Diagnostic value of D-dimer in patients with suspected pulmonary embolism: results from a multicentre outcome study

Validation of American Society of Echocardiography Guideline-Recommended Parameters of Right Ventricular Dysfunction Using Artificial Intelligence Compared With Cardiac Magnetic Resonance Imaging

BACKGROUND

Right ventricular (RV) function is important in the evaluation of cardiac function, but its assessment using standard transthoracic echocardiography (TTE) remains challenging. Cardiac magnetic resonance imaging (CMR) is considered the gold standard. The American Society of Echocardiography recommends surrogate measures of RV function and RV ejection fraction (RVEF) by TTE, including fractional area change (FAC), free wall strain (FWS), and tricuspid annular planar systolic excursion (TAPSE), but they require technical expertise in acquisition and quantification.

METHODS

The aim of this study was to evaluate the sensitivity, specificity, and positive and negative predictive values of FAC, FWS, and TAPSE derived using a rapid, novel artificial intelligence (AI) software (LVivoRV) from a single-plane transthoracic echocardiographic apical four-chamber, RV-focused view without ultrasound-enhancing agents for detecting abnormal RV function compared with CMR-derived RVEF. RV dysfunction was defined as RVEF < 50% and RVEF < 40% on CMR.

RESULTS

TTE and CMR were performed within a median of 10 days (interquartile range, 2-32 days) of each other in 225 consecutive patients without interval procedural or pharmacologic intervention. The sensitivity and negative predictive value to detect CMR-defined RV dysfunction when all three AI-derived parameters (FAC, FWS, and TAPSE) were abnormal were 91% and 96%, while those of expert physician reads were 91% and 97%. Specificity and positive predictive value were lower (50% and 32%) compared with expert physician-read echocardiograms (82% and 56%).

CONCLUSIONS

AI-derived measurements of FAC, FWS, and TAPSE had excellent sensitivity and negative predictive value for ruling out significant RV dysfunction (CMR RVEF < 40%), comparable with that of expert physician readers, but lower specificity. Thus AI, using American Society of Echocardiography guidelines, may serve as a useful screening tool for rapid bedside assessment to exclude significant RV dysfunction.

An efficient and fast multi-band focused bioimpedance solution with EIT-based reconstruction for pulmonary embolism assessment: a simulation study from massive to segmental blockage

OBJECTIVE

Pulmonary embolism (PE) is an acute condition that blocks the perfusion to the lungs and is a common complication of Covid-19. However, PE is often not diagnosed in time, especially in the pandemic time due to complicated diagnosis protocol. In this study, a non-invasive, fast and efficient bioimpedance method with the EIT-based reconstruction approach is proposed to assess the lung perfusion reliably.

APPROACH

Some proposals are presented to improve the sensitivity and accuracy for the bioimpedance method: (1) a new electrode configuration and focused pattern to help study deep changes caused by PE within each lung field separately, (2) a measurement strategy to compensate the effect of different boundary shapes and varied respiratory conditions on the perfusion signals and (3) an estimator to predict the lung perfusion capacity, from which the severity of PE can be assessed. The proposals were tested on the first-time simulation of PE events at different locations and degrees from segmental blockages to massive blockages. Different object boundary shapes and varied respiratory conditions were included in the simulation to represent for different populations in real measurements.

RESULTS

The correlation between the estimator and the perfusion was very promising (R = 0.91, errors < 6%). The measurement strategy with the proposed configuration and pattern has helped stabilize the estimator to non-perfusion factors such as the boundary shapes and varied respiration conditions (3-5% errors).

SIGNIFICANCE

This promising preliminary result has demonstrated the proposed bioimpedance method's capability and feasibility, and might start a new direction for this application.

Research progress on biomarkers of pulmonary embolism

OBJECTIVES

To present a review on the traditional and new biomarkers of pulmonary embolism (PE).

DATA SOURCE

A systematic search has been carried out using keywords as PE, biomarker, diagnosis and risk stratification.

RESULTS

The results of this work have been structured into three parts: first, conventional biomarkers for vascular, cardiac and inflammation, including static markers and dynamic markers for measuring the time course; next, a review of new biomarkers in recent years, such as RNAs and markers obtained through proteomics and mass spectrometry; finally, use of new detection methods to directly detect the activity of existing markers, such as the determination of coagulation factor II and plasmin activities based on the proteolytic activation of an engineered zymogen.

CONCLUSIONS

This work summarized the characteristics of current traditional biomarkers for clinical diagnosis and risk stratification of PE, as well as a series of newly discovered biomarkers obtained through various clinical experimental methods.

Systematic review and meta-analysis of test accuracy for the diagnosis of suspected pulmonary embolism

Pulmonary embolism (PE) is a common, potentially life-threatening yet treatable condition. Prompt diagnosis and expeditious therapeutic intervention is of paramount importance for optimal patient management. Our objective was to systematically review the accuracy of D-dimer assay, compression ultrasonography (CUS), computed tomography pulmonary angiography (CTPA), and ventilation-perfusion (V/Q) scanning for the diagnosis of suspected first and recurrent PE. We searched Cochrane Central, MEDLINE, and EMBASE for eligible studies, reference lists of relevant reviews, registered trials, and relevant conference proceedings. 2 investigators screened and abstracted data. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 and certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework. We pooled estimates of sensitivity and specificity. The review included 61 studies. The pooled estimates for D-dimer sensitivity and specificity were 0.97 (95% confidence interval [CI], 0.96-0.98) and 0.41 (95% CI, 0.36-0.46) respectively, whereas CTPA sensitivity and specificity were 0.94 (95% CI, 0.89-0.97) and 0.98 (95% CI, 0.97-0.99), respectively, and CUS sensitivity and specificity were 0.49 (95% CI, 0.31-0.66) and 0.96 (95% CI, 0.95-0.98), respectively. Three variations of pooled estimates for sensitivity and specificity of V/Q scan were carried out, based on interpretation of test results. D-dimer had the highest sensitivity when compared with imaging. CTPA and V/Q scans (high probability scan as a positive and low/non-diagnostic/normal scan as negative) both had the highest specificity. This systematic review was registered on PROSPERO as CRD42018084669.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: diagnosis of venous thromboembolism

BACKGROUND

Modern diagnostic strategies for venous thromboembolism (VTE) incorporate pretest probability (PTP; prevalence) assessment. The ability of diagnostic tests to correctly identify or exclude VTE is influenced by VTE prevalence and test accuracy characteristics.

OBJECTIVE

These evidence-based guidelines are intended to support patients, clinicians, and health care professionals in VTE diagnosis. Diagnostic strategies were evaluated for pulmonary embolism (PE), deep vein thrombosis (DVT) of the lower and upper extremity, and recurrent VTE.

METHODS

The American Society of Hematology (ASH) formed a multidisciplinary panel including patient representatives. The McMaster University GRADE Centre completed systematic reviews up to 1 October 2017. The panel prioritized questions and outcomes and used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations. Test accuracy estimates and VTE population prevalence were used to model expected outcomes in diagnostic pathways. Where modeling was not feasible, management and accuracy studies were used to formulate recommendations.

RESULTS

Ten recommendations are presented, by PTP for patients with suspected PE and lower extremity DVT, and for recurrent VTE and upper extremity DVT.

CONCLUSIONS

For patients at low (unlikely) VTE risk, using D-dimer as the initial test reduces the need for diagnostic imaging. For patients at high (likely) VTE risk, imaging is warranted. For PE diagnosis, ventilation-perfusion scanning and computed tomography pulmonary angiography are the most validated tests, whereas lower or upper extremity DVT diagnosis uses ultrasonography. Research is needed on new diagnostic modalities and to validate clinical decision rules for patients with suspected recurrent VTE.

D-dimer value in the diagnosis of pulmonary embolism-may it exclude only?

Background

Pulmonary embolism (PE) is the third most common cause of death for cardiovascular diseases in Europe. Quick PE diagnosis is therefore crucial for prognosis improvement. It is critical to have suitable screening tests both to exclude PE as well to select patient with highest likelihood of PE occurrence. Currently D-dimer test is accepted as important tool useful to exclude PE in low risk patients. Our goal was to assess the D-dimer test positive prognostic value.

Methods

A retrospective study based on medical record analysis of consecutively admitted patients to 9 wards of The University Clinical Center in Katowice who were hospitalized during four consecutive years was performed. Three hundred and seventy patients met the inclusion criteria for the study, which involved the D-dimer tests and computed tomographic pulmonary angiography (CTPA) performed during hospitalization. Assessed patients were divided into two groups: PE confirmed and PE excluded by CTPA.

Results

We have found that patients with D-dimer levels higher than 2,152 ng/mL had significantly increased risk of PE [area under curve (AUC) of 0.69; 95% CI, 0.64-0.75; P<0.05]. Positive predictive value (PPV) reached the level of 53%, whereas negative predictive value (NPV) reached 82%. We also found that patients with the history of neoplasm and at >65 years of age had D-dimer cut-off point moved to the level of 2,652 ng/mL (AUC of 0.67; 95% CI, 0.52-0.81; P<0.05).

Conclusions

Whereas the NPV of the D-dimer test is generally accepted our results suggest that, in selected cases, an increased plasmatic D-dimer levels may have PPV in PE diagnosis. Patients with the history of neoplasm have higher cut-off D-dimer points above which we should consider increased PE likelihood. CTPA should be considered even for patients with low probability of PE when D-dimer values exceed four times the normal level.

The Role of Pulmonary Veins in Cancer Progression from a Computed Tomography Viewpoint

Background. We studied the role of pulmonary veins in cancer progression using computed tomography (CT) scans. Methods. We obtained data from 260 patients with pulmonary vein obstruction syndrome (PVOS). We used CT scans to investigate pulmonary lesions in relation to pulmonary veins. We divided the lesions into central and peripheral lesions by their anatomical location: in the lung parenchymal tissue or pulmonary vein; in the superior or inferior pulmonary vein; and by unilateral or bilateral presence in the lungs. Results. Of the 260 PVOS patients, 226 (87%) had central lesions, 231 (89%) had peripheral lesions, and 190 (75%) had mixed central and peripheral lesions. Among the 226 central lesions, 93% had lesions within the superior pulmonary vein, either bilaterally or unilaterally. Among the 231 peripheral lesions, 65% involved bilateral lungs, 70% involved lesions within the inferior pulmonary veins, and 23% had obvious metastatic extensions into the left atrium. All patients exhibited nodules within their pulmonary veins. The predeath status included respiratory failure (40%) and loss of consciousness (60%). Conclusion. CT scans play an important role in following tumor progression within pulmonary veins. Besides respiratory distress, PVOS cancer cells entering centrally can result in cardiac and cerebral events and loss of consciousness or can metastasize peripherally from the pulmonary veins to the lungs.

D-dimer test for excluding the diagnosis of pulmonary embolism

BACKGROUND

Pulmonary embolism (PE) can occur when a thrombus (blood clot) travels through the veins and lodges in the arteries of the lungs, producing an obstruction. People who are thought to be at risk include those with cancer, people who have had a recent surgical procedure or have experienced long periods of immobilisation and women who are pregnant. The clinical presentation can vary, but unexplained respiratory symptoms such as difficulty breathing, chest pain and an increased respiratory rate are common.D-dimers are fragments of protein released into the circulation when a blood clot breaks down as a result of normal body processes or with use of prescribed fibrinolytic medication. The D-dimer test is a laboratory assay currently used to rule out the presence of high D-dimer plasma levels and, by association, venous thromboembolism (VTE). D-dimer tests are rapid, simple and inexpensive and can prevent the high costs associated with expensive diagnostic tests.

OBJECTIVES

To investigate the ability of the D-dimer test to rule out a diagnosis of acute PE in patients treated in hospital outpatient and accident and emergency (A&E) settings who have had a pre-test probability (PTP) of PE determined according to a clinical prediction rule (CPR), by estimating the accuracy of the test according to estimates of sensitivity and specificity. The review focuses on those patients who are not already established on anticoagulation at the time of study recruitment.

SEARCH METHODS

We searched 13 databases from conception until December 2013. We cross-checked the reference lists of relevant studies.

SELECTION CRITERIA

Two review authors independently applied exclusion criteria to full papers and resolved disagreements by discussion.We included cross-sectional studies of D-dimer in which ventilation/perfusion (V/Q) scintigraphy, computerised tomography pulmonary angiography (CTPA), selective pulmonary angiography and magnetic resonance pulmonary angiography (MRPA) were used as the reference standard.•

PARTICIPANTS

Adults who were managed in hospital outpatient and A&E settings and were suspected of acute PE were eligible for inclusion in the review if they had received a pre-test probability score based on a CPR.•

INDEX TESTS

quantitative, semi quantitative and qualitative D-dimer tests.• Target condition: acute symptomatic PE.• Reference standards: We included studies that used pulmonary angiography, V/Q scintigraphy, CTPA and MRPA as reference standard tests.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed quality using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). We resolved disagreements by discussion. Review authors extracted patient-level data when available to populate 2 × 2 contingency tables (true-positives (TPs), true-negatives (TNs), false-positives (FPs) and false-negatives (FNs)).

MAIN RESULTS

We included four studies in the review (n = 1585 patients). None of the studies were at high risk of bias in any of the QUADAS-2 domains, but some uncertainty surrounded the validity of studies in some domains for which the risk of bias was uncertain. D-dimer assays demonstrated high sensitivity in all four studies, but with high levels of false-positive results, especially among those over the age of 65 years. Estimates of sensitivity ranged from 80% to 100%, and estimates of specificity from 23% to 63%.

AUTHORS' CONCLUSIONS

A negative D-dimer test is valuable in ruling out PE in patients who present to the A&E setting with a low PTP. Evidence from one study suggests that this test may have less utility in older populations, but no empirical evidence was available to support an increase in the diagnostic threshold of interpretation of D-dimer results for those over the age of 65 years.

Values of the Wells and revised Geneva scores combined with D-dimer in diagnosing elderly pulmonary embolism patients

BACKGROUND

Pulmonary embolism (PE) can be difficult to diagnose in elderly patients because of the coexistent diseases and the combination of drugs that they have taken. We aimed to compare the clinical diagnostic values of the Wells score, the revised Geneva score and each of them combined with D-dimer for suspected PE in elderly patients.

METHODS

Three hundred and thirty-six patients who were admitted for suspected PE were enrolled retrospectively and divided into two groups based on age (≥65 or <65 years old). The Wells and revised Geneva scores were applied to evaluate the clinical probability of PE, and the positive predictive values of both scores were calculated using computed tomography pulmonary arteriography as a gold standard; overall accuracy was evaluated by the area under the curve (AUC) of receiver operator characteristic curve; the negative predictive values of D-dimer, the Wells score combined with D-dimer, and the revised Geneva score combined with D-dimer were calculated.

RESULTS

Ninety-six cases (28.6%) were definitely diagnosed as PE among 336 cases, among them 56 cases (58.3%) were ≥65 years old. The positive predictive values of Wells and revised Geneva scores were 65.8% and 32.4%, respectively (P < 0.05) in the elderly patients; the AUC for the Wells score and the revised Geneva score in elderly was 0.682 (95% confidence interval [CI]: 0.612-0.746) and 0.655 (95% CI: 0.584-0.722), respectively (P = 0.389). The negative predictive values of D-dimer, the Wells score combined with D-dimer, and the revised Geneva score combined with D-dimer were 93.7%, 100%, and 100% in the elderly, respectively.

CONCLUSIONS

The diagnostic value of the Wells score was higher than the revised Geneva score for the elderly cases with suspected PE. The combination of either the Wells score or the revised Geneva score with a normal D-dimer concentration is a safe strategy to rule out PE.

Pulmonary Venous Obstruction in Cancer Patients

Background. We study the clinical significance and management of pulmonary venous obstruction in cancer patients. Methods. We conducted a prospective cohort study to characterize the syndrome that we term “pulmonary vein obstruction syndrome” (PVOS) between January 2005 and March 2014. The criteria for inclusion were (1) episodes of shortness of breath; (2) chest X-ray showing abnormal pulmonary hilum shadow with or without presence of pulmonary edema and/or pleural effusion; (3) CT scan demonstrating pulmonary vein thrombosis/tumor with or without tumor around the vein. Results. Two hundred and twenty-two patients developed PVOS. Shortness of breath was the main symptom, which was aggravated by chemotherapy in 28 (13%), and medical/surgical procedures in 21 (9%) and showed diurnal change in intensity in 32 (14%). Chest X-rays all revealed abnormal pulmonary hilum shadows and presence of pulmonary edema in 194 (87%) and pleural effusion in 192 (86%). CT scans all showed pulmonary vein thrombosis/tumor (100%) and surrounding the pulmonary veins by tumor lesions in 140 patients (63%). PVOS was treated with low molecular weight heparin in combination with dexamethasone, and 66% of patients got clinical/image improvement. Conclusion. Physicians should be alert to PVOS when shortness of breath occurs and chest X-ray reveals abnormal pulmonary hilum shadows.

The influence of education on appropriateness rates for CT pulmonary angiography in emergency department patients

RATIONALE AND OBJECTIVES

To evaluate appropriate utilization rates for computed tomography (CT) pulmonary angiography (CTPA) in a tertiary center emergency department (ED), before and after a health care provider educational intervention.

MATERIALS AND METHODS

Institutional Review Board-approved retrospective study. Records for 100 consecutive CTPA studies ordered by the ED were retrieved from a radiology database. Appropriateness rates for the studies were determined using information from existing literature (clinical decision rules and society guidelines). Where pretest probability was not performed, it was calculated by the authors. After ED health care provider education regarding appropriateness guidelines through a dedicated lecture and question-and-answer session, appropriateness rates for another 100 consecutive CTPA ordered by the ED were calculated.

RESULTS

In the preeducational intervention, 1% of patients had Wells scores performed, 65% were women, and 29% were age <40 years. Before CTPA, 40% patients had d-dimer testing, 15% of patients had a "negative" d-dimer, 17% had alternative explanations for chest pain, and 76% had low or intermediate pretest probability. Appropriateness rates for CTPA was 7%, and 8% of studies were positive. Postintervention, no Wells scores were performed, 59% were women, and 34% <40 years. Before CTPA, 32% of patients had d-dimer, 16% had a "negative" d-dimer, 22% had alternative explanations for chest pain, and 84% had low or intermediate pretest probability. The appropriateness rate for CTPA was 6% and 10% of studies were positive.

CONCLUSION

A single educational intervention had no effect on appropriate utilization rates for CTPA. Repeated and sustained educational interventions may help improve imaging ordering pathways through the ED and other departments.

Associations between presence of relevant information in referrals to radiology and prevalence rates in patients with suspected pulmonary embolism

RATIONALE AND OBJECTIVES

The purpose of this study was to assess if the presence of information including the pretest probability (Wells score), other known risk factors, and symptoms given on referrals for computed tomography (CT) pulmonary angiography correlated with prevalence rates for pulmonary embolism (PE). Also, to evaluate for differences between a university and a regional hospital setting regarding patient characteristics, amount of relevant information provided on referrals, and prevalence rates for pulmonary embolism.

MATERIALS AND METHODS

Retrospective review of all consecutive referrals (emergency room, inpatient, and outpatient) for CT performed on children and adults for suspected PE from two sites: a tertiary (university) hospital (site 1) and a secondary (regional) hospital (site 2) over a 5-year period.

RESULTS

The overall prevalence rate was 510/3641 or 14% of all referrals. Significantly higher number of males had a positive CT compared to women (18% versus 12%, P < .001). Although no statistically significant relationship between a greater amount of relevant information on the referral and the probability for positive finding existed, a slight trend was noted (P = .09). In two categories, "hypoxia" and "signs of deep vein thrombosis," the presence of this information conferred a higher probability for pulmonary embolism, P < .001. In the categories, "chest pain," "malaise," and "smoker/chronic obstructive pulmonary disease", the absence of information conferred a higher probability for pulmonary embolism.

CONCLUSIONS

The amount of relevant clinical information on the request did not correlate with prevalence rates, which may reflect a lack of documentation on the part of emergency physicians who may use a "gestalt" approach. Request forms likely did not capture all relevant patient risks and many factors may interact with each other, both positively and negatively. Pretest probability estimations were rarely performed, despite their inclusion in major society guidelines.

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.

D-dimer in the diagnostic workup of suspected pulmonary thrombo-embolism at high altitude

BACKGROUND

Pulmonary thrombo-embolism (PTE) is relatively common in high altitude areas where radiological diagnostic facilities are usually not available. So this study was undertaken to use the results of D-dimer assay to determine the need for imaging studies in patients suspected of having PTE at high altitude.

METHODS

A total of 101 patients at an altitude of > 3,000 m suspected of having PTE were evacuated. D-dimer and imaging studies were carried out to confirm the diagnosis.

RESULTS

A total of 101 patients suspected of having PTE underwent D-dimer level estimation and imaging studies for PTE. Sixty-eight of these had negative findings) on D-dimer assay. All these patients with negative findings on D-dimer assay had negative findings on pulmonary imaging studies also. So this test is very sensitive with very high negative predictive value (NPV). Whereas, 17 out of 33 patients positive for D-dimer, had positive findings on imaging studies, indicating a relatively less specific test.

CONCLUSION

Clinical assessment in combination with D-dimer assay can be used for timely differentiation of PTE from other conditions such as high altitude pulmonary oedema (HAPO) especially at isolated high altitude areas/military posts, so that patients could be evacuated as early as possible by fastest means to save the precious lives and in hospital settings this test identifies patients to whom anticoagulant therapy should not be given or patients who should not be subjected to invasive imaging tests.

Critical issues in the evaluation and management of adult patients presenting to the emergency department with suspected pulmonary embolism

This clinical policy from the American College of Emergency Physicians is the revision of a 2003 clinical policy on the evaluation and management of adult patients presenting with suspected pulmonary embolism (PE).(1) A writing subcommittee reviewed the literature to derive evidence-based recommendations to help clinicians answer the following critical questions: (1) Do objective criteria provide improved risk stratification over gestalt clinical assessment in the evaluation of patients with possible PE? (2) What is the utility of the Pulmonary Embolism Rule-out Criteria (PERC) in the evaluation of patients with suspected PE? (3)What is the role of quantitative D-dimer testing in the exclusion of PE? (4) What is the role of computed tomography pulmonary angiogram of the chest as the sole diagnostic test in the exclusion of PE? (5) What is the role of venous imaging in the evaluation of patients with suspected PE? (6) What are the indications for thrombolytic therapy in patients with PE? Evidence was graded and recommendations were given based on the strength of the available data in the medical literature.

The current state of practice in the diagnosis of venous thromboembolism at an academic medical center

Evidence-based guidelines for the diagnosis of venous thromboembolism (VTE) have been recommended, yet the adoption of such guidelines into daily practice is unknown. The purpose of this study was to describe the current practices in the diagnosis of VTE. Medical records of 1161 adult patients who underwent lower extremity venous duplex scans (VDS), chest computerized tomographic (CT) angiography, or ventilation and perfusion (V/Q) scans during a 6-month period were retrospectively reviewed in an academic medical center. Patients who were first diagnosed by CT or V/Q scan still underwent a VDS. Nine patients at high risk had incomplete CT scans, yet no further tests were performed. Five pregnant patients had CT scans as the initial test instead of being screened with VDS or V/Q scanning. Inappropriate use of imaging tests was documented. The recommended guidelines of using clinical probability and D-dimer as the initial screening tests for VTE diagnosis were underused.

Cost-effective diagnostic strategies in patients with a high, intermediate, or low clinical probability of pulmonary embolism

Rapid quantitative D-dimer assays (DD), lower extremity venous duplex ultrasonography (US), and multislice computed tomographic (CT) angiography have been shown to have adequate sensitivities and specificities for diagnostic purpose. The purpose of this study was to evaluate cost-effectiveness of diagnostic strategies for pulmonary embolism (PE) in patients with a high, intermediate, or low clinical probability of PE. A formal cost-effectiveness analysis for the diagnosis of PE was performed. The main outcome measure for effectiveness was 3-month expected survival. The strategy of DD followed by CT was cost-effective and had the lowest cost per life saved for all patients suspected with PE. The conventional strategy including ventilation and perfusion lung scanning followed by pulmonary angiography (PA) or CT was not cost-effective. The leg US after CT was not also cost-effective. In clinical practice, the individual patient's condition should be considered when choosing appropriate diagnostic tests.

Advances in the detection of pulmonary embolism

BACKGROUND

Diagnosing or excluding pulmonary embolism is a complex challenge. Many diagnostic instruments can be used in patients with clinically suspected pulmonary embolism nowadays, all with their own (dis-)advantages. Methods/objectives: In this review, these (dis-)advantages are discussed for the following diagnostic instruments: clinical probability assessment, D-dimer concentration, the combination of clinical probability assessment and D-dimer concentration, bilateral compression ultrasonography, ventilation/perfusion scintigraphy, computerized tomographic pulmonary angiography, pulmonary angiography and magnetic resonance pulmonary angiography. A diagnostic strategy, which can be adjusted to local facilities, is provided and discussed.

CONCLUSION

Using combinations of some of these diagnostic tools, many diagnostic strategies are possible and every hospital should make its own local protocol suited for the local situation.