Multidetector Computed Tomography Pulmonary Angiography Research Articles

Modern imaging of acute pulmonary embolism

The first-choice imaging test for visualization of thromboemboli in the pulmonary vasculature in patients with suspected acute pulmonary embolism (PE) is multidetector computed tomography pulmonary angiography (CTPA) – a readily available and widely used imaging technique. Through technological advancements over the past years, alternative imaging techniques for the diagnosis of PE have become available, whilst others are still under investigation. In particular, the evolution of artificial intelligence (AI) is expected to enable further innovation in diagnostic management of PE. In this narrative review, current CTPA techniques and the emerging technology photon-counting CT (PCCT), as well as other modern imaging techniques of acute PE are discussed, including CTPA with iodine maps based on subtraction or dual-energy acquisition, single-photon emission CT (SPECT), magnetic resonance angiography (MRA), and magnetic resonance direct thrombus imaging (MRDTI). Furthermore, potential applications of AI are discussed.

Predictive accuracy of years score in diagnosis of pulmonary embolism

BackgroundPulmonary embolism (PE) is a sudden obstruction of pulmonary arteries usually associated with a high rate of mortality due to acute right ventricular failure. Early diagnosis is of much importance because most patients die within the first hours of presentation. Emergency management is usually highly valuable and right heart failure is potentially reversible. Multidetector computed tomography pulmonary angiography (CTPA) is the best diagnostic imaging modality to document acute pulmonary embolism. Overuse of CTPA increases the unrequired risk of radiation exposure, increasing the risk of malignancy, contrast-related anaphylaxis, and acute kidney injury. To abolish these issues, the simplified score for suspected acute pulmonary embolism using variable D dimer cut-off value in combination with clinical signs can exclude pulmonary embolism safely.Aim of the studyTo evaluate the predictive accuracy of YEARS score in the diagnosis of pulmonary embolism compared to CTPA that might lead to a decrease in the overuse of CTPA.MethodsThe study was held at the chest unit in Kasr ElAini hospitals. It included 50 patients, for which full history, examination, calculation of wells score, D-dimer, YEARS score, and CTPA were done.ResultsThe results showed that the YEARS score succeeded in predicting the presence or the absence of PE in 80% of the 50 enrolled patients in our study. YEARS score has a sensitivity of 90% and specificity of 65%.ConclusionPatients with zero YEARS score and D-dimer ≥ 1000 ng/ml as well as those with ≥ 1 YEARS score and D-dimer ≥ 500 ng/ml are rendered PE likely by the YEARS algorithm with a sensitivity of 90%. Using years score, we can exclude pulmonary embolism in patients with zero YEARS score and a D-dimer ˂ 1000 ng/ml as well as in patients with ≥ 1 YEARS score and D-dimer ˂ 500 ng/ml with 65% specificity, thus decreasing overuse of CTPA in the diagnosis of PE.

Sex differences in the prognostic value of computed tomography pulmonary angiography parameters for intrahospital acute pulmonary embolism-related death

Background/Aim. Multidetector computed tomography pulmonary angiography (MCTPA) has emerged as the most suitable method for diagnosing acute pulmonary embolism (APE) in hemodynamically stable patients. In addition to its diagnostic role, MCTPA facil itates the measurement and calculation of certain parameters that can be used as prognostic markers for outcomes in APE. Since the introduction of the method, there have been a lot of studies that pointed out there may be a significant difference in the prognostic value of MCTPA for APE concerning sex. Methods. The study population consisted of consecutive patients with a diagnosis of APE confirmed by MCTPA. Positive MCTPA findings and a diagnosis of APE were established if the patient had at least one segmental artery thrombus. APE severity was estimated using the simplified Pulmonary Embolism Severity Index (sPESI). Allcause and APE-related intrahospital (Ih) deaths were the coprimary outcomes of this study. Results. In total, 1,612 patients were enrolled in the study (750 men and 862 women). Women with a centrally positioned pulmonary thrombus detected on MCTPA were more likely to die from PE-related death than those without one (10.4% vs. 4.2%, respectively; p = 0.016). Women with a right ventricle (RV) and left ventricle (LV) diameter ratio (RV/LV) > 1 died almost twice as often as those with a ratio ? 1 (15.5% vs. 8.6%, respectively; p = 0.017). Women with an RV/LV > 1 detected with MCTPA were significantly more likely to die from PE than those with a ratio ? 1 (11% vs. 5.2%, respectively; p = 0.017). Women who died from PE-related causes had a significantly higher value of the embolic burden score system (EBSS) than did the surviving women (18.00 vs. 11.00, respectively; p = 0.025). Independently of age, sPESI, and renal function, the presence of a central thrombus [odds ratio (OR) 2.278, 95% confidence interval (CI): 1.050-4.944, p = 0.037] and the RV/LV ratio > 1 (OR 2.015, 95% CI: 1.042-3.893, p = 0.037) were associated with Ih PE-related death in women. Conclusion. In women, MCTPA parameters, a centrally placed thrombus, the RV/LV ratio, and the EBSS had prognostic significance for PE-related mortality. The RV/LV ratio had prognostic significance for all-cause Ih mortality. In men, the MCTPA parameters had no prognostic significance for both overall and PE-related mortality.

Subsegmental Pulmonary Embolism.

Subsegmental pulmonary embolism (SSPE) is increasingly diagnosed with the growing use and technological advancements of multidetector computed tomography pulmonary angiography. Its diagnosis is challenging, and some presumed SSPE may actually represent imaging artifacts. Indirect evidence and results from small observational studies suggest that SSPE may be more benign than more proximal pulmonary embolism, and may thus not always require treatment. Therefore, guidelines suggest to consider a management strategy without anticoagulation in selected patients with SSPE at low risk of recurrent venous thromboembolism (VTE), in whom proximal deep vein thrombosis is excluded. Recently, a large prospective study among low-risk patients with SSPE who were left untreated showed a higher VTE recurrence risk than initially deemed acceptable by the investigators, and thus was prematurely interrupted after recruitment of 97% of the target population. However, the risk-benefit ratio of anticoagulation for low-risk patients with SSPE remains unclear, and results from randomized trials are needed to answer the question about their optimal management.

Predictive value of admission glycemia in diabetics with pulmonary embolism compared to non-diabetic patients.

To examine the relationship between admission glucose (AG) level and short-term in-hospital mortality and to investigate the association between hyperglycemia and major bleeding in PE patients with and without DMT2. We evaluated 1165 patients with diagnosed acute PE with multi-detector computed tomography pulmonary angiography (MDCT-PA) enrolled in the Regional multicenter PE registry (REPER). The study population was classified to patients with diabetes mellitus type 2 (DMT2) and those without diabetes. According to quartiles of AG patients, both groups separately were categorized into four subgroups (DMT2 I: < 7.5mmol/L; II: 7.5-10.0mmol/L; III: 10.0-15.7mmol/L; IV: > 15.7mmol/L and (non-DMT2 I: < 5.5mmol/L; II: 5.5-6.3mmol/L; III: 6.3-7.9mmol/L; IV: > 7.9mmol/L). All-cause mortality was higher in the DMT2 group (9.5% vs. 18.2%, p < 0.001), and PE-cause mortality was 6% for the patients without DMT2 and 12.4% for DMT2 patients (p = 0.02). The patients in the fourth AG quartiles in both groups, without DMT2 and with DMT2, had significantly higher all-cause and PE-cause in-hospital mortality compared with the first quartile. Rates of major bleeding were similar between the groups. On the multivariable analysis, after adjusting for age, gender and mortality risk, the adherence in the fourth AG quartile had an independent predictive value for all-cause death (HR 2.476, 95% CI 1.017-6.027) only in DM patients. In our cohort of patients with acute PE, diabetes was associated with increased rates for all-cause and PE-cause mortality.

CECT in Pulmonary Thrombolism

Introduction: Pulmonary embolism (PE) is the third most common acute heart disease after myocardial infarction and stroke and is a major public health problem. PE is a disease that has high morbidity and mortality, yet it is challenging to obtain a diagnosis.&#x0D; Objective: The study aims to assess the role of MDCT-PA in the diagnosis of pulmonary embolism, and it's associated conditions in suspected cases of pulmonary embolism.&#x0D; Materials and Methods: The study was conducted in the department of radiology in KRISHNA INSTITUTE OF MEDICAL SCIENCES DEEMED TO BE UNIVERSITY situated in KARAD equipped with a 16 slice MDCT scanner (EMOTION) manufactured by Siemens.&#x0D; Results: Through the study period of one and half year and have met the inclusion criteria, a total of 90 consecutive patients who presented with suspicion of PE were referred for MDCT-PA in the department of radio-diagnosis, Krishna Hospital, Karad. A review of all the cases was done, and the results were presented in the form of tables.&#x0D; Conclusion: Multidetector computed tomography pulmonary angiography can be used to confidently diagnose pulmonary embolism in which it is not contraindicated. MDCT-PA is the investigation of choice because it is a rapid, non-invasive study, highly sensitive and specific.

Frequency of computed tomography abnormalities in patients with chronic thromboembolic pulmonary hypertension: a comparative study between lung perfusion scan and computed tomography pulmonary angiography.

IntroductionChronic thromboembolic pulmonary hypertension (CTEPH) is one of the leading causes of pulmonary hypertension. Diagnosis of CTEPH can be established using various imaging techniques, including ventilation-perfusion scintigraphy (VQ) and multidetector computed tomography pulmonary angiography (CTPA). The aim of this study was to determine the frequency of direct pulmonary vascular, parenchymal lung, and cardiac abnormalities on CTPA in patients with CTEPH and to compare the diagnostic accuracy of both VQ scan CTPA in detecting CTEPH.MethodsWe retrospectively included 54 patients who had been referred for pulmonary hypertension service (20 males, 34 females). All patients had VQ scan and CTPA within 15 days and underwent pulmonary artery endarterectomy (PEA) thereafter. VQ scans were reported according to modified PIOPED (Prospective Investigation of Pulmonary Embolism Diagnosis) criteria. CTPA was considered as diagnostic for CTEPH if it showed presence of thrombus, webs, stenosis, or perfusion lung abnormalities.ResultsThe mean age of the study population was 41±10 years. The mean pulmonary artery pressure was 53±13 mmHg. Fifty-three out of 54 patients in the study population had high probability VQ scan and one patient had intermediate probability. CTPA was suggestive of CTEPH in all patients. The most frequent CTPA findings in the central pulmonary arteries and peripheral arteries were presence of thrombotic materials, abnormal vessel tapering and abrupt vessels-cut off (76% vs 65%, 67% vs 48%, and 48% vs 22%), respectively. The mosaic lung perfusion was present in 78% of the patients, and various cardiac morphology abnormalities were present and most common was abnormal right to left ventricle ratio (69%).ConclusionOur findings indicate that both VQ scan and CTPA are highly sensitive for the detection of CTEPH confirmed by PEA. Most CTEPH patients had several pulmonary vascular, parenchymal lung and cardiac abnormalities. There was no sign with 100% sensitivity on CTPA for CTEPH detection.

Radiological analysis of acute pulmonary thromboembolism as a consequence of COVID-19: A case report

SARS-CoV-2 is a virus of the coronavidae family that causes COVID-19, a disease that emerged in 2019 and has already gone around the world, causing the World Health Organization to decree a pandemic state in 2020. One of the consequences of COVID-19 is the development of Pulmonary Thromboembolism (PE), a disease in which one or more pulmonary arteries are blocked by a blood clot. In this association with COVID-19, PE is caused by the pro-inflammatory and hypercoagulant state developed by the SARS-CoV-2 infection. To analyze aspects of both diseases, imaging tests such as computed tomography (CT) and chest radiography (X-ray) are commonly used. CT and X-ray are considered first-line imaging tools to assess the decline in cases of COVID-19, and besides that, multidetector CT pulmonary angiography (CTPA) can assist in the confirmation or exclusion of PE. Therefore, this case report is about imaging findings that correlate COVID-19 and PE.

Association of computed tomography pulmonary angiography findings with clinical outcome in patients with acute pulmonary embolism

Context: Acute pulmonary embolism (PE) is one of the common and potentially fatal medical emergencies. The short-term mortality of PE ranges from less than 1% in hemodynamically stable patients to over 90% in patients presenting with cardiopulmonary arrest.[1] Patients presenting with PE have a high risk of mortality in the first 30 days.[2],[3],[4],[5] Echocardiography is routinely done in cases of PE for knowing cardiac status but echo being highly operator dependent, Computed Tomography (CT) pulmonary angiography (CTPA) can provide an alternative with lesser operator dependence. The main purpose of this study is to assess the prognostic value of different parameters measured by multi-detector CT pulmonary angiography (CTPA) in evaluating the clinical outcome of acute PE patients.Aim and Objectives: To study association of left atrium (LA) volume, LA volume index, RVV/LVV ratio, IVC reflux, interventricular septal bowing with clinical outcome.Methods and Materials: The prospective study was conducted in the Department of Radio-Diagnosis, Sri Venkateswara Institute of Medical Sciences (SVIMS), Tirupati in the time frame of March 2018 to June 2019. A total of 46 cases that were confirmed to have acute pulmonary thromboembolism on CTPA meeting the study criteria were studied for location of emboli, LA volume, LA volume index, RVV/LVV ratio, IVC reflux, interventricular septal bowing. The parameters were compared with adverse clinical outcomes which were defined as death within 30 days or escalation of therapy, according to the MAPPET-3 ( Management Strategies and Prognosis in Pulmonary Embolism Trial-3) study criteria.[7]Statistical Analysis Used: Chi-square test was used for comparisons of categorical variables, and Student t-test was used for comparisons in the distributions of continuous variables by using IBM SPSS statistics 20. A P value <0.05 was considered significant.Results: Our study included 46 patients belonging to age range of 18 to 83 years with evidence of pulmonary thromboembolism on CTPA study. Out of these, 18 (39%) patients had adverse events, where 17 (37%) patients died within 30 days, and 1 (2%) had a cardiac arrest where he was revived after cardiopulmonary resuscitation within 30 days from diagnosis of acute PE. There was no difference in the distribution of age, sex or other comorbidities between the patients who had adverse events and those who did not. In our study, patients with centrally lodged thrombi showed higher mortality and other adverse events than patients with more peripherally lodged PE (p value = 0.022). There was no evidence of any statistically significant association between the IVC reflux, septal bowing, cardiac volume parameters with adverse events within 30 days of diagnosis of acute PE.Conclusion: In our study, we found the location of thrombus on CTPA to be a significant factor in predicting the adverse outcome. Other parameters like LA volume, LA volume index, RVV/LVV ratio, IVC reflux interventricular septal bowing did not demonstrate a significant relationship with 30-day adverse outcomes. The use of cardiac volumes in predicting the clinical outcome did not show any significant relationship, and this could be due to underlying conditions like hypertension, smoking, systemic diseases. The use of cardiac chamber volumes in predicting clinical outcome needs to be studied on a larger sample size to look for the role of other systemic factors affecting its volume.

Incidence of pulmonary embolism in non-critically ill COVID-19 patients. Predicting factors for a challenging diagnosis.

Recent studies suggest that thrombotic complications are a common phenomenon in the novel SARS-CoV-2 infection. The main objective of our study is to assess cumulative incidence of pulmonary embolism (PE) in non critically ill COVID-19 patients and to identify its predicting factors associated to the diagnosis of pulmonary embolism. We retrospectevely reviewed 452 electronic medical records of patients admitted to Internal Medicine Department of a secondary hospital in Madrid during Covid 19 pandemic outbreak. We included 91 patients who underwent a multidetector Computed Tomography pulmonary angiography(CTPA) during conventional hospitalization. The cumulative incidence of PE was assessed ant the clinical, analytical and radiological characteristics were compared between patients with and without PE. PE incidence was 6.4% (29/452 patients). Most patients with a confirmed diagnosed with PE recieved low molecular weight heparin (LMWH): 79.3% (23/29). D-dimer peak was significatly elevated in PE vs non PE patients (14,480 vs 7230 mcg/dL, p = 0.03). In multivariate analysis of patients who underwent a CTPA we found that plasma D-dimer peak was an independen predictor of PE with a best cut off point of > 5000 µg/dl (OR 3.77; IC95% (1.18–12.16), p = 0.03). We found ninefold increased risk of PE patients not suffering from dyslipidemia (OR 9.06; IC95% (1.88–43.60). Predictive value of AUC for ROC is 75.5%. We found a high incidence of PE in non critically ill hospitalized COVID 19 patients despite standard thromboprophylaxis. An increase in D-dimer levels is an independent predictor for PE, with a best cut-off point of > 5000 µg/ dl.

Advances in the Diagnosis of Venous Thromboembolism: A Literature Review.

The incidence of venous thromboembolism (VTE), including lower extremity deep vein thrombosis (DVT) and pulmonary embolism (PE) is increasing. The increase in suspicion for VTE has lowered the threshold for performing imaging studies to confirm diagnosis of VTE. However, only 20% of suspected cases have a confirmed diagnosis of VTE. Development of pulmonary embolism rule-out criteria (PERC) and update in pre-test probability have changed the paradigm of ruling-out patient with low index of suspicion. The D-dimer test in conjunction to the pre-test probability has been utilized in VTE diagnosis. The age appropriate D-dimer cutoff and inclusion of YEARS algorithm (signs of the DVT, hemoptysis and whether PE is the likely diagnosis) for the D-dimer cutoff have been recent updates in the evaluation of suspected PE. Multi-detector computed tomography pulmonary angiography (CTPA) and compression ultrasound (CUS) are the preferred imaging modality to diagnose PE and DVT respectively. The VTE diagnostic algorithm do differ in pregnant individuals. The prerequisite of avoiding excessive radiation has recruited planar ventilation-perfusion (V/Q) scan as preferred in pregnant patients to evaluate for PE. The modification of CUS protocol with addition of the Valsalva maneuver should be performed while evaluating DVT in pregnant individual.

Outcomes of Multidetector Computed Tomography Pulmonary Angiography in Pregnant and Postpartum Women With Suspected Pulmonary Embolism.

Verify whether there is a difference in likelihood of developing pulmonary embolism (PE) between pregnant women, nonpregnant women of reproductive age, and postpartum (up to 6 weeks) women, by comparing their outcomes on computed tomography pulmonary angiography (CTPA) done for suspicion of PE. Retrospective cohort study of 1463 CTPA done for suspicion of PE in females of reproductive age (18-40 years), nonpregnant, pregnant (antepartum), and postpartum, from 2 tertiary-care academic hospitals between October 2006 and September 2015. Primary outcome was diagnosis of PE on imaging. Additional assessment was made of technical adequacy of the studies and method of delivery for the postpartum cohort (vaginal vs caesarean birth). Twenty-nine technically nondiagnostic studies were excluded. The effect of any potential variable on PE status was tested using univariate logistic regression. Subgroup analysis was performed after excluding patients with independent risk factors for PE. The rate of CTPA positive for PE was less among pregnant patients compared to early postpartum and nonpregnant women of similar age, 2.9% vs 11.5% and 10.3%, respectively. Pregnancy was associated with statistically significant decreased odds ratio of developing a PE on CTPA, 0.23 (0.09-0.89), P value = .004. After excluding patients with additional independent risk factors for PE, there was no statistically significant odds ratio association between presence of PE on CTPA and pregnancy 0.41 (0.13-1.34), P value = .14. Rate of CTPA positive for PE in pregnant women was lower than in nonpregnant and early postpartum women. Pregnancy was statistically significantly less likely to be associated with positive PE on a CTPA study. The common perception that pregnancy (antepartum state) is associated with an increased risk of PE may require a thorough critical reappraisal.

Does dual-energy computed tomography pulmonary angiography (CTPA) have improved image quality over routine single-energy CTPA?

The aim of this study is to compare the diagnostic sensitivity between dual-energy computed tomography pulmonary angiography (CTPA) studies and routine single-energy CTPA studies. A total of 117 patients with clinically suspected pulmonary embolism were examined with dual-energy CTPA (DECT) and reformatted single-energy multidetector CTPA (MDCT) studies. Two independent radiologists assessed the image quality of the CTPAs with objective and subjective parameters, including by assigning an image quality score out of 10 for each study. Dose length product and effective dose were also calculated and compared. The subjective image quality score for DECT and MDCT studies was 9.19 and 7.88, respectively; however, the increased level of detail in DECT may not be clinically applicable. Pulmonary artery filling defects were found in 12 patients, with no subjective diagnostic differences between dual-energy or single-energy studies with either radiologist. The effective dose for DECT ranged from 1.8 to 7.8 mSv. The effective dose for MDCT ranged from 1.2 to 6.4 mSv. Radiologists are trained to look at routine MDCTs with high specificity and sensitivity. DECTs do not appear to offer trained radiologists improved detection of clinically relevant pulmonary emboli.

A Clinically Meaningful Interpretation of the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) II and III Data

This study aimed to calculate the multiple-level likelihood ratios (LRs) and posttest probabilities for a positive, indeterminate, or negative test result for multidetector computed tomography pulmonary angiography (MDCTPA) ± computed tomography venography (CTV) and magnetic resonance pulmonary angiography (MRPA) ± magnetic resonance venography (MRV) for each clinical probability level (two-, three-, and four-level) for the nine most commonly used clinical prediction rules (CPRs) (Wells, Geneva, Miniati, and Charlotte). The study design is a review of observational studies with critical review of multiple cohort studies. The settings are acute care, emergency room care, and ambulatory care (inpatients and outpatients). Data were used to estimate pulmonary embolism (PE) pretest probability for each of the most commonly used CPRs at each probability level. Multiple-level LRs (positive, indeterminate, negative test) were generated and used to calculate posttest probabilities for MDCTPA, MDCTPA + CTV, MRPA, and MRPA + MRV from sensitivity and specificity results from Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) II and PIOPED III for each clinical probability level for each CPR. Nomograms were also created. The LRs for a positive test result were higher for MRPA compared to MDCTPA without venography (76 vs 20) and with venography (42 vs 18). LRs for a negative test result were lower for MDCTPA compared to MRPA without venography (0.18 vs 0.22) and with venography (0.12 vs 0.15). In the three-level Wells score, the pretest clinical probability of PE for a low, moderate, and high clinical probability score is 5.7, 23, and 49. The posttest probability for an initially low clinical probability PE for a positive, indeterminate, and negative test result, respectively, for MDCTPA is 54, 5 and 1; for MDCTPA + CTV is 52, 2, and 0.7; for MRPA is 82, 6, and 1; and for MRPA + MRV is 72, 3, and 1; for an initially moderate clinical probability PE for MDCTPA is 86, 22, and 5; for MDCTPA + CTV is 85, 10, and 4; for MRPA is 96, 25, and 6; and for MRPA + MRV is 93, 14, and 4; and for an initially high clinical probability of PE for MDCTPA is 95, 47, and 15; for MDCTPA + CTV is 95, 27, and 10; for MRPA is 99, 52, and 17; and for MRPA + MRV is 98, 34, and 13. For a positive test result, LRs were considerably higher for MRPA compared to MDCTPA. However, both a positive MRPA and MDCTPA have LRs >10 and therefore can confirm the presence of PE. Performing venography reduced the LR for a positive and negative test for both MDCTPA and MRPA. The nomograms give posttest probabilities for a positive, indeterminate, or negative test result for MDCTPA and MRPA (with and without venography) for each clinical probability level for each of the CPR.

Different modalities in diagnosis of thrombotic pulmonary embolism: a hospital-based study

Background Pulmonary embolism (PE) is a potentially life-threatening cardiovascular emergency with a high mortality rate; PE is a difficult diagnosis that may be missed because of nonspecific clinical presentation. However, multidetector computed tomography pulmonary angiography (MDCT-PA) is considered the gold standard in diagnosis. D-Dimer has high sensitivity to PE that if negative and clinical probability is low PE can safely be excluded without the need for further investigation. Objective The aim of this study was to evaluate demographic data, clinical, radiographic, and laboratory findings in patients with PE and the relationship of those findings with the embolism location, and the reason for severity of the embolism. Patients and methods This study was conducted on 100 patients diagnosed with PE based on MDCT-PA at Chest Diseases Department of Al-Azhar Assiut and Assiut University Hospitals, Egypt, from May 2013 to December 2015. All patients were subjected to complete history taking, clinical examination, routine investigations, D-dimer, O2 saturation, arterial blood gases, ECG, Doppler ultrasound, chest radiography, MDCT-PA for all patients, and echocardiography in selected patients. Results There were significant differences between D-dimer from one hand and severity of PE, and also the site and extent of the embolus from the other hand, as D-dimer levels were higher in massive than submassive PE, and in main pulmonary artery embolus than segmental branches, and lastly subsegmental branches. ECG findings in PE were nonspecific but could aid in the diagnosis. The most common findings were sinus tachycardia followed by inverted T wave in anterior chest leads, whereas the typical S1Q3T3 was less common. Conclusion A practical and evidence-based approach is to combine a D-dimer result with a validated clinical risk score to help selection of suitable patients for computed tomography pulmonary angiogram. Recommendation A clinical probability assessment and D-dimer value should be combined and used to quantify the patient’s risk of PE as low, moderate, or high.

Safety of multidetector computed tomography pulmonary angiography to exclude pulmonary embolism in patients with a likely pretest clinical probability

Background In patients with suspected pulmonary embolism (PE) classified as having a likely or high pretest clinical probability, the need to perform additional testing after a negative multidetector computed tomography pulmonary angiography (CTPA) finding remains a matter of debate. Objectives To assess the safety of excluding PE by CTPA without additional imaging in patients with a likely pretest probability of PE. Patients/Methods We retrospectively analyzed patients included in two multicenter management outcome studies that assessed diagnostic algorithms for PE diagnosis. Results Two thousand five hundred and twenty-two outpatients with suspected PE were available for analysis. Of these 2522 patients, 845 had a likely clinical probability as assessed by use of the simplified revised Geneva score. Of all of these patients, 314 had the diagnosis of PE excluded by a negative CTPA finding alone without additional testing, and were left without anticoagulant treatment and followed up for 3 months. Two patients presented with a venous thromboembolism (VTE) during follow-up. Therefore, the 3-month VTE risk in likely-probability patients after a negative CTPA finding alone was 2/314 (0.6%; 95% confidence interval [CI] 0.2-2.3%). Conclusions In outpatients with suspected PE and a likely clinical probability as assessed by use of the simplified revised Geneva score, CTPA alone seems to be able to safely exclude PE, with a low 3-month VTE rate, which is similar to the VTE rate following the gold standard, i.e. pulmonary angiography.

Behçet’s disease: Spectrum of MDCT chest and pulmonary angiography findings in patients with chest complaints

ObjectiveThe aim of the work was directed to evaluate the value of multi-detector computed tomography pulmonary angiography study in evaluation of known patients with Behcet’s disease. Materials and methodsThis study was done retrospectively and included eighteen known patients with Behcet’s disease and referred for MDCT pulmonary angiography. ResultsPulmonary artery aneurysm was the most common finding as it was found in 16 patients, followed by pulmonary embolism which was found in 14 patients, 12 patients with pulmonary hypertension, right ventricular strain in 6 patients, intracardiac thrombus in 4 patients, dilated bronchial arteries in 8 patients, venous occlusion in 4 patients, mosaic attenuation of the lung in 12 patients, pulmonary infarcts in 4 patients, and pleural effusion in 4 patients. ConclusionMDCT pulmonary angiography is an important diagnostic imaging tool for diagnosis of vascular complications in patients with Behcet’s disease.

Association of different electrocardiographic patterns with shock index, right ventricle systolic pressure and diameter, and embolic burden score in pulmonary embolism.

Some electrocardiographic (ECG) patterns are characteristic for pulmonary embolism but exact meaning of the different ECG signs are not well known. The aim of this study was to determine the association between four common ECG signs in pulmonary embolism [complete or incomplete right bundle branch block (RBBB), S-waves in the aVL lead, S1Q3T3 sign and negative T-waves in the precordial leads] with shock index (SI), right ventricle diastolic diameter (RVDD) and peak systolic pressure (RVSP) and embolic burden score (EBS). The presence of complete or incomplete RBBB, S waves in aVL lead, S1Q3T3 sign and negative T-waves in the precordial leads were determined at admission ECG in 130 consecutive patients admitted to the intensive care unit of a single tertiary medical center in a 5-year period. Echocardiography examination with measurement of RVDD and RVSP, multidetector computed tomography pulmonary angiography (MDCT-PA) with the calculation of EBS and SI was determined during the admission process. Multivariable regression models were calculated with ECG parameters as independent variables and the mentioned ultrasound, MDCT-PA parameters and SI as dependent variables. The presence of S-waves in the aVL was the only independent predictor of RVDD (F = 39.430, p < 0.001; adjusted R2 = 0.231) and systolic peak right ventricle pressure (F = 29.903, p < 0.001; adjusted R2 = 0.185). Negative T-waves in precordial leads were the only independent predictor for EBS (F = 24.177, p < 0.001; R2 = 0.160). Complete or incomplete RBBB was the independent predictor of SI (F = 20.980, p < 0.001; adjusted R2 = 0.134). In patients with pulmonary embolism different ECG patterns at admission correlate with different clinical, ultrasound and MDCT-PA parameters. RBBB is associated with shock, Swave in the aVL is associated with right ventricle pressure and negative T-waves with the thrombus burden in the pulmonary tree.

Multidetector computed tomography pulmonary angiography in childhood acute pulmonary embolism.

Pulmonary embolism is a life-threatening condition affecting people of all ages. Multidetector row CT pulmonary angiography has improved the imaging of pulmonary embolism in both adults and children and is now regarded as the routine modality for detection of pulmonary embolism. Advanced CT pulmonary angiography techniques developed in recent years, such as dual-energy CT, have been applied as a one-stop modality for pulmonary embolism diagnosis in children, as they can simultaneously provide anatomical and functional information. We discuss CT pulmonary angiography techniques, common and uncommon findings of pulmonary embolism in both conventional and dual-energy CT pulmonary angiography, and radiation dose considerations.

Multidetector Computed Tomography Pulmonary Angiography Pitfalls in the Evaluation of Pulmonary Embolism With Emphasis in Technique

Pulmonary embolism (PE) is considered the third most common acute cardiovascular disease after myocardial infarction and stroke.Most preventable deaths associatedwith PE can be attributed to missed diagnosis, rather than therapy failure; thus, accurate and fast diagnosis of PE is important and greatly influences patient outcome. Computed tomography pulmonary angiography (CTPA) was first introduced as a diagnostic test for PEwith the arrival of helical CT scanners in the early 1990s. Less than a decade later, with improvements in resolution, acquisition speed, and image quality, multidetector CTPA (MDCTPA) became the most used diagnostic modality in the evaluation of PE. In 2007, the Fleischner Society declared that MDCTPA had fulfilled the conditions to replace conventional pulmonary angiography as the standard of reference for diagnosing acute PE. The recent introduction of dual-source MDCT technology adds functional assessment to the established anatomical evaluation, potentially further enhancing the capability of CTPA to determine the presence and clinical significance of pulmonary thromboembolism. The sensitivity and specificity for the diagnosis of PE since the era of single-slice helical CTPA has improved from 53%91% and 78%-97%, respectively, to 83%-100% and 89%97%, respectively, with MDCTPA. Several studies on single-slice and early-generation MDCTPA have reported “indeterminate” results ranging from 0.5%-10%, with a mean at approximately 6%. In a more recent study with 40-slice MDCT, 3.2% of 220 consecutive reports were deemed