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Kuramochi K, Sakashita T, Ogawa Y. [Usefulness of Delay Time Setting in Computed Tomography Pulmonary Angiography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2024; 80:539-546. [PMID: 38538314 DOI: 10.6009/jjrt.2024-1385] [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: 05/21/2024]
Abstract
PURPOSE During computed tomography pulmonary angiography (CTPA), a decrease in the CT value of the pulmonary artery may be observed due to poor contrast enhancement, even though the imaging is performed at the optimum timing while continuously injecting a contrast medium. This study focused on the increase in blood flow in the superior and inferior vena cava during inspiration that affects the decrease in the CT value of the pulmonary artery and investigated a radiography method in which a delay time was set after inspiration in clinical cases. METHODS A total of 50 patients who underwent CTPA for suspected pulmonary thromboembolism were included. Using the bolus tracking method, we monitored the pulmonary arteries before and after inspiration, and investigated the CT value changes. RESULTS A decrease in the CT value of the pulmonary artery after inspiration was observed in approximately 30% of cases. By setting the delay time, the contrast enhancement effect before and after inspiration became equivalent. CONCLUSION As a result of this study, avoiding a decrease in the CT value of the pulmonary artery is possible by setting a delay time after inspiration, which is considered useful during CTPA.
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Affiliation(s)
- Kenji Kuramochi
- Imaging Center, St. Marianna University School of Medicine Hospital
| | - Taichi Sakashita
- Imaging Center, St. Marianna University School of Medicine Hospital
| | - Yasuyoshi Ogawa
- Imaging Center, St. Marianna University School of Medicine Hospital
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Elameer M, Harris MV, Cox J. Diagnosis of venous thromboembolism in pregnancy: a review of current guidelines. Clin Radiol 2022; 77:904-912. [PMID: 36123200 DOI: 10.1016/j.crad.2022.08.122] [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] [Received: 10/11/2021] [Revised: 06/25/2022] [Accepted: 08/03/2022] [Indexed: 11/20/2022]
Abstract
Venous thromboembolic disease (VTE) is the leading cause of maternal death throughout the developed world. International and national guidance for the diagnosis and management of VTE in pregnancy is varied and limited, which can result in problems in clinical practice. The imaging challenges of VTE in the general population are challenging but become more complex in pregnancy due to the physiological changes in the circulatory system, which alter clinical judgment and test performance. As an additional factor, the relative radiation risks to the mother and fetus arising from diagnostic tests need to be assessed and communicated to the patient in a clear and understandable way. The purpose of this review is fourfold. We propose to review and summarise the current imaging guidelines available for this condition; critically review the evidence base within the current literature; address the issues of test performance of imaging examinations used for VTE in pregnancy; and address the question of radiation risk and how to communicate this information to patients.
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Affiliation(s)
- M Elameer
- Department of Neuroradiology, Royal Victoria Infirmary, Queen Victoria Road, Newcastle-upon-Tyne NE1 4LP, UK
| | - M V Harris
- Department of Radiology, Sunderland Royal Hospital, Kayll Road, Sunderland, SR4 7TP, UK
| | - J Cox
- Department of Radiology, Sunderland Royal Hospital, Kayll Road, Sunderland, SR4 7TP, UK.
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Tan S, Hamarati LB, Rajiah PS, Le Gal G, Ko JP, Stojanovska J. CTA of Acute Pulmonary Embolism: Best Practices. Semin Roentgenol 2022; 57:313-323. [DOI: 10.1053/j.ro.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/15/2022] [Accepted: 08/19/2022] [Indexed: 11/11/2022]
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Degerstedt SG, Winant AJ, Lee EY. Pediatric Pulmonary Embolism: Imaging Guidelines and Recommendations. Radiol Clin North Am 2021; 60:69-82. [PMID: 34836567 DOI: 10.1016/j.rcl.2021.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In contrast with the algorithms and screening criteria available for adults with suspected pulmonary embolism, there is a paucity of guidance on the diagnostic approach for children. The incidence of pulmonary embolism in the pediatric population and young adults is higher than thought, and there is an urgent need for updated guidelines for the imaging approach to diagnosis in the pediatric population. This article presents an up-to-date review of imaging techniques, characteristic radiologic findings, and an evidence-based algorithm for the detection of pediatric pulmonary embolism to improve the care of pediatric patients with suspected pulmonary embolism.
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Affiliation(s)
- Spencer G Degerstedt
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Abbey J Winant
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Edward Y Lee
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
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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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Choen S, Kim K, Kang K, Kang J, Nam J, Yoon J, Choi M. Effects of airway pressure on contrast enhancement and diameter of the pulmonary artery in healthy dogs as determined by use of computed tomography angiography. Am J Vet Res 2019; 80:756-763. [PMID: 31339762 DOI: 10.2460/ajvr.80.8.756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate effects of airway pressure on contrast enhancement and diameter of the pulmonary artery and determine the optimal airway pressure for pulmonary CT angiography in dogs. ANIMALS 8 healthy Beagles. PROCEDURES Thoracic CT was performed at end-expiration (0 cm H2O) and 2 positive-pressure end-inspirations (10 and 20 cm H2O). Attenuation curves of enhancement for the sinus of the pulmonary trunk artery were obtained by use of a bolus technique. Contrast medium (300 mg of I/kg) was administered IV, and CT imaging began at the time of peak enhancement. At each pressure, time to peak enhancement, ratio of blood flow from the caudal vena cava to the right side of the heart (KCdVC), and enhancement characteristics and diameter changes of the pulmonary artery were evaluated. RESULTS All dogs had a significant delay for time to peak enhancement in the sinus of the pulmonary trunk artery as airway pressure increased. The KCdVC progressively increased as airway pressure increased, and there was low contrast enhancement and increased pulmonary artery filling defects at 20 cm H2O. All pulmonary arteries had marked increases in diameter as pressure increased. Arterial distensibility in the gravity-dependent cranial lung region was greater than that in the gravity-independent caudal lung region at the 2 positive-pressure end-inspirations. CONCLUSIONS AND CLINICAL RELEVANCE Airway pressure affected time to peak enhancement, KCdVC, contrast enhancement, and pulmonary artery diameter. Results suggested that 10 cm H2O could be an optimal pressure for evaluation of the pulmonary artery of dogs by use of CT angiography. (Am J Vet Res 2019;80;756-763).
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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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Incidence of transient interruption of contrast (TIC) - A retrospective single-centre analysis in CT pulmonary angiography exams acquired during inspiratory breath-hold with the breathing command: "Please inspire gently!". PLoS One 2019; 14:e0210473. [PMID: 30653548 PMCID: PMC6336366 DOI: 10.1371/journal.pone.0210473] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 12/24/2018] [Indexed: 11/29/2022] Open
Abstract
Objectives To assess the occurrence of transient interruption of contrast (TIC) phenomenon in pulmonary computed tomography angiography (CTPA) exams performed in inspiratory breath-hold after patients were told to inspire gently. Methods In this retrospective single-centre study, CTPA exams of 225 consecutive patients scanned on a 16-slice CT scanner system were analysed. A-priori to measurements, exams were screened for inadequate pulmonary artery contrast due to incorrect bolus tracking or failure of i.v. contrast administration. Those exams were excluded. Attenuation values in the thoracic aorta and in the pulmonary trunk were assessed in duplicate measurements (M1 and M2) and the aorto-pulmonary density ratio was calculated. An aorto-pulmonary ratio > 1 with still contrast inflow being visible within the superior vena cava was defined as TIC. Results 3 patients were excluded due to incorrect bolus tracking. Final analysis was performed in 222 patients (mean age 65 ± 19 years, range 18 to 99 years). Mean density in the pulmonary trunk was 275±17 HU, in the aorta 208 ± 15 HU. Mean aorto-pulmonary ratio was 0.81± 0.29. 48 patients (21.6%) had an aorto-pulmonary ratio >1. Correlation of mean aorto-pulmonary ratio and age was: -0.213 (p = 0.001). Age was not significantly different for an aorto-pulmonary ratio >1 vs. ≤1 (p = 0.122). Both in M1 and M2, 33/222 patients presented with absolute HU values of < 200 HU within the pulmonary artery. In M1 measurements, 24 of these 33 patients (72%) fulfilled TIC criteria (M2: 25/33 patients (75%)). Conclusions TIC is a common phenomenon in CTPA studies with inspiratory breath-hold commands after patients were told to inspire gently with an incidence of 22% in our retrospective cohort. Occurrence of TIC shows a significant negative correlation with increasing age and disproportionately often occurs in patients with lower absolute contrast density values within their pulmonary arteries.
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Damm R, Mohnike K, Gazis A, Rogits B, Seidensticker M, Ricke J, Pech M. Improvement of Contrast Media Enhancement in CTA Evaluating Pulmonary Embolism by Utilizing 'Delayed' Bolus Tracking in the Descending Aorta. Pol J Radiol 2016; 81:422-7. [PMID: 27668026 PMCID: PMC5022633 DOI: 10.12659/pjr.897456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 01/31/2016] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND As standard bolus triggering in the pulmonary trunk sometimes fails to achieve sufficient enhancement in the pulmonary arteries, the study investigates an alternative, 'delayed' position of the tracking ROI in the descending aorta. MATERIAL/METHODS Retrospective analysis of 143 patients suspected of pulmonary embolism investigated with 3 different scanners (16 to 80 rows) in clinical routine. Bolus triggering with 120 hounsfield units (HU) was performed using the pulmonary trunk (n=70) or descending aorta (n=73) after application of 70 to 120 mL of contrast agent, Iomeprol 300. Student's t-test was applied to compare vascular enhancement. Additional factors were analysed by a regression analysis. RESULTS Positioning of the tracking ROI in the descending aorta achieved a significantly higher contrast enhancement in the pulmonary trunk with a mean increase of 63 HU (p<0.001). CONCLUSIONS In CTA, delayed acquisition by using the descending aorta for bolus triggering can improve the enhancement of the pulmonary trunk to investigate a pulmonary embolism. Furthermore, the scan protocol simultaneously allows to rule out aortic pathologies as an alternative cause for a similar clinical condition.
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Affiliation(s)
- Robert Damm
- Department for Radiology and Nuclear Medicine, University of Magdeburg, Magdeburg, Germany
| | - Konrad Mohnike
- Department for Radiology and Nuclear Medicine, University of Magdeburg, Magdeburg, Germany
| | - Angelos Gazis
- Department for Radiology and Nuclear Medicine, University of Magdeburg, Magdeburg, Germany
| | - Bela Rogits
- Department for Radiology and Nuclear Medicine, University of Magdeburg, Magdeburg, Germany
| | - Max Seidensticker
- Department for Radiology and Nuclear Medicine, University of Magdeburg, Magdeburg, Germany
| | - Jens Ricke
- Department for Radiology and Nuclear Medicine, University of Magdeburg, Magdeburg, Germany
| | - Maciej Pech
- Department for Radiology and Nuclear Medicine, University of Magdeburg, Magdeburg, Germany
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High-pitch Helical Dual-source Computed Tomographic Pulmonary Angiography: Comparing Image Quality in Inspiratory Breath-hold and During Free Breathing. J Thorac Imaging 2016; 31:56-62. [PMID: 26447868 DOI: 10.1097/rti.0000000000000173] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of this study was to compare qualitative and quantitative image parameters of dual-source high-pitch helical computed tomographic pulmonary angiography (CTPA) in breath-holding (BH) versus free-breathing (FB) patients. MATERIALS AND METHODS Ninety-nine consented patients (61 female individuals; mean age±SD, 49±18.7 y) were randomized into BH (n=45) versus FB (n=54) high-pitch helical CTPA. Patient characteristics and CTPA radiation doses were analyzed. Two readers assessed for pulmonary embolism (PE), transient interruption of contrast, and respiratory and cardiac motion. The readers used a subjective 3-point scale to rate the pulmonary artery opacification and lung parenchymal appearance. A single reader assessed mean pulmonary artery signal intensity, noise, contrast, signal to noise ratio, and contrast to noise ratio. RESULTS PE was diagnosed in 16% BH and 19% FB patients. CTPAs of both groups were of excellent or acceptable quality for PE evaluation and of similar mean radiation doses (1.3 mSv). Transient interruption of contrast was seen in 5/45 (11%) BH and 5/54 (9%) FB patients (not statistically significant, P=0.54). No statistically significant difference was noted in cardiac, diaphragmatic, and lung parenchymal motion. Lung parenchymal assessment was excellent in all cases, except for 5/54 (9%) motion-affected FB cases with acceptable quality (statistically significant, P=0.03). No CTPA was considered nondiagnostic by any of the readers. No objective image quality differences were noted between both groups (P>0.05). CONCLUSIONS High-pitch helical CTPA acquired during BH or in FB yields comparable image quality for the diagnosis of PE and lung pathology, with low radiation exposure. Only a modest increase in lung parenchymal artifacts is encountered in FB high-pitch helical CTPA.
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Thacker PG, Lee EY. Advances in Multidetector CT Diagnosis of Pediatric Pulmonary Thromboembolism. Korean J Radiol 2016; 17:198-208. [PMID: 26957904 PMCID: PMC4781758 DOI: 10.3348/kjr.2016.17.2.198] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/18/2015] [Indexed: 11/19/2022] Open
Abstract
Although pediatric pulmonary thromboembolism is historically believed to be rare with relatively little information available in the medical literature regarding its imaging evaluation, it is more common than previously thought. Thus, it is imperative for radiologists to be aware of the most recent advances in its imaging information, particularly multidetector computed tomography (MDCT), the imaging modality of choice in the pediatric population. The overarching goal of this article is to review the most recent updates on MDCT diagnosis of pediatric pulmonary thromboembolism.
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Affiliation(s)
- Paul G Thacker
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Edward Y Lee
- Division of Thoracic Imaging, Department of Radiology and Medicine, Pulmonary Division Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Influence of Respiratory Position on Contrast Attenuation in Pulmonary CT Angiography: A Prospective Randomized Clinical Trial. AJR Am J Roentgenol 2016; 206:481-6. [DOI: 10.2214/ajr.15.15176] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Hinrichs JB, von Falck C, Hoeper MM, Olsson KM, Wacker FK, Meyer BC, Renne J. Pulmonary Artery Imaging in Patients with Chronic Thromboembolic Pulmonary Hypertension: Comparison of Cone-Beam CT and 64-Row Multidetector CT. J Vasc Interv Radiol 2016; 27:361-8.e2. [PMID: 26803575 DOI: 10.1016/j.jvir.2015.11.046] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 11/16/2015] [Accepted: 11/19/2015] [Indexed: 12/30/2022] Open
Abstract
PURPOSE To compare the depiction of pulmonary arteries in pulmonary arterial catheter-based contrast-enhanced cone-beam CT with peripheral intravenous contrast-enhanced multidetector CT in patients with suspected chronic thromboembolic pulmonary hypertension. MATERIAL AND METHODS In 20 patients (15 men and 5 women, 63.4 y ± 16.3), cone-beam CT using a catheter placed in the main pulmonary artery and 64-row multidetector CT using an appropriate venous access were performed. Contrast enhancement was measured in the main pulmonary artery, the right and left pulmonary arteries, and the left atrium. The amount of peripheral vessel conspicuity adjacent to the pleural surface (distance from vessel-to pleura) was measured. Two readers (R1, R2) independently evaluated the pulmonary arteries for image quality and pathologic findings in both modalities. RESULTS Contrast density was higher in the main pulmonary artery and right and left pulmonary arteries (P < .002) and lower in the left atrium (P = .001) on cone-beam CT. The smallest distance between clearly delineated vessels and the pleura was significantly lower on cone-beam CT images (P < .0001). Interobserver agreement was good for cone-beam CT (κ = 0.79) and multidetector CT (κ = 0.78), whereas intermodality agreement was moderate (R1, κ = 0.60; R2, κ = 0.59). Both readers detected more weblike stenoses with cone-beam CT (76; 22%) compared with multidetector CT (25; 7%). CONCLUSIONS Cone-beam CT shows improved contrast between pulmonary arteries and the left atrium and allows a more detailed depiction of the pulmonary arteries.
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Affiliation(s)
- Jan B Hinrichs
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany.
| | - Christian von Falck
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Marius M Hoeper
- Clinic for Pneumology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Karen M Olsson
- Clinic for Pneumology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Frank K Wacker
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Bernhard C Meyer
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Julius Renne
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
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Optimizing computed tomography pulmonary angiography using right atrium bolus monitoring combined with spontaneous respiration. Eur Radiol 2015; 25:2541-6. [PMID: 25850891 DOI: 10.1007/s00330-015-3664-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 02/01/2015] [Accepted: 02/12/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVES CT pulmonary angiography (CTPA) aims to provide pulmonary arterial opacification in the absence of significant pulmonary venous filling. This requires accurate timing of the imaging acquisition to ensure synchronization with the peak pulmonary artery contrast concentration. This study was designed to test the utility of right atrium (RA) monitoring in ensuring optimal timing of CTPA acquisition. METHODS Sixty patients referred for CTPA were divided into two groups. Group A (n = 30): CTPA was performed using bolus triggering from the pulmonary trunk, suspended respiration and 70 ml of contrast agent (CA). Group B (n = 30): CTPA image acquisition was triggered using RA monitoring with spontaneous respiration and 40 ml of CA. Image quality was compared. RESULTS Subjective image quality, average CT values of pulmonary arteries and density difference between artery and vein pairs were significantly higher whereas CT values of pulmonary veins were significantly lower in group B (all P < 0.05). There was no significant difference between the groups in the proportion of subjects where sixth grade pulmonary arteries were opacified (P > 0.05). CONCLUSIONS RA monitoring combined with spontaneous respiration to trigger image acquisition in CTPA produces optimal contrast enhancement in pulmonary arterial structures with minimal venous filling even with reduced doses of CA. KEY POINTS • Bolus tracking (BT) with pulmonary trunk monitoring is widely used in CTPA. • Pulmonary venous contamination is a disadvantage of BT due to transition delay time. • Right atrium monitoring with spontaneous respiration can optimize CTPA. • It produces optimal contrast enhancement in pulmonary arteries with minimal venous filling. • The contrast dose was significantly reduced.
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Pediatric CT quality management and improvement program. Pediatr Radiol 2014; 44 Suppl 3:519-24. [PMID: 25304715 DOI: 10.1007/s00247-014-3039-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 04/20/2014] [Accepted: 05/07/2014] [Indexed: 10/24/2022]
Abstract
Modern CT is a powerful yet increasingly complex technology that continues to rapidly evolve; optimal clinical implementation as well as appropriate quality management and improvement in CT are challenging but attainable. This article outlines the organizational structure on which a CT quality management and improvement program can be built, followed by a discussion of common as well as pediatric-specific challenges. Organizational elements of a CT quality management and improvement program include the formulation of clear objectives; definition of the roles and responsibilities of key personnel; implementation of a technologist training, coaching and feedback program; and use of an efficient and accurate monitoring system. Key personnel and roles include a radiologist as the CT director, a qualified CT medical physicist, as well as technologists with specific responsibilities and adequate time dedicated to operation management, CT protocol management and CT technologist education. Common challenges in managing a clinical CT operation are related to the complexity of newly introduced technology, of training and communication and of performance monitoring. Challenges specific to pediatric patients include the importance of including patient size in protocol and dose considerations, a lower tolerance for error in these patients, and a smaller sample size from which to learn and improve.
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