of Radiology, The Second People's Hospital of Shizuishan, NO.246 West Youyi Street, Shizuishan, 753000, Ningxia, China
| | - Zhihong Zhang
- Department of Pharmacy, The First People's Hospital of Shizuishan, NO.1 Kangle Road, Shizuishan, 753000, Ningxia, China
| | - Jiamang Cui
- Department of Radiology, The Second People's Hospital of Shizuishan, NO.246 West Youyi Street, Shizuishan, 753000, Ningxia, China
| | - Mingjie Yang
- Department of Radiology, The Second People's Hospital of Shizuishan, NO.246 West Youyi Street, Shizuishan, 753000, Ningxia, China
| | - Xia Ma
- Department of Radiology, The Second People's Hospital of Shizuishan, NO.246 West Youyi Street, Shizuishan, 753000, Ningxia, China
| | - Yan Wang
- Department of Radiology, The Second People's Hospital of Shizuishan, NO.246 West Youyi Street, Shizuishan, 753000, Ningxia, China.
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Vivier S, Deken V, Arous Y, Faivre JB, Duhamel A, Deschildre A, Flohr T, Remy J, Remy-Jardin M. Pediatric chest computed tomography at 100 kVp with tin filtration: comparison of image quality with 70-kVp imaging at comparable radiation dose. Pediatr Radiol 2020; 50:188-98. [PMID: 31853569 DOI: 10.1007/s00247-019-04543-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 07/16/2019] [Accepted: 09/20/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND Radiation dose reduction is a primary objective in pediatric populations owing to the well-known risks of radiation-induced cancers. Low-energy photons participate in the radiation dose without significantly contributing to image formation. Their suppression by means of tin filtration should decrease the image noise, anticipating a subsequent application to dose saving. OBJECTIVE To investigate the level of noise reduction achievable with tin (Sn) filtration at 100 kVp for chest computed tomography (CT) in comparison with a standard scanning mode at 70 kVp with comparable radiation dose. MATERIALS AND METHODS Fifty consecutive children (Group 1) underwent non-contrast chest CT examinations on a third-generation dual-source CT system at tin-filtered 100 kVp and pitch 2. The tube-current time product (mAs) was adjusted to maintain the predicted dose length product (DLP) value at 70 kVp for the respective patient. Each child was then paired by weight and age to a child scanned at 70 kVp on the same CT unit (Group 2); Group 2 patients were consecutive patients, retrospectively selected from our database of children prospectively scanned at 70 kVp. Objective and subjective image quality were compared between the two groups of patients to investigate the overall image quality and level of noise reduction that could be subsequently achievable with tin filtration in clinical practice. RESULTS The mean image noise was significantly lower in Group 1 compared to Group 2 when measured in the air (P<0.0001) and inside the aorta (P<0.001). The mean noise reduction was 21.6% (standard deviation [SD] 16.1) around the thorax and 12.0% (SD 32.7) inside the thorax. There was no significant difference in subjective image quality of lung and mediastinal images with excellent overall subjective scores in both groups. CONCLUSION At comparable radiation dose, the image noise was found to be reduced by 21.6% compared to the 70-kVp protocol, providing basis for dose reduction without altering image quality in further investigations.
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Wetzl M, May MS, Weinmann D, Hammon M, Treutlein C, Zeilinger M, Kiefer A, Trollmann R, Woelfle J, Uder M, Rompel O. Dual-source computed tomography of the lung with spectral shaping and advanced iterative reconstruction: potential for maximum radiation dose reduction. Pediatr Radiol 2020; 50:1240-1248. [PMID: 32556576 PMCID: PMC7398955 DOI: 10.1007/s00247-020-04714-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 03/06/2020] [Accepted: 05/12/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND Radiation dose at CT should be as low as possible without compromising diagnostic quality. OBJECTIVE To assess the potential for maximum dose reduction of pediatric lung dual-source CT with spectral shaping and advanced iterative reconstruction (ADMIRE). MATERIALS AND METHODS We retrospectively analyzed dual-source CT acquisitions in a full-dose group (FD: 100 kV, 64 reference mAs) and in three groups with spectral shaping and differing reference mAs values (Sn: 100 kV, 96/64/32 reference mAs), each group consisting of 16 patients (age mean 11.5 years, standard deviation 4.8 years, median 12.8 years, range 1.3-18 years). Advanced iterative reconstruction of images was performed with different strengths (FD: ADMIRE Level 2; Sn: ADMIRE Levels 2, 3 and 4). We analyzed dose parameters and measured noise. Diagnostic confidence and detectability of lung lesions as well as anatomical structures were assessed using a Likert scale (from 1 [unacceptable] to 4 [fully acceptable]). RESULTS Compared to full dose, effective dose was reduced to 16.7% in the Sn 96 group, 11.1% in Sn64, and 5.5% in Sn32 (P<0.001). Noise values of Sn64ADM4 did not statistically differ from those in FDADM2 (45.7 vs. 38.9 Hounsfield units [HU]; P=0.132), whereas noise was significantly higher in Sn32ADM4 compared to Sn64ADM4 (61.5 HU; P<0.001). A Likert score >3 was reached in Sn64ADM4 regarding diagnostic confidence (3.2) and detectability of lung lesions (3.3). For detectability of most anatomical structures, no significant differences were found between FDAM2 and Sn64ADM4 (P≥0.05). CONCLUSION In pediatric lung dual-source CT, spectral shaping together with ADMIRE 4 enable radiation dose reduction to about 10% of a full-dose protocol while maintaining an acceptable diagnostic quality.
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Affiliation(s)
- Matthias Wetzl
- Department of Radiology, University Hospital Erlangen, Erlangen, Germany.
| | - Matthias S. May
- grid.411668.c0000 0000 9935 6525Department of Radiology, University Hospital Erlangen, Erlangen, Germany ,grid.411668.c0000 0000 9935 6525Imaging Science Institute, University Hospital Erlangen, Erlangen, Germany
| | - Daniel Weinmann
- grid.411668.c0000 0000 9935 6525Department of Radiology, University Hospital Erlangen, Erlangen, Germany
| | - Matthias Hammon
- grid.411668.c0000 0000 9935 6525Department of Radiology, University Hospital Erlangen, Erlangen, Germany
| | - Christoph Treutlein
- grid.411668.c0000 0000 9935 6525Department of Radiology, University Hospital Erlangen, Erlangen, Germany
| | - Martin Zeilinger
- grid.411668.c0000 0000 9935 6525Department of Radiology, University Hospital Erlangen, Erlangen, Germany
| | - Alexander Kiefer
- grid.411668.c0000 0000 9935 6525Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, Erlangen, Germany
| | - Regina Trollmann
- grid.411668.c0000 0000 9935 6525Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, Erlangen, Germany
| | - Joachim Woelfle
- grid.411668.c0000 0000 9935 6525Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, Erlangen, Germany
| | - Michael Uder
- grid.411668.c0000 0000 9935 6525Department of Radiology, University Hospital Erlangen, Erlangen, Germany ,grid.411668.c0000 0000 9935 6525Imaging Science Institute, University Hospital Erlangen, Erlangen, Germany
| | - Oliver Rompel
- grid.411668.c0000 0000 9935 6525Department of Radiology, University Hospital Erlangen, Erlangen, Germany
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Kim CR, Jeon JY. Radiation dose and image conspicuity comparison between conventional 120 kVp and 150 kVp with spectral beam shaping for temporal bone CT. Eur J Radiol 2018; 102:68-73. [PMID: 29685547 DOI: 10.1016/j.ejrad.2018.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/09/2018] [Accepted: 03/03/2018] [Indexed: 11/15/2022]
Abstract
OBJECTIVE The purpose of this article is to compare radiation doses and conspicuity of anatomic landmarks of the temporal bone between the CT technique using spectral beam shaping at 150 kVp with a dedicated tin filter (150 kVp-Sn) and the conventional protocol at 120 kVp. METHODS 25 patients (mean age, 46.8 ± 21.2 years) were examined using the 150-kVp Sn protocol (200 reference mAs using automated tube current modulation, 64 × 0.6 mm collimation, 0.6 mm slice thickness, pitch 0.8), whereas 30 patients (mean age, 54.5 ± 17.8 years) underwent the 120-kVp protocol (180 mAs, 128 × 0.6 mm collimation, 0.6 mm slice thickness, pitch 0.8). Radiation doses were compared between the two acquisition techniques, and dosimetric data from the literature were reviewed for comparison of radiation dose reduction. Subjective conspicuity of 23 anatomic landmarks of the temporal bone, expressed by 5-point rating scale and objective conspicuity by signal-to-noise ratio (SNR) which measured in 4 different regions of interest (ROI), were compared between 150-kVp Sn and 120-kVp acquisitions. RESULTS The mean dose-length-product (DLP) and effective dose were significantly lower for the 150-kVp Sn scans (0.26 ± 0.26 mSv) compared with the 120-kVp scans (0.92 ± 0.10 mSv, p < 0.001). The lowest effective dose from the literature-based protocols was 0.31 ± 0.12 mSv, which proposed as a low-dose protocol in the setting of spiral multislice temporal bone CT. SNR was slightly superior for 120-kVp images, however analyzability of the 23 anatomic structures did not differ significantly between 150-kVp Sn and 120-kVp scans. CONCLUSION Temporal bone CT performed at 150 kVp with an additional tin filter for spectral shaping markedly reduced radiation exposure when compared with conventional temporal bone CT at 120 kVp while maintaining anatomic conspicuity. The decreased radiation dose of the 150-kVp Sn was also lower in comparison to the previous literature-based low-dose temporal bone CT protocol.
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Affiliation(s)
- Chang Rae Kim
- Department of Radiology, Gachon University, Gil Medical Center, 21, Namdong-daero 774 beon-gil, Namdong-gu, Incheon, 21565, Republic of Korea.
| | - Ji Young Jeon
- Department of Radiology, Gachon University, Gil Medical Center, 21, Namdong-daero 774 beon-gil, Namdong-gu, Incheon, 21565, Republic of Korea.
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Bodelle B, Fischbach C, Booz C, Yel I, Frellesen C, Kaup M, Beeres M, Vogl TJ, Scholtz JE. Single-energy pediatric chest computed tomography with spectral filtration at 100 kVp: effects on radiation parameters and image quality. Pediatr Radiol 2017; 47:831-837. [PMID: 28352977 DOI: 10.1007/s00247-017-3813-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/22/2016] [Accepted: 02/15/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND Most of the applied radiation dose at CT is in the lower photon energy range, which is of limited diagnostic importance. OBJECTIVE To investigate image quality and effects on radiation parameters of 100-kVp spectral filtration single-energy chest CT using a tin-filter at third-generation dual-source CT in comparison to standard 100-kVp chest CT. MATERIALS AND METHODS Thirty-three children referred for a non-contrast chest CT performed on a third-generation dual-source CT scanner were examined at 100 kVp with a dedicated tin filter with a tube current-time product resulting in standard protocol dose. We compared resulting images with images from children examined using standard single-source chest CT at 100 kVp. We assessed objective and subjective image quality and compared radiation dose parameters. RESULTS Radiation dose was comparable for children 5 years old and younger, and it was moderately decreased for older children when using spectral filtration (P=0.006). Effective tube current increased significantly (P=0.0001) with spectral filtration, up to a factor of 10. Signal-to-noise ratio and image noise were similar for both examination techniques (P≥0.06). Subjective image quality showed no significant differences (P≥0.2). CONCLUSION Using 100-kVp spectral filtration chest CT in children by means of a tube-based tin-filter on a third-generation dual-source CT scanner increases effective tube current up to a factor of 10 to provide similar image quality at equivalent dose compared to standard single-source CT without spectral filtration.
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Affiliation(s)
- Boris Bodelle
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany.
| | - Constanze Fischbach
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Christian Booz
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Ibrahim Yel
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Claudia Frellesen
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Moritz Kaup
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Martin Beeres
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Thomas J Vogl
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Jan-Erik Scholtz
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
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May MS, Brand M, Lell MM, Sedlmair M, Allmendinger T, Uder M, Wuest W. Radiation dose reduction in parasinus CT by spectral shaping. Neuroradiology 2017; 59:169-176. [PMID: 28091696 DOI: 10.1007/s00234-016-1780-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 12/25/2016] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Spectral shaping aims to narrow the X-ray spectrum of clinical CT. The aim of this study was to determine the image quality and the extent of radiation dose reduction that can be achieved by tin prefiltration for parasinus CT. METHODS All scans were performed with a third generation dual-source CT scanner. A study protocol was designed using 100 kV tube voltage with tin prefiltration (200 mAs) that provides image noise levels comparable to a low-dose reference protocol using 100 kV without spectral shaping (25 mAs). One hundred consecutive patients were prospectively enrolled and randomly assigned to the study or control group. All patients signed written informed consent. The study protocol was approved by the local Institutional Review Board and applies to the HIPAA. Subjective and objective image quality (attenuation values, image noise, and contrast-to-noise ratio (CNR)) were assessed. Radiation exposure was assessed as volumetric CT dose index, and effective dose was estimated. Mann-Whitney U test was performed for radiation exposure and for image noise comparison. RESULTS All scans were of diagnostic image quality. Image noise in air, in the retrobulbar fat, and in the eye globe was comparable between both groups (all p > 0.05). CNReye globe/air did not differ significantly between both groups (p = 0.7). Radiation exposure (1.7 vs. 2.1 mGy, p < 0.01) and effective dose (0.055 vs. 0.066 mSv, p < 0.01) were significantly reduced in the study group. CONCLUSION Radiation dose can be further reduced by 17% for low-dose parasinus CT by tin prefiltration maintaining diagnostic image quality.
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Affiliation(s)
- Matthias S May
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054, Erlangen, Germany
| | - Michael Brand
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054, Erlangen, Germany
| | - Michael M Lell
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054, Erlangen, Germany
| | | | | | - Michael Uder
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054, Erlangen, Germany
| | - Wolfgang Wuest
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054, Erlangen, Germany.
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Dewes P, Frellesen C, Scholtz JE, Fischer S, Vogl TJ, Bauer RW, Schulz B. Low-dose abdominal computed tomography for detection of urinary stone disease - Impact of additional spectral shaping of the X-ray beam on image quality and dose parameters. Eur J Radiol 2016; 85:1058-62. [PMID: 27161052 DOI: 10.1016/j.ejrad.2016.03.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/10/2016] [Accepted: 03/16/2016] [Indexed: 11/19/2022]
Abstract
OBJECTIVES To evaluate a novel tin filter-based abdominal CT protocol for urolithiasis in terms of image quality and CT dose parameters. METHODS 130 consecutive patients with suspected urolithiasis underwent non-enhanced CT with three different protocols: 48 patients (group 1) were examined at tin-filtered 150kV (150kV Sn) on a third-generation dual-source-CT, 33 patients were examined with automated kV-selection (110-140kV) based on the scout view on the same CT-device (group 2), and 49 patients were examined on a second-generation dual-source-CT (group 3) with automated kV-selection (100-140kV). Automated exposure control was active in all groups. Image quality was subjectively evaluated on a 5-point-likert-scale by two radiologists and interobserver agreement as well as signal-to-noise-ratio (SNR) was calculated. Dose-length-product (DLP) and volume CT dose index (CTDIvol) were compared. RESULTS Image quality was rated in favour for the tin filter protocol with excellent interobserver agreement (ICC=0.86-0.91) and the difference reached statistical significance (p<0.001). SNR was significantly higher in group 1 and 2 compared to second-generation DSCT (p<0.001). On third-generation dual-source CT, there was no significant difference in SNR between the 150kV Sn and the automated kV selection protocol (p=0.5). The DLP of group 1 was 23% and 21% (p<0.002) lower in comparison to group 2 and 3, respectively. So was the CTDIvol of group 1 compared to group 2 (-36%) and 3 (-32%) (p<0.001). CONCLUSION Additional shaping of a 150kV source spectrum by a tin filter substantially lowers patient exposure while improving image quality on un-enhanced abdominal computed tomography for urinary stone disease.
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Affiliation(s)
- Patricia Dewes
- University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt, Germany
| | - Claudia Frellesen
- University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt, Germany
| | - Jan-Erik Scholtz
- University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt, Germany
| | - Sebastian Fischer
- University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt, Germany
| | - Thomas J Vogl
- University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt, Germany
| | - Ralf W Bauer
- University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt, Germany.
| | - Boris Schulz
- University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt, Germany
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Wuest W, May M, Saake M, Brand M, Uder M, Lell M. Low-Dose CT of the Paranasal Sinuses: Minimizing X-Ray Exposure with Spectral Shaping. Eur Radiol 2016; 26:4155-4161. [PMID: 26911887 DOI: 10.1007/s00330-016-4263-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 01/28/2016] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Shaping the energy spectrum of the X-ray beam has been shown to be beneficial in low-dose CT. This study's aim was to investigate dose and image quality of tin filtration at 100 kV for pre-operative planning in low-dose paranasal CT imaging in a large patient cohort. METHODS In a prospective trial, 129 patients were included. 64 patients were randomly assigned to the study protocol (100 kV with additional tin filtration, 150mAs, 192x0.6-mm slice collimation) and 65 patients to the standard low-dose protocol (100 kV, 50mAs, 128 × 0.6-mm slice collimation). To assess the image quality, subjective parameters were evaluated using a five-point scale. This scale was applied on overall image quality and contour delineation of critical anatomical structures. RESULTS All scans were of diagnostic image quality. Bony structures were of good diagnostic image quality in both groups, soft tissues were of sufficient diagnostic image quality in the study group because of a high level of noise. Radiation exposure was very low in both groups, but significantly lower in the study group (CTDIvol 1.2 mGy vs. 4.4 mGy, p < 0.001). CONCLUSIONS Spectral optimization (tin filtration at 100 kV) allows for visualization of the paranasal sinus with sufficient image quality at a very low radiation exposure. KEY POINTS • Spectral optimization (tin filtration) is beneficial to low-dose parasinus CT • Tin filtration at 100 kV yields sufficient image quality for pre-operative planning • Diagnostic parasinus CT can be performed with an effective dose <0.05 mSv.
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Affiliation(s)
- Wolfgang Wuest
- Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany. .,Radiological Institute, Maximiliansplatz 1, 91054, Erlangen, Germany.
| | - Matthias May
- Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Marc Saake
- Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Michael Brand
- Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Michael Uder
- Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Michael Lell
- Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
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Haubenreisser H, Meyer M, Sudarski S, Allmendinger T, Schoenberg SO, Henzler T. Unenhanced third-generation dual-source chest CT using a tin filter for spectral shaping at 100kVp. Eur J Radiol 2015; 84:1608-1613. [PMID: 26001437 DOI: 10.1016/j.ejrad.2015.04.018] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 04/20/2015] [Accepted: 04/21/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To prospectively investigate image quality and radiation dose of 100kVp spectral shaping chest CT using a dedicated tin filter on a 3rd generation dual-source CT (DSCT) in comparison to standard 100kVp chest CT. METHODS Sixty patients referred for a non-contrast chest on a 3rd generation DSCT were prospectively included and examined at 100kVp with a dedicated tin filter. These patients were retrospectively matched with patients that were examined on a 2nd generation DSCT at 100kVp without tin filter. Objective and subjective image quality was assessed in various anatomic regions and radiation dose was compared. RESULTS Radiation dose was decreased by 90% using the tin filter (3.0 vs 0.32mSv). Soft tissue attenuation and image noise was not statistically different for both examination techniques (p>0.05), however image noise was found to be significantly higher in the trachea when using the additional tin filter (p=0.002). SNR was found to be statistically similar in pulmonary tissue, significantly lower when measured in air and significantly higher in the aorta for the scans on the 3rd generation DSCT. Subjective image quality with regard to overall quality and image noise and sharpness was not statistically significantly different (p>0.05). CONCLUSION 100kVp spectral shaping chest CT by means of a tube-based tin-filter on a 3rd generation DSCT allows 90% dose reduction when compared to 100kVp chest CT on a 2nd generation DSCT without spectral shaping.
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Affiliation(s)
- Holger Haubenreisser
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany.
| | - Mathias Meyer
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany
| | - Sonja Sudarski
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany
| | | | - Stefan O Schoenberg
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany
| | - Thomas Henzler
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany
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