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Atalay M, Walle N, Grand D, Mayo-Smith W, Cronan J, Egglin T. Scan length optimization for pulmonary embolism at CT angiography: analysis based on the three-dimensional spatial distribution of 370 emboli in 100 patients. Clin Radiol 2011; 66:405-11. [DOI: 10.1016/j.crad.2010.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2010] [Revised: 10/20/2010] [Accepted: 11/02/2010] [Indexed: 11/17/2022]
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302
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Yang GF, Yang X, Zhang LJ, Zhu H, Chai X, Hu XB, Hu YX, Lu GM. Pulmonary enhancement imaging with dual energy CT for the detection of pulmonary embolism in a rabbit model: comparison to perfusion planar scintigraphy, SPECT and SPECT-CT modalities. Acad Radiol 2011; 18:605-14. [PMID: 21474059 DOI: 10.1016/j.acra.2010.12.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Revised: 11/29/2010] [Accepted: 12/11/2010] [Indexed: 10/18/2022]
Abstract
RATIONALE AND OBJECTIVES Pulmonary enhancement imaging (PEI) derived from dual-energy computed tomographic (CT) imaging has been used to detect perfusion defects from pulmonary embolism (PE). The purpose of this study was to compare the ability of PEI, planar, single photon-emission CT (SPECT) perfusion scintigraphy, and SPECT-CT fusion images to detect perfusion defect in a PE rabbit model. MATERIALS AND METHODS A PE model was made by injecting Gelfoam into the femoral veins of rabbits (n = 16). After 2 hours, 16 experimental rabbits and three control rabbits underwent contrast-enhanced dual-energy CT scans, from which PEI and CT pulmonary angiography were created, and planar, SPECT, and SPECT-CT fusion images were then obtained and evaluated. Pathologic determination of locations and numbers of lung lobes with PE were recorded. The sensitivity and specificity of the above-mentioned modalities were calculated using the histopathologic results as reference standards. RESULTS Emboli were present in 31 pulmonary lobes and absent in 64 lung lobes in histopathologic analysis. With the histopathologic findings as the gold standard, sensitivities and specificities of PEI, planar, SPECT, and SPECT-CT fusion images to detect PE were 100% and 96.9%, 71.0% and 84.4%, 77.4% and 90.6%, and 74.2% and 93.8%, respectively. McNemar's tests showed that PEI had higher diagnostic accuracy for the detection of PE than three scintigraphic images (all P values < .05), while three scintigraphic images had similar diagnostic accuracy (all P values = NS). CONCLUSIONS This study demonstrates that PEI from dual-energy CT imaging can provide higher diagnostic accuracy for detecting PE than planar, SPECT, and SPECT-CT fusion images in a rabbit model.
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Jung JI, Kim KJ, Ahn MI, Kim HR, Park HJ, Jung S, Lim HW, Park SH. Detection of pulmonary embolism using 64-slice multidetector-row computed tomography: accuracy and reproducibility on different image reconstruction parameters. Acta Radiol 2011; 52:417-21. [PMID: 21498315 DOI: 10.1258/ar.2011.100217] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Direct comparison of different image reconstruction parameters to detect pulmonary embolism (PE) using 64-slice multidetector-row computed tomography (MDCT) is absent and the most accurate image reconstruction parameters have not yet been proven. PURPOSE To compare different image reconstruction parameters for detecting PE using 64-slice MDCT in patients suspected of having an acute PE. MATERIAL AND METHODS Forty patients who underwent pulmonary CT angiography with 64-slice MDCT for a suspected PE were included. Different image reconstruction parameters were used for each patient: axial and coronal images with slice thicknesses of 0.625 mm, 1.3 mm, and 2.5 mm and axial maximum intensity projection (MIP) images with slab thicknesses of 1.3 mm, 2.5 mm, and 5 mm. Four experienced radiologists reviewed the images. The diagnosis of a PE was based on consensus review of axial 0.625 mm slice thickness images by two chest radiologists with allowing multiplanar reconstruction. Accuracy and reproducibility (kappa value) were evaluated. RESULTS In 15 of 40 patients, a PE was diagnosed. For detecting lobar PEs, axial images with a slice thickness of 1.25 mm and all coronal re-formatted images showed comparable results to axial images with a slice thickness of 0.625 mm. For detecting segmental PEs, axial images with a slice thickness of 1.25 mm and coronal images with a slice thickness of 0.625 mm re-formatted images showed comparable results to axial images of a slice thickness of 0.625 mm. For detecting subsegmental PEs, axial images with a slice thickness of 0.625 mm showed the highest sensitivity. Better reproducibility was obtained when the thinner slice thickness reconstructions were in axial and coronal images. However, reproducibility of MIP images with slab thicknesses of 2.5 mm and 5 mm was similar for detecting segmental and subsegmental PEs. CONCLUSION Thin-slice reconstruction of less than 1 mm is mandatory for visualization of PE at the subsegmental level.
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Affiliation(s)
- Jung Im Jung
- Department of Radiology, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea
| | - Ki Jun Kim
- Deparment of Radiology, Incheon St Mary's Hospital, College of Medicine, The Catholic University of Korea
| | - Myeong Im Ahn
- Department of Radiology, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea
| | - Hyo Rim Kim
- Deparment of Radiology, Yeouido St Mary's Hospital, College of Medicine, The Catholic University of Korea
| | - Hyun Jin Park
- Department of Radiology, St Vincent Hospital, College of Medicine, The Catholic University of Korea
| | - SeungHee Jung
- Deparment of Preventive Medicine, College of Medicine, The Catholic University of Korea, Korea
| | - Hyeon Woo Lim
- Deparment of Preventive Medicine, College of Medicine, The Catholic University of Korea, Korea
| | - Seog Hee Park
- Department of Radiology, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea
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304
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Dual energy CT pulmonary blood volume assessment in acute pulmonary embolism – correlation with D-dimer level, right heart strain and clinical outcome. Eur Radiol 2011; 21:1914-21. [DOI: 10.1007/s00330-011-2135-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 03/21/2011] [Accepted: 03/29/2011] [Indexed: 10/18/2022]
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305
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Cardiothoracic CT angiography: current contrast medium delivery strategies. AJR Am J Roentgenol 2011; 196:W260-72. [PMID: 21343473 DOI: 10.2214/ajr.10.5814] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Over the last decade, rapid technologic evolution in CT has resulted in improved spatial and temporal resolution and acquisition speed, enabling cardiothoracic CT angiography to become a viable and effective noninvasive alternative in the diagnostic algorithm. These new technologic advances have imposed new challenges for the optimization of contrast medium delivery and image acquisition strategies. CONCLUSION Thorough understanding of contrast medium dynamics is essential for the design of effective acquisition and injection protocols. This article provides an overview of the fundamentals affecting contrast enhancement, emphasizing the modifications to contrast material delivery protocols required to optimize cardiothoracic CT angiography.
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306
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Abstract
OBJECTIVE The purpose of this article is to discuss the diagnostic role of pulmonary CT angiography (CTA) in the workup of pulmonary embolism (PE), including specific populations, and issues such as pulmonary CTA combined with indirect CT venography; radiation dose considerations; the management of isolated subsegmental PE; and new technologic developments, such as dual-source/dual-energy pulmonary CTA. CONCLUSION The role of pulmonary CTA will continue to grow with the emergence of MDCT and dual-energy CT and their improved capabilities. However, the need for any given CT examination should always be justified on the basis of the individual patient's benefits and risks.
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307
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Accuracy and reproducibility of blood clot burden quantification with pulmonary CT angiography. AJR Am J Roentgenol 2011; 196:516-23. [PMID: 21343492 DOI: 10.2214/ajr.10.4603] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The purpose of our study was to assess the accuracy and reproducibility of clot burden quantification with pulmonary CT angiography (CTA). MATERIALS AND METHODS A semiautomated program was developed for segmentation and volumetric quantification of pulmonary embolus with pulmonary CTA. The accuracy of this measurement method was assessed using two pulmonary embolus phantoms. Reproducibility of the measurement method was assessed using clinical pulmonary CTA in 30 patients (16 women, 14 men; mean age, 62 years) with pulmonary embolism (PE). Two observers segmented and measured the volume of blood clot from pulmonary CTA images twice at two separate sessions. Accuracy was evaluated by the relative volume measurement error. Intra- and interobserver reliability were evaluated using intraclass correlation coefficient (ICC); agreement between measurements within and between the two observers was assessed using Bland-Altman analysis. RESULTS Mean relative measurement error from the two phantoms was less than 1% for both observers. A total of 60 emboli were measured from the 30 patients. The intraobserver ICC was 0.990 for observer 1 and 0.999 for observer 2; interobserver ICC was 0.994 for session 1 and 0.989 for session 2. ICC for all four clot measurements was 0.988. Mean volume measurement difference for intraobserver agreement was 0.9% for observer 1 and 0.3% for observer 2, and interobserver agreement was -5.1% for session 1 and -5.8% for session 2. CONCLUSION Blood clot burden can be quantified with a high degree of accuracy and reproducibility from pulmonary CTA images using a semiautomated segmentation method.
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308
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van Langevelde K, Tan M, Srámek A, Huisman MV, de Roos A. Magnetic resonance imaging and computed tomography developments in imaging of venous thromboembolism. J Magn Reson Imaging 2011; 32:1302-12. [PMID: 21105136 DOI: 10.1002/jmri.22379] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Venous thromboembolism (VTE) is a disease that causes high morbidity and mortality in the population. At present the first-line imaging test for a suspected pulmonary embolism (PE) is computed tomography (CT) pulmonary angiography, and ultrasonography is widely used for the diagnosis of deep-vein thrombosis (DVT). Although these modalities are proven to be safe and accurate, unresolved issues remain, such as whether CT scanning in patients with a suspected PE should be extended to the legs. Another issue is the diagnosis of recurrent DVT. Magnetic resonance imaging (MRI) offers a number of advantages in the imaging of VTE. Recent developments of scanning protocols with shorter acquisition times, sometimes complemented by navigator gating or making use of endogenous contrast, offer new perspectives for the use of MRI. This review provides an overview of state of the art MRI techniques for the diagnosis of PE and DVT. Furthermore, the use of new contrast agents such as fibrin labeling to detect thrombi are addressed.
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Affiliation(s)
- Kirsten van Langevelde
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
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309
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Ley S, Grünig E, Kiely DG, van Beek E, Wild J. Computed tomography and magnetic resonance imaging of pulmonary hypertension: Pulmonary vessels and right ventricle. J Magn Reson Imaging 2011; 32:1313-24. [PMID: 21105137 DOI: 10.1002/jmri.22373] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Pulmonary hypertension (PH) is very heterogeneous and the classification identifies five major groups including many associated disease processes. The treatment of PH depends on the underlying cause and accurate classification is paramount. A comprehensive assessment to identify the cause and severity of PH is therefore needed. Furthermore, follow-up assessments are required to monitor changes in disease status and response to therapy. Traditionally, the diagnostic imaging work-up of PH comprised mainly echocardiography, invasive right heart catheterization, and ventilation/perfusion scintigraphy. Due to technical advances, multidetector row computed tomography (CT) and magnetic resonance imaging (MRI) have become important and complementary investigations in the evaluation of patients with suspected PH. Both modalities are reviewed and recommendations for clinical use are given.
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Affiliation(s)
- Sebastian Ley
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany.
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310
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Imagerie hybride dans l’embolie pulmonaire aiguë : apport de la TDM couplée à la tomoscintigraphie de ventilation et de perfusion. MÉDECINE NUCLÉAIRE 2011. [DOI: 10.1016/j.mednuc.2010.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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311
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Aviram G, Steinvil A, Berliner S, Rosen G, Sosna J, Man A, Keren G, Rogowski O. The association between the embolic load and atrial size in acute pulmonary embolism. J Thromb Haemost 2011; 9:293-9. [PMID: 21040447 DOI: 10.1111/j.1538-7836.2010.04130.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Early identification by computed tomography pulmonary angiography (CTPA) of patients with acute pulmonary embolism (PE) who have signs associated with a high embolic burden would be highly desirable. OBJECTIVES To investigate whether an increased obstruction of the pulmonary vasculature is associated with reduced left atrial (LA) and increased right atrial (RA) areas. METHODS We retrospectively analyzed a consecutive series of CTPA studies of 137 patients with acute PE and 38 controls without PE between October 2004 and March 2006. Left and right atrial areas and longitudinal and short axis diameters were measured and correlated with the pulmonary arterial obstruction index (PAOI) divided into tertiles (obstruction of < 12.5%, 12.5%-42.5% and ≥ 42.5%). RESULTS There was a significant negative age- and gender-adjusted correlation between the PAOI and LA measurements, particularly the LA area (r = -0.259) and the LA short axis diameter (r = -0.331). All RA measurements had positive correlations (RA area, r = 0.279; RA short axis diameter, r = 0.313). The LA/RA area ratio correlated negatively with the PAOI (r = -0.447). All above-mentioned correlations had P < 0.002. All the LA measurements were the largest in the controls and gradually decreased with higher PAOIs. A receiver operating characteristic curve analysis demonstrated that the RV/LV diameter, LA/RA area and LA/RA short axis diameter ratios had comparable discriminative ability for higher PAOI tertiles. CONCLUSIONS The higher the clot load in the pulmonary arteries, the smaller the LA area and the larger the RA area. Atrial area measurements by CTPA may serve as a real-time parameter in assessing the severity of PE upon diagnosis.
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Affiliation(s)
- G Aviram
- Department of Radiology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
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312
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Impact of Image Quality on the Performance of Computer-Aided Detection of Pulmonary Embolism. AJR Am J Roentgenol 2011; 196:95-101. [DOI: 10.2214/ajr.09.4165] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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313
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Potentials and limitations of low-concentration contrast medium (150mg iodine/ml) in CT pulmonary angiography. Clin Radiol 2011; 66:43-9. [DOI: 10.1016/j.crad.2010.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 04/25/2010] [Accepted: 05/07/2010] [Indexed: 11/23/2022]
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314
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Henzler T, Barraza JM, Nance JW, Costello P, Krissak R, Fink C, Schoepf UJ. CT imaging of acute pulmonary embolism. J Cardiovasc Comput Tomogr 2011; 5:3-11. [DOI: 10.1016/j.jcct.2010.10.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 10/05/2010] [Indexed: 02/07/2023]
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315
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Jolibert M, Vidal V, Cohen F, Bartoli JM, Moulin G, Jacquier A, Gaubert JY. [Improvement of pulmonary angiography in the framework of a maintenance of certification]. JOURNAL DE RADIOLOGIE 2011; 92:20-24. [PMID: 21352722 DOI: 10.1016/j.jradio.2010.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2010] [Revised: 07/14/2010] [Accepted: 08/09/2010] [Indexed: 05/30/2023]
Abstract
PURPOSE This evaluation of clinical practices (pulmonary embolus) was performed to evaluate the quality of CT pulmonary angiograms for suspected acute pulmonary embolus. MATERIALS AND METHODS Five validated criteria evaluating both the acquisition technique and the quality of image interpretation were selected: slice thickness, pulmonary arterial enhancement over 250 HU, caudocranial acquisition, visualization of fifth order pulmonary arterial branches, and right-left ventricular ratio in the presence of pulmonary embolus. Forty CT pulmonary angiograms were reviewed before and after implementation of a practice quality improvement program: modification of acquisition protocol, training of medical and paramedical staff, and implementation of a standardized radiology report. RESULTS Thin collimation was already implemented. The implementation of two other technical parameters significantly improved the technical quality of the examinations. The detection of findings with adverse clinical outcome was also significantly improved. Only the accuracy of detection of embolus involving fifth order pulmonary arterial branches could not be improved, a criteria allowing formal exclusion of pulmonary embolus. CONCLUSION This study resulted in an improvement in the quality of CT pulmonary angiograms and increased awareness of radiologists for the prognostic value of right ventricular dilatation. It has also underscored the need for quality control of a CT pulmonary angiogram prior to interpretation.
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Affiliation(s)
- M Jolibert
- Service d'imagerie médicale, hôpital de La Timone, CHU de Marseille, 264, rue Saint-Pierre, 13005 Marseille, France. marianne
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316
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Mos IC, Klok FA, Kroft LJ, Huisman MV. Update on techniques for the diagnosis of pulmonary embolism. EXPERT OPINION ON MEDICAL DIAGNOSTICS 2011; 5:49-61. [PMID: 23484476 DOI: 10.1517/17530059.2011.538380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
IMPORTANCE OF THE FIELD The clinical suspicion of acute pulmonary embolism (PE) is frequently raised. However, the diagnosis of PE is confirmed in only 20 - 30% of these patients. The high incidence in addition to the potential harm from false-positive or false-negative diagnostic decisions underline the importance of a standardised diagnostic algorithm with high sensitivity as well as specificity. AREAS COVERED IN THIS REVIEW This article reviews the diagnostic tests for the diagnosis of PE. WHAT THE READER WILL GAIN This review provides an overview of the different clinical decision rules (CDRs), D-dimer tests and imaging techniques in patients suspected of PE. Furthermore, the diagnostic process in patients with clinically suspected recurrent PE, suspicion during pregnancy and new research areas are discussed. TAKE HOME MESSAGE Various diagnostic tests are available to detect or exclude PE with good accuracy. CDRs and D-dimer tests play an important role in the exclusion of PE. Neither is sufficient as a single test, but the combination of an 'unlikely' clinical prediction and a normal D-dimer test result safely excludes PE. In case of a high CDR score and/or an elevated D-dimer concentration, extra imaging is necessary with multi-slice computed tomography pulmonary angiography as first choice modality.
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Affiliation(s)
- Inge Cm Mos
- Leiden University Medical Centre, Section of Vascular Medicine, Department of General Internal Medicine - Endocrinology, Albinusdreef 2, Postbus 9600, 2300 RC Leiden, the Netherlands +003171 5262085 ; +003171 5248140 ;
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317
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Kouskov OS, Nichols DJ, O'Hearn DJ. Paradoxical arterial embolism involving both upper extremities in a patient with pulmonary embolism and a patent foramen ovale. Clin Appl Thromb Hemost 2010; 17:E98-101. [PMID: 21159714 DOI: 10.1177/1076029610387123] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Paradoxical embolization is an uncommon but devastating complication of pulmonary embolism (PE). Awareness of this complication with prompt recognition and treatment could serve to preclude significant disability and death. Described is a case of PE associated with paradoxical embolism to the arteries of both upper extremities. While patent foramen ovale (PFO) is common, paradoxical embolism is infrequent but can involve almost any artery of the body. Discussed are the risk factors, clinical presentations, and diagnostic and treatment options for paradoxical embolism. Awareness of the potential for paradoxical embolization in patients with PE is essential to its prompt recognition and treatment.
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Affiliation(s)
- O S Kouskov
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, OR, USA.
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318
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Cereser L, Bagatto D, Girometti R, Como G, Zuiani C, Bazzocchi M. Chest multidetector computed tomography (MDCT) in patients with suspected acute pulmonary embolism: diagnostic yield and proportion of other clinically relevant findings. LA RADIOLOGIA MEDICA 2010; 116:219-29. [PMID: 21311990 DOI: 10.1007/s11547-010-0612-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 05/11/2010] [Indexed: 11/25/2022]
Abstract
PURPOSE The authors evaluated the diagnostic yield of chest multidetector computed tomography (MDCT) in acute pulmonary embolism (PE) and the proportion of other clinically relevant findings in a large cohort of consecutive inpatients and patients referred from the emergency department (outpatients). MATERIALS AND METHODS A total of 327 radiological reports of chest MDCT scans performed for suspected acute PE in 327 patients (158 men, 169 women; mean age 69 years, standard deviation 17.33 years; 233 inpatients, 94 outpatients) were retrospectively evaluated and classified into four categories: 1, positive for PE; 2, negative for PE but positive for other findings requiring specific and immediate intervention; 3, completely negative or positive for findings with a potential for significant morbidity requiring specific action on follow-up; 4, indeterminate. The distribution of findings by categories among the entire population and inpatients and outpatients separately was calculated (chi-square test, α=0.05). RESULTS In the entire population, the diagnostic yield (i.e. proportion of cases classified as category 1) was 20.2% (66/327). Proportions of cases classified as categories 2, 3 and 4 were 27.5% (90/327), 44.3% (145/327) and 7.9% (26/327), respectively. No statistically significant difference was found between inpatients and outpatients (p=0.193). CONCLUSIONS In patients with suspected acute PE, chest MDCT provides evidence of conditions requiring immediate and specific intervention (i.e. categories 1 and 2) in nearly 50% of cases, without differences between inpatients and outpatients.
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Affiliation(s)
- L Cereser
- Institute of Diagnostic Radiology, University of Udine, Via Colugna 50, 33100, Udine, Italy.
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Detection of pulmonary embolism comparison between dual energy CT and MR angiography in a rabbit model. Acad Radiol 2010; 17:1550-9. [PMID: 21056850 DOI: 10.1016/j.acra.2010.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/15/2010] [Accepted: 09/22/2010] [Indexed: 11/21/2022]
Abstract
RATIONALE AND OBJECTIVES The purpose of this study was to compare the efficacy of dual-energy computed tomography (DECT), time-resolved magnetic resonance (MR) imaging (MRI) perfusion measurements, and high-resolution MR angiography (MRA) for the detection of pulmonary embolism (PE) in a rabbit model. MATERIALS AND METHODS Two hours after Gelfoam (n = 16) or saline (n = 2) injection into the femoral vein, 18 rabbits were first imaged using dual-energy computed tomographic pulmonary angiography (CTPA), from which blood flow imaging (BFI) were produced. Next, the rabbits underwent time-resolved MR perfusion measurements and MRA using a 3.0-T scanner. Two radiologists who were blinded to histopathologic findings independently evaluated the results of CTPA, BFI, time-resolved MR perfusion, and MRA for each rabbit and recorded the locations and number of pulmonary clots on a per lobe basis. Immediately after MRI examination, pathologic determination of the locations and numbers of lung lobes with PE was recorded. Histopathologic results served as the reference standard to determine the sensitivity and specificity of DECT (BFI and CTPA) and MRI (time-resolved MR perfusion and high-resolution MRA) for the detection of PE. RESULTS The induction of PE was successful in all animals, but three rabbits were excluded because of death prior to MRI procedures (caused by complications during the embolization procedure); only data from the remaining 15 rabbits were included in the final analysis. Histopathology demonstrated 24 lobes with clots and 51 lobes without clots. CTPA, BFI, and MRI correctly identified PE in 23, 23, and 20 lobes, respectively, and the absence of emboli in 48, 46, and 46 lobes, respectively; these results corresponded to sensitivities of 95.8%, 95.8%, and 83.3% and specificities of 94.1%, 90.2%, and 90.2% for reader 1 and sensitivities of 91.7%, 91.7%, and 87.5% and specificities of 90.2%, 88.2%, and 88.2% for reader 2 for CTPA, BFI, and MRI, respectively. Good or excellent intermodality and interreader agreement among CTPA, BFI, and MRI were found. CONCLUSIONS DECT can simultaneously provide high-resolution pulmonary artery and lung iodine mapping with slightly high diagnostic accuracy for the detection of PE compared to MRI in an experimental rabbit model of PE. This improvement was not statistically significant given the study sample size.
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321
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Feasibility of gadolinium-enhanced dual energy CT pulmonary angiography: a pilot study in rabbits. Int J Cardiovasc Imaging 2010; 27:1069-80. [DOI: 10.1007/s10554-010-9755-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 11/12/2010] [Indexed: 10/18/2022]
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322
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Pontana F, Pagniez J, Flohr T, Faivre JB, Duhamel A, Remy J, Remy-Jardin M. Chest computed tomography using iterative reconstruction vs filtered back projection (Part 1): evaluation of image noise reduction in 32 patients. Eur Radiol 2010; 21:627-35. [PMID: 21053003 DOI: 10.1007/s00330-010-1990-5] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 09/13/2010] [Accepted: 10/08/2010] [Indexed: 01/12/2023]
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323
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Durán-Mendicuti A, Sodickson A. Imaging evaluation of the pregnant patient with suspected pulmonary embolism. Int J Obstet Anesth 2010; 20:51-9. [PMID: 21036031 DOI: 10.1016/j.ijoa.2010.07.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 02/17/2010] [Accepted: 07/23/2010] [Indexed: 11/24/2022]
Abstract
Pulmonary embolism is the leading cause of maternal death in the developed world. The clinical diagnosis of pulmonary embolism is particularly challenging in pregnant patients as physiologic changes of pregnancy can mimic symptoms of pulmonary embolism or deep venous thrombosis. Clinical decision and imaging algorithms for venous thromboembolic disease have been proposed in the literature for the general population, but have not undergone wide-scale validation in pregnant patients. Laboratory evaluation of D-dimer levels has likewise been established as a viable screening method in the general population but remains controversial in pregnant patients. Regardless of whether D-dimer levels are used in this population, the clinician must often rely on imaging tests to confirm or exclude a clinical suspicion of pulmonary embolism. Additional factors beyond test performance must be weighed during pregnancy: radiation exposure to the fetus and maternal breast tissue, the safety of intravenous contrast administration and the diagnostic accuracy of the various testing options so that diagnosis and proper management are not delayed. The epidemiology of pregnancy-related venous thromboembolic disease and the different diagnostic methods are reviewed, with emphasis on the pregnant patient. Finally, a diagnostic imaging algorithm is proposed for the evaluation of the pregnant patient when a clinical suspicion of pulmonary embolism exists.
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Affiliation(s)
- A Durán-Mendicuti
- Emergency Radiology Division, Radiology Department, Brigham and Women's Hospital, Boston, MA, USA
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324
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Niemann T, Nicolas G, Roser HW, Müller-Brand J, Bongartz G. Imaging for suspected pulmonary embolism in pregnancy-what about the fetal dose? A comprehensive review of the literature. Insights Imaging 2010; 1:361-372. [PMID: 22347929 PMCID: PMC3259315 DOI: 10.1007/s13244-010-0043-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 08/13/2010] [Accepted: 09/15/2010] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVE: To give a comprehensive overview of fetal doses reported in the literature when imaging the pregnant woman with suspected pulmonary embolism (PE). METHODS: A comprehensive literature search in the PubMed, MEDLINE and EMBASE databases yielded a total of 1,687 papers that were included in the analysis and have been analysed with regard to fetal dose in suspected PE radiological imaging strategies. RESULTS: Fetal dose in chest computed tomography (CT) ranges between 0.013 and 0.026 mGy in early and 0.06-0.1 mGy in late pregnancy compared with 99mTc-MAA perfusion scintigraphy with a fetal dose of 0.1-0.6 mGy in early and 0.6-0.8 mGy in late pregnancy. (99m)Tc-aerosol ventilation scintigraphy results in 0.1-0.3 mGy. However, there is concern about female breast irradiation in CT, which is higher than in scintigraphy. CT radiation risks for breast tissue remain unclear. CONCLUSION: Knowledge of dosimetry and radiation risks is crucial in the radiological work-up of suspected PE in pregnancy. It is reasonable to reserve scintigraphy for pregnant patients with normal chest radiography findings and no history of asthma or chronic lung disease. Performing CT applying dose reduction instead of scintigraphy will minimise fetal radiation dose and maximise the diagnostic value.
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325
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Pistolesi M. Pulmonary CT angiography in patients suspected of having pulmonary embolism: case finding or screening procedure? Radiology 2010; 256:334-7. [PMID: 20656827 DOI: 10.1148/radiol.10100662] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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326
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Atalay MK, Haji-Momenian S, Grand DJ. Three Contrast Injection Protocols for Electrocardiogram-Gated 64-Slice Computed Tomographic Angiography. J Comput Assist Tomogr 2010; 34:660-5. [DOI: 10.1097/rct.0b013e3181e40793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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327
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Initial experience of dual-energy lung perfusion CT using a dual-source CT system in children. Pediatr Radiol 2010; 40:1536-44. [PMID: 20596701 DOI: 10.1007/s00247-010-1759-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 05/10/2010] [Accepted: 05/14/2010] [Indexed: 12/13/2022]
Abstract
Initial experience of dual-source dual-energy (DE) lung perfusion CT in children is described. In addition to traditional identification of pulmonary emboli, the assessment of lung perfusion is technically feasible with dual-source DE CT in children with acceptable radiation dose. This article describes how to perform dual-source DE lung perfusion CT in children, including the optimization of intravenous injection method and CT dose parameters. How to produce weighted-average CT images for the assessment of pulmonary emboli and colour-coded perfusion maps for the assessment of regional lung perfusion is also detailed. Lung perfusion status can then be evaluated on perfusion maps by means of either qualitative or quantitative analysis. Potential advantages and disadvantages of this emerging CT technique compared to lung perfusion scintigraphy and cardiac MRI are discussed.
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328
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Hoffmann B, Gullett JP. Bedside transthoracic sonography in suspected pulmonary embolism: a new tool for emergency physicians. Acad Emerg Med 2010; 17:e88-93. [PMID: 20836767 DOI: 10.1111/j.1553-2712.2010.00831.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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329
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Computed tomography for the detection of free-floating thrombi in the right heart in acute pulmonary embolism. Eur Radiol 2010; 21:240-5. [DOI: 10.1007/s00330-010-1942-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Revised: 06/27/2010] [Accepted: 07/14/2010] [Indexed: 10/19/2022]
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330
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Hunsaker AR, Lu MT, Goldhaber SZ, Rybicki FJ. Imaging in acute pulmonary embolism with special clinical scenarios. Circ Cardiovasc Imaging 2010; 3:491-500. [PMID: 20647583 DOI: 10.1161/circimaging.109.855981] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Andetta R Hunsaker
- Applied Imaging Science Laboratory, the Thoracic Imaging Section, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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331
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Nyman U. Routine Use of a V/Q SPECT/Low-Dose CT Hybrid System to Diagnose Pulmonary Embolism Seems Premature. J Nucl Med 2010; 51:1329-30; author reply 1330. [DOI: 10.2967/jnumed.110.077313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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332
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Mamlouk MD, vanSonnenberg E, Gosalia R, Drachman D, Gridley D, Zamora JG, Casola G, Ornstein S. Pulmonary Embolism at CT Angiography: Implications for Appropriateness, Cost, and Radiation Exposure in 2003 Patients. Radiology 2010; 256:625-32. [DOI: 10.1148/radiol.10091624] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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333
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Contrast Opacification Using a Reduced Volume of Iodinated Contrast Material and Low Peak Kilovoltage in Pulmonary CT Angiography: Objective and Subjective Evaluation. AJR Am J Roentgenol 2010; 195:W118-24. [PMID: 20651170 DOI: 10.2214/ajr.09.3342] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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334
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Abstract
Pulmonary embolism (PE) is a frequently occurring, acute, and potentially fatal condition. Numerous risk factors for PE, both inherited and acquired, have been identified. Adequate diagnosis is mandatory to prevent PE-related morbidity and mortality on the one hand, and unnecessary treatment on the other. Only around 1 in 5 individuals with suspected PE will have the diagnosis confirmed, therefore, the diagnostic work-up for PE should comprise safe, efficient, and noninvasive methods. The first step in the approach to diagnosis of patients with suspected PE is to determine the clinical probability and to perform a D-dimer test. PE can be excluded in patients with a 'low', 'intermediate' or 'unlikely' clinical probability and a normal D-dimer test. Additional imaging is required for those with a 'high' or 'likely' clinical probability or a positive D-dimer test. CT pulmonary angiography or ventilation-perfusion scintigraphy, followed by additional testing is the next step when test results are nondiagnostic. Although various diagnostic strategies have been introduced and validated, selected patients may require a tailored approach.
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Affiliation(s)
- Renée A Douma
- Department of Vascular Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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335
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Affiliation(s)
- Giancarlo Agnelli
- Internal and Cardiovascular Medicine and Stroke Unit, University of Perugia, Perugia, Italy.
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336
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Lu GM, Wu SY, Yeh BM, Zhang LJ. Dual-energy computed tomography in pulmonary embolism. Br J Radiol 2010; 83:707-18. [PMID: 20551257 DOI: 10.1259/bjr/16337436] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The introduction of modern dual-energy CT (DECT) scanners has enabled contrast material to be distinguished at imaging without the need for a separate unenhanced scan. Images of pulmonary parenchymal contrast enhancement obtained using DECT improve the detection of defects, augmenting our ability to detect pulmonary emboli; however, with these advances new pitfalls are also introduced. In this pictorial review, we present the technique, clinical applications and causes and remedies of false results of dual-energy pulmonary parenchymal enhancement defects in pulmonary embolism.
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Affiliation(s)
- G-M Lu
- Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu 210002, China.
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337
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Enhanced Visualization of Lung Vessels for Diagnosis of Pulmonary Embolism Using Dual Energy CT Angiography. Invest Radiol 2010; 45:341-6. [DOI: 10.1097/rli.0b013e3181dfda37] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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338
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Lee EY, Kritsaneepaiboon S, Arellano CMR, Grace RF, Zurakowski D, Boiselle PM. Unsuspected Pulmonary Emboli in Pediatric Oncology Patients: Detection With MDCT. AJR Am J Roentgenol 2010; 194:1216-1222. [DOI: 10.2214/ajr.09.3463] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- Edward Y. Lee
- Department of Radiology, Children's Hospital Boston and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115
| | - Supika Kritsaneepaiboon
- Department of Radiology, Children's Hospital Boston and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115
- Department of Radiology, Prince of Songkla University, Hat Yai, Thailand
| | | | - Rachael F. Grace
- Department of Pediatric Oncology, Division of Hematology/Oncology, Dana–Farber Cancer Institute and Harvard Medical School, Boston, MA
| | - David Zurakowski
- Departments of Anesthesia and Surgery, Children's Hospital Boston and Harvard Medical School, Boston, MA
| | - Phillip M. Boiselle
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
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339
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Stein EG, Haramati LB, Bellin E, Ashton L, Mitsopoulos G, Schoenfeld A, Amis ES. Radiation Exposure From Medical Imaging in Patients With Chronic and Recurrent Conditions. J Am Coll Radiol 2010; 7:351-9. [DOI: 10.1016/j.jacr.2009.12.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Accepted: 12/28/2009] [Indexed: 10/19/2022]
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340
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Suh JM, Cronan JJ, Healey TT. Dots are not clots: the over-diagnosis and over-treatment of PE. Emerg Radiol 2010; 17:347-52. [PMID: 20217446 DOI: 10.1007/s10140-010-0863-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Accepted: 02/12/2010] [Indexed: 10/19/2022]
Abstract
The purpose of this work is to question the conventional theory that all pulmonary emboli (PE) are abnormal, and to test the hypothesis that small peripheral PE are a function of life. Most radiologists report any filling defect, independent of size, as clinically significant PE when detected in the pulmonary arteries. We sought to reinforce the theory that small dots in the pulmonary arteries are not clinically significant clots in the conventional setting. The necessity for anticoagulation should be balanced against the risk of bleeding. This retrospective HIPAA-compliant study was approved by the institutional review board; informed consent was not required. All patients diagnosed with PE by 16-slice or 64-slice multidetector computed tomography (CT) over a 6-month period who also had a lower extremity venous ultrasound (US) performed within 7 days of CT were identified. The study group included 26 women and 24 men (mean, 56 years; range, 21-90 years). The locations of the PE were plotted on a pulmonary arterial diagram, and width of the most proximal clot for each patient was measured. Of 1,273 consecutive CT studies, 101 were positive (7.9%) and 50 patients underwent lower extremity US. Thirty-three (66%) patients had PE in the central pulmonary arteries, of which 19 (58%) had deep vein thrombosis (DVT). Seventeen (34%) patients had peripheral PE; DVT was detected in 0 (0%) patients. The peripheral clots measured 1.0-3.8 mm (mean, 2.5 mm). These clots appeared focal and rounded with a "dot-like" appearance. Peripheral, focal filling defects in the pulmonary arteries, which we termed "dots," are not traditional embolic clots, are not associated with detectable lower-extremity clot load, and may represent "normal" embolic activity originating from the lower extremity venous valves. We suggest that more in-depth understanding about small peripheral PE is needed. The necessity of conventional anticoagulation should be critically reviewed in patients with subsegmental PE and minimal clot burden.
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Affiliation(s)
- Jane M Suh
- Department of Diagnostic Imaging, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI 02903, USA
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341
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Huppmann MV, Johnson WB, Javitt MC. Radiation Risks from Exposure to Chest Computed Tomography. Semin Ultrasound CT MR 2010; 31:14-28. [DOI: 10.1053/j.sult.2009.09.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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342
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Success of a Safe and Simple Algorithm to Reduce Use of CT Pulmonary Angiography in the Emergency Department. AJR Am J Roentgenol 2010; 194:392-7. [DOI: 10.2214/ajr.09.2499] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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343
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344
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345
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A United Kingdom based survey of clinical practice in the diagnosis of suspected pulmonary embolism. Nucl Med Commun 2010; 31:112-20. [PMID: 19898262 DOI: 10.1097/mnm.0b013e3283304a29] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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346
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Lessler AL, Isserman JA, Agarwal R, Palevsky HI, Pines JM. Testing low-risk patients for suspected pulmonary embolism: a decision analysis. Ann Emerg Med 2010; 55:316-326.e1. [PMID: 20061065 DOI: 10.1016/j.annemergmed.2009.12.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2009] [Revised: 11/22/2009] [Accepted: 12/02/2009] [Indexed: 12/31/2022]
Abstract
STUDY OBJECTIVE The Pulmonary Embolism Rule-out Criteria (PERC) identifies low-risk patients who are treated in the emergency department for suspected pulmonary embolism and for whom testing may be deferred. The purpose of this study is to develop a decision model to determine whether certain elements not included in the PERC methodology could better estimate the testing threshold for pulmonary embolism (ie, the pretest probability below which a patient should not be tested for pulmonary embolism). In addition, we determine which risks and benefits of pulmonary embolism evaluation and treatment have the greatest effect on the testing threshold. METHODS We built decision models of low-risk patients with suspected pulmonary embolism, as determined by the PERC. We obtained model inputs from the literature or by using clinical judgment when data were unavailable. One-way sensitivity analysis derived the testing threshold, and 2-way sensitivity analysis was used to determine the main drivers of the testing threshold. RESULTS We found an average testing threshold of 1.4% across all age and sex cohorts. Two-way sensitivity analysis demonstrated that risk of major bleeding from anticoagulation, mortality from contrast-induced renal failure, risk of cancer from computed tomography scan, and mortality from both treated and untreated pulmonary embolism had the greatest effects on the testing threshold. CONCLUSION We found a testing threshold for the PERC similar to that calculated by the Pauker and Kassirer method, using somewhat different assumptions. The 5 major drivers for the testing threshold are variables for which there is a paucity of literature to assess accurately for low-risk patients.
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Affiliation(s)
- Adam L Lessler
- Department of Emergency Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
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347
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Dose reduction in computed tomographic angiography of pregnant patients with suspected acute pulmonary embolism. J Comput Assist Tomogr 2010; 33:961-6. [PMID: 19940668 DOI: 10.1097/rct.0b013e318198cd18] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to quantify the effect of a reduced-dose pulmonary computed tomographic (CT) angiography protocol on radiation dose and image quality in pregnant patients as compared with a standard protocol. MATERIALS AND METHODS Twenty-six pregnant women with suspected pulmonary embolism underwent reduced-dose CT angiography (200 mA and 100 kV, from the aortic arch to the diaphragm). The matched control group standard protocol was 400 mA, 120 kilovolt (peak), and the entire thorax. The CT dose index, dose-length product, effective dose, image quality, and signal-to-noise ratio were assessed and compared with the Wilcoxon rank sum test result. RESULTS The CT dose index, mean dose-length product, and calculated effective dose were lower in the pregnancy group than in the controls: mean (SD), 5.21 (1.54) mGy versus 20.86 (5.59) mGy; 105.65 (39.77) mGy cm versus 575.71 (154.86) mGy cm, and 1.79 (0.676) msv versus 9.787 (2.63) msv, respectively (P < 0.0001). Quality scores of segmental (P = 0.266) and subsegmental (P = 0.207) arteries and arterial attenuation (P = 0.443) were similar. CONCLUSIONS In pregnant patients with suspected pulmonary embolism, combined reduction of kilovoltage and milliampere-second settings and z-axis coverage results in a substantial reduction of radiation dose while maintaining diagnostic imaging quality.
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348
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349
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Computer-Aided Detection of Acute Pulmonary Embolism With 64-Slice Multi-Detector Row Computed Tomography. J Comput Assist Tomogr 2010; 34:23-30. [DOI: 10.1097/rct.0b013e3181b2e383] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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