摘要:

Congenital heart disease (CHD) is a major clinical problem in children, occurring in 0.8% of newborns (1). In the past, most patients with CHD died in infancy. With improved surgical and postoperative care, as well as more accurate preoperative evaluation, the overall 10-year survival rate is >90%. As a result, >500,000 adults in the United States have surgically treated CHD (2). In addition, at least 150,000 adults are thought to have unrecognized, misdiagnosed, or recognized but untreated CHD (3,4). Diagnostic imaging procedures for the evaluation of CHD include plain film radiology, fluoroscopy, angiocardiography, echocardiography, scintigraphy, computed tomography (CT), and magnetic resonance imaging (MRI). Each has unique as well as overlapping abilities to characterize precisely cardiovascular anatomy and pathophysiology. We emphasize those congenital cardiac disorders found predominantly in adults. In addition, conditions that are usually unrecognized in childhood, “slip through the system”, and become clinically recognized in adults for the first time, often with an atypical clinical presentation, are discussed (5). The interpreter of the plain film radiograph has a unique opportunity to identify and often characterize the severity of a congenital cardiac disorder that may be unrecognized by the patient's physician. Important clues found on plain film radiographs will suggest either additional studies to pinpoint the type of CHD more precisely or that no additional studies are needed because the recognized lesion is incidental and not of clinical significance.

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Tetralogy of Fallot was invariably fatal until the development of palliative and later corrective surgical procedures. The prognosis for children with tetralogy of Fallot continues to improve almost a half century after the earliest palliative surgical procedure was performed successfully. Imaging of the child and adult after surgery for tetralogy of Fallot remains an important challenge because surgical complications or limitations frequently require imaging for complete evaluation and further management of the patient. Traditional imaging by chest radiography and arteriography has been largely replaced by echocardiography and ultrafast and conventional CT, as well as magnetic resonance imaging. This article reviews those aspects of diagnostic imaging that are appropriate to study the postoperative chest in the child or adult with tetralogy of Fallot.

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The clinical evaluation and management of the patient with coarctation of the aorta continues to evolve. Traditional imaging evaluation by plain film chest radiography, barium esophagography, and arteriography with pressure measurements across the coarctation has been largely supplanted by Doppler echocardiography and magnetic resonance imaging (MRI). The complications of surgery and balloon angioplasty, including residual or recurrent coarctation and aneurysm, can also be evaluated noninvasively by echocardiography and MRI. Chest radiography continues to play an important role in “first discovery” imaging in asymptomatic patients.

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

(Definitions) Situs solitus indicates the normal position of the cardiac atria and viscera. Situs solitus with levocardia is the normal situation, with <1% incidence of congenital heart disease (Table 1). Levocardia denotes a left-sided heart and a left cardiac apex; it does not give any indication of cardiac structure or body situs (Fig. 1A). Situs inversus is the mirror-image location of the atria and abdominal viscera (Fig. 1B). Heterotaxia is the abnormal arrangement of organs and major blood vessels different from the orderly arrangement of either situs solitus or situs inversus. In situs ambiguus or heterotaxia, the relationship of the atria and viscera is inconsistent. Isomerism, a form of heterotaxia, is a term used to describe symmetric morphology, i.e., both sides of the viscera, and both lungs are nearly identical to one another (Fig. 2). Right isomerism or asplenia syndrome is characterized by situs ambiguus with bilateral right-sidedness (Fig. 2A). Left isomerism or polysplenia syndrome is a second type of situs ambiguus characterized by bilateral left-sidedness (Fig. 2B). In this review, all patients having situs ambiguus with either right isomerism (asplenia syndrome) or left isomerism (polysplenia syndrome) are regarded as having cardiac malposition, an inappropriate cardiac position.

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

We compared the conspicuity of acute pulmonary emboli with contrast-enhanced spiral computed tomography (CT) and two- and three-dimensional time-of-flight magnetic resonance (MR) techniques. Seven dogs who received experimental pulmonary emboli and one control were imaged with spiral CT and with 2-D (FMPVAS and FASTCARD) and 3-D time-of-flight MR. Blinded, independent, prospective evaluations of the CT and MR images by two MR radiologists and two chest radiologists were then compared to the location of the emboli as determined by subsequent pathologic evaluation of the excised lungs. Embolus/blood contrast-to-noise ratios (CNRs) were calculated on both MR and CT images for pulmonary emboli that could be identified. Fifty emboli ranging from 1.0 to 5.5 mm (mean, 2.7, ±0.14 SEM) in diameter and from 3.0 to 60 mm (mean, 28.1, ±1.9 SEM) in length were found in the seven embolized dogs on pathologic examination. Three of the four radiologists identified more thrombi on CT images than they did on their best MR pulse sequence (FASTCARD) and with greater confidence. The fourth radiologist identified an equal percentage of clot on CT and FASTCARD images with confidence slightly greater on FASTCARD MR than on spiral CT. Mean CNR for the best MR technique was 43.4 (±3.9 SEM) and for CT was 20.7 (± 1.3 SEM). In general, pulmonary emboli were detected more accurately on contrast-enhanced spiral CT than on MR. This occurred although the embolus/blood CNR was higher on MR than on CT. Better pulmonary embolus conspicuity on CT images was attributed to better spatial resolution and fewer artifacts on CT than on MR. One MR radiologist performed equally well with both spiral CT and FASTCARD techniques, suggesting that experience may be a factor in performance.

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The aim of this study was to develop a magnetic resonance (MR) sequence capable of measuring water content and the gravity-dependent gradient in lung density in normal lung. First, the MR signal from excised normal pig lung was characterized using a 2.1 T nuclear magnetic resonance (NMR) spectrometer. A multiecho sequence was then developed on a 0.15 T Picker MR scanner. This sequence was validated in excised normal pig lung by comparison with gravimetric lung water content. Finally, this sequence was used in five normal volunteers in the prone and supine positions during quiet breathing and in the supine position at total lung capacity (TLC). The ratio of lung water measured by MR and gravimetric techniques was 0.95 ± 0.03. There was no significant difference in average lung density in the prone (0.21 ± 0.03 g/ml) and in the supine (0.20 ± 0.03 g/ml) positions. Lung density decreased at TLC (0.12 ± 0.01 g/ml) (p < 0.01). Gradients in lung density were visible in all prone and supine scans at functional residual capacity (FRC), and on average the gradients were decreased by 90% at TLC. The average estimated pleural pressure gradient in the prone position was 0.13 ± 0.08 cm H2O/cm lung and in the supine position was 0.38 ± 0.23 cm H2O/cm lung. MRI allows measurement of lung water content and pleural pressure gradient.

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Non-Hodgkin lymphoma (NHL) rarely arises from tuberculous empyema. We report a case in which magnetic resonance (MR) imaging was useful in separating the lymphoma from the chronic empyema.

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0883-5993    

出版商:OVID    

年代:1995

数据来源: OVID