Ahmed H. El-Sherief

International association for the study of lung cancer (IASLC) lymph node map: radiologic review with CT illustration.

Accurate clinical or pretreatment stage classification of lung cancer leads to optimal treatment outcomes and improved prognostication. Such classification requires an accurate assessment of the clinical extent of regional lymph node metastasis. Consistent and reproducible regional lymph node designations facilitate reliable assessment of the clinical extent of regional lymph node metastasis. Regional lymph node maps, such as the Naruke lymph node map and the Mountain-Dresler modification of the American Thoracic Society lymph node map, were proposed for this purpose in the past. The most recent regional lymph node map to be published is the International Association for the Study of Lung Cancer (IASLC) lymph node map. The IASLC lymph node map supersedes all previous maps and should be used in tandem with the current seventh edition of the tumor, node, metastasis stage classification for lung cancer.

Mediastinal Lymph Node Staging: From Noninvasive to Surgical

OBJECTIVE The purpose of this review is to describe the current lymph node stations and lymph node staging of non-small cell lung carcinoma. Minimally invasive and invasive methods of mediastinal lymph node staging are emphasized, and the relative accuracy and limitations of each modality are described. CONCLUSION Lung carcinoma remains the most common cause of cancer death in the United States. Accurate staging of lung cancer is imperative for implementing the correct therapy and assessing patient prognosis.

Pertinent reportable incidental cardiac findings on chest CT without electrocardiography gating: review of 268 consecutive cases.

Background Pertinent reportable cardiac findings on non-electrocardiography (ECG)-gated chest CT examinations have become easier to detect given recent advancements in multidetector CT technology. However, those findings are easily overlooked on routine chest CT without ECG gating given residual inherent cardiac motion artifact and non-cardiac indications. Purpose To describe and quantify the types of pertinent reportable cardiac findings that can be detected on chest CT examinations without ECG gating and evaluate how often they were reported. Material and Methods Two radiologists retrospectively reviewed (blinded to the original interpretation) 268 consecutive routine adult chest CT examinations without ECG gating for the presence of pertinent reportable cardiac findings. Retrospective interpretations were then compared with the original radiological reports. Results One hundred and sixty-three patients (61%) had pertinent reportable cardiac findings. The findings encountered included: coronary artery disease (n = 131; 80.0%), coronary artery bypass grafts (n = 10; 6.1%), left ventricular aneurysm (n = 1; 0.6%), valve calcification (n = 131; 80.0%), valve repair/replacement (n = 5; 3.1%), pericardial effusion (n = 33; 20.2%), left atrial appendage thrombus (n = 1; 0.6%), cardiac mass (n = 1; 0.6%), and cardiac chamber enlargement (n = 29; 17.8%). On the original radiological reports 22.3% of the pertinent reportable cardiac findings, detected by the two radiologists retrospectively, were not reported. Conclusion Detection of pertinent reportable cardiac findings on routine chest CT examinations without ECG gating is possible. The high volume of chest CT examinations without ECG gating represents an opportunity for radiologists to comment on the presence or absence of cardiac disease which may influence future clinical decisions.

Imaging of atrial septal defects: echocardiography and CT correlation

Adult patients with atrial septal defects (ASDs) have variable clinical presentations that can range from dyspnoea on exertion to cerebral vascular accidents from paradoxical embolism. Currently echocardiography is the mainstay in the diagnosis and follow-up of patients with ASDs. As CT technology advances and low radiation techniques improve, cardiac CT is becoming a desirable method to evaluate patients with ASDs when echocardiographic evaluation is limited. Correct diagnosis and appropriate management of patients with patent foramen ovales (PFOs) and ASDs relies on an understanding of the embryologic development patterns that resulted in the malformation and associated anomalies. In this review, we illustrate the development of the interatrial septum and the foramen ovale. We discuss the diagnosis of PFOs and ASDs by echocardiography and highlight the incremental benefit of CT to further elucidate defect morphology, associated anomalies, and anatomy post-repair. The primary atrium starts as a common cavity.1 Starting at 5 weeks of gestation, the primordial single atrium begins dividing into right and left sides by formation and fusion of two septa: the septum primum and septum secundum (figure 1). Early in the fifth week of gestation the septum primum begins to form near the centre of the roof of the common atrium, growing downward to the endocardial cushions, and partially dividing the common atrium into right and left counterparts (figure 1, A-1 and A-2). The gap between the septum primum and endocardial cushions is known as the ostium primum. Before the septum primum and endocardial cushions fuse, perforations develop within the cephalic portion of the septum primum through apoptosis, creating a large window known as the ostium secundum. At the end of the sixth week the caudal free edge of the septum primum reaches the atrioventricular cushions and fuses with them, closing the ostium primum (figure 1, B-1 and …

Embryology and Developmental Defects of the Interatrial Septum

OBJECTIVE The various types of atrial septal defects (ASDs) can be differentiated on the basis of their imaging appearance on MDCT. CONCLUSION It is fundamental for the cardiac imager to understand the embryologic development of the interatrial septum and the morphogenic differences of ASDs.

Adult congenital heart disease imaging with second-generation dual-source computed tomography: initial experiences and findings.

Adult congenital heart disease patients present a unique challenge to the cardiac imager. Patients may present with both acute and chronic manifestations of their complex congenital heart disease and also require surveillance for sequelae of their medical and surgical interventions. Multimodality imaging is often required to clarify their anatomy and physiology. Radiation dose is of particular concern in these patients with lifelong imaging needs for their chronic disease. The second-generation dual-source scanner is a recently available advanced clinical cardiac computed tomography (CT) scanner. It offers a combination of the high-spatial resolution of modern CT, the high-temporal resolution of dual-source technology, and the wide z-axis coverage of modern cone-beam geometry CT scanners. These advances in technology allow novel protocols that markedly reduce scan time, significantly reduce radiation exposure, and expand the physiologic imaging capabilities of cardiac CT. We present a case series of complicated adult congenital heart disease patients imaged by the second-generation dual-source CT scanner with extremely low-radiation doses and excellent image quality.

Building a Bridge to Save a Failing Ventricle: Radiologic Evaluation of Short- and Long-term Cardiac Assist Devices

Heart failure is recognized with increasing frequency worldwide and often progresses to an advanced refractory state. Although the reference standard for treatment of advanced heart failure remains cardiac transplantation, the increasing shortage of donor organs and the unsuitability of many patients for transplantation surgery has led to a search for alternative therapies. One such therapy is mechanical circulatory support, which helps relieve the load on the ventricle and thereby allows it to recover function. In addition, there is increasing evidence supporting the use of mechanical devices as a bridge to recovery in patients with acute refractory heart failure. In this article, the imaging evaluation of various commonly used short- and long-term cardiac assist devices is discussed, and their relevant mechanisms of action and physiology are described. Imaging, particularly computed tomography (CT), plays a crucial role in preoperative evaluation for assessment of candidacy for implantation of a left ventricular assist device (LVAD) or total artificial heart (TAH). Also, echocardiography and CT are indispensable in assessment of complications associated with cardiac devices. Complications commonly associated with short-term assist devices include bleeding and malpositioning, whereas long-term devices such as LVADs may be associated with infection, pump thrombosis, and cannula malfunction, as well as bleeding. CT is also commonly performed for preoperative planning before LVAD or TAH explantation, replacement of a device or one of its components, and cardiac transplantation. Online supplemental material is available for this article.

Historical Evolution of Imaging Techniques for the Evaluation of Pulmonary Embolism: RSNA Centennial Article

As we celebrate the 100th anniversary of the founding of the Radiological Society of North America (RSNA), it seems fitting to look back at the major accomplishments of the radiology community in the diagnosis of pulmonary embolism. Few diseases have so consistently captured the attention of the medical community. Since the first description of pulmonary embolism by Virchow in the 1850s, clinicians have struggled to reach a timely diagnosis of this common condition because of its nonspecific and often confusing clinical picture. As imaging tests started to gain importance in the 1900s, the approach to diagnosing pulmonary embolism also began to change. Rapid improvements in angiography, ventilation-perfusion imaging, and cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance imaging have constantly forced health care professionals to rethink how they diagnose pulmonary embolism. Needless to say, the way pulmonary embolism is diagnosed today is distinctly different from how it was diagnosed in Virchows era; and imaging, particularly CT, now forms the cornerstone of diagnostic evaluation. Currently, radiology offers a variety of tests that are fast and accurate and can provide anatomic and functional information, thus allowing early diagnosis and triage of cases. This review provides a historical journey into the evolution of these imaging tests and highlights some of the major breakthroughs achieved by the radiology community and RSNA in this process. Also highlighted are areas of ongoing research and development in this field of imaging as radiologists seek to combat some of the newer challenges faced by modern medicine, such as rising health care costs and radiation dose hazards.

Clear vision through the haze: A practical approach to ground-glass opacity

Ground-glass opacity (GGO) is a common, nonspecific imaging finding on chest computed tomography that may occur in a variety of pulmonary diseases. GGO may be the result of partial filling of alveolar spaces, thickening of the alveolar walls or septal interstitium, or a combination of partial filling of alveolar spaces and thickening of the alveolar walls and septal interstitium at the histopathologic level. Diseases that commonly manifest on chest computed tomography as GGO include pulmonary edema, alveolar hemorrhage, nonspecific interstitial pneumonia, hypersensitivity pneumonitis, and pulmonary alveolar proteinosis. Generating an extensive list of possible causes of GGO in radiologic reports would not be helpful to referring physicians. Preferably, a more concise and focused list of differential diagnostic possibilities may be constructed using a systematic approach to further classify GGO based on morphology, distribution, and ancillary imaging findings, such as the presence of cysts, traction bronchiectasis, and air trapping. Correlation with clinical history, such as the chronicity of symptoms, the patients immune status, and preexisting medical conditions is vital. By thorough analysis of imaging patterns and consideration of relevant clinical information, the radiologist can generate a succinct and useful imaging differential diagnosis when confronted with the nonspecific finding of GGO.

Cardiac CT of non-shunt pathology of the interatrial septum

The development and anatomy of the interatrial septum is complex. With the increasing use of cardiac CT and its precise delineation of the anatomy, it is important for the cardiac imager to become familiar with the normal anatomic structures that compose the interatrial septum and their variants. Furthermore, it is important to recognize pathologic processes occurring in this region other than atrial septal defects and potential imaging pitfalls. This pictorial essay provides a detailed review of these topics with emphasis in CT appearance and related technical aspects.