Accuracy of M-mode and two-dimensional echocardiography in the diagnosis of aortic dissection: an experience with 128 cases

Diagnostic Accuracy of Transthoracic Echocardiography for Acute Type A Aortic Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Transthoracic echocardiography (TTE) is currently recognized as the potential first-line imaging test for patients with suspected acute type A aortic syndrome (AAAS). Direct TTE sign for detecting AAAS is positive if there is an intimal flap separating two aortic lumens or aortic wall thickening seen in the ascending aorta. Indirect TTE sign indicates high-risk features of AAAS, such as aortic root dilatation, pericardial effusion, and aortic regurgitation. Our aim is to summarize the existing clinical evidence regarding the diagnostic accuracy of TTE and to evaluate its potential role in the management of patients with suspected AAAS.

METHODS

We included prospective or retrospective diagnostic cohort studies, written in any language, that specifically focused on using TTE to diagnose AAAS from databases such as PubMed, EMBASE, MEDLINE, and the Cochrane Library. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio [1], and hierarchical summary receiver-operating characteristic (HSROC) curve were calculated for TTE in diagnosing AAAS. We applied Quality Assessment of Diagnostic Accuracy (QUADAS-2) tool and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) quality assessment criteria.

RESULTS

Ten studies (2886 patients) were included in the meta-analysis. The pooled sensitivity and specificity of direct TTE signs were 58% (95% CI, 38-76%) and 94% (95% CI, 89-97%). For any TTE signs, the pooled sensitivity and specificity were 91% (95% CI, 85-94%) and 74% (95% CI, 61-84%). The diagnostic accuracy of direct TTE signs was significantly higher than that of any TTE signs, as measured by the area under the HSROC curve [0.95 (95% CI, 0.92-0.96) vs. 0.87 (95% CI, 0.84-0.90)] in four studies.

CONCLUSIONS

Our study suggests that TTE could serve as the initial imaging test for patients with suspected AAAS. Given its high specificity, the presence of direct TTE signs may indicate AAAS, whereas the absence of any TTE signs, combined with low clinical suspicion, could suggest a lower likelihood of AAAS.

Type A aortic dissection mimicking saddle pulmonary embolism on CT imaging

Type A aortic dissection is an uncommon cause of chest pain that carries a high morbidity and mortality rate. A previous history of hypertension and coronary artery bypass grating (CABG) are recognized risk factors for Type A aortic dissection. We present a case of an elderly man who presents with acute onset chest pain and was found to have an acute ruptured Type A aortic dissection that has a "saddle pulmonary embolism"-like appearance on computed tomography (CT) imaging. We also describe the clinical, laboratory, and radiological workup done leading up to the diagnosis of Type A aortic dissection in the emergency setting.

Early Screening for Aortic Dissection With Point-of-Care Ultrasound by Emergency Physicians: A Prospective Pilot Study

OBJECTIVES

To investigate the effect of point-of-care ultrasound (POCUS) use by emergency physician (EPs) on the diagnosis, treatment, and safety of POCUS in patients with aortic dissection (AD) in emergency settings.

METHODS

Patients presenting to the emergency department of West China Hospital of Sichuan University with suspected AD from July 1, 2016, to December 31, 2016 were divided into a control group and an ultrasound (US) group. The control group was evaluated by routine procedures for triage, diagnosis, and treatment. In addition, an EP POCUS examination was performed in the US group. The patients in the US group were furtherly divided into subgroup A and subgroup B according to the Stanford type of AD. The sensitivity and specificity of EP POCUS compared to computed tomographic angiography (CTA) were compared. The door-to-CTA examination time, door-to-diagnosis time, door-to-targeted treatment time, and outcome were compared between the groups.

RESULTS

A total of 127 patients were enrolled: 72 in the US group and 55 in the control group. In the US group, compared with CTA, the sensitivity of EP POCUS was 86.4%, and the specificity was 100.0%. The door-to-diagnosis times were 10.5 minutes in the US group and 79.0 minutes in the control group (P < .05). The door-to-CTA examination time and the door-to-targeted-treatment time had no differences between the US and control groups (P > .05). The in-hospital mortality and mortality within 3 months after discharge were 4.2% and 25.0% in the US group and 9.1% and 20.8% in the control group (P > .05).

CONCLUSIONS

Compared with CTA, EP POCUS in patients suspected of having AD is highly sensitive and specific and has shown no adverse effect on the treatment start-up time, in-hospital mortality, and mortality within 3 months after discharge.

Iatrogenic Aortic Dissection Presenting With Leg Pain Diagnosed With Point-of-care Ultrasound

Iatrogenic aortic dissection (IAD) status-post-cardiac catheterization is a rare complication often isolated to the proximal aorta. This is a case of IAD isolated to the distal aorta in a 41-year-old female who presented to the emergency department with right leg pain after undergoing three cardiac catheterizations. The diagnosis of IAD was made upon discovery of an intimal flap in the distal aorta and femoral artery while performing a point-of-care ultrasound to evaluate for deep vein thrombosis.

Detection of Type B Aortic Dissection in the Emergency Department with Point-of-Care Ultrasound

Aortic dissection (AD) is a rare, time-sensitive, and potentially fatal condition that can present with subtle signs requiring timely diagnosis and intervention. Although definitive diagnosis is most accurately made through computed tomography angiography, this can be a time-consuming study and the patient may be unstable, thus preventing the study’s completion. Chest radiography (CXR) signs of AD are classically taught yet have poor diagnostic reliability. Point-of-care ultrasound (POCUS) is increasingly used by emergency physicians for the rapid diagnosis of emergent conditions, with multiple case reports illustrating the sonographic signs of AD. We present a case of Stanford type B AD diagnosed by POCUS in the emergency department in a patient with vague symptoms, normal CXR, and without aorta dilation. A subsequent review of CXR versus sonographic signs of AD is described.

Ultrasonographic detection of chronic type A aortic dissection extending to the right extracranial internal carotid artery: A case report

We report the case of a patient with chronic type A aortic dissection (AD), who had been admitted, 18 months ago, to another hospital with acute chest-tearing pain accompanied with transient loss of consciousness. His symptoms resolved but he reported after discharge a toothache and fluctuating right mandibular pain. He presented to our outpatient clinic because his facial pain aggravated. Physical examination demonstrated a bruit over the right carotid artery. Transthoracic echocardiography and carotid sonography demonstrated aortic dissection extending into the extracranial right internal carotid artery (ICA), which was tortuous. The patient refused surgery. This case reminds us that AD can involve the extracranial ICA, and that long-term survival is possible with type A acute AD without treatment. Carotid ultrasonography is noninvasive, inexpensive, easily performed, and can lead to the detection of chronic type A AD extending to the extracranial ICA.

Ortner’s syndrome: Focused cardiac ultrasound and rapid ultrasound in shock examination at emergency department unfold the life-threatening cause for a cardiovocal condition

Introduction:

Ortner’s syndrome is a rare condition, known as cardiovocal condition as patients present with hoarseness of voice due to cardiovascular causes.

Case presentation:

We present a case of Ortner’s syndrome secondary to leaking thoracic aortic aneurysm in a patient who came to emergency department with hypotension and hoarseness of voice for 3 months. Focused cardiac ultrasound (FOCUS) and rapid ultrasound in shock (RUSH) were performed which revealed a thoracic aortic arch aneurysm.

Discussion:

Focused cardiac ultrasound and rapid ultrasound in shock examination in the emergency department had expedited the diagnosis of this rare condition, hence the subsequent definitive investigation and management.

Conclusion:

This case highlights the need for high index of suspicion for thoracic aneurysm in patients with unexplained cardiovocal symptoms. It also highlights the importance of point-of-care ultrasound in the emergency department and the significance of utilizing the suprasternal view to look for pathology at the arch of aorta.

Point-of-care Ultrasound Diagnosis of an Atypical Acute Aortic Dissection

Aortic dissections have a vast array of clinical presentations that rarely follow traditional teachings. Dissections are rapidly fatal conditions requiring immediate diagnosis and treatment to reduce morbidity and mortality. We present a case of an acute aortic dissection presenting as abrupt onset, atraumatic leg pain with absent distal extremity pulses. The prompt use of point-of-care ultrasound detected an intimal flap within the abdominal aorta allowing immediate surgical consultation and intervention.

Echocardiographic Applications of M-Mode Ultrasonography in Anesthesiology and Critical Care

Proficiency in echocardiography and lung ultrasound has become essential for anesthesiologists and critical care physicians. Nonetheless, comprehensive echocardiography measurements often are time-consuming and technically challenging, and conventional 2-dimensional images do not permit evaluation of specific conditions (eg, systolic anterior motion of the mitral valve, pneumothorax), which have important clinical implications in the perioperative setting. M-mode (motion-based) ultrasonographic imaging, however, provides the most reliable temporal resolution in ultrasonography. Hence, M-mode can provide clinically relevant information in echocardiography and lung ultrasound-driven approaches for diagnosis, monitoring, and interventional procedures performed by anesthesiologists and intensivists. Although M-mode is feasible, this imaging modality progressively has been abandoned in echocardiography and is often underutilized in lung ultrasound. This article aims to comprehensively illustrate contemporary applications of M-mode ultrasonography in the anesthesia and critical care medicine practice. Information presented for each clinical application will include image acquisition and interpretation, evidence-based clinical implications in the critically ill and surgical patient, and limitations. The present article focuses on echocardiography and reviews left ventricular function (mitral annular plane systolic excursion, E-point septal separation, fractional shortening, and transmitral propagation velocity); right ventricular function (tricuspid annular plane systolic excursion, subcostal echocardiographic assessment of tricuspid annulus kick, outflow tract fractional shortening, ventricular septal motion, wall thickness, and outflow tract obstruction); volume status and responsiveness (inferior vena cava and superior vena cava diameter and respiratory variability [collapsibility and distensibility indexes]); cardiac tamponade; systolic anterior motion of the mitral valve; and aortic dissection.

Diagnostic performance of emergency transthoracic focus cardiac ultrasound in suspected acute type A aortic dissection

Type A aortic dissection (AD) is a deadly disease. Rapid identification of patients requiring immediate advanced aortic imaging or transfer to specialized centers is needed to improve outcomes. We evaluated the diagnostic performance of transthoracic focus cardiac ultrasound (FOCUS) performed by emergency physicians, alone and in combination with the aortic dissection detection (ADD) risk score in suspected type A AD. This was a prospective study performed on patients with suspected type A AD. FOCUS evaluated the presence of intimal flap/intramural hematoma (direct signs of AD), ascending aorta dilatation, aortic valve insufficiency or pericardial effusion/tamponade (indirect signs of AD). The ADD risk score of each patient was calculated according to guidelines. The final diagnosis was established after review of complete clinical data. 50 (18%) patients of 281 had a final diagnosis of type A AD. Detection of any FOCUS sign (direct or indirect) of AD had a sensitivity of 88% (95% CI 76-95%) for the diagnosis of type A AD. Presence of ADD risk score > 0 or detection of any FOCUS sign increased diagnostic sensitivity to 96% (95% CI 86-99%). Detection of direct FOCUS signs had a specificity of 94% (95% CI 90-97%), while combination of ADD risk score > 1 with detection of direct FOCUS signs had a specificity of 98% (95% CI 96-99%). FOCUS demonstrated acceptable accuracy as a triage tool to rapidly identify patients with suspected type A AD needing advanced aortic imaging or transfer, but it cannot be used as a stand-alone test even if combined with ADD risk score classification.

When does a D-dimer test help make the diagnosis of aortic dissection?

We present a case of an 84-year-old woman who presented with vague abdominal discomfort and syncope secondary to a type A acute aortic dissection. In pursuit of the diagnosis, multiple tests were ordered after the history and physical exam were complete. When the D-dimer levels were reported to be high, a bedside transthoracic ultrasound was performed which showed dilated aortic root and pericardial tamponade, leading us to order a computerized tomography to confirm the diagnosis of acute aortic dissection. A diagnostic testing algorithm being used in our institution using D-dimer, ultrasound, and other tests are provided in patients presenting with possible acute aortic dissection. In this case, bedside ultrasound helped us to rapidly make the diagnosis of acute aortic dissection and arrange for further inpatient care.

Point-of-care focused cardiac ultrasound for the assessment of thoracic aortic dimensions, dilation, and aneurysmal disease

OBJECTIVES

  Thoracic aortic aneurysm and thoracic aortic dissection are related and potentially deadly diseases that present with nonspecific symptoms. Transthoracic echocardiography (TTE) may detect thoracic aortic pathology and is being increasingly performed by the emergency physician at the bedside; however, the accuracy of point-of-care (POC) focused cardiac ultrasound (FOCUS) for thoracic aortic aneurysm and thoracic aortic dissection has not been studied. The objective of this pilot study was to explore the agreement, sensitivity, and specificity of FOCUS for thoracic aortic dimensions, dilation, and aneurysm compared with CT angiography (CTA) as the reference standard.

METHODS

  This study was a retrospective pilot analysis of image and chart data on consecutive patients presenting to an urban, academic emergency department (ED) between January 2008 and June 2010, who had both a FOCUS and a CTA for suspicion of thoracic aorta pathology. Thoracic aorta dimensions were measured from recordings by three ultrasound-trained emergency physicians blinded to any initial FOCUS and CTA results. CTA measurements were obtained by a radiologist blinded to the FOCUS results. Using cutoffs of 40 and 45 mm, we calculated the sensitivity and specificity of FOCUS for aortic dilation and aneurysm with the largest measurement on CT as the reference standard. Bland-Altman plots with 95% limits of agreement were used to demonstrate agreement for aortic measurements, kappa statistics to assess the degree of agreement between tests for aortic dilation, and intraclass correlation for interobserver and intraobserver variability.

RESULTS

  Ninety-two patients underwent both FOCUS and CTA during the study period. Ten FOCUS studies had inadequate visualization for all measurements areas. Eighty-two patients were included in the final analysis. Mean (±SD) age was 58.1 (±16.6) years and 58.5% were male. Sensitivity, specificity, and the observed kappa value (95% confidence interval [CI]) between FOCUS and CTA for the presence of aortic dilation at the 40-mm cutoff were 0.77 (95% CI = 0.58 to 0.98), 0.95 (95% CI = 0.84 to 0.99), and 0.74 (95% CI = 0.58 to 0.90), respectively. The mean difference (95% limits of agreement) for the Bland-Altman plots was 0.6 mm (-5.3 to 6.5) for the sinuses of Valsalva, 4 mm (-2.7 to 10.7) for the sinotubular junction, 1.5 mm (-5.8 to 8.8) for the ascending aorta, and 2.2 mm (-5.9 to 10.3) for the descending aorta.

CONCLUSIONS

  In this retrospective pilot study, FOCUS demonstrated good agreement with CTA measurements of maximal thoracic aortic diameter. FOCUS appears to be specific for aortic dilation and aneurysm when compared to CTA, but requires further prospective study.

The role of transthoracic echocardiography in the diagnosis and management of acute type A aortic syndrome

BACKGROUND

Transthoracic echocardiography (TTE) has been traditionally considered inadequate for the diagnosis of acute type A aortic syndrome (AAAS). In the last decade, high-resolution probes and harmonic imaging have been implemented in new echocardiographic systems. However, studies assessing the diagnostic accuracy of TTE for the identification of AAAS in large populations using modern ultrasound technology are lacking.

METHODS

The diagnostic value of harmonic imaging TTE was assessed in 270 consecutive patients with suspected AAAS in whom TTE was the initial diagnostic test.

RESULTS

Acute type A aortic syndrome was diagnosed in 67 patients and excluded in 203 patients (disease prevalence 25%). Sixty-two patients had a classic acute type A aortic dissection, and 5, an acute type A intramural hematoma. Image quality achieved was considered optimal in 244 patients (90%). In the whole study population, TTE had sensitivity, specificity, positive predictive value, and negative predictive value for the diagnosis of AAAS of 87%, 91%, 75%, and 95%, respectively. When evaluating only patients with optimal image quality, these values increased to 97%, 100%, 100%, and 99%, respectively. Forty-seven patients with clear-cut evidence of AAAS were transferred immediately to the operative room, where transesophageal echocardiography confirmed the diagnosis obtained by TTE in all patients.

CONCLUSIONS

Transthoracic echocardiography is a useful imaging modality for the diagnosis of classic acute type A aortic dissection. It cannot be used as the sole screening technique for detecting AAAS, but in the light of the predictive values observed, patients with optimal image quality and clear-cut diagnosis of AAAS should proceed to the operative room, whereas in patients with negative or indeterminate studies, other imaging techniques are needed to refine the diagnosis.

Para-aortic arch abscess secondary to Staphylococcus aureus pneumonia

Staphylococcus aureus is a relatively common pathogen causing pneumonia in the community, hospital ward and intensive care unit. Although pneumonia is responsible for significant morbidity and mortality, especially in elderly and immunocompromised patients, it is usually uncomplicated and resolves without complications. The case of a woman who developed a para-aortic abscess after a community-acquired S aureus pneumonia infection is presented. A number of diagnostic imaging modalities were used to reach the diagnosis. This complication has not been reported previously and it is likely secondary to suppurative lymphadenitis of a station 5 or 6 node. The patient was successfully managed nonsurgically with computed tomography-guided drainage and intravenous antibiotics.

Ultrasound diagnosis of type a aortic dissection

BACKGROUND

An aortic dissection is a life-threatening process that must be diagnosed and treated expeditiously. Imaging modalities used for diagnosis in the emergency department include computed tomography, magnetic resonance imaging, and trans-esophageal echocardiography. There are significant limitations to these studies, including patient contraindications (intravenous contrast dye allergies, renal insufficiency, metal-containing implants, hemodynamic instability) and the length of time required for study completion and interpretation by a radiologist or cardiologist.

OBJECTIVES

A case is presented that demonstrates how emergency physicians can use trans-thoracic and abdominal bedside ultrasound to diagnose a type A aortic dissection.

CASE REPORT

A 72-year-old woman presented with chest pain radiating to her neck and back that was concerning for aortic dissection. This was subsequently confirmed and further classified as a type A dissection by bedside emergency physician-performed ultrasound. The images showed a clear intimal flap in the abdominal aorta, a dilatated aortic root, and extension of the intimal flap into the left common carotid artery. With prompt diagnosis, the patient was able to have emergent surgical consultation, confirmatory imaging, and intervention before further complication occurred.

CONCLUSION

This case provides an example of how emergency trans-thoracic and abdominal ultrasound can be used to promptly diagnose a type A aortic dissection and expedite further consultation and prompt management.

The diagnosis of aortic dissection by emergency medicine ultrasound

A series of five cases of aortic dissection are presented that were diagnosed by emergency physicians using ultrasound to search the abdominal and thoracic aorta for pathology. Aortic dissection is a vascular emergency with a high morbidity and mortality, yet its presentation can be varied and subtle. This article reports the use of Emergency ultrasound in a series of five aortic dissections discovered with a limited, yet timely viewing of the aorta and heart by emergency physicians.

Dissection of the proximal thoracic aorta: a new ultrasonographic sign in the subxiphoid view

Dissection of the thoracic aorta is a life-threatening event that presents with some regularity to emergency departments (EDs). Despite often nonspecific symptoms, it is critical to catch this disease process early, especially when the proximal aorta is involved because dissections involving the aortic root can lead to myocardial infarction and failure of the aortic valve resulting in death. Current imaging options include contrast-enhanced chest computed tomography (CT), angiography, magnetic resonance imaging, or transesophageal echocardiography. Although not as accurate as transesophageal echocardiography, transthoracic echocardiography (TTE) can be used to detect aortic dissection as well. We present a previously undescribed echocardiographic finding associated with proximal dissection of the thoracic aorta in 7 cases.

Aorta: comprehensive evaluation by echocardiography and transesophageal echocardiography

The emergence of transesophageal echocardiography has made echocardiography a nearly ideal technique for evaluating the thoracic aorta. The echocardiographic anatomy of the aorta is reviewed. The role of echocardiography for evaluating aortic dissection, thoracic aortic aneurysm, aortic atherosclerosis, and thoracic aortic trauma is discussed. Comparison of echocardiography with other techniques for imaging the aorta (computed tomographic scan, nuclear magnetic resonance, and aortography) is presented.

Effect of medical and surgical therapy on aortic dissection evaluated by transesophageal echocardiography. Implications for prognosis and therapy. The European Cooperative Study Group on Echocardiography

BACKGROUND

Aortic dissection still has a poor prognosis despite progress in therapy. Therefore, this prospective follow-up study was designed to determine whether the degree of communication between true and false lumen in relation to the type of dissection, analyzed by transesophageal echocardiography, influences the risk after initiation of medical or surgical therapy.

METHODS AND RESULTS

In eight centers, 168 patients (124 men and 44 women) of age range of 23-84 years with proven aortic dissection were examined by transesophageal echocardiography in the acute phase, after start of medical and/or surgical therapy, and during follow-up (0-65 months; mean, 10 months). Analyses were performed prospectively according to a detailed study protocol. Patients were subdivided by transesophageal echocardiography according to a modified DeBakey classification. Type I aortic dissection was found in 35%, type II aortic dissection in 17%, and type III aortic dissection in 48%. Preoperative mortality was 3%, 7%, and 2%, and survival rates were 52%, 69%, and 70%, respectively. Type III aortic dissection could be subdivided into those with communication and antegrade dissection (ca) (50%), with communication and retrograde dissection limited to the descending aorta (cr desc) (10%), with dissection extended to the aortic arch and ascending aorta (cr asc) (27%), and with noncommunicating (nc) aortic dissection (13%). An open false lumen with no thrombus formation was present in types I, II, III ca and III cr asc aortic dissection in 17%, 21%, 39%, and 27% respectively, although it was most pronounced in types III nc and III cr desc (75% and 78%). During follow-up in patients who survived, thrombus was demonstrated in the false lumen in 80% of type I aortic dissection and 81% of types III ca and III cr asc. Open false lumen was seen in type II aortic dissection in 18%. Spontaneous healing was found in 4% with type II and 4% with type III aortic dissection (mainly in patients with type III nc aortic dissection). Patients with fluid extravasation, pleural effusion, pericardial tamponade, and periaortic effusion as well as mediastinal hematoma had a mortality of 52%. Reoperations were necessary in 12-29%, with the highest rate in patients with type III ca aortic dissection. Survival for patients with types III nc and III cr desc aortic dissection was higher than those with types I, II, III ca, and III cr asc.

CONCLUSIONS

Preoperative mortality appears to be reduced by transesophageal echocardiography, allowing rapid initiation of treatment. Intraoperative and postoperative mortality in aortic dissection remains high. Risk factors are fluid extravasation and an open false lumen with high communication. Thrombus formation in the false lumen can be regarded as a good prognostic sign. Surgery appears to be only a first step in the treatment of aortic dissection. Second surgery or closure of entry sites based on intraoperative echocardiography may be considered to induce thrombus formation and reduce aortic wall stress.

Value of transesophageal echocardiography combined with computed tomography for assessing repaired type A aortic dissection

Thirty-two patients with repaired type A aortic dissection were examined by transthoracic echocardiography (TTE) (n = 32), transesophageal echocardiography (TEE) (n = 30), computed tomography (CT) (n = 29), or a combination of all 3, to assess course and complications as a function of the surgical procedure. The mean follow-up period was 55.7 months (range 3 to 132). Surgery consisted of a replacement of the ascending aorta in 25 patients (group 1) with extension to the transverse aorta in 7 (group 2). The transverse diameter of the aorta, the persistence of the false lumen, thrombus formation and flow dynamics in the false lumen were evaluated by TEE. Ten patients (31%) had a dilation in the initial ascending aorta (sinus of Valsalva aneurysm in 6 patients, and a false aneurysm in the other 4). Three of 4 patients with a proximal pseudoaneurysm underwent operation after TEE and CT evaluation. In the descending thoracic aorta, there was good agreement between TEE and CT scan determinations of transverse vessel diameter. Persistence of flow within the false lumen was significantly more frequent in patients with a dilated aorta (p < 0.05), whereas thrombosis was seen more often and false lumen less often in patients with nondilated aorta. No significant differences in vessel status or outcome were observed between the 2 groups, although this may have been due to the small size of group 2. TEE is thus a well-tolerated method for postoperative follow-up of type A aortic dissection whatever the type of surgery. For the upper ascending aorta, CT provided sufficient data.

The evaluation of the abdominal aorta: a "how-to" for cardiac sonographers

A thorough evaluation of the abdominal aorta can be readily achieved by use of the standard views of the echocardiographic examination. The ultrasound evaluation of the abdominal aorta represents a logical extension of the standard echocardiographic examination of the adult patient. This article provides the information needed to carry out a complete ultrasound examination of the abdominal aorta including the anatomy, the vascular disease, and the steps involved in accomplishing the ultrasound examination of the abdominal aorta.

Principles of emergency ultrasound and echocardiography

Ultrasound is a form of imaging that addresses many needs in emergency medicine. It is fast, accurate, safe, noninvasive, and painless. It rapidly diagnoses immediately life-threatening conditions and reduces the number of invasive or delayed diagnostic methods. However, successful imaging requires an understanding of ultrasonic principles. The physical principles of ultrasound imaging with emphasis on its limitations and the benefits of emergency echocardiography are highlighted.