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Lee WC, Poon JK, Siah JJH, Chong MC, Lai C. Feasibility of low contrast volume and low injection flow rate in CT pulmonary angiography. J Med Imaging Radiat Sci 2024:101349. [PMID: 38897899 DOI: 10.1016/j.jmir.2023.11.009] [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: 09/21/2023] [Revised: 11/12/2023] [Accepted: 11/22/2023] [Indexed: 06/21/2024]
Abstract
BACKGROUND Computed Tomography Pulmonary Angiography (CTPA) is currently the gold standard for diagnosing Pulmonary Embolism (PE), with a high flowrate (>4.5ml/s) for contrast media (CM) administration recommended for sufficient pulmonary artery opacification. However, this may not be achievable for patients with challenging IV access. AIM To determine if a low volume CM, low flowrate (LVLF) CTPA protocol produces images of similar image quality compared to a standard protocol in two aspects, in terms of peak arterial enhancement through the quantitative measurement of Hounsfield unit (HU) and based on subjective overall image quality. METHODS Retrospective collection of 151 patients who underwent CTPA via 320 slice multi-detector CT due to clinical suspicion of PE. 80 patients underwent the standard protocol, with a fixed flowrate of 4.5ml/s and 50ml of CM, while 71 patients underwent the LVLF protocol with up to a 37% and 30% reduction in flowrate and CM administered, respectively. Two independent radiographers measured the attenuation of multiple pulmonary arteries in HU, with ≥200HU being considered diagnostic. Overall image quality was also reviewed using a 5-point close-ended questionnaire by two independent radiologists. RESULTS There was no significant difference in terms of attenuation measured in HU for the seven regions of interest (main pulmonary trunk, right and left pulmonary arteries, right and left lobar arteries, and right and left subsegmental arteries (RSA and LSA)) between the LVLF and standard CTPA protocol. Similarly, there were no significant differences in the overall image quality score obtained from standard and LVLF protocols reported by both radiologists. CONCLUSION The LVLF protocol can achieve similar enhancement and subjective image quality as the standard CTPA protocol, potentially allowing for further optimisation in the CM dosage.
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Affiliation(s)
- Wan Chin Lee
- Radiography, Changi General Hospital, Singapore.
| | - Jun Kai Poon
- Health and Social Science Cluster, Singapore Institute of Technology, Singapore, Singapore
| | | | | | - Christopher Lai
- Health and Social Science Cluster, Singapore Institute of Technology, Singapore, Singapore
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Schönfeld T, Seitz P, Krieghoff C, Ponorac S, Wötzel A, Olthoff S, Schaudt S, Steglich J, Gutberlet M, Gohmann RF. High-pitch CT pulmonary angiography (CTPA) with ultra-low contrast medium volume for the detection of pulmonary embolism: a comparison with standard CTPA. Eur Radiol 2024; 34:1921-1931. [PMID: 37656178 PMCID: PMC10873234 DOI: 10.1007/s00330-023-10101-8] [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: 12/29/2022] [Revised: 06/29/2023] [Accepted: 07/05/2023] [Indexed: 09/02/2023]
Abstract
OBJECTIVE To investigate the feasibility and image quality of high-pitch CT pulmonary angiography (CTPA) with reduced iodine volume in normal weight patients. METHODS In total, 81 normal weight patients undergoing CTPA for suspected pulmonary arterial embolism were retrospectively included: 41 in high-pitch mode with 20 mL of contrast medium (CM); and 40 with normal pitch and 50 mL of CM. Subjective image quality was assessed and rated on a 3-point scale. For objective image quality, attenuation and noise values were measured in all pulmonary arteries from the trunk to segmental level. Contrast-to-noise ratio (CNR) was calculated. Radiation dose estimations were recorded. RESULTS There were no statistically significant differences in patient and scan demographics between high-pitch and standard CTPA. Subjective image quality was rated good to excellent in over 90% of all exams with no significant group differences (p = 0.32). Median contrast opacification was lower in high-pitch CTPA (283.18 [216.06-368.67] HU, 386.81 [320.57-526.12] HU; p = 0.0001). CNR reached a minimum of eight in all segmented arteries, but was lower in high-pitch CTPA (8.79 [5.82-12.42], 11.01 [9.19-17.90]; p = 0.005). Median effective dose of high-pitch CTPA was lower (1.04 [0.72-1.27] mSv/mGy·cm; 1.49 [1.07-2.05] mSv/mGy·cm; p < 0.0001). CONCLUSION High-pitch CTPA using ultra-low contrast volume (20 mL) rendered diagnostic images for the detection of pulmonary arterial embolism in most instances. Compared to standard CTPA, the high-pitch CTPA exams with drastically reduced contrast medium volume had also concomitantly reduced radiation exposure. However, objective image quality of high-pitch CTPA was worse, though likely still within acceptable limits for confident diagnosis. CLINICAL RELEVANCE This study provides valuable insights on the performance of a high-pitch dual-source CTPA protocol, offering potential benefits in reducing contrast medium and radiation dose while maintaining sufficient image quality for accurate diagnosis in patients suspected of pulmonary embolism. KEY POINTS • High-pitch CT pulmonary angiography (CTPA) with ultra-low volume of contrast medium and reduced radiation dose renders diagnostic examinations with comparable subjective image quality to standard CTPA in most patients. • Objective image quality of high-pitch CTPA is reduced compared to standard CTPA, but contrast opacification and contrast-to-noise ratio remain above diagnostic thresholds. • Challenges of high-pitch CTPA may potentially be encountered in patients with severe heart failure or when performing a Valsalva maneuver during the examination.
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Affiliation(s)
- Tobias Schönfeld
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
- Department of General and Geriatric Medicine, St. Elisabeth-Hospital Leipzig, Biedermannstr. 84, 04277, Leipzig, Germany
- Medical Faculty, University of Leipzig, Liebigstr. 27, 04103, Leipzig, Germany
| | - Patrick Seitz
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - Christian Krieghoff
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - Slavica Ponorac
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
- Institute of Radiology, University Medical Centre Ljubljana, Zaloška Cesta 7, 1000, Ljubljana, Slovenia
| | - Alexander Wötzel
- Emergency Department, Helios Park-Clinic Leipzig, Strümpellstr. 41, 04289, Leipzig, Germany
| | - Stefan Olthoff
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - Sebastian Schaudt
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
- Medical Faculty, University of Leipzig, Liebigstr. 27, 04103, Leipzig, Germany
| | - Jonas Steglich
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - Matthias Gutberlet
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
- Medical Faculty, University of Leipzig, Liebigstr. 27, 04103, Leipzig, Germany
- Leipzig Heart Institute, Russenstr. 69a, 04289, Leipzig, Germany
| | - Robin F Gohmann
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany.
- Medical Faculty, University of Leipzig, Liebigstr. 27, 04103, Leipzig, Germany.
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Haubold J, Jost G, Theysohn JM, Ludwig JM, Li Y, Kleesiek J, Schaarschmidt BM, Forsting M, Nensa F, Pietsch H, Hosch R. Contrast Media Reduction in Computed Tomography With Deep Learning Using a Generative Adversarial Network in an Experimental Animal Study. Invest Radiol 2022; 57:696-703. [PMID: 35438659 DOI: 10.1097/rli.0000000000000875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE This feasibility study aimed to use optimized virtual contrast enhancement through generative adversarial networks (GAN) to reduce the dose of iodine-based contrast medium (CM) during abdominal computed tomography (CT) in a large animal model. METHODS Multiphasic abdominal low-kilovolt CTs (90 kV) with low (low CM, 105 mgl/kg) and normal contrast media doses (normal CM, 350 mgl/kg) were performed with 20 healthy Göttingen minipigs on 3 separate occasions for a total of 120 examinations. These included an early arterial, late arterial, portal venous, and venous contrast phase. One animal had to be excluded because of incomplete examinations. Three of the 19 animals were randomly selected and withheld for validation (18 studies). Subsequently, the GAN was trained for image-to-image conversion from low CM to normal CM (virtual CM) with the remaining 16 animals (96 examinations). For validation, region of interest measurements were performed in the abdominal aorta, inferior vena cava, portal vein, liver parenchyma, and autochthonous back muscles, and the contrast-to-noise ratio (CNR) was calculated. In addition, the normal CM and virtual CM data were presented in a visual Turing test to 3 radiology consultants. On the one hand, they had to decide which images were derived from the normal CM examination. On the other hand, they had to evaluate whether both images are pathological consistent. RESULTS Average vascular CNR (low CM 6.9 ± 7.0 vs virtual CM 28.7 ± 23.8, P < 0.0001) and parenchymal (low CM 1.5 ± 0.7 vs virtual CM 3.8 ± 2.0, P < 0.0001) CNR increased significantly by GAN-based contrast enhancement in all contrast phases and was not significantly different from normal CM examinations (vascular: virtual CM 28.7 ± 23.8 vs normal CM 34.2 ± 28.8; parenchymal: virtual CM 3.8 ± 2.0 vs normal CM 3.7 ± 2.6). During the visual Turing testing, the radiology consultants reported that images from normal CM and virtual CM were pathologically consistent in median in 96.5% of the examinations. Furthermore, it was possible for the examiners to identify the normal CM data as such in median in 91% of the cases. CONCLUSIONS In this feasibility study, it could be demonstrated in an experimental setting with healthy Göttingen minipigs that the amount of CM for abdominal CT can be reduced by approximately 70% by GAN-based contrast enhancement with satisfactory image quality.
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Affiliation(s)
- Johannes Haubold
- From the Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen
| | - Gregor Jost
- MR and CT Contrast Media Research, Bayer AG, Berlin
| | - Jens Matthias Theysohn
- From the Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen
| | - Johannes Maximilian Ludwig
- From the Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen
| | - Yan Li
- From the Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen
| | - Jens Kleesiek
- Institute of Artificial Intelligence in Medicine, University Hospital Essen, Germany
| | | | - Michael Forsting
- From the Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen
| | | | | | - René Hosch
- Institute of Artificial Intelligence in Medicine, University Hospital Essen, Germany
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Acute Pulmonary Embolism: Prognostic Role of Computed Tomography Pulmonary Angiography (CTPA). Tomography 2022; 8:529-539. [PMID: 35202207 PMCID: PMC8880178 DOI: 10.3390/tomography8010042] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 02/06/2022] [Accepted: 02/08/2022] [Indexed: 12/24/2022] Open
Abstract
Computed Tomography Pulmonary Angiography (CTPA) is considered the gold standard diagnostic technique in patients with suspected acute pulmonary embolism in emergency departments. Several studies have been conducted on the predictive value of CTPA on the outcomes of pulmonary embolism (PE). The purpose of this article is to provide an updated review of the literature reporting imaging parameters and quantitative CT scores to predict the severity of PE.
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Debnath J, Sharma V. Diagnosing pulmonary thromboembolism: Concerns and controversies. Med J Armed Forces India 2022; 78:17-23. [PMID: 35035039 PMCID: PMC8737094 DOI: 10.1016/j.mjafi.2021.05.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/24/2021] [Indexed: 01/03/2023] Open
Abstract
Pulmonary thromboembolism (PTE) is an important cause of mortality/morbidity even today despite advancement in clinical understanding as well as diagnostic facilities. Clinical diagnosis of PTE is often challenging because of nonspecific sign/symptoms. Adherence to clinical decision-making protocols and appropriate use of diagnostic modalities like computed tomography pulmonary angiography can resolve the diagnostic dilemma in most cases and help in the overall management of PTE. This article deals with various concerns as well as controversies surrounding accurate diagnosis of PTE as on date.
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Affiliation(s)
- Jyotindu Debnath
- Consultant, Professor & Head (Radiodiagnosis), Army Hospital (R&R), Delhi Cantt, India,Corresponding author.
| | - Vivek Sharma
- Professor (Radiodiagnosis), Bharati Vidyapeeth Medical College, Pune, India
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Haubold J, Hosch R, Umutlu L, Wetter A, Haubold P, Radbruch A, Forsting M, Nensa F, Koitka S. Contrast agent dose reduction in computed tomography with deep learning using a conditional generative adversarial network. Eur Radiol 2021; 31:6087-6095. [PMID: 33630160 PMCID: PMC8270814 DOI: 10.1007/s00330-021-07714-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/13/2020] [Accepted: 01/21/2021] [Indexed: 01/02/2023]
Abstract
OBJECTIVES To reduce the dose of intravenous iodine-based contrast media (ICM) in CT through virtual contrast-enhanced images using generative adversarial networks. METHODS Dual-energy CTs in the arterial phase of 85 patients were randomly split into an 80/20 train/test collective. Four different generative adversarial networks (GANs) based on image pairs, which comprised one image with virtually reduced ICM and the original full ICM CT slice, were trained, testing two input formats (2D and 2.5D) and two reduced ICM dose levels (-50% and -80%). The amount of intravenous ICM was reduced by creating virtual non-contrast series using dual-energy and adding the corresponding percentage of the iodine map. The evaluation was based on different scores (L1 loss, SSIM, PSNR, FID), which evaluate the image quality and similarity. Additionally, a visual Turing test (VTT) with three radiologists was used to assess the similarity and pathological consistency. RESULTS The -80% models reach an SSIM of > 98%, PSNR of > 48, L1 of between 7.5 and 8, and an FID of between 1.6 and 1.7. In comparison, the -50% models reach a SSIM of > 99%, PSNR of > 51, L1 of between 6.0 and 6.1, and an FID between 0.8 and 0.95. For the crucial question of pathological consistency, only the 50% ICM reduction networks achieved 100% consistency, which is required for clinical use. CONCLUSIONS The required amount of ICM for CT can be reduced by 50% while maintaining image quality and diagnostic accuracy using GANs. Further phantom studies and animal experiments are required to confirm these initial results. KEY POINTS • The amount of contrast media required for CT can be reduced by 50% using generative adversarial networks. • Not only the image quality but especially the pathological consistency must be evaluated to assess safety. • A too pronounced contrast media reduction could influence the pathological consistency in our collective at 80%.
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Affiliation(s)
- Johannes Haubold
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstraße 55, 45147, Essen, Germany.
| | - René Hosch
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstraße 55, 45147, Essen, Germany.,Institute for Artificial Intelligence in Medicine, University Hospital Essen, Essen, Germany
| | - Lale Umutlu
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Axel Wetter
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Patrizia Haubold
- Department of Diagnostic and Interventional Radiology, Kliniken Essen-Mitte, Essen, Germany
| | | | - Michael Forsting
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Felix Nensa
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstraße 55, 45147, Essen, Germany.,Institute for Artificial Intelligence in Medicine, University Hospital Essen, Essen, Germany
| | - Sven Koitka
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstraße 55, 45147, Essen, Germany.,Institute for Artificial Intelligence in Medicine, University Hospital Essen, Essen, Germany
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Aldosari S, Sun Z. A Systematic Review of Double Low-dose CT Pulmonary Angiography in Pulmonary Embolism. Curr Med Imaging 2020; 15:453-460. [PMID: 32008552 DOI: 10.2174/1573405614666180813120619] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 07/20/2018] [Accepted: 07/31/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND The aim of this study is to perform a systematic review of the feasibility and clinical application of double low-dose CT pulmonary angiography (CTPA) in the diagnosis of patients with suspected pulmonary embolism. DISCUSSION A total of 13 studies were found to meet selection criteria reporting both low radiation dose (70 or 80 kVp versus 100 or 120 kVp) and low contrast medium dose CTPA protocols. Lowdose CTPA resulted in radiation dose reduction from 29.6% to 87.5% in 12 studies (range: 0.4 to 23.5 mSv), while in one study, radiation dose was increased in the dual-energy CT group when compared to the standard 120 kVp group. CTPA with use of low contrast medium volume (range: 20 to 75 ml) was compared to standard CTPA (range: 50 to 101 ml) in 12 studies with reduction between 25 and 67%, while in the remaining study, low iodine concentration was used with 23% dose reduction achieved. Quantitative assessment of image quality (in terms of signal-to-noise ratio and contrast-to-noise ratio) showed that low-dose CTPA was associated with higher, lower and no change in image quality in 3, 3 and 6 studies, respectively when compared to the standard CTPA protocol. The subjective assessment indicated similar image quality in 11 studies between low-dose and standard CTPA groups, and improved image quality in 1 study with low-dose CTPA. CONCLUSION This review shows that double low-dose CTPA is feasible in the diagnosis of pulmonary embolism with significant reductions in both radiation and contrast medium doses, without compromising diagnostic image quality.
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Affiliation(s)
- Sultan Aldosari
- Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, Perth, Australia
| | - Zhonghua Sun
- Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, Perth, Australia
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Alobeidi H, Alshamari M, Widell J, Eriksson T, Lidén M. Minimizing contrast media dose in CT pulmonary angiography with high-pitch technique. Br J Radiol 2020; 93:20190995. [PMID: 32436788 PMCID: PMC7336071 DOI: 10.1259/bjr.20190995] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/30/2020] [Accepted: 04/23/2020] [Indexed: 02/01/2023] Open
Abstract
OBJECTIVES To perform CT pulmonary angiography (CTPA) using a minimal amount of iodinated contrast media. METHODS 47 patients (25 females) with mean age 69 years (range 41-82 years) referred for contrast-enhanced chest CT were prospectively included in this Phase IV clinical drug trial. All participants underwent a study specific CTPA in addition to the chest CT. The participants received 80 mg I/kg body weight Iohexol contrast media using a preparatory saline bolus, a dual flow contrast/saline bolus and a saline flush, and a scanner protocol with 80 kVp dual source high-pitch mode. Three readers independently assessed the image quality on the 3-point scale non-diagnostic, adequate or good-excellent image quality. Additionally, the pulmonary arterial contrast opacification was measured. RESULTS On average, the patients received 16.8 ml Iohexol 350 mg I/mL (range 12-20 ml). Mean patient weight was 71 kg (range 50-85 kg). Identically for all readers, pulmonary embolism (PE) was detected in 1/47 participants. The median number of examinations visually scored concerning pulmonary embolism as good-excellent was 47/47 (range 44-47); adequate 0/47 (0-3) and non-diagnostic 0/47 (range 0-0). The proportion adequate or better examinations was for all readers 47/47, 100% [95% confidence interval 92-100%]. The mean attenuation ± standard deviation in the pulmonary trunk was 325 ± 72 Hounsfield unit (range 165-531 Hounsfield unit). CONCLUSIONS Diagnostic CTPA with 17 ml contrast media is possible in non-obese patients using low kVp, high pitch and carefully designed contrast media administration. ADVANCES IN KNOWLEDGE By combining several procedures in a CTPA protocol, the contrast media dose can be minimized.
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Affiliation(s)
- Hanan Alobeidi
- Department of Radiology, Örebro university Hospital, Region Örebro län, S-70185 Örebro, Sweden
| | - Muhammed Alshamari
- Department of Radiology, Faculty of Medicine and Health, Örebro University, S-70182 Örebro, Sweden
| | - Jonas Widell
- Department of Radiology, Örebro university Hospital, Region Örebro län, S-70185 Örebro, Sweden
| | - Tomas Eriksson
- Department of Radiology, Örebro university Hospital, Region Örebro län, S-70185 Örebro, Sweden
| | - Mats Lidén
- Department of Radiology, Faculty of Medicine and Health, Örebro University, S-70182 Örebro, Sweden
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Tonkopi E, Manos D, Ross A. DOES THE USE OF CONTEMPORARY CT SCANNERS ALTER THE RADIATION DOSE DEBATE IN THE IMAGING WORK UP FOR PULMONARY EMBOLISM? RADIATION PROTECTION DOSIMETRY 2019; 187:353-360. [PMID: 31411698 DOI: 10.1093/rpd/ncz174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 07/05/2019] [Accepted: 07/08/2019] [Indexed: 06/10/2023]
Abstract
The aim of this study was to compare patient doses from ventilation perfusion single photon emission computed tomography (V/Q SPECT) and computed tomography pulmonary angiography (CTPA) performed on contemporary scanners. Effective dose (ED) for V/Q SPECT was calculated using organ doses per unit administered activity of the radiopharmaceuticals. Organ doses in CT were measured using nanoDot aluminium oxide optically stimulated dosemeters placed within a female adult anthropomorphic phantom. To simulate a larger patient, the phantom was wrapped in three layers of Superflab sheets. The V/Q SPECT resulted in ED of 2.82 mSv and a breast dose of 1.12 mGy. The CTPA dose was 1.82 ± 0.42 and 3.43 ± 0.91 mSv, whilst dose to the breast tissue was 2.86 ± 0.86 and 5.95 ± 0.44 mGy for small- and medium-sized patients, respectively.
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Affiliation(s)
- Elena Tonkopi
- Department of Diagnostic Radiology, Dalhousie University, 1276 South Park Street, PO BOX 9000, Halifax, NS, Canada B3H 2Y9
- Department of Diagnostic Imaging, NS Health Authority, 1276 South Park Street, PO BOX 9000, Halifax, NS, Canada B3H 2Y9
| | - Daria Manos
- Department of Diagnostic Radiology, Dalhousie University, 1276 South Park Street, PO BOX 9000, Halifax, NS, Canada B3H 2Y9
- Department of Diagnostic Imaging, NS Health Authority, 1276 South Park Street, PO BOX 9000, Halifax, NS, Canada B3H 2Y9
| | - Andrew Ross
- Department of Diagnostic Radiology, Dalhousie University, 1276 South Park Street, PO BOX 9000, Halifax, NS, Canada B3H 2Y9
- Department of Diagnostic Imaging, NS Health Authority, 1276 South Park Street, PO BOX 9000, Halifax, NS, Canada B3H 2Y9
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Ippolito D, De Vito A, Franzesi CT, Riva L, Pecorelli A, Corso R, Crespi A, Sironi S. Evaluation of image quality and radiation dose saving comparing knowledge model-based iterative reconstruction on 80-kV CT pulmonary angiography (CTPA) with hybrid iterative reconstruction on 100-kV CT. Emerg Radiol 2019; 26:145-153. [PMID: 30415416 DOI: 10.1007/s10140-018-1653-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 10/25/2018] [Indexed: 02/08/2023]
Abstract
OBJECTIVES To evaluate dose reduction and image quality of 80-kV CT pulmonary angiography (CTPA) reconstructed with knowledge model-based iterative reconstruction (IMR), and compared with 100-kV CTPA with hybrid iterative reconstruction (iDose4). MATERIALS AND METHODS One hundred and fifty-one patients were prospectively investigated for pulmonary embolism; a study group of 76 patients underwent low-kV setting (80 kV, automated mAs) CTPA study, while a control group of 75 patients underwent standard CTPA protocol (100 kV; automated mAs); all patients were examined on 256 MDCT scanner (Philips iCTelite). Study group images were reconstructed using IMR while the control group ones with iDose4. CTDIvol, DLP, and ED were evaluated. Region of interests placed in the main pulmonary vessels evaluated vascular enhancement (HU); signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. RESULTS Compared to iDose4-CTPA, low-kV IMR-CTPA presented lower CTDIvol (6.41 ± 0.84 vs 9.68 ± 3.5 mGy) and DLP (248.24 ± 3.2 vs 352.4 ± 3.59 mGy × cm), with ED of 3.48 ± 1.2 vs 4.93 ± 1.8 mSv. Moreover, IMR-CTPA showed higher values of attenuation (670.91 ± 9.09 HU vs 292.61 ± 15.5 HU) and a significantly higher SNR (p < 0.0001) and CNR (p < 0.0001).The subjective image quality of low-kV IMR-CTPA was also higher compared with iDose4-CTPA (p < 0.0001). CONCLUSIONS Low-dose CTPA (80 kV and automated mAs modulation) reconstructed with IMR represents a feasible protocol for the diagnosis of pulmonary embolism in the emergency setting, achieving high image quality with low noise, and a significant dose reduction within adequate reconstruction times(≤ 120 s).
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Affiliation(s)
- Davide Ippolito
- Department of Diagnostic Radiology, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, MB, Italy.
- School of Medicine, University of Milano-Bicocca, Via Cadore 48, 20900, Monza, MB, Italy.
| | - Andrea De Vito
- Department of Diagnostic Radiology, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, MB, Italy
- School of Medicine, University of Milano-Bicocca, Milan, MI, Italy
| | - Cammillo Talei Franzesi
- Department of Diagnostic Radiology, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, MB, Italy
- School of Medicine, University of Milano-Bicocca, Milan, MI, Italy
| | - Luca Riva
- Department of Diagnostic Radiology, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, MB, Italy
- School of Medicine, University of Milano-Bicocca, Milan, MI, Italy
| | - Anna Pecorelli
- Department of Diagnostic Radiology, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, MB, Italy
- School of Medicine, University of Milano-Bicocca, Via Cadore 48, 20900, Monza, MB, Italy
| | - Rocco Corso
- Department of Diagnostic Radiology, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, MB, Italy
| | - Andrea Crespi
- School of Medicine, University of Milano-Bicocca, Milan, MI, Italy
- Department of Medical Physics, "San Gerardo" Hospital, Monza, MB, Italy
| | - Sandro Sironi
- School of Medicine, University of Milano-Bicocca, Via Cadore 48, 20900, Monza, MB, Italy
- Department of Diagnostic Radiology, H Papa Giovanni XIII, Piazza OMS 1, 24127, Bergamo, BG, Italy
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