Radiology of AIDS in the pediatric patient.

The Acquired Immunodeficiency Syndrome (AIDS) has involved the pediatric age group and is especially prevalent in babies born of mothers who are intravenous drug abusers or prostitutes. Approximately 30% of children born to mothers who are seropositive for the human immunodeficiency virus (HIV) will develop HIV infection. There are several important differences in children and adults with AIDS. The incubation period of the disease is shorter, and initial clinical manifestations occur earlier in children. In addition, certain infections are more common in children, and the different types of malignancy, especially Kaposi's sarcoma, are unusual in the pediatric age group. The altered immune system involves both T cells and humoral immunity and increases susceptibility to a variety of infections, particularly opportunistic organisms. In this publication the complications of pediatric AIDS involving the lungs, cardiovascular system, gastrointestinal tract, genitourinary system, and neurological system are described. The most common pulmonary complications in our experience are Pneumocystis carinii pneumonia and pulmonary lymphoid hyperplasia. The spectrum of cardiovascular involvement in pediatric AIDS includes myocarditis, pericarditis, and infectious endocarditis. Gastrointestinal tract involvement is usually due to opportunistic organisms that produce esophagitis, gastritis, and colitis. Abdominal lymphadenopathy is a common finding either due to disseminating Mycobacterium avium-intracellulare infection or nonspecific lymphadenopathy. Although cholangitis is more commonly seen in adults, it may occur in children with AIDS and, in most cases, is due to related opportunistic infections. Genitourinary infections may be the first evidence of HIV disease. Cystitis, pyelonephritis, renal abscesses, and nephropathy with renal insufficiency are complications of pediatric AIDS. A variety of neurological abnormalities may occur in pediatric AIDS. The most common cause of neurological dysfunction in children with AIDS is HIV neuropathy. We present the many complications of AIDS in children demonstrated by a variety of imaging modalities, emphasizing the importance of diagnostic imaging in children with this disease.

The many faces of neuroblastoma.

Neuroblastoma is a common tumor in childhood. It arises in the adrenal gland or in various extraadrenal primary sites of the sympathetic chain. Clinically, it may present as an abdominal mass or as disseminated metastatic disease. We studied 52 patients with neuroblastoma, and the typical and unusual radiographic features of the disease are presented.

Use of low osmolar contrast for gastrointestinal studies in low-birth-weight infants.

Metrizamide is a safe, water-soluble contrast medium suitable for bedside gastrointestinal studies in low-birth-weight infants. We describe our experience with 26 patients and 34 examinations. We present illustrative cases and indicate the clinical applications. Similar results are anticipated when less expensive nonionic contrast agents are approved by the Food and Drug Administration for pediatric use.

Computerized tomography demonstration of an intrarenal teratoma.

The computerized tomographic appearance of an intrarenal teratoma is described. The differential diagnoses, especially from Wilms tumor, are discussed.

Intentional and unintentional abuse of infants and children.

Intentional abuse of an infant is usually apparent. External injuries such as burns, bites, and bruises, as well as the skeletal changes of fractures, frequently multiple and in various stages of healing, are obviously intentionally inflicted, and are impossible accidental injuries for the nonambulatory young infant. Similar injuries in young children may be more difficult to evaluate because of their fear of and intimidation by the person who inflicted the injury. Fortunately, the high degree of suspicion regarding the nature of the injury permits the physician to make his accusations with legal protection in our judicial system. Every radiologist should be concerned with the responsibility of reporting to the referring physician the possibility of intentional trauma to infants and children. In Harris County, where Houston is located, there are 1,500 reports per month of child abuse; in other words, this approximates 18,000 cases a year in our community, and the radiologist is frequently the first physician to see evidence of the abused child. Not only is it a moral responsibility for the radiologist to report his suspicions, but in the state of Texas, as in other states, "any person having cause to believe that a child's physical and mental health, or welfare has been or may be adversely affected by abuse or neglect shall report" to the appropriate agency. A more recent amendment to this law is a penalty for failure to report. A person commits an offense if the person has cause to believe that a child's physical and mental health or welfare has been or may be adversely affected further by abuse or neglect and knowingly fails to report it. It is hoped that any radiologist recognizing either pathognomonic or suspicious signs of child abuse will have the conscience and courage to take a strong stand for the protection of the abused infant or child. Accidental injuries in older children may offer problems in diagnosis if there is no history available or if there is a denial of an injury. Some of these injuries may produce radiographic findings suggesting some form of metaphyseal or diaphyseal dysplasia. Iatrogenic injuries are frequently the result of physiologic or anatomical response to proper and lifesaving treatment. The most serious of these are found in the premature infant, who may suffer chronic lung disease or, more seriously, brain damage.(ABSTRACT TRUNCATED AT 400 WORDS)

The use of digital subtraction angiography in evaluating pulmonary abnormalities in children.

In nine cases of pulmonary lesions in children, the diagnostic procedure of digital subtraction angiography was used with minimal invasiveness. Vascular anatomy was additionally confirmed by angiocardiography in four cases. One patient had a thoracotomy with removal of a nonvascular mass, whereas the other four patients, based on information provided by the digital subtraction angiogram, continued to be followed clinically. Using a peripheral vein for injection, intravenous subtraction angiography proved to be a satisfactory method of evaluating pulmonary vascular lesions and provided considerable information. Although other imaging modalities, including angiocardiography, computerized axial tomography scanning, or radionuclide studies, may be necessary for confirmation of the diagnosis, digital subtraction angiography should be considered in the work-up of pulmonary abnormalities in the pediatric patient. Five of the nine case studies are presented as appropriate examples.

Digital subtraction angiography in children.

Preliminary results with digital subtraction angiography in infants and children have shown this to be an excellent screening procedure and often diagnostic. The examination can be performed satisfactorily on outpatients. Sixty patients have undergone this examination for evaluation of suspected abnormalities of the aortic arch and its branches, intracranial arteries, pulmonary arteries, abdominal aorta and its branches, and peripheral vessels. Adequate sedation is mandatory to prevent motion artifacts. While the literature reports increasing use of central venous catheters for delivery of contrast material, the use of short catheters placed in an antecubital vein is satisfactory for the pediatric patient. Techniques of the procedures are described along with seven appropriate case examples.

Optical constants in the IR from thin film interference and reflectance: the reststrahlen region of muscovite mica.

A new technique for determining the IR optical constants of materials that can be formed into thin films is presented. At a given wavelength the thickness of the film t, the index of refraction n, and the extinction coefficient k combine to produce interference effects in the film, which in turn control reflectance from the film. When reflectance is plotted vs thickness the resultant curve is a unique function of n and k. Values of n and k are determined by curve fitting. The technique is illustrated using thin films of muscovite mica, and values of n and k are reported for wave numbers from 1200 to 400 cm-1, which include the reststrahlen region of mica.

Infrared thermography: a graphic interpretation of exitance as a function of surface temperature, emittance, and background.

Calorimetrio and radiation balance equations for an object in thermal equilibrium with its environment are combined to yield a graphic interpretation of exitance as a function of surface temperature, emittance, and background factors. In a monochromatic image of a scene, errors in interpreting the same shade-of-gray as being isothermal are immediately apparent from the graph. Relative effects on exitance of fractional changes in the experimental variables, internal power dissipation through the surface and emittance of the surface are derived and illustrated graphically. Modifications of the simple model move toward real world imagery.

Computed tomography in the evaluation of chest lesions in the pediatric patient.

The role of computed tomography (CT) in the management of chest masses in the pediatric patient is emphasized and illustrated. Thirty-seven patients with various chest lesions who had both CT and conventional radiologic evaluations are reviewed. CT was the most consistently accurate examination, especially in the evaluation of disease extent and relationship with other organs. CT was the only modality to provide clinically useful information in 27% of the cases, and it provided significant additional information in another 24% of the group.

Radiologic considerations of intensive care in the premature infant. Annual oration in honor of William Henry Neil, M.D., 1924-1972.

Radiology of the premature infant is a relatively new specialty in medicine. Most complications of intensive care in the premature infant are radiologically recognizable, and therefore are frequently first detected by the radiologist. Complications of umbilical catheterization and of pulmonary and cardiovascular systems, alimentary tract, skeletal system, and central nervous system are considered. Radiation exposure and cost of intensive care are also discussed.