ACR Appropriateness Criteria®
Clinical Condition: Acute Chest Pain: No ECG or Enzyme Evidence of Myocardial Ischemia/Infarction
| Radiologic Exam Procedure |
Appropriateness Rating |
Comments |
| X-ray, chest |
9 |
|
| NUC, myocardial perfusion scan |
8 |
If myocardial etiology is suspected. |
| CT, chest, multi detector (MDCT) |
8 |
Useful to rule out other sources for chest pain such as aortic dissection, pulmonary embolism, etc. |
| US, transthoracic echocardiography (TTE) |
6 |
If CT is non-diagnostic. |
| US, transesophageal echocardiography (TEE) |
6 |
To exclude aortic dissection. Especially if MDCT or MRI are not diagnostic and/or not available. |
| CT, chest, single detector |
6 |
|
| MRI/MRA, aortic |
6 |
|
| INV, catheter pulmonary angiography |
6 |
If MDCT is non-diagnostic and pulmonary embolism is suspected. |
| NUC, V/Q scan |
5 |
May be appropriate if contrast administration is contraindicated. |
| X-ray, barium swallow and upper GI series |
4 |
|
| X-ray, rib |
4 |
|
| X-ray, cervical spine |
4 |
|
| X-ray, thoracic spine |
4 |
|
| US, stress echocardiography |
4 |
May be indicated if cardiac etiology is still suspected after negative CXR and MDCT. |
| US, gall bladder |
4 |
|
| US, peripheral venous |
4 |
|
| MRA, pulmonary artery |
4 |
|
| PET, cardiac |
4 |
|
| Aortogram, thoracic |
4 |
Unless results of less invasive tests are equivocal. |
| INV, coronary angiography with LV gram |
4 |
Last choice for evaluation. Only if other tests are equivocal. Depends on noninvasive test. |
| NUC, bone scan |
2 |
|
Appropriateness Criteria Scale
1 2 3 4 5 6 7 8 9
1 = Least appropriate 9 = Most appropriate
|
Note: Abbreviations used in the table are listed at the end of the "Major Recommendations" field.
Introduction
Patients frequently present to emergency departments with the classical anginal symptoms of chest tightness and left arm pain. If these symptoms are present and if an ECG shows evidence of ischemia, a cardiac etiology for the chest pain is favored. Ischemic pain can also masquerade as indigestion, muscle spasm, or myriad other complaints. Many patients, however, present with chest pain without strong evidence of a cardiac etiology, that is, with a normal or nondiagnostic ECG and serum markers (i.e., troponins). In such patients, other diagnoses need to be considered, and other imaging modalities need to be utilized.
Imaging modalities useful in evaluating patients presenting to the emergency department without ECG or troponin evidence of myocardial infarction/angina, but with suspected cardiac origin for the chest pain are chest film, TEE and TTE, thallium 201 and technetium 99m perfusion studies, positron emission tomography, technetium 99m pyrophosphate infarct avid imaging, radionuclide ventriculography, cardiac catheterization, and the CT determination of coronary calcium. Imaging modalities to evaluate what are thought to be noncardiac causes of chest pain include cervical and thoracic spine films, barium upper GI studies, radionuclide esophageal transit time studies, pulmonary angiography, V/Q scans, CT spine, aortic, and pulmonary artery studies, MRI spine and aortic studies, abdominal ultrasound, and possibly mammography.
Chest Film
The chest film is extremely important in evaluating patients presenting to the emergency room with chest pain, and it is usually the initial imaging study obtained. Plain chest films can be diagnostic in pneumothorax, pneumomediastinum, fractured ribs, acute or chronic infections, and malignancies. Other conditions producing chest pain, such as aortic aneurysms or dissections and pulmonary emboli, may be suspected from the chest film, but the overall sensitivity is very low.
Calcifications may indicate pericardial disease, ventricular aneurysms, intracardiac thrombi, or aortic disease. The presence of a Hampton hump, Westermark sign, or pulmonary artery enlargement may indicate pulmonary embolism. Mediastinal air may indicate a ruptured viscus or rupture of a subpleural bleb.
Transthoracic and Transesophageal Echocardiography
TTE and TEE with or without pharmacologic stress can help define a cardiac origin for chest pain when abnormalities of ventricular wall motion are present. TTE may additionally be helpful in diagnosing pericarditis, pericardial effusion, valvular dysfunction, and/or intracardiac thrombus. TTE is helpful in diagnosing aortic dissection, intracardiac thrombus, and valvular dysfunction. With TEE, the arch of the aorta and the upper abdominal aorta are less well visualized; however, the ascending and descending aorta are usually well seen. In a small number of patients, mitral valve prolapse may be the cause for the chest pain, and this condition could be recognized using transesophageal echocardiography. Pharmacologic stress can add an additional element of risk stratification to the echocardiographic examination, particularly if coronary artery occlusive disease remains a concern.
Conventional, Helical, and Electron Beam Computed Tomography
Conventional CT can be diagnostic in pneumothorax, pneumonia, malignancies, and chronic pulmonary disorders such as fibrosis and granulomatous disease. It can also help to confirm central pulmonary emboli, pulmonary infarcts, and aortic aneurysms and dissections. Complications of aortic aneurysms such as leaks are also identifiable with CT. Pericardial effusions, thickening, and calcifications are readily seen. Electron beam CT and helical CT are additionally helpful by diagnosing coronary artery calcification (atherosclerosis) as the possible cause of the chest pain, although specificity is low. Conversely, the absence of calcium is an excellent indicator of the absence of significant coronary stenosis. Both types of CT have additional utility in defining ventricular aneurysms, wall motion abnormalities, and thrombus resulting from myocardial infarction. CT angiography (CTA) is gaining utility in evaluating coronary stenosis and detecting the presence of anomalous coronary arteries. MDCT is the current standard rather than single-slice CT.
Cervical and Thoracic Spine Films
Films of the cervical and thoracic spine may be indicated to establish vertebral abnormalities (e.g., vertebral body collapse or fracture) as a cause of chest pain.
Radionuclide Studies
Myocardial perfusion studies using thallium 201, technetium 99m sestamibi, or tetrofosmin scintigraphy can identify perfusion abnormalities and help in establishing a cardiac cause for the chest pain.
Radionuclide ventriculography can also help establish a cardiac etiology for the chest pain by demonstrating abnormalities of ventricular wall motion secondary to ischemia/infarction.
Infarct avid imaging with technetium 99m pyrophosphate can identify acute myocardial infarction at 12-36 hours after infarct by showing radioactive tracer uptake at the infarction site.
Positron emission tomography can reliably show myocardial perfusion deficits using N13 ammonia agents and can document anaerobic myocardial metabolism using F18 fluorodeoxyglucose. Again, these tests may be of help in the patient suspected of having a cardiac etiology for the chest pain and in whom the ECG and troponin are nondiagnostic.
Magnetic Resonance
MRI has utility in demonstrating spinal abnormalities and nerve root compression as a cause of chest pain. It also has utility in demonstrating myocardial wall motion abnormalities and/or pericardial thickening and effusion. At times intracardiac thrombi can be seen; however, other tests are usually better for establishing cardiac etiologies as the source of the chest pain. Magnetic resonance perfusion agents can show either a "cold spot" of myocardial infarction with the use of T1 enhancing agents or a "hot spot," using magnetic susceptibility agents. These techniques may be helpful in establishing a cardiac etiology for the chest pain where the ECG and troponin are either negative or nondiagnostic. MR imaging incorporating dobutamine and other pharmacologic stress agents increases sensitivity in determining a cardiac etiology for chest pain.
Cardiac Catheterization
Cardiac catheterization with coronary angiography is the "gold standard" for demonstrating coronary pathology. This is usually the final diagnostic test in defining heart disease, although MDCT has recently shown promise as an accurate noninvasive alternative, particularly if the diagnosis is in question.
Barium Swallow/Endoscopy
Esophageal disorders may be the cause of chest pain in patients presenting to the emergency department with symptoms typical of angina but with negative ECG and troponins. A barium swallow or endoscopy and, in some cases, radionuclide transit studies may be of help in diagnosing esophageal spasm or reflux as an etiology of the chest pain.
Abdominal Plain Films
In limited instances, cholecystitis or cholangitis, renal disease, perforated viscus, or diaphragmatic abnormalities may be an etiology for chest pain. These disorders can often be suspected from an abdominal plain film.
Abdominal Ultrasonography
Abdominal ultrasound may be indicated in establishing cholecystitis as a cause for the chest pain. Ultrasound is also helpful in evaluating pancreatitis and/or abscesses and other fluid collections.
Pulmonary Angiography
Pulmonary angiography had been considered to be the definitive test in patients with suspected pulmonary embolism. Multidetector CT angiography has largely replaced catheter pulmonary angiography. In addition to being noninvasive and having the ability to demonstrate smaller emboli, it has the added advantage of demonstrating other abnormalities that may be the cause of the chest pain, such as neoplasm or pulmonary airspace disease. The ventilation/perfusion scan is rapidly being replaced by MDCT. At times it can be additionally helpful in establishing pulmonary embolism as the etiology for the chest pain, although it is now generally reserved for patients who cannot undergo CT pulmonary angiography.
Mammography
On rare occasions fat necrosis or breast abscess can masquerade as angina. If these conditions are suspected, a mammogram, breast ultrasound, or MR studies may be indicated.
Aortography
As with pulmonary angiography, catheter-based aortography had been considered the definitive imaging procedure in patients with aortic dissection or aneurysmal disease. It has now been almost completely replaced by CTA or MRA, as both are rapid, noninvasive, and able not only to define the aortic lumen but also to characterize the aortic wall and other pathology.
Summary
Although the patient's history is the most important factor in establishing the etiology in patients presenting to the emergency department with chest pain, other imaging modalities are frequently used. The chest film is almost universally obtained; CT, MRI, radionuclide studies, barium swallow, spine studies, plain films, and angiography are useful when specific diagnoses are considered.
Abbreviations
- CT, computed tomography
- CXR, chest x-ray
- ECG, electrocardiogram
- GI, gastrointestinal
- INV, invasive
- LV, left ventricular
- MDCT, multidetector computed tomography
- MRA, magnetic resonance angiography
- MRI, magnetic resonance imaging
- NUC, nuclear medicine
- PET, positron emission tomography
- TEE, transesophageal echocardiography
- TTE, transthoracic echocardiography
- US, ultrasound
- V/Q, ventilation/perfusion scan
