Detection Of Acute Pulmonary Embolism Research Articles

CT pulmonary angiography in the emergency department: utilization and positivity rates during various phases of the COVID-19 pandemic.

To evaluate the trends in utilization and results of computed tomography pulmonary angiography (CTPA study) for detection of acute pulmonary embolism (PE) in the Emergency Department (ED) during different phases of COVID-19 public health emergency. We conducted a retrospective review of CTPA studies ordered through our ED in the months of March through May during five consecutive years from 2019 to 2023, designated as pre-pandemic, early, ongoing, recovery, and post-pandemic periods respectively. Collected characteristics included patient age, patient sex, and result of the study. The utilization of CTPA studies for ED patients increased during the early, ongoing, and recovery periods. CTPA study utilization in the post-pandemic period was not significantly different from the pre-pandemic period (p = 0.08). No significant difference in CTPA study utilization was noted in the other periods when stratified by age group or sex, compared to the pre-pandemic period. The positivity rate of acute PE in ED patients was not significantly different in other periods compared to the pre-pandemic period. At our institution, the utilization and positivity rates of CTPA studies for the ED patients were not significantly different in the post-pandemic period compared to the pre-pandemic period. While studies spanning a larger timeframe and involving multiple institutions are needed to test the applicability of this observation to a wider patient population beyond our defined post-pandemic period, we conclude that our study provides some confidence to the ordering provider and the radiologist in embracing the end of COVID-19 public health emergency by the WHO and the United States HHS with respect to CTPA studies.

Detection of acute pulmonary embolism using native repeated magnetic resonance imaging acquisitions under free-breathing and without respiratory or cardiac gating. A diagnostic accuracy study

ObjectivesComputed tomography pulmonary angiography (CTPA) is the gold standard diagnostic method for patients with suspected pulmonary embolism (PE), but it has its drawbacks, including exposure to ionizing radiation and iodinated contrast agent. The present study aims to evaluate the diagnostic performance of our in-house developed non-contrast MRI protocol for PE diagnosis in reference to CTPA. Methods107 patients were included, all of whom underwent MRI immediately before or within 36 hours after CTPA. Additional cases examined only with MRI and a negative result were added to reach a PE prevalence of approximately 20%. The protocol was a non-contrast 2D steady-state free precession (SSFP) sequence under free-breathing, without respiratory or cardiac gating, and repeated five times to capture the vessels at different breathing/cardiac phases. The MRIs were blinded and read by two radiologists and the results were compared to CTPA. ResultsOf the 243 patients included, 47 were positive for PE. Readers 1 and 2 demonstrated 89% and 87% sensitivity, 100% specificity, 98% accuracy and Cohen’s kappa of 0.88 on patient level. In the per embolus comparison, readers 1 and 2 detected, 60 and 59/61 (98, 97%) proximal, 101 and 94/113 (89, 83%) segmental, and 5 and 2/32 (16, 6%) subsegmental emboli, resulting in 81 and 75% sensitivity respectively. ConclusionThe repeated 2D SSFP can reliably be used for the diagnosis of acute PE at the proximal and segmental artery levels.

Retrospective batch analysis to evaluate the diagnostic accuracy of a clinically deployed AI algorithm for the detection of acute pulmonary embolism on CTPA

PurposeTo generate and extend the evidence on the clinical validity of an artificial intelligence (AI) algorithm to detect acute pulmonary embolism (PE) on CT pulmonary angiography (CTPA) of patients suspected of PE and to evaluate the possibility of reducing the risk of missed findings in clinical practice with AI-assisted reporting.MethodsConsecutive CTPA scan data of 3316 patients referred because of suspected PE between 24-2-2018 and 31-12-2020 were retrospectively analysed by a CE-certified and FDA-approved AI algorithm. The output of the AI was compared with the attending radiologists’ report. To define the reference standard, discordant findings were independently evaluated by two readers. In case of disagreement, an experienced cardiothoracic radiologist adjudicated.ResultsAccording to the reference standard, PE was present in 717 patients (21.6%). PE was missed by the AI in 23 patients, while the attending radiologist missed 60 PE. The AI detected 2 false positives and the attending radiologist 9. The sensitivity for the detection of PE by the AI algorithm was significantly higher compared to the radiology report (96.8% vs. 91.6%, p < 0.001). Specificity of the AI was also significantly higher (99.9% vs. 99.7%, p = 0.035). NPV and PPV of the AI were also significantly higher than the radiology report.ConclusionThe AI algorithm showed a significantly higher diagnostic accuracy for the detection of PE on CTPA compared to the report of the attending radiologist. This finding indicates that missed positive findings could be prevented with the implementation of AI-assisted reporting in daily clinical practice.Critical relevance statementMissed positive findings on CTPA of patients suspected of pulmonary embolism can be prevented with the implementation of AI-assisted care.Key pointsThe AI algorithm showed excellent diagnostic accuracy detecting PE on CTPA.Accuracy of the AI was significantly higher compared to the attending radiologist.Highest diagnostic accuracy can likely be achieved by radiologists supported by AI.Our results indicate that implementation of AI-assisted reporting could reduce the number of missed positive findings.Graphical abstract

Free-breathing Arterial Spin Labeling MRI for the Detection of Pulmonary Embolism.

Background Arterial spin labeling (ASL) MRI can be used to assess organ perfusion but has yet to be implemented for perfusion evaluation of the lung. Purpose To evaluate pseudo-continuous ASL (PCASL) MRI for the detection of acute pulmonary embolism (PE) and its potential as an alternative to CT pulmonary angiography (CTPA). Materials and Methods Between November 2020 and November 2021, 97 patients (median age, 61 years; 48 women) with suspected PE were enrolled in this prospective study. PCASL MRI was performed within a 72-hour period following CTPA under free-breathing conditions and included three orthogonal planes. The pulmonary trunk was labeled during systole, and the image was acquired during diastole of the subsequent cardiac cycle. Additionally, multisection, coronal, balanced, steady-state free-precession imaging was carried out. Two radiologists blindly assessed overall image quality, artifacts, and diagnostic confidence (five-point Likert scale, 5 = best). Patients were categorized as positive or negative for PE, and a lobe-wise assessment in PCASL MRI and CTPA was conducted. Sensitivity and specificity were calculated on a patient level with the final clinical diagnosis serving as the reference standard. Interchangeability between MRI and CTPA was also tested with use of an individual equivalence index (IEI). Results PCASL MRI was performed successfully in all patients with high scores for image quality, artifact, and diagnostic confidence (κ ≥ .74). Of the 97 patients, 38 were positive for PE. PCASL MRI depicted PE correctly in 35 of 38 patients with three false-positive and three false-negative findings, resulting in a sensitivity of 35 of 38 patients (92% [95% CI: 79, 98]) and a specificity of 56 of 59 patients (95% [95% CI: 86, 99]). Interchangeability analysis revealed an IEI of 2.6% (95% CI: 1.2, 3.8). Conclusion Free-breathing pseudo-continuous arterial spin labeling MRI depicted abnormal lung perfusion caused by acute pulmonary embolism and may be useful as a contrast material-free alternative to CT pulmonary angiography for selected patients. German Clinical Trials Register no. DRKS00023599 © RSNA, 2023.

Value of low-keV virtual monoenergetic plus dual-energy computed tomographic imaging for detection of acute pulmonary embolism.

To compare diagnostic values between the 40 keV virtual monoenergetic plus (40 keV VMI+) dual source dual energy computed tomography (DSDECT) pulmonary angiography images and the standard mixed (90 and 150 kV) images for the detection of acute pulmonary embolism (PE). Chest DSDECTs of 64 patients who were suspected of having acute PE were retrospectively reviewed by two independent reviewers. The assessments of acute PE of all patients on a per-location basis were compared between the 40 keV VMI+ and the standard mixed datasets (reference standard) with a two-week interval. This study consisted of 64 patients (33 women and 31 men; mean age, 60.2 years; range 18-90 years), with a total of 512 locations. The interobserver agreement (Kappa) for detection of acute PE using the 40 keV VMI+ images and the standard mixed CT images were 0.7478 and 0.8750 respectively. The area under receiver operating characteristics (AuROC) for diagnosis of acute PE using the 40 keV VMI+ was 0.882. Four locations (0.78%) revealed a false negative result. Hypodense filling defects were identified in twelve locations (1.95%) in the 40 keV VMI+ images but had been interpreted as a negative study in the standard mixed CT images. The repeated reviews revealed that each location contained a hypodense filling defect but was overlooked on the standard mixed CT images. Low-energy VMI + DSDECT images have beneficial in improving the diagnostic value of acute PE in doubtful or disregarded standard mixed images.

Abstract 15880: Detection of an Acute Pulmonary Embolism in the Home Bed Using Adherence-Independent Home Monitoring

Acute pulmonary embolism classically presents with dyspnea, tachypnea, and hypoxia, but self-recognition of symptoms and clinical findings is often challenging. This is particularly true in elder patients or those with cognitive impairments. Digital health technologies offer opportunities to remotely detect pre-symptomatic illness. We present a prodrome of an acute pulmonary embolism as it emerges in the home during continuous respiratory monitoring using a non-contact adherence-independent home bed sensor. The patient is an 85-year-old woman who is morbidly obese, has limited mobility, and multiple comorbidities including a recent diagnosis of atrial fibrillation for which she was prescribed anticoagulation but has not yet initiated. As part of an observational study, nocturnal respiratory rates (NRR) were longitudinally monitored in her home bed using a non-contact, adherence-independent bed sensor. Eight days prior to admission, increasing NRR prompted a patient call to family who noted no acute symptomatic changes. During the call it was discovered she had not been started on apixaban. On subsequent days, persistently elevated NRR prompted a second phone call 4 days prior to admission (PTA), where again no acute symptoms were noted. Anticoagulation still had not been started at that time. NRR worsened further on days following the second call prompting a home visit by an RN who found the patient dyspneic, tachypneic in the high 20s, and hypoxic with oxygen saturations in the 80s, prompting a transfer to the emergency department for further evaluation. She was eventually diagnosed with an acute pulmonary embolism. After a week-long hospitalization, the patient was discharged on adequate anticoagulation therapy.This case suggests that adherence-independent home bed monitoring of nocturnal respiratory rate may enable early detection of chronic volume overload and acute pulmonary embolism, potentially facilitating early intervention.

Head-to-head comparison of ventilation/perfusion single photon emission computed tomography/computed tomography and multidetector computed tomography angiography for the detection of acute pulmonary embolism in clinical practice.

Computed tomography angiography (CTA) and ventilation/perfusion (V/Q) single photon emission computed tomography/CT (SPECT/CT) images have been widely used to detect PE, but few studies have performed a direct comparison between them. We aimed to evaluate the performance of these tests in the same group of patients, selected from the routine practice of a general hospital. Patients with suspected acute PE were prospectively submitted to CTA and V/Q SPECT/CT. General radiologists and nuclear physicians, respectively, interpreted the images. Data regarding age, sex, time between examinations, symptoms, and Wells score were also recorded. The final diagnosis was decided through a consensus among the clinicians, taking into account clinical, laboratory, follow-up, and all imaging procedures data. Twenty-eight patients (15 male, 13 female, and median age of 51.5years) were studied. Median duration of the onset of symptoms was 4 (1-14)days, and the median Wells score was 3.5 (1.5-6). Sensitivity, specificity, positive and negative predictive values, and accuracy were 84.6%, 80.0%, 78.6%, 85.7%, and 82.1% for V/Q SPECT/CT, and 46.1%, 100%, 100%, 68.2%, and 75.0% for CTA. The overall agreement between the methods was 57.1%. Of the 22 patients with negative CTA, 10 (45.4%) had positives V/Q SPECT/CT and seven of them classified as true positives. Our results suggest that V/Q SPECT/CT is more sensitive and accurate than CTA when interpreted by general radiologists and nuclear medicine physicians.

Increased Incidence of Acute Pulmonary Embolism in Emergency Department Patients During the COVID‐19 Pandemic

Early detection of acute pulmonary embolism (PE) in patients with SARS-CoV-2 infection is integral to the clinical management of these patients. Many recently published studies have evaluated incidence of PE in hospitalized patients with COVID-191-9 , however there is relatively limited data describing patients with SARS-CoV-2 infection and concomitant diagnosis of acute PE upon initial presentation. Therefore, the purpose of this study is to (i) evaluate the incidence of acute pulmonary embolism (PE) in patients undergoing computed tomography pulmonary angiography (CTPA) in the emergency department (ED) across six hospitals in New York City during the height of the COVID-19 pandemic compared to a non-pandemic period, and (ii) compare the characteristics and early outcomes of patients presenting with PE during the pandemic (n=87) to patients presenting with PE during a non-pandemic period (n=34).

Detection of Acute Pulmonary Embolism by Electrical Impedance Tomography and Saline Bolus Injection

Detection of Acute Pulmonary Embolism by Electrical Impedance Tomography and Saline Bolus Injection

Diagnostic Accuracy of Dual-Energy CT in Detection of Acute Pulmonary Embolism: A Systematic Review and Meta-Analysis.

In this systematic review and meta-analysis, we aimed to investigate the accuracy of dual-energy computed tomography (DECT) in the detection of acute pulmonary embolism (PE). We searched Medline (via PubMed), EBSCO, Web of Science, Scopus, and the Cochrane Library for relevant published studies. We selected studies assessing the accuracy of DECT in the detection of PE. Quality assessment of bias and applicability was conducted using the Quality of Diagnostic Accuracy Studies-2 tool. Meta-analysis was performed to calculate mean estimates of sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR). The summary receiver operating characteristic (sROC) curve was drawn to get the Cochran Q-index and the area under the curve (AUC). Seven studies were included in our systematic review. Of the 182 patients included, 108 patients had PEs. The pooled analysis showed an overall sensitivity and specificity of 88.9% (95% confidence interval [CI]: 81.4%-94.1%) and 94.6% (95% CI: 86.7%-98.5%), respectively. The pooled PLR was 8.186 (95% CI: 3.726-17.986), while the pooled NLR was 0.159 (95% CI: 0.093-0.270). Cochran-Q was 0.8712, and AUC was 0.935 in the sROC curve. Dual-energy computed tomography shows high sensitivity, specificity, and diagnostic accuracy in the detection of acute PE. The high PLR highlights the high clinical importance of DECT as a prevalence-independent, rule-in test. Studies with a larger sample size with standardized reference tests are still needed to increase the statistical power of the study and support these findings.

Low-dose CT Angiography in the Detection of Acute Pulmonary Embolism: Validation in an Obese Population

Low-dose CT Angiography in the Detection of Acute Pulmonary Embolism: Validation in an Obese Population

Computer-assisted detection of acute pulmonary embolism at CT pulmonary angiography in children and young adults: a diagnostic performance analysis.

Background To diagnose pulmonary embolism (PE) in children and adults since evaluating tiny pulmonary vasculature beyond segmental level is a challenging and demanding task with thousands of images. Purpose To evaluate the effect of computer-assisted detection (CAD) on acute PE on CTPA in children and young adults by readers with varying experience levels. Material and Methods Six radiologists were retrospectively divided into three groups according to experience levels and assessed the CTPA studies on a per-emboli basis. All readers identified independently the PE presence, and ranked diagnostic confidence on a 5-point scale with and without CAD. Reading time, sensitivities, specificities, accuracies, positive predictive values (PPVs), and negative predictive values (NPVs) were calculated for each reading. Results The sensitivities and NPVs differed significantly in most readers ( P = 0.004, 0.001, 0.010, 0.010, and 0.012 for sensitivities and P = 0.011, 0.003, 0.016, 0.017, and 0.019 for NPVs) except for reader 6 ( P = 0.148 and 0.165, respectively), and the accuracies of all readers differed significantly (all P &lt; 0.05) in peripheral PE (beyond segmental level) detection readings with CAD versus without CAD between two reading methods. The overall time using CAD was longer than those without CAD (76.6 ± 54.4 s vs. 49.4 ± 17.7 s, P = 0.000) for all readers. Significant differences were found for confidence scores in inter-group measurements with CAD ( P = 0.045) and without CAD ( P &lt; 0.001). Conclusion At the expense of longer reading time, the use of the CAD algorithms improves sensitivities, NPVs, and the accuracies of readers in peripheral PE detection, especially for readers with a poor level of interpretation experience.

Diagnostic accuracy of magnetic resonance angiography for acute pulmonary embolism - a systematic review and meta-analysis.

The aim of this meta-analysis was to evaluate the diagnostic accuracy of magnetic resonance angiography (MRA) for acute pulmonary embolism (PE). A systematic literature search was conducted that included studies from January 2000 to August 2015 using the electronic databases PubMed, Embase and Springer link. The summary receiver operating characteristic (SROC) curve, sensitivity, specificity, positive likelihood ratios (PLR), negative likelihood ratios (NLR), and diagnostic odds ratio (DOR) as well as the 95 % confidence intervals (CIs) were calculated to evaluate the diagnostic accuracy of MRA for acute PE. Meta-disc software version 1.4 was used to analyze the data. Five studies were included in this meta-analysis. The pooled sensitivity (86 %, 95 % CI: 81 % to 90 %) and specificity (99 %, 95 % CI: 98 % to 100 %) demonstrated that MRA diagnosis had limited sensitivity and high specificity in the detection of acute PE. The pooled estimate of PLR (41.64, 95 % CI: 17.97 to 96.48) and NLR (0.17, 95 % CI: 0.11 to 0.27) provided evidence for the low missed diagnosis and misdiagnosis rates of MRA for acute PE. The high diagnostic accuracy of MRA for acute PE was demonstrated by the overall DOR (456.51, 95 % CI: 178.38 - 1168.31) and SROC curves (AUC = 0.9902 ± 0.0061). MRA can be used for the diagnosis of acute PE. However, due to limited sensitivity, MRA cannot be used as a stand-alone test to exclude acute PE.

40-Year-Old Woman With Breathlessness and Fatigue

40-Year-Old Woman With Breathlessness and Fatigue

Detection of pulmonary embolism with free-breathing dynamic contrast-enhanced MRI.

To evaluate the use of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) during free breathing for the detection of acute pulmonary embolism (PE). Eighteen subjects underwent free-breathing DCE MRI at 1.5T, eight of whom were patients with acute PE, as confirmed by routine computed tomography pulmonary angiography (CTPA). The remaining 10 subjects were healthy volunteers with no history or signs of pulmonary disease. From all DCE MRI data, maps of relative signal enhancement were calculated and assessed for the presence or absence of perfusion defects in each lung by two readers. Interreader variability, sensitivity, and specificity of free-breathing DCE MRI for the detection of PE were calculated using CTPA as the gold standard. Of the 16 patient's lungs, 15 were affected by acute PE according to CTPA. In patients and volunteers, DCE MRI sensitivity was 93% and 87% for readers 1 and 2, with specificities of 95% and 90%, respectively. Interreader agreement was substantial, with κ = 0.77 (95% confidence interval: 0.44-1.0). Free-breathing DCE MRI may have potential use for the assessment of PE, and does not require patient cooperation in breath-holding.

Detection of acute pulmonary embolism: feasibility of diagnostic accuracy of MRI using a stepwise protocol

Multidetector computed tomography (MDCT) has become the imaging method of choice in patients suspected of having pulmonary embolism (PE) but has the inherent limitation of radiation dose and the side effects of contrast agents. The purpose of the study was to assess the feasibility of a stepwise MRI protocol in the clinical setting of acute PE. The stepwise approach should make it possible to diagnose acute PE in critically ill patients using fast MR sequences and included the option to add comprehensive sequences when patients were stable. Forty-five patients with acute PE (26 men, 19 women; 41 ± 16 years) were included in this prospective study. The diagnosis was initially confirmed by MDCT as gold standard. MRI at 1.5 T was subsequently performed without any delay in medical treatment. The MRI protocol proceeded stepwise from robust to detailed imaging techniques (i.e., from TrueFISP and single shot HASTE sequence to MR perfusion and 3D-MR angiography) if the patient was able to tolerate additional imaging time. Diagnostic accuracy was evaluated on the central (lobar) and peripheral (segmental) levels. The complete MR protocol was applied in 40 of the 45 patients (88 %). In the remaining five patients with severe dyspnea the diagnosis of acute PE was established by using fast TrueFISP sequences that were insensitive to respiratory movement. All five patients suffered from a major central PE. Highest sensitivity was achieved by MR perfusion (lobar, 98 %; segmental, 95 %). Real-time TrueFISP and MR angiography showed the highest specificity (lobar, 90-100 %; segmental, 95-97 %). The combination of all MR sequences matched closely the results of MDCT (lobar: sensitivity 98 %, specificity 100 %; segmental: sensitivity 95 %, specificity 97 %). MRI using a stepwise protocol is a promising approach for diagnosing acute PE. The protocol can be tailored for dyspneic patients with central PE using real-time MRI sequences. The diagnostic accuracy for peripheral PE can be improved by using combined MR techniques, achieving comparable results to MDCT.

Computed Tomography Pulmonary Angiography in Acute Pulmonary Embolism

To assess the effect of computer-assisted detection (CAD) on diagnostic accuracy, reader confidence, and reading time when used as a concurrent reader for the detection of acute pulmonary embolism in computed tomography pulmonary angiography. In this institutional review board-approved retrospective study, 6 observers with varying experience evaluated 158 negative and 38 positive consecutive computed tomography pulmonary angiographies (mean patient age 60 y; 115 women) without and with CAD as a concurrent reader. Readers were asked to determine the presence of pulmonary embolism, assess their diagnostic confidence using a 5-point scale, and document their reading time. Results were compared with an independent standard established by 2 readers, and a third chest radiologist was consulted in case of discordant findings. Using logistic regression for repeated measurements, we found a significant increase in readers' sensitivity (P<0.001) without loss of specificity (P=0.855) with the effects being reader dependent (P<0.001). Sensitivities varied from 68% to 100% without CAD and from 76% to 100% with CAD. A 2-way analysis of variance showed a small but significant decrease in reading time (P<0.001), with the duration varying between 24 and 208 seconds without CAD and between 17 and 196 seconds with CAD, and a significant increase in readers' confidence scores using CAD as a concurrent reader (P<0.001). CAD as a concurrent reader has the potential to increase readers' sensitivity and confidence with a decrease in reading time without loss of specificity. The differences between readers, however, require further evaluation of CAD as a concurrent reader in a larger trial before stronger conclusions can be drawn.

Clot burden score in the evaluation of right ventricular dysfunction in acute pulmonary embolism: Quantifying the cause and clarifying the consequences

IntroductionPulmonary angiography by computed tomography (CT) is the method of choice for the detection of acute pulmonary embolism (PE). Studies have shown that the severity of PE can be estimated by clot burden scores. ObjectiveTo evaluate the correlation between an angiographic clot burden score (Qanadli score–QS) and parameters of right ventricular dysfunction (RVD) in patients admitted for PE. MethodsWe performed a retrospective study of 107 patients (60% female) admitted to an intensive care unit for PE (intermediate/high risk) between January 1, 2007 and September 30, 2011. Images from 16-slice multidetector CT angiography were reviewed in 102 patients and the QS calculated. Based on a cut-off of 18 points established by ROC curve analysis, two groups were formed (A<18 points vs. B≥18 points) and the clinical, laboratory, ECG, echocardiographic and CT angiography parameters were compared. The statistical analysis was performed using SPSS. ResultsThe overall mean age was 61.4 years. With regard to symptoms at admission, there was a greater prevalence in group B of fatigue, chest pain and syncope (p=0.017), with higher Geneva and Wells scores and shock index.In terms of ECG parameters, heart rate and percentage of right bundle branch block, T-wave inversion (V1–V3) and S1Q3T3 pattern (p=0.034) were higher in group B, as was the ECG score (p=0.009).Laboratory tests revealed that group B had higher troponin and d-dimers, with lower creatinine clearance by the MDRD formula (p=0.020) and PO2/FiO2 ratio. Echocardiography showed higher pulmonary artery systolic pressure in group B, and CT angiography revealed larger right ventricular (RV) diameters and higher RV/LV ratio (p=0.002), and greater superior vena cava, azygos vein and coronary sinus diameters in this group. Pulmonary artery (PA) diameter and the PA/aorta ratio were similar. Interventricular septal bowing and reflux of contrast into the inferior vena cava (p=0.001) were greater in group B, and QS>18 was an independent predictor of RVD (RV/LV ratio>1) (OR: 10.85; p<0.001) (area under the curve on ROC analysis: 0.79; p<0.001).The percentage of patients receiving fibrinolytic treatment was higher in group B (p=0.045), and in-hospital mortality was similar in both groups (overall 4.9%). ConclusionsQS>18 points proved to be an independent predictor of RVD in PE, and correlated linearly with variables associated with higher morbidity and mortality.

O valor da carga embólica na avaliação de disfunção ventricular direita no tromboembolismo pulmonar agudo: quantificando a causa e clarificando as consequências

IntroductionPulmonary angiography by computed tomography (CT) is the method of choice for the detection of acute pulmonary embolism (PE). Studies have shown that the severity of PE can be estimated by clot burden scores. ObjectiveTo evaluate the correlation between an angiographic clot burden score (Qanadli score - QS) and parameters of right ventricular dysfunction (RVD) in patients admitted for PE. MethodsWe performed a retrospective study of 107 patients (60% female) admitted to an intensive care unit for PE (intermediate/high risk) between January 1, 2007 and September 30, 2011. Images from 16-slice multidetector CT angiography were reviewed in 102 patients and the QS calculated. Based on a cut-off of 18 points established by ROC curve analysis, two groups were formed (A<18 points vs. B ≥18 points) and the clinical, laboratory, ECG, echocardiographic and CT angiography parameters were compared. The statistical analysis was performed using SPSS. ResultsThe overall mean age was 61.4 years. With regard to symptoms at admission, there was a greater prevalence in group B of fatigue, chest pain and syncope (p=0.017), with higher Geneva and Wells scores and shock index.In terms of ECG parameters, heart rate and percentage of right bundle branch block, T-wave inversion (V1-V3) and S1Q3T3 pattern (p=0.034) were higher in group B, as was the ECG score (p=0.009).Laboratory tests revealed that group B had higher troponin and d-dimers, with lower creatinine clearance by the MDRD formula (p=0.020) and PO2/FiO2 ratio. Echocardiography showed higher pulmonary artery systolic pressure in group B, and CT angiography revealed larger right ventricular (RV) diameters and higher RV/LV ratio (p=0.002), and greater superior vena cava, azygos vein and coronary sinus diameters in this group. Pulmonary artery (PA) diameter and the PA/aorta ratio were similar. Interventricular septal bowing and reflux of contrast into the inferior vena cava (p=0.001) were greater in group B, and QS>18 was an independent predictor of RVD (RV/LV ratio>1) (OR: 10.85; p<0.001) (area under the curve on ROC analysis: 0.79; p<0.001). The percentage of patients receiving fibrinolytic treatment was higher in group B (p=0.045), and in-hospital mortality was similar in both groups (overall 4.9%). ConclusionsQS >18 points proved to be an independent predictor of RVD in PE, and correlated linearly with variables associated with higher morbidity and mortality.

Détection de l’embolie pulmonaire aiguë : apport du scanner X faible dose à la tomoscintigraphie pulmonaire de ventilation et de perfusion

Ventilation and perfusion (V/Q) lung SPECT, performed according to the new recommendations of European Association of Nuclear Medicine (EANM), is a first-line examination for the detection of acute pulmonary embolism. Since low-dose CT scan acquisitions may be recorded during the same examination on hybrid cameras, the corresponding additional information should be assessed. The aim of this study is to compare the diagnostic information provided by lung V/Q SPECT, alone and combined with a low-dose CT scan. Each analysis is performed by two readers; one is more experienced (assistant, A) and one less (interne, I). ResultsThe addition of low-dose CT Scan to lung V/Q SPECT: (1) seldom changes the main diagnostic answer in example the presence or absence of pulmonary embolism (2% for A and 6% for I); (2) frequently gives more minor additional informations, 69% for A and 79% for I (localisation of the involved segments, non embolic pleuroparenchymal abnormalities…) and (3) is associated with a concordance of 87% between the two readers with regard to the final diagnosis of pulmonary embolism (84% for SPECT without CT scan). Seventy-nine percent of these discordances were associated with a low quality of ventilation images. ConclusionWhen added to V/Q lung SPECT, low-dose CT scan commonly provides an additional diagnostic information, without affecting interobserver reproducibility, but this information is generally minor without impact on the diagnosis of pulmonary embolism.