Diagnosis Of Acute Pulmonary Thromboembolism Research Articles

Validation of a Recently Developed Fluoroscopic Video Analysis Workstation (Radwisp™) for the Reliable Diagnosis of Acute Pulmonary Thromboembolism.

Objective Radwisp™ is a fluoroscopic video analysis workstation recently developed to evaluate pulmonary circulation, thereby obviating the need for contrast medium or breath-holding. This study validated Radwisp as a diagnostic tool for acute pulmonary embolism (APE) and evaluated its potential utility in patients with symptoms of suspected APE. Methods The study included 10 patients (mean age, 69±16 years old) who were admitted to our hospital for suspected APE based on symptoms and physical examination findings between January 2020 and April 2021. Contrast-enhanced computed tomography (CT) and cineradiography, based on standard radiographs for the creation of a Radwisp image, were performed on the same day. Of the 10 cases of suspected APE, 7 were definitively diagnosed by CT with APE, and 3 were definitively diagnosed as not having APE. Fifty physicians (25 cardiologists and 25 residents) were blinded to patient information and CT images and asked to diagnose the presence of APE based solely on the Radwisp images. Results A total of 250 diagnoses were made by cardiologists and 250 by residents. Among the cardiologists, the sensitivity and specificity of the Radwisp-based analysis were 91% and 48%, respectively, and the positive and negative predictive values were 80% and 69%, respectively. Among the residents, the sensitivity and specificity were 88% and 35%, respectively, and the positive and negative predictive values were 76% and 55%, respectively. Conclusion This study showed an initial validation of Radwisp for diagnosing APE, revealing a high sensitivity but not yet achieving a high specificity. Further studies with a larger number of cases are needed to thoroughly evaluate the diagnostic performance.

Development and validation of a lung graph-based machine learning model to predict acute pulmonary thromboembolism on chest noncontrast computed tomography.

Computed tomography pulmonary angiography (CTPA) is a first-line noninvasive method to diagnose acute pulmonary thromboembolism (APE); however, whether chest noncontrast CT (NC-CT) could aid in the diagnosis of APE remains unknown. The aim of this study was to build and evaluate a holistic lung graph-based machine learning (HLG-ML) using NC-CT for the diagnosis of APE and to compare its performance with that of radiologists and the YEARS algorithm. This study enrolled 178 cases (77 males; age 63.9±16.7 years) who underwent NC-CT and CTPA in the same day from January 2019 to December 2020. Of these patients, 133 (75% of cases; 58 males; age 65.4±15.6 years) were placed into a training group and 45 (25% of cases; 19 males; age 59.6±19.2 years) into a testing group. The other 43 cases (18 males; age 62.8±20.0 years) were used to externally validate the model between January 2021 and March 2022. A HLG was developed with a pulmonary radiomics descriptor derived from NC-CT images. The approach extracted local radiomics features and encoded these local features into a radiomics descriptor as a characterization of global radiomics feature distribution. Subsequently, 8 ML models were trained and compared based on the radiomics descriptor. In the validation group, area under the curves (AUCs) of the HLG-ML model in the diagnosis of APE were compared with those of the 3 radiologists and the YEARS algorithm. Among the 8 ML models, gradient boosting decision tree demonstrated the best classification performance (AUC =0.772) on the training set. In the testing set, the AUC of gradient boosting decision trees was 0.857 [95% confidence intervals (CIs): 0.699-0.951]. In the validation set, the performance of gradient boosting decision tree (AUC =0.810; 95% CI: 0.669-0.952; Youden index =0.621) outperformed 3 radiologists (AUC =0.508, 95% CI: 0.335-0.681, Youden index =0.016; AUC =0.504, 95% CI: 0.354-0.654, Youden index =0.008; AUC =0.527, 95% CI: 0.363-0.691, Youden index =0.050) and the YEARS algorithm (AUC =0.618; 95% CI: 0.469-0.767; Youden index =0.237). Compared to all 3 radiologists and the YEARS algorithm, the proposed HLG-based gradient boosting decision tree model achieved a superior performance in the diagnosis of APE on the NC-CT and may thus serve as a valuable tool for physicians in the diagnosis of APE.

Investigation of the factors affecting the mortality of patients over 80 years of age diagnosed with acute pulmonary thromboembolism

Introduction: To investigate the factors affecting the 30-day mortality of patients over 80 years of age diagnosed with acute pulmonary thromboembolism. Materials and method: This descriptive, retrospective, and single-center study reviewed the medical records of patients over 80 years of age who were admitted to the hospital with a diagnosis of acute pulmonary thromboembolism between January 1, 2008, and April 30, 2023. The factors associated with mortality in patients who had died were examined. The recorded values of factors considered to be the determinants of 30-day mortality were also determined. Results: This study included 113 patients, with a mean age of 83.7 ± 2.7 years, and comprised of 68 (60.2%) females. During the one-month follow-up period, 30 patients (26.5%) died of acute pulmonary thromboembolism or related complications. No statistically significant difference in age and gender was observed between the exitus and non-exitus groups (p > 0.05). Moreover, no significant difference was observed between the two groups in terms of hypertension and diabetes (p > 0.05), whereas other comorbidities were statistically significantly higher in the exitus group (p < 0.05). In the linear regression analysis, heart failure (p < 0.001), D-dimer level (p = 0.019), partial arterial oxygen pressure (p < 0.001), systolic pulmonary artery pressure (p < 0.001), and recent history of major surgery (p = 0.021) were found to be factors that affected the mortality. Conclusion: The presence of comorbidities, poor hemodynamic findings, poor oxygenation, high pulmonary artery pressure, and high D-dimer levels may be mortality indicators in acute pulmonary thromboembolism patients over 80 years of age. Keywords: Pulmonary Embolism; Mortality; Ages.

Evaluation of Right Ventricular Function and Dyssynchrony in a Dog Model of Acute Pulmonary Embolism: Diagnostic Utility and Reversibility.

BackgroundThe diagnosis of acute pulmonary thromboembolism is challenging in dogs. Little has been reported on changes in echocardiographic indices in dogs with acute pulmonary thromboembolism. The objective of this study was to validate the relationship between echocardiographic indices and right heart catheterization variables in dogs with acute pulmonary embolism and to identify a useful echocardiographic index for diagnosing acute pulmonary embolism.Materials and MethodsSix healthy laboratory beagles were included in the study. Echocardiography and right heart catheterization were performed in a dog model of acute pulmonary embolism produced by microsphere injection. Echocardiographic indices, including the right ventricular (RV) Tei index, RV longitudinal strain, and the dyssynchrony index using speckle tracking echocardiography, transmitral flow, and eccentricity index, were measured.ResultsThe mean pulmonary arterial pressure increased (22.2 ± 1.2 mmHg) and the blood pressure decreased after microsphere injection. Although the mean pulmonary arterial pressure remained elevated, the blood pressure recovered 2 days after the microsphere injection. Most echocardiographic indices of RV function were significantly impaired following microsphere injection and recovered after 2 days. In contrast, the RV Tei index was significantly impaired after microsphere injection and the impairment persisted after 2 days. Multivariable analysis revealed that the RV Tei index was an independent echocardiographic predictor of pulmonary vascular resistance (β = 0.88, P < 0.001), and transmitral early diastolic wave was an independent predictor of the cardiac index (β = −0.86, P = 0.001).ConclusionsThe RV Tei index is a useful echocardiographic index for diagnosing acute pulmonary embolism. Ventricular interdependence may be an important factor causing low cardiac output in dogs with acute pulmonary embolism.

The diagnostic accuracy of prospective investigative study of acute pulmonary embolism diagnosis criteria for the detection of acute pulmonary thromboembolism in acutely ill patients.

The practical diagnostic performance of Prospective Investigative Study of Acute Pulmonary Embolism Diagnosis (PISAPED) criteria for the detection of acute pulmonary thromboembolism (APTE) in hospitalized patients is not yet well determined. This is the report of the initial results of our recently implemented protocol to employ PISAPED. One hundred and forty-seven pulmonary perfusion scans with 1–3 mCi 99mTc-MAA of patients of a single pulmonologist were included. Patients with suspicious perfusion defects underwent single-photon emission computed tomography. Interpretations were done by consensus of two nuclear medicine specialists. Comparisons were done with chest X-ray or chest computed tomography when available. The interpreters had access to the clinical records. The scans were reported based on the PISAPED criteria as negative or positive for APTE or indeterminate. Patients were followed up for 6.2 ± 5.3 months when the final diagnosis confirming or excluding APTE was achieved. Patients aged 55.9 (17.2) years; 78 (53.1%) of them were female and 64 (43.8%) had high Wells’ score. The scans were positive, negative, and indeterminate in 17 (11.6%), 126 (85.7%), and 4 (2.7%) patients, respectively. In 6 out of 147 patients, follow-up was not completed and the final diagnosis was not achieved. APTE was finally diagnosed in 21 (14.3%) patients; 12 (57.1%) of them had positive scans. APTE was excluded in 116 (78.9%) patients; 112 (96.5%) of them had negative scans. The accuracy of the test for the diagnosis of APTE was 87.9%. Lung metastasis was the most frequent reason among false-negative cases. The lung perfusion scan using PISAPED criteria could be used with good accuracy in inpatient settings.

Factors associated with residual pulmonary thromboembolism detected by computed tomography pulmonary angiography

BACKGROUND: Complete resolution of pulmonary vascular obstruction is not totally achieved in patients with acute pulmonary thromboembolism (PE). In this study, we tried to identify the factors associated with residual PE.MATERIALS AND METHODS: Patients with a diagnosis of acute PE from two centers were retrospectively analyzed. Residual PE was detected by computed tomography (CT) pulmonary angiography. Investigated parameters were unprovoked PE, clinical severity index (pulmonary embolism severity index score), D-dimer, troponin I, central pulmonary embolism, clot burden (Qanadli score), CT indexes of right ventricle (RV) overload (RV/left ventricle and pulmonary artery/aorta), massive PE, coexisting deep venous thrombosis signs and symptoms, and follow-up CT time.RESULTS: On univariate analysis, follow-up CT time and clot burden at the time of diagnosis were significantly associated with residual PE (P = 0.02 and P = 0.002, respectively). Initial D-dimer levels were higher in patients with residual PE although statistical significance was not reached (P = 0.08). On multivariate analysis, clot burden and follow-up CT time remained significant (hazard ratio [95% confidence interval] of 4.31 [1.31–14.12] and 2.47 [0.92–6.62], respectively).CONCLUSION: Our results suggest that higher clot burden may be an independent predictor for residual PE along with the timing of follow-up CT.

The Role of Intrinsicoid Deflection Time in Precordial Leads Facing Right Ventricle and aVR for Diagnosis of Acute Pulmonary Thromboembolism and Determination Its Severity

The Role of Intrinsicoid Deflection Time in Precordial Leads Facing Right Ventricle and aVR for Diagnosis of Acute Pulmonary Thromboembolism and Determination Its Severity

Clinical application of the Innovance D-dimer assay in the diagnosis of acute pulmonary thromboembolism.

Patients with acute pulmonary thromboembolism (APTE) have a high short-term mortality rate. The current study aimed to investigate the use of D-dimer in the diagnosis of APTE in suspected APTE patients. All suspected APTE patients were classified into diagnosis or control groups according to the results of a computed tomography pulmonary angiogram. Mann-Whitney U and Kruskal-Wallis H tests were used to evaluate the association between D-dimer values and APTE. Area under the curve (AUC) values and the Youden Index were used to determine D-dimer cut-off levels for the prediction of APTE. The data of 112 suspected APTE patients (54.8% women; mean age, 70.5 years) were analyzed prospectively. There were no significant differences in age (74.5 vs. 73.5 years, P=0.538) or gender distribution (female ratio 56.5 vs. 53.0%, P=0.847) between the diagnosis and control groups. The incidence of symptoms including dyspnea (67.4 vs. 33.3%; P<0.01), chest distress (47.8 vs. 25.8%; P<0.05) and elevated D-dimer (8.49 vs. 0.97 mg/l; P<0.001) were significantly higher in patients with APTE compared with the control group. D-dimer values >3.32 mg/l fibrinogen equivalent units (FEU) were indicative of APTE and the Youden Index was 0.69. The maximum AUC was 0.87 (95% CI: 0.79-0.92), the sensitivity and specificity were 89.13 and 80.30%, respectively, the positive and negative likelihood ratios were 4.53 and 0.14, respectively, and the positive and negative predictive values were 75.90 and 91.40%, respectively. A D-dimer value <0.60 mg/l FEU was the optimal threshold for excluding APTE diagnosis, with a sensitivity of 100.0% and a specificity of 28.79%. The positive and negative likelihood ratios were 1.40 and 0.00, respectively, and the positive and negative predictive values were 49.50 and 100.00%, respectively. Thus, D-dimer levels, combined with clinical assessment, yield high sensitivity and specificity in diagnosing APTE.

Acute pulmonary thromboembolism: Epidemiology, predictors, and long-term outcome – A single center experience

IntroductionAcute pulmonary thromboembolism (PTE) is a life-threatening disease. Mortality in PTE still remains very high in spite of progress in diagnostic tools. Mortality rate is about 30% in patients with unrecognized acute PTE. MethodsIt is a single center observational study of 31 consecutive patients who were hospitalized in the Department of Cardiology at MS Ramaiah Memorial hospital between January 1, 2010 and June 2015. All the patients confirmed with diagnosis of acute PTE by CT scan (either HRCT or CTPA) were included in the study. Following relevant investigations chosen patients were risk stratified as per standard guidelines into massive, sub massive or low risk and treated accordingly. The included patients were followed up for a period of 1 year with 2D-echocardiogram and other relevant investigations for comparison to assess improvement. Mortality due to either acute PTE or other causes was noted in the study. ResultsOf the 31 patients enrolled in our study, 71% (n=22) of the patients belonged to the age range 20–50 years with those in the age group 31–40 years comprising 39% (n=12) of the total. Elderly people over 65 years of age comprised only 19% (n=6) of the total number of patients. Dyslipidemia, prolonged immobilization, deep vein thrombosis, post-operative state, malignancy and post-partum period were the commonly reported risk factors. We thrombolysed a total of 18 (58%) patients with massive and submassive PTE, of which 12 (39%) received tenecteplase and 6 patients received streptokinase (19%). Three (9%) patients required repeat thrombolysis with streptokinase due to failed thrombolytic therapy with tenecteplase. ConclusionsOur study reported higher incidence of acute PTE in the middle age group population. Prevalence of dyslipidemia was high in this cohort of patients studied although the exact association of it in APE could not be determined. Thrombolytic therapy can be considered for patients with both massive and submassive pulmonary thromboembolism. Repeat thrombolysis can be considered in case one thrombolytic agent failed to give the desirable results.

Usefulness of Echocardiography on Early Diagnosis of Acute Pulmonary Thromboembolism

Background: Prevalence of multislice CT facilitate the diagnosis of acute pulmonary thromboembolism, but it is still difficult to suspect this disease at the initial visit. The purpose of this study is to determine echocardiographic predictive factors for the early detection of acute pulmonary thromboembolism. Methods: 16 patients with suspected acute pulmonary thromboembolism underwent contrast-enhanced computed tomography were enrolled. Patients were devided according to the presence (PTE, n = 8) or absence (nPTE, n = 8) of pulmonary thromboembolism. We compared D-dimmer, LVEF by Simpsom method, TASPE, RVAd, RVFAC, Tr-PG, Pr-PG, acceleration time of PA (ActPA), and deceleration time of PA (DctPA). Results: D-dimmer (7.8±5.7 vs. 4.5 ± 4.4 µg/mL), LVEF (52.2 ± 15.1 vs. 58.0 ± 10.7%), TASPE (14.9 ± 3.1 vs. 18.8 ± 2.9 mm), RVAd (20.3 ± 5.6 vs. 19.0 ± 2.3 mm2), Tr-PG (33.4 ± 11.7 vs. 30.3 ± 12.7 mmHg), and Pr-PG (6.6 ± 2.6 vs. 6.2 ± 2.3 mmHg) did not differ between the two groups. RVFAC was significantly lower in PTE than nPTE (37.1 ± 8.8 vs. 47.6 ± 8.0, P = .03), ActPA was shorter in PTE than nPTE (75.6 ± 25.3 vs. 117.6 ± 32.5%, P = .001), DctPA was longer in PTE than nPTE (238.0 ± 56.6 vs. 160.0 ± 33.4 msec., P = .02). Conclusion: ActPA and DctPA are sensitive and noninvasive marker even for the patients whose Tr-PG and Pr-PG are normal.

Valor pronóstico de la tomografía computarizada en la tromboembolia pulmonar aguda

In addition to being the standard reference for the diagnosis of acute pulmonary thromboembolism, CT angiography of the pulmonary arteries can also provide valuable information about the patient's prognosis. Although which imaging findings are useful for prognosis remains controversial, signs of right ventricular dysfunction on CT are now included in clinical algorithms for the management of pulmonary thromboembolism. However, the optimal method for obtaining these measurements while maintaining a balance between the ease of use necessary to include their evaluation in our daily activity and the loss of precision in its predictive capacity remains to be determined. Moreover, other variables associated with pulmonary thromboembolism that often go unobserved can complement the prognostic information we can offer to clinicians. This review aims to clarify some of the more controversial aspects related to the prognostic value of CT in patients with pulmonary embolisms according to the available evidence. Knowing which variables are becoming more important in the prognosis, how to detect them, and why it is important to include them in our reports will help improve the management of patients with pulmonary embolism.

ACUTE PULMONARY THROMBOEMBOLISM DUE TO DEPRESSION: A UNUSUAL CAUSE OF A FREQUENT DISEASE

BACKGROUND: Acute pulmonary thromboembolism (APTE) is common and potentially life-threatening cardiovascular emergency. The fatality rate in acute cases ranges from 7-11%. There are many predisposing risk factors for APTE. Depressed, inactive patients would appear to be at significant risk for pulmonary embolism, given their lack of activity and putative platelet pathology. METHODS AND RESULTS: We report a clinical case of a 41 years old patient flowed for depression 4 months ago who reported that he spent almost all of his time in bed, sleeping with limited physical activity, that presenting at the emergency for acute onset of fatigue, shortness of breath and dyspnoea a few hours before admission, the anamnesis revealed no classical factors of veinous thromboembolism, the clinical examination fount a tachycardia, tachypnea, without clinical evidence of heart failure, the D-Dimer level was elevated, and the thoracic CT angiogram revealed intraluminal thrombi in lobar and segmental branches of the pulmonary arteries causing incomplete luminal obstruction. Diagnosis of APTE was confirmed, further etiological investigations ruled out other etiology of the venous thromboembolism. the patient was treated by anticoagulant, and antidepressant therapy with good clinical improvement. CONCLUSION: Severe major depression associated with psychomotor retardation and immobility can be a risk factor for pulmonary embolism. We must remember to search a depression in patients with pulmonary embolism and may be use a prophylaxis for this kind of patients.

CAROTID PLAQUE HEIGHT HELPS ADDRESS THE CHALLENGE OF DIAGNOSING HEART DISEASE IN WOMEN

BACKGROUND: Acute pulmonary thromboembolism (APTE) is common and potentially life-threatening cardiovascular emergency. The fatality rate in acute cases ranges from 7-11%. There are many predisposing risk factors for APTE. Depressed, inactive patients would appear to be at significant risk for pulmonary embolism, given their lack of activity and putative platelet pathology. METHODS AND RESULTS: We report a clinical case of a 41 years old patient flowed for depression 4 months ago who reported that he spent almost all of his time in bed, sleeping with limited physical activity, that presenting at the emergency for acute onset of fatigue, shortness of breath and dyspnoea a few hours before admission, the anamnesis revealed no classical factors of veinous thromboembolism, the clinical examination fount a tachycardia, tachypnea, without clinical evidence of heart failure, the D-Dimer level was elevated, and the thoracic CT angiogram revealed intraluminal thrombi in lobar and segmental branches of the pulmonary arteries causing incomplete luminal obstruction. Diagnosis of APTE was confirmed, further etiological investigations ruled out other etiology of the venous thromboembolism. the patient was treated by anticoagulant, and antidepressant therapy with good clinical improvement. CONCLUSION: Severe major depression associated with psychomotor retardation and immobility can be a risk factor for pulmonary embolism. We must remember to search a depression in patients with pulmonary embolism and may be use a prophylaxis for this kind of patients.

THERE IS NO CLINICAL JUSTIFICATION FOR CAROTID SCREENING IN MALES OVER 70 YEARS OR FEMALES OVER 75 YEARS

BACKGROUND: Acute pulmonary thromboembolism (APTE) is common and potentially life-threatening cardiovascular emergency. The fatality rate in acute cases ranges from 7-11%. There are many predisposing risk factors for APTE. Depressed, inactive patients would appear to be at significant risk for pulmonary embolism, given their lack of activity and putative platelet pathology. METHODS AND RESULTS: We report a clinical case of a 41 years old patient flowed for depression 4 months ago who reported that he spent almost all of his time in bed, sleeping with limited physical activity, that presenting at the emergency for acute onset of fatigue, shortness of breath and dyspnoea a few hours before admission, the anamnesis revealed no classical factors of veinous thromboembolism, the clinical examination fount a tachycardia, tachypnea, without clinical evidence of heart failure, the D-Dimer level was elevated, and the thoracic CT angiogram revealed intraluminal thrombi in lobar and segmental branches of the pulmonary arteries causing incomplete luminal obstruction. Diagnosis of APTE was confirmed, further etiological investigations ruled out other etiology of the venous thromboembolism. the patient was treated by anticoagulant, and antidepressant therapy with good clinical improvement. CONCLUSION: Severe major depression associated with psychomotor retardation and immobility can be a risk factor for pulmonary embolism. We must remember to search a depression in patients with pulmonary embolism and may be use a prophylaxis for this kind of patients.

Management of Cardiac Arrest Caused by Acute Massive Pulmonary Thromboembolism

Cardiac arrest caused by acute pulmonary embolism is associated with high patient mortality. We reviewed patients who had cardiac arrest caused by acute pulmonary embolism. Between January 2001 and September 2013, we identified 20 patients at our institution with a confirmative diagnosis of acute pulmonary thromboembolism and cardiac arrest. Percutaneous cardiopulmonary support (PCPS) and surgical embolectomy are the standard course of care for patients with shock or cardiac arrest caused by pulmonary thromboembolism at our institution. Patients were divided into two groups (PCPS group and non-PCPS group). Percutaneous cardiopulmonary support was used in 60% of patients. Surgical embolectomy was performed for 85% of patients. Overall in-hospital and surgical mortalities were 35% and 29%, respectively. On the basis of the multivariate analysis, both cardiopulmonary resuscitation more than 15 minutes and absence of PCPS were significant risk factors affecting survival (p = 0.001 and 0.049, respectively). When the duration of cardiac arrest is short, surgical embolectomy is a viable option after cardiac arrest caused by pulmonary thromboembolism. Percutaneous cardiopulmonary support may be a useful tool for both stabilizing the patient and providing a bridge when deciding on further management options.

Effect of Delay in Hospital Presentation on Clinical and Imaging Findings in Acute Pulmonary Thromboembolism

BackgroundThere is limited information on the extent and clinical importance of the delay in hospital presentation of acute pulmonary thromboembolism (PTE). ObjectiveThe aim of this study was to investigate the delay in hospital presentation of PTE and its association with clinical and imaging findings in PTE. MethodsThis prospective study was conducted on patients admitted to our hospital with a diagnosis of acute PTE between September 2007 and September 2011. Relationships between delay in hospital presentation and clinical findings, risk factors, imaging findings, and in-hospital mortality were analyzed. ResultsOf the 195 patients enrolled, 84 (43.1%) patients presented 3 days after the onset of symptoms. Patients with chest pain, history of immobility for more than 3 days, recent surgery, and estrogen use had significantly less delayed presentation. Right ventricular dysfunction was significantly more frequent in patients with delayed presentation (odds ratio [OR] = 2.38; 95% confidence interval [CI] 1.27−4.44; p = 0.006); however, no relationship was found between delay in presentation and pulmonary computed tomographic angiography or color Doppler sonography findings. Patients with delayed presentation were at higher risk of in-hospital mortality (OR = 4.32; 95% CI 1.12−16.49; p = 0.021). ConclusionsOur study showed that a significant portion of patients with acute PTE had delayed presentation. Also, patients with delayed presentation had worse echocardiographic findings and higher in-hospital mortality.

Mounier-Kuhn syndrome masquerading pulmonary thromboembolism in an elderly male

Mounier-Kuhn syndrome, also referred to as tracheobronchomegaly, is a rare idiopathic clinical and radiologic disorder characterized by significant tracheobronchial dilation. It results in recurrent lower respiratory tract infections and bronchiectasis. In severe cases, patients may present with acute respiratory distress requiring hospital admission and ventilatory support. Clinical examination and chest radiography may be misleading in these patients as tracheobronchomegaly is easily overlooked on radiographs. We present an interesting report of our patient who presented with acute shortness of breath. A diagnosis of acute pulmonary thromboembolism was suggested by initial evaluation. Computed tomography pulmonary angiography was negative for thromboembolism; however, it revealed diagnosis of this rare disorder.

Different Perfusion Pattern Between Acute and Chronic Pulmonary Thromboembolism: Evaluation With Two-Phase Dual-Energy Perfusion CT

The purpose of this study was to evaluate whether two-phase dual-energy CT can differentiate between lung perfusion patterns of patients with chronic pulmonary thromboembolism (PTE) and those of patients with acute PTE. A total of 114 patients clinically suspected to have PTE were prospectively enrolled. All patients underwent dual-energy CT at pulmonary artery (PA) and delayed phases. Of 68 patients diagnosed with PTE on CT, 42 were finally included. Iodine-related attenuation values (IRAs) were measured in PA and delayed phases for each lung segment, and IRA change ratios were calculated using the formula 100% × [(IRA of delayed phase) - (IRA of PA phase)]/(IRA of PA phase). Among the 42 patients (19 men and 23 women; mean age, 60.3 ± 13.2 years; range, 28-82 years), 24 had a diagnosis of acute PTE and 18 of chronic PTE. Those segments with both perfusion and filling defects (n = 143) in patients with acute PTE showed no significant changes of mean IRA between PA and delayed phases, whereas the segments from patients with chronic PTE (n = 94) showed significantly increased IRA on delayed phase as compared with PA phase. The mean IRA change ratios in acute and chronic PTE were -3.14% and 191.9%, respectively (p < 0.0001). Chronic PTE segments were significantly more enhanced on the delayed phase of two-phase dual-energy CT images than were acute PTE segments, possibly resulting from more extensive systemic collateral formation in chronic PTE. Two-phase dual-energy CT can be used to differentiate distinct regional perfusion patterns between acute and chronic PTE.

Imaging of acute pulmonary embolism

Acute pulmonary thromboembolism (PE) is a cardiovascular emergency associated with significant morbidity and a 5-35 % mortality for untreated pulmonary embolism. If promptly diagnosed and treated, the mortality rate can be significantly reduced. Diagnosis of acute PE continues to be a clinical challenge, with diagnostic imaging playing an important role. This review discusses the clinical challenges of diagnosing acute PE, presents an evidence-based review of the current tests and ever-evolving imaging technology, and highlights special considerations related to radiation dose, contrast media use, and pregnant patients.

Circulating cell-free DNA levels in plasma increase with severity in experimental acute pulmonary thromboembolism

Background The diagnosis of acute pulmonary thromboembolism (APT) and its severity is challenging. No previous study has examined whether there is a linear relation between plasma DNA concentrations and the severity of APT. We examined this hypothesis in anesthetized dogs. We also examined the changes in plasma DNA concentrations in microspheres lung embolization and whether the therapy of APT with nitrite could modify APT-induced changes in plasma DNA concentrations. In vitro DNA release from blood clots was also studied. Methods APT was induced with autologous blood clots (saline, 1, 3, or 5 ml/kg) injected into the right atrium. A group of dogs received 300 µm microspheres into the inferior vena cava to produce similar pulmonary hypertension. Another group of dogs received 6.75 µmol/kg nitrite after APT with blood clots of 5 ml/kg. Hemodynamic evaluations were carried out for 120 min. DNA was extracted from plasma samples using QIAamp DNA Blood Mini Kit and quantified using Quant-iT ™ PicoGreen ® dsDNA detection kit at baseline and 120 min after APT. Results APT produced dose-dependent increases in plasma DNA concentrations, which correlated positively with pulmonary vascular resistance ( P = 0.002, r = 0.897) and with mean pulmonary arterial pressure ( P = 0.006, r = 0.856). Conversely, lung embolization with microspheres produced no significant changes in plasma DNA concentrations. While nitrite attenuated APT-induced pulmonary hypertension, it produced no changes in plasma DNA concentrations. Blood clots released dose-dependent amounts of DNA in vitro. Conclusions Cell-free DNA concentrations increase in proportion to the severity of APT, probably as a result of increasing amounts of thrombi obstructing the pulmonary vessels.