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Bak SH, Park J, Lee S, Kim JH, Lee HY, Park JY. Clinical usability of 3D gradient-echo-based ultrashort echo time imaging: Is it enough to facilitate diagnostic decision in real-world practice? PLoS One 2024; 19:e0296696. [PMID: 38722966 PMCID: PMC11081383 DOI: 10.1371/journal.pone.0296696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 12/17/2023] [Indexed: 05/13/2024] Open
Abstract
BACKGROUND With recent advances in magnetic resonance imaging (MRI) technology, the practical role of lung MRI is expanding despite the inherent challenges of the thorax. The purpose of our study was to evaluate the current status of the concurrent dephasing and excitation (CODE) ultrashort echo-time sequence and the T1-weighted volumetric interpolated breath-hold examination (VIBE) sequence in the evaluation of thoracic disease by comparing it with the gold standard computed tomography (CT). METHODS Twenty-four patients with lung cancer and mediastinal masses underwent both CT and MRI including T1-weighted VIBE and CODE. For CODE images, data were acquired in free breathing and end-expiratory images were reconstructed using retrospective respiratory gating. All images were evaluated through qualitative and quantitative approaches regarding various anatomical structures and lesions (nodule, mediastinal mass, emphysema, reticulation, honeycombing, bronchiectasis, pleural plaque and lymphadenopathy) inside the thorax in terms of diagnostic performance in making specific decisions. RESULTS Depiction of the lung parenchyma, mediastinal and pleural lesion was not significant different among the three modalities (p > 0.05). Intra-tumoral and peritumoral features of lung nodules were not significant different in the CT, VIBE or CODE images (p > 0.05). However, VIBE and CODE had significantly lower image quality and poorer depiction of airway, great vessels, and emphysema compared to CT (p < 0.05). Image quality of central airways and depiction of bronchi were significantly better in CODE than in VIBE (p < 0.001 and p = 0.005). In contrast, the depiction of the vasculature was better for VIBE than CODE images (p = 0.003). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were significant greater in VIBE than CODE except for SNRlung and SNRnodule (p < 0.05). CONCLUSIONS Our study showed the potential of CODE and VIBE sequences in the evaluation of localized thoracic abnormalities including solid pulmonary nodules.
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Affiliation(s)
- So Hyeon Bak
- Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Jinil Park
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, Republic of Korea
| | - Seokwon Lee
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| | - Jong Hee Kim
- Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Ho Yun Lee
- Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Seoul, Korea
| | - Jang-Yeon Park
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea
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Yoo SJ, Park YS, Choi H, Kim DS, Goo JM, Yoon SH. Prospective evaluation of deep learning image reconstruction for Lung-RADS and automatic nodule volumetry on ultralow-dose chest CT. PLoS One 2024; 19:e0297390. [PMID: 38386632 PMCID: PMC10883577 DOI: 10.1371/journal.pone.0297390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 01/04/2024] [Indexed: 02/24/2024] Open
Abstract
PURPOSE To prospectively evaluate whether Lung-RADS classification and volumetric nodule assessment were feasible with ultralow-dose (ULD) chest CT scans with deep learning image reconstruction (DLIR). METHODS The institutional review board approved this prospective study. This study included 40 patients (mean age, 66±12 years; 21 women). Participants sequentially underwent LDCT and ULDCT (CTDIvol, 0.96±0.15 mGy and 0.12±0.01 mGy) scans reconstructed with the adaptive statistical iterative reconstruction-V 50% (ASIR-V50) and DLIR. CT image quality was compared subjectively and objectively. The pulmonary nodules were assessed visually by two readers using the Lung-RADS 1.1 and automatically using a computerized assisted tool. RESULTS DLIR provided a significantly higher signal-to-noise ratio for LDCT and ULDCT images than ASIR-V50 (all P < .001). In general, DLIR showed superior subjective image quality for ULDCT images (P < .001) and comparable quality for LDCT images compared to ASIR-V50 (P = .01-1). The per-nodule sensitivities of observers for Lung-RADS category 3-4 nodules were 70.6-88.2% and 64.7-82.4% for DLIR-LDCT and DLIR-ULDCT images (P = 1) and categories were mostly concordant within observers. The per-nodule sensitivities of the computer-assisted detection for nodules ≥4 mm were 72.1% and 67.4% on DLIR-LDCT and ULDCT images (P = .50). The 95% limits of agreement for nodule volume differences between DLIR-LDCT and ULDCT images (-85.6 to 78.7 mm3) was similar to the within-scan nodule volume differences between DLIR- and ASIR-V50-LDCT images (-63.9 to 78.5 mm3), with volume differences smaller than 25% in 88.5% and 92.3% of nodules, respectively (P = .65). CONCLUSION DLIR enabled comparable Lung-RADS and volumetric nodule assessments on ULDCT images to LDCT images.
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Affiliation(s)
- Seung-Jin Yoo
- Department of Radiology, Hanyang University Medical Center, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Young Sik Park
- Department of Internal Medicine, Seoul National University Hospital, Seoul National College of Medicine, Seoul, Korea
| | - Hyewon Choi
- Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, South Korea
| | - Da Som Kim
- Departments of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Jin Mo Goo
- Department of radiology, Seoul National University Hospital, Seoul National College of Medicine, Seoul, Korea
| | - Soon Ho Yoon
- Department of radiology, Seoul National University Hospital, Seoul National College of Medicine, Seoul, Korea
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Wang J, Sui X, Zhao R, Du H, Wang J, Wang Y, Qin R, Lu X, Ma Z, Xu Y, Jin Z, Song L, Song W. Value of deep learning reconstruction of chest low-dose CT for image quality improvement and lung parenchyma assessment on lung window. Eur Radiol 2024; 34:1053-1064. [PMID: 37581663 DOI: 10.1007/s00330-023-10087-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 06/14/2023] [Accepted: 06/30/2023] [Indexed: 08/16/2023]
Abstract
OBJECTIVES To explore the performance of low-dose computed tomography (LDCT) with deep learning reconstruction (DLR) for the improvement of image quality and assessment of lung parenchyma. METHODS Sixty patients underwent chest regular-dose CT (RDCT) followed by LDCT during the same examination. RDCT images were reconstructed with hybrid iterative reconstruction (HIR) and LDCT images were reconstructed with HIR and DLR, both using lung algorithm. Radiation exposure was recorded. Image noise, signal-to-noise ratio, and subjective image quality of normal and abnormal CT features were evaluated and compared using the Kruskal-Wallis test with Bonferroni correction. RESULTS The effective radiation dose of LDCT was significantly lower than that of RDCT (0.29 ± 0.03 vs 2.05 ± 0.65 mSv, p < 0.001). The mean image noise ± standard deviation was 33.9 ± 4.7, 39.6 ± 4.3, and 31.1 ± 3.2 HU in RDCT, LDCT HIR-Strong, and LDCT DLR-Strong, respectively (p < 0.001). The overall image quality of LDCT DLR-Strong was significantly better than that of LDCT HIR-Strong (p < 0.001) and comparable to that of RDCT (p > 0.05). LDCT DLR-Strong was comparable to RDCT in evaluating solid nodules, increased attenuation, linear opacity, and airway lesions (all p > 0.05). The visualization of subsolid nodules and decreased attenuation was better with DLR than with HIR in LDCT but inferior to RDCT (all p < 0.05). CONCLUSION LDCT DLR can effectively reduce image noise and improve image quality. LDCT DLR provides good performance for evaluating pulmonary lesions, except for subsolid nodules and decreased lung attenuation, compared to RDCT-HIR. CLINICAL RELEVANCE STATEMENT The study prospectively evaluated the contribution of DLR applied to chest low-dose CT for image quality improvement and lung parenchyma assessment. DLR can be used to reduce radiation dose and keep image quality for several indications. KEY POINTS • DLR enables LDCT maintaining image quality even with very low radiation doses. • Chest LDCT with DLR can be used to evaluate lung parenchymal lesions except for subsolid nodules and decreased lung attenuation. • Diagnosis of pulmonary emphysema or subsolid nodules may require higher radiation doses.
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Affiliation(s)
- Jinhua Wang
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China
| | - Xin Sui
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China
| | - Ruijie Zhao
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China
| | - Huayang Du
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China
| | - Jiaru Wang
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China
| | - Yun Wang
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China
| | - Ruiyao Qin
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China
| | - Xiaoping Lu
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China
| | - Zhuangfei Ma
- Canon Medical System (China), No. 10, Jiuxianqiao North Road, Chaoyang District, Beijing, 100024, China
| | - Yinghao Xu
- Canon Medical System (China), No. 10, Jiuxianqiao North Road, Chaoyang District, Beijing, 100024, China
| | - Zhengyu Jin
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China
| | - Lan Song
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China.
| | - Wei Song
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing, 100730, China.
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Potočnik J, Foley S, Thomas E. Current and potential applications of artificial intelligence in medical imaging practice: A narrative review. J Med Imaging Radiat Sci 2023; 54:376-385. [PMID: 37062603 DOI: 10.1016/j.jmir.2023.03.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/25/2023] [Accepted: 03/28/2023] [Indexed: 04/18/2023]
Abstract
BACKGROUND AND PURPOSE Artificial intelligence (AI) is present in many areas of our lives. Much of the digital data generated in health care can be used for building automated systems to bring improvements to existing workflows and create a more personalised healthcare experience for patients. This review outlines select current and potential AI applications in medical imaging practice and provides a view of how diagnostic imaging suites will operate in the future. Challenges associated with potential applications will be discussed and healthcare staff considerations necessary to benefit from AI-enabled solutions will be outlined. METHODS Several electronic databases, including PubMed, ScienceDirect, Google Scholar, and University College Dublin Library Database, were used to identify relevant articles with a Boolean search strategy. Textbooks, government sources and vendor websites were also considered. RESULTS/DISCUSSION Many AI-enabled solutions in radiographic practice are available with more automation on the horizon. Traditional workflow will become faster, more effective, and more user friendly. AI can handle administrative or technical types of work, meaning it is applicable across all aspects of medical imaging practice. CONCLUSION AI offers significant potential to automate most of the manual tasks, ensure service consistency, and improve patient care. Radiographers, radiation therapists, and clinicians should ensure they have adequate understanding of the technology to enable ethical oversight of its implementation.
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Affiliation(s)
- Jaka Potočnik
- University College Dublin School of Medicine, Radiography & Diagnostic Imaging, Room A223, Belfield, Dublin 4, Ireland.
| | - Shane Foley
- University College Dublin School of Medicine, Radiography & Diagnostic Imaging, Room A223, Belfield, Dublin 4, Ireland
| | - Edel Thomas
- University College Dublin School of Medicine, Radiography & Diagnostic Imaging, Room A223, Belfield, Dublin 4, Ireland
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Milanese G, Ledda RE, Sabia F, Ruggirello M, Sestini S, Silva M, Sverzellati N, Marchianò AV, Pastorino U. Ultra-low dose computed tomography protocols using spectral shaping for lung cancer screening: Comparison with low-dose for volumetric LungRADS classification. Eur J Radiol 2023; 161:110760. [PMID: 36878153 DOI: 10.1016/j.ejrad.2023.110760] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/17/2023] [Accepted: 02/23/2023] [Indexed: 03/03/2023]
Abstract
PURPOSE To compare Low-Dose Computed Tomography (LDCT) with four different Ultra-Low-Dose Computed Tomography (ULDCT) protocols for PN classification according to the Lung Reporting and Data System (LungRADS). METHODS Three hundred sixty-one participants of an ongoing lung cancer screening (LCS) underwent single-breath-hold double chest Computed Tomography (CT), including LDCT (120kVp, 25mAs; CTDIvol 1,62 mGy) and one ULDCT among: fully automated exposure control ("ULDCT1"); fixed tube-voltage and current according to patient size ("ULDCT2"); hybrid approach with fixed tube-voltage ("ULDCT3") and tube current automated exposure control ("ULDCT4"). Two radiologists (R1, R2) assessed LungRADS 2022 categories on LDCT, and then after 2 weeks on ULDCT using two different kernels (R1: Qr49ADMIRE 4; R2: Br49ADMIRE 3). Intra-subject agreement for LungRADS categories between LDCT and ULDCT was measured by the k-Cohen Index with Fleiss-Cohen weights. RESULTS LDCT-dominant PNs were detected in ULDCT in 87 % of cases on Qr49ADMIRE 4 and 88 % on Br49ADMIRE 3. The intra-subject agreement was: κULDCT1 = 0.89 [95 %CI 0.82-0.96]; κULDCT2 = 0.90 [0.81-0.98]; κULDCT3 = 0.91 [0.84-0.99]; κULDCT4 = 0.88 [0.78-0.97] on Qr49ADMIRE 4, and κULDCT1 = 0.88 [0.80-0.95]; κULDCT2 = 0.91 [0.86-0.96]; κULDCT3 = 0.87 [0.78-0.95]; and κULDCT4 = 0.88 [0.82-0.94] on Br49ADMIRE 3. LDCT classified as LungRADS 4B were correctly identified as LungRADS 4B at ULDCT3, with the lowest radiation exposure among the tested protocols (median effective doses were 0.31, 0.36, 0.27 and 0.37 mSv for ULDCT1, ULDCT2, ULDCT3, and ULDCT4, respectively). CONCLUSIONS ULDCT by spectral shaping allows the detection and characterization of PNs with an excellent agreement with LDCT and can be proposed as a feasible approach in LCS.
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Affiliation(s)
- Gianluca Milanese
- Scienze Radiologiche, Department of Medicine and Surgery, University of Parma, Parma, Italy; Fondazione IRCCS Istituto Nazionale dei Tumori, Thoracic Surgery, Milan, Lombardia, Italy.
| | - Roberta Eufrasia Ledda
- Scienze Radiologiche, Department of Medicine and Surgery, University of Parma, Parma, Italy; Fondazione IRCCS Istituto Nazionale dei Tumori, Thoracic Surgery, Milan, Lombardia, Italy.
| | - Federica Sabia
- Fondazione IRCCS Istituto Nazionale dei Tumori, Thoracic Surgery, Milan, Lombardia, Italy.
| | - Margherita Ruggirello
- Fondazione IRCCS Istituto Nazionale dei Tumori, Department of Diagnostic Imaging and Radiotherapy, Milan, Italy.
| | - Stefano Sestini
- Fondazione IRCCS Istituto Nazionale dei Tumori, Thoracic Surgery, Milan, Lombardia, Italy.
| | - Mario Silva
- Scienze Radiologiche, Department of Medicine and Surgery, University of Parma, Parma, Italy.
| | - Nicola Sverzellati
- Scienze Radiologiche, Department of Medicine and Surgery, University of Parma, Parma, Italy.
| | - Alfonso Vittorio Marchianò
- Fondazione IRCCS Istituto Nazionale dei Tumori, Department of Diagnostic Imaging and Radiotherapy, Milan, Italy.
| | - Ugo Pastorino
- Fondazione IRCCS Istituto Nazionale dei Tumori, Thoracic Surgery, Milan, Lombardia, Italy.
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Uemura R, Nagatani Y, Hashimoto M, Oshio Y, Sonoda A, Otani H, Hanaoka J, Watanabe Y. Association of Respiratory Functional Indices and Smoking with Pleural Movement and Mean Lung Density Assessed Using Four-Dimensional Dynamic-Ventilation Computed Tomography in Smokers and Patients with COPD. Int J Chron Obstruct Pulmon Dis 2023; 18:327-339. [PMID: 36945706 PMCID: PMC10024907 DOI: 10.2147/copd.s389075] [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: 10/01/2022] [Accepted: 02/02/2023] [Indexed: 03/17/2023] Open
Abstract
Purpose To correlate the ratio of the non-dependent to dependent aspects of the maximal pleural movement vector (MPMVND/D) and gravity-oriented collapse ratio (GCRND/D), and the mean lung field density (MLD) obtained using four-dimensional (4D) dynamic-ventilation computed tomography (DVCT) with airflow limitation parameters and the Brinkman index. Materials and Methods Forty-seven patients, including 22 patients with COPD, 13 non-COPD smokers, and 12 non-smokers, with no/slight pleural adhesion confirmed using a thoracoscope, underwent 4D-DVCT with 16 cm coverage. Coordinates for the lung field center, as well as ventral and dorsal pleural points, set on the central trans-axial levels in the median and para-median sagittal planes at end-inspiration, were automatically measured (13-17 frame images, 0.35 seconds/frame). MPMVND/D and GCRND/D were calculated based on MPMV and GCR values for all the included points and the lung field center. MLD was automatically measured in each of the time frames, and the maximal change ratio of MLD (MLDCR) was calculated. These measured values were compared among COPD patients, non-COPD smokers, and non-smokers, and were correlated with the Brinkman index, FEV1/FVC, FEV1 predicted, RV/TLC, and FEF25-75% using Spearman's rank coefficients. Results MPMVND/D was highest in non-smokers (0.819±0.464), followed by non-COPD smokers (0.405±0.131) and patients with COPD (-0.219±0.900). GCRND/D in non-smokers (1.003±1.384) was higher than that in patients with COPD (-0.164±1.199). MLDCR in non-COPD smokers (0.105±0.028) was higher than that in patients with COPD (0.078±0.027). MPMVND/D showed positive correlations with FEV1 predicted (r=0.397, p=0.006), FEV1/FVC (r=0.501, p<0.001), and FEF25-75% (r=0.368, p=0.012). GCRND/D also demonstrated positive correlations with FEV1 (r=0.397, p=0.006), FEV1/FVC (r=0.445, p=0.002), and FEF25-75% (r=0.371, p=0.011). MPMVND/D showed a negative correlation with the Brinkman index (r=-0.398, p=0.006). Conclusion We demonstrated that reduced MPMVND/D and GCRND/D were associated with respiratory functional indices, in addition to a negative association of MPMVND/D with the Brinkman index, which should be recognized when assessing local pleural adhesion on DVCT, especially for ventral pleural aspects.
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Affiliation(s)
- Ryo Uemura
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
- Correspondence: Ryo Uemura; Yukihiro Nagatani, Department of Radiology, Shiga University of Medical Science, Seta-tsukinowa-cho, Otsu, Shiga, Japan, 520-2192, Tel/Fax +81-77-548-2536, Email ;
| | - Yukihiro Nagatani
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Masayuki Hashimoto
- Department of Thoracic Surgery, Kyoto Medical Center, Kyoto, Kyoto, Japan
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Yasuhiko Oshio
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Akinaga Sonoda
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Hideji Otani
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Jun Hanaoka
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Yoshiyuki Watanabe
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
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Liver Attenuation Assessment in Reduced Radiation Chest Computed Tomography. J Comput Assist Tomogr 2022; 46:682-687. [PMID: 35675689 DOI: 10.1097/rct.0000000000001340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE This study aimed to evaluate the reliability of liver and spleen Hounsfield units (HU) measurements in reduced radiation computed tomography (RRCT) of the chest within the sub-millisievert range. METHODS We performed a prospective, institutional review board-approved study of accrued patients who underwent unenhanced normal-dose chest CT (NDCT) and with an average radiation dose of less than 5% of NDCT. In-house artificial intelligence-based denoising methods produced 2 denoised RRCT (dRRCT) series. Hepatic and splenic attenuations were measured on all 4 series: NDCT, RRCT, dRRCT1, and dRRCT2. Statistical analyses assessed the differences between the HU measurements of the liver and spleen in RRCTs and NDCT. As a test case, we assessed the performance of RRCTs for fatty liver detection, considering NDCT to be the reference standard. RESULTS Wilcoxon test compared liver and spleen attenuation in the 72 patients included in our cohort. The liver attenuation in NDCT (median, 59.38 HU; interquartile range, 55.00-66.06 HU) was significantly different from the attenuation in RRCT, dRRCT1, and dRRCT2 (median, 63.63, 42.00, and 33.67 HU; interquartile range, 56.19-67.19, 37.33-45.83, and 30.33-38.50 HU, respectively), all with a P value <0.01. Six patients (8.3%) were considered to have fatty liver on NDCT. The specificity, sensitivity, and accuracy of fatty liver detection by RRCT were greater than 98.5%, 50%, and 94.3%, respectively. CONCLUSIONS Attenuation measurements were significantly different between NDCT and RRCTs, but may still have diagnostic value in appreciating hepatosteastosis. Abdominal organ attenuation on RRCT protocols may differ from attenuation on NDCT and should be validated when new low-dose protocols are used.
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Cilleruelo Ramos Á, Figueroa Almánzar S, López Castro R, Martínez Hernández NJ, Mezquita Pérez L, Moreno Casado P, Zabaleta Jiménez J. Spanish Society of Thoracic Surgery (SECT) consensus document. Long-term follow-up for operated patients with lung cancer. Cir Esp 2022; 100:320-328. [PMID: 35643357 DOI: 10.1016/j.cireng.2022.05.024] [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: 05/15/2021] [Accepted: 08/02/2021] [Indexed: 06/15/2023]
Abstract
The most effective treatment for lung cancer is complete lung resection, although recurrences reach up to 10% and the appearance of second neoplasms, up to 6%. Therefore, the follow-up of these patients will be essential for the early detection and treatment of these events; however there is no definition of the form, time and cadence of these follow-ups. In this consensus document, we try to define them based on the available scientific evidence. A critical review of the literature is carried out (meta-analysis, systematic reviews, reviews, consensus recommendations of scientific societies, randomized controlled studies, non-randomized controlled studies, observational studies and case series studies) and communications to the main congresses on oncology and thoracic surgery in Spanish, English and French. The evidences found are classified following the GRADE system. It is defined according to the existing evidence that the patient resected for lung cancer should be followed up, as well as that this follow-up should be close during the first years and with CT (not being necessary to follow up with PET-CT, biomarkers or bronchoscopy). Cessation of smoking is also recommended in this follow-up.
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Affiliation(s)
- Ángel Cilleruelo Ramos
- Servicio de Cirugía Torácica, Hospital Clínico Universitario de Valladolid, Valladolid, Spain.
| | | | - Rafael López Castro
- Servicio de Oncología Médica, Hospital Clínico Universitario de Valladolid, Valladolid, Spain
| | | | | | - Paula Moreno Casado
- Servicio de Cirugía Torácica, Hospital Universitario Reina Sofía de Córdoba, Córdoba, Spain
| | - Jon Zabaleta Jiménez
- Servicio de Cirugía Torácica, Hospital Universitario de Donostia, San Sebastián, San Sebastián, Spain
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Detection of Incidental Nonosseous Thoracic Pathology on State-of-the-Art Ultralow-Dose Protocol Computed Tomography in Pediatric Patients With Pectus Excavatum. J Comput Assist Tomogr 2022; 46:492-498. [DOI: 10.1097/rct.0000000000001285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Cilleruelo Ramos Á, Figueroa Almánzar S, López Castro R, Martínez Hernández NJ, Mezquita Pérez L, Moreno Casado P, Zabaleta Jiménez J. Spanish Society of Thoracic Surgery (SECT) consensus document. Long-term follow-up for operated patients with lung cancer. Cir Esp 2021; 100:S0009-739X(21)00250-5. [PMID: 34521509 DOI: 10.1016/j.ciresp.2021.08.003] [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: 05/15/2021] [Revised: 06/27/2021] [Accepted: 08/02/2021] [Indexed: 10/20/2022]
Abstract
The most effective treatment for lung cancer is complete lung resection, although recurrences reach up to 10% and the appearance of second neoplasms, up to 6%. Therefore, the follow-up of these patients will be essential for the early detection and treatment of these events; however, there is no definition of the form, time and cadence of these follow-ups. In this consensus document, we try to define them based on the available scientific evidence. A critical review of the literature is carried out (meta-analysis, systematic reviews, reviews, consensus recommendations of scientific societies, randomized controlled studies, non-randomized controlled studies, observational studies and case series studies) and communications to the main congresses on oncology and thoracic surgery in Spanish, English and French. The evidences found are classified following the GRADE system. It is defined according to the existing evidence that the patient resected for lung cancer should be followed up, as well as that this follow-up should be close during the first years and with CT (not being necessary to follow up with PET-CT, biomarkers or bronchoscopy). Cessation of smoking is also recommended in this follow-up.
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Affiliation(s)
- Ángel Cilleruelo Ramos
- Servicio de Cirugía Torácica, Hospital Clínico Universitario de Valladolid, Valladolid, España.
| | | | - Rafael López Castro
- Servicio de Oncología Médica. Hospital Clínico Universitario de Valladolid, Valladolid, España
| | | | | | - Paula Moreno Casado
- Servicio de Cirugía Torácica. Hospital Universitario Reina Sofía de Córdoba, Córdoba, España
| | - Jon Zabaleta Jiménez
- Servicio de Cirugía Torácica. Hospital Universitario de Donostia, San Sebastián, San Sebastián, España
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Impact of Morphotype on Image Quality and Diagnostic Performance of Ultra-Low-Dose Chest CT. J Clin Med 2021; 10:jcm10153284. [PMID: 34362068 PMCID: PMC8348164 DOI: 10.3390/jcm10153284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/22/2021] [Accepted: 07/22/2021] [Indexed: 11/23/2022] Open
Abstract
Objectives: The image quality of an Ultra-Low-Dose (ULD) chest CT depends on the patient’s morphotype. We hypothesize that there is a threshold beyond which the diagnostic performance of a ULD chest CT is too degraded. This work assesses the influence of morphotype (Body Mass Index BMI, Maximum Transverse Chest Diameter MTCD and gender) on image quality and the diagnostic performance of a ULD chest CT. Methods: A total of 170 patients from three prior prospective monocentric studies were retrospectively included. Renewal of consent was waived by our IRB. All the patients underwent two consecutive unenhanced chest CT acquisitions with a full dose (120 kV, automated tube current modulation) and a ULD (135 kV, fixed tube current at 10 mA). Image noise, subjective image quality and diagnostic performance for nine predefined lung parenchyma lesions were assessed by two independent readers, and correlations with the patient’s morphotype were sought. Results: The mean BMI was 26.6 ± 5.3; 20.6% of patients had a BMI > 30. There was a statistically significant negative correlation of the BMI with the image quality (ρ = −0.32; IC95% = (−0.468; −0.18)). The per-patient diagnostic performance of ULD was sensitivity, 77%; specificity, 99%; PPV, 94% and NPV, 65%. There was no statistically significant influence of the BMI, the MTCD nor the gender on the per-patient and per-lesion diagnostic performance of a ULD chest CT, apart from a significant negative correlation for the detection of emphysema. Conclusions: Despite a negative correlation between the BMI and the image quality of a ULD chest CT, we did not find a correlation between the BMI and the diagnostic performance of the examination, suggesting a possible use of the ULD protocol in obese patients.
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Dosimetry and Comparison between Different CT Protocols (Low Dose, Ultralow Dose, and Conventional CT) for Lung Nodules' Detection in a Phantom. Radiol Res Pract 2021; 2021:6667779. [PMID: 33552601 PMCID: PMC7847358 DOI: 10.1155/2021/6667779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/03/2021] [Accepted: 01/16/2021] [Indexed: 12/17/2022] Open
Abstract
Background The effects of dose reduction in lung nodule detection need better understanding. Purpose To compare the detection rate of simulated lung nodules in a chest phantom using different computed tomography protocols, low dose (LD), ultralow dose (ULD), and conventional (CCT), and to quantify their respective amount of radiation. Materials and Methods A chest phantom containing 93 simulated lung nodules was scanned using five different protocols: ULD (80 kVp/30 mA), LD A (120 kVp/20 mA), LD B (100 kVp/30 mA), LD C (120 kVp/30 mA), and CCT (120 kVp/automatic mA). Four chest radiologists analyzed a selected image from each protocol and registered in diagrams the nodules they detected. Kruskal-Wallis and McNemar's tests were performed to determine the difference in nodule detection. Equivalent doses were estimated by placing thermoluminescent dosimeters on the surface and inside the phantom. Results There was no significant difference in lung nodules' detection when comparing ULD and LD protocols (p=0.208 to p=1.000), but there was a significant difference when comparing each one of those against CCT (p < 0.001). The detection rate of nodules with CT attenuation values lower than -600 HU was also different when comparing all protocols against CCT (p < 0.001 to p=0.007). There was at least moderate agreement between observers in all protocols (κ-value >0.41). Equivalent dose values ranged from 0.5 to 9 mSv. Conclusion There is no significant difference in simulated lung nodules' detection when comparing ULD and LD protocols, but both differ from CCT, especially when considering lower-attenuating nodules.
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Liew CJY, Leong LCH, Teo LLS, Ong CC, Cheah FK, Tham WP, Salahudeen HMM, Lee CH, Kaw GJL, Tee AKH, Tsou IYY, Tay KH, Quah R, Tan BP, Chou H, Tan D, Poh ACC, Tan AGS. A practical and adaptive approach to lung cancer screening: a review of international evidence and position on CT lung cancer screening in the Singaporean population by the College of Radiologists Singapore. Singapore Med J 2020; 60:554-559. [PMID: 31781779 DOI: 10.11622/smedj.2019145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Lung cancer is the leading cause of cancer-related death around the world, being the top cause of cancer-related deaths among men and the second most common cause of cancer-related deaths among women in Singapore. Currently, no screening programme for lung cancer exists in Singapore. Since there is mounting evidence indicating a different epidemiology of lung cancer in Asian countries, including Singapore, compared to the rest of the world, a unique and adaptive approach must be taken for a screening programme to be successful at reducing mortality while maintaining cost-effectiveness and a favourable risk-benefit ratio. This review article promotes the use of low-dose computed tomography of the chest and explores the radiological challenges and future directions.
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Affiliation(s)
| | | | - Lynette Li San Teo
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - Ching Ching Ong
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - Foong Koon Cheah
- Department of Diagnostic Radiology, Singapore General Hospital, Singapore
| | - Wei Ping Tham
- Department of Diagnostic Radiology, Singapore General Hospital, Singapore
| | | | - Chau Hung Lee
- Department of Diagnostic Radiology, Tan Tock Seng Hospital, Singapore
| | | | - Augustine Kim Huat Tee
- Department of Respiratory and Critical Care Medicine, Changi General Hospital, Singapore
| | - Ian Yu Yan Tsou
- Department of Diagnostic Radiology, Mount Elizabeth Hospital, Singapore
| | - Kiang Hiong Tay
- Department of Diagnostic Radiology, Singapore General Hospital, Singapore
| | - Raymond Quah
- Department of Diagnostic Radiology, Farrer Park Hospital, Singapore
| | - Bien Peng Tan
- Department of Diagnostic Radiology, Tan Tock Seng Hospital, Singapore
| | - Hong Chou
- Department of Diagnostic Radiology, Khoo Teck Puat Hospital, Singapore
| | - Daniel Tan
- Department of Diagnostic Radiology Oncology, Farrer Park Hospital, Singapore
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Image reconstruction: Part 1 – understanding filtered back projection, noise and image acquisition. J Cardiovasc Comput Tomogr 2020; 14:219-225. [DOI: 10.1016/j.jcct.2019.04.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/04/2019] [Accepted: 04/15/2019] [Indexed: 11/23/2022]
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15
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Image Quality Measured From Ultra-Low Dose Chest Computed Tomography Examination Protocols Using 6 Different Iterative Reconstructions From 4 Vendors, a Phantom Study. J Comput Assist Tomogr 2020; 44:95-101. [DOI: 10.1097/rct.0000000000000947] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Added Value of Ultra-low-dose Computed Tomography, Dose Equivalent to Chest X-Ray Radiography, for Diagnosing Chest Pathology. J Thorac Imaging 2019; 34:179-186. [PMID: 30870305 PMCID: PMC6485307 DOI: 10.1097/rti.0000000000000404] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Purpose: The purpose of this study was to assess the clinical value of ultra–low-dose computed tomography (ULDCT) compared with chest x-ray radiography (CXR) for diagnosing chest pathology. Materials and Methods: A total of 200 patients referred for CXR by outpatient clinics or general practitioners were enrolled prospectively. They underwent CXR (posteroanterior and lateral) and ULDCT (120 kV, 3 mAs) on the same day. In-room time and effective dose were recorded for each examination. Studies were categorized whether they were diagnostic or not, relevant radiologic diagnostic findings were reported, and confidence for diagnosis was recorded by a Likert scale. Differences in diagnostic confidence and effect on management decision were compared. Results: In-room time was <2 minutes for CXR and <3 minutes for ULDCT. Effective dose was 0.040 mSv for CXR and 0.071 mSv for ULDCT. CXR was considered diagnostic in 98% and ULDCT in 100%. The mean perceived confidence for diagnosis was 88±12% with CXR and 98±2% with ULDCT (P<0.0001), whereas discrepant findings between CXR and ULDCT were found in 101 of 200 patients. As compared with CXR, ULDCT had added value for management decisions in 40 of 200 patients. Conclusions: ULDCT provided added value to the radiologist by improved perceived confidence with a reduction in false-positive and false-negative CXR investigations that had management implications in 20% of patients. The effective dose of ULDCT will not be a limiting factor for introducing ULDCT of the chest on a broad scale in clinical practice.
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Role of thoracic imaging in the management of lymphangioleiomyomatosis. Respir Med 2019; 157:14-20. [PMID: 31470185 DOI: 10.1016/j.rmed.2019.08.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/16/2019] [Accepted: 08/20/2019] [Indexed: 12/17/2022]
Abstract
Lymphangioleiomyomatosis (LAM) is a rare diffuse lung cystic disease (DLCD) that occurs sporadically or in association with Tuberous Sclerosis Complex (TSC). The diagnostic pathway is tracked on the identification of the disease hallmarks on chest High-Resolution Computed Tomography (HRCT). Aim of this review is to discuss the thoracic HRCT pathognomonic features, essential to rule out other DLCD. It also examines the new evidences emerging from Computed Tomography (CT) quantitative studies that, by demonstrating a specific cysts distribution and a pathological aspect of the parenchyma near the cysts, could improve our understanding of this rare disorder and supply pulmonologists with a new tool for a more appropriate long-term management. Finally, the contribution of other image techniques as low dose chest CT, Magnetic Resonance Imaging (MRI) and Ultrasound (US) is discussed.
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Meyer E, Labani A, Schaeffer M, Jeung MY, Ludes C, Meyer A, Roy C, Leyendecker P, Ohana M. Wide-volume versus helical acquisition in unenhanced chest CT: prospective intra-patient comparison of diagnostic accuracy and radiation dose in an ultra-low-dose setting. Eur Radiol 2019; 29:6858-6866. [PMID: 31175414 DOI: 10.1007/s00330-019-06278-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/15/2019] [Accepted: 05/17/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Diagnostic performance and potential radiation dose reduction of wide-area detector CT sequential acquisition ("wide-volume" acquisition (WV)) in unenhanced chest examination are unknown. This study aims to assess the image quality, the diagnostic performance, and the radiation dose reduction of WV mode compared with the classical helical acquisition for lung parenchyma analysis in an ultra-low-dose (ULD) protocol. METHODS After Institutional Review Board Approval and written informed consent, 64 patients (72% men; 67.6 ± 9.7 years old; BMI 26.1 ± 5.3 kg/m2) referred for a clinically indicated unenhanced chest CT were prospectively included. All patients underwent, in addition to a standard helical acquisition (120 kV, automatic tube current modulation), two ULD acquisitions (135 kV, fixed tube current at 10 mA): one in helical mode and one in WV mode. Image noise, subjective image quality (5-level Likert scale), and diagnostic performance for the detection of 9 predetermined parenchymal abnormalities were assessed by two radiologists and compared using the chi-square or Fisher non-parametric tests. RESULTS Subjective image quality (4.2 ± 0.7 versus 4.2 ± 0.8, p = 0.56), image noise (41.7 ± 8 versus 40.9 ± 8.7, p = 0.3), and diagnostic performance were equivalent between ULD WV and ULD helical. Radiation dose was significantly lower for the ULD WV acquisition (mean dose-length product 14.1 ± 1.3 mGy cm versus 15.8 ± 1.3, p < 0.0001). CONCLUSION An additional 11% dose reduction is achieved with the WV mode in ULD chest CT with fixed tube current, with equivalent image quality and diagnostic performance when compared with the helical acquisition. KEY POINTS • Image quality and diagnostic performance of ultra-low-dose unenhanced chest CT are identical between wide-volume mode and the reference helical acquisition. • Wide-volume mode allows an additional radiation dose reduction of 11% (mean dose-length product 14.1 ± 1.3 mGy cm versus 15.8 ± 1.3, p < 0.0001).
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Affiliation(s)
- Elsa Meyer
- Radiology Department, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67000, Strasbourg, France
| | - Aissam Labani
- Radiology Department, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67000, Strasbourg, France
| | - Mickaël Schaeffer
- Radiology Department, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67000, Strasbourg, France
| | - Mi-Young Jeung
- Radiology Department, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67000, Strasbourg, France
| | - Claire Ludes
- Radiology Department, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67000, Strasbourg, France
| | - Alain Meyer
- Physiology Department, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67000, Strasbourg, France
| | - Catherine Roy
- Radiology Department, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67000, Strasbourg, France
| | - Pierre Leyendecker
- Radiology Department, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67000, Strasbourg, France
| | - Mickaël Ohana
- Radiology Department, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67000, Strasbourg, France. .,ICube Laboratory, 300 Boulevard Sébastien Brandt, 67400, Illkirch Graffenstaden, France.
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Milanese G, Silva M, Frauenfelder T, Eberhard M, Sabia F, Martini C, Marchianò A, Prokop M, Sverzellati N, Pastorino U. Comparison of ultra-low dose chest CT scanning protocols for the detection of pulmonary nodules: a phantom study. TUMORI JOURNAL 2019; 105:394-403. [PMID: 31041885 DOI: 10.1177/0300891619847271] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE To test ultra-low-dose computed tomography (ULDCT) scanning protocols for the detection of pulmonary nodules (PN). METHODS A chest phantom containing 19 solid and 11 subsolid PNs was scanned on a third-generation dual-source computed tomography (CT) scanner. Five ULDCT scans (Sn100kVp and 120, 70, 50, 30, and 20 reference mAs, using tube current modulation), reconstructed with iterative reconstruction (IR) algorithm at strength levels 2, 3, 4, and 5, were compared with standard CT (120kVp, 150 reference mAs, using tube current modulation). PNs were subjectively assessed according to a 4-point scale: 0, nondetectable nodule; 1, detectable nodule, very unlikely to be correctly measured; 2, detectable nodule, likely to be correctly measured; 3, PN quality equal to standard of reference. PN scores were analysed according to the Lung Imaging Reporting and Data System (Lung-RADS), simulating detection of nodules at baseline and incidence screening round. RESULTS For the baseline round, there were 17 Lung-RADS 2, 4 Lung-RADS 3, 8 Lung-RADS 4A, and 1 Lung-RADS 4B PNs. They were detectable in any ULDCT protocol, with the exception of 1 nondetectable part-solid nodule in 1 scanning protocol (120 reference mAs; IR strength: 3). For the incidence round, there were 4 Lung-RADS 2, 14 Lung-RADS 3, 2 Lung-RADS 4A, and 10 Lung-RADS 4B PNs. Ten were nondetectable in at least one ULDCT dataset; however, they were at least detectable in ULDCT with 70 reference mAs (IR strength: 4 and 5). CONCLUSIONS ULDCT scanning protocols allowing the detection of PNs can be proposed for the purpose of lung cancer screening.
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Affiliation(s)
- Gianluca Milanese
- Division of Radiology, Department of Medicine and Surgery, University of Parma, Parma, Italy.,Department of Thoracic Surgery, IRCCS Istituto Nazionale Tumori, Milan, Italy
| | - Mario Silva
- Division of Radiology, Department of Medicine and Surgery, University of Parma, Parma, Italy.,Department of Thoracic Surgery, IRCCS Istituto Nazionale Tumori, Milan, Italy
| | - Thomas Frauenfelder
- Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland
| | - Matthias Eberhard
- Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland
| | - Federica Sabia
- Department of Thoracic Surgery, IRCCS Istituto Nazionale Tumori, Milan, Italy
| | - Chiara Martini
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Alfonso Marchianò
- Department of Radiology, IRCCS Istituto Nazionale Tumori, Milan, Italy
| | - Mathias Prokop
- Diagnostic Image Analysis Group, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Nicola Sverzellati
- Division of Radiology, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Ugo Pastorino
- Department of Thoracic Surgery, IRCCS Istituto Nazionale Tumori, Milan, Italy
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Yan C, Liang C, Xu J, Wu Y, Xiong W, Zheng H, Xu Y. Ultralow-dose CT with knowledge-based iterative model reconstruction (IMR) in evaluation of pulmonary tuberculosis: comparison of radiation dose and image quality. Eur Radiol 2019; 29:5358-5366. [PMID: 30927099 DOI: 10.1007/s00330-019-06129-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 02/06/2019] [Accepted: 03/06/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To evaluate the image quality of ultralow-dose computed tomography (ULDCT) reconstructed with knowledge-based iterative model reconstruction (IMR) in patients with pulmonary tuberculosis (TB). METHODS This IRB-approved prospective study enrolled 59 consecutive patients (mean age, 43.9 ± 16.6 years; F:M 18:41) with known or suspected pulmonary TB. Patients underwent a low-dose CT (LDCT) using automatic tube current modulation followed by an ULDCT using fixed tube current. Raw image data were reconstructed with filtered-back projection (FBP), hybrid iterative reconstruction (iDose), and IMR. Objective measurements including CT attenuation, image noise, and contrast-to-noise ratio (CNR) were assessed and compared using repeated-measures analysis of variance. Overall image quality and visualization of normal and pathological findings were subjectively scored on a five-point scale. Radiation output and subjective scores were compared by the paired Student t test and Wilcoxon signed-rank test, respectively. RESULTS Compared with FBP and iDose, IMR yielded significantly lower noise and higher CNR values at both dose levels (p < 0.01). Subjective ratings for pathological findings including centrilobular nodules, consolidation, tree-in-bud, and cavity were significantly better with ULDCT IMR images than those with LDCT iDose images (p < 0.01), but blurred edges were observed. With IMR implementation, a 59% reduction of the mean effective dose was achieved with ULDCT (0.28 ± 0.02 mSv) compared with LDCT (0.69 ± 0.15 mSv) without impairing image quality (p < 0.001). CONCLUSIONS IMR offers considerable noise reduction and improvement in image quality for patients with pulmonary TB undergoing chest ULDCT at an effective dose of 0.28 mSv. KEY POINTS • Radiation dose is a major concern for tuberculosis patients requiring repeated follow-up CT. • IMR allows substantial radiation dose reduction in chest CT without compromising image quality. • ULDCT reconstructed with IMR allows accurate depiction of CT features of pulmonary tuberculosis.
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Affiliation(s)
- Chenggong Yan
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Chunyi Liang
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Jun Xu
- Department of Hematology, Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Yuankui Wu
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Wei Xiong
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Huan Zheng
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Yikai Xu
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong, People's Republic of China.
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Feasibility of low-dose CT with spectral shaping and third-generation iterative reconstruction in evaluating interstitial lung diseases associated with connective tissue disease: an intra-individual comparison study. Eur Radiol 2019; 29:4529-4537. [DOI: 10.1007/s00330-018-5969-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/30/2018] [Accepted: 12/13/2018] [Indexed: 12/21/2022]
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High-pitch, 120 kVp/30 mAs, low-dose dual-source chest CT with iterative reconstruction: Prospective evaluation of radiation dose reduction and image quality compared with those of standard-pitch low-dose chest CT in healthy adult volunteers. PLoS One 2019; 14:e0211097. [PMID: 30677082 PMCID: PMC6345490 DOI: 10.1371/journal.pone.0211097] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 01/08/2019] [Indexed: 01/08/2023] Open
Abstract
PURPOSE Objective of this study was to evaluate the effectiveness of the iterative reconstruction of high-pitch dual-source chest CT (IR-HP-CT) scanned with low radiation exposure compared with low dose chest CT (LDCT). MATERIALS AND METHODS This study was approved by the institutional review board. Thirty healthy adult volunteers (mean age 44 years) were enrolled in this study. All volunteers underwent both IR-HP-CT and LDCT. IR-HP-CT was scanned with 120 kVp tube voltage, 30 mAs tube current and pitch 3.2 and reconstructed with sinogram affirmed iterative reconstruction. LDCT was scanned with 120 kVp tube voltage, 40 mAs tube current and pitch 0.8 and reconstructed with B50 filtered back projection. Image noise, and signal to noise ratio (SNR) of the infraspinatus muscle, subcutaneous fat and lung parenchyma were calculated. Cardiac motion artifact, overall image quality and artifacts was rated by two blinded readers using 4-point scale. The dose-length product (DLP) (mGy∙cm) were obtained from each CT dosimetry table. Scan length was calculated from the DLP results. The DLP parameter was a metric of radiation output, not of patient dose. Size-specific dose estimation (SSDE, mGy) was calculated using the sum of the anteroposterior and lateral dimensions and effective radiation dose (ED, mSv) were calculated using CT dosimetry index. RESULTS Approximately, mean 40% of SSDE (2.1 ± 0.2 mGy vs. 3.5 ± 0.3 mGy) and 34% of ED (1.0 ± 0.1 mSv vs. 1.5 ± 0.1 mSv) was reduced in IR-HP-CT compared to LDCT (P < 0.0001). Image noise was reduced in the IR-HP-CT (16.8 ± 2.8 vs. 19.8 ± 3.4, P = 0.0001). SNR of lung and aorta of IR-HP-CT showed better results compared with that of LDCT (22.2 ± 5.9 vs. 33.0 ± 7.8, 1.9 ± 0.4 vs 1.1 ± 0.3, P < 0.0001). The score of cardiac pulsation artifacts were significantly reduced on IR-HP-CT (3.8 ± 0.4, 95% confidence interval, 3.7‒4.0) compared with LDCT (1.6 ± 0.6, 95% confidence interval, 1.3‒1.8) (P < 0.0001). SNR of muscle and fat, beam hardening artifact and overall subjective image quality of the mediastinum, lung and chest wall were comparable on both scans (P ≥ 0.05). CONCLUSION IR-HP-CT with 120 kVp and 30 mAs tube setting in addition to an iterative reconstruction reduced cardiac motion artifact and radiation exposure while representing similar image quality compared with LDCT.
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O'Brien C, Kok HK, Kelly B, Kumamaru K, Sahadevan A, Lane S, Buckley O. To investigate dose reduction and comparability of standard dose CT vs Ultra low dose CT in evaluating pulmonary emphysema. Clin Imaging 2019; 53:115-119. [DOI: 10.1016/j.clinimag.2018.10.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/11/2018] [Accepted: 10/12/2018] [Indexed: 12/01/2022]
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Ludes C, Labani A, Severac F, Jeung MY, Leyendecker P, Roy C, Ohana M. Ultra-low-dose unenhanced chest CT: Prospective comparison of high kV/low mA versus low kV/high mA protocols. Diagn Interv Imaging 2018; 100:85-93. [PMID: 30559037 DOI: 10.1016/j.diii.2018.11.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 11/14/2018] [Accepted: 11/19/2018] [Indexed: 12/11/2022]
Abstract
PURPOSE To qualitatively and quantitatively compare unenhanced ultra-low-dose chest computed tomography (ULD-CT) acquired at 80kVp and 135kVp. MATERIALS AND METHODS Fifty-one patients referred for unenhanced chest CT were prospectively included. There were 29 men and 22 women, with a mean age of 64.7±11.6 (SD) years (range: 35-91 years) and a mean body mass index of 26.2±6.3 (SD) (range: 17-54.9). All patients underwent two different ULD-CT protocols (80kVp-40mA and 135kVp-10mA). Image quality of both ULD-CT examinations using a 5-level scale as well as assessability of 6 predetermined lung parenchyma lesions were blindly evaluated by three radiologists and compared using a logistic regression model. Image noise of the two protocols was compared with Wilcoxon signed-rank test. RESULTS The mean dose-length product at 80kVp and at 135kVp were 14.7±1.8 (SD) mGy.cm and 15.6±1.9 (SD) mGy.cm, respectively (P<0.001). Image noise was significantly lower at 135kVp (58.9±12.4) than at 80kVp (74.7±14.5) (P<0.001). For all readers and for all examinations, the 135kVp protocol yielded better image quality than 80kVp protocol, with a mean qualitative score of 4.5±0.7 versus 3.9±0.8 (P<0.001). The 135kVp protocol was significantly more often of diagnostic quality than the 80kvp protocol (92.3% versus 77.8%, respectively) (P<0.001) and was less prone to image quality deterioration in obese patients. Parenchymal lesions were never better depicted on the 80kVp protocol than with the 135kVp protocol. CONCLUSION Unenhanced chest ULD-CT should be acquired at a high kilovoltage and low current, such as 135kVp-10mA, over a low kilovoltage and high current protocol.
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Affiliation(s)
- C Ludes
- Department of Radiology B, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France
| | - A Labani
- Department of Radiology B, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France
| | - F Severac
- Department of Public Health, Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France; iCube Laboratory, Université de Strasbourg, CNRS, UMR 7357, 67400 Illkirch, France
| | - M Y Jeung
- Department of Radiology B, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France
| | - P Leyendecker
- Department of Radiology B, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France
| | - C Roy
- Department of Radiology B, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France
| | - M Ohana
- Department of Radiology B, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France; iCube Laboratory, Université de Strasbourg, CNRS, UMR 7357, 67400 Illkirch, France.
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Paks M, Leong P, Einsiedel P, Irving LB, Steinfort DP, Pascoe DM. Ultralow dose CT for follow-up of solid pulmonary nodules: A pilot single-center study using Bland-Altman analysis. Medicine (Baltimore) 2018; 97:e12019. [PMID: 30142849 PMCID: PMC6112944 DOI: 10.1097/md.0000000000012019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Solid pulmonary nodules are a common finding requiring serial computed tomography (CT) imaging. We sought to explore the detection and measurement accuracy of an ultralow-dose CT (ULDCT) protocol compared with our standard low-dose CT (LDCT) nodule follow-up protocol.In this pragmatic single-center pilot prospective cohort study, patients scheduled for clinically indicated CT surveillance of 1 or more known solid pulmonary nodules >2 mm underwent ULDCT immediately after routine LDCT. The Bland-Altman 95% limits of agreement for diameter and volumetry were calculated.In all, 57 patients underwent 60 imaging episodes, with 170 evaluable nodules. ULDCT detected all known solid pulmonary nodules >2 mm. Bland-Altman analyses demonstrated clinically agreement for both nodule diameter and volume, both of which fell within prespecified limits.This single-center pilot study suggests that ULDCT may be of use in surveillance of known solid pulmonary nodules >2 mm.
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Affiliation(s)
| | - Paul Leong
- Department of Respiratory Medicine, Melbourne Health
| | | | - Louis B. Irving
- Department of Respiratory Medicine, Melbourne Health
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Daniel P. Steinfort
- Department of Respiratory Medicine, Melbourne Health
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Diane M. Pascoe
- Department of Radiology
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
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Yan C, Xu J, Liang C, Wei Q, Wu Y, Xiong W, Zheng H, Xu Y. Radiation Dose Reduction by Using CT with Iterative Model Reconstruction in Patients with Pulmonary Invasive Fungal Infection. Radiology 2018; 288:285-292. [DOI: 10.1148/radiol.2018172107] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chenggong Yan
- From the Department of Medical Imaging Center (C.Y., C.L., Y.W., W.X., H.Z., Y.X.) and Department of Hematology (J.X., Q.W.), Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou 510515, Guangdong, People’s Republic of China
| | - Jun Xu
- From the Department of Medical Imaging Center (C.Y., C.L., Y.W., W.X., H.Z., Y.X.) and Department of Hematology (J.X., Q.W.), Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou 510515, Guangdong, People’s Republic of China
| | - Chunyi Liang
- From the Department of Medical Imaging Center (C.Y., C.L., Y.W., W.X., H.Z., Y.X.) and Department of Hematology (J.X., Q.W.), Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou 510515, Guangdong, People’s Republic of China
| | - Qi Wei
- From the Department of Medical Imaging Center (C.Y., C.L., Y.W., W.X., H.Z., Y.X.) and Department of Hematology (J.X., Q.W.), Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou 510515, Guangdong, People’s Republic of China
| | - Yuankui Wu
- From the Department of Medical Imaging Center (C.Y., C.L., Y.W., W.X., H.Z., Y.X.) and Department of Hematology (J.X., Q.W.), Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou 510515, Guangdong, People’s Republic of China
| | - Wei Xiong
- From the Department of Medical Imaging Center (C.Y., C.L., Y.W., W.X., H.Z., Y.X.) and Department of Hematology (J.X., Q.W.), Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou 510515, Guangdong, People’s Republic of China
| | - Huan Zheng
- From the Department of Medical Imaging Center (C.Y., C.L., Y.W., W.X., H.Z., Y.X.) and Department of Hematology (J.X., Q.W.), Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou 510515, Guangdong, People’s Republic of China
| | - Yikai Xu
- From the Department of Medical Imaging Center (C.Y., C.L., Y.W., W.X., H.Z., Y.X.) and Department of Hematology (J.X., Q.W.), Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou 510515, Guangdong, People’s Republic of China
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Lee KH, Lee KW, Park JH, Han K, Kim J, Lee SM, Park CM. Nodule Classification on Low-Dose Unenhanced CT and Standard-Dose Enhanced CT: Inter-Protocol Agreement and Analysis of Interchangeability. Korean J Radiol 2018; 19:516-525. [PMID: 29713230 PMCID: PMC5904479 DOI: 10.3348/kjr.2018.19.3.516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 11/13/2017] [Indexed: 12/19/2022] Open
Abstract
Objective To measure inter-protocol agreement and analyze interchangeability on nodule classification between low-dose unenhanced CT and standard-dose enhanced CT. Materials and Methods From nodule libraries containing both low-dose unenhanced and standard-dose enhanced CT, 80 solid and 80 subsolid (40 part-solid, 40 non-solid) nodules of 135 patients were selected. Five thoracic radiologists categorized each nodule into solid, part-solid or non-solid. Inter-protocol agreement between low-dose unenhanced and standard-dose enhanced images was measured by pooling κ values for classification into two (solid, subsolid) and three (solid, part-solid, non-solid) categories. Interchangeability between low-dose unenhanced and standard-dose enhanced CT for the classification into two categories was assessed using a pre-defined equivalence limit of 8 percent. Results Inter-protocol agreement for the classification into two categories {κ, 0.96 (95% confidence interval [CI], 0.94-0.98)} and that into three categories (κ, 0.88 [95% CI, 0.85-0.92]) was considerably high. The probability of agreement between readers with standard-dose enhanced CT was 95.6% (95% CI, 94.5-96.6%), and that between low-dose unenhanced and standard-dose enhanced CT was 95.4% (95% CI, 94.7-96.0%). The difference between the two proportions was 0.25% (95% CI, -0.85-1.5%), wherein the upper bound CI was markedly below 8 percent. Conclusion Inter-protocol agreement for nodule classification was considerably high. Low-dose unenhanced CT can be used interchangeably with standard-dose enhanced CT for nodule classification.
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Affiliation(s)
- Kyung Hee Lee
- Department of Radiology, Seoul National University Bundang Hospital, Seongnam 13620, Korea
| | - Kyung Won Lee
- Department of Radiology, Seoul National University Bundang Hospital, Seongnam 13620, Korea
| | - Ji Hoon Park
- Department of Radiology, Seoul National University Bundang Hospital, Seongnam 13620, Korea
| | - Kyunghwa Han
- Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Jihang Kim
- Department of Radiology, Seoul National University Bundang Hospital, Seongnam 13620, Korea
| | - Sang Min Lee
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Chang Min Park
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea.,Cancer Research Institute, Seoul National University College of Medicine, Seoul 03080, Korea
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Lee KB, Goo HW. Quantitative Image Quality and Histogram-Based Evaluations of an Iterative Reconstruction Algorithm at Low-to-Ultralow Radiation Dose Levels: A Phantom Study in Chest CT. Korean J Radiol 2018; 19:119-129. [PMID: 29354008 PMCID: PMC5768492 DOI: 10.3348/kjr.2018.19.1.119] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/28/2017] [Indexed: 01/17/2023] Open
Abstract
Objective To describe the quantitative image quality and histogram-based evaluation of an iterative reconstruction (IR) algorithm in chest computed tomography (CT) scans at low-to-ultralow CT radiation dose levels. Materials and Methods In an adult anthropomorphic phantom, chest CT scans were performed with 128-section dual-source CT at 70, 80, 100, 120, and 140 kVp, and the reference (3.4 mGy in volume CT Dose Index [CTDIvol]), 30%-, 60%-, and 90%-reduced radiation dose levels (2.4, 1.4, and 0.3 mGy). The CT images were reconstructed by using filtered back projection (FBP) algorithms and IR algorithm with strengths 1, 3, and 5. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were statistically compared between different dose levels, tube voltages, and reconstruction algorithms. Moreover, histograms of subtraction images before and after standardization in x- and y-axes were visually compared. Results Compared with FBP images, IR images with strengths 1, 3, and 5 demonstrated image noise reduction up to 49.1%, SNR increase up to 100.7%, and CNR increase up to 67.3%. Noteworthy image quality degradations on IR images including a 184.9% increase in image noise, 63.0% decrease in SNR, and 51.3% decrease in CNR, and were shown between 60% and 90% reduced levels of radiation dose (p < 0.0001). Subtraction histograms between FBP and IR images showed progressively increased dispersion with increased IR strength and increased dose reduction. After standardization, the histograms appeared deviated and ragged between FBP images and IR images with strength 3 or 5, but almost normally-distributed between FBP images and IR images with strength 1. Conclusion The IR algorithm may be used to save radiation doses without substantial image quality degradation in chest CT scanning of the adult anthropomorphic phantom, down to approximately 1.4 mGy in CTDIvol (60% reduced dose).
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Affiliation(s)
- Ki Baek Lee
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Hyun Woo Goo
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
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Canellas R, Ackman JB, Digumarthy SR, Price M, Otrakji A, McDermott S, Sharma A, Kalra MK. Submillisievert chest dual energy computed tomography: a pilot study. Br J Radiol 2017; 91:20170735. [PMID: 29125334 DOI: 10.1259/bjr.20170735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE To assess if diagnostic dual energy CT (DECT) of the chest can be achieved at submillisievert (sub-mSv) doses. METHODS Our IRB-approved prospective study included 20 patients who were scanned on dual-source multidector CT(MDCT). All patients gave written informed consent for acquisition of additional image series at reduced radiation dose on a dual-source MDCT (80/140 kV) within 10 s after the standard of care acquisition. Dose reduction was achieved by reducing the quality reference milliampere-second, with combined angular exposure control. Four readers, blinded to all clinical data, evaluated the image sets. Image noise, signal-to-noise and contrast-to-noise ratio were assessed. Volumetric CT dose index (CTDIvol), doselength product (DLP), size specific dose estimate, and effective dose were also recorded. RESULTS The mean age and body mass index of the patients were 71 years ± 9 and 24 kg m-2 ± 3, respectively. Although images became noisier, overall image quality and image sharpness on blended images were considered good or excellent in all cases (20/20). All findings made on the reduced dose images presented with good demarcation. The intraobserver and interobserver agreements were κ = 0.83 and 0.73, respectively. Mean CTDIvol, size specific dose estimate, DLP and effective dose for reduced dose DECT were: 1.3 ± 0.2 mGy, 1.8 ± 0.2 mGy, 51 ± 9.9 mGy.cm and 0.7 ± 0.1 mSv, respectively. CONCLUSION Routine chest DECT can be performed at sub-mSv doses with good image quality and without loss of relevant diagnostic information. Advances in knowledge: (1) Contrast-enhanced DECT of the chest can be performed at sub-mSv doses, down to mean CTDIvol 1.3 mGy and DLP 51 mGy.cm in patients with body mass index <31 kg m-2. (2) To our knowledge, this is the first time that sub-mSv doses have been successfully applied in a patient study using a dual source DECT scanner.
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Affiliation(s)
- Rodrigo Canellas
- Division of Thoracic Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Jeanne B Ackman
- Division of Thoracic Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Subba R Digumarthy
- Division of Thoracic Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Melissa Price
- Division of Thoracic Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Alexi Otrakji
- Division of Thoracic Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Shaunagh McDermott
- Division of Thoracic Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Amita Sharma
- Division of Thoracic Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Mannudeep K Kalra
- Division of Thoracic Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
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Leutz-Schmidt P, Weinheimer O, Jobst BJ, Dinkel J, Biederer J, Kauczor HU, Puderbach MU, Wielpütz MO. Influence of exposure parameters and iterative reconstruction on automatic airway segmentation and analysis on MDCT-An ex vivo phantom study. PLoS One 2017; 12:e0182268. [PMID: 28767732 PMCID: PMC5540604 DOI: 10.1371/journal.pone.0182268] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 07/14/2017] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES To evaluate the influence of exposure parameters and raw-data-based iterative reconstruction (IR) on computer-aided segmentation and quantitative analysis of the tracheobronchial tree on multidetector computed tomography (MDCT). MATERIAL AND METHODS 10 porcine heart-lung-explants were mounted inside a dedicated chest phantom. MDCT was performed at 120kV and 80kV with 120, 60, 30 and 12 mAs each. All scans were reconstructed with filtered back projection (FBP) or IR, resulting in a total of 160 datasets. The maximum number of detected airway segments, most peripheral airway generation detected, generation-specific airway wall thickness (WT), total diameter (TD) and normalized wall thickness (pi10) were compared. RESULTS The number of detected airway segments decreased slightly with dose (324.8±118 at 120kV/120mAs vs. 288.9±130 at 80kV/30mAs with FBP, p<0.05) and was not changed by IR. The 20th generation was constantly detected as most peripheral. WT did not change significantly with exposure parameters and reconstruction algorithm across all generations: range 1st generation 2.4-2.7mm, 5th 1.0-1.1mm, and 10th 0.7mm with FBP; 1st 2.3-2.4mm, 5th 1.0-1.1mm, and 10th 0.7-0.8mm with IR. pi10 was not affected as well (range 0.32-0.34mm). CONCLUSIONS Exposure parameters and IR had no relevant influence on measured airway parameters even for WT <1mm. Thus, no systematic errors would be expected using automatic airway analysis with low-dose MDCT and IR.
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Affiliation(s)
- Patricia Leutz-Schmidt
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany
| | - Oliver Weinheimer
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany
| | - Bertram J. Jobst
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany
| | - Julien Dinkel
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany
| | - Jürgen Biederer
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
- Radiologie Darmstadt, Gross-Gerau County Hospital, Gross-Gerau, Germany
- Department of Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany
| | - Hans-Ulrich Kauczor
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany
| | - Michael U. Puderbach
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany
- Department of Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany
| | - Mark O. Wielpütz
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Heidelberg, Germany
- Department of Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany
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Nagatani Y, Takahashi M, Ikeda M, Yamashiro T, Koyama H, Koyama M, Moriya H, Noma S, Tomiyama N, Ohno Y, Murata K, Murayama S, Moriya H, Sakuma K, Koyama M, Honda O, Tomiyama N, Koyama H, Ohno Y, Sugimura K, Sakamoto R, Nishimoto Y, Noma S, Tada A, Kato K, Miyara T, Yamashiro T, Kamiya H, Kamiya A, Tanaka Y, Murayama S, Nagatani Y, Nitta N, Takahashi M, Murata K. Sub-solid Nodule Detection Performance on Reduced-dose Computed Tomography with Iterative Reduction: Comparison Between 20 mA (7 mAs) and 120 mA (42 mAs) Regarding Nodular Size and Characteristics and Association with Size-specific Dose Estimate. Acad Radiol 2017; 24:995-1007. [PMID: 28606593 DOI: 10.1016/j.acra.2017.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 12/17/2022]
Abstract
RATIONALE AND OBJECTIVES This study aimed to compare sub-solid nodule detection performances (SSNDP) on chest computed tomography (CT) with Adaptive Iterative Dose Reduction using Three Dimensional Processing (AIDR 3D) between 7 mAs (0.21 mSv) and 42 mAs (1.28 mSv) in total and in subgroups classified by nodular size, characteristics, and location, and analyze the association of SSNDP with size-specific dose estimate (SSDE). MATERIALS AND METHODS As part of the Area-detector Computed Tomography for the Investigation of Thoracic Diseases Study, a Japanese multicenter research project, 68 subjects underwent chest CT with 120 kV, 0.35 seconds per rotation, and three tube currents: 240 mA (84 mAs), 120 mA (42 mAs), and 20 mA (7 mAs). The research committee of the study project outlined and approved our study protocols. The institutional review board of each institution approved this study. Axial 2-mm-thick CT images were reconstructed using AIDR 3D. Standard reference was determined by CT images at 84 mAs. Four radiologists recorded SSN presence by continuously distributed rating on CT at 7 mAs and 42 mAs. Receiver operating characteristic analysis was used to evaluate SSNDP at both doses in total and in subgroups classified by nodular longest diameter (LD) (≥5 mm), characteristics (pure and part-solid), and locations (ventral, intermediate, or dorsal; central or peripheral; and upper, middle, or lower). Detection sensitivity was compared among five groups of SSNs classified based on particular SSDE to nodule on CT with AIDR 3D at 7 mAs. RESULTS Twenty-two part-solid and 86 pure SSNs were identified. For larger SSNs (LD ≥ 5 mm) as well as subgroups classified by nodular locations and part-solid nodules, SSNDP was similar in both methods (area under the receiver operating characteristics curve: 0.96 ± 0.02 in CT at 7 mAs and 0.97 ± 0.01 in CT at 42 mAs), with acceptable interobserver agreements in five locations. For larger SSNs (LD ≥ 5 mm), on CT at 42 mAs, no significant differences in detection sensitivity were found among the five groups classified by SSDE, whereas on CT with 7 mAs, four groups with SSDE of 0.65 or higher were superior in detection sensitivity to the other group, with SSDE less than 0.65 mGy. CONCLUSIONS For SSNs with 5 mm or more in cases with normal range of body habitus, CT at 7 mAs was demonstrated to have comparable SSNDP to CT at 42 mAs regardless of nodular location and characteristics, and SSDE higher than 0.65 mGy is desirable to obtain sufficient SSNDP.
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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] [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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Silveira de Souza VV, Soares Torres F, Hochhegger B, Watte G, Sartori G, Lucchese F, Azambuja Gonçalves B. Performance of ultra-low-dose CT for the evaluation of coronary calcification: a direct comparison with coronary calcium score. Clin Radiol 2017; 72:745-750. [PMID: 28413071 DOI: 10.1016/j.crad.2017.03.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/15/2017] [Accepted: 03/20/2017] [Indexed: 12/20/2022]
Abstract
AIM To evaluate the diagnostic performance of ultra-low-dose computed tomography (ULDCT) in comparison to standard coronary calcium score (CCS) acquisition for the evaluation of coronary artery calcification (CAC). MATERIALS AND METHODS Standard CCS acquisition and ULDCT were performed in patients referred for coronary CT angiography for the evaluation of coronary artery disease. CAC in ULDCT was graded subjectively using a four-point scale (from 0, no calcification, to 3, severe calcification) for the complete study and for each individual coronary segment. The summation of all individual coronary segment scores generated an ULDCT total CAC score. ULDCT results were compared to standard Agatston score and sensitivity and specificity of ULDCT were calculated. RESULTS CCS and ULDCT were performed in 74 patients, with a mean DLP of 77.7 mGy·cm (±12.1) and 9.3 mGy·cm (±0.6), respectively (p<0.001). Coronary calcification was detected in 47 patients (63.5%) in standard CCS acquisition (median Agatston score of 41; interquartile range [IQR]:0263), in comparison to 42 patients (56.8%) in ULDCT (p<0.001). The sensitivity and specificity of the ULDCT total CAC score ≥1 was 80.9% and 85.2%, respectively, with an accuracy of 82.4%. The area under the receiver operating characteristic curve for the presence of CAC was 0.87. CONCLUSION ULDCT shows good sensitivity, specificity, and overall accuracy for the detection of coronary calcification with a markedly lower radiation dose in comparison to CCS. ULDCT is unlikely to miss coronary calcification in individuals with at least moderate calcium load (Agatston score >100).
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Affiliation(s)
- V V Silveira de Souza
- Santa Casa de Misericórdia de Porto Alegre, Annes Dias St 295, Porto Alegre, Rio Grande do Sul, 90020-090, Brazil.
| | - F Soares Torres
- Santa Casa de Misericórdia de Porto Alegre, Annes Dias St 295, Porto Alegre, Rio Grande do Sul, 90020-090, Brazil
| | - B Hochhegger
- Santa Casa de Misericórdia de Porto Alegre, Annes Dias St 295, Porto Alegre, Rio Grande do Sul, 90020-090, Brazil
| | - G Watte
- Santa Casa de Misericórdia de Porto Alegre, Annes Dias St 295, Porto Alegre, Rio Grande do Sul, 90020-090, Brazil
| | - G Sartori
- Santa Casa de Misericórdia de Porto Alegre, Annes Dias St 295, Porto Alegre, Rio Grande do Sul, 90020-090, Brazil
| | - F Lucchese
- Santa Casa de Misericórdia de Porto Alegre, Annes Dias St 295, Porto Alegre, Rio Grande do Sul, 90020-090, Brazil
| | - B Azambuja Gonçalves
- Santa Casa de Misericórdia de Porto Alegre, Annes Dias St 295, Porto Alegre, Rio Grande do Sul, 90020-090, Brazil
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Sui X, Du Q, Xu KF, Tian X, Song L, Wang X, Xu X, Wang Z, Wang Y, Gu J, Song W, Jin Z. Quantitative assessment of Pulmonary Alveolar Proteinosis (PAP) with ultra-dose CT and correlation with Pulmonary Function Tests (PFTs). PLoS One 2017; 12:e0172958. [PMID: 28301535 PMCID: PMC5354367 DOI: 10.1371/journal.pone.0172958] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/13/2017] [Indexed: 12/14/2022] Open
Abstract
Background The purpose of this study was to investigate whether ultra-low-dose chest computed tomography (CT) can be used for visual assessment of CT features in patients with pulmonary alveolar proteinosis (PAP) and to evaluate the relationship between the quantitative analysis of the ultra-low-dose CT scans and the pulmonary function tests (PFTs). Methods Thirty-eight patients (mean [SD] age, 44.47 [12.28] years; 29 males, 9 females) with PAP were enrolled and subjected to two scans each with low-dose CT (reference parameters: 120 kV and 50 mAs) and ultra-low-dose CT (reference parameters, 80 kV, 25 mAs). Images were reconstructed via filtered back projection (FBP) for low-dose CT and iterative reconstruction (IR) for ultra-low-dose CT. All patients underwent PFT. The Visual analysis for ground glass opacity (GGO) is performed. The quantitative CT and PFT results were analyzed by canonical correlations. Results The mean body mass index (BMI) was 25.37±3.26 kg/m2. The effective radiation doses were 2.30±0.46 and 0.24±0.05 mSv for low-dose and ultra-low-dose CT, respectively. The size-specific dose estimates were 5.81±0.81 and 0.62±0.09 mSv for low-dose and ultra-low-dose CT. GGOs and interlobular septal thickening were observed bilaterally in all patients. The average visual GGO score was lower in the upper field (2.67±1.24) but higher in the middle and lower fields (3.08±1.32 and 3.08±0.97, respectively). The average score for the whole lung was 2.94±1.19. There is a significant correlation between PFTs and quantitative of ultra-low-dose CT (canonical loading = 0.78). Conclusions Ultra-low-dose CT has the potential to quantify the lung parenchyma changes of PAP. This technique could provide a sensitive and objective assessment of PAP and has good relation with PFTs. In addition, the radiation dose of ultra-low-dose CT was very low.
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Affiliation(s)
- Xin Sui
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Qianni Du
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Kai-feng Xu
- Department of Respiratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xinlun Tian
- Department of Respiratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Lan Song
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiao Wang
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaoli Xu
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Zixing Wang
- Department of Epidemiology and Biostatistics, Institute of Basic Medical Science, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Yuyan Wang
- Department of Epidemiology and Biostatistics, Institute of Basic Medical Science, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Jun Gu
- Siemens Healthineers, Beijing, China
| | - Wei Song
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- * E-mail:
| | - Zhengyu Jin
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
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Chen Y, Liu J, Hu Y, Yang J, Shi L, Shu H, Gui Z, Coatrieux G, Luo L. Discriminative feature representation: an effective postprocessing solution to low dose CT imaging. Phys Med Biol 2017; 62:2103-2131. [PMID: 28212114 DOI: 10.1088/1361-6560/aa5c24] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This paper proposes a concise and effective approach termed discriminative feature representation (DFR) for low dose computerized tomography (LDCT) image processing, which is currently a challenging problem in medical imaging field. This DFR method assumes LDCT images as the superposition of desirable high dose CT (HDCT) 3D features and undesirable noise-artifact 3D features (the combined term of noise and artifact features induced by low dose scan protocols), and the decomposed HDCT features are used to provide the processed LDCT images with higher quality. The target HDCT features are solved via the DFR algorithm using a featured dictionary composed by atoms representing HDCT features and noise-artifact features. In this study, the featured dictionary is efficiently built using physical phantom images collected from the same CT scanner as the target clinical LDCT images to process. The proposed DFR method also has good robustness in parameter setting for different CT scanner types. This DFR method can be directly applied to process DICOM formatted LDCT images, and has good applicability to current CT systems. Comparative experiments with abdomen LDCT data validate the good performance of the proposed approach.
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Affiliation(s)
- Yang Chen
- Laboratory of Image Science and Technology, Southeast University, Nanjing 210096, People's Republic of China. Centre de Recherche en Information Biomedicale Sino-Francais (LIA CRIBs), Rennes, France. Key Laboratory of Computer Network and Information Integration (Southeast University), Ministry of Education, People's Republic of China
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Fujita M, Higaki T, Awaya Y, Nakanishi T, Nakamura Y, Tatsugami F, Baba Y, Iida M, Awai K. Lung cancer screening with ultra-low dose CT using full iterative reconstruction. Jpn J Radiol 2017; 35:179-189. [PMID: 28197820 DOI: 10.1007/s11604-017-0618-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 01/31/2017] [Indexed: 12/18/2022]
Abstract
PURPOSE To investigate the diagnostic capability of ultra-low-dose CT (ULDCT) with full iterative reconstruction (f-IR) for lung cancer screening. MATERIALS AND METHODS All underwent ULDCT and/or low-dose CT (LD-CT) on a 320-detector scanner. ULDCT images were reconstructed with f-IR. We qualitatively and quantitatively studied 95 nodules in 69 subjects. Two radiologists classified the nodules on ULDCT images as solid-, part-solid-, and pure ground-glass (PGG) and recorded their mean size. Their findings were compared with the reference standard. The observer performance study included 7 other radiologists and 35 subjects with- and 15 without nodules. The results were analyzed by AFROC analysis. RESULTS In the qualitative study, the kappa values between observers 1 and 2, respectively, and the reference standard were 0.70 and 0.83; the intra-class correlation coefficients for the nodule diameter between the reference standard and their measurements were 0.84 and 0.90. The 95% confidence interval (CI) for the area under the curve (AUC) difference for nodule detection on LDCT and ULDCT was -0.03 to 0.07. The 95% CI crossed the 0 difference in the AUC but not the pre-defined non-inferiority margin of -0.08. CONCLUSION The diagnostic ability of ULDCT using f-IR is comparable to LDCT.
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Affiliation(s)
- Masayo Fujita
- Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan
| | - Toru Higaki
- Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan
| | - Yoshikazu Awaya
- Department of Internal Medicine, Miyoshi Central Hospital, 531 Sakaya-cho, Miyoshi, Hiroshima, 728-0023, Japan
| | - Toshio Nakanishi
- Department of Internal Medicine, Miyoshi Central Hospital, 531 Sakaya-cho, Miyoshi, Hiroshima, 728-0023, Japan
| | - Yuko Nakamura
- Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan
| | - Fuminari Tatsugami
- Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan
| | - Yasutaka Baba
- Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan
| | - Makoto Iida
- Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan.
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Bodelle B, Fischbach C, Booz C, Yel I, Frellesen C, Beeres M, Vogl TJ, Scholtz JE. Free-breathing high-pitch 80kVp dual-source computed tomography of the pediatric chest: Image quality, presence of motion artifacts and radiation dose. Eur J Radiol 2017; 89:208-214. [PMID: 28267541 DOI: 10.1016/j.ejrad.2017.01.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/18/2017] [Accepted: 01/26/2017] [Indexed: 01/11/2023]
Abstract
OBJECTIVES To investigate image quality, presence of motion artifacts and effects on radiation dose of 80kVp high-pitch dual-source CT (DSCT) in combination with an advanced modeled iterative reconstruction algorithm (ADMIRE) of the pediatric chest compared to single-source CT (SSCT). MATERIALS AND METHODS The study was approved by the institutional review board. Eighty-seven consecutive pediatric patients (mean age 9.1±4.9years) received either free-breathing high-pitch (pitch 3.2) chest 192-slice DSCT (group 1, n=31) or standard-pitch (pitch 1.2) 128-slice SSCT (group 2, n=56) with breathing-instructions by random assignment. Tube settings were similar in both groups with 80 kVp and 74 ref. mAs. Images were reconstructed using FBP for both groups. Additionally, ADMIRE was used in group 1. Effective thorax diameter, image noise, and signal-to-noise ratio (SNR) of the pectoralis major muscle and the thoracic aorta were calculated. Motion artifacts were measured as doubling boarders of the diaphragm and the heart. Images were rated by two blinded readers for overall image quality and presence of motion artifacts on 5-point-scales. Size specific dose estimates (SSDE, mGy) and effective dose (ED, mSv) were calculated. RESULTS Age and effective thorax diameter showed no statistically significant differences in both groups. Image noise and SNR were comparable (p>0.64) for SSCT and DSCT with ADMIRE, while DSCT with FBP showed inferior results (p<0.01). Motion artifacts were reduced significantly (p=0.001) with DSCT. DSCT with ADMIRE showed the highest overall IQ (p<0.0001). Radiation dose was lower for DSCT compared to SSCT (median SSDE: 0.82mGy vs. 0.92mGy, p<0.02; median ED: 0.4 mSv vs. 0.48mSv, p=0.02). CONCLUSIONS High-pitch 80kVp chest DSCT in combination with ADMIRE reduces motion artifacts and increases image quality while lowering radiation exposure in free-breathing pediatric patients without sedation.
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Affiliation(s)
- Boris Bodelle
- Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
| | - Constanze Fischbach
- Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - Christian Booz
- Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - Ibrahim Yel
- Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - Claudia Frellesen
- Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - Martin Beeres
- Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - Thomas J Vogl
- Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - Jan-Erik Scholtz
- Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
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Ohana M, Ludes C, Schaal M, Meyer E, Jeung MY, Labani A, Roy C. [What future for chest x-ray against ultra-low-dose computed tomography?]. REVUE DE PNEUMOLOGIE CLINIQUE 2017; 73:3-12. [PMID: 27956084 DOI: 10.1016/j.pneumo.2016.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 09/19/2016] [Accepted: 09/24/2016] [Indexed: 06/06/2023]
Abstract
Technological improvements, with iterative reconstruction at the foreground, have lowered the radiation dose of a chest CT close to that of a PA and lateral chest x-ray. This ultra-low dose chest CT (ULD-CT) has an image quality that is degraded on purpose, yet remains diagnostic in many clinical indications. Thus, its effectiveness is already validated for the detection and the monitoring of solid parenchymal nodules, for the diagnosis and monitoring of infectious lung diseases and for the screening of pleural lesions secondary to asbestos exposure. Its limitations are the analysis of the mediastinal structures, the severe obesity (BMI>35) and the detection of interstitial lesions. If it can replace the standard chest CT in these indications, all the more in situations where radiation dose is a major problem (young patients, repeated exams, screening), it progressively emerges as a first line alternative for chest radiograph, providing more data at a similar radiation cost.
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Affiliation(s)
- M Ohana
- Service de radiologie, nouvel hôpital civil, hôpitaux universitaires de Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France; Laboratoire iCube, UMR 7357, CNRS, université de Strasbourg, 67400 Illkirch, France.
| | - C Ludes
- Service de radiologie, nouvel hôpital civil, hôpitaux universitaires de Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - M Schaal
- Service de radiologie, centre hospitalier de Haguenau, 64, avenue du Professeur-Leriche, 67500 Haguenau, France
| | - E Meyer
- Service de radiologie, nouvel hôpital civil, hôpitaux universitaires de Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - M-Y Jeung
- Service de radiologie, nouvel hôpital civil, hôpitaux universitaires de Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - A Labani
- Service de radiologie, nouvel hôpital civil, hôpitaux universitaires de Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - C Roy
- Service de radiologie, nouvel hôpital civil, hôpitaux universitaires de Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
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Diagnostic Performance of Ultra-Low-Dose Computed Tomography for Detecting Asbestos-Related Pleuropulmonary Diseases: Prospective Study in a Screening Setting. PLoS One 2016; 11:e0168979. [PMID: 28033378 PMCID: PMC5199059 DOI: 10.1371/journal.pone.0168979] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 12/11/2016] [Indexed: 12/21/2022] Open
Abstract
Objective To evaluate the diagnostic performance of Ultra-Low-Dose Chest CT (ULD CT) for the detection of any asbestos-related lesions (primary endpoint) and specific asbestos-related abnormalities, i.e. non-calcified and calcified pleural plaques, diffuse pleural thickening, asbestosis and significant lung nodules (secondary endpoints). Material and Methods 55 male patients (55.7±8.1 years old) with occupational asbestos exposure for at least 15 years and where CT screening was indicated were prospectively included. They all underwent a standard unenhanced chest CT (120kV, automated tube current modulation), considered as the reference, and an ULD CT (135kV, 10mA), both with iterative reconstruction. Two chest radiologists independently and blindly read the examinations, following a detailed protocol. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy and error rate of ULD CT were calculated using the exact method of Pearson with a confidence interval of 95%. Results Radiation dose was 17.9±1.2mGy.cm (0.25mSv) for the ULD-CT versus 288.8 ±151mGy.cm (4mSv); p <2.2e-16. Prevalence of abnormalities was 20%. The ULD CT’s diagnostic performance in joint reading was high for the primary endpoint (sensitivity = 90.9%, specificity = 100%, positive predictive value = 100%, negative predictive value = 97.8%), high for lung nodules, diffuse pleural thickening and calcified pleural plaques (sensitivity, specificity, PPV and NPV = 100%) and fair for asbestosis (sensitivity = 75%, specificity = 100%, PPV = 00%, NPV = 98.1%). Intra-reader accuracy between the ULD CT and the reference CT for the primary endpoint was 98% for the senior and 100% for the junior radiologist. Inter-reader agreement for the primary endpoint was almost perfect (Cohen’s Kappa of 0.81). Conclusion ULD CT in the screening of asbestos exposure related diseases has 90.9% sensitivity and 100% specificity, and could therefore be proposed as a first line examination.
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de Margerie-Mellon C, de Bazelaire C, Montlahuc C, Lambert J, Martineau A, Coulon P, de Kerviler E, Beigelman C. Reducing Radiation Dose at Chest CT: Comparison Among Model-based Type Iterative Reconstruction, Hybrid Iterative Reconstruction, and Filtered Back Projection. Acad Radiol 2016; 23:1246-54. [PMID: 27346234 DOI: 10.1016/j.acra.2016.05.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 05/30/2016] [Accepted: 05/31/2016] [Indexed: 12/15/2022]
Abstract
RATIONALE AND OBJECTIVES The study aimed to evaluate the performances of two iterative reconstruction (IR) algorithms and of filtered back projection (FBP) when using reduced-dose chest computed tomography (RDCT) compared to standard-of-care CT. MATERIALS AND METHODS An institutional review board approval was obtained. Thirty-six patients with hematologic malignancies referred for a control chest CT of a known lung disease were prospectively enrolled. Patients underwent standard-of-care scan reconstructed with hybrid IR, followed by an RDCT reconstructed with FBP, hybrid IR, and iterative model reconstruction. Objective and subjective quality measurements, lesion detectability, and evolution assessment on RDCT were recorded. RESULTS For RDCT, the CTDIvol (volumetric computed tomography dose index) was 0.43 mGy⋅cm for all patients, and the median [interquartile range] effective dose was 0.22 mSv [0.22-0.24]; corresponding measurements for standard-of-care scan were 3.4 mGy [3.1-3.9] and 1.8 mSv [1.6-2.0]. Noise significantly decreased from FBP to hybrid IR and from hybrid IR to iterative model reconstruction on RDCT, whereas lesion conspicuity and diagnostic confidence increased. Accurate evolution assessment was obtained in all cases with IR. Emphysema identification was higher with iterative model reconstruction. CONCLUSION Although iterative model reconstruction offered better diagnostic confidence and emphysema detection, both IR algorithms allowed an accurate evolution assessment with an effective dose of 0.22 mSv.
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Macri F, Greffier J, Pereira F, Rosa AC, Khasanova E, Claret PG, Larbi A, Gualdi G, Beregi JP. Value of ultra-low-dose chest CT with iterative reconstruction for selected emergency room patients with acute dyspnea. Eur J Radiol 2016; 85:1637-44. [DOI: 10.1016/j.ejrad.2016.06.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/13/2016] [Accepted: 06/30/2016] [Indexed: 12/18/2022]
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DNA damage in lymphocytes induced by cardiac CT and comparison with physical exposure parameters. Eur Radiol 2016; 27:1660-1666. [PMID: 27510626 DOI: 10.1007/s00330-016-4519-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 07/13/2016] [Accepted: 07/19/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVES To investigate whether physical exposure parameters such as the dose index (CTDI), dose length product (DLP), and size-specific dose estimate (SSDE) are predictive of DNA damage. METHODS In vitro, we scanned a phantom containing blood samples from five volunteers at CTDI 50, 100, and 150 mGy. One sample was not scanned. We also scanned samples in three different-size phantoms at CTDI 100 mGy. In vivo, we enrolled 45 patients and obtained blood samples before and after cardiac CT. The γ-H2AX foci were counted. RESULTS In vitro, in the control and at CTDI 50, 100, and 150 mGy, the number of γ-H2AX was 0.94 ± 0.24 (standard error, SE), 1.28 ± 0.30, 1.91 ± 0.47, and 2.16 ± 0.20. At SSDE 180, 156, and 135 mGy, it was 2.41 ± 0.20, 1.91 ± 0.47, and 1.42 ± 0.20 foci/cell. The γ-H2AX foci were positively correlated with the radiation dose and negatively correlated with the body size. In vivo, the γ-H2AX foci were significantly increased after CT (from 1.21 ± 0.19 to 1.92 ± 0.22 foci/cell) and correlated with CTDI, DLP, and SSDE. CONCLUSIONS DNA damage was induced by cardiac CT. There was a correlation between the physical exposure parameters and γ-H2AX. KEY POINTS • DNA damage was induced by radiation exposure from cardiac CT. • The γ-H2AX foci number was correlated with the CT radiation dose. • Physical exposure parameters reflect the DNA damage by CT radiation exposure.
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Ultra-low-dose chest CT with iterative reconstruction does not alter anatomical image quality. Diagn Interv Imaging 2016; 97:1131-1140. [PMID: 27451261 DOI: 10.1016/j.diii.2016.06.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 06/20/2016] [Accepted: 06/27/2016] [Indexed: 12/16/2022]
Abstract
PURPOSE To evaluate the effect of dose reduction with iterative reconstruction (IR) on image quality of chest CT scan. MATERIALS AND METHODS Eighteen human cadavers had chest CT with one reference CT protocol (RP-CT; 120kVp/200mAs) and two protocols with dose reduction: low-dose-CT (LD-CT; 120kVp/40mAs) and ultra-low-dose CT (ULD-CT; 120kVp/10mAs). Data were reconstructed with filter-back-projection (FBP) for RP-CT and with FBP and IR (sinogram affirmed iterative reconstruction [SAFIRE®]) algorithm for LD-CT and ULD-CT. Volume CT dose index (CTDIvol) were recorded. The signal-to-noise (SNR), contrast-to-noise (CNR) ratios of LD-CT and ULD-CT and quantitative parameters were compared to RP-CT. Two radiologists reviewed the CT examinations assessed independently the quality of anatomical structures and expressed a confidence level using a 2-point scale (50% and 95%). RESULTS CTDIvol was 2.69 mGy for LD-CT (-80%; P<0.01) and 0.67 mGy for ULD-CT (-95%; P<0.01) as compared to 13.42 mGy for RP-CT. SNR and CNR were significantly decreased (P<0.01) for LD-CT and ULD-CT, but IR improved these values satisfactorily. No significant differences were observed for quantitative measurements. Radiologists rated excellent/good the RP-CT and LD-CT images, whereas good/fair the ULD-CT images. Confidence level for subjective anatomical analysis was 95% for all protocols. CONCLUSIONS Dose reduction with a dose lower than 1 mGy, used in conjunction with IR allows performing chest CT examinations that provide a high quality of anatomical structures.
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Fursevich DM, LiMarzi GM, O'Dell MC, Hernandez MA, Sensakovic WF. Bariatric CT Imaging: Challenges and Solutions. Radiographics 2016; 36:1076-86. [PMID: 27232505 DOI: 10.1148/rg.2016150198] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The obesity epidemic in the adult and pediatric populations affects all aspects of health care, including diagnostic imaging. With the increasing prevalence of obese and morbidly obese patients, bariatric computed tomographic (CT) imaging is becoming common in day-to-day radiology practice, and a basic understanding of the unique problems that bariatric patients pose to the imaging community is crucial in any setting. Because larger patients may not fit into conventional scanners, having a CT scanner with an adequate table load limit, a large gantry aperture, a large scan field of view, and a high-power generator is a prerequisite for bariatric imaging. Iterative reconstruction methods, high tube current, and high tube voltage can reduce the image noise that is frequently seen in bariatric CT images. Truncation artifacts, cropping artifacts, and ring artifacts frequently complicate the interpretation of CT images of larger patients. If recognized, these artifacts can be easily reduced by using the proper CT equipment, scan acquisition parameters, and postprocessing options. Lastly, because of complex contrast material dynamics, contrast material-enhanced studies of bariatric patients require special attention. Understanding how the rate of injection, the scan timing, and the total mass of iodine affect vascular and parenchymal enhancement will help to optimize contrast-enhanced studies in the bariatric population. This article familiarizes the reader with the challenges that are frequently encountered at CT imaging of bariatric patients, beginning with equipment selection and ending with a review of the most commonly encountered obesity-related artifacts and the technical considerations in the acquisition of contrast-enhanced images. (©)RSNA, 2016.
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Affiliation(s)
- Dzmitry M Fursevich
- From the Department of Diagnostic Radiology, Florida Hospital, 601 E Rollins St, Orlando, FL 32803
| | - Gary M LiMarzi
- From the Department of Diagnostic Radiology, Florida Hospital, 601 E Rollins St, Orlando, FL 32803
| | - Matthew C O'Dell
- From the Department of Diagnostic Radiology, Florida Hospital, 601 E Rollins St, Orlando, FL 32803
| | - Manuel A Hernandez
- From the Department of Diagnostic Radiology, Florida Hospital, 601 E Rollins St, Orlando, FL 32803
| | - William F Sensakovic
- From the Department of Diagnostic Radiology, Florida Hospital, 601 E Rollins St, Orlando, FL 32803
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A Practice Quality Improvement Project: Reducing Dose of Routine Chest CT Imaging in a Busy Clinical Practice. J Digit Imaging 2016; 29:622-6. [PMID: 26992381 DOI: 10.1007/s10278-016-9877-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The purpose of this report is to describe our experience with the implementation of a practice quality improvement (PQI) project in thoracic imaging as part of the American Board of Radiology Maintenance of Certification process. The goal of this PQI project was to reduce the effective radiation dose of routine chest CT imaging in a busy clinical practice by employing the iDose(4) (Philips Healthcare) iterative reconstruction technique. The dose reduction strategy was implemented in a stepwise process on a single 64-slice CT scanner with a volume of 1141 chest CT scans during the year. In the first annual quarter, a baseline effective dose was established using the standard filtered back projection (FBP) algorithm protocol and standard parameters such as kVp and mAs. The iDose(4) technique was then applied in the second and third annual quarters while keeping all other parameters unchanged. In the fourth quarter, a reduction in kVp was also implemented. Throughout the process, the images were continually evaluated to assure that the image quality was comparable to the standard protocol from multiple other scanners. Utilizing a stepwise approach, the effective radiation dose was reduced by 23.62 and 43.63 % in quarters two and four, respectively, compared to our initial standard protocol with no perceived difference in diagnostic quality. This practice quality improvement project demonstrated a significant reduction in the effective radiation dose of thoracic CT scans in a busy clinical practice.
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Sui X, Meinel FG, Song W, Xu X, Wang Z, Wang Y, Jin Z, Chen J, Vliegenthart R, Schoepf UJ. Detection and size measurements of pulmonary nodules in ultra-low-dose CT with iterative reconstruction compared to low dose CT. Eur J Radiol 2016; 85:564-70. [PMID: 26860668 DOI: 10.1016/j.ejrad.2015.12.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 12/12/2015] [Accepted: 12/16/2015] [Indexed: 11/15/2022]
Affiliation(s)
- Xin Sui
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
| | - Felix G Meinel
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA; Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany.
| | - Wei Song
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaoli Xu
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
| | - Zixing Wang
- Department of Epidemiology and Biostatistics, Institute of Basic Medical Science, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, China.
| | - Yuyan Wang
- Department of Epidemiology and Biostatistics, Institute of Basic Medical Science, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, China.
| | - Zhengyu Jin
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
| | | | - Rozemarijn Vliegenthart
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA; University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Department of Radiology, Groningen, The Netherlands.
| | - U Joseph Schoepf
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.
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Lim HK, Ha HI, Hwang HJ, Lee K. Feasibility of high-pitch dual-source low-dose chest CT: Reduction of radiation and cardiac artifacts. Diagn Interv Imaging 2016; 97:443-9. [PMID: 26896374 DOI: 10.1016/j.diii.2016.01.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 01/07/2016] [Accepted: 01/07/2016] [Indexed: 11/17/2022]
Abstract
PURPOSE To compare the radiation dose and image quality, focused mainly on cardiac pulsation artifact, between high-pitch low-dose chest computed tomography (HP-LDCT) and standard low-dose chest CT (LDCT). PATIENTS AND METHODS One hundred patients underwent HP-LDCT (50 patients) or LDCT (50 patients). Scan parameters were the same except for the pitch and gantry rotation time: 3.0 vs. 1.2 and 0.28s vs. 0.5s, respectively. Objective image noise at five regions and subjective image quality, such as noise, artifacts, cardiac pulsation artifacts, and overall diagnostic acceptability, were evaluated using a five-point scale. The significance level for all tests was set at P<0.05. RESULTS The dose-length products (DLPs) with HP-LDCT and LDCT were 90.2±4.3mGycm and 103.1±6.4mGycm, respectively (P<0.01). DLP of HP-LDCT showed a 13% reduction versus LDCT. Objective image noise was not significantly different. Cardiac pulsation artifacts showed a significant reduction on HP-LDCT (P<0.01). Other subjective image quality parameters of HP-LDCT were similar to those of LDCT. The overall diagnostic acceptability of HP-LDCT was better than that of LDCT (P<0.01). CONCLUSIONS HP-LDCT showed a 13% mean radiation dose reduction with no deterioration in image quality due to cardiac pulsation artifacts.
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Affiliation(s)
- H K Lim
- Department of Radiology, Soonchunhyang University Seoul Hospital, 59 Daesagwan-ro, Yongsan-gu, Seoul, 140-743, Republic of Korea.
| | - H I Ha
- Department of Radiology, Hallym University Medical Center, Hallym University Sacred Heart Hospital, 896 Pyeongchon-dong, Dongan-gu, Anyang-si, Gyeonggi-do, 431-070, Republic of Korea.
| | - H J Hwang
- Department of Radiology, Hallym University Medical Center, Hallym University Sacred Heart Hospital, 896 Pyeongchon-dong, Dongan-gu, Anyang-si, Gyeonggi-do, 431-070, Republic of Korea.
| | - K Lee
- Department of Radiology, Hallym University Medical Center, Hallym University Sacred Heart Hospital, 896 Pyeongchon-dong, Dongan-gu, Anyang-si, Gyeonggi-do, 431-070, Republic of Korea.
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Ludes C, Schaal M, Labani A, Jeung MY, Roy C, Ohana M. [Ultra-low dose chest CT: The end of chest radiograph?]. Presse Med 2016; 45:291-301. [PMID: 26830922 DOI: 10.1016/j.lpm.2015.12.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/27/2015] [Accepted: 12/08/2015] [Indexed: 12/17/2022] Open
Abstract
Ultra-low dose chest CT (ULD-CT) is acquired at a radiation dose lowered to that of a PA and lateral chest X-ray. Its image quality is degraded, yet remains diagnostic in many clinical indications. Technological improvements, with iterative reconstruction at the foreground, allowed a strong increase in the image quality obtained with this examination, which is achievable on most recent (<5 years) scanner. Established clinical indications of ULD-CT are increasing, and its non-inferiority compared to the reference "full dose" chest CT are currently demonstrated for the detection of solid nodules, for asbestos-related pleural diseases screening and for the monitoring of infectious pneumonia. Its current limitations are the obese patients (BMI>35) and the interstitial pneumonia, situations in which their performances are insufficient.
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Affiliation(s)
- Claire Ludes
- Hôpitaux universitaires de Strasbourg, Nouvel hôpital civil, service de radiologie, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - Marysa Schaal
- Centre hospitalier de Haguenau, service de radiologie, 64, avenue du Professeur-Leriche, 67500 Haguenau, France
| | - Aissam Labani
- Hôpitaux universitaires de Strasbourg, Nouvel hôpital civil, service de radiologie, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - Mi-Young Jeung
- Hôpitaux universitaires de Strasbourg, Nouvel hôpital civil, service de radiologie, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - Catherine Roy
- Hôpitaux universitaires de Strasbourg, Nouvel hôpital civil, service de radiologie, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - Mickaël Ohana
- Hôpitaux universitaires de Strasbourg, Nouvel hôpital civil, service de radiologie, 1, place de l'Hôpital, 67000 Strasbourg, France; Université de Strasbourg/CNRS, laboratoire iCube, UMR 7357, 67400 Illkirch, France.
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Iterative Reconstruction Leads to Increased Subjective and Objective Image Quality in Cranial CT in Patients With Stroke. AJR Am J Roentgenol 2015; 205:618-22. [PMID: 26295650 DOI: 10.2214/ajr.15.14389] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE The purpose of this study was to determine whether iterative reconstruction improves the quality of cranial CT (CCT) images of stroke patients. MATERIALS AND METHODS Fifty-one CCT studies of patients with infarction performed with either a low (260 mAs; n = 21) or standard (340 mAs; n = 30) dose were reconstructed with both filtered back projection (FBP) and sinogram-affirmed iterative reconstruction (SAFIRE) with five strength levels (S1-S5). The resulting six image sets (one FBP and one each for SAFIRE levels S1-S5) were rated separately by two blinded radiologists in terms of conspicuity of infarcted areas on a 5-point scale. Noise and infarct-to-normal brain as well as medullary-to-cortical contrast-to-noise ratios (CNRs) were measured. Ratings, noise, and CNRs were intraindividually compared within the same dose group (Fisher exact test) and interindividually between the different dose groups (Wilcoxon-Mann-Whitney U test). RESULTS The strength level S4 showed the best conspicuity of infarcted areas. Compared with FBP, SAFIRE S4 statistically significantly (p < 0.01) reduced noise and improved CNRs without statistically significant differences in all subjective and objective criteria (p > 0.01) when the dose was reduced. Patients examined with a 260-mAs low-dose were exposed to a statistically significantly lower dose (1.77 vs 2.33 mSv; p < 0.01). CONCLUSION Iterative reconstruction (SAFIRE at strength level S4) leads to increased subjective and objective image quality in CCT and allows dose reduction (-24%) without losses in the demarcation of ischemic lesions.
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Ohno Y, Koyama H, Fujisawa Y, Yoshikawa T, Inokawa H, Sugihara N, Seki S, Sugimura K. Hybrid Type iterative reconstruction method vs. filter back projection method: Capability for radiation dose reduction and perfusion assessment on dynamic first-pass contrast-enhanced perfusion chest area-detector CT. Eur J Radiol 2015; 85:164-175. [PMID: 26724662 DOI: 10.1016/j.ejrad.2015.11.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 10/23/2015] [Accepted: 11/04/2015] [Indexed: 11/19/2022]
Abstract
PURPOSE To directly compare the capability of hybrid-type iterative reconstruction (i.e., adaptive iterative dose reduction using 3D processing: AIDR 3D) and filter back projection (FBP) for radiation dose reduction during dynamic contrast-enhanced (CE-) perfusion area-detector CT (ADCT) for lung and nodule perfusion assessment. MATERIALS AND METHODS Thirty-six patients with lung cancers who underwent perfusion ADCT (SD-ADCT) at 120 mA and were enrolled in this study. ADCT data at 80 mA (reduced-dose ADCT: RD-ADCT), 60 mA (low-dose ADCT: LD-ADCT) and 40 mA (very low-dose ADCT: VLD-ADCT) were computationally simulated using SD-ADCT data, and reconstructed with and without AIDR 3D. Image noise and lung and nodule perfusion parameters were evaluated using ROI measurements. To determine the utility of AIDR 3D for dose reduction, image noise was compared between each protocol with and without AIDR 3D by means of the t-test. Correlations and limits of agreement for parameters obtained with SD-ADCT and other protocols were also evaluated. RESULTS Image noise of all protocols with AIDR 3D was significantly lower than that of LD-ADCT and VLD-ADCT without AIDR 3D (p<0.05). Significant correlations for image noise between SD-ADCT and all protocols with AIDR 3D (0.45 ≤ r ≤ 0.99, p<0.0001) were equal to or better than that without AIDR 3D (0.28 ≤ r ≤ 0.99, p<0.0001). The limits of agreement for perfusion parameters with AIDR 3D were smaller than those without AIDR 3D for each tube current. CONCLUSION AIDR 3D is more effective than FBP for dose reduction of perfusion ADCT while maintaining image quality and reducing measurement errors.
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Affiliation(s)
- Yoshiharu Ohno
- Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.
| | - Hisanobu Koyama
- Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Yasuko Fujisawa
- Toshiba Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Takeshi Yoshikawa
- Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | | | - Naoki Sugihara
- Toshiba Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Shinichiro Seki
- Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Kazuro Sugimura
- Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
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