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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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Saeed S, Niehoff JH, Boriesosdick J, Michael A, Woeltjen MM, Surov A, Moenninghoff C, Borggrefe J, Kroeger JR. Minimizing Contrast Media Dose in CT Pulmonary Angiography with Clinical Photon Counting Using High Pitch Technique. Acad Radiol 2024; 31:686-692. [PMID: 37393176 DOI: 10.1016/j.acra.2023.05.018] [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: 03/09/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 07/03/2023]
Abstract
RATIONALE AND OBJECTIVES To evaluate the potential to reduce the amount of iodinated contrast media (CM) for computer tomographic pulmonary angiography (CTPA) with a novel photon-counting-detector CT (PCCT). MATERIALS AND METHODS Overall, 105 patients referred for CTPA were retrospectively included in this study. CTPA was performed using bolus tracking and high-pitch dual-source scanning (FLASH mode) on a novel PCCT (Naeotom Alpha, Siemens Healthineers). CM (Accupaque 300, GE Healthcare) dose was lowered stepwise following the introduction of the new CT scanner. Thus, patients could be divided into 3 groups as follows: group 1, n = 29, 35 ml of CM; group 2, n = 62, 45 ml of CM and group 3, n = 14, 60 ml of CM. Four readers independently assessed the image quality (Likert-scale 1-5) and adequate assessment of the segmental pulmonary arteries. Additionally, the pulmonary arterial contrast opacification was measured. RESULTS The subjective image quality was rated highest in group 1 with 4.6 compared to 4.5 (group 2) and 4.1 (group 3) with a significant difference between groups 1 and 3 (p < 0.001) and between groups 2 and 3 (p = 0.003). In all groups, almost all segmental pulmonary arteries could be assessed adequately without significant differences (18.5 vs. 18.7 vs. 18.4). Mean attenuation in the pulmonary trunk did not differ significantly between groups 321 ± 92 HU versus 345 ± 93 HU versus 347 ± 88 HU (p = 0.69). CONCLUSION Significant CM dose reduction is possible without a reduction in image quality. PCCT enables diagnostic CTPA with 35 ml of CM.
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Affiliation(s)
- Saher Saeed
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, Bochum, Germany.
| | - Julius H Niehoff
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Jan Boriesosdick
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Arwed Michael
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Matthias M Woeltjen
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Alexey Surov
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Christoph Moenninghoff
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Jan Borggrefe
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Jan Robert Kroeger
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, Bochum, Germany
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Pannenbecker P, Heidenreich JF, Grunz JP, Huflage H, Gruschwitz P, Patzer TS, Feldle P, Bley TA, Petritsch B. Image Quality and Radiation Dose of CTPA With Iodine Maps: A Prospective Randomized Study of High-Pitch Mode Photon-Counting Detector CT Versus Energy-Integrating Detector CT. AJR Am J Roentgenol 2024; 222:e2330154. [PMID: 37966036 DOI: 10.2214/ajr.23.30154] [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] [Indexed: 11/16/2023]
Abstract
BACKGROUND. Dual-energy CT pulmonary angiography (CTPA) with energy-integrating detector (EID) technology is limited by the inability to use high-pitch technique. OBJECTIVE. The purpose of this study was to compare the image quality of anatomic images and iodine maps between high-pitch photon-counting detector (PCD) CTPA and dual-energy EID CTPA. METHODS. This prospective study included 117 patients (70 men and 47 women; median age, 65 years) who underwent CTPA to evaluate for pulmonary embolism between March 2022 and November 2022. Fifty-eight patients were randomized to undergo PCD CTPA (pitch, 2.0), and 59 were randomized to undergo EID CTPA (pitch, 0.55). For each examination, 120-kV polychromatic images, 60-keV virtual monogenetic images (VMIs), and iodine maps were reconstructed. One radiologist measured CNR and SNR. Three radiologists independently assessed subjective image quality (on a scale of 1-4, with a score of 1 denoting highest quality). Radiation dose was recorded. RESULTS. SNR and CNR were higher for PCD CTPA than for EID CTPA for polychromatic images and VMIs, for all assessed vessels other than the left upper lobe artery. For example, for PCD CTPA versus EID CTPA, the right lower lobe artery on polychromatic images had an SNR of 34.5 versus 28.0 (p = .003) and a CNR of 29.2 versus 24.4 (p = .001), and on VMIs it had an SNR of 43.2 versus 32.7 (p = .005) and a CNR of 37.4 versus 29.3 (p = .002). For both scanners for readers 1 and 2, the median image quality score for polychromatic images and VMIs was 1, although distributions indicated significantly better scores for PCD CTPA than for EID CTPA for polychromatic images for reader 1 (p = .02) and reader 2 (p = .005) and for VMIs for reader 1 (p = .001) and reader 2 (p = .006). The image quality of anatomic image sets was not different between PCD CTPA and EID CTPA for reader 3 (p > .05). The image quality of iodine maps was not different between PCD CTPA and EID CTPA for any reader (p > .05). For PCD CTPA versus EID CTPA, the CTDIvol was 3.9 versus 4.5 mGy (p = .03), and the DLP was 123.5 mGy × cm versus 157.0 mGy × cm (p < .001). CONCLUSION. High-pitch PCD CTPA provided anatomic images with better subjective and objective image quality versus dual-energy EID CTPA, with lower radiation dose. Iodine maps showed no significant difference in image quality between scanners. CLINICAL IMPACT. CTPA may benefit from the PCD CT technique.
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Affiliation(s)
- Pauline Pannenbecker
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Julius F Heidenreich
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Philipp Gruschwitz
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Theresa S Patzer
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Philipp Feldle
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Thorsten A Bley
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Bernhard Petritsch
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
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Pannenbecker P, Huflage H, Grunz JP, Gruschwitz P, Patzer TS, Weng AM, Heidenreich JF, Bley TA, Petritsch B. Photon-counting CT for diagnosis of acute pulmonary embolism: potential for contrast medium and radiation dose reduction. Eur Radiol 2023; 33:7830-7839. [PMID: 37311805 PMCID: PMC10598187 DOI: 10.1007/s00330-023-09777-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 04/07/2023] [Accepted: 04/11/2023] [Indexed: 06/15/2023]
Abstract
OBJECTIVE To evaluate the image quality of an ultra-low contrast medium and radiation dose CT pulmonary angiography (CTPA) protocol for the diagnosis of acute pulmonary embolism using a clinical photon-counting detector (PCD) CT system and compare its performance to a dual-energy-(DE)-CTPA protocol on a conventional energy-integrating detector (EID) CT system. METHODS Sixty-four patients either underwent CTPA with the novel scan protocol on the PCD-CT scanner (32 patients, 25 mL, CTDIvol 2.5 mGy·cm) or conventional DE-CTPA on a third-generation dual-source EID-CT (32 patients, 50 mL, CTDIvol 5.1 mGy·cm). Pulmonary artery CT attenuation, signal-to-noise ratio, and contrast-to-noise-ratio were assessed as objective criteria of image quality, while subjective ratings of four radiologists were compared at 60 keV using virtual monoenergetic imaging and polychromatic standard reconstructions. Interrater reliability was determined by means of the intraclass correlation coefficient (ICC). Effective dose was compared between patient cohorts. RESULTS Subjective image quality was deemed superior by all four reviewers for 60-keV PCD scans (excellent or good ratings in 93.8% of PCD vs. 84.4% of 60 keV EID scans, ICC = 0.72). No examinations on either system were considered "non-diagnostic." Objective image quality parameters were significantly higher in the EID group (mostly p < 0.001), both in the polychromatic reconstructions and at 60 keV. The ED (1.4 vs. 3.3 mSv) was significantly lower in the PCD cohort (p < 0.001). CONCLUSIONS PCD-CTPA allows for considerable reduction of contrast medium and radiation dose in the diagnosis of acute pulmonary embolism, while maintaining good to excellent image quality compared to conventional EID-CTPA. CLINICAL RELEVANCE STATEMENT Clinical PCD-CT allows for spectral assessment of pulmonary vasculature with high scan speed, which is beneficial in patients with suspected pulmonary embolism, frequently presenting with dyspnea. Simultaneously PCD-CT enables substantial reduction of contrast medium and radiation dose. KEY POINTS • The clinical photon-counting detector CT scanner used in this study allows for high-pitch multi-energy acquisitions. • Photon-counting computed tomography allows for considerable reduction of contrast medium and radiation dose in the diagnosis of acute pulmonary embolism. • Subjective image quality was rated best for 60-keV photon-counting scans.
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Affiliation(s)
- Pauline Pannenbecker
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany.
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Philipp Gruschwitz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Theresa S Patzer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Andreas M Weng
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Julius F Heidenreich
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Thorsten A Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Bernhard Petritsch
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
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The influence of iterative reconstruction level on image quality and radiation dose in CT pulmonary angiography examinations. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2020.108989] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Association of Radiation Doses and Cancer Risks from CT Pulmonary Angiography Examinations in Relation to Body Diameter. Diagnostics (Basel) 2020; 10:diagnostics10090681. [PMID: 32917029 PMCID: PMC7554806 DOI: 10.3390/diagnostics10090681] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/18/2020] [Accepted: 08/18/2020] [Indexed: 01/02/2023] Open
Abstract
In this study, we aimed to estimate the probability of cancer risk induced by CT pulmonary angiography (CTPA) examinations concerning effective body diameter. One hundred patients who underwent CTPA examinations were recruited as subjects from a single institution in Kuala Lumpur. Subjects were categorized based on their effective diameter size, where 19–25, 25–28, and >28 cm categorized as Groups 1, 2, and 3, respectively. The mean value of the body diameter of the subjects was 26.82 ± 3.12 cm, with no significant differences found between male and female subjects. The risk of cancer in breast, lung, and liver organs was 0.009%, 0.007%, and 0.005% respectively. The volume-weighted CT dose index (CTDIvol) was underestimated, whereas the size-specific dose estimates (SSDEs) provided a more accurate description of the radiation dose and the risk of cancer. CTPA examinations are considered safe but it is essential to implement a protocol optimized following the As Low as Reasonably Achievable (ALARA) principle.
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Establishment of CTPA Local Diagnostic Reference Levels with Noise Magnitude as a Quality Indicator in a Tertiary Care Hospital. Diagnostics (Basel) 2020; 10:diagnostics10090680. [PMID: 32916913 PMCID: PMC7555305 DOI: 10.3390/diagnostics10090680] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/12/2020] [Accepted: 08/14/2020] [Indexed: 12/16/2022] Open
Abstract
This study aimed to establish the local diagnostic reference levels (LDRLs) of computed tomography pulmonary angiography (CTPA) examinations based on body size with regard to noise magnitude as a quality indicator. The records of 127 patients (55 males and 72 females) who had undergone CTPAs using a 128-slice CT scanner were retrieved. The dose information, scanning acquisition parameters, and patient demographics were recorded in standardized forms. The body size of patients was categorized into three groups based on their anteroposterior body length: P1 (14–19 cm), P2 (19–24 cm), and P3 (24–31 cm), and the radiation dose exposure was statistically compared. The image noise was determined quantitatively by measuring the standard deviation of the region of interest (ROI) at five different arteries—the ascending and descending aorta, pulmonary trunk, and the left and right main pulmonary arteries. We observed that the LDRL values were significantly different between body sizes (p < 0.05), and the median values of the CT dose index volume (CTDIvol) for P1, P2, and P3 were 6.13, 8.3, and 21.40 mGy, respectively. It was noted that the noise reference values were 23.78, 24.26, and 23.97 HU for P1, P2, and P3, respectively, which were not significantly different from each other (p > 0.05). The CTDIvol of 9 mGy and dose length product (DLP) of 329 mGy∙cm in this study were lower than those reported by other studies conducted elsewhere. This study successfully established the LDRLs of a local healthcare institution with the inclusion of the noise magnitude, which is comparable with other established references.
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Liu D, Cai X, Che X, Ma Y, Fu Y, Li L. Visibility and image quality of peripheral pulmonary arteries in pulmonary embolism patients using free-breathing combined with a high-threshold bolus-triggering technique in CT pulmonary angiography. J Int Med Res 2020; 48:300060520939326. [PMID: 32814489 PMCID: PMC7444127 DOI: 10.1177/0300060520939326] [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] [Indexed: 01/02/2023] Open
Abstract
Objective To investigate the visibility of peripheral pulmonary arteries by computed tomography pulmonary angiography (CTPA) and image quality using a free-breathing combined with a high-threshold bolus triggering technique and to explore the feasibility of this technique in pulmonary embolism (PE) patients who cannot hold their breath. Methods Patients with suspected PE who underwent CTPA (n=240) were randomly assigned to two groups: free-breathing (n=120) or breath-holding (n=120). Results The mean scanning time or visible pulmonary artery distal branches were not different between the groups. Mean CT main pulmonary artery (MPA) values, apical segment (S1), and posterior basal segment (S10) in the free-breathing group were higher compared with the breath-holding group. The subjective image quality score in the free-breathing group was higher compared with the breath-holding group. In the free-breathing group, no respiratory artifact was observed. In the breath-holding group, obvious respiratory artifacts were caused by severe chronic obstructive pulmonary disease (COPD), dyspnea, or other diseases that preclude patients from holding their breath. Conclusion The free-breathing mode CTPA combined with a high-threshold bolus triggering technique can provide high quality images with a lower incidence of respiratory and cardiac motion artifacts, which is especially valuable for patients who cannot hold their breath.
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Affiliation(s)
- Daliang Liu
- Department of Radiology, Liaocheng People's Hospital, Liaocheng, Shandong, P. R. China
| | - Xiansheng Cai
- Department of Radiology, Liaocheng People's Hospital, Liaocheng, Shandong, P. R. China
| | - Xiaoshuang Che
- Department of Radiology, Liaocheng People's Hospital, Liaocheng, Shandong, P. R. China
| | - Yong Ma
- Department of Radiology, Liaocheng People's Hospital, Liaocheng, Shandong, P. R. China
| | - Yucun Fu
- Department of Radiology, Liaocheng People's Hospital, Liaocheng, Shandong, P. R. China
| | - Lin Li
- Department of Radiology, Liaocheng People's Hospital, Liaocheng, Shandong, P. R. China
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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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Wu H, Chen X, Zhou H, Qin B, Cao J, Pan Z, Wang Z. An optimized test bolus for computed tomography pulmonary angiography and its application at 80 kV with 10 ml contrast agent. Sci Rep 2020; 10:10208. [PMID: 32576901 PMCID: PMC7311447 DOI: 10.1038/s41598-020-67145-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 05/04/2020] [Indexed: 01/31/2023] Open
Abstract
Computed tomography pulmonary angiography (CTPA) is usually used for pulmonary embolism (PE) detection. However, the determination of scan timing remains a challenge due to the short scan duration of CTPA. We aimed to develop an optimized test bolus to determine scan delay in CTPA. The time-enhancement curves were obtained by measuring the enhancement within a region of interest in the main pulmonary artery and vein. A total of 70 patients were randomly divided into two groups (n = 35 each): the control group underwent CTPA using the test bolus approach and the test group underwent CTPA using the biphasic time-enhancement curves approach. Tube voltages of 100 kVp and 80 kVp and 20 ml and 10 ml contrast agent were adopted in the control and test groups, respectively. The CT numbers, image quality, PE detection was evaluated. There was a point of intersection between the pulmonary artery and vein test bolus enhancement curves. The scan delay time (TDELAY) was obtained based on the time at intersection (TCROSS) and the scan duration (TSD): TDELAY = TCROSS − TSD. The mean CT numbers for pulmonary vein in the control were higher than those in the test group (all p < 0.001). The image quality for the pulmonary arteries in the test group was better than that in the control group (p < 0.01), with artifact reduction in the superior vena cava. Segmental PE could be detected using the optimized protocol. The radiation dose and iodine load in the test group were all lower than those in the control (p < 0.01). We established an approach to calculate the scan delay of CTPA, and this approach could be used for CTPA at 80 kVp with 10 ml contrast agent.
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Affiliation(s)
- Huiming Wu
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Xiao Chen
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Hao Zhou
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Bin Qin
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Jian Cao
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Zhaochun Pan
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Zhongqiu Wang
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China.
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11
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Tang S, Zhang G, Chen Z, Liu X, Fan X, Liu D, He L. Application of multiple injections of contrast agent in head and neck CT arteriovenous angiography in children: Study protocol clinical trial (SPIRIT Compliant). Medicine (Baltimore) 2020; 99:e19773. [PMID: 32282739 PMCID: PMC7220194 DOI: 10.1097/md.0000000000019773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE To investigate the application value of multiple injections of contrast agent in head and neck CT arteriovenous angiography in children. METHODS A total of 100 children aged 6 to 7 years who needed head and neck CT arteriovenous angiography were prospectively selected. They were randomly divided into a control group and a research group, with 50 children in each group. The same scanning parameters and reconstruction methods were used. The right median cubital vein was injected intravenously with the contrast agent Omnipaque (350 mg I/ml). For children in the control group, a bolus of undiluted contrast agent (dose was 2 ml/kg, upper limit was 50 ml) was injected 1 time. The arterial phase and vein phase of the head and neck vessels were scanned. For children in the research group, a contrast agent bolus diluted with saline to a concentration of 20% was first injected (dose was 1 ml/kg, upper limit was 25 ml), and then an undiluted contrast agent bolus (dose was 1 ml/kg, upper limit was 25 ml) was injected. Thresholds were used to trigger the scanning of the head and neck arterial phases. The CT image quality of the head and neck arteries and veins, radiation dose and contrast agent dose were compared between the 2 groups. RESULTS Subjective evaluation of CT image quality of arteries: there were 47 cases of 4 points and 3 cases of 3 points in the control group and 34 cases of 4 points and 16 cases of 3 points in the research group. Subjective evaluation of CT image quality of veins: there were 47 cases of 4 points and 3 cases of 3 points in the control group and 5 cases of 4 points, 42 cases of 3 points and 3 cases of 2 points in the research group. The CT value of brain arterial vessel enhancement was higher in the control group than the research group, and the difference was statistically significant (P < .05). The CT value of vein enhancement was higher in the control group than the research group, and the difference was statistically significant (P < .05). The X-ray dose in the research group was 51% lower than that in the control group; the contrast agent dose in the research group was 44% lower than that in the control group. CONCLUSION For the head and neck enhanced CT examination of children, the method of first bolus injection of 20% diluted contrast agent and later bolus injection of undiluted contrast agent can clearly demonstrate the head and neck arteries and veins one time, reducing the X-ray dose and contrast agent dose, which has clinical practical value in the enhanced CT examination of children with head and neck disease.
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Affiliation(s)
| | - Guanping Zhang
- National Clinical Research Center for Child Health and Disorders
| | - Zhuo Chen
- Department of Radiology
- Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Xianfan Liu
- Ministry of Education Key Laboratory of Child Development and Disorders
| | - Xiao Fan
- China International Science and Technology Cooperation base of Child development and Critical Disorders
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12
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Harun HH, Karim MKA, Abbas Z, Sabarudin A, Muniandy SC, Ibahim MJ. Effect of iterative reconstruction algorithm levels on noise index and figure-of-merit in CT pulmonary angiography examinations. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2020; 28:893-903. [PMID: 32741801 DOI: 10.3233/xst-200699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
PURPOSE To evaluate the influence of iterative reconstruction (IR) levels on Computed Tomography (CT) image quality and to establish Figure of Merit (FOM) value for CT Pulmonary Angiography (CTPA) examinations. METHODS Images of 31 adult patients who underwent CTPA examinations in our institution from March to April 2019 were retrospectively collected. Other data, such as scanning parameters, radiation dose and body habitus information from the subjects were also recorded. Six different levels of IR were applied to the volume data of the subjects. Five circles of the region of interest (ROI) were drawn in five different arteries namely, pulmonary trunk, right pulmonary artery, left pulmonary artery, ascending aorta and descending aorta. The mean Signal-to-noise ratio (SNR) was obtained, and the FOM was calculated in a fraction of the SNR2 divided by volume-weighted CT dose index (CTDIvol) and SNR2 divided by the size-specific dose estimates (SSDE). RESULTS Overall, we observed that the mean value of CTDIvol and SSDE were 13.79±7.72 mGy and 17.25±8.92 mGy, respectively. Notably, SNR values significantly increase with increase of the IR level (p < 0.05). There are also significant differences (p < 0.05) in the FOM for both SNR2/SSDE and SNR2/CTDIvol attained in different IR levels. CONCLUSION We successfully evaluate the value of radiation dose and image quality performance and set up a figure of merit for both parameters to further verify scanning protocols by radiology personnel.
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Affiliation(s)
- H H Harun
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - M K A Karim
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Z Abbas
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - A Sabarudin
- Department of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysiainstitution>
| | - S C Muniandy
- Department of Radiology, Hospital Kuala Lumpur, Jalan Pahang, Kuala Lumpur, Malaysia
| | - M J Ibahim
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh, Selangor, Malaysia
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High-pitch non-gated scans on the second and third generation dual-source CT scanners: comparison of coronary image quality. Clin Imaging 2020; 59:45-49. [DOI: 10.1016/j.clinimag.2019.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/29/2019] [Accepted: 09/23/2019] [Indexed: 11/24/2022]
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Radiation dose and image quality of high-pitch emergency abdominal CT in obese patients using third-generation dual-source CT (DSCT). Sci Rep 2019; 9:15877. [PMID: 31685902 PMCID: PMC6828752 DOI: 10.1038/s41598-019-52454-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 10/17/2019] [Indexed: 01/01/2023] Open
Abstract
In this third-generation dual-source CT (DSCT) study, we retrospectively investigated radiation dose and image quality of portal-venous high-pitch emergency CT in 60 patients (28 female, mean age 56 years) with a body mass index (BMI) ≥ 30 kg/m2. Patients were dichotomized in groups A (median BMI 31.5 kg/m2; n = 33) and B (36.8 kg/m2; n = 27). Volumetric CT dose index (CTDIvol), size-specific dose estimate (SSDE), dose length product (DLP) and effective dose (ED) were assessed. Contrast-to-noise ratio (CNR) and dose-independent figure-of-merit (FOM) CNR were calculated. Subjective image quality was assessed using a five-point scale. Mean values of CTDIvol, SSDE as well as normalized DLP and ED were 7.6 ± 1.8 mGy, 8.0 ± 1.8 mGy, 304 ± 74 mGy * cm and 5.2 ± 1.3 mSv for group A, and 12.6 ± 3.7 mGy, 11.0 ± 2.6 mGy, 521 ± 157 mGy * cm and 8.9 ± 2.7 mSv for group B (p < 0.001). CNR of the liver and spleen as well as each calculated FOM CNR were significantly higher in group A (p < 0.001). Subjective image quality was good in both groups. In conclusion, third-generation abdominal high-pitch emergency DSCT yields good image quality in obese patients. Radiation dose increases in patients with a BMI > 36.8 kg/m2.
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Lebedev S, Fournie E, Stierstorfer K, Kachelrieß M. Stack transition artifact removal (STAR) for cardiac CT. Med Phys 2019; 46:4777-4791. [PMID: 31444974 DOI: 10.1002/mp.13786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 06/12/2019] [Accepted: 07/03/2019] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION In cardiac computed tomography (CT), irregular motion may lead to unique artifacts for scanners with a longitudinal collimation that does not cover the entire heart. Given partial coverage, subvolumes, or stacks, may be reconstructed and used to assemble a final CT volume. Irregular motion, for example, due to cardiac arrhythmia or breathing, may cause mismatch between neighboring stacks and therefore discontinuities within the final CT volume. The aim of this work is the removal of the discontinuities that are hereafter referred to as stack transition artifacts. METHOD AND MATERIALS A stack transition artifact removal (STAR) is achieved using a symmetric deformable image registration. A symmetric Demons algorithm was implemented and applied to stacks to remove mismatch and therefore the stack transition artifacts. The registration can be controlled with one parameter that affects the smoothness of the deformation vector field (DVF). The latter is crucial for realistically transforming the stacks. Different smoothness settings as well as an entirely automatic parameter selection that considers the required deformation magnitude for each registration were tested with patient data. Thirteen datasets were evaluated. Simulations were performed on two additional datasets. RESULTS AND CONCLUSION STAR considerably improved image quality while computing realistic DVFs. Discontinuities, for example, appearing as breaks or cuts in coronary arteries or cardiac valves, were removed or considerably reduced. A constant smoothing parameter that ensured satisfactory results for all datasets was found. The automatic parameter selection was able to find a proper setting for each individual dataset. Consequently, no over regularization of the DVF occurred that would unnecessarily limit the registration accuracy for cases with small deformations. The automatic parameter selection yielded the best overall results and provided a registration method for cardiac data that does not require user input.
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Affiliation(s)
- Sergej Lebedev
- X-Ray Imaging and Computed Tomography, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany.,Siemens Healthineers, 91301, Forchheim, Germany.,Department of Physics and Astronomy, University of Heidelberg, 69120, Heidelberg, Germany
| | | | | | - Marc Kachelrieß
- X-Ray Imaging and Computed Tomography, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany.,Medical Faculty, University of Heidelberg, 69120, Heidelberg, Germany
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Al Hassan DA, Waheed KB, El Sirafy MN, Khattab MA, Al-Hammadi HI, Ibrahim MF, Arulanantham ZJ. Computed tomography pulmonary angiography using high-pitch dual-source scanner technology. Saudi Med J 2019; 40:230-237. [PMID: 30834417 PMCID: PMC6468199 DOI: 10.15537/smj.2019.3.23940] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Objectives: To compare use of ultra-fast high-pitch dual-source free-breathing computed tomography pulmonary angiogram (CTPA) with conventional standard-pitch single-source breath-hold CTPA. Methods: This retrospective comparative study was conducted in Radiology Department at King Fahad Military Medical Complex Dhahran, Saudi Arabia from July 2016 to December 2017. Patients (N=130) were divided into 2 groups, each having 65 consecutive patients; Group-1 (single-source CT) and Group-2 (dual-source CT). Previously treated pulmonary embolism cases, pregnant patients and those with incomplete data were excluded. Image quality was subjectively assessed by 2 readers for adequacy of contrast opacification and pulmonary vessel outline, and presence of artifacts (breathing motion, cardiac pulsation, and contrast related). Scan acquisition times and radiation doses were also compared. Chi-square and t-test were used to determine association. Results: Improved image quality (optimal studies without artifacts 91%) was seen in Group-2 compared to Group-1 (optimal studies without artifacts 75.4%). Also, reduced scan time (1-2 sec.) and radiation dose (mean dose length product (DLP)-248 mGy-cm) were observed in Group-2 compared to Group-1 (scan time- 6.5 sec, mean DLP-375). Results were found significant (p<0.05). Conclusion: High-pitch dual-source CT with free-breathing yields better image quality, reduces image acquisition time and radiation doses.
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Affiliation(s)
- Donya A Al Hassan
- Department of Radiology, King Fahad Military Medical Complex,Prince Sultan Military College of Health Science, Dhahran, Kingdom of Saudi Arabia. E-mail.
| | - Khawaja B Waheed
- Radiology Department, King Fahad Military Medical Complex, Dhahran, Kingdom of Saudi Arabia. E-mail.
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17
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Forbrig R, Geyer LL, Stahl R, Thorsteinsdottir J, Schichor C, Kreth FW, Patzig M, Herzberg M, Liebig T, Dorn F, Trumm CG. Radiation dose and image quality in intraoperative CT (iCT) angiography of the brain with stereotactic head frames. Eur Radiol 2019; 29:2859-2867. [PMID: 30635759 DOI: 10.1007/s00330-018-5930-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 11/06/2018] [Accepted: 11/28/2018] [Indexed: 01/04/2023]
Abstract
OBJECTIVES Intraoperative CT (iCT) angiography of the brain with stereotactic frames is an integral part of navigated neurosurgery. Validated data regarding radiation dose and image quality in these special examinations are not available. We therefore investigated two iCT protocols in this IRB-approved study. METHODS Retrospective analysis of patients, who received a cerebral stereotactic iCT angiography on a 128 slice CT scanner between February 2016 and December 2017. In group A, automated tube current modulation (ATCM; reference value 410 mAs) and automated tube voltage selection (reference value 120 kV) were enabled, and only examinations with a selected voltage of 120 kV were included. In group B, fixed parameters were applied (300 mAs, 120 kV). Radiation dose was measured by assessing the volumetric CT dose index (CTDIvol), dose length product (DLP) and effective dose (ED). Signal-to-noise ratio (SNR) and image noise were assessed for objective image quality, visibility of arteries and grey-white differentiation for subjective image quality. RESULTS Two hundred patients (n = 100 in each group) were included. In group A, median selected tube current was 643 mAs (group B, 300 mAs; p < 0.001). Median values of CTDIvol, DLP and ED were 91.54 mGy, 1561 mGy cm and 2.97 mSv in group A, and 43.15 mGy, 769 mGy cm and 1.46 mSv in group B (p < 0.001). Image quality did not significantly differ between groups (p > 0.05). CONCLUSIONS ATCM yielded disproportionally high radiation dose due to substantial tube current increase at the frame level, while image quality did not improve. Thus, ATCM should preferentially be disabled. KEY POINTS • Automated tube current modulation (ATCM) yields disproportionally high radiation dose in intraoperative CT angiography of the brain with stereotactic head frames. • ATCM does not improve overall image quality in these special examinations. • ATCM is not yet optimised for CT angiography of the brain with major extracorporeal foreign materials within the scan range.
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Affiliation(s)
- Robert Forbrig
- Institute of Neuroradiology, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany.
| | - Lucas L Geyer
- Center of Radiology and Neuroradiology, Klinikum Ingolstadt, Ingolstadt, Germany
| | - Robert Stahl
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany
| | | | - Christian Schichor
- Department of Neurosurgery, University Hospital, LMU Munich, Munich, Germany
| | | | - Maximilian Patzig
- Institute of Neuroradiology, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Moriz Herzberg
- Institute of Neuroradiology, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Thomas Liebig
- Institute of Neuroradiology, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Franziska Dorn
- Institute of Neuroradiology, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Christoph G Trumm
- Institute for Diagnostic and Interventional Radiology, Neuroradiology and Nuclear Medicine, Städtisches Klinikum München Harlaching, Munich, Germany
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Aldosari S, Jansen S, Sun Z. Patient-specific 3D printed pulmonary artery model with simulation of peripheral pulmonary embolism for developing optimal computed tomography pulmonary angiography protocols. Quant Imaging Med Surg 2019; 9:75-85. [PMID: 30788248 PMCID: PMC6351806 DOI: 10.21037/qims.2018.10.13] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/26/2018] [Indexed: 11/06/2022]
Abstract
BACKGROUND Computed tomography pulmonary angiography (CTPA) is the preferred imaging modality for diagnosis of patients with suspected pulmonary embolism (PE). Radiation dose associated with CTPA has been significantly reduced due to the use of dose-reduction strategies, however, investigation of low-dose CTPA with use of different kVp and pitch values has not been systematically studied. The aim of this study was to utilize a 3D printed pulmonary model with simulation of small thrombus in the pulmonary arteries for development of optimal CTPA protocols. METHODS Animal blood clots were inserted into the pulmonary arteries to simulate peripheral embolism based on a realistic 3D printed pulmonary artery model. The 3D printed model was scanned with 192-slice 3rd generation dual-source CT with 1 mm slice thickness and 0.5 mm reconstruction interval. All images were reconstructed with advanced modelled iterative reconstruction (IR) at a strength level of 3. CTPA scanning parameters were as follows: 70, 80, 100 and 120 kVp, 0.9, 2.2 and 3.2 pitch values. Quantitative assessment of image quality was determined by measuring signal-to-noise ratio (SNR) in both main pulmonary arteries, while qualitative analysis of images was scored by two experienced radiologists (score of 1 indicates poor visualization of thrombus with no confidence, and score of 5 excellent visualization of thrombus with high confidence) to determine the image quality in relation to different scanning protocols for detection of thrombus in the pulmonary arteries. RESULTS No significant differences were found in SNR measurements among all CTPA protocols (P>0.05), regardless of kVp or pitch values used, although SNR was higher with 120 kVp and 0.9 and 2.2 pitch protocols than that in other protocols. The thrombi were detected in all images, with 70 kVp and 3.2 pitch protocol scored the lowest with a score of 3 by two observers, and images with other protocols were scored 4 or 5. Lowering kVp from 120 to 70 with use of high-pitch 2.2 or 3.2 protocol resulted in up to 80% dose reduction without significantly affecting image quality. CONCLUSIONS Low-dose CT pulmonary angiography protocols comprising 70 kVp and high pitch 2.2 or 3.2 allow for detection of peripheral PE with significant reduction in radiation dose while images are still considered diagnostic.
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Affiliation(s)
- Sultan Aldosari
- Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, Perth, Australia
| | - Shirley Jansen
- Department of Vascular and Endovascular Surgery, Sir Charles Gairdner Hospital, Perth, Australia
- Curtin Medical School, Curtin University, Perth, Australia
- Faculty of Health and Medical Sciences, University of Western Australia, Crawley, Australia
- Heart and Vascular Research Institute, Harry Perkins Medical Research Institute, Perth, Australia
| | - Zhonghua Sun
- Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, Perth, Australia
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Aldosari S, Jansen S, Sun Z. Optimization of computed tomography pulmonary angiography protocols using 3D printed model with simulation of pulmonary embolism. Quant Imaging Med Surg 2019; 9:53-62. [PMID: 30788246 DOI: 10.21037/qims.2018.09.15] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Three-dimensional (3D) printing has been shown to accurately replicate anatomical structures and pathologies in complex cardiovascular disease. Application of 3D printed models to simulate pulmonary arteries and pulmonary embolism (PE) could assist development of computed tomography pulmonary angiography (CTPA) protocols with low radiation dose, however, this has not been studied in the literature. The aim of this study was to investigate optimal CTPA protocols for detection of PE based on a 3D printed pulmonary model. Methods A patient-specific 3D printed pulmonary artery model was generated with thrombus placed in both main pulmonary arteries to represent PE. The model was scanned with 128-slice dual-source CT with slice thickness of 1 and 0.5 mm reconstruction interval. The tube voltage was selected to range from 70, 80, 100 to 120 kVp, and pitch value from 0.9 to 2.2 and 3.2. Quantitative assessment of image quality in terms of signal-to-noise ratio (SNR) was measured in the main pulmonary arteries and within the thrombus regions to determine the relationship between image quality and scanning protocols. Both two-dimensional (2D) and 3D virtual intravascular endoscopy (VIE) images were generated to demonstrate pulmonary artery and thrombus appearances. Results PE was successfully simulated in the 3D printed pulmonary artery model. There were no significant differences in SNR measured in the main pulmonary arteries with 100 and 120 kVp CTPA protocols (P>0.05), regardless of pitch value used. SNR was significantly lower in the high-pitch 3.2 protocols when compared to other protocols using 70 and 80 kVp (P<0.05). There were no significant differences in SNR measured within the thrombus among the 100 and 120 kVp protocols (P>0.05). For low dose 70 and 80 kVp protocols, SNR was significantly lower in the high-pitch of 3.2 protocols than that in other protocols with different pitch values (P<0.01). 2D images showed the pulmonary arteries and thrombus clearly, while 3D VIE demonstrated intraluminal appearances of pulmonary wall and thrombus in all protocols, except for the 70 kVp and pitch 3.2 protocol, with visualization of thrombus and pulmonary artery wall affected by artifact associated with high image noise. Radiation dose was reduced by up to 80% when lowering kVp from 120 to 100 and 80 kVp with use of 3.2 high-pitch protocol, without significantly affecting image quality. Conclusions Low-dose CT pulmonary angiography can be achieved with use of low kVp (80 and 100) and high-pitch protocol with significant reduction in radiation dose while maintaining diagnostic images of PE. Use of high pitch, 3.2 in 70 kVp protocol should be avoided due to high image noise and poorer quality.
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Affiliation(s)
- Sultan Aldosari
- Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia
| | - Shirley Jansen
- Department of Vascular and Endovascular Surgery, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.,School of Public Health, Curtin University, Perth, Western Australia, Australia.,Faculty of Health and Medical Sciences, University of Western Australia, Crawley, Western Australia, Australia.,Heart and Vascular Research Institute, Harry Perkins Medical Research Institute, Perth, Western Australia, Australia
| | - Zhonghua Sun
- Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia
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Gariani J, Martin SP, Botsikas D, Becker CD, Montet X. Evaluating the effect of increased pitch, iterative reconstruction and dual source CT on dose reduction and image quality. Br J Radiol 2018; 91:20170443. [PMID: 29762055 PMCID: PMC6209470 DOI: 10.1259/bjr.20170443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Objective: To compare radiation dose and image quality of thoracoabdominal scans obtained with a high-pitch protocol (pitch 3.2) and iterative reconstruction (Sinogram Affirmed Iterative Reconstruction) in comparison to standard pitch reconstructed with filtered back projection (FBP) using dual source CT. Methods: 114 CT scans (Somatom Definition Flash, Siemens Healthineers, Erlangen, Germany), 39 thoracic scans, 54 thoracoabdominal scans and 21 abdominal scans were performed. Analysis of three protocols was undertaken; pitch of 1 reconstructed with FBP, pitch of 3.2 reconstructed with SAFIRE, pitch of 3.2 with stellar detectors reconstructed with SAFIRE. Objective and subjective image analysis were performed. Dose differences of the protocols used were compared. Results: Dose was reduced when comparing scans with a pitch of 1 reconstructed with FBP to high-pitch scans with a pitch of 3.2 reconstructed with SAFIRE with a reduction of volume CT dose index of 75% for thoracic scans, 64% for thoracoabdominal scans and 67% for abdominal scans. There was a further reduction after the implementation of stellar detectors reflected in a reduction of 36% of the dose–length product for thoracic scans. This was not at the detriment of image quality, contrast-to-noise ratio, signal-to-noise ratio and the qualitative image analysis revealed a superior image quality in the high-pitch protocols. Conclusion: The combination of a high pitch protocol with iterative reconstruction allows significant dose reduction in routine chest and abdominal scans whilst maintaining or improving diagnostic image quality, with a further reduction in thoracic scans with stellar detectors. Advances in knowledge: High pitch imaging with iterative reconstruction is a tool that can be used to reduce dose without sacrificing image quality.
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Affiliation(s)
- Joanna Gariani
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
| | - Steve P Martin
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
| | - Diomidis Botsikas
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
| | - Christoph D Becker
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
| | - Xavier Montet
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
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Virtual Monoenergetic Imaging and Iodine Perfusion Maps Improve Diagnostic Accuracy of Dual-Energy Computed Tomography Pulmonary Angiography With Suboptimal Contrast Attenuation. Invest Radiol 2017; 52:659-665. [DOI: 10.1097/rli.0000000000000387] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Chen Y, Zhang X, Xue H, Zhu Y, Wang Y, Li Y, Zhang Z, Jin Z. Head and neck angiography at 70 kVp with a third-generation dual-source CT system in patients: comparison with 100 kVp. Neuroradiology 2017; 59:1071-1081. [DOI: 10.1007/s00234-017-1901-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/01/2017] [Indexed: 11/30/2022]
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Effect of Noise-Optimized Monoenergetic Postprocessing on Diagnostic Accuracy for Detecting Incidental Pulmonary Embolism in Portal-Venous Phase Dual-Energy Computed Tomography. Invest Radiol 2017; 52:142-147. [DOI: 10.1097/rli.0000000000000319] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Dual Energy CT Pulmonary Angiography with 6g Iodine-A Propensity Score-Matched Study. PLoS One 2016; 11:e0167214. [PMID: 27907049 PMCID: PMC5132396 DOI: 10.1371/journal.pone.0167214] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 11/10/2016] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To evaluate the performance of low contrast media (CM) dose dual-energy computed tomography pulmonary angiography (CTPA) with advanced monoenergetic reconstructions in patients with suspected pulmonary embolism (PE). MATERIALS AND METHODS The study had institutional review board approval; all patients gave written informed consent. Forty-one patients (25 men, 16 women, mean age 62.9±14.7 years) undergoing low CM dose (15ml, 6g iodine) dual-energy CTPA with advanced monoenergetic reconstructions were matched via propensity-scoring based on logistic regression analysis with a comparison group of 41 patients (24 men, 17 women, mean age 62.7±13.9 years) undergoing standard CM dose single-energy CTPA (80ml, 24g iodine). Subjective (noise, artifacts) and objective (attenuation, noise, contrast-to-noise ratio (CNR)) image quality was assessed by two blinded, independent readers. All patients underwent clinical follow-up after three months for evaluation of adverse events. RESULTS Interrater agreement for subjective image quality in both groups ranged from fair to excellent (ICC: 0.46-0.84); agreement for objective image quality was excellent (ICC: 0.83-0.93). There was no significant difference regarding subjective noise (p = 0.15-0.72) and artifacts (p = 0.16-1) between the low and the standard CM dose group. There was no significant difference regarding CNR between the CM dose groups (p = 0.11-0.87). Seven of the 41 (17%) patients in the low and 5/41 (12%) in the standard CM dose group were diagnosed with PE (p = 0.32). No patient suffered from subsequent PE or PE-associated death during the follow-up period. CONCLUSION Dual-energy CTPA with advanced monoenergetic reconstruction is feasible with 6g iodine and allows for the diagnosis and safe exclusion of central, lobar, and segmental PE.
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Martini K, Meier A, Higashigaito K, Saltybaeva N, Alkadhi H, Frauenfelder T. Prospective Randomized Comparison of High-pitch CT at 80 kVp Under Free Breathing with Standard-pitch CT at 100 kVp Under Breath-Hold for Detection of Pulmonary Embolism. Acad Radiol 2016; 23:1335-1341. [PMID: 27639625 DOI: 10.1016/j.acra.2016.07.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 07/18/2016] [Accepted: 07/19/2016] [Indexed: 12/11/2022]
Abstract
RATIONALE AND OBJECTIVES To prospectively compare high-pitch computed tomography (HPCT) under free breathing (FB) with standard-pitch CT (SPCT) under breath-hold (BH) for detection of pulmonary embolism (PE). MATERIALS AND METHODS One hundred consecutive patients (47 females; mean age 58.7 ± 16.6) randomly underwent HPCT-FB (n = 50) or SPCT-BH (n = 50). Radiation doses were documented. One reader measured pulmonary artery attenuation and noise; mean signal-to-noise ratio (SNR) was calculated. Two readers assessed image quality, diagnostic confidence for detection of PE, motion artifacts, assessability of anatomical structures, and presence of transient interruption of contrast as sign of Valsalva maneuver. Inter-reader agreement was calculated. RESULTS Radiation dose was significantly lower in HPCT compared to SPCT (2.68 ± 0.60 mGy vs 6.01 ± 2.26 mGy; P < .001). Mean pulmonary artery attenuation and image noise were significantly higher in HPCT (attenuation: 479 Hounsfield unit (HU) vs 343HU; P < .001; noise: 16 HU vs 10 HU; P < .001) whereas SNR was similar between groups (34 HU vs 38 HU; P = .258). HPCT had significantly higher diagnostic confidence for PE detection (P = .048), less cardiac and breathing artifacts (P < .001), better assessability of anatomical structures, and fewer cases of transient interruption of contrast (P < .001) compared to the SPCT. CONCLUSIONS HPCT-FB allows for a significant reduction of breathing and motion artifacts compared to SPCT-BH. Diagnostic confidence, assessability of vascular and bronchial structures, as well as SNR are maintained.
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Affiliation(s)
- K Martini
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland.
| | - A Meier
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland
| | - K Higashigaito
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland
| | - N Saltybaeva
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland
| | - H Alkadhi
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland
| | - T Frauenfelder
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland
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