Coronary CT Calcium Score in Patients With Prior Nongated CT, Is it Necessary?

PURPOSE: To evaluate the percentage of patients undergoing gated coronary artery calcium score CTs that had a prior nongated chest CT. To assess the accuracy of prior nongated chest CTs in the detection of coronary calcium. BACKGROUND: Cardiovascular disease is the most common cause of death worldwide. Quantifying coronary artery calcification on gated calcium score CT has proven to be strongly predictive of adverse coronary artery disease events. However, visual estimation and ordinal scoring on nongated chest CTs is predictive of coronary calcium burden. METHODS: Consecutive gated calcium score CTs at a single institution from 10/2014 to 10/2016 were retrospectively evaluated with IRB approval/waiver of informed consent. The presence or absence of coronary calcium and ordinal score on nongated chest CT was compared to Agatston score on gated calcium score CT. RESULTS: Forty-two of 441 patients (9.5%) with a gated calcium score had a prior nongated chest CT, with a mean time difference of 810 days. Of the 42 prior chest CTs, 69% had coronary artery calcium (CAC) and 31% did not, with 100% predictive accuracy for the presence or absence of CAC on subsequent gated calcium score CTs. There was 86% correlation of Agatston score on gated calcium score CT with ordinal score on the prior chest CT. Ordinal score divided into independent groups of severity was related to increased severity of Agatston score on the gated calcium score CT (P< 0.001). A majority of prior chest CT studies with coronary calcium failed to include this information in the final report. CONCLUSIONS: A large percentage of gated calcium score CTs were performed despite a prior chest CT. The ordinal score on chest CTs correlated with Agatston score on gated calcium score CTs. The presence of CAC on chest CTs was underreported in a majority of cases.

ACR Appropriateness Criteria® Chronic Chest Pain-Noncardiac Etiology Unlikely-Low to Intermediate Probability of Coronary Artery Disease.

Chronic chest pain (CCP) of a cardiac etiology is a common clinical problem. The diagnosis and classification of the case of chest pain has rapidly evolved providing the clinician with multiple cardiac imaging strategies. Though scintigraphy and rest echocardiography remain as appropriate imaging tools in the diagnostic evaluation, new technology is available. Current evidence supports the use of alternative imaging tests such as coronary computed tomography angiography (CCTA), cardiac MRI (CMRI), or Rb-82 PET/CT. Since multiple imaging modalities are available to the clinician, the most appropriate noninvasive imaging strategy will be based upon the patient's clinical presentation and clinical status. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Suspected New-Onset and Known Nonacute Heart Failure.

While there is no single diagnostic test for heart failure (HF), imaging plays a supportive role beginning with confirmation of HF, especially by detecting ventricular dysfunction (Variant 1). Ejection fraction (EF) is important in HF classification, and imaging plays a subsequent role in differentiation between HF with reduced EF (HFrEF) versus preserved EF (HFpEF) (Variant 2). Once HFrEF is identified, distinction between ischemic and nonischemic etiologies with imaging support (Variant 3) facilitates further planning. Imaging approaches which are usually appropriate include: both resting transthoracic echocardiography (TTE) and chest radiography for Variant 1; resting TTE and/or MRI (including functional, without absolute need for contrast) for Variant 2; and for Variant 3, a. Coronary CTA or coronary arteriography (if high pretest probability/symptoms for ischemic disease) for coronary assessment; b. Rest/vasodilator stress SPECT/CT, PET/CT, or MRI for myocardial perfusion assessment; c. Rest/exercise or inotropic stress TTE for myocardial contraction assessment; or d. MRI (including morphologic with contrast) for myocardial characterization. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Spectrum of Coronary Artery Aneurysms: From the Radiologic Pathology Archives.

Advances in medical diagnosis reveal that coronary artery aneurysms (CAAs) may develop in several clinical scenarios and manifest variable symptoms, imaging appearances, and outcomes. Aneurysms are pathologically classified into three groups: atherosclerotic, inflammatory, and noninflammatory. The last category is associated with congenital, inherited, and connective tissue disorders. Overlap exists among the groups, because secondary atherosclerotic change may be present in an aneurysm of any cause. Atherosclerosis is the most common cause of CAAs in adults, and inflammation is considered the underlying mechanism. In children, Kawasaki disease is the most likely cause of CAAs. In both conditions, the aneurysms are usually multiple and affect more than one coronary artery. Mycotic (infectious), iatrogenic, and cocaine-induced CAAs are also well documented. Most CAAs are discovered incidentally, but potential cardiovascular complications include thrombosis, occlusion, fistula formation, rupture, myocardial infarction, and cardiac tamponade. Imaging modalities to evaluate a suspected CAA include transthoracic echocardiography, angiographic cardiac catheterization, electrocardiographically gated computed tomographic angiography, cardiac magnetic resonance (MR) imaging, and MR angiography. Management is usually individualized, and options include surveillance, anticoagulant therapy, percutaneous stent or coil placement, surgical resection, and coronary artery bypass grafting.

ACR Appropriateness Criteria® Dyspnea-Suspected Cardiac Origin.

This article discusses imaging guidelines for five dyspnea variants: (1) dyspnea due to heart failure, ischemia not excluded; (2) dyspnea due to suspected nonischemic heart failure, ischemia excluded; (3) dyspnea due to suspected valvular heart disease, ischemia excluded; (4) dyspnea due to suspected cardiac arrhythmia, ischemia excluded; and (5) dyspnea due to suspected pericardial disease, ischemia excluded. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Acute Chest Pain-Suspected Pulmonary Embolism.

Pulmonary embolism (PE) remains a common and important clinical condition that cannot be accurately diagnosed on the basis of signs, symptoms, and history alone. The diagnosis of PE has been facilitated by technical advancements and multidetector CT pulmonary angiography, which is the major diagnostic modality currently used. Ventilation and perfusion scans remain largely accurate and useful in certain settings. Lower-extremity ultrasound can substitute by demonstrating deep vein thrombosis; however, if negative, further studies to exclude PE are indicated. In all cases, correlation with the clinical status, particularly with risk factors, improves not only the accuracy of diagnostic imaging but also overall utilization. Other diagnostic tests have limited roles. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Sudden Cardiac Arrest in a Patient With Apical Hypertrophic Cardiomyopathy: Case Report and a Brief Review of Literature.

Apical hypertrophic cardiomyopathy (HCM) is a phenotypic variant of nonobstructive HCM, in which hypertrophy of the myocardium predominantly involves the left ventricular apex. It is common in Japanese and other Asian populations but is rare in the United States. Apical HCM has a relatively benign prognosis in terms of cardiovascular mortality; however, morbid events such as ventricular aneurysms, apical thrombi, diastolic dysfunction, atrial fibrillation, and myocardial infarction are not uncommon. We report a case of an 18-year-old white man who presented to our hospital after an out-of-hospital cardiac arrest. The patient had a witnessed collapse while playing basketball in the field. He was found to be pulseless and unresponsive by his coach, and cardiopulmonary resuscitation was immediately started. Upon arrival of emergency medical services, an automated external defibrillator advised shock and he was defibrillated thrice. Return of spontaneous circulation was achieved in 15 minutes. He was intubated for airway protection and was brought to the hospital. Therapeutic hypothermia was initiated. He demonstrated good neurological status after active rewarming. Subsequent cardiac magnetic resonance imaging was suggestive of apical HCM with right ventricular involvement. The patient underwent an implantable cardioverter defibrillator placement for secondary prevention and was subsequently discharged. In conclusion, apical HCM can rarely be associated with adverse cardiovascular events. The diagnosis may be missed on transthoracic 2-dimensional cardiac echocardiogram, and cardiac magnetic resonance imaging should be considered to exclude apical HCM in young patients who present after sudden cardiac arrest.

MDCT of endoleaks following endovascular repair of abdominal aortic aneurysms.

Endovascular aneurysm repair has been used to repair abdominal aortic aneurysms but necessitates surveillance to diagnose the delayed possibility of endoleak formation. Multi-detector computer tomography (MDCT) of the abdomen is one imaging technique used to diagnose enlargement of the aneurysm sac that may be indicative of endoleaks. MDCT has a role in identifying the initial endoleak formation and providing signs suggestive of the specific endoleak subtype; thus it is necessary for radiologists to be familiar with the findings of endoleak seen on MDCT. In this pictorial review, we explore the various types of endoleaks and their appearance on MDCT.

The right atrium: gateway to the heart--anatomic and pathologic imaging findings.

Knowledge of right atrial anatomic and pathologic imaging findings and associated clinical symptoms is important to avoid false-positive diagnoses and missed findings. Complete evaluation of the heart often requires a multimodality approach that includes radiography, echocardiography, computed tomography (CT), magnetic resonance (MR) imaging, and invasive angiography. In general, CT provides the highest spatial resolution of these modalities at the cost of radiation exposure to the patient. Echocardiography and MR imaging offer complementary and detailed information for functional evaluation without added radiation exposure. The advantages and disadvantages of each modality for the evaluation of right atrial anatomic structure, size, and pathologic findings are discussed. Cardiac MR imaging is the reference standard for evaluation of right atrial size and volume but often is too time consuming and resource intensive to perform in routine clinical practice. Therefore, established reference ranges for two-dimensional transthoracic echocardiography are often used. Right atrial pathologic findings can be broadly categorized into (a) congenital anomalies (cor triatriatum dexter, Ebstein anomaly, and aneurysm), (b) disorders of volume (tricuspid regurgitation, pathologic mimics such as a pseudoaneurysm, and atrial septal defect), (c) disorders of pressure (tricuspid stenosis, restrictive cardiomyopathy, and constrictive pericarditis), and (d) masses (pseudomasses, thrombus, lipomatous hypertrophy of the interatrial septum, lipoma, myxoma, sarcoma, and metastatic disease). Familiarity with each pathologic entity and its treatment options is essential to ensure that appropriate imaging modalities are selected. Online supplemental material is available for this article.

ACR appropriateness criteria® nonischemic myocardial disease with clinical manifestations (ischemic cardiomyopathy already excluded).

Nonischemic myocardial disease or cardiomyopathy can present as arrhythmia, palpitations, heart failure, dyspnea, lower extremity edema, ascites, syncope, and/or chest discomfort and can be classified as either systolic, diastolic, or a combination of both. Echocardiography is the mainstay of evaluating left ventricular function. However, cardiac magnetic resonance imaging (MRI) is now considered the reference standard imaging technique to assess myocardial anatomy, function, and viability. Advanced MRI techniques with delayed myocardial enhancement, especially, can provide information beyond echocardiography for tissue characterization in CM and can assist in determining specific etiology or in narrowing the differential. Often imaging enhancement patterns, signal characteristics, and morphology on MRI can lead to specific diagnoses such as amyloidosis, hypertrophic CM, or iron deposition. Cardiac computed tomography is usually used in excluding coronary artery disease but can also be used in some patients unable to undergo cardiac MRI to assess arrhythmogenic right ventricular dysplasia. Both 18-F-fluoro-2-deoxyglucose positron emission tomography and delayed contrast-enhanced MRI can be used to assess for cardiac sarcoidosis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR Appropriateness Criteria chronic chest pain-low to intermediate probability of coronary artery disease.

Chronic chest pain can arise from a variety of etiologies. However, of those potential causes, the most life-threatening include cardiac disease. Chronic cardiac chest pain may be caused either by ischemia or atherosclerotic coronary artery disease or by other cardiac-related etiologies, such as pericardial disease. To consider in patients, especially those who are at low risk for coronary artery disease, are etiologies of chronic noncardiac chest pain. Noncardiac chest pain is most commonly related to gastroesophageal reflux disease or other esophageal diseases. Alternatively, it may be related to costochondritis, arthritic or degenerative diseases, old trauma, primary or metastatic tumors, or pleural disease. Rarely, noncardiac chest pain may be referred pain from organ systems below the diaphragm, such as the gallbladder. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Imaging of neuroendocrine tumors.

Neuroendocrine tumors (NETs) constitute a large group of diverse neoplasms with a wide spectrum of clinical, imaging, and pathologic findings. Imaging diagnosis of NETs can be challenging, and several complementary imaging modalities may be needed during the diagnostic workup. Accurate interpretation of the imaging findings is important to facilitate diagnosis and contribute to patient management. This article discusses the gastrointestinal site-specific features and the tumor-specific features of several NETs and the role of several imaging modalities such as computed tomography, MR imaging, ultrasonography, and positron emission tomography in the evaluation of these NETs.

Use of 100 kV versus 120 kV in cardiac dual source computed tomography: effect on radiation dose and image quality.

To evaluate the effective radiation dose and image quality resulting from use of 100 vs. 120 kV among patients referred for cardiac dual source CT exam (DSCT). Prospective data was collected on 294 consecutive patients referred for DSCT. For each scan, a physician specializing in cardiac CT chose all parameters including tube current and voltage, axial versus helical acquisition, and use of tube current modulation. Lower tube voltage was selected for thinner patients or when lower radiation was desired for younger patients, particularly females. For each study, image quality (IQ) was rated on a subjective IQ score and contrast (CNR) and signal-to-noise (SNR) ratios were calculated. Tube voltage of 100 kV was used for 77 (26%) exams while 120 kV was used for 217 (74%) exams. Use of 100 kV was more common in thinner patients (weight 166 lbs vs. 199 lbs, P < .001). The effective radiation dose for the 100 and 120 kV scans was 8.5 and 15.4 mSv respectively. Among scans utilizing 100 and 120 kV, there was no difference in exam indication, use of beta blockers, heart rate, scan length and use of radiation saving techniques such as prospective ECG triggering and tube current modulation. The IQ score was significantly higher for 100 kV scans. While 100 kV scans were found to have higher image noise then those utilizing 120 kV, the contrast-to-noise and signal-to-noise were significantly higher (SNR: 9.4 vs. 8.3, P = .02; CNR: 6.9 vs. 6.0, P = .02). In selected non-obese patients, use of low kV results in a substantial reduction of radiation dose and may result in improved image quality. These results suggest that low kV should be used more frequently in non-obese patients.