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Introduction F (FDG) positron emission tomography (PET)/computed tomography (CT) is widely used in current clinical practice. Most of the PET/CT applications in the thorax involve the evaluation of solitary pulmonary nodules for malignancy, staging and restaging of oncologic patients, assessment of treatment response following therapy, and identification of residual or recurrent disease. These functions reflect the fact that cancer cells demonstrate increased uptake of glucose and glucose analogues such as FDG, as well as an increased rate of glycolysis. Although FDG undergoes uptake by the same transporter proteins as glucose, it becomes sequestered in cancer cells owing to its inability to participate in glycolytic pathways. The standardized uptake value (SUV) based on body weight, defined as the ratio of radiotracer accumulation (mCi/mL) in the area of interest divided by the injected dose (mCi) normalized by the patient’s bodyweight (g), is themost common semiquantitativemethod of evaluating abnormalities on PET/CT. Studies have suggested that an SUV cutoff of 2.5 can be used to separate benign from malignant abnormalities.

Background and Relevance Atherosclerosis is an immune-inflammatory process with lipid andfibrous accumulationwithin the intimal layer of medium-sized and large arteries, resulting in plaque deposition. In the coronary arteries, most plaques remain silent; but some become obstructive, resulting in a coronary event. “Hard” coronary events include unstable angina, myocardial infarction (MI), and sudden death, which are also regarded as acute coronary syndrome (ACS). “Soft” coronary events are considered minor adverse events, such as stable angina, revascularization, or percutaneous catheter insertion. Atherosclerosis, seen inmost of the adult population all over the world, accounts for more than 19 million deaths every year. Despite the decrease in mortality from coronary heart disease (CHD) in the United States, CHD still remains the leading cause of death in both men and women with approximately 600,000 people dying every year. Cardiovascular disease and stroke cumulatively cause more annual deaths than cancer, respiratory disease, accidents, and diabetes combined. The cost of the US health care system related to cardiovascular disease was estimated to be more than $400 billion in 2008. The reduction inCHD-relatedUS deaths from1980-2000 is attributed equally to improvedmajor risk factors and to the use of evidence-based medical therapies. The latter category, focused on secondary prevention, has been the most dramatic advance in reducing the likelihood of recurrentmajor coronary

Computed tomography (CT), 18 F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT), magnetic resonance (MR) imaging, and minimally invasive procedures such as endobronchial ultrasound–guided fine-needle aspiration and mediastinoscopy have increased the accuracy of clinical staging of non–small cell lung cancer (NSCLC). Typically, CT is used to assess the anatomical extent of the disease and optimally evaluate the primary tumor, FDG-PET improves the detection of nodaland extrathoracic metastatic disease, and MR imaging can be used to evaluate tumor extension into the chest wall and brachial plexus. 1 However, although the accuracy of staging is important in determining the appropriate management of patients, the performance of different imaging studies varies. For example, CT has low sensitivity and specificity to detect nodal metastatic disease, whereas FDG-PET offers limited anatomical information. These limitations can potentially affect the accuracy of the seventh American Joint Committee on Cancer tumor-node-metastasis staging system for NSCLC. In this article, we review potential pitfalls and limitations of imaging that can affect the accuracy of initial staging in patients with NSCLC and their implications in oncologic management.

Pulmonary embolism (PE) is considered the third most common acute cardiovascular disease after myocardial infarction and stroke.Most preventable deaths associatedwith PE can be attributed to missed diagnosis, rather than therapy failure; thus, accurate and fast diagnosis of PE is important and greatly influences patient outcome. Computed tomography pulmonary angiography (CTPA) was first introduced as a diagnostic test for PEwith the arrival of helical CT scanners in the early 1990s. Less than a decade later, with improvements in resolution, acquisition speed, and image quality, multidetector CTPA (MDCTPA) became the most used diagnostic modality in the evaluation of PE. In 2007, the Fleischner Society declared that MDCTPA had fulfilled the conditions to replace conventional pulmonary angiography as the standard of reference for diagnosing acute PE. The recent introduction of dual-source MDCT technology adds functional assessment to the established anatomical evaluation, potentially further enhancing the capability of CTPA to determine the presence and clinical significance of pulmonary thromboembolism. The sensitivity and specificity for the diagnosis of PE since the era of single-slice helical CTPA has improved from 53%91% and 78%-97%, respectively, to 83%-100% and 89%97%, respectively, with MDCTPA. Several studies on single-slice and early-generation MDCTPA have reported “indeterminate” results ranging from 0.5%-10%, with a mean at approximately 6%. In a more recent study with 40-slice MDCT, 3.2% of 220 consecutive reports were deemed