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Agostini A, Borgheresi A, Mariotti F, Ottaviani L, Carotti M, Valenti M, Giovagnoni A. New frontiers in oncological imaging with Computed Tomography: from morphology to function. Semin Ultrasound CT MR 2023; 44:214-227. [DOI: 10.1053/j.sult.2023.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Döllinger F, Elsner A, Hübner RH. [Computed tomographic imaging in chronic obstructive pulmonary disease : What pulmonologists and thoracic surgeons want to know]. RADIOLOGIE (HEIDELBERG, GERMANY) 2022; 62:747-757. [PMID: 35819467 DOI: 10.1007/s00117-022-01042-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
Chronic obstructive pulmonary disease (COPD) begins with chronic inflammation of the bronchial system and leads to the development of emphysema in many patients. COPD patients are characterized by reduced performance, dyspnea in the context of an obstructive respiratory disorder and increased susceptibility to infections. COPD has a major impact on public health, as it is very common and many patients die from it. The most important preventable cause of COPD is tobacco smoke inhalation, which is why consistent smoking cessation is the most important component of any COPD treatment. There is no causal therapy, but in severely symptomatic patients with advanced emphysema, respiratory mechanics can be improved by lung volume reduction if all conservative treatment options have been exhausted. Diagnostic imaging is of great importance in the care of COPD patients. This article summarizes which indications warrant the performance of computed tomography (CT) and what we should pay special attention to during image analysis in order to provide optimal advice to our clinical partners.
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Affiliation(s)
- Felix Döllinger
- Klinik für Radiologie, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Deutschland.
| | - Aron Elsner
- Chirurgische Klinik, Charité Universitätsmedizin Berlin, Berlin, Deutschland
| | - Ralf-Harto Hübner
- Medizinische Klinik m. S. Infektiologie und Pneumologie, Charité Universitätsmedizin Berlin, Berlin, Deutschland
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May M, Heiss R, Koehnen J, Wetzl M, Wiesmueller M, Treutlein C, Braeuer L, Uder M, Kopp M. Personalized Chest Computed Tomography: Minimum Diagnostic Radiation Dose Levels for the Detection of Fibrosis, Nodules, and Pneumonia. Invest Radiol 2022; 57:148-156. [PMID: 34468413 PMCID: PMC8826613 DOI: 10.1097/rli.0000000000000822] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 01/08/2023]
Abstract
OBJECTIVES The purpose of this study was to evaluate the minimum diagnostic radiation dose level for the detection of high-resolution (HR) lung structures, pulmonary nodules (PNs), and infectious diseases (IDs). MATERIALS AND METHODS A preclinical chest computed tomography (CT) trial was performed with a human cadaver without known lung disease with incremental radiation dose using tin filter-based spectral shaping protocols. A subset of protocols for full diagnostic evaluation of HR, PN, and ID structures was translated to clinical routine. Also, a minimum diagnostic radiation dose protocol was defined (MIN). These protocols were prospectively applied over 5 months in the clinical routine under consideration of the individual clinical indication. We compared radiation dose parameters, objective and subjective image quality (IQ). RESULTS The HR protocol was performed in 38 patients (43%), PN in 21 patients (24%), ID in 20 patients (23%), and MIN in 9 patients (10%). Radiation dose differed significantly among HR, PN, and ID (5.4, 1.2, and 0.6 mGy, respectively; P < 0.001). Differences between ID and MIN (0.2 mGy) were not significant (P = 0.262). Dose-normalized contrast-to-noise ratio was comparable among all groups (P = 0.087). Overall IQ was perfect for the HR protocol (median, 5.0) and decreased for PN (4.5), ID-CT (4.3), and MIN-CT (2.5). The delineation of disease-specific findings was high in all dedicated protocols (HR, 5.0; PN, 5.0; ID, 4.5). The MIN protocol had borderline IQ for PN and ID lesions but was insufficient for HR structures. The dose reductions were 78% (PN), 89% (ID), and 97% (MIN) compared with the HR protocols. CONCLUSIONS Personalized chest CT tailored to the clinical indications leads to substantial dose reduction without reducing interpretability. More than 50% of patients can benefit from such individual adaptation in a clinical routine setting. Personalized radiation dose adjustments with validated diagnostic IQ are especially preferable for evaluating ID and PN lesions.
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Affiliation(s)
- Matthias May
- From the Department of Radiology, University Hospital Erlangen
| | - Rafael Heiss
- From the Department of Radiology, University Hospital Erlangen
| | - Julia Koehnen
- From the Department of Radiology, University Hospital Erlangen
| | - Matthias Wetzl
- From the Department of Radiology, University Hospital Erlangen
| | | | | | - Lars Braeuer
- Institute of Anatomy, Chair II, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Michael Uder
- From the Department of Radiology, University Hospital Erlangen
| | - Markus Kopp
- From the Department of Radiology, University Hospital Erlangen
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Jungblut L, Blüthgen C, Polacin M, Messerli M, Schmidt B, Euler A, Alkadhi H, Frauenfelder T, Martini K. First Performance Evaluation of an Artificial Intelligence-Based Computer-Aided Detection System for Pulmonary Nodule Evaluation in Dual-Source Photon-Counting Detector CT at Different Low-Dose Levels. Invest Radiol 2022; 57:108-114. [PMID: 34324462 DOI: 10.1097/rli.0000000000000814] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the image quality (IQ) and performance of an artificial intelligence (AI)-based computer-aided detection (CAD) system in photon-counting detector computed tomography (PCD-CT) for pulmonary nodule evaluation at different low-dose levels. MATERIALS AND METHODS An anthropomorphic chest-phantom containing 14 pulmonary nodules of different sizes (range, 3-12 mm) was imaged on a PCD-CT and on a conventional energy-integrating detector CT (EID-CT). Scans were performed with each of the 3 vendor-specific scanning modes (QuantumPlus [Q+], Quantum [Q], and High Resolution [HR]) at decreasing matched radiation dose levels (volume computed tomography dose index ranging from 1.79 to 0.31 mGy) by adapting IQ levels from 30 to 5. Image noise was measured manually in the chest wall at 8 different locations. Subjective IQ was evaluated by 2 readers in consensus. Nodule detection and volumetry were performed using a commercially available AI-CAD system. RESULTS Subjective IQ was superior in PCD-CT compared with EID-CT (P < 0.001), and objective image noise was similar in the Q+ and Q-mode (P > 0.05) and superior in the HR-mode (PCD 55.8 ± 11.7 HU vs EID 74.8 ± 5.4 HU; P = 0.01). High resolution showed the lowest image noise values among PCD modes (P = 0.01). Overall, the AI-CAD system delivered comparable results for lung nodule detection and volumetry between PCD- and dose-matched EID-CT (P = 0.08-1.00), with a mean sensitivity of 95% for PCD-CT and of 86% for dose-matched EID-CT in the lowest evaluated dose level (IQ5). Q+ and Q-mode showed higher false-positive rates than EID-CT at lower-dose levels (IQ10 and IQ5). The HR-mode showed a sensitivity of 100% with a false-positive rate of 1 even at the lowest evaluated dose level (IQ5; CDTIvol, 0.41 mGy). CONCLUSIONS Photon-counting detector CT was superior to dose-matched EID-CT in subjective IQ while showing comparable to lower objective image noise. Fully automatized AI-aided nodule detection and volumetry are feasible in PCD-CT, but attention has to be paid to false-positive findings.
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Affiliation(s)
- Lisa Jungblut
- From the Institute of Diagnostic and Interventional Radiology
| | | | | | - Michael Messerli
- Department of Nuclear Medicine, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | | | - Andre Euler
- From the Institute of Diagnostic and Interventional Radiology
| | - Hatem Alkadhi
- From the Institute of Diagnostic and Interventional Radiology
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Abstract
Lung emphysema represents a major public health burden and still accounts for five percent of all deaths worldwide. Hence, it is essential to further understand this disease in order to develop effective diagnostic and therapeutic strategies. Lung emphysema is an irreversible enlargement of the airways distal to the terminal bronchi (i.e., the alveoli) due to the destruction of the alveolar walls. The two most important causes of emphysema are (I) smoking and (II) α1-antitrypsin-deficiency. In the former lung emphysema is predominant in the upper lung parts, the latter is characterized by a predominance in the basal areas of the lungs. Since quantification and evaluation of the distribution of lung emphysema is crucial in treatment planning, imaging plays a central role. Imaging modalities in lung emphysema are manifold: computed tomography (CT) imaging is nowadays the gold standard. However, emerging imaging techniques like dynamic or functional magnetic resonance imaging (MRI), scintigraphy and lately also the implementation of radiomics and artificial intelligence are more and more diffused in the evaluation, diagnosis and quantification of lung emphysema. The aim of this review is to shortly present the different subtypes of lung emphysema, to give an overview on prediction and risk assessment in emphysematous disease and to discuss not only the traditional, but also the new imaging techniques for diagnosis, quantification and evaluation of lung emphysema.
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Affiliation(s)
- Katharina Martini
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland
| | - Thomas Frauenfelder
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland
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Carotti M, Salaffi F, Sarzi-Puttini P, Agostini A, Borgheresi A, Minorati D, Galli M, Marotto D, Giovagnoni A. Chest CT features of coronavirus disease 2019 (COVID-19) pneumonia: key points for radiologists. Radiol Med 2020; 125:636-646. [PMID: 32500509 PMCID: PMC7270744 DOI: 10.1007/s11547-020-01237-4] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/25/2020] [Indexed: 12/15/2022]
Abstract
COVID-19 is an emerging infection caused by a novel coronavirus that is moving so rapidly that on 30 January 2020 the World Health Organization declared the outbreak a Public Health Emergency of International Concern and on 11 March 2020 as a pandemic. An early diagnosis of COVID-19 is crucial for disease treatment and control of the disease spread. Real-time reverse-transcription polymerase chain reaction (RT-PCR) demonstrated a low sensibility; therefore chest computed tomography (CT) plays a pivotal role not only in the early detection and diagnosis, especially for false negative RT-PCR tests, but also in monitoring the clinical course and in evaluating the disease severity. This paper reports the CT findings with some hints on the temporal changes over the course of the disease: the CT hallmarks of COVID-19 are bilateral distribution of ground glass opacities with or without consolidation in the posterior and peripheral lung, but the predominant findings in later phases include consolidations, linear opacities, “crazy-paving” pattern, “reversed halo” sign and vascular enlargement. The CT findings of COVID-19 overlap with the CT findings of other diseases, in particular the viral pneumonia including influenza viruses, parainfluenza virus, adenovirus, respiratory syncytial virus, rhinovirus, human metapneumovirus, etc. There are differences as well as similarities in the CT features of COVID-19 compared with those of the severe acute respiratory syndrome. The aim of this article is to review the typical and atypical CT findings in COVID-19 patients in order to help radiologists and clinicians to become more familiar with the disease.
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Affiliation(s)
- Marina Carotti
- Dipartimento di Scienze Radiologiche S. O. D. Radiologia Pediatrica e Specialistica, Azienda Ospedaliera Universitaria, Ospedali Riuniti "Umberto I-G.M. Lancisi-G. Salesi", Via Conca 71, 60030, Ancona, AN, Italy. .,Dipartimento di Scienze Cliniche Specialistiche e Odontostomatologiche, University Politecnica delle Marche, Ancona, AN, Italy.
| | - Fausto Salaffi
- Clinica Reumatologica, Ospedale "Carlo Urbani", Jesi, AN, Italy.,Dipartimento di Scienze Cliniche e Molecolari, University Politecnica delle Marche, Ancona, AN, Italy
| | - Piercarlo Sarzi-Puttini
- Divisione di Reumatologia, Dipartimento di Medicina Interna, ASST Fatebenefratelli-Sacco, Milan University School of Medicine, Milan, Italy
| | - Andrea Agostini
- Dipartimento di Scienze Radiologiche S. O. D. Radiologia Pediatrica e Specialistica, Azienda Ospedaliera Universitaria, Ospedali Riuniti "Umberto I-G.M. Lancisi-G. Salesi", Via Conca 71, 60030, Ancona, AN, Italy.,Dipartimento di Scienze Cliniche Specialistiche e Odontostomatologiche, University Politecnica delle Marche, Ancona, AN, Italy
| | - Alessandra Borgheresi
- Dipartimento di Scienze Radiologiche S. O. D. Radiologia Pediatrica e Specialistica, Azienda Ospedaliera Universitaria, Ospedali Riuniti "Umberto I-G.M. Lancisi-G. Salesi", Via Conca 71, 60030, Ancona, AN, Italy
| | - Davide Minorati
- Dipartimento di Radiologia. ASST Fatebenefratelli-Sacco, Milan University School of Medicine, Milan, Italy
| | - Massimo Galli
- Divisione di Malattie Infettive, Department di Scienze Cliniche e Biomolecolari, ASST Fatebenefratelli-Sacco, Milan University School of Medicine, Milan, Italy
| | - Daniela Marotto
- Divisione di Reumatologia, Dipartimento di Medicina Interna, ASST Fatebenefratelli-Sacco, Milan University School of Medicine, Milan, Italy
| | - Andrea Giovagnoni
- Dipartimento di Scienze Radiologiche S. O. D. Radiologia Pediatrica e Specialistica, Azienda Ospedaliera Universitaria, Ospedali Riuniti "Umberto I-G.M. Lancisi-G. Salesi", Via Conca 71, 60030, Ancona, AN, Italy.,Dipartimento di Scienze Cliniche Specialistiche e Odontostomatologiche, University Politecnica delle Marche, Ancona, AN, Italy
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Martini K, Moon JW, Revel MP, Dangeard S, Ruan C, Chassagnon G. Optimization of acquisition parameters for reduced-dose thoracic CT: A phantom study. Diagn Interv Imaging 2020; 101:269-279. [PMID: 32107196 DOI: 10.1016/j.diii.2020.01.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/23/2020] [Accepted: 01/28/2020] [Indexed: 02/06/2023]
Abstract
PURPOSE The purpose of this study was to analyze the impact of different options for reduced-dose computed tomography (CT) on image noise and visibility of pulmonary structures in order to define the best choice of parameters when performing ultra-low dose acquisitions of the chest in clinical routine. MATERIALS AND METHODS Using an anthropomorphic chest phantom, CT images were acquired at four defined low dose levels (computed tomography dose index [CTDIvol]=0.15, 0.20, 0.30 and 0.40mGy), by changing tube voltage, pitch factor, or rotation time and adapting tube current to reach the predefined CTDIvol-values. Images were reconstructed using two different levels of iteration (adaptive statistical iterative reconstruction [ASIR®]-v70% and ASIR®-v100%). Signal-to-noise ratio (SNR) as well as contrast-to-noise ratio (CNR) was calculated. Visibility of pulmonary structures (bronchi/vessels) were assessed by two readers on a 5-point-Likert scale. RESULTS Best visual image assessments and CNR/SNR were obtained with high tube voltage, while lowest scores were reached with lower pitch factor followed by high tube current. Protocols favoring lower pitch factor resulted in decreased visibility of bronchi/vessels, especially in the periphery. Decreasing radiation dose from 0.40 to 0.30mGy was not associated with a significant decrease in visual scores (P<0.05), however decreasing radiation dose from 0.30mGy to 0.15mGy was associated with a lower visibility of most of the evaluated structures (P<0.001). While image noise could be significantly reduced when ASIR®-v100% instead of ASIR®-v70% was used, the visibility-scores of pulmonary structures did not change significantly. CONCLUSION Favoring high tube voltage is the best option for reduced-dose protocols. A decrease of SNR and CNR does not necessarily go along with reduced visibility of pulmonary structures.
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Affiliation(s)
- K Martini
- Department of Radiology, Cochin Hospital, AP-HP Centre, 75014 Paris, France; Diagnostic and Interventional Radiology, University Hospital Zurich, 8008 Zurich, Switzerland
| | - J W Moon
- Department of Radiology, Cochin Hospital, AP-HP Centre, 75014 Paris, France
| | - M P Revel
- Department of Radiology, Cochin Hospital, AP-HP Centre, 75014 Paris, France; Université de Paris, Descartes-Paris 5, 75006 Paris, France
| | - S Dangeard
- Department of Radiology, Cochin Hospital, AP-HP Centre, 75014 Paris, France
| | - C Ruan
- General Electric Healthcare, 78530 Buc, France
| | - G Chassagnon
- Department of Radiology, Cochin Hospital, AP-HP Centre, 75014 Paris, France; Université de Paris, Descartes-Paris 5, 75006 Paris, France; Center for Visual Computing, École Centrale Supelec, 91190 Gif-sur-Yvette, France.
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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: 63] [Impact Index Per Article: 12.6] [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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Venous-phase chest CT with reduced contrast medium dose: Utilization of spectral low keV monoenergetic images improves image quality. Eur J Radiol 2019; 122:108756. [PMID: 31786505 DOI: 10.1016/j.ejrad.2019.108756] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/06/2019] [Accepted: 11/18/2019] [Indexed: 11/21/2022]
Abstract
PURPOSE Intravenous contrast administration is crucial in many CT examinations but also poses a potential risk to the patient. Monoenergetic images (MonoE) of dual-energy CT systems can virtually increase iodine attenuation and might improve image quality (IQ) if contrast dose is reduced. In this study, we investigated the influence of MonoE on lymph node (LN) delineation and IQ in chest CT examinations with significantly reduced contrast dose (50 %) of a novel dual-layer CT (DLCT). METHOD 30 patients with clinically indicated reduced contrast dose underwent venous-phase chest DLCT scans. Conventional polyenergetic (PolyE) and MonoE images at 40 keV were calculated. The contrast difference of hilar lymph nodes (LN-CD) to the adjacent right pulmonary artery, their signal-to-noise (SNR) and contrast-to-noise-ratio (CNR) were determined. Subjective IQ was evaluated by 2 readers with respect to LN delineation and overall contrast enhancement (CE) using a 5-point-Likert-scale. RESULTS LN-CD, SNR and CNR were significantly higher in MonoE than in PolyE images (LN-CD 92.3 ± 37.9 vs. 33.1 ± 14.5 HU, SNR 8.4 ± 3.4 vs. 4.0 ± 1.2, CNR 9.2 ± 6.3 vs. 2.6 ± 1.5; all p < 0.01). The LN delineation (3.7 ± 0.9 vs.1.8 ± 0.7; p < 0.01) and the CE (3.9 ± 0.7 vs. 2.3 ± 0.7; p < 0.01) were rated significantly better for MonoE than for PolyE images. There was no MonoE examination classified as non-diagnostic. CONCLUSIONS Subjective and objective IQ parameters can be significantly improved for venous-phase chest CT examinations with reduced contrast doses by utilization of low-keV MonoE reconstructions. All MonoE images provided sufficient overall CE and therefore reduced contrast doses might be considered in a wider range of DLCT examinations and patients.
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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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Jin S, Zhang B, Zhang L, Li S, Li S, Li P. Lung nodules assessment in ultra-low-dose CT with iterative reconstruction compared to conventional dose CT. Quant Imaging Med Surg 2018; 8:480-490. [PMID: 30050782 DOI: 10.21037/qims.2018.06.05] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background To retrospectively assess whether the low-voltage lung CT scan coupled with iterative reconstruction algorithms can be an optimal scanning method for measuring the size and density of lung nodules in cancer patients. Methods Eighty two cancer patients receiving both chest scan with low-voltage (80 kV) and abdomen CT scan with standard voltage (120 kV) were enrolled in this study. Lung nodules were measured manually and semi-automatically by two different computer-aided diagnosis (CAD) systems. The nodules were then divided into large-, medium- and small-size groups based on their largest diameter. Additionally, the nodules were categorized into three different groups according to their density: calcified, solid and partial-solid nodules. The 3D volumes, average diameter and CT value of lung nodules were measured using the two CAD semi-automated systems, and the CT values were compared with regards to the different tube voltages. Furthermore, the accuracy and reliability of CAD systems were validated in the large nodules. Results The scores of subjective evaluation indicated that the quality of lung nodule images yielded optimal clinical diagnostic value for both 80 kV (2.35±0.054) and 120 kV (2.51±0.053) scanning methods, with a strong inter-observer consistency (Kappa =0.848 and 0.829, respectively). Intraclass correlation coefficient (ICC) and Bland-Altman plot revealed that two CAD systems produced the consistent results. Mean CT values of large nodules (n=18) were significantly different between 80 and 120 kV (-28.11±47.39 vs. -39.61±43.32 HU, P<0.05). Notably, the CT value of 80 kV was 33.96% higher than that of 120 kV. Moreover, the volumes of 66 solid lung nodules demonstrated a statistically significant difference (1.68%) between 80 kV group (740.89±156.97 mm3) and 120 kV group (753.48±157.92 mm3, P<0.05). Furthermore, significant differences were observed in the CT values of large nodules between 80 and 120 kV groups (25.64±12.67 vs. 13.89±9.78 HU, P<0.05), but not the maximum diameters (12.08±1.56 vs. 12.13±1.56 mm, P>0.05). Conclusions Our study suggests that detection of lung nodules with ultra-low-dose CT can yield an excellent image quality and optimal diagnostic values as compared to the standard dose CT. Therefore, CT scan with low voltage of 80 kV CT scan can be leveraged to improve the diagnosis and surveillance of lung nodules measured less than 30 mm in diameter. Further investigation with a larger sample size is warranted to confirm our findings, particularly the increased CT values of large nodules and the greater volume of solid nodules after exposure to low-dose CT scan.
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Affiliation(s)
- Shiqi Jin
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, China
| | - Bo Zhang
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, China
| | - Lina Zhang
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, China
| | - Shu Li
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, China
| | - Songbai Li
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, China
| | - Peiling Li
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, China
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Ali Khawaja RD, Singh S, Padole A, Otrakji A, Lira D, Zhang D, Liu B, Primak A, Xu G, Kalra MK. Point Organ Radiation Dose in Abdominal CT: Effect of Patient Off-Centering in an Experimental Human Cadaver Study. RADIATION PROTECTION DOSIMETRY 2017; 175:440-449. [PMID: 28074019 PMCID: PMC5927332 DOI: 10.1093/rpd/ncw371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 11/25/2016] [Accepted: 12/02/2016] [Indexed: 06/06/2023]
Abstract
To determine the effect of patient off-centering on point organ radiation dose measurements in a human cadaver scanned with routine abdominal CT protocol. A human cadaver (88 years, body-mass-index 20 kg/m2) was scanned with routine abdominal CT protocol on 128-slice dual source MDCT (Definition Flash, Siemens). A total of 18 scans were performed using two scan protocols (a) 120 kV-200 mAs fixed-mA (CTDIvol 14 mGy) (b) 120 kV-125 ref mAs (7 mGy) with automatic exposure control (AEC, CareDose 4D) at three different positions (a) gantry isocenter, (b) upward off-centering and (c) downward off-centering. Scanning was repeated three times at each position. Six thimble (in liver, stomach, kidney, pancreas, colon and urinary bladder) and four MOSFET dosimeters (on cornea, thyroid, testicle and breast) were placed for calculation of measured point organ doses. Organ dose estimations were retrieved from dose-tracking software (eXposure, Radimetrics). Statistical analysis was performed using analysis of variance. There was a significant difference between the trends of point organ doses with AEC and fixed-mA at all three positions (p < 0.01). Variation in point doses between fixed-mA and AEC protocols were statistically significant across all organs at all Table positions (p < 0.001). There was up to 5-6% decrease in point doses with upward off-centering and in downward off-centering. There were statistical significant differences in point doses from dosimeters and dose-tracking software (mean difference for internal organs, 5-36% for fixed-mA & 7-48% for AEC protocols; p < 0.001; mean difference for surface organs, >92% for both protocols; p < 0.0001). For both protocols, the highest mean difference in point doses was found for stomach and lowest for colon. Measured absorbed point doses in abdominal CT vary with patient-centering in the gantry isocenter. Due to lack of consideration of patient positioning in the dose estimation on automatic software-over estimation of the doses up to 92% was reported.
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Affiliation(s)
| | - Sarabjeet Singh
- MGH Imaging, Massachusetts General Hospital, Fruit St, Boston, MA 02114, USA
| | - Atul Padole
- MGH Imaging, Massachusetts General Hospital, Fruit St, Boston, MA 02114, USA
| | - Alexi Otrakji
- MGH Imaging, Massachusetts General Hospital, Fruit St, Boston, MA 02114, USA
| | - Diego Lira
- MGH Imaging, Massachusetts General Hospital, Fruit St, Boston, MA 02114, USA
| | - Da Zhang
- MGH Imaging, Massachusetts General Hospital, Fruit St, Boston, MA 02114, USA
| | - Bob Liu
- MGH Imaging, Massachusetts General Hospital, Fruit St, Boston, MA 02114, USA
| | | | - George Xu
- Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Mannudeep K. Kalra
- MGH Imaging, Massachusetts General Hospital, Fruit St, Boston, MA 02114, USA
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Martini K, Barth BK, Higashigaito K, Baumueller S, Alkadhi H, Frauenfelder T. Dose-Optimized Computed Tomography for Screening and Follow-Up of Solid Pulmonary Nodules in Obesity: A Phantom Study. Curr Probl Diagn Radiol 2017; 46:204-209. [DOI: 10.1067/j.cpradiol.2016.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 06/13/2016] [Accepted: 07/28/2016] [Indexed: 12/21/2022]
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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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Padole A, Digumarthy S, Flores E, Madan R, Mishra S, Sharma A, Kalra MK. Assessment of chest CT at CTDI vol less than 1 mGy with iterative reconstruction techniques. Br J Radiol 2017; 90:20160625. [PMID: 28055250 DOI: 10.1259/bjr.20160625] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE To assess the image quality of chest CT reconstructed with image-based iterative reconstruction (SafeCT; MedicVision®, Tirat Carmel, Israel), adaptive statistical iterative reconstruction (ASIR; GE Healthcare, Waukesha, WI) and model-based iterative reconstruction (MBIR; GE Healthcare, Waukesha, WI) techniques at CT dose index volume (CTDIvol) <1 mGy. METHODS In an institutional review board-approved study, 25 patients gave written informed consent for acquisition of three reduced dose (0.25-, 0.4- and 0.8-mGy) chest CT after standard of care CT (8 mGy) on a 64-channel multidetector CT (MDCT) and reconstructed with SafeCT, ASIR and MBIR. Two board-certified thoracic radiologists evaluated images from the lowest to the highest dose of the reduced dose CT series and subsequently for standard of care CT. RESULTS Out of the 182 detected lesions, the missed lesions were 35 at 0.25, 24 at 0.4 and 9 at 0.8 mGy with SafeCT, ASIR and MBIR, respectively. The most missed lesions were non-calcified lung nodules (NCLNs) 25/112 (<5 mm) at 0.25, 18/112 (<5 mm) at 0.4 and 3/112 (<4 mm) at 0.8 mGy. There were 78%, 84% and 97% lung nodules detected at 0.25, 0.4 and 0.8 mGy, respectively regardless of iterative reconstruction techniques (IRTs), Most mediastinum structures were not sufficiently seen at 0.25-0.8 mGy. CONCLUSION NCLNs can be missed in chest CT at CTDIvol of <1 mGy (0.25, 0.4 and 0.8 mGy) regardless of IRTs. The most lung nodules (97%) were detected at CTDIvol of 0.8 mGy. The most mediastinum structures were not sufficiently seen at 0.25-0.8 mGy. Advances in knowledge: NCLNs can be missed regardless of IRTs in chest CT at CTDIvol of <1 mGy. The performance of ASIR, SafeCT and MBIR was similar for lung nodule detection at 0.25, 0.4 and 0.8 mGy.
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Affiliation(s)
- Atul Padole
- 1 Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Subba Digumarthy
- 1 Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Efren Flores
- 1 Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Rachna Madan
- 2 Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA
| | - Shelly Mishra
- 1 Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Amita Sharma
- 1 Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Mannudeep K Kalra
- 1 Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
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Thoracic lymph node delineation at dose-reduced (1 mSv) dose-modulated contrast enhanced MDCT: a retrospective pilot study. Radiol Med 2016; 121:644-51. [DOI: 10.1007/s11547-016-0645-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/18/2016] [Indexed: 11/27/2022]
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Abstract
PURPOSE OF REVIEW The purpose of this review is to provide an up-to-date summary of developments in medical imaging in the diagnosis, surveillance, treatment, and screening of occupational and environmental lung diseases, focusing on articles published within the past 2 years. RECENT FINDINGS Many new exposures resulting in lung disease have been described worldwide; medical imaging, particularly computed tomography (CT), is often pivotal in recognition and characterization of these new patterns of lung injury. Chest radiography remains important to surveillance studies tracking the long-term evolution of disease and effectiveness of air quality regulation. Finally, studies are proving the utility of screening with low-dose CT, and technical advances offer the prospect of further CT dose reduction with ultra-low-dose CT. SUMMARY In understanding the best practices and new developments in medical imaging, the occupational and environmental medicine clinician can optimize diagnosis and management of related lung diseases.
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Evaluation of pulmonary nodules and infection on chest CT with radiation dose equivalent to chest radiography: Prospective intra-individual comparison study to standard dose CT. Eur J Radiol 2015; 85:360-5. [PMID: 26781141 DOI: 10.1016/j.ejrad.2015.11.036] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/26/2015] [Accepted: 11/27/2015] [Indexed: 12/20/2022]
Abstract
PURPOSE To compare prospectively, in patients undergoing chest computed tomography (CT) for pulmonary-nodules or infection, image-quality and accuracy of standard dose (SD) and reduced dose (RD) CT with tin-filtration. MATERIAL AND METHODS This IRB-approved study included 100 consecutive patients (36 female;median age 56 years) referred for follow-up of pulmonary-nodules (n=43) or suspicion of infection (n=57) undergoing single-energy CT with SD and RD using tin-filtration at 100 kVp (CTDIvol 2.47 mGy and 0.07 mGy, respectively). Images were reconstructed with advanced modeled iterative reconstruction (ADMIRE) at strength 3 and 5. Image-noise was measured. Two independent readers evaluated nodules and pulmonary-infection. SD CT served as reference standard. RESULTS No significant difference was found in noise between RD with ADMIRE5 and SD with ADMIRE3 (118HU ± 14 vs. 120HU ± 17; p=0.08). Sensitivity for detection of atelectasis and interstitial lung changes was higher in images reconstructed with ADMIRE5 (93% and 88%; respectively) than in those reconstructed with ADIMRE3 (77% and 78%; respectively). Sensitivity for detection of consolidations was 90% for ADMIRE3 and 89% for ADMIRE5. Sensitivity for nodule detection was 71% for ADMIRE3 and 81% for ADMIRE5. Specificity for detection of atelectasis and interstitial lung changes was 99% and 96% with ADMIRE5 and 99% and 96% with ADMIRE3. Specificity for detection of consolidations was 99% for ADMIRE3 and 5. Specificity for detection of nodules was 87% for both ADMIRE3 and 5. CONCLUSION Chest CT with a radiation dose equivalent to conventional radiography is feasible and allows for detection of pulmonary infection with high sensitivity, whereas the accuracy for detecting nodules is only moderate.
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Thaiss WM, Sauter AW, Bongers M, Horger M, Nikolaou K. Clinical applications for dual energy CT versus dynamic contrast enhanced CT in oncology. Eur J Radiol 2015; 84:2368-79. [DOI: 10.1016/j.ejrad.2015.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 06/02/2015] [Indexed: 12/12/2022]
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Martini K, Higashigaito K, Barth BK, Baumueller S, Alkadhi H, Frauenfelder T. Ultralow-dose CT with tin filtration for detection of solid and sub solid pulmonary nodules: a phantom study. Br J Radiol 2015; 88:20150389. [PMID: 26492317 DOI: 10.1259/bjr.20150389] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES To investigate the diagnostic performance of advanced modelled iterative reconstruction (ADMIRE) to filtered back projection (FBP) when using an ultralow-dose protocol for the detection of solid and subsolid pulmonary nodules. METHODS Single-energy CT was performed at 100 kVp with tin filtration in an anthropomorphic chest phantom with solid and subsolid pulmonary nodules (2-10 mm, attenuation, 20 to -800 HU at 120 kVp). The mean volume CT dose index (CTDIvol) of the standard chest protocol was 2.2 mGy. Subsequent scans were obtained at 1/8 (0.28 mGy), 1/20 (0.10 mGy) and 1/70 (0.03 mGy) dose levels by lowering tube voltage and tube current. Images were reconstructed with FBP and ADMIRE. One reader measured image noise; two readers determined image quality and assessed nodule localization. RESULTS Image noise was significantly reduced using ADMIRE compared with FBP (ADMIRE at a strength level of 5 : 70.4% for 1/20; 71.6% for 1/8; p < 0.001). Interobserver agreement for image quality was excellent (k = 0.88). Image quality was considered diagnostic for all images at 1/20 dose using ADMIRE. Sensitivity of nodule detection was 97.1% (100% for solid, 93.8% for subsolid nodules) at 1/20 dose and 100% for both nodule entities at 1/8 dose using ADMIRE 5. Images obtained with 1/70 dose had moderate sensitivity (overall 85.7%; solid 95%; subsolid 73.3%). CONCLUSION Our study suggests that with a combination of tin filtration and ADMIRE, the CTDIvol of chest CT can be lowered considerably, while sensitivity for nodule detection remains high. For solid nodules, CTDIvol was 0.10 mGy, while subsolid nodules required a slightly higher CTDIvol of 0.28 mGy. ADVANCES IN KNOWLEDGE Detection of subsolid nodules is feasible with ultralow-dose protocols.
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Affiliation(s)
- Katharina Martini
- University Hospital Zurich, Department of Diagnostic and Interventional Radiology/University of Zurich, Zurich, Switzerland
| | - Kai Higashigaito
- University Hospital Zurich, Department of Diagnostic and Interventional Radiology/University of Zurich, Zurich, Switzerland
| | - Borna K Barth
- University Hospital Zurich, Department of Diagnostic and Interventional Radiology/University of Zurich, Zurich, Switzerland
| | - Stephan Baumueller
- University Hospital Zurich, Department of Diagnostic and Interventional Radiology/University of Zurich, Zurich, Switzerland
| | - Hatem Alkadhi
- University Hospital Zurich, Department of Diagnostic and Interventional Radiology/University of Zurich, Zurich, Switzerland
| | - Thomas Frauenfelder
- University Hospital Zurich, Department of Diagnostic and Interventional Radiology/University of Zurich, Zurich, Switzerland
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