Radiographics current issue

[Online Only] Radiologic and Clinical Findings of Behcet Disease: Comprehensive Review of Multisystemic Involvement

2008-09-15

Behçet disease is a chronic, relapsing, systemic disorder of unknown etiology, characterized by recurrent oral and genital ulcers, uveitis, and other clinical manifestations in multiple organ systems. Although the diagnosis is made on the basis of the combination of typical clinical symptoms, radiologic findings of Behçet disease show characteristic features of its involvement in the gastrointestinal, neurologic, cardiovascular, and thoracic organ systems. In the gastrointestinal tract, Behçet disease may produce various types of ulcers in the esophagus, stomach, and small and large intestines, as well as deeply penetrating ulcerations in the ileocecal region, with frequently accompanying enteric fistulas. Neurologic involvement includes typical and atypical parenchymal neurobehcet disease, dural sinus thrombosis, cerebral arterial aneurysm, occlusion, dissection, and meningitis. Vascular involvement is divided into three subsets including venous occlusion, arterial occlusion, and arterial aneurysm. Cardiac manifestations include intracardiac thrombus, endomyocardial fibrosis, periaortic pseudoaneurysm, and rupture of the sinus of Valsalva. Manifestations of Behçet disease in the thorax include pulmonary arterial aneurysm, pulmonary arterial thromboembolism, thrombosis in the superior vena cava, pulmonary infarction, hemorrhage, and vasculitis of the pleura and pericardium. These various manifestations of Behçet disease respond to steroid treatment; however, one of the characteristics of Behçet disease is the high rate of complications and recurrence after surgery. Familiarity with its various radiologic and clinical characteristics is essential in making an accurate early diagnosis and for prompt treatment of patients with Behçet disease.

[Quality Initiatives] Managing an Acute Adverse Event in a Radiology Department

Kruskal, J. B., Siewert, B., Anderson, S. W., Eisenberg, R. L., Sosna, J. — 2008-09-16

Many local and national regulatory organizations require that all serious adverse events be promptly investigated, managed, and reported, with the first goal being to institute actions to prevent or minimize the occurrence of similar events. However, the tools and processes necessary for effective incident review and management have been developed largely by industrial organizations, and radiologists may not be familiar with such processes. Data analysis requires a root cause analysis to identify all possible active and latent contributors to the event, as well as the use of algorithms to determine the degree of responsibility when human error is implicated. Acceptable corrective actions that are reasonable, achievable, and measurable should be instituted. These changes should be monitored according to defined timelines by a designated person. In some cases, additional training or even remediation may be required. Subsequently, the focus should be on actively managing and improving error detection and reporting systems, as well as on seeking strategies for minimizing the occurrence of preventable errors.

[Informatics] Informatics in Radiology: An Inexpensive Distance Learning Solution for Delivering High-Quality Live Broadcasts

Jeun, B. S., Javan, R., Gay, S. B., Olazagasti, J. M., Bassignani, M. J. — 2008-09-16

Providing an adequate method of distance learning is a challenge faced by many multicenter residency programs. The delivery of live didactics over the Internet is a convenient means of providing a uniform and equivalent educational experience to residents at distant sites. An application called MedCast has been developed with use of existing technologies, without the need for costly commercial products or equipment. MedCast captures the presenter’s computer screen and audio from a microphone source to produce a streaming video that is transmitted online and archived on a local server. Offsite residents can view broadcasts in real time or access archived conference sessions for later viewing. MedCast is available for download at no cost and offers several advantages, including a user-friendly graphical display interface, near-perfect preservation of image quality, and cost efficiency. Future plans include objective assessment of the efficacy of MedCast by comparing postlecture examinations to help evaluate for any differences between on- and offsite residents in terms of knowledge gained. A movie clip to supplement this article is available online at http://radiographics.rsnajnls.org/cgi/content/full/28/5/285085701/DC1.

[Editorials] Increasing User Satisfaction with Healthcare Software

Flanders, A. E. — 2008-09-15

[Illuminations] Nasal Airway

Fung, K.-h. — 2008-09-15

[RSNA Education Exhibits] Cholangiocarcinoma: Current and Novel Imaging Techniques

2008-09-15

The radiologic manifestations of cholangiocarcinomas are extremely diverse, since these tumors vary greatly in location, growth pattern, and histologic type. Familiarity with the imaging manifestations of cholangiocarcinomas is important for accurate detection and characterization of these tumors and assessment of resectability. Advances in imaging techniques have led to the availability of an array of modalities that, used independently or in combination, can aid in the accurate diagnosis and evaluation of cholangiocarcinomas in preparation for advanced surgical procedures and treatment planning. Response to novel targeted therapies can also be assessed with newer imaging tools. Hence, knowledge of current and emerging imaging applications is essential for correct diagnosis and appropriate management of these tumors.

[RSNA Education Exhibits] The Diaphragmatic Crura and Retrocrural Space: Normal Imaging Appearance, Variants, and Pathologic Conditions

Restrepo, C. S., Eraso, A., Ocazionez, D., Lemos, J., Martinez, S., Lemos, D. F. — 2008-09-15

The retrocrural space (RCS) is a small triangular region within the most inferior posterior mediastinum bordered by the two diaphragmatic crura. Multiplanar imaging modalities such as computed tomography and magnetic resonance imaging allow evaluation of the RCS as part of routine examinations of the chest, abdomen, and spine. Normal structures within the retrocrural region include the aorta, nerves, the azygos and hemiazygos veins, the cisterna chyli with the thoracic duct, fat, and lymph nodes. There is a wide range of normal variants of the diaphragmatic crura and of structures within the RCS. Diverse pathologic processes can occur within this region, including benign tumors (lipoma, neurofibroma, lymphangioma), malignant tumors (sarcoma, neuroblastoma, metastases), vascular abnormalities (aortic aneurysm, hematoma, azygos and hemiazygos continuation of the inferior vena cava), and abscesses. An understanding of the anatomy, normal variants, and pathologic conditions of the diaphragmatic crura and retrocrural structures facilitates diagnosis of disease processes within this often overlooked anatomic compartment.

[Editorials] Resident Learning Portfolio

Bisset, G. S., Bresolin, L. B. — 2008-09-15

[RSNA Education Exhibits] Hepatic Capsular and Subcapsular Pathologic Conditions: Demonstration with CT and MR Imaging

2008-09-15

A variety of pathologic conditions and pseudolesions occur at the capsular and subcapsular regions of the liver and are detected with cross-sectional abdominal imaging. These entities are related to anatomic and hemodynamic characteristics of the liver such as negative subdiaphragmatic pressure, connection with other viscera and extraperitoneal sites by the perihepatic ligaments, and a "third inflow" of blood from sources other than the usual hepatic arterial and portal venous sources. Pathologic conditions can affect the hepatic capsular and subcapsular regions by way of peritoneal, hematogenous, biliary, and perihepatic ligamentous routes. Pseudolesions or benign conditions may also be identified on the basis of altered hemodynamics of the liver. Computed tomography and magnetic resonance imaging with a multiphasic approach can be used to identify and characterize these entities. Familiarity with the wide spectrum of pathologic conditions and pseudolesions at the hepatic capsular and subcapsular regions and precise knowledge of the anatomic and hemodynamic characteristics of the liver will aid the radiologist in diagnosing pathologic conditions and differentiating pseudolesions from true lesions.

[Editorials] Practice Corner * Apocalypse Soon?

Heilman, R. S. — 2008-09-15

[RSNA Education Exhibits] Pitfalls in Renal Mass Evaluation and How to Avoid Them

Israel, G. M., Bosniak, M. A. — 2008-09-15

Characterization of renal masses with computed tomography (CT) and magnetic resonance (MR) imaging is usually clear-cut and accurate. However, potential pitfalls exist in diagnosis of renal masses, and it is necessary to understand these pitfalls to avoid misdiagnosis and possibly unnecessary surgery. Although some of the pitfalls are related to technical factors of the CT and MR imaging equipment, others are related to errors in image interpretation. To maximize detection and characterization of renal masses, the study should include images obtained before and after administration of intravenous contrast material, including images obtained during the nephrographic phase of enhancement. One should be aware of the potential unreliability of absolute Hounsfield unit measurements and of the existence of possible CT pseudoenhancement. When CT results are indeterminate, MR imaging may be helpful in demonstrating enhancement in renal masses. Before diagnosing a renal mass as a malignant neoplasm or suggesting surgery for a renal mass, one should consider alternative benign diagnoses; when appropriate, previous images or a supporting history should be obtained.

[RSNA Education Exhibits] Imaging and Histopathologic Features of HIV-related Renal Disease

Symeonidou, C., Standish, R., Sahdev, A., Katz, R. D., Morlese, J., Malhotra, A. — 2008-09-15

Despite extraordinary recent advances in the management of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome, patients infected with HIV are still susceptible to a variety of complications that stem either from immunodeficiency or from side effects of antiretroviral regimens. Diagnosis is often challenging, since every organ in the body can be affected by HIV, and the kidneys have been increasingly shown to be involved by a variety of disease processes. Opportunistic infections including those caused by atypical organisms, malignancies such as lymphoma and Kaposi sarcoma, and disease processes specific to HIV infection such as HIV-associated nephropathy have all been shown to affect the kidneys. In this era of highly active antiretroviral therapy (HAART), renal disease arising secondary to antiretroviral medication has been added to the list. Furthermore, the introduction of HAART has increased survival of HIV-infected patients; consequently, the frequency of HIV-associated and incidental renal disease is expected to rise in this population. Because mortality and morbidity rates are affected by the early recognition of renal disease in HIV-infected patients, it is paramount that the radiologist be familiar with the imaging features that can be encountered in such cases.

[RSNA Education Exhibits] Pearls and Pitfalls in Diagnosis of Ovarian Torsion

Chang, H. C., Bhatt, S., Dogra, V. S. — 2008-09-15

Ovarian torsion is defined as partial or complete rotation of the ovarian vascular pedicle and causes obstruction to venous outflow and arterial inflow. Ovarian torsion is usually associated with a cyst or tumor, which is typically benign; the most common is mature cystic teratoma. Ultrasonography (US) is the primary imaging modality for evaluation of ovarian torsion. US features of ovarian torsion include a unilateral enlarged ovary, uniform peripheral cystic structures, a coexistent mass within the affected ovary, free pelvic fluid, lack of arterial or venous flow, and a twisted vascular pedicle. The presence of flow at color Doppler imaging does not allow exclusion of torsion but instead suggests that the ovary may be viable, especially if flow is present centrally. Absence of flow in the twisted vascular pedicle may indicate that the ovary is not viable. The role of computed tomography (CT) has expanded, and it is increasingly used in evaluation of abdominal pain. Common CT features of ovarian torsion include an enlarged ovary, uterine deviation to the twisted side, smooth wall thickening of the twisted adnexal cystic mass, fallopian tube thickening, peripheral cystic structures, and ascites. Understanding the imaging appearance of ovarian torsion will lead to conservative, ovary-sparing treatment.

[RSNA Education Exhibits] Mucoid Impactions: Finger-in-Glove Sign and Other CT and Radiographic Features

2008-09-15

Mucoid impaction is a relatively common finding at chest radiography and computed tomography (CT). Both congenital and acquired abnormalities may cause mucoid impaction of the large airways that often manifests as tubular opacities known as the finger-in-glove sign. The congenital conditions in which this sign most often appears are segmental bronchial atresia and cystic fibrosis. The sign also may be observed in many acquired conditions, include inflammatory and infectious diseases (allergic bronchopulmonary aspergillosis, broncholithiasis, and foreign body aspiration), benign neoplastic processes (bronchial hamartoma, lipoma, and papillomatosis), and malignancies (bronchogenic carcinoma, carcinoid tumor, and metastases). To point to the correct diagnosis, the radiologist must be familiar with the key radiographic and CT features that enable differentiation among the various likely causes. CT is more useful than chest radiography for differentiating between mucoid impaction and other disease processes, such as arteriovenous malformation, and for directing further diagnostic evaluation. In addition, knowledge of the patient’s medical history, clinical symptoms and signs, and predisposing factors is important.

[RSNA Education Exhibits] Smoking-related Interstitial Lung Disease: Radiologic-Clinical-Pathologic Correlation

2008-09-15

Cigarette smoking is a recognized risk factor for development of interstitial lung disease (ILD). There is strong evidence supporting a causal role for cigarette smoking in development of respiratory bronchiolitis ILD (RB-ILD), desquamative interstitial pneumonitis (DIP), and pulmonary Langerhans cell histiocytosis (PLCH). In addition, former and current smokers may be at increased risk for developing idiopathic pulmonary fibrosis (IPF). The combination of lower lung fibrosis and upper lung emphysema is being increasingly recognized as a distinct clinical entity in smokers. High-resolution computed tomography is sensitive for detection and characterization of ILD and may allow recognition and classification of the smoking-related ILDs (SR-ILDs) into distinct individual entities. However, the clinical, radiologic, and histologic features overlap among the different SR-ILDs, and mixed patterns of disease frequently coexist in the same patient. The overlap is most significant between RB-ILD and DIP. Macrophage accumulation is bronchiolocentric in RB-ILD, producing centrilobular ground-glass opacity, and more diffuse in DIP, producing widespread ground-glass changes. The coexistence of upper lung nodules and cysts in a smoker allows confident diagnosis of PLCH. Final diagnosis of an SR-ILD and identification of the specific entity can be achieved with certainty only after the pulmonologist, radiologist, and pathologist have reviewed all of the clinical, radiologic, and pathologic data.

[RSNA Education Exhibits] Invited Commentary * Authors' Response

2008-09-15

[RSNA Education Exhibits] Rare Breast Lesions: Correlation of Imaging and Histologic Features with WHO Classification

2008-09-15

Mammographers occasionally are surprised by the diagnosis of a rare lesion at breast biopsy. The imaging features of some breast lesions are unfamiliar because they are rarely seen in routine mammographic practice and they are not well described or well documented in the radiologic literature. Moreover, there may be wide variation in the appearances of rare breast lesions at mammography and ultrasonography (US). In addition, although a few rare breast lesions have a typical imaging appearance, most have mammographic and US features similar to those of breast carcinomas, and a needle biopsy is almost always necessary to obtain a diagnosis. However, even when a rare breast lesion is diagnosed on the basis of a needle biopsy, knowledge of the imaging features of such lesions may help the radiologist decide whether the results of pathologic analysis concur with the imaging findings and whether surgical excision is necessary. It is therefore important that radiologists be familiar with the broad spectrum of imaging features of rare breast lesions as well as with the correlation between their histopathologic features and their current classification according to the World Health Organization classification system.

[RSNA Education Exhibits] Athletic Pubalgia and "Sports Hernia": Optimal MR Imaging Technique and Findings

2008-09-15

Groin injuries are common in athletes who participate in sports that require twisting at the waist, sudden and sharp changes in direction, and side-to-side ambulation. Such injuries frequently lead to debilitating pain and lost playing time, and they may be difficult to diagnose. Diagnostic confusion often arises from the complex anatomy and biomechanics of the pubic symphysis region, the large number of potential sources of groin pain, and the similarity of symptoms in athletes with different types or sites of injury. Many athletes with a diagnosis of "sports hernia" or "athletic pubalgia" have a spectrum of related pathologic conditions resulting from musculotendinous injuries and subsequent instability of the pubic symphysis without any finding of inguinal hernia at physical examination. The actual causal mechanisms of athletic pubalgia are poorly understood, and imaging studies have been deemed inadequate or unhelpful for clarification. However, a large-field-of-view magnetic resonance (MR) imaging survey of the pelvis, combined with high-resolution MR imaging of the pubic symphysis, is an excellent means of assessing various causes of athletic pubalgia, providing information about the location of injury, and delineating the severity of disease. Familiarity with the pubic anatomy and with MR imaging findings in athletic pubalgia and in other confounding causes of groin pain allows accurate imaging-based diagnoses and helps in planning treatment that targets specific pathologic conditions.

[RSNA Education Exhibits] Radiation Dose Descriptors: BERT, COD, DAP, and Other Strange Creatures

Nickoloff, E. L., Lu, Z. F., Dutta, A. K., So, J. C. — 2008-09-15

Over the years, a number of terms have been used to describe radiation dose. Eight common radiation dose descriptors include background equivalent radiation time (BERT), critical organ dose (COD), surface absorbed dose (SAD), dose area product (DAP), diagnostic acceptable reference level (DARLing), effective dose (ED), fetal absorbed dose (FAD), and total imparted energy (TIE). BERT is compared to the annual natural background radiation (about 3 mSv per year) and is easily understandable for the general public. COD refers to the radiation dose delivered to an individual critical organ. SAD is the radiation dose delivered at the skin surface. DAP is a product of the irradiated surface area multiplied by the radiation dose at the surface. DARLing is usually the radiation level that encompasses 75% (the third quartile) of the data derived from a nationwide or regional survey. DARLings are meant for voluntary guidance. Consistently higher patient doses should be investigated for possible equipment deficiencies or suboptimal protocols. ED is obtained by multiplying the radiation dose delivered to each organ by its weighting factor and then by adding those values to get the sum. It can be used to assess the risk of radiation-induced cancers and serious hereditary effects to future generations, regardless of the procedure being performed, and is the most useful radiation dose descriptor. FAD is the radiation dose delivered to the fetus, and TIE is the sum of the energy imparted to all irradiated tissue. Each of these descriptors is intended to relate radiation dose ultimately to potential biologic effects. To avoid confusion, the key is to avoid using the terms interchangeably. It is important to understand each of the radiation dose descriptors and their derivation in order to correctly evaluate radiation dose and to consult with patients concerned about the risks of radiation.

[RSNA Education Exhibits] Radiation Dose Modulation Techniques in the Multidetector CT Era: From Basics to Practice

2008-09-15

Radiation exposure to the patient has become a concern for the radiologist in the multidetector computed tomography (CT) era. With the introduction of faster multidetector CT scanners, various techniques have been developed to reduce the radiation dose to the patient; one method is automatic exposure control (AEC). AEC systems make use of different types of control, including patient-size AEC, z-axis AEC, rotational or angular AEC, or a combination of two or more of these types. AEC systems operate on the basis of several methods: standard deviation, noise index, reference milliamperage, and reference image. A clear understanding of how to use different AEC systems on different multidetector CT scanners will allow users to modulate radiation dose, reduce photon starvation artifacts, and maintain image quality throughout the body. Further development of AEC systems and their successful introduction into clinical practice will require user education and good communication between users and manufacturers.

[Letters to the Editor] Clinical Significance of High-attenuation Mucus in Patients with Allergic Bronchopulmonary Aspergillosis

Galwa, R. P., Gupta, P., Mumtaz, H. A. — 2008-09-15

[RSNA Education Exhibits] Parathyroid Scintigraphy in Patients with Primary Hyperparathyroidism: 99mTc Sestamibi SPECT and SPECT/CT

Eslamy, H. K., Ziessman, H. A. — 2008-09-15

The clinical diagnosis of primary hyperparathyroidism is based largely on serum laboratory test results, as patients often are asymptomatic. Surgery, often with bilateral exploration of the neck, has been considered the definitive treatment for symptomatic disease. However, given that approximately 90% of cases are due to a single parathyroid adenoma, a better treatment may be the selective surgical excision of the hyperfunctioning parathyroid gland after its preoperative identification and localization at radiologic imaging. Scintigraphy and ultrasonography are the imaging modalities most often used for preoperative localization. Various scintigraphic protocols may be used in the clinical setting: Single-phase dual-isotope subtraction imaging, dual-phase single-isotope imaging, or a combination of the two may be used to obtain planar or tomographic views. Single photon emission computed tomography (SPECT) with the use of technetium-99m (^99mTc) sestamibi as the radiotracer, especially when combined with x-ray–based computed tomography (CT), is particularly helpful for preoperative localization: The three-dimensional functional information from SPECT is fused with the anatomic information obtained from CT. In addition, knowledge of the anatomy and embryologic development of the parathyroid glands and the pathophysiology of primary hyperparathyroidism aid in the identification and localization of hyperfunctioning glands.

[Special Exhibits] Scenes from the Past: Common and Unexpected Findings in Mummies from Ancient Egypt and South America as Revealed by CT

Jackowski, C., Bolliger, S., Thali, M. J — 2008-09-15

Computed tomography (CT) has proved to be a valuable investigative tool for mummy research and is the method of choice for examining mummies. It allows for noninvasive insight, especially with virtual endoscopy, which reveals detailed information about the mummy’s sex, age, constitution, injuries, health, and mummification techniques used. CT also supplies three-dimensional information about the scanned object. Mummification processes can be summarized as "artificial," when the procedure was performed on a body with the aim of preservation, or as "natural," when the body’s natural environment resulted in preservation. The purpose of artificial mummification was to preserve that person’s morphologic features by delaying or arresting the decay of the body. The ancient Egyptians are most famous for this. Their use of evisceration followed by desiccation with natron (a compound of sodium salts) to halt putrefaction and prevent rehydration was so effective that their embalmed bodies have survived for nearly 4500 years. First, the body was cleaned with a natron solution; then internal organs were removed through the cribriform plate and abdomen. The most important, and probably the most lengthy, phase was desiccation. After the body was dehydrated, the body cavities were rinsed and packed to restore the body’s former shape. Finally, the body was wrapped. Animals were also mummified to provide food for the deceased, to accompany the deceased as pets, because they were seen as corporal manifestations of deities, and as votive offerings. Artificial mummification was performed on every continent, especially in South and Central America.

[AFIP Archives] From the Archives of the AFIP: Pigmented Villonodular Synovitis: Radiologic-Pathologic Correlation

2008-09-15

Pigmented villonodular synovitis (PVNS) represents an uncommon benign neoplastic process that may involve the synovium of the joint diffusely or focally (PVNS) or that may occur extraarticularly in a bursa (pigmented villonodular bursitis [PVNB]) or tendon sheath (pigmented villonodular tenosynovitis [PVNTS]). Pathologic specimens of the hypertrophic synovium may appear villous, nodular, or villonodular, and hemosiderin deposition, often prominent, is seen in most cases. The knee, followed by the hip, is the most common location for PVNS or PVNB, whereas PVNTS occurs most often in the hand and foot. PVNTS is also referred to as giant cell tumor of the tendon sheath (GCTTS). PVNTS is the most common form of this disease by a ratio of approximately 3:1. Radiographs reveal nonspecific features of a joint effusion in PVNS, a focal soft-tissue mass in PVNB or PVNTS, or a normal appearance. Extrinsic erosion of bone (on both sides of the joint) may also be seen and is most frequent with intraarticular involvement of the hip (>90% of cases). Cross-sectional imaging reveals diffuse involvement of the synovium (PVNS), an intimate relationship to the tendon (PVTNS), or a typical bursal location (PVNB), findings that suggest the diagnosis. However, the magnetic resonance (MR) imaging findings of prominent low signal intensity (seen with T2-weighting) and "blooming" artifact from the hemosiderin (seen with gradient-echo sequences) are nearly pathognomonic of this diagnosis. In addition, MR imaging is optimal for evaluating lesion extent. This information is crucial to guide treatment and to achieve complete surgical resection. Recurrence is more common with diffuse intraarticular disease and is difficult to distinguish, both pathologically and radiologically, from the rare complication of malignant PVNS. Recognizing the appearances of the various types of PVNS, which reflect their pathologic characteristics, improves radiologic assessment and is important for optimal patient management.

[AFIP Archives] Best Cases from the AFIP: Pigmented Villonodular Synovitis

Garner, H. W., Ortiguera, C. J., Nakhleh, R. E — 2008-09-15

[AFIP Archives] Best Cases from the AFIP: Appendiceal Mucinous Cystadenoma

Honnef, I., Moschopulos, M., Roeren, T. — 2008-09-15