Computed Tomography Pulmonary Angiography Research Articles

Avoidable Overuse of Computed Tomography Pulmonary Angiography (CTPA) in Patients with Suspected Acute Pulmonary Thromboembolism (PTE): The Role of Clinical Prediction Rules and D-Dimer Assay

Background: Computed tomography pulmonary angiography (CTPA) is an imaging technique widely used in the diagnosis of acute pulmonary thromboembolism (PTE). Despite its disadvantages and potential risks, the overuse of CTPA has been a growing concern over the past decades. Objectives: The objective of this study was to investigate the rate of avoidable overuse of CTPA in patients with suspected PTE and to identify factors contributing to this overuse. The study aimed to highlight the importance of proper training for physicians in using validated diagnostic algorithms to minimize the overuse of CTPA and improve patient outcomes. Methods: In a cross-sectional study conducted between April 2016 and March 2019 at Shariati Hospital at Tehran University of Medical Sciences (TUMS), 1058 patients underwent CTPA due to suspected PTE. Wells scores were calculated retrospectively for all patients. The study defined avoidable overuse of CTPA as an imaging request without prior D-dimer testing or ignoring a negative D-dimer result in patients with low clinical pre-test probability. Results: Two hundred and seventy-three patients were excluded from the study due to unavailable documentation or pregnancy. Among the included 785 patients, 139 (17.7%) revealed PTE on CTPA. Based on the Wells scores, 480 patients were identified as the “PTE-unlikely” group. In this group, 299 patients (62.3%) underwent CTPA directly despite recommendations to order a D-dimer test first. Of these patients, 281 (94%) cases showed negative results. Moreover, CTPA was performed inappropriately in 52 “PTE-unlikely” cases despite negative D-dimer serum levels, and only one patient was diagnosed with PTE. Conclusions: The study revealed that 44.7% of the CTPA requests for patients with suspected PTE were avoidable, indicating the need for better adherence to current diagnostic guidelines to reduce unnecessary radiologic investigations and improve patient care.

A Rare Case of Tuberculous Constrictive Pericarditis Due to Disseminated Tuberculosis with Response to Anti-tuberculosis Chemotherapy and Steroids in a Developed City State

A 27-year-old man presented with a 1-week history of atypical chest pain and sinus tachycardia. His physical examination was unremarkable. His resting ECG showed sinus tachycardia with widespread T-wave inversion. His initial blood tests show mildly raised troponin T and inflammatory markers and marked raised D-dimer. A CT pulmonary angiogram was performed to exclude pulmonary embolism but incidentally revealed an anterior mediastinal mass. A transthoracic echocardiogram and cardiac MRI showed features of constrictive pericarditis. A video-assisted thoracoscopic surgical biopsy of the anterior mediastinal mass showed thymic tissue with necrotising granulomatous inflammation and an acid-fast bacilli culture was positive to tuberculosis infection. The patient was started on anti-tuberculosis chemotherapy and a 6-week tapering course of oral steroids. A repeat cardiac MRI performed after 6 weeks of treatment showed a significant response to treatment with resolution of constrictive physiology.

Anatomically aware dual-hop learning for pulmonary embolism detection in CT pulmonary angiograms

Pulmonary Embolisms (PE) represent a leading cause of cardiovascular death. While medical imaging, through computed tomographic pulmonary angiography (CTPA), represents the gold standard for PE diagnosis, it is still susceptible to misdiagnosis or significant diagnosis delays, which may be fatal for critical cases. Despite the recently demonstrated power of deep learning to bring a significant boost in performance in a wide range of medical imaging tasks, there are still very few published researches on automatic pulmonary embolism detection. Herein we introduce a deep learning based approach, which efficiently combines computer vision and deep neural networks for pulmonary embolism detection in CTPA. Our method brings novel contributions along three orthogonal axes: (1) automatic detection of anatomical structures; (2) anatomical aware pretraining, and (3) a dual-hop deep neural net for PE detection. We obtain state-of-the-art results on the publicly available multicenter large-scale RSNA dataset.

A rare and late complication of lung cancer: bronchial rupture

Abstract Background Tracheobronchial injuries generally occur due to iatrogenic or traumatic causes. Although bronchial rupture due to teratoma and germ cell tumors has been reported in the literature, no cases related to lung cancer have been determined. Our case is presented because of the refusal to be examined for the mass in the lung and the detection of bronchial rupture afterward when he presented with massive hemoptysis. Case presentation A 65-year-old male patient was admitted to the emergency department with the complaint of massive hemoptysis. Six months ago, bronchoscopy was recommended due to the 8 × 7 cm cavitary lesion obliterating the bronchus in the anterior upper lobe of the right lung on chest computed tomography, but the patient refused. The sputum sample, requested 3 times, was negative for acid-resistant bacteria, and no growth was detected in the mycobacterial culture. In the new pulmonary CT angiography, a progressive cavitary lesion invading the right main bronchus, carina, and vena cava superior was observed. Following tranexamic acid treatment and bronchial artery embolization, hemoptysis significantly decreased in the follow-up. In the flexible bronchoscopy performed for diagnostic purposes, the carina was pushed to the left and invaded, and there was damage to the right main bronchus. A biopsy was not performed due to the risk of bleeding, and lavage was performed. Lavage was negative for ARB, there was no growth in the mycobacteria culture, and cytology did not reveal malignant cells. The patient, diagnosed with right main bronchial rupture, was considered inoperable and died 1 month later due to respiratory failure. Conclusions Examinations should be initiated as soon as malignancy is suspected. When diagnosis and treatment are delayed, complications that would be challenging to intervene may develop.

Implementation, Clinical Benefit and Safety of a D-Dimer-Focused Pulmonary Embolism Testing Pathway in the Emergency Department

Computed tomography pulmonary angiogram (CTPA) is overused during pulmonary embolism (PE) testing in the emergency department (ED), whereas prediction rules and D-dimer are underused. We report the adherence, clinical benefit, and safety of a D-dimer-only strategy to guide need for PE imaging in the ED. This was a prospective multicenter implementation study in 2 EDs with historical and external controls. Patients with suspected PE underwent D-dimer testing and imaging (CTPA or ventilation-perfusion scan) when D-dimer levels were 500 ng/mL or more. PE was ruled out if D-dimer was less than 500 ng/mL or with negative imaging. The primary implementation outcome was the proportion of patients tested for PE in adherence with the pathway. The primary clinical benefit outcome was the proportion of patients tested for PE who received pulmonary imaging. The primary safety outcome was diagnosis of PE in the 30 days following negative PE testing postimplementation. Between January 2018 and June 2021, 16,155 patients were tested for PE, including 33.4% postimplementation, 30.7% preimplementation, and 35.9% in an external control site. Adherence with the D-dimer-only pathway was 97.6% (adjusted odds ratio (aOR) post- versus preimplementation 5.26 (95% confidence interval 1.70 to 16.26). There was no effect on the proportion undergoing PE imaging. Imaging yield increased aOR 4.89 (1.17 to 20.53). Two cases of PE (0.04%; 0.01% to 0.16%) were diagnosed within 30 days. In this Canadian ED study, the uptake of a D-dimer-only PE testing strategy was high. Implementation was associated with higher imaging yield and a D-dimer level of less than 500 ng/mL safely excluded PE.

Comparison of the accuracy of four diagnostic prediction rules for pulmonary embolism in patients admitted to the emergency department

Introduction and ObjectivesRuling out pulmonary embolism (PE) through a combination of clinical assessment and D-dimer level can potentially avoid excessive use of computed tomography pulmonary angiography (CTPA). We aimed to compare the diagnostic accuracy of the standard approach based on the Wells and Geneva scores combined with a standard D-dimer cut-off (500 ng/ml), with three alternative strategies (age-adjusted and the YEARS and PEGeD algorithms) in patients admitted to the emergency department (ED) with suspected PE. MethodsConsecutive outpatients admitted to the ED who underwent CTPA due to suspected PE were retrospectively assessed. Sensitivity, specificity, positive and negative predictive values, likelihood ratios and diagnostic odds ratios were calculated and compared between the different diagnostic prediction rules. ResultsWe included 1402 patients (mean age 69±18 years, 54% female), and PE was confirmed in 25%. Compared to the standard approach (p<0.001), an age-adjusted strategy increased specificity with a non-significant decrease in sensitivity only in patients older than 70 years. Compared to the standard and age-adjusted approaches, the YEARS and PEGeD algorithms had the highest specificity across all ages, but were associated with a significant decrease in sensitivity (p<0.001), particularly in patients aged under 60 years (sensitivity of 81% in patients aged between 51 and 60 years). ConclusionCompared to the standard approach, all algorithms were associated with increased specificity. The age-adjusted strategy was the only one not associated with a significant decrease in sensitivity compared to the standard approach, enabling CTPA requests to be reduced safely.

Pulmonary Embolism: An Update Based on the Revised AWMF-S2k Guideline.

Pulmonary embolism (PE) is the third most common acute cardiovascular disease. The risk of PE increases with age and mortality is high. Patients are stratified into hemodynamically stable versus unstable patients, as this has important implications for diagnosis and therapy. Since clinical signs and symptoms of acute PE are nonspecific, the clinical likelihood of PE is estimated to guide diagnostic pathways. D-dimer testing is performed in hemodynamically stable patients with low or intermediate probability of PE and the visualization of thromboembolism and its sequelae is commonly achieved with computed tomography pulmonary angiography (CTPA), supplemented by ultrasound techniques. With confirmed PE, another risk stratification estimates disease severity and defines intensity and setting of the ensuing treatment. The therapeutic spectrum ranges from outpatient treatment with initial oral anticoagulation to thrombolytic or interventional treatment in the intensive care unit or catheterization laboratory. In single cases, even acute surgical thrombectomy is attempted.

The Relationship Between Pulmonary Artery Diameter Measured by Chest CT and D-Dimer in COVID-19 Patients Admitted to the Emergency Department

Aim: The coronavirus disease 2019 (COVID-19) pandemic has become a global health emergency due to its rapid spread worldwide. Our study evaluated the relationship between pulmonary artery diameter and d-dimer in COVID-19 patients. &#x0D; &#x0D; Material and Methods: Patients aged 18 years and older with International Classification of Diseases 10 diagnosis code U07.3 who were admitted to our emergency department between March 15, 2020, and November 31, 2020, were included in our study. Demographic data (age, sex), laboratory tests (polymerase chain reaction test, d-dimer level), and imaging results (chest computed tomography, computed tomography pulmonary angiography) of the patients were retrospectively analyzed using medical records and the hospital electronic record system. &#x0D; &#x0D; Results: A total of 1654 patients were included in the study. The 30-day mortality rate was 13.7% (n=227). The most effective independent variable on 30-day mortality was 44 years of age or older. Pulmonary artery diameter and d-dimer levels were found to be higher in both the group with typical COVID-19 chest computed tomography findings and in patients who died within 30 days. However, unlike the literature, there was no significant difference in pulmonary artery diameter and d-dimer levels between patients with and without pulmonary embolism. &#x0D; &#x0D; Conclusion: In conclusion, we found a weak positive correlation between d-dimer and pulmonary artery diameter in COVID-19 patients.

PE-Ynet: a novel attention-based multi-task model for pulmonary embolism detection using CT pulmonary angiography (CTPA) scan images.

Pulmonary Embolism (PE) has diverse manifestations with different etiologies such as venous thromboembolism, septic embolism, and paradoxical embolism. In this study, a novel attention-based multi-task model is proposed for PE segmentation and detection from Computed Tomography Pulmonary Angiography (CTPA) images. A Y-Net architecture is used to implement this model, which facilitates segmentation and classification jointly, improving performance and efficiency. It is leveraged with Multi Head Attention (MHA), which allows the model to focus on important regions of the image while suppressing irrelevant information, improving the accuracy of the segmentation and detection tasks. The proposed PE-YNet model is tested with two public datasets, achieving a maximum mean detection and segmentation accuracy of 99.89% and 99.83%, respectively, on the CAD-PE challenge dataset. Similarly, it also achieves a detection accuracy of 99.75% and a segmentation accuracy of 99.81% on the FUMPE dataset. Additionally, sensitivity analysis also shows a high sensitivity of 0.9885 for the localization error ɛ = 0 for the CAD-PE dataset, demonstrating the model's robustness against false predictions compared to state-of-the-art models. Further, this model also exhibits lower inference time, size, and memory usage compared to representative models. An automated PE-YNet tool can assist physicians with PE diagnosis, treatment, and prognosis monitoring in the clinical management of CoVID-19.

Utilizing Point-Of-Care Ultrasound (POCUS) for Diagnosis in a Resource-Limited Setting: A Case Report of Pulmonary Embolism

Introduction: Acute pulmonary embolism (PE) is a common cause of cardiovascular-related deaths and poses diagnostic challenges due to its variable and non-specific symptoms. Computed tomography pulmonary angiography (CTPA) is the gold standard imaging method for PE diagnosis, but its availability is limited in resource-constrained settings. Point-of-care ultrasound (POCUS) has emerged as a valuable tool for emergency physicians, aiding accurate diagnoses, procedural guidance, and resuscitation efforts. Case Presentation: This case report presents a 76-year-old woman with non-specific symptoms diagnosed with PE using POCUS in the Emergency Department of the Korle Bu Teaching Hospital. The POCUS findings included an enlarged right ventricle with a flattened septum (D sign), poor cardiac contractility, thrombi in the right ventricle and a plethoric Inferior Vena Cava (IVC). Prompt diagnosis facilitated timely management, leading to improved patient outcomes. Conclusion: POCUS has proven to be indispensable in resource-constrained settings where confirmatory diagnostics are limited. Incorporating POCUS training into emergency medicine residency programs and establishing emergency ultrasound fellowships in under-resourced regions like Africa can enhance its utilization and empower clinicians in such environments. Equipping emergency room clinicians with POCUS skills enables timely diagnosis, early interventions, shorter Emergency Department stays, and improved patient outcomes. This approach can contribute to building an African faculty proficient in emergency ultrasound, facilitating the education and training of more clinicians in POCUS, and ultimately enhancing healthcare outcomes in resource-limited environments.

Oscillometry Longitudinal Data on COVID-19 Acute Respiratory Syndrome Treated with Non-Invasive Respiratory Support.

Background: Oscillometry allows for the non-invasive measurements of lung mechanics. In COVID-19 ARDS patients treated with Non-Invasive Oxygen Support (NI-OS), we aimed to (1) observe lung mechanics at the patients' admission and their subsequent changes, (2) compare lung mechanics with clinical and imaging data, and (3) evaluate whether lung mechanics helps to predict clinical outcomes. Methods: We retrospectively analyzed the data from 37 consecutive patients with moderate-severe COVID-19 ARDS. Oscillometry was performed on their 1st, 4th, and 7th day of hospitalization. Resistance (R5), reactance (X5), within-breath reactance changes (ΔX5), and the frequency dependence of the resistance (R5-R19) were considered. Twenty-seven patients underwent computed tomographic pulmonary angiography (CTPA): collapsed, poorly aerated, and normally inflated areas were quantified. Adverse outcomes were defined as intubation or death. Results: Thirty-two patients were included in this study. At the first measurement, only 44% of them had an abnormal R5 or X5. In total, 23 patients had measurements performed on their 3rd day and 7 on their 7th day of hospitalization. In general, their R5, R5-R19, and ΔX decreased with time, while their X5 increased. Collapsed areas on the CTPA correlated with the X5 z-score (ρ = -0.38; p = 0.046), while poorly aerated areas did not. Seven patients had adverse outcomes but did not present different oscillometry parameters on their 1st day of hospitalization. Conclusions: Our study confirms the feasibility of oscillometry in critically ill patients with COVID-19 pneumonia undergoing NI-OS. The X5 z-scores indicates collapsed but not poorly aerated lung areas in COVID-19 pneumonia. Our data, which show a severe impairment of gas exchange despite normal reactance in most patients with COVID-19 ARDS, support the hypothesis of a composite COVID-19 ARDS physiopathology.

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.

Pulmonary embolism response teams. A description of the first 36-month Australian experience.

High/intermediate-risk pulmonary embolism (PE) confers increased risk of cardiovascular morbidity and mortality. International guidelines recommend the formation of a PE response team (PERT) for PE management because of the complexity of risk stratification and emerging treatment options. However, there are currently no available Australian data regarding outcomes of PE managed through a PERT. To analyse the clinical and outcome data of patients from an Australian centre with high/intermediate-risk PE requiring PERT-guided management. We performed a retrospective observational study of 75 consecutive patients with high/intermediate-risk PE who had PERT involvement, between August 2018 and July 2021. We recorded clinical and interventional data at the time of PERT and assessed patient outcomes up to 30 days from PERT initiation. We used unpaired t tests to compare right to left ventricular (RV/LV) ratios by computed tomography criteria or transthoracic echocardiogram (TTE) at baseline and after interventions. Data were available for 74 patients. Initial computed tomography pulmonary angiography RV/LV ratio was increased at 1.65 ± 0.5 and decreased to 1.30 ± 0.29 following PERT-guided interventions (P < 0.001). TTE RV/LV ratio also decreased following PERT-guided management (1.09 ± 0.19 vs 0.93 ± 0.17; P < 0.001). 20% of patients had any bleeding complication, but two-thirds were mild, not requiring intervention. All-cause mortality was 6.8%, and all occurred within the first 7 days of admission. The PERT model is feasible in a large Australian centre in managing complex and time-critical PE. Our data demonstrate outcomes comparable with existing published international PERT data. However, successful implementation at other Australian institutions may require adequate centre-specific resource availability and the presence of multispeciality input.

Quality of referrals for lower extremity ultrasonography and computed tomography pulmonary angiography and associations with positive findings of venous thromboembolism

IntroductionThe referral is the basis for radiologists’ assessment of modality, protocol and urgency, and insufficient information may threaten patient safety. The aim of this study was to assess the completeness of referrals for lower extremity venous duplex ultrasonography (LEVDUS) and computed tomography pulmonary angiography (CTPA), and to investigate associations between the provided clinical information including risk factors, symptoms and lab results in the referrals and positive findings of deep vein thrombosis (DVT) and pulmonary embolism (PE), respectively. MethodsReferrals for LEVDUS (801) and CTPA (800) performed from 2016 to 2019 were obtained. Three categories of clinical information from the referrals were recorded: symptoms, risk factors and laboratory results, as well as positive imaging findings of venous thromboembolism (VTE). Referral completeness was rated from zero to three according to how many categories of clinical information the referral provided. ResultsInformation from all three clinical information categories was provided in 15% and 25% of referrals for LEVDUS and CTPA, respectively, while 2% and 10% of referrals did not contain any clinical information. Symptoms were provided most often (85% for LEVDUS and 94% for CTPA). Provided information about risk factors was significantly associated with positive findings for LEVDUS, (p = 0.02) and CTPA (p < 0.001). ConclusionA great majority of referrals failed to provide one or more categories of clinical information. Risk factors were associated with a positive finding of VTE on LEVDUS and CTPA. Implications for practiceImproving clinical information in referrals may improve justification, patient safety and quality of radiology services.

Subsegmental Pulmonary Embolism Post Cesarean Section: A Case Report

Diagnosing pulmonary embolism during pregnancy and the postpartum period can indeed be challenging due to overlapping symptoms with normal pregnancy changes. It's important for healthcare providers to maintain a high index of suspicion and use appropriate diagnostic tools, such as imaging studies like CT pulmonary angiography or ventilation-perfusion scans, while considering the maternal and fetal risks involved in the diagnostic process. We report a case of postpartum subsegmental pulmonary embolism.

The Assessment of Pleural Effusion Using CT Pulmonary Angiography-A Review

Background: Pleural effusion is a common clinical presentation with various etiologies, including pulmonary embolism (PE), which remains underdiagnosed. The association between PE and pleural effusion, particularly the exudative type, necessitates a thorough understanding of the diagnostic role of computed tomography pulmonary angiography (CTPA). Objective: This review aims to elucidate the prevalence and characteristics of pleural effusions in PE patients and to evaluate the effectiveness of CTPA in the diagnosis of unilateral pleural effusions of unknown etiology. Methods: A systematic search across databases such as Google Scholar, PubMed, and NCBI yielded 39 articles, from which 20 met the inclusion criteria focused on the diagnostic utility of CTPA for unilateral pleural effusion. Studies were appraised for relevance to PE and pleural effusion, methodological rigor, and contribution to the field. Results: The review revealed that pleural effusions associated with PE typically present modestly and peak around the third day post-embolism. Persistent or late-onset effusions may suggest recurrent embolism or other pathologies. Contrast-enhanced CT demonstrated variable sensitivity and specificity in detecting malignant pleural effusions, suggesting the need for cautious interpretation and possible further invasive investigation. Conclusion: CTPA plays a critical role in the evaluation of pleural effusion, especially when PE is suspected. An integrated diagnostic approach, including pleural-phase thoracic CT, is recommended for patients with suspected malignant pleural effusions to improve clinical outcomes.

Predictive accuracy of years score in diagnosis of pulmonary embolism

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

Intraoperative Cardiac Arrest During Liposuction: A Case Report.

With the popularity of liposuction surgery, more awareness should be obtained regarding complications. Liposuction has been thought of as a safe procedure with a very low incidence of major complications. However, life-threatening risks of liposuction have rarely been reported. We present a case of a 36-year-old woman who developed cardiac arrest during a liposuction procedure, and we present a literature review. She was previously healthy and had no risk factors for pulmonary embolism. The diagnosis was made based on clinical presentation and the presence of an electrolyte disorder and a positive sign on computed tomography pulmonary angiogram (CTPA). Mild hypothermia treatment, symptomatic treatment, and supportive therapy were applied. As the respiratory and circulation were smooth, she was discharged to a rehabilitation hospital. Seven months after discharge, the patient was still in a coma with eye opening. Spinal anesthesia, pulmonary embolism, and hyperkalemia are the most probable contributors to the cardiac arrest observed during the liposuction procedure in this specific case. There is a heightened imperative to vigilantly monitor for critical incidents during these operations and to meticulously identify associated risk factors during liposuction.

Development and Validation of a Natural Language Processing Model to Identify Low-Risk Pulmonary Embolism in Real Time to Facilitate Safe Outpatient Management

ObjectiveThis study aimed to (1) develop and validate a natural language processing (NLP) model to identify presence of PE based on real-time radiology reports and (2) identify low-risk PE patients based on previously validated risk stratification scores using variables extracted from the electronic health record (EHR) at the time of diagnosis. The combination of these approaches yielded an NLP-based clinical decision support tool that can identify patients presenting to the emergency department (ED) with low-risk PE as candidates for outpatient management. Research QuestionCan an NLP-based clinical decision support tool that uses real-time radiology reports and EHR data accurately identify patients presenting to the ED with low-risk PE? Study Designs and MethodsData were curated from all patients who received a PE-protocol computed tomography pulmonary angiogram (CTPA) imaging study in the ED of a three-hospital academic health system between June 1, 2018 and December 31, 2020 (n = 12,183). The “preliminary” radiology reports from these imaging studies made available to ED providers at the time of diagnosis were adjudicated as positive or negative for PE by the clinical team. The reports were then divided into development, internal validation, and temporal validation cohorts in order to train, test, and validate an NLP model that could identify presence of PE based on unstructured text. For risk stratification, patient and encounter-level data elements were curated from the EHR and used to compute a real-time simplified pulmonary embolism severity (sPESI) score at the time of diagnosis. Chart abstraction was performed on all low-risk PE patients admitted for inpatient management. ResultsWhen applied to the internal validation and temporal validation cohorts, the NLP model identified presence of PE from radiology reports with an AUROC of 0.99, sensitivity 0.86-0.87, and specificity 0.99. Across cohorts, 10.5% of PE-CTPA studies were positive for PE, of which 22.2% were classified as low-risk by sPESI score. Of all low-risk PE patients, 74.3% were admitted for inpatient management. InterpretationThis study demonstrates that an NLP-based model utilizing real-time radiology reports can accurately identify patients with PE. Further, this model, used in combination with a validated risk stratification score (sPESI), provides a clinical decision support tool that accurately identifies patients in the ED with low-risk PE as candidates for outpatient management.

The CT revolution: the role of PIOPED II in establishing CT pulmonary angiography as the reference standard for pulmonary embolism diagnosis.

The PIOPED II study provided a robust estimate of the diagnostic accuracy of multidetector CTPA in suspected pulmonary embolism and played a pivotal role in establishing CTPA as the current diagnostic gold standard https://bit.ly/3HEyVxy.