scholarly journals Canadian Society of Thoracic Radiology/Canadian Association of Radiologists Best Practice Guidance for Investigation of Acute Pulmonary Embolism, Part 2: Technical Issues and Interpretation Pitfalls

2021 ◽  
pp. 084653712110007
Author(s):  
Elsie T. Nguyen ◽  
Cameron Hague ◽  
Daria Manos ◽  
Brett Memauri ◽  
Carolina Souza ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Image Quality ◽  
Best Practice ◽  
Acute Pulmonary Embolism ◽  
Reporting Quality ◽  
Diagnostic Quality ◽  
Pulmonary Angiogram ◽  
Canadian Association ◽  
Clinical Scenarios

The investigation of acute pulmonary embolism is a common task for radiologists in Canada. Technical image quality and reporting quality must be excellent; pulmonary embolism is a life-threatening disease that should not be missed but overdiagnosis and unnecessary treatment should be avoided. The most frequently performed imaging investigation, computed tomography pulmonary angiogram (CTPA), can be limited by poor pulmonary arterial opacification, technical artifacts and interpretative errors. Image quality can be affected by patient factors (such as body habitus, motion artifact and cardiac output), intravenous (IV) contrast protocols (including the timing, rate and volume of IV contrast administration) and common physics artifacts (including beam hardening). Mimics of acute pulmonary embolism can be seen in normal anatomic structures, disease in non-vascular structures and pulmonary artery filling defects not related to acute pulmonary emboli. Understanding these pitfalls can help mitigate error, improve diagnostic quality and optimize patient outcomes. Dual energy computed tomography holds promise to improve imaging diagnosis, particularly in clinical scenarios where routine CTPA may be problematic, including patients with impaired renal function and patients with altered cardiac anatomy.

Using 100- instead of 120-kVp computed tomography to diagnose pulmonary embolism almost halves the radiation dose with preserved diagnostic quality

2010 ◽  
Vol 51 (3) ◽  
pp. 260-270 ◽  
Author(s):  
Peter Björkdahl ◽  
Ulf Nyman
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Image Quality ◽  
Radiation Dose ◽  
Effective Dose ◽  
Ct Number ◽  
Subjective Image Quality ◽  
Diagnostic Quality ◽  
X Ray ◽  
Tube Potential

Background: Concern has been raised regarding the mounting collective radiation doses from computed tomography (CT), increasing the risk of radiation-induced cancers in exposed populations. Purpose: To compare radiation dose and image quality in a chest phantom and in patients for the diagnosis of pulmonary embolism (PE) at 100 and 120 peak kilovoltage (kVp) using 16-multichannel detector computed tomography (MDCT). Material and Methods: A 20-ml syringe containing 12 mg I/ml was scanned in a chest phantom at 100/120 kVp and 25 milliampere seconds (mAs). Consecutive patients underwent 100 kVp ( n = 50) and 120 kVp ( n = 50) 16-MDCT using a “quality reference” effective mAs of 100, 300 mg I/kg, and a 12-s injection duration. Attenuation (CT number), image noise (1 standard deviation), and contrast-to-noise ratio (CNR; fresh clot = 70 HU) of the contrast medium syringe and pulmonary arteries were evaluated on 3-mm-thick slices. Subjective image quality was assessed. Computed tomography dose index (CTDIvol) and dose–length product (DLP) were presented by the CT software, and effective dose was estimated. Results: Mean values in the chest phantom and patients changed as follows when X-ray tube potential decreased from 120 to 100 kVp: attenuation +23% and +40%, noise +38% and +48%, CNR −6% and 0%, and CTDIvol −38% and −40%, respectively. Mean DLP and effective dose in the patients decreased by 42% and 45%, respectively. Subjective image quality was excellent or adequate in 49/48 patients at 100/120 kVp. No patient with a negative CT had any thromboembolism diagnosed during 3-month follow-up. Conclusion: By reducing X-ray tube potential from 120 to 100 kVp, while keeping all other scanning parameters unchanged, the radiation dose to the patient may be almost halved without deterioration of diagnostic quality, which may be of particular benefit in young individuals.

Is a normal computed tomography pulmonary angiography safe to rule out acute pulmonary embolism in patients with a likely clinical probability?

2017 ◽  
Vol 117 (08) ◽  
pp. 1622-1629 ◽  
Author(s):  
Tom van der Hulle ◽  
Nick van Es ◽  
Paul den Exter ◽  
Josien van Es ◽  
Inge Mos ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Acute Pulmonary Embolism ◽  
Meta Analysis ◽  
Pulmonary Angiography ◽  
Computed Tomography Pulmonary Angiography ◽  
Clinical Probability ◽  
Pulmonary Angiogram ◽  
Wells Rule ◽  
Rule Out

SummaryA normal computed tomography pulmonary angiography (CTPA) remains a controversial criterion for ruling out acute pulmonary embolism (PE) in patients with a likely clinical probability. We set out to determine the risk of VTE and fatal PE after a normal CTPA in this patient category and compare these risk to those after a normal pulmonary angiogram of 1.7% (95%CI 1.0–2.7%) and 0.3% (95%CI 0.02–0.7%). A patient-level meta-analysis from 4 prospective diagnostic management studies that sequentially applied the Wells rule, D-dimer tests and CTPA to consecutive patients with clinically suspected acute PE. The primary outcome was the 3-month VTE incidence after a normal CTPA. A total of 6,148 patients were included with an overall PE prevalence of 24%. The 3-month VTE incidence in all 4,421 patients in whom PE was excluded at baseline was 1.2% (95%CI 0.48–2.6) and the risk of fatal PE was 0.11% (95%CI 0.02–0.70). In patients with a likely clinical probability the 3-month incidences of VTE and fatal PE were 2.0% (95%CI 1.0–4.1%) and 0.48% (95%CI 0.20–1.1%) after a normal CTPA. The 3-month incidence of VTE was 6.3% (95%CI 3.0–12) in patients with a Wells rule >6 points. In conclusion, this study suggests that a normal CTPA may be considered as a valid diagnostic criterion to rule out PE in the majority of patients with a likely clinical probability, although the risk of VTE is higher in subgroups such as patients with a Wells rule >6 points for which a closer follow-up should be considered.Supplementary Material to this article is available online at www.thrombosis-online.com.

scholarly journals Canadian Society of Thoracic Radiology/Canadian Association of Radiologists Best Practice Guidance for Investigation of Acute Pulmonary Embolism, Part 1: Acquisition and Safety Considerations

2021 ◽  
pp. 084653712110007
Author(s):  
Elsie T. Nguyen ◽  
Cameron Hague ◽  
Daria Manos ◽  
Brett Memauri ◽  
Carolina Souza ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Best Practice ◽  
Acute Pulmonary Embolism ◽  
Post Partum ◽  
Circulatory System ◽  
Diagnostic Techniques ◽  
Guidance Document ◽  
Diagnostic Challenge ◽  
Intravenous Contrast ◽  
Canadian Association

Acute pulmonary embolism (APE) is a well-recognized cause of circulatory system compromise and even demise which can frequently present a diagnostic challenge for the physician. The diagnostic challenge is primarily due to the frequency of indeterminate presentations as well as several other conditions which can have a similar clinical presentation. This often obliges the physician to establish a firm diagnosis due to the potentially serious outcomes related to this disease. Computed tomography pulmonary angiography (CTPA) has increasingly cemented its role as the primary investigation tool in this clinical context and is widely accepted as the standard of care due to several desired attributes which include great accuracy, accessibility, rapid turn-around time and the ability to suggest an alternate diagnosis when APE is not the culprit. In Part 1 of this guidance document, a series of up-to-date recommendations are provided to the reader pertaining to CTPA protocol optimization (including scan range, radiation and intravenous contrast dose), safety measures including the departure from breast and gonadal shielding, population-specific scenarios (pregnancy and early post-partum) and consideration of alternate diagnostic techniques when clinically deemed appropriate.

scholarly journals Computed Tomography Pulmonary Perfusion for Prediction of Short-Term Clinical Outcome in Acute Pulmonary Embolism

TH Open ◽  
2021 ◽  
Vol 05 (01) ◽  
pp. e66-e72
Author(s):  
Lisette F. van Dam ◽  
Lucia J. M. Kroft ◽  
Menno V. Huisman ◽  
Maarten K. Ninaber ◽  
Frederikus A. Klok
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Predictive Value ◽  
Acute Pulmonary Embolism ◽  
Clinical Presentation ◽  
Reperfusion Therapy ◽  
Pulmonary Perfusion ◽  
Short Term ◽  
Acute Pe ◽  
Related Mortality

Abstract Background Computed tomography pulmonary angiography (CTPA) is the imaging modality of choice for the diagnosis of acute pulmonary embolism (PE). With computed tomography pulmonary perfusion (CTPP) additional information on lung perfusion can be assessed, but its value in PE risk stratification is unknown. We aimed to evaluate the correlation between CTPP-assessed perfusion defect score (PDS) and clinical presentation and its predictive value for adverse short-term outcome of acute PE. Patients and Methods This was an exploratory, observational study in 100 hemodynamically stable patients with CTPA-confirmed acute PE in whom CTPP was performed as part of routine clinical practice. We calculated the difference between the mean PDS in patients with versus without chest pain, dyspnea, and hemoptysis and 7-day adverse outcome. Multivariable logistic regression analysis and likelihood-ratio test were used to assess the added predictive value of PDS to CTPA parameters of right ventricle dysfunction and total thrombus load, for intensive care unit admission, reperfusion therapy and PE-related death. Results We found no correlation between PDS and clinical symptoms. PDS was correlated to reperfusion therapy (n = 4 with 16% higher PDS, 95% confidence interval [CI]: 3.5–28%) and PE-related mortality (n = 2 with 22% higher PDS, 95% CI: 4.9–38). Moreover, PDS had an added predictive value to CTPA assessment for PE-related mortality (from Chi-square 14 to 19, p = 0.02). Conclusion CTPP-assessed PDS was not correlated to clinical presentation of acute PE. However, PDS was correlated to reperfusion therapy and PE-related mortality and had an added predictive value to CTPA-reading for PE-related mortality; this added value needs to be demonstrated in larger studies.

Clinical Usefulness of Computed Tomography Study Without Contrast Injection in the Evaluation of Acute Pulmonary Embolism

2005 ◽  
Vol 29 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Rocco Cobelli ◽  
Maurizio Zompatori ◽  
Giovanni De Luca ◽  
Gianfranco Chiari ◽  
Paolo Bresciani ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Acute Pulmonary Embolism ◽  
Clinical Usefulness ◽  
Contrast Injection

McConnell’s Sign As An indicator of Right Ventricular Infarction: A Case Report

2021 ◽  
Author(s):  
Judah Nijas Arul ◽  
Preetam Krishnamurthy ◽  
Balakrishnan Vinod Kumar ◽  
Thoddi Ramamurthy Muralidharan ◽  
Senguttuvan Nagendra Boopathy ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Right Ventricular ◽  
Medical Management ◽  
Acute Pulmonary Embolism ◽  
Ventricular Dysfunction ◽  
Right Ventricular Dysfunction ◽  
Right Ventricular Infarction ◽  
Coronary Syndrome ◽  
Pulmonary Angiogram ◽  
Ventricular Infarction

Abstract BackgroundMcConnell’s sign is a specific echocardiographic finding that was first described in patient with acute pulmonary embolism signifying right ventricular dysfunction. It remains an under-recognized sign in patients with right ventricular infarction.Case PresentationAn 80-year-old woman presented with sudden onset chest pain and breathlessness. The electrocardiogram showed features suggestive of inferior, posterior, and right ventricular infarction with complete heart block and McConnell’s sign was seen on the echocardiography. CT pulmonary angiogram ruled out the present of pulmonary thromboembolism. Coronary angiogram revealed an occluded right coronary artery with collateral supply from the left circulation. Medical management was planned after patient-physician discussion. Patient symptomatically improved with medical management.ConclusionAlthough McConnell’s sign is suggestive of acute pulmonary embolism, it may also be present in patients with right ventricular dysfunction due to infarction. The presence of McConnell’s sign in a patient presenting with acute coronary syndrome should prompt evaluation for right ventricular infarction in the absence of acute pulmonary embolism.

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