Computed Tomography Pulmonary Angiography Results Research Articles

Could the YEARS algorithm be applied to evaluate suspected pulmonary embolism in hospitalized women after cesarean section?

To evaluate the effectiveness of the YEARS algorithm for excluding pulmonary embolism (PE) in hospitalized women after cesarean section. This retrospective study included postpartum women who gave birth by cesarean section and received computed tomography pulmonary angiography (CTPA) because of suspected PE in the obstetric department between 2015 and 2021. We used the YEARS algorithm in these women retrospectively and assessed its performance to evaluate whether the algorithm could be reliably applied in such cases. In all, 225 women were included in the study, of whom 29 (12.9%) women were positive for PE according to the results of CTPA. Upon retrospective application of the YEARS algorithm, 188 (83.6%) women had no YEARS items, while 37 (16.4%) women had YEARS items. Combining the results with D-dimer levels revealed that only 12 (5.3%) women did not need to undergo CTPA, and none showed PE. The YEARS algorithm could be applied to exclude PE in hospitalized women in the early post-cesarean period. However, the specificity of the YEARS algorithm was very low, and the D-dimer cut-off for ruling out PE in women after early cesarean section should be further studied and optimized.

Abstract 14932: Prediction of Pulmonary Embolism Using Random Forest Algorithm: A Study on 917 Patients Over a Period of 1 Year in a New York City Public Hospital

Introduction: Pulmonary Embolism (PE) can be challenging to diagnose. Artificial intelligence (AI)-generated models can help improve the diagnostic accuracy of detecting PE. Aim: Establish the diagnostic accuracy of AI-generated models in predicting PE as compared to routinely used diagnostic predictive tools (Well’s score, YEARS score, and revised Geneva score). Methods: We conducted a single-center retrospective review of patients who underwent computed tomography pulmonary angiography (CTPA) for diagnosing PE over a one-year period. Twenty-five parameters including age, sex, race, BMI, history of deep vein thrombosis or PE, malignancy, hypertension, COPD, CKD, presenting symptoms like chest pain, dyspnea, cough, palpitations, dizziness, lightheadedness/syncope, hemoptysis, fever, pain on palpation of the lower extremity, vitals including heart rate, respiratory rate, oxygen saturation, findings of lower extremity venous duplex, presence of right ventricular dysfunction on echocardiogram, elevated troponin and pro-brain natriuretic peptide were utilized to train the AI model. Random forest algorithms were trained for predicting PE in 80% of the dataset, while the remaining 20% was used to test the AI model. Subsequently, the accuracy of the model was matched with the accuracy of four alternative modalities: clinical judgment of PE being equally or more likely, Well’s score >4, YEARS score ≥1, and revised Geneva score ≥11. CTPA results were used as the gold standard. Analysis was performed using STATA BE/17 and Python 3.8. Results: 917 patients were included in the analysis (median age: 57 years (IQR: 41-68); female: 59%). The AI model correctly classified patients with 84.6% diagnostic accuracy, outperforming every other modality (Figure 1). Conclusion: AI-generated prediction models can be useful in predicting PE with considerable accuracy. Further, large-scale studies are required to validate these results externally.

Diagnostic Yield of CT Pulmonary Angiogram in the Diagnosis of Pulmonary Embolism and Its Predictive Factors.

Introduction Computed tomography pulmonary angiography (CTPA) is the reference investigation of choice to diagnose pulmonary embolism (PE). Nevertheless, the use of CTPA should be weighed against its risks, such as radiation and contrast-induced nephropathy. We aim to assess the yield of CTPA in diagnosing PE at a tertiary centre in Malaysia. We also identify predictive factors associated with the yield of CTPA in this cohort. Methods This was a cross-sectional study involving all patients who had had CTPA done at Hospital Tengku Ampuan Afzan, Kuantan, Malaysia, from January 1, 2021, to November 30, 2021. All patients' records were retrieved and reviewed. CTPA images were retrieved from the Radiology Information System (RIS) and Picture Archiving and Communication System (PACS). They were double-reviewed by the authors, with the initial reports redacted from reporting radiologists to prevent reporting bias. The predictive factors were determined using simple logistic regression and multiple logistic regression. Results A total of 351 CTPAs were reviewed, of which 93 were found to be positive for PE, giving rise to an overall CTPA yield of 26.5%. Upon simple logistic regression, factors such as gender, discipline, history of trauma, presence of COVID-19 infection, and pneumonia were found to be associated with positive CTPA. Upon multiple logistic regression, male patients were found to have a higher chance of positive CTPA results. On the other hand, patients with COVID-19 infection and pneumonia have a lower chance of positive results in CTPA. Conclusion The yield of CTPA in diagnosing PE at our institution was acceptable at 26.5%. Upon multiple logistic regression, patients with COVID-19 infection and pneumonia were more likely to have a negative CTPA result, highlighting the need for clinicians to be more prudent in requesting CTPAs in these patients.

Low concordance between CTPA and echocardiography in identification of right ventricular strain in PERT patients with acute pulmonary embolism.

Right ventricular strain (RVS) is used to risk stratify patients with acute pulmonary embolism (PE) and influence treatment decisions. Guidelines suggest that either computed tomography pulmonary angiography (CTPA) or transthoracic echocardiography (TTE) can be used to assess RVS. We sought to determine how often CTPA and TTE yield discordant results and to assess the test characteristics of CTPA compared to TTE. We analyzed data from a single-center registry of PE cases severe enough to warrant activation of the hospital's Pulmonary Embolism Response Team (PERT). We defined RVS as a right ventricular to left ventricular ratio (RV/LV) ≥ 1 or radiologist's interpretation of RVS on CTPA or as the presence of either RV dilation, hypokinesis, or septal bowing on TTE. We included 554 patients in our analysis, of whom 333 (60%) had concordant RVS findings on CTPA and TTE. Using TTE as the reference standard, CTPA had a sensitivity of 95% (95% CI 92-97%) and a specificity of 4% (95% CI 2-8%) for identifying RVS. In a selected population of patients with acute PE for which PERT was activated, CTPA is highly sensitive but not specific for the detection of RVS when compared to TTE.

Pulmonary Embolism in Childhood: A Multicenter Experience from Turkey

Background:Pulmonary embolism is a clinical condition caused by the obstruction of the pulmonary artery and its branches with endogenous, exogenous embolism, or local thrombus formation. It is a rare but potentially life-threatening event in the pediatric population. Pediatric pulmonary embolism has many unknown characteristics.Aims:To evaluate clinical features, genetic and acquired risk factors, diagnostic imaging, and treatment strategies with long-term results in children with pulmonary embolism.Study Design:A retrospective multicenter clinical trial.Methods:Patients aged 0-18 years who were diagnosed with pulmonary embolism with computed tomography pulmonary angiography (CTPA) findings (intraluminal filling defect in the lobar or main pulmonary artery) in 3 university hospitals between 2006 and 2021 were included in the study. A form was created for data standardization, and variables were collected retrospectively through medical record review. In addition to the features given above, we also evaluated in situ pulmonary artery thrombosis (ISPAT) and patients’ Wells scores. Follow-up CTPA results were evaluated for patient response to treatment. Complete recovery means that there were no lesions, incomplete recovery if there was still embolism, and no response if there was no change.Results:Twenty-four patients (female:13, male:11) were included in the study. The mean age was 13.5 years. All patients but one had at least one or more genetic or acquired risk factors. Factor V Leiden mutation (16.6%) was the most common genetic risk factor. Six of 16 patients with Doppler ultrasonography were diagnosed with ISPAT because there was no sign of thromboembolic thrombosis. Nine (41.6%) patients had a Wells score of >4 (pulmonary embolism clinically strong), and 15 (58.4%) patients scored <4 (pulmonary embolism clinically likely weak), indicating that an alternative diagnosis was more likely than pulmonary embolism (sensitivity %37.5). The mean follow-up period was 23 (±17) months. Complete and incomplete recovery was observed in 15 (62.5%) and 7 (29.1%) patients, respectively, among the patients who underwent follow-up evaluation. No response was obtained in 2 patients (8.3%) who died.Conclusion:The Wells scoring system seems insufficient to diagnose pulmonary embolism in children and should be improved by adding new parameters. ISPAT may be more common in children with congenital heart disease and systemic disease.

The Effect of a Pandemic on Computed Tomography Pulmonary Angiography Results and Utilize in the Emergency Department

Objective: The incidence of pulmonary embolism (PE) increases with COVID-19. With the pandemic, changes occur in the utilization of computed tomography pulmonary angiography (CTPA), which we use in the diagnosis of PE. In our study, we investigated the impact of the pandemic on the utilized and result of CTPA.&#x0D; Methods: Patients over the age of 18 who applied to the emergency department between 01.03.2019 and 28.02.2021 and underwent CTPA was included in this retrospective study. Patients were separated to two groups based on the date of the first case. CTPA result and Polymerase chain reaction (PCR) positivity status were recorded. Data were compared between groups.&#x0D; Results: While 757(1.022%) out of 74,063 patients underwent CTPA in the pre-pandemic period, 649(1.430%) out of 45,397 patients underwent CTPA in the during-pandemic period. The PE rate in patients who underwent CTPA in the during-pandemic period was statistically significantly&#x0D; higher compared to the pre-pandemic period (pre-pandemic: 89(11.9%), during-pandemic: 122(19%), p

Evaluating the performance of unenhanced computed tomography in the diagnosis of pulmonary embolism

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary embolism (PE) is the third most common cardiovascular pathology after coronary artery disease and stroke with an incidence rate of 1 per 1000 individuals. Computed tomography pulmonary angiography (CTPA) as the gold standard examination in the detection of PE is contraindicated or unavailable in certain cases. Purpose The current study aimed to assess the accuracy of unenhanced CT in the diagnosis of PE. Methods A total of 195 consecutive participants with clinical suspicion for PE were enrolled in this prospective cohort study between October 2020 and March 2021. All patients were examined with a 16 slice multidetector (MD) CT scanner before performing the CTPA. Scans were independently reviewed by two expert radiologists who were blinded to patients’ clinical and laboratory history for imaging variables including presence and location of PE, hyper/hypodense intraluminal signs, pulmonary trunk enlargement, peripheral wedge-shaped opacity, and pleural effusion. First unenhanced CT scan and then CTPA were independently reviewed on a picture archiving and communications system workstation. Results There were 82 (42.1%) men and 113 (57.9%) women with the mean age ± standard deviation of 56 ±0.24 years. Based on CTPA results, 47 (24.1%) of 195 patients had PE of which 28 (59.5%) patients had central PE and 19 (40.5%) patients had peripheral PE. However, only 20 cases (42.5%) were detected with PE on MDCT scans consisting of 17 cases with (85%) central emboli and 3 cases with (15%) peripheral emboli. Given intraluminal clot density, 12 (60%) patients had hyperdense signs, 3 (15%) patients had hypodense signs, and 5 (25%) patients had mixed hyper-hypodense signs. There was a significant difference between central and peripheral embolies detected by MDCT. Intraluminal sign had the highest specificity and sensitivity (98.6%, 42.5%, AUC:0.734) followed by pulmonary trunk enlargement (84.4%, 36.1%, AUC: 0.603), peripheral wedge-shaped opacity (72.9%, 34%, AUC: 0.535), and pleural effusion (58.7%, 40.4%, AUC: 0.496). Our results did not show a remarkable difference in secondary findings from the MDCT scan including pulmonary trunk enlargement, peripheral wedge-shaped opacity, and pleural effusion concerning the presence of PE. Pleural effusion as the most common secondary finding in patients with PE was found in 31 (68.8%) of them. Conclusion Unenhanced MDCT has an acceptable performance to detect PE particularly central clots and should be considered as an alternative modality when CTPA is not available or indicated. Furthermore, the intraluminal sign is the main indicator of PE in MDCT images with the highest specificity and sensitivity. We recommend radiologists and other clinicians to be aware of intraluminal signs in case of unexpected PE.

Evaluating the Performance of Unenhanced Computed Tomography in the Diagnosis of Pulmonary Embolism.

Background: Computed tomography pulmonary angiography (CTPA) as the gold-standard examination in the detection of pulmonary embolism (PE) is contraindicated or unavailable in certain cases. The current study aimed to assess the accuracy of unenhanced CT in the diagnosis of PE. Methods: This cohort study was conducted between October 2020 and March 2021 in Birjand, Iran, on 195 participants with clinical suspicion of PE examined with multidetector computed tomography (MDCT) scanning and CTPA. The patients were categorized into 2 groups based on the diagnosis PE in CTPA results. Imaging variables in unenhanced CT scans, including hyper/hypodense intraluminal signs, pulmonary trunk enlargements, peripheral wedge-shaped opacities, and pleural effusions, were independently reviewed by 2 radiologists and then compared between the groups. Results: There were 82 men (42.1%) and 113 women (57.9%) at a mean age ± standard deviation of 56.00±0.24 years. Based on CTPA results, PE was diagnosed in 24.1% of the study population (47/195). However, only 20 cases (42.5%) were detected by MDCT: 17 cases (85.0%) with central PE and 3 cases (15.0%) with peripheral PE. Concerning the intraluminal clot density, 12 patients (60.0%) had hyperdense signs, 3 (15.0%) had hypodense signs, and 5 (25.0%) had mixed hyper/hypodense signs. There was a significant difference between central PE and peripheral PE detected by MDCT. Intraluminal signs had the highest specificity and sensitivity (98.6% and 42.5%, area under the curve =0.734). Conclusion: Unenhanced MDCT has a remarkable performance in detecting PE, specifically central clots, and can, therefore, be considered an alternative modality when CTPA is not available or indicated.

Comparison of Auxiliary Diagnostic Methods in Pulmonary Embolism

Aim: We investigated the importance of auxiliary diagnostic methods in cases when computed tomography pulmonary angiography (CTPA) cannot be used in pulmonary embolism (PE) with a high mortality rate.Materials and Methods: Patients were selected after the exclusion criteria were applied in a sample created from a single center. A total of 86 patients included in our study were examined in terms of clinical features, auxiliary diagnostic methods, anticoagulant use, and hospitalization and discharge status according to the massive or segmental involvement of PE in CTPA.Results: The mean age of the patients was 52.29±14.14 years. According to the CTPA results, there were 46 (53.5%) patients with massive involvement and 40 (46.5%) patients with segmental involvement. While there were 38 (82.6%) patients with massive involvement whose right chambers of the heart were dilated in echocardiography (ECHO) results, there were 19 (47.5%) patients with segmental involvement. There was a statistical significance between the massive involvement of CTPA and ECHO result (p=0.001).Conclusion: ECHO may be preferred as an auxiliary radiological method in the diagnosis of PE in emergency departments (ED), especially in massive embolisms.

Prediction of Mortality Associated with Cardiac and Radiological Findings in Patients with Pulmonary Embolism

Abstract Background: In this study, we aimed to compare echocardiography, electrocardiography (ECG) abnormalities, Doppler ultrasonography (USG), and computed tomography pulmonary angiography (CTPA) results in predicting 3-month mortality in patients with acute pulmonary embolism (PE). Methods: This retrospective cohort study included 124 patients (72 females, 52 males) with acute PE. Demographics, symptoms, clinical signs, comorbidities, history of surgery, arterial blood gas, liver-renal functions, complete blood count, echocardiography, ECG, Doppler USG, and CTPA results, as well as 3-month mortality were recorded. Results: pH (z = –2.623; p &lt;0.01), hemoglobin (z = –3.112; p &lt;0.01), and oxygen saturation (z = –2.165; p &lt;0. 01) were significantly higher in survivors. White blood cell (z = –2.703; p &lt;0.01), blood urea nitrogen (z = –3.840; p &lt;0.01), creatinine (z = –3.200; p &lt;0.01), respiratory rate (z = –2.759; p &lt;0.01), and heart rate (z = –2.313; p &lt;0.01) were significantly higher in non-survivors. Nonspecific ST changes (AUC 0.52, 95% CI 0.43–0.61), p pulmonale (AUC 0.52, 95% CI 0.43–0.61), normal axis (AUC 0.61), right axis deviation (AUC 0.56), right ventricle strain pattern (AUC 0.59), and right pulmonary artery embolism (AUC 0.54) on CTPA showed the highest mortality prediction. Conclusions: Nonspecific ST changes, p pulmonale, normal axis and right axis deviation in ECG, RV strain in echocardiography, and right pulmonary artery embolism on CTPA are associated with a higher mortality in patients with PE.

Predictors of positive computed tomography pulmonary angiography results.

Computed tomography pulmonary angiography (CT-PA) is the diagnostic modality used for pulmonary embolism (PE). This study aimed to estimate the positive CT-PA rate and identify the predictors of positive CT-PA results. A retrospective observational study was conducted by examining the CT-PA data for ruling out PE in all adult patients who visited the King Fahd Hospital of Imam Abdulrahman Bin Faisal University. The data regarding background demographic information, clinical information, and CT-PA findings were collected from electronic health records. Data were analyzed descriptively using the chi-squared test. Multivariate regression analysis was used to identify the predictors of positive CT-PA results. In total, 548 patients (209 male, 339 female) who underwent CT-PA scans were included. The positive CT-PA rate was 18.8%. The Charlson Comorbidity Index was not significantly associated with positive CT-PA results (p = 0.456). Multivariate logistic regression analysis revealed that smoking (odds ratio [OR] 4.96; 95% confidence interval [95% CI] 2.05-12.02) was an independent factor associated with positive CT-PA results. The CT-PA scans performed in winter and spring were 43% (OR 0.43; 95% CI 0.22-0.84) and 52% (OR 0.52; 95% CI 0.28-0.97) less likely to show positive results compared with those performed in autumn, respectively. The positive CT-PA rate varied significantly between seasons. Smoking was a predictor of positive CT-PA results. These findings may assist in developing interventions for improving the utilization of CT-PA scans to avoid unnecessary exposure of patients to radiation. N/A.

Pulmonary Vein Sign on Unenhanced-MRI as a Sign of Severe Pulmonary Embolism

Background: Increased right ventricle-to-left ventricle (RV/LV) ratio on computed tomography pulmonary angiography (CTPA) has been reported as a poor prognostic indicator in patients with acute pulmonary embolism (PE). It has also been reported that pulmonary vein sign (PVS) on CTPA is a rare finding of PE. Objectives: To evaluate PVS on CTPA and unenhanced magnetic resonance imaging (MRI) in patients with PE suspicion. We also aimed to investigate the relationship between the severity of PE and presence of PVS, RV/LV ratio and combination of these two on unenhanced MRI. Patients and Methods: One-hundred-twelve patients with PE suspicion who underwent CTPA and unenhanced-MRI [steady state free precession (SSFP)] within the first 48-hours constituted the study group. All CTPA images were evaluated for the presence, location and severity of PE by observer-1. Two observers (observer-2 and 3), independently evaluated unenhanced-MR images for the presence of PVS without knowing the results of CTPA. Then, these 2 observers reviewed the CTPA and MRI images together with observer-4 to reach the final consensus for the presence of PVS and measurement of RV/LV ratio. Cohen’s Kappa analysis was used to assess the agreement between observers. Relationship between the mean PE index and imaging findings (PVS, RV/LV) were calculated. Results: Presence of PVS on CT or MRI is significantly correlated with PE index and patients with PVS had more severe PE than those without. Presence of both PVS and RV/LV ratio > 1 on MRI indicates more severe pulmonary embolism than absence of PVS or RV/LV ratio > 1. There was a very good agreement for the detection of PVS between two observers on unenhanced MRI. Conclusion: PVS on CTPA or unenhanced MRI can be used as a sign of severe PE and it may also be an indicator of right heart dysfunction.

Diagnosis of Pulmonary Embolism During Pregnancy: A Multicenter Prospective Management Outcome Study.

Data on the optimal diagnostic management of pregnant women with suspected pulmonary embolism (PE) are limited, and guidelines provide inconsistent recommendations on use of diagnostic tests. To prospectively validate a diagnostic strategy in pregnant women with suspected PE. Multicenter, multinational, prospective diagnostic management outcome study involving pretest clinical probability assessment, high-sensitivity D-dimer testing, bilateral lower limb compression ultrasonography (CUS), and computed tomography pulmonary angiography (CTPA). (ClinicalTrials.gov: NCT00740454). 11 centers in France and Switzerland between August 2008 and July 2016. Pregnant women with clinically suspected PE in emergency departments. Pulmonary embolism was excluded in patients with a low or intermediate pretest clinical probability and a negative D-dimer result. All others underwent lower limb CUS and, if results were negative, CTPA. A ventilation-perfusion (V/Q) scan was done if CTPA results were inconclusive. Pulmonary embolism was excluded if results of the diagnostic work-up were negative, and untreated pregnant women had clinical follow-up at 3 months. The primary outcome was the rate of adjudicated venous thromboembolic events during the 3-month follow-up. 441 women were assessed for eligibility, and 395 were included in the study. Among these, PE was diagnosed in 28 (7.1%) (proximal deep venous thrombosis found on ultrasonography [n= 7], positive CTPA result [n= 19], and high-probability V/Q scan [n= 2]) and excluded in 367 (clinical probability and negative D-dimer result [n= 46], negative CTPA result [n= 290], normal or low-probability V/Q scan [n= 17], and other reason [n= 14]). Twenty-two women received extended anticoagulation during follow-up, mainly for previous venous thromboembolic disease. The rate of symptomatic venous thromboembolic events was 0.0% (95% CI, 0.0% to 1.0%) among untreated women after exclusion of PE on the basis of negative results on the diagnostic work-up. There were several protocol deviations, reflecting the difficulty of performing studies in pregnant women with suspected PE. A diagnostic strategy based on assessment of clinical probability, D-dimer measurement, CUS, and CTPA can safely rule out PE in pregnant women. Swiss National Foundation for Scientific Research, Groupe d'Etude de la Thrombose de Bretagne Occidentale, and International Society on Thrombosis and Haemostasis.

Monocyte to large platelet ratio as a diagnostic tool for pulmonary embolism in patients with acute exacerbation of chronic obstructive pulmonary disease.

INTRODUCTION A higher prevalence of pulmonary embolism (PE) has been noted among patients with chronic obstructive pulmonary disease (COPD), particularly in those with acute exacerbations of COPD (AECOPD). Due to a similar clinical presentation and the lack of highly specific laboratory tests, there is a common overuse of computed tomography pulmonary angiography (CTPA). The introduction of an additional, simple, and inexpensive diagnostic tool to help in the diagnosis of PE in patients with AECOPD would be of special interest for everyday clinical practice. OBJECTIVES The aim of the study was to assess the usefulness of the monocyte to large platelet ratio (MLPR) as a diagnostic tool for PE in patients with AECOPD. PATIENTS AND METHODS We performed a retrospective evaluation of patients with AECOPD and suspicion of PE who underwent CTPA. The MLPR was investigated as a marker of thrombosis. Receiver operating characteristics (ROC) curve analyses were preformed to measure the accuracy of the MLPR in comparison with CTPA results and to identify the cutoff value for the MLPR. RESULTS A total of 101 patients (56 men and 45 women; median age, 72 years; range, 37-94 years) were included in the study. The MLPR showed an excellent accuracy in comparison with CTPA results: the area under the ROC curve was 0.945 (95% confidence interval [CI], 0.904-0.986). The MLPR was characterized by a good accuracy of qualitative test parameters, with high sensitivity (100%; 95% CI, 79.6-100) and specificity (85.7%; 95% CI, 75.9-92.6). CONCLUSIONS The MLPR measurement appears to be a reliable, simple, inexpensive, and widely available test that may help in the differential diagnosis of PE in patients with AECOPD.

Underuse of risk assessment and overuse of computed tomography pulmonary angiography in patients with suspected pulmonary thromboembolism.

Evidence suggests the potential overuse of computed tomography pulmonary angiography (CTPA) in patients with suspected pulmonary thromboembolism (PTE) in the absence of consistent use of pre-test clinical prediction rules and D-dimer assays. To evaluate use and diagnostic utility of clinical prediction rules and D-dimer assay in patients with suspected PTE and quantify potentially avoidable overuse of CTPA in low risk patients. A total of 344 consecutive patients undergoing CTPA at a tertiary hospital was studied with regards to the use of D-dimer assays and clinical prediction rules for PTE. For each patient, a modified Wells score (mWS), revised Geneva score and PISA model were calculated retrospectively; performance characteristics for each rule for PTE were determined with reference to results of CTPA. Results for the mWS and D-dimer assays (when performed) were used to estimate the overuse of CTPA according to risk category. Use of a clinical prediction rule was documented in only 5.0% of cases. Of 269 low-risk patients who had a calculated mWS ≤4, only 64 (23.8%) had a D-dimer assay performed, with 30 (11.1%) having a PTE on CTPA. Among 75 patients with an mWS >4, 23 (30.7%) had a PTE on CTPA (P < 0.001). Compared to other prediction rules, an mWS>4 had the highest positive predictive value (31.0%) for PTE; all rules demonstrated similar negative predictive values for low-risk scores (87-89%). After adjusting for an 11% false negative rate for PTE in patients with low-risk mWS, overuse of CTPA was reported in up to 190 (55.2%) patients. More than 50% of patients with suspected PTE may be subject to unwarranted use of CTPA in the absence of pre-test clinical prediction rules coupled with D-dimer assays.

Yield of computed tomography pulmonary angiogram in the emergency department in cancer patients suspected to have pulmonary embolism

Objective/backgroundThe use of computed tomography pulmonary angiography (CTPA) in the emergency department (ED) for patients suspected to have pulmonary embolism (PE) has been steadily rising in the last 2decades. However, there are limited studies that specifically address the use of CTPA in the ED for cancer patients suspected to have PE. The objective of this study is to assess the rate of positive PE by CTPA in the ED in cancer patients and the variables that are associated with positive results. MethodsA retrospective review of electronic medical records for 208 consecutive patients with cancer who presented to the ED and received a CTPA for suspected PE over a 12-month period. The review included demographics, type and status of cancer, presenting symptoms, CTPA results, calculation of Wells Score, management based on CT findings, and outcome of patients. ResultsAmong the 208 patients who met the inclusion criteria during our study period (mean age 57±13.37years, 73% women, 59% African American, and 32% Caucasians), 5.7% were diagnosed with PE. One hundred and eighty-two (83.7%) had a Wells Score ⩽4, of which 2.2% were found to have to have PE, 22 (16.3%) patients had a Wells Score >4, of which 36.4% were found to have PE (p<.0001). Sensitivity and specificity of Wells >4 was 66.7% and 92.9%, respectively, with an odds ratio of 27 (95% CI 6.6–113.6). Receiver operator characteristics area under the curve for Wells Score was 0.868. Age, race, sex, malignancy type, stage, status, clinical presentation, D-dimer, and a previous history of venous thromboembolism were not found to have statistically significant predictive values. ConclusionThe yield of CTPA to rule out PE in patients with cancer presenting in the ED is low. Following a validated decision-making protocol such as Wells Criteria may significantly decrease the number of CTPA used in the ED.

Elevated d-dimer cut-off values for computed tomography pulmonary angiography—d-dimer correlates with location of embolism

Acute pulmonary embolism (APE) is a potentially fatal condition, and making a timely diagnosis can be challenging. Computed tomography pulmonary angiography (CTPA) has become the modality of choice, and this contributes to the increasing load on emergency room CT scanners. Our purpose was to investigate whether an elevated d-dimer cut-off could reduce the demand for CTPA while maintaining a high sensitivity and negative predictive value (NPV). We retrospectively reviewed all patients referred for CTPA with suspicion of APE in 2012, and collected d-dimer values and CTPA results. We investigated the diagnostic performance of d-dimer using a 0.5 mg/L cut-off and an age adjusted cut-off. We also evaluated a new and elevated cut-off. Cases were categorized according to their CTPA result into: no embolism, peripheral embolism, lobar embolism and central embolism. Finally we investigated a possible correlation between d-dimer values and location of embolism. We included 1,051 CTPAs, from which 216 (21%) showed pulmonary embolism. There were concomitant d-dimer analyses in 822 CTPA examinations. The current 0.5 mg/L cut-off achieved a sensitivity and NPV of 99%. The age-adjusted cut-off achieved a sensitivity and NPV of 98%, and our suggested cut-off of 0.9 mg/L achieved a sensitivity and NPV of 97%. We conclude that the elevated d-dimer cut-off of 0.9 mg/L achieved a high sensitivity and NPV, while reducing the number of CTPA by 27%. The correlation between d-dimer values and location of embolisms supports the suggestion of an elevated d-dimer value.

Computed Tomography Pulmonary Angiography for Evaluation of Patients With Suspected Pulmonary Embolism: Use or Overuse.

Background:The use of computed tomography pulmonary angiography (CTPA) has been increased during the last decade.Objectives:We studied the adherence to current diagnostic recommendations for evaluation of pulmonary embolism in a teaching hospital of Tehran University of Medical Sciences.Patients and Methods:The registered medical records (Wells scores and serum D-dimer level) of all patients whose CTPA was performed with suspicion of pulmonary thromboembolism (PTE) were studied retrospectively. Modified Wells score of each patient was determined without being aware of the CTPA results. The patients were categorized to those with a high (likely) clinical probability (score > 4) and low (unlikely) clinical probability (score≤ 4) of PTE.Results:During a 6-month period, 82 patients who underwent CTPA were included. The prevalence of PTE was 62.2% in the group of subjects with a likely clinical risk. In 45 (54.8%) of those patients whose CTPA was requested, the PTE was unlikely based on modified Wells criteria. In the clinically unlikely group, serum D-dimer assay was done in 15 out of 45 (33.3%), while it was inappropriately checked in 10 out of 37 (27.0%) with a clinically likely risk. General adherence rate to diagnostic algorithm of PTE was 43.9%.Conclusion:There is still excessive unjustified concern of PTE in less trained physicians leading to excessive diagnostic work-up. Loyalty to the existing guideline for management of suspected PTE in educational hospitals and supervision of attending physicians could prevent overuse of CTPA.

Incidental Findings in Patients Evaluated for Pulmonary Embolism Using Computed Tomography Angiography

Introduction: Pulmonary embolism (PE) is a common lethal disease that its clinical symptoms may be seen in many other diseases. Computed tomography pulmonary angiography (CTPA) is a valuable diagnostic modality for detection of PE. In addition, it can accurately detect the other diseases with clinical symptoms similar to PE. The aim of this study is to evaluate the frequency of PE and nonembolic disease with similar clinical symptoms including pulmonary, pleural, mediastinal, and cardiovascular diseases that have been detected by CTPA and to describe the importance of reporting these CT findings. Materials and Methods: In this cross‐sectional study, we evaluated the medical records of CTPA in 300 patients of suspected PE between March 2012 and February 2013 in Imam Reza Hospital and Ghaem Hospital in Mashhad University of Medical Sciences, Mashhad, Iran. Demographic information and the results of CTPA of these patients were re‐evaluated. One radiologist reviewed all of the CTPA and the results have been analyzed by SPSS‐16 software. Results: In this study, PE was detected in 18.7% of patients. Multiple incidental imaging findings were diagnosed as follow: pulmonary consolidation (33.2%), pleural effusion (48.7%), pulmonary nodules (10%), pulmonary masses (1.3%), pneumothorax (4.7%), mediastinal mass and lymphadenopathy (9.3%), aortic calcification (42%), coronary arteries calcification (27.3%), mitral valve calcification (2 %), cardiomegaly (30.7%), and the evidences of right ventricular dysfunction (6.7%). Conclusion: A group of disease can cause the clinical symptoms similar to that of PE. Among them, pulmonary consolidation and pleural effusion have much higher frequency than PE. In addition, CTPA can show pathologic findings in the patients that need follow‐up. It is important to detect and report these imaging findings because some of them may change the treatment and prognosis of patient who are suspected to have PE.

The Value of CTPA for Diagnosing Acute Pulmonary Thromboembolism and the Ensuing Right Ventricular Dysfunction

The value of computed tomography pulmonary angiography (CTPA) for the diagnosis of right ventricular dysfunction (RVD) subsequent to acute pulmonary embolism (PE). The ultrasonic cardiography (UCG) was used to assess RVD, one of the diagnostic criteria of PE caused hemodynamic collapse. Seventy six patients with confirmed PE were divided into massive (52 cases) and non-massive PE group (24 cases). The diagnostic criteria assessed for the imminent RVD were: (1) the ratio of axial diameters of the right and left ventricular chambers (RVd/LVd) exceeding 1, or (2) the right ventricular end-diastolic diameter measuring >30 mm. The CTPA diagnosed RVD was positive in 36 and negative in 40 cases. The RVD assessed by UCG was positive in 31 and negative in 45 cases. In comparison to UCG, the CTPA results UCG exhibited 96.77 % sensitivity 96.77 % and 86.67 specificity. The evaluated values both of these techniques were found in good agreement by the kappa value (κ) of 0.81, P < 0.001. In 52 cases of massive PE, CTPA determined RVD was positive in 34, and negative in 18 cases. In comparison, UCG diagnosed RVD was positive in 31 and negative in 21 cases. The sensitivity and specificity of CTPA results compared to those of UCG were 91.18 and 85.71 %, respectively. The estimates obtained were in good agreement as indicated by 0.88 κ value and P < 0.001. Twenty four cases of non-massive PE were RVD negative when assessed by CTPA, UCG however showed two cases positive in this group. Compared to UCG, the specificity of CTPA in evaluating RVD was 100 %. In the massive PE group, the average estimate of RVd/LVd ratio was significantly higher than 1 as analyzed by the non-parametric Mann-Whitney test (P < 0.001). The CTPA and UCG results showed a good correlation in massive PE cases. However, in non-massive PE group, results from two techniques were not correlated. The CTPA can accurately and reliably diagnose the PE and ensuing by estimating changes in the anatomical parameters of right ventricle. Hence, it can allow prompt diagnosis and an appropriate treatment leading to an improved prognosis.