Triple rule-out computed tomographic angiography for chest pain: a diagnostic systematic review and meta-analysis

Initial Triage and Management of Patients with Acute Aortic Syndromes

The acute aortic syndromes (AAS) are life-threatening vascular compromises within the aortic wall. These include aortic dissection (AD), intramural hematoma (IMH), penetrating aortic ulcer (PAU), and blunt traumatic thoracic aortic injury (BTTAI). While patients classically present with chest pain, the presentation may be highly variable. Timely diagnosis is critical to initiate definitive treatment and maximize chances of survival. In high-risk patients, treatment should begin immediately, even while diagnostic evaluation proceeds. The mainstay of medical therapy is acute reduction of heart rate and blood pressure. Surgical intervention is often required but is informed by patient anatomy and extent of vascular compromise.

Management and outcomes with 5-year mortality of patients with mildly elevated high-sensitivity troponin T levels not meeting criteria for myocardial infarction

OBJECTIVES

To examine management and outcomes of patients presenting to EDs with symptoms suggestive of acute coronary syndrome, who have mild non-dynamically elevated high-sensitivity troponin T (HsTnT) levels, not meeting the fourth universal definition of myocardial infarction (MI) criteria (observation group).

METHODS

Consecutive patients presenting to the ED with symptoms suggestive of acute coronary syndrome at Liverpool Hospital, Sydney, Australia, those having ≥2 HsTnT levels after initial assessment were adjudicated according to the fourth universal definition of MI, as MI ruled-in, MI ruled-out, or myocardial injury in whom MI is neither ruled-in nor ruled-out (>1 level ≥15 ng/L, called observation group); follow-up was 5 years.

RESULTS

Of 2738 patients, 547 were in the observation group, of whom 62% were admitted to hospital, 52% to cardiac services, whereas 97% of MI ruled-in patients and 21% of MI ruled-out patients were admitted; P < 0.001. Non-invasive testing occurred in 42% of observation group patients (36% had echo-cardiography), and 16% had coronary angiography. Of observation group patients, MI rates were 1.5% during hospitalisation and 4% during the following year, similar to that in those with MI ruled-in, among those with MI ruled-out, the MI rate was 0.2%. The 1-year death rate was 13% among observation group patients and 11% MI ruled-in patients (P = 0.624), whereas at 5 years among observation group patients, type 1 MI and type 2 MI were 48%, 26% and 58%, respectively (P = 0.001).

CONCLUSION

Very few unselected consecutive patients attending ED, with minor stable HsTnT elevation, had MI, although most had chronic myocardial injury. Late mortality rates among observation group patients were higher than those with confirmed type 1 MI but lower than those with type 2 MI.

The Role of Triple Rule-out CT in an Indian Emergency Setting

Background

Emergency physicians are acutely aware of the consequences of missing fatal diagnoses for acute non-traumatic chest pain and subjecting patients to over-testing. In the large arsenal of tests that are available to us, a triple rule-out computed tomography (TRO-CT) Angiography is often less pursued, due to concerns about their efficacy and safety or because of nescience. We aim to find the yield of the test in an Indian emergency setting and impart some knowledge about it along the way.

Materials and methods

Twenty-six patients who presented to the emergency department of our institute with acute chest pain, with non-specific electrocardiogram (ECG) findings and negative serial troponin I, underwent TRO-CT. HEART scores of all patients, calculated at their presentation, were correlated with TRO-CT findings.

Results

Triple rule-out computed tomography angiography was positive in 5 patients (20%), of which 4 cases (16%) were diagnosed to have significant coronary artery disease and one had an acute pulmonary embolism. All 4 patients who had significant coronary artery disease (CAD) diagnosed by TRO-CT had a HEART score of intermediate risk. The mean effective radiation dose of the entire TRO study was 19.024 ± 3.319 mSv (range = 13.89-25.95 mSv).

Conclusion

Triple rule-out CT angiography is a useful tool in the evaluation of patients presenting with acute chest pain in the emergency and can be an important adjunct in ruling out significant CAD in intermediate-risk patients. Emergency physicians and young residents need to know about this tool in their armamentarium to tackle doubtful cases.

How to cite this article

Pattereth N, Chaliyadan S, Mathew R, Kumar S, Das CJ, Aggarwal P. et al. The Role of Triple Rule-out CT in an Indian Emergency Setting. Indian J Crit Care Med 2023;27(3):190-194.

2022 use of coronary computed tomographic angiography for patients presenting with acute chest pain to the emergency department: An expert consensus document of the Society of cardiovascular computed tomography (SCCT): Endorsed by the American College of Radiology (ACR) and North American Society for cardiovascular Imaging (NASCI)

Coronary computed tomography angiography (CTA) improves the quality of care for patients presenting with acute chest pain (ACP) to the emergency department (ED), particularly in patients with low to intermediate likelihood of acute coronary syndrome (ACS). The Society of Cardiovascular Computed Tomography Guidelines Committee was formed to develop recommendations for acquiring, interpreting, and reporting of coronary CTA to ensure appropriate, safe, and efficient use of this modality. Because of the increasing use of coronary CTA testing for the evaluation of ACP patients, the Committee has been charged with the development of the present document to assist physicians and technologists. These recommendations were produced as an educational tool for practitioners evaluating acute chest pain patients in the ED, in the interest of developing systematic standards of practice for coronary CTA based on the best available data or broad expert consensus. Due to the highly variable nature of medical care, approaches to patient selection, preparation, protocol selection, interpretation or reporting that differs from these guidelines may represent an appropriate variation based on a legitimate assessment of an individual patient's needs.

Comparison of Triple-Rule-Out Prospectively ECG-triggered Systolic and Diastolic Acquisition Protocol in Patients With Acute Chest Pain

PURPOSE

The purpose of this study was to compare image quality and coronary interpretability of triple-rule-out systolic and diastolic protocols in patients with acute chest pain.

MATERIALS AND METHODS

From March 2016 to October 2017 the authors prospectively enrolled patients with undifferentiated acute chest pain, who were at low to intermediate cardiovascular risk. Those with heart rate >75 bpm underwent a systolic prospectively triggered acquisition (systolic triggering [ST]), and in those with ≤75 bpm, end-diastolic triggering (DT) was instead performed. Examinations were evaluated for coronary artery disease, aortic dissection, and pulmonary embolism. Image quality was assessed using a Likert scale. Coronary arteries interpretability was evaluated both on a per-vessel and a per segment basis. The occurrence of major adverse cardiovascular events was investigated.

RESULTS

The final study population was 189 patients. Fifty-two patients (27.5%) underwent systolic acquisition and 137 (72.5%) underwent diastolic acquisition. No significant differences in overall image quality were observed between DT and ST groups (median score 5 [interquartile ranges 4 to 5] vs. 4 [interquartile ranges 4 to 5], P =0.074). Although both DT and ST protocols showed low percentages of noninterpretable coronary arteries on a per-vessel (1.5% and 6.7%, respectively) and per-segment analysis (1% and 4.7%, respectively), these percentages resulted significantly higher for ST groups ( P <0.001). Obstructive coronary stenosis was observed in 18 patients. Only one case of pulmonary embolism was diagnosed and no cases of aortic dissection were found in our population. No death or major adverse cardiovascular events were observed during follow-up among the 2 groups.

CONCLUSIONS

Results showed that triple-rule-out computed tomography angiography is a reliable technique in patients with acute chest pain and that an ST acquisition protocol could be considered an alternative acquisition protocol in patients with higher heart rate, reaching a good image quality.

The triple rule out CT in acute chest pain: a challenge for emergency radiologists?

PURPOSE

To evaluate the feasibility of triple rule out computed tomography (TRO-CT) in an emergency radiology workflow by comparing the diagnostic performance of cardiovascular and general radiologists in the interpretation of emergency TRO-CT studies in patients with acute and atypical chest pain.

METHODS

Between July 2017 and December 2019, 350 adult patients underwent TRO-CT studies for the assessment of atypical chest pain. Three radiologists with different fields and years of expertise (a cardioradiologist-CR, an emergency senior radiologist-SER, and an emergency junior radiologist-JER) retrospectively and independently reviewed all TRO-CT studies, by trans-axial and multiplanar reconstruction only. Concordance rates were then calculated using as reference blinded results from a different senior cardioradiologist, who previously evaluated studies using all available analysis software.

RESULTS

Concordance rate was 100% for acute aortic syndrome (AAS) and pulmonary embolism (PE). About coronary stenosis (CS) for non-obstructive (<50%), CS concordance rates were 97.98%, 90.91%, and 97.18%, respectively, for CR, SER, and JER; for obstructive CS (>50%), concordance rates were respectively 88%, 85.7%, and 71.43%. Moreover, it was globally observed a better performance in the evaluation of last half of examinations compared with the first one.

CONCLUSIONS

Our study confirm the feasibility of the TRO-CT even in an Emergency Radiology department that cannot rely on a 24/7 availability of a dedicated skilled cardiovascular radiologist. The "undedicated" radiologists could exclude with good diagnostic accuracy the presence of obstructive stenosis, those with a clinical impact on patient management, without needing time-consuming software and/or reconstructions.

Radiological, histopathological findings, and clinical outcome of pulmonary artery sarcoma

Pulmonary artery sarcoma is a rare malignancy with poor prognosis. Lack of specific clinical manifestations, some patients are even confirmed postoperatively or at autopsy, that leads to the delay in treatment. Early diagnosis and radical surgical resection provide the possibility of prolonged survival. We retrospectively enrolled 13 patients diagnosed with pulmonary artery sarcoma at our hospital between 2015 and 2019. Their clinical, laboratory, radiological, and histopathological data were collected and analyzed. Published case series were also reviewed. Results show that, the median age of the patients was 53 years, with 6 (46.2%) males. The most common symptom is exertional dyspnea. Erythrocyte sedimentation rate and C-reactive protein were increased in 76.9% and 69.2% of these patients, while D-Dimer remained normal or elevated slightly. Metastasis was present at diagnosis in eight (61.5%) patients. Ten patients were diagnosed histologically: three were diagnosed after pulmonary endarterectomy, four by endobronchial ultrasound-guided transbronchial needle aspiration, two by percutaneous lung biopsy, and one by endovascular aspiration biopsy. Four patients underwent surgery and one is waiting for surgery. Nine patients received chemotherapy; and three of them received targeted therapy with anlotinib after chemotherapy. Two patients received anti-PD-1 monoclonal antibody. One patient died during endobronchial ultrasound-guided transbronchial needle aspiration. Two patients died 9 and 13 months after diagnosis, respectively; one refused invasive diagnostic procedures and died three months after clinical diagnosis. In conclusion, the most appropriate approach to get tissue specimen needs to be tailored to every pulmonary artery sarcoma patient. Pulmonary endarterectomy combined with chemotherapy and targeted therapy has prolonged their survival time.

Improving Contrast Enhancement in Pulmonary CTA: The value of breathing maneuvers

Purpose

To investigate contrast dynamics and artifacts associated with different breathing maneuvers during pulmonary computed tomography angiography (pCTA) in a prospective randomized clinical trial.

Method

Three different breathing maneuvers (inspiration, expiration, Mueller) were randomly assigned to 146 patients receiving pCTA for suspected pulmonary embolism (PE). Contrast enhancement of central and peripheral arteries and imaging quality of lung parenchyma were compared and analyzed. Results were compared by using the analysis of variances (ANOVA) and Kruskal-Wallis-Test.

Results

Mean enhancement in the pulmonary trunk was highest during breath-hold in inspiration (293 HU, range 195-460 HU) compared to Mueller (259 HU, range 136-429 HU, p = 0022) and expiration (267 HU, range 115-376 HU). This was similar for the right pulmonary artery (inspiration 289 HU, range 173-454 HU; Mueller 250 HU, range 119-378 HU; p = 0.007; expiration 257 HU, range 114-366 HU; p = 0.032) and left pulmonary artery (inspiration 280.3 HU, range 170-462 HU; Mueller 245 HU, range 111-371 HU; p = 0.016; expiration 252 HU, range 110-371 HU).Delineation of peripheral arteries was significantly better in inspiration vs Mueller (p = 0.006) and expiration (p = 0.049). Assessment of the lung parenchyma was significantly better in inspiration vs Mueller (p = 0.013) or expiration (p < 0.001).

Conclusions

Resting inspiratory position achieved the highest enhancement levels in central and peripheral pulmonary arteries and best image quality of the pulmonary parenchyma in comparison to other breathing maneuvers. It is necessary to train the maneuver prior to the examination in order to avoid deep inspiration with the risk of suboptimal opacification of the pulmonary arteries.

Coronary computed tomography angiography (CCTA): effect of bolus-tracking ROI positioning on image quality

Objectives

The aim of the study was to evaluate the effect of bolus-tracking ROI positioning on coronary computed tomography angiography (CCTA) image quality.

Methods

In this retrospective monocentric study, all patients had undergone CCTA by step-and-shoot mode to rule out coronary artery disease within a cohort at intermediate risk. Two groups were formed, depending on ROI positioning (left atrium (LA) or ascending aorta (AA)). Each group contained 96 patients. To select pairs of patients, propensity score matching was used. Image quality with regard to coronary arteries as well as pulmonary arteries was evaluated using quantitative and qualitative scores.

Results

In terms of the coronary arteries, there was no significant difference between both groups using quantitative (SNR AA 14.92 vs. 15.46; p = 0.619 | SNR LM 19.80 vs. 20.30; p = 0.661 | SNR RCA 24.34 vs. 24.30; p = 0.767) or qualitative scores (4.25 vs. 4.29; p = 0.672), respectively. With regard to pulmonary arteries, we found significantly higher quantitative (SNR RPA 8.70 vs. 5.89; p < 0.001 | SNR LPA 9.06 vs. 6.25; p < 0.001) and qualitative scores (3.97 vs. 2.24; p < 0.001) for ROI positioning in the LA than for ROI positioning in the AA.

Conclusions

ROI positioning in the LA or the AA results in comparable image quality of CT coronary arteriography, while positioning in the LA leads to significantly higher image quality of the pulmonary arteries. These results support ROI positioning in the LA, which also facilitates triple-rule-out CT scanning.

Key Points

• ROI positioning in the left atrium or the ascending aorta leads to comparable image quality of the coronary arteries.

• ROI positioning in the left atrium results in significantly higher image quality of the pulmonary arteries.

• ROI positioning in the left atrium is feasible to perform triple-rule-out CTA.

Machine learning-based CT fractional flow reserve assessment in acute chest pain: first experience

Background

Computed tomography (CT)-derived fractional flow reserve (FFR_CT) enables the non-invasive functional assessment of coronary artery stenosis. We evaluated the feasibility and potential clinical role of FFR_CT in patients presenting to the emergency department with acute chest pain who underwent chest-pain CT (CPCT).

Methods

For this retrospective IRB-approved study, we included 56 patients (median age: 62 years, 14 females) with acute chest pain who underwent CPCT and who had at least a mild (≥25% diameter) coronary artery stenosis. CPCT was evaluated for the presence of acute plaque rupture and vulnerable plaque features. FFR_CT measurements were performed using a machine learning-based software. We assessed the agreement between the results from FFR_CT and patient outcome (including results from invasive catheter angiography and from any non-invasive cardiac imaging test, final clinical diagnosis and revascularization) for a follow-up of 3 months.

Results

FFR_CT was technically feasible in 38/56 patients (68%). Eleven of the 38 patients (29%) showed acute plaque rupture in CPCT; all of them underwent immediate coronary revascularization. Of the remaining 27 patients (71%), 16 patients showed vulnerable plaque features (59%), of whom 11 (69%) were diagnosed with acute coronary syndrome (ACS) and 10 (63%) underwent coronary revascularization. In patients with vulnerable plaque features in CPCT, FFRCT had an agreement with outcome in 12/16 patients (75%). In patients without vulnerable plaque features (n=11), one patient showed myocardial ischemia (9%). In these patients, FFR_CT and patient outcome showed an agreement in 10/11 patients (91%).

Conclusions

Our preliminary data show that FFR_CT is feasible in patients with acute chest pain who undergo CPCT provided that image quality is sufficient. FFR_CT has the potential to improve patient triage by reducing further downstream testing but appears of limited value in patients with CT signs of acute plaque rupture.

Computed Tomographic Angiography for Risk Stratification in Patients with Acute Chest Pain - The Triple Rule-out Concept in the Emergency Department

BACKGROUND

Acute chest pain is one of the most common reasons for Emergency Department (ED) visits and hospital admissions. As this could represent the first symptom of a lifethreatening condition, urgent identification of the etiology of chest pain is of utmost importance in emergency settings. Such high-risk conditions that can present with acute chest pain in the ED include Acute Coronary Syndromes (ACS), Pulmonary Embolisms (PE) and Acute Aortic Syndromes (AAS).

DISCUSSION

The concept of Triple Rule-out Computed Tomographic Angiography (TRO-CTA) for patients presenting with acute chest pain in the ED is based on the use of coronary computed tomographic angiography as a single imaging technique, able to diagnose or exclude three lifethreatening conditions in one single step: ACS, AAS and PE. TRO-CTA protocols have been proved to be efficient in the ED for diagnosis or exclusion of life-threatening conditions and for differentiation between various etiologies of chest pain, and application of the TRO-CTA protocol in the ED for acute chest pain of uncertain etiology has been shown to improve the further clinical evaluation and outcomes of these patients.

CONCLUSION

This review aims to summarize the main indications and techniques used in TRO protocols in EDs, and the role of TRO-CTA protocols in risk stratification of patients with acute chest pain.

Pulmonary intimal sarcoma involving the pulmonary valve and right ventricular outflow tract: A case report and literature review

INTRODUCTION

Pulmonary artery intimal sarcoma (PAIS) is a rare and highly aggressive tumor, and approximately 80% of pulmonary cases occur in the pulmonary trunk. We report herein a case of retrograde extension of the sarcoma to the pulmonary valve and right ventricle, which is an uncommon manifestation of this lethal tumor.

PATIENT CONCERNS

A 41-year-old woman was initially diagnosed with pulmonary thromboembolism (PTE) and transferred to our hospital.

DIAGNOSIS

Computed tomographic pulmonary angiography (CTPA) showed that there are low-density filling defects in both pulmonary arteries, and the patient was diagnosed with PTE. However, the ultrasonographers considered that the lesion is a space-occupying type that involves the right ventricular outflow tract and pulmonary valve instead of PTE. Postoperative pathology confirmed the diagnosis of PAIS.

INTERVENTIONS

The patient underwent resection of pulmonary artery sarcoma and endarterectomy.

OUTCOMES

During the follow-up via telephone 1 month after discharge, the patient reported to have been feeling well.

CONCLUSION

Owing to the rarity of the disease and its non-specific clinical manifestations, approximately half of the PAIS cases are misdiagnosed or have a delayed diagnosis. Thus, improving our understanding of the disease and facilitating its early diagnosis are essential.

Clinical and radiological features of pulmonary artery sarcoma: A report of nine cases

OBJECTIVE

To improve our understanding and facilitate early diagnosis of pulmonary artery sarcoma (PAS).

PATIENTS AND METHODS

The clinical and radiological features of 9 histopathologically confirmed patients with PAS were retrospectively analyzed.

RESULTS

Our PAS cohort consisted of 5 males and 4 females, with insidious presentation, the main symptoms were dyspnea (88.9%), syncope (33.3%), palpitations (22.2%), chest pain (22.2%), hemoptysis (11.1%) and constitutional symptoms, including fever (44.4%), fatigue (55.6%) and weight loss (55.6%). Elevated serum inflammatory markers, including an elevated erythrocyte sedimentation rate, lactate dehydrogenase and C-reactive protein, were recorded in 9 (100%), 7 (77.8%) and 8 (88.9%) patients, respectively. Computed tomography pulmonary angiography (CTPA) indicated that 8 (88.9%) patients had intraluminal defects, appearing as rounded, bulging or lobulated masses that display uneven signal intensification in contract-enhanced scans in the pulmonary arteries (PAs). Three (33.3%) of the patients had metastases outside of the PA. Before surgery, 7 patients had been misdiagnosed as pulmonary thromboembolic diseases (PTD), 2 as others, with mean misdiagnosis duration of 7.2 ± 7.1 months. All patients had received thrombolytic and/or anticoagulation therapy and their diseases progressed until receiving pulmonary endarterectomy.

CONCLUSIONS

The clinical features of PAS that may help to differentiate it from PTD are its insidious onset, constitutional symptoms, increased serum inflammatory marker levels, lack of predisposing factors and unresponsiveness to thrombolytic and/or anticoagulation therapy. Typical CTPA features are crucial for suspicion of PAS. Early biopsy or surgery should be performed to confirm the diagnosis of PAS and improve its prognosis.

National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand: Australian clinical guidelines for the management of acute coronary syndromes 2016

INTRODUCTION

The modern care of suspected and confirmed acute coronary syndrome (ACS) is informed by an extensive and evolving evidence base. This clinical practice guideline focuses on key components of management associated with improved clinical outcomes for patients with chest pain or ACS. These are presented as recommendations that have been graded on both the strength of evidence and the likely absolute benefit versus harm. Additional considerations influencing the delivery of specific therapies and management strategies are presented as practice points.

MAIN RECOMMENDATIONS

This guideline provides advice on the standardised assessment and management of patients with suspected ACS, including the implementation of clinical assessment pathways and subsequent functional and anatomical testing. It provides guidance on the: diagnosis and risk stratification of ACS; provision of acute reperfusion therapy and immediate post-fibrinolysis care for patients with ST segment elevation myocardial infarction; risk stratification informing the use of routine versus selective invasive management for patients with non-ST segment elevation ACS; administration of antithrombotic therapies in the acute setting and considerations affecting their long term use; and implementation of an individualised secondary prevention plan that includes both pharmacotherapies and cardiac rehabilitation. Changes in management as a result of the guideline: This guideline has been designed to facilitate the systematic integration of the recommendations into a standardised approach to ACS care, while also allowing for contextual adaptation of the recommendations in response to the individual's needs and preferences. The provision of ACS care should be subject to continuous monitoring, feedback and improvement of quality and patient outcomes.

Clinical update. Computed Tomography — an Emerging Tool for Triple Rule-Out in the Emergency Department. A Review

New imaging tools have been developed in recent years to rapidly and accurately diagnose life-threatening diseases associated with high mortality rates, such as acute coronary syndromes, acute aortic dissection, or pulmonary embolism. The concept of using computed tomographic (CT) assessment in emergency settings is based on the possibility of excluding multiple acute pathologies within one scan. It can be used for patients complaining of acute chest pain of unclear etiology with the possible association of acute coronary dissection or pulmonary embolism, but only a low to moderate risk of developing an acute coronary syndrome. One of the benefits of this protocol is the possibility of decreasing the number of patients who are hospitalized for further investigations. The technique also allows the rapid triage of patients and the safe discharge of those who show negative results. The aim of this review is to summarize the current medical literature regarding the potential use of CT for the triple rule-out (TRO) of coronary etiologies.

ANMCO-SIMEU Consensus Document: in-hospital management of patients presenting with chest pain

Chest pain is a common general practice presentation that requires careful diagnostic assessment because of its diverse and potentially serious causes. However, the evaluation of acute chest pain remains challenging, despite many new insights over the past two decades. The percentage of patients presenting to the emergency departments because of acute chest pain appears to be increasing. Nowadays, there are two essential chest pain-related issues: (i) the missed diagnoses of acute coronary syndromes with a poor short-term prognosis; and (ii) the increasing percentage of hospitalizations of low-risk cases. It is well known that hospitalization of a low-risk chest pain patient can lead to unnecessary tests and procedures, with an increasing trend of complications and burden of costs. Therefore, the significantly reduced financial resources of healthcare systems induce physicians and administrators to improve the efficiency of care protocols for patients with acute chest pain. Despite the efforts of the Scientific Societies in producing statements on this topic, in Italy there is still a significant difference between emergency physicians and cardiologists in managing patients with chest pain. For this reason, the aim of the present consensus document is double: first, to review the evidence-based efficacy and utility of various diagnostic tools, and, second, to delineate the critical pathways (describing key steps) that need to be implemented in order to standardize the management of chest pain patients, making a correct diagnosis and treatment as uniform as possible across the entire country.

Lex parsimoniae

We present a noteworthy case of dual pathology in a 62-year-old female with recurrent chest pains and extensive cardiac risk factors. From computed tomography coronary angiography, a left anterior descending artery lesion was identified and successfully revascularized with a drug-eluting stent. Due to persistent chest pain, further investigation revealed a descending aortic dissection, which was conservatively managed. This case highlights the potential challenges of diagnosis in dual pathologies and emphasizes initiating appropriate investigations. <Learning objectives: It is important to consider all differential diagnoses in atypical presentations of possible acute coronary syndrome. As clinical presentations and risk factors may be similar, initiating appropriate diagnostic and management pathways are crucial to avoid misdiagnosis.>.

Imaging of nontraumatic thoracic emergencies

PURPOSE OF REVIEW

Acute chest symptoms form an important incentive for imaging in the emergency setting. This review discusses the radiologic features of various vascular and pulmonary diseases leading to acute respiratory distress and recent developments on important emergency radiologic examinations.

RECENT FINDINGS

Recently, triple-rule-out computed tomography protocol was introduced in diagnosis of chest pain, and advancing computed tomography technology and knowledge have led to discussion on treatment of pulmonary embolism. Diffuse pulmonary opacities remain a diagnostic dilemma in the emergency setting and although imaging findings can often be nonspecific, they help in guiding toward accurate diagnosis and timely management.

SUMMARY

Though promising, triple-rule-out is not yet justified because of low incidence of additional findings compared with conventional computed tomography angiography in chest pain, but it might be suited for clinical practice in the near future. Relevance of isolated subsegmental pulmonary embolism is unknown and research on this topic is needed and on its way. We provided some key findings in differentiating diffuse pulmonary opacities and describe the additional value of chest ultrasound in this clinical dilemma. A brief sidestep to pneumothorax is made, as this is also a frequent finding in the acute dyspneic patient, as well as in patients with acute chest pain.

Imaging the posterior mediastinum: a multimodality approach

The posterior mediastinum contains several structures that can produce a wide variety of pathologic conditions. Descending thoracic aorta, esophagus, azygos and hemiazygos veins, thoracic duct, lymph nodes, adipose tissue, and nerves are all located in this anatomical region and can produce diverse abnormalities. Although chest radiography may detect many of these pathologic conditions, computed tomography and magnetic resonance are the imaging modalities of choice for further defining the relationship of posterior mediastinal lesions to neighboring structures and showing specific imaging features that narrow the differential diagnosis. This review emphasizes modality-related answers to morphologic questions, which provide precise diagnostic information.

Chest Pain of Uncertain Aetiology: Role of Contrast Enhanced Computed Tomography in the Emergency Department

There is increasing role of computed tomographic (CT) in the assessment of acute chest pain in the emergency department especially when the diagnosis is not clear. We report a case where non ECG gated contrast enhanced CT in the emergency department for rule-out of pulmonary embolus guided to the actual diagnosis, which was, acute coronary event, as evidenced by the presence of perfusion defect.

The Effectiveness of Non-ECG-Gated Contrast-Enhanced Computed Tomography for the Diagnosis of Non-ST Segment Elevation Acute Coronary Syndrome

Non-ST segment elevation acute coronary syndrome (NSTE-ACS) can be difficult to diagnose accurately, especially in the hyper-acute phase. Non-ECG-gated contrast-enhanced computed tomography (non-ECG-gated CE-CT) has been used in many institutions for screening acute chest pain. Although early defects (EDs) observed in non-ECG-gated CE-CT have been reported as a sign of acute myocardial ischemia, the precise diagnostic value of this sign for acute coronary syndrome has not been fully elucidated. We investigated the usefulness of non-ECG-gated CE-CT for the diagnosis of NSTE-ACS. We retrospectively reviewed 556 patients who were hospitalized for acute-onset chest pain and who underwent emergent coronary angiography. Non-ECG-gated CE-CT was performed in 23 of these patients. Two readers independently analyzed CT images using a 5-point scale. Of the 23 patients, 13 were diagnosed with NSTE-ACS. The remaining 10 patients were diagnosed with other conditions. The sensitivity, specificity, positive predictive value, and negative predictive value, respectively, of EDs on non-ECG-gated CE-CT to detect NSTE-ACS were 84.6%, 90%, 91.7%, and 81.8%. The identification of EDs was consistent between the two readers. Non-ECG-gated CE-CT may be useful not only to triage patients with chest pain by ruling out other conditions, but also to accurately diagnose NSTE-ACS.

Acute chest pain in the high-sensitivity cardiac troponin era: A changing role for noninvasive imaging?

Management of patients with acute chest pain remains challenging. Cardiac biomarker testing reduces the likelihood of erroneously discharging patients with acute myocardial infarction (AMI). Despite normal contemporary troponins, physicians have still been reluctant to discharge patients without additional testing. Nowadays, the extremely high negative predictive value of current high-sensitivity cardiac troponin (hs-cTn) assays challenges this need. However, the decreased specificity of hs-cTn assays to diagnose AMI poses a new problem as noncoronary diseases (eg, pulmonary embolism, myocarditis, cardiomyopathies, hypertension, renal failure, etc) may also cause elevated hs-cTn levels. Subjecting patients with noncoronary diseases to unnecessary pharmacological therapy or invasive procedures must be prevented. Attempts to improve the positive predictive value to diagnose AMI by defining higher initial cutoff values or dynamic changes over time inherently lower the sensitivity of troponin assays. In this review, we anticipate a potential changing role of noninvasive imaging from ruling out myocardial disease when troponin values are normal toward characterizing myocardial disease when hs-cTn values are (mildly) abnormal.

Diagnostic Yield of Triple-Rule-Out CT in an Emergency Setting

OBJECTIVE

The objective of the present study is to quantify the diagnostic yield of triple-rule-out (TRO) CT for the evaluation of acute chest pain in emergency department patients.

MATERIALS AND METHODS

All TRO CT studies performed at our institution from 2006 to 2015 were reviewed. Scans were performed on a 256-MDCT scanner, with the use of ECG gating and a biphasic contrast injection. Radiology reports were reviewed to identify diagnoses that could explain chest pain, including coronary and noncoronary diagnoses, and significant incidental findings that did not account for the patient's presentation. The total numbers of coronary and noncoronary diagnoses and incidental findings were calculated.

RESULTS

Four of 1196 total cases that were identified were excluded from the study because of inadequate image quality. A total of 970 patients (81.4%) had a negative study result without a significant coronary or noncoronary diagnosis. A total of 139 patients (11.7%) had significant coronary artery disease (50% stenosis or greater). One hundred six patients (8.9%) had a noncoronary diagnosis that could explain chest pain (p < 0.02), most commonly pulmonary embolism (28 patients [2.3%]), aortic aneurysm (24 patients [2.0%]), or pneumonia (20 patients [1.7%]). Thirty cases (27.3%) of pulmonary embolism and aortic pathologic findings would not have been detected with coronary CT angiography because of unopacified right-side circulation or limited z-axis coverage. A total of 528 incidental findings not considered to explain chest pain were noted in 418 patients (35.1%).

CONCLUSION

In 8.9% of patients, TRO CT detected a significant noncoronary diagnosis that could explain acute chest pain, including pathologic findings that would not be identified on dedicated coronary CT angiography.

Chest pain: coronary CT in the ER

Cardiac CT has developed into a robust clinical tool during the past 15 years. Of the fields in which the potential of cardiac CT has raised more interest is chest pain in acute settings. In fact, the possibility to exclude with high reliability obstructive coronary artery disease (CAD) in patients at low-to-intermediate risk is of great interest both from the clinical standpoint and from the management standpoint. Several other modalities, with or without imaging, have been used during the past decades in the settings of new onset chest pain or in acute chest pain for both diagnostic and prognostic assessment of CAD. Each one has advantages and disadvantages. Most imaging modalities also focus on inducible ischaemia to guide referral to invasive coronary angiography. The advent of cardiac CT has introduced a new practice diagnostic paradigm, being the most accurate non-invasive method for identification and exclusion of CAD. Furthermore, the detection of subclinical CAD and plaque imaging offer the opportunity to improve risk stratification. Moreover, recent advances of the latest generation CT scanners allow combining both anatomical and functional imaging by stress myocardial perfusion. The role of cardiac CT in acute settings is already important and will become progressively more important in the coming years.

Triple Rule Out versus CT Angiogram Plus Stress Test for Evaluation of Chest Pain in the Emergency Department

Introduction

Undifferentiated chest pain in the emergency department (ED) is a diagnostic challenge. One approach includes a dedicated chest computed tomography (CT) for pulmonary embolism or dissection followed by a cardiac stress test (TRAD). An alternative strategy is a coronary CT angiogram with concurrent chest CT (Triple Rule Out, TRO). The objective of this study was to describe the ED patient course and short-term safety for these evaluation methods.

Methods

This was a retrospective observational study of adult patients presenting to a large, community ED for acute chest pain who had non-diagnostic electrocardiograms (ECGs) and normal biomarkers. We collected demographics, ED length of stay, hospital costs, and estimated radiation exposures. We evaluated 30-day return visits for major adverse cardiac events.

Results

A total of 829 patients underwent TRAD, and 642 patients had TRO. Patients undergoing TRO tended to be younger (mean 52.3 vs 56.5 years) and were more likely to be male (42.4% vs. 30.4%). TRO patients tended to have a shorter ED length of stay (mean 14.45 vs. 21.86 hours), to incur less cost (median $449.83 vs. $1147.70), and to be exposed to less radiation (median 7.18 vs. 16.6mSv). No patient in either group had a related 30-day revisit.

Conclusion

Use of TRO is feasible for assessment of chest pain in the ED. Both TRAD and TRO safely evaluated patients. Prospective studies investigating this diagnostic strategy are needed to further assess this approach to ED chest pain evaluation.

Research priorities for the influence of gender on diagnostic imaging choices in the emergency department setting

Diagnostic imaging is a cornerstone of patient evaluation in the acute care setting, but little effort has been devoted to understanding the appropriate influence of sex and gender on imaging choices. This article provides background on this issue and a description of the working group and consensus findings reached during the diagnostic imaging breakout session at the 2014 Academic Emergency Medicine consensus conference "Gender-specific Research in Emergency Care: Investigate, Understand, and Translate How Gender Affects Patient Outcomes." Our goal was to determine research priorities for how sex and gender may (or should) affect imaging choices in the acute care setting. Prior to the conference, the working group identified five areas for discussion regarding the research agenda in sex- and gender-based imaging using literature review and expert consensus. The nominal group technique was used to identify areas for discussion for common presenting complaints to the emergency department where ionizing radiation is often used for diagnosis: suspected pulmonary embolism, suspected kidney stone, lower abdominal pain with a concern for appendicitis, and chest pain concerning for coronary artery disease. The role of sex- and gender-based shared decision-making in diagnostic imaging decisions is also raised.