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Viry A, Vitzthum V, Monnin P, Bize J, Rotzinger D, Racine D. Optimization of CT pulmonary angiography for pulmonary embolism using task-based image quality assessment and diagnostic reference levels: A multicentric study. Phys Med 2024; 121:103365. [PMID: 38663347 DOI: 10.1016/j.ejmp.2024.103365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/12/2024] [Accepted: 04/19/2024] [Indexed: 05/12/2024] Open
Abstract
PURPOSE To establish size-specific diagnostic reference levels (DRLs) for pulmonary embolism (PE) based on patient CT examinations performed on 74 CT devices. To assess task-based image quality (IQ) for each device and to investigate the variability of dose and IQ across different CTs. To propose a dose/IQ optimization. METHODS 1051 CT pulmonary angiography dose data were collected. DRLs were calculated as the 75th percentile of CT dose index (CTDI) for two patient categories based on the thoracic perimeters. IQ was assessed with two thoracic phantom sizes using local acquisition parameters and three other dose levels. The area under the ROC curve (AUC) of a 2 mm low perfused vessel was assessed with a non-prewhitening with eye-filter model observer. The optimal IQ-dose point was mathematically assessed from the relationship between IQ and dose. RESULTS The DRLs of CTDIvol were 6.4 mGy and 10 mGy for the two patient categories. 75th percentiles of phantom CTDIvol were 6.3 mGy and 10 mGy for the two phantom sizes with inter-quartile AUC values of 0.047 and 0.066, respectively. After the optimization, 75th percentiles of phantom CTDIvol decreased to 5.9 mGy and 7.55 mGy and the interquartile AUC values were reduced to 0.025 and 0.057 for the two phantom sizes. CONCLUSION DRLs for PE were proposed as a function of patient thoracic perimeters. This study highlights the variability in terms of dose and IQ. An optimization process can be started individually and lead to a harmonization of practice throughout multiple CT sites.
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Affiliation(s)
- Anaïs Viry
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland.
| | - Veronika Vitzthum
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
| | - Pascal Monnin
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
| | - Julie Bize
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
| | - David Rotzinger
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Damien Racine
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
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Mohammadbeigi A, Shouraki JK, Ebrahiminik H, Nouri M, Bagheri H, Moradi H, Azizi A, Fadaee N, Soltanzadeh T, Moghimi Y. Pathology-based radiation dose in computed tomography: investigation of the effect of lung lesions on water-equivalent diameter, CTDIVol and SSDE in COVID-19 patients. RADIATION PROTECTION DOSIMETRY 2023; 199:2356-2365. [PMID: 37694671 DOI: 10.1093/rpd/ncad245] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 09/12/2023]
Abstract
Lung lesions can increase the CT number and affect the water-equivalent diameter (Dw), Dw-based conversion factor (CFw), and Dw-based size-specific dose estimate (SSDEw). We evaluated the effect of COVID-19 lesions and total severity score (TSS) on radiation dose considering the effect of automatic tube current modulation (ATCM) and fixed tube current (FTC). A total of 186 chest CT scans were categorised into five TSS groups, including healthy, minimal, mild, moderate and severe. The effective diameter (Deff), Dw, CFw, Deff-based conversion factor (CFeff), volume computed tomography dose index (CTDIVol), pathological dose impact factor (PDIF) 1 and SSDEw were calculated. TSS was correlated with Dw (r = 0.29, p-value = 0.001), CTDIVol (ATCM) (r = 0.23, p = 0.001) and PDIF (r = - 0.51, p-value = 0.001). $\overline{{\mathrm{SSDE}}_{\mathrm{w}}}$ (FTC) was significantly different among all groups. $\overline{{\mathrm{SSDE}}_{\mathrm{w}}}$ (ATCM) was greater for moderate (13%) and mild (14%) groups. Increasing TSS increase the Dw and causes a decrease in CFw and $\overline{{\mathrm{SSDE}}_{\mathrm{w}}}$ (FTC), and can increase $\overline{{\mathrm{SSDE}}_{\mathrm{w}}}$ (ATCM) in some Dw ranges.
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Affiliation(s)
- Ahmad Mohammadbeigi
- Department of Radiology Sciences and Research Center, AJA University of Medical Sciences, Tehran 1411718541, Iran
| | - Jalal Kargar Shouraki
- Department of Radiology Sciences and Research Center, AJA University of Medical Sciences, Tehran 1411718541, Iran
| | - Hojat Ebrahiminik
- Department of Interventional Radiology and Radiation Sciences and Research Center, AJA University of Medical Sciences, Tehran 1411718541, Iran
| | - Majid Nouri
- Infectious Diseases and Tropical Medicine Research Center (IDTMRC), AJA University of Medical Sciences, Tehran 1411718541, Iran
| | - Hamed Bagheri
- Radiation Sciences Research Center, AJA University of Medical Sciences, Tehran 1411718541, Iran
| | - Hamid Moradi
- Department of Radiology Sciences and Research Center, AJA University of Medical Sciences, Tehran 1411718541, Iran
| | - Ahmad Azizi
- Department of Radiology, Omid Hospital, Iran University of Medical Sciences, Tehran 1476919451, Iran
| | - Narges Fadaee
- Department of Community and Family Medicine, School of Medicine, Iran University of Medical Sciences, Tehran 1449614535, Iran
| | - Taher Soltanzadeh
- Naval Healthcare Department, Golestan Hospital, AJA University of Medical Sciences, Tehran 1668619551, Iran
| | - Yousef Moghimi
- Department of Radiology Sciences and Research Center, AJA University of Medical Sciences, Tehran 1411718541, Iran
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Inoue Y, Itoh H, Nagahara K, Hata H, Mitsui K. Relationships of Radiation Dose Indices with Body Size Indices in Adult Body Computed Tomography. Tomography 2023; 9:1381-1392. [PMID: 37489478 PMCID: PMC10366833 DOI: 10.3390/tomography9040110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 07/08/2023] [Accepted: 07/12/2023] [Indexed: 07/26/2023] Open
Abstract
We investigated the relationships between radiation dose indices and body size indices in adult body computed tomography (CT). A total of 3200 CT scans of the thoracic, abdominal, abdominopelvic, or thoraco-abdominopelvic regions performed using one of four CT scanners were analyzed. Volume CT dose index (CTDIvol) and dose length product (DLP) were compared with various body size indices derived from CT images (water-equivalent diameter, WED; effective diameter, ED) and physical measurements (weight, weight/height, body mass index, and body surface area). CTDIvol showed excellent positive linear correlations with WED and ED. CTDIvol also showed high linear correlations with physical measurement-based indices, whereas the correlation coefficients were lower than for WED and ED. Among the physical measurement-based indices, weight/height showed the strongest correlations, followed by weight. Compared to CTDIvol, the correlation coefficients with DLP tended to be lower for WED, ED, and weight/height and higher for weight. The standard CTDIvol values at 60 kg and dose increase ratios with increasing weight, estimated using the regression equations, differed among scanners. Radiation dose indices closely correlated with body size indices such as WED, ED, weight/height, and weight. The relationships between dose and body size differed among scanners, indicating the significance of dose management considering body size.
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Affiliation(s)
- Yusuke Inoue
- Department of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, Japan
| | - Hiroyasu Itoh
- Department of Radiology, Kitasato University Hospital, Sagamihara 252-0375, Japan
| | - Kazunori Nagahara
- Department of Radiology, Kitasato University Hospital, Sagamihara 252-0375, Japan
| | - Hirofumi Hata
- Department of Radiology, Kitasato University Hospital, Sagamihara 252-0375, Japan
| | - Kohei Mitsui
- Department of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, Japan
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De Monte F, Sapignoli S, Laura Cortinovis A, Di Maggio A, Nardin M, Pizzirani E, Scagliori E, Volpe A, Paiusco M, Roggio A. Effectiveness of body size stratification for patient exposure optimization in Computed Tomography. Eur J Radiol 2023; 163:110804. [PMID: 37043885 DOI: 10.1016/j.ejrad.2023.110804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/23/2023] [Accepted: 03/26/2023] [Indexed: 03/31/2023]
Abstract
PURPOSE To establish size-dependent DRL and to estimate the effectiveness of the size-dependent DRLs over size-independent DRLs for a CT exposure optimization process. METHODS The study included 16,933 adult CT body examinations of the most common CT protocols. Acquisitions were included following an image quality assessment. Patients were grouped into five different classes by means of the water equivalent diameter (Dw): 21 ≤ Dw < 25, 25 ≤ Dw < 29, 29 ≤ Dw < 33,33 ≤ Dw < 37 (in cm). CTDIvol, DLP, DLPtot. and SSDE median values were provided both for the sample as a whole (size-independent approach) and for each Dw class (size-dependent approach). The performance of the two approaches in classifying sub-optimal examinations was evaluated through the confusion matrix and Matthews Correlation Coefficient (MCC) metric. The 75th percentile of the CTDIvol distribution was arbitrarily chosen as a threshold level above which the acquisitions are considered sub-optimal. RESULTS CTDIvol, DLP, DLPtot and SSDE typical values (median values) are statistically different across Dw groups. The confusion matrix analysis suggests that size-independent DRL could not mark potential suboptimal protocols for small and large patients. The agreement between the size-dependent and size-independent methods is strong only for the most populous classes (MCC > 0.7). For small and large patients size-independent approach fails to identify as sub-optimal around 20 % of the acquisition (MCC≪0.2). CONCLUSIONS It was proven by means of the confusion matrix and MCC metric that stratifying DRLs by patient size, size-dependent DRL can be a powerful strategy in order to improve the dose optimization process shown that a size-independent DRL fails to identify sub-optimal examinations for small and large patients.
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Albahiti SK, Barnawi RA, Alsafi K, Khafaji M, Aljondi R, Alghamdi SS, Awan Z, Sulieman A, Jafer M, Tamam N, Tajaldeen A, Mattar EH, Al-Malki KM, Bradley D. Establishment of institutional diagnostic reference levels for 6 adult computed tomography examinations: Results from preliminary data collection. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Li X, Steigerwalt D, Rehani MM. T-shirt size as a classification for body habitus in computed tomography (CT) and development of size-based dose reference levels for different indications. Eur J Radiol 2022; 151:110289. [PMID: 35397408 DOI: 10.1016/j.ejrad.2022.110289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 03/25/2022] [Accepted: 03/31/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE To examine the impact of patient size on dose indices and develop size-based reference levels (50th and 75th percentiles) for 20 body CT exams for routine and organ-specific clinical indications. METHODS Based on effective diameter estimated from adult body CT, each acquisition was classified into T-shirt size as XXS, XS, S, M, L, XL, and XXL. Radiation dose indices for each size and each exam type were correlated. RESULTS About 0.93 million CT exams from 256 CT facilities in the United States were analysed. Taking T-shirt size M as a reference, the CTDIvol for other sizes were: XXS (∼60%), XS (∼65%), S (∼75%), L (∼130%), XL (∼165%), XXL (∼210%), or grossly small patients received about 60% of the dose as compared to M sized patients and XXL required doubling the dose. Taking ratio of the dose indices of the largest to smallest size, it was evident that SSDE variation was much less (about 50%) than that in CTDIvol, but there was still nearly 40 to 220% variation in SSDE across the range of t-shirt sizes. The 50th and 75th percentile values are presented for CTDIvol, SSDE and DLP for each of the 20 CT exams and for each of the seven T-shirt sizes. CONCLUSIONS A novel approach expressing body habitus in terms of T-shirt size is not only simple and intuitive, but it also provides a tool to have a perception of differences in dose metrices among patients of different body build.
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Affiliation(s)
- Xinhua Li
- Massachusetts General Hospital, 55 Fruit Str, Boston, MA 02114, USA
| | | | - Madan M Rehani
- Massachusetts General Hospital, 55 Fruit Str, Boston, MA 02114, USA.
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Multiphase vascular lower limb computed tomography: Assessment of patients doses and radiogenic risk. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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