Chronic radiographic lung changes in children with vertically transmitted HIV-1 infection.

OBJECTIVE: We prospectively studied children with and without maternally transmitted HIV-1 infection born to mothers infected with HIV-1 to determine the incidence of chronic radiographic lung changes (CRC) and to correlate these changes with clinical assessments. SUBJECTS AND METHODS: Between 1990 and 1997, we scored 3050 chest radiographs using a standardized form. Group I children (n = 201) were HIV-1-infected at enrollment. Group II children (n = 512) were enrolled prenatally or before 28 days postpartum and subsequently subdivided into group IIa (n = 86), children identified as HIV-1-infected; and group IIb (n = 426), those who were HIV-1-uninfected. CRC were defined as parenchymal consolidations or nodular disease lasting 3 months or more or increased bronchovascular markings or reticular densities lasting 6 months or more. Morbidity was assessed by CD4 counts, viral load, the presence of low oxygen saturation, wheezing, tachypnea, crackles, and clubbing. RESULTS: The cumulative incidence of chronic radiographic lung changes in HIV-1-infected children was 32.8% by 4 years old, with increased bronchovascular markings or reticular densities being most common. Chronic changes were associated with lower CD4 cell counts and higher viral loads. Resolution of these chronic changes was associated with decreasing CD4 cell counts but not with lower rates of clinical findings, viral load, or difference in survival. CONCLUSION: With increased survival, CRC are becoming more common. The resolution of these changes may indicate immunologic deterioration rather than clinical improvement.

Estimated risks of radiation-induced fatal cancer from pediatric CT.

OBJECTIVE: In light of the rapidly increasing frequency of pediatric CT examinations, the purpose of our study was to assess the lifetime cancer mortality risks attributable to radiation from pediatric CT. MATERIALS AND METHODS: Organ doses as a function of age-at-diagnosis were estimated for common CT examinations, and estimated attributable lifetime cancer mortality risks (per unit dose) for different organ sites were applied. Standard models that assume a linear extrapolation of risks from intermediate to low doses were applied. On the basis of current standard practice, the same exposures (milliampere-seconds) were assumed, independent of age. RESULTS: The larger doses and increased lifetime radiation risks in children produce a sharp increase, relative to adults, in estimated risk from CT. Estimated lifetime cancer mortality risks attributable to the radiation exposure from a CT in a 1-year-old are 0.18% (abdominal) and 0.07% (head)-an order of magnitude higher than for adults-although those figures still represent a small increase in cancer mortality over the natrual background rate. In the United States, of approximately 600,000 abdominal and head CT examinations annually performed in children under the age of 15 years, a rough estimate is that 500 of these individuals might ultimately die from cancer attributable to the CT radiation. CONCLUSION: The best available risk estimates suggest that pediatric CT will result in significantly increased lifetime radiation risk over adult CT, both because of the increased dose per milliampere-second, and the increased lifetime risk per unit dose. Lower milliampere-second settings can be used for children without significant loss of information. Although the risk-benefit balance is still strongly tilted toward benefit, because the frequency of pediatric CT examinations is rapidly increasing, estimates that quantitative lifetime radiation risks for children undergoing CT are not negligible may stimulate more active reduction of CT exposure settings in pediatric patients.

Rings, slings, and other things: vascular compression of the infant trachea updated from the midcentury to the millennium--the legacy of Robert E. Gross, MD, and Edward B. D. Neuhauser, MD.

In the first half of the 20th century, pediatric chest imaging was limited mainly to the performance of conventional radiography, including barium esophagography and occasionally bronchography and angiography. Despite this limited imaging approach, by 1950 the diagnosis and treatment of vascular "rings" compressing infant airways had been accomplished with the pioneering efforts of Robert E. Gross, MD, in the field of surgery, and Edward B. D. Neuhauser, MD, in the field of radiology. The next two decades brought the recognition of pulmonary arterial "sling," or anomalous left pulmonary artery, in diagnosis and treatment. Recognition of still another vascular compressive syndrome in infants was identified as that due to the absence of the pulmonary valve. These "rings, slings, and other things" are now evaluated with magnetic resonance (MR) imaging, including MR angiography, and computed tomography (CT), including CT angiography, with the added use of three-dimensional reconstruction. These are the legacies of Drs Gross and Neuhauser.

Imaging features of Mycobacterium avium-intracellulare complex (MAC) in children with AIDS.

PURPOSE: The purpose of this paper was to review the imaging features of Mycobacterium avium-intracellulare complex (MAC) in 16 pediatric patients with human immunodeficiency virus (HIV). MATERIALS AND METHODS: We reviewed the pertinent clinical records of 16 children diagnosed with MAC between January 1990 and June 1998. These 16 cases were blood- or biopsy-proven to have MAC infection. Their plain films, abdominal, and chest CT scans were then reviewed and the findings were analyzed with reference to the few reported cases of children with MAC. RESULTS: Abdominal findings: all but one had retroperitoneal adenopathy, mesenteric adenopathy or both. Ten patients had hepatomegaly, while nine patients were found to have splenomegaly. Four patients had nonspecific thickened gallbladder wall, while intestinal wall thickening and thickened stomach folds were identified in six of ten patients. Necrotic, fluid-filled nodes were also found. Chest findings included mediastinal adenopathy, cystic/cavitary lesions and bronchiectasis. One patient developed a fistula between the mediastinal lymph nodes, esophagus, and bronchial tree. CONCLUSION: Pediatric patients with HIV who develop MAC infection may present with massive lymph node enlargement. This can occur not only in mesenteric and retroperitoneal nodes but also in hilar and posterior mediastinal nodes as well. As in MTB infection, these nodes can break down with development of fistulous tracts to both esophagus and adjacent lung. The major differential diagnostic consideration besides MTB is lymphoma.

Osteoporosis: an unusual presentation of childhood Crohn's disease.

Osteoporosis is known to be associated with Crohn's disease. We report a 12-yr-old boy without a history of steroid use, in whom severe osteoporosis and multiple collapsed vertebrae were the presenting manifestations of Crohn's disease. After treatment of the Crohn's disease, he resumed normal growth and progressed through puberty. Concomitantly, he demonstrated a substantial recovery of vertebral bone mineral density and structure. Possible pathophysiological mechanisms underlying the osteoporosis and the subsequent improvement in bone density are discussed.

Hepatic pulmonary fusion in neonates.

OBJECTIVE: This report discusses the relationship of supradiaphragmatic hepatic tissue that is fused to the lung (through a diaphragmatic defect) with pulmonary hypoplasia-a new constellation of findings. CONCLUSION: Hepatic pulmonary fusion should be suspected in instances of apparent diaphragmatic hernia characterized by mediastinal shift towards the hypoplastic lung or when the mediastinum does not shift away from the mass.

CT imaging of splenic sequestration in sickle cell disease.

Pooling of blood in the spleen is a frequent occurrence in children with sickle cell diseases, particularly in the first few years of life, resulting in what is termed "splenic sequestration crisis." The spectrum of severity in this syndrome is wide, ranging from mild splenomegaly to massive enlargement, circulatory collapse, and even death. The diagnosis is usually clinical, based on the enlargement of the spleen with a drop in hemoglobin level by > 2 g/dl, and it is rare that imaging studies are ordered. However, in the patient who presents to the emergency department with non-specific findings of an acute abdomen, it is important to recognize the appearance of sequestration on imaging studies. We studied seven patients utilizing contrast-enhanced CT scans and found two distinct patterns--multiple, peripheral, non-enhancing low-density areas or large, diffuse areas of low density in the majority of the splenic tissue. Although radiological imaging is not always necessary to diagnose splenic sequestration, in those situations where this diagnosis is not immediately obvious, it makes an important clarifying contribution.

Punctate thymic calcification in infants with untreated Langerhans' cell histiocytosis: report of four new cases.

Four new cases of punctate thymic calcification in infants with untreated Langerhans' cell histiocytosis (LCH) are added to the four previously reported cases. All cases were shown on CT scans; plain films were rarely diagnostic. Pathologic correlation remains elusive since the usual biopsies of the LCH have been on skin or bone biopsies. A single prior pathologic study of the thymus in untreated LCH showed microscopic calcospherites. The thymic punctate calcific densities in patients with LCH may represent further accretion so that the calcospherites become macroscopic. The finding of such punctate calcific densities in an enlarged thymus of an infant with skin or bone or lung disease is strongly suggestive of LCH.

Neuroblastoma arising from the organ of Zuckerkandl: an unusual site with a favorable biologic outcome.

BACKGROUND: Prognosis in neuroblastoma has been shown to correlate with age and stage at diagnosis and site of origin. Extra-abdominal tumors (chest, neck, pelvis) do better in terms of survival than tumors arising from the upper abdomen. OBJECTIVE: We evaluated a subgroup of abdominal neuroblastomas arising near to the aortic bifurcation (commonly called organ of Zuckerkandl, O. Z.) to assess their biologic outcome and problems in diagnosis and therapy. MATERIALS AND METHODS: Sixteen O. Z. primary tumors were seen at three children's hospitals. Their clinical records and imaging studies were reviewed, including the sonographic, CT, and MRI findings. When available, MYCN amplification was noted (MYCN is the current term previously called N-MYC). RESULTS: Despite more than half of the tumors being very large, survival was the rule, with only one fatality (following multiple local recurrences). Only one patient (who survived) had bone metastases. The larger masses were usually palpated in otherwise well children, while the smaller ones were found in the course of evaluation for unrelated problems such as urinary tract infection. Intraspinal extension was common, though usually asymptomatic. MYCN amplification was absent in the four patients studied. CONCLUSIONS: Lower abdominal (O. Z.) neuroblastomas present technical problems of surgical removal, but form a group with a favorable outcome similar to cervical and thoracic primary sites. MRI was useful in delineating intraspinal extension.

Malignancies in pediatric patients with ataxia telangiectasia.

BACKGROUND: Patients with ataxia telangiectasia (AT), known to have an inherent increased susceptibility to the development of cancer, may present with malignancies that are unusual for the patient's age, are often difficult to diagnose clinically and radiographically and respond poorly to conventional therapy. MATERIALS AND METHODS: We reviewed the clinical presentation and imaging studies of 12 AT patients who developed malignancies. RESULTS: Eight of the twelve patients developed non-Hodgkin's lymphoma (CNS, thorax, bone), two developed Hodgkin's disease, and two were diagnosed with gastrointestinal mucinous adenocarcinoma. CONCLUSION: The lymphomas were commonly extra nodal, and infiltrative rather than mass-like. The recognition of the tumors was often delayed due to confusion with the known infectious complications in AT patients.