An approach for the estimation of effective radiation dose at CT in pediatric patients.

PURPOSE: To estimate the effective radiation dose to pediatric and adult patients at head and abdomen computed tomography (CT). MATERIALS AND METHODS: Cylindrical water-equivalent phantoms were modeled for patients aged newborn to adult, and the energy imparted per unit axial exposure was computed. To determine the energy imparted to the simulated patients of different ages undergoing head and abdomen CT examinations, x-ray technique factors were combined with measured CT axial exposures. Body-region-specific ratios were calculated for effective dose per unit energy imparted, and these ratios were corrected for patient mass to obtain the effective dose to simulated patients. RESULTS: With use of standard techniques, the energy imparted to simulated patients at CT always increased with patient size, but the effective dose was higher in children than in adults. At CT in the head and abdomen, effective doses were highest in newborns. Effective doses ranged from 1.5 to 6.0 mSv in head CT examinations and from 3.1 to 5.3 mSv in abdomen CT examinations. CONCLUSION: The values for energy imparted at CT in pediatric patients were generally lower than in adults. The smaller mass of children, however, caused the corresponding effective doses to be higher than those in adults undergoing similar CT examinations.

Supraglottic airway infections.

Supraglottic infections are included among the more serious pediatric infections, although they are less common than other pediatric respiratory infections. Supraglottic infections include epiglottis (supraglottitis), retropharyngeal cellulitis, retropharyngeal abscess, and peritonsillar abscess. A high index of suspicion combined with rapid diagnosis and treatment are crucial to reducing the morbidity and mortality associated with these infections. A review of these infections, including diagnosis and treatment, is presented.

Neonatal gastrointestinal imaging.

As an aid to practicing neonatologists, the many gastrointestinal anomalies and diseases found in neonates are discussed with regard to choosing the most efficient and appropriate imaging modalities in each. The discussion is organized under anatomical headings: esophagus, stomach, small bowel, colon, liver, and miscellaneous. Nine representative images are included as illustrations. There is a brief discussion of umbilical arterial and venous catheters.

Mottle on computed radiographs of the chest in pediatric patients.

PURPOSE: To investigate the relationship between radiation exposure and perceived mottle at bedside pediatric chest examinations performed with screen-film and computed radiographic techniques. MATERIALS AND METHODS: In a pediatric intensive care unit, chest radiographs were obtained with both computed radiography (60 radiographs) and a 600-speed screen-film system (14 radiographs). The relative radiation exposure was estimated by using the sensitivity value obtained in the processing of each computed radiograph. Five radiologists assessed the mottle present in the computed radiographs and screen-film images. RESULTS: For computed radiographs, the perceived level of mottle was inversely related to radiation exposure. For the same radiation exposure, the perceived mottle on computed radiographs was significantly higher than that on screen-film images (P < .001 for small cassettes; P < .01 for large cassettes). CONCLUSION: Pediatric computed radiography of the chest requires approximately twice the exposure of a 600-speed screen-film system to attain the same level of mottle.

Posterior hepatodiaphragmatic interposition of the colon complicated by appendicitis.

Posterior hepatodiaphragmatic interposition is a rare malposition of the cecum that persists over time but is usually of little or no clinical importance. However, when inflammation occurs in the appendix, the symptoms and signs are those of subphrenic disease rather than abdominal disease and may be misleading to the attending physicians. Radiologists should report the presence of anterior and posterior hepatodiaphragmatic interposition and should differentiate between the two.

Accidental catheterization of internal iliac artery branches: a serious complication of umbilical artery catheterization.

Umbilical artery catheters can accidentally enter branches of the internal iliac artery during attempted placement in the aorta. The three branches likely to be catheterized are the superior gluteal, inferior gluteal, and internal pudendal arteries. If these misplacements are not recognized and promptly corrected, arterial obstruction may lead to ischemia and infarction of the iliac bone, gluteal muscles, sciatic nerve, perineum, and overlying skin. We present three patients who suffered long-term consequences of umbilical artery catheter misplacements and discuss the radiographic verification of catheter placement that is essential before infusing medications.

Torsion of the spleen: an unusual presentation of congenital diaphragmatic hernia.

We describe an unusual case of congenital diaphragmatic hernia in a 6-week-old boy who presented with severe respiratory distress due to torsion of the spleen which had passed up into the chest through a Bochdalek hernia and caused a left hemothorax. Scintigraphy with heat-damaged red cells was diagnostic by showing a damaged but functioning spleen above the diaphragm. Surgical repair and return of the spleen to the abdomen resulted in complete recovery.

Severe hyperphosphatemia associated with tumor lysis in a patient with T-cell leukemia.

Hyperphosphatemia is an infrequent complication of the tumor lysis following induction therapy for lymphoproliferative disorders that can result in acute renal failure. We report a case of severe hyperphosphatemia resulting in transient acute renal failure corrected rapidly by hemodialysis.

Ductus arteriosus aneurysm: an unusual mediastinal mass.

The following is a case report of a ductus arteriosus aneurysm in a newborn. Its various appearance on different imaging modalities, including chest x-ray, computed tomography scan, magnetic resonance imaging, and angiography, are demonstrated. The differential diagnosis of this mediastinal mass, complications related to ductus aneurysms and the appropriate radiographic workup are discussed.

Pneumatic reduction of ileocolic intussusception in children.

Pneumatic reduction of ileocolic intussusception in children has been used in Argentina and in China for more than 25 years but has only recently been attempted in North America. It is reported to be safer and more effective than reduction by the hydrostatic pressure of a barium suspension. Our preliminary experience with four patients has been rewarding and we believe it may become the method of choice.

Campomelia, cervical lymphocele, polycystic dysplasia, short gut, polysplenia.

An aborted fetus, the offspring of consanguineous parents, had the unusual combination of campomelia, cervical lymphocele, polycystic kidneys, pancreas, and liver, short gut, and polysplenia. Births of earlier similarly affected fetuses suggest an autosomal recessive inheritance. Skeletal, lymphatic, and renal lesions were seen at 26 weeks' gestation by ultrasonography, but not at 16 weeks.

Bronchopulmonary dysplasia.

Neonatal pulmonary diseases may require mechanical ventilation and supplemental oxygen therapy. These supportive measures can damage the immature lung or distort the normal maturation processes of the developing lung. The formation of hyaline membranes occurs acutely, often complicated by left-to-right cardiac shunts. Pulmonary edema occurs next, followed by interstitial fibrosis and finally by parenchymal emphysema. This process is termed bronchopulmonary dysplasia. Significant morbidity and mortality are associated with this developmental pulmonary dysplasia, particularly during the first two years of life. A delay in normal growth and development is often present, acute episodes of pulmonary insufficiency are seen, and multiple episodes of pulmonary infection occur. Subsequently, the radiographic appearance and the clinical symptoms improve. Therapy is mainly supportive throughout the course of the disease and the bronchopulmonary dysplasia tends to resolve slowly. Residual pulmonary dysfunction is usually mild or absent.

Carbonic anhydrase II deficiency syndrome: recessive osteopetrosis with renal tubular acidosis and cerebral calcification.

Four new Saudi Arabian cases of the carbonic anhydrase II deficiency syndrome from two families are described. This autosomal recessive syndrome includes osteopetrosis with renal tubular acidosis and cerebral calcification. Additional features are mental retardation, growth failure, typical facial appearance, and abnormal teeth. Two patients showed evidence of restrictive lung disease, a finding not previously described. One of the patients reported represents the first neonate reported to be affected with this syndrome. Intrauterine growth was normal, but metabolic acidosis was already evident in the neonatal period. Radiographic evidence of osteopetrosis was probably absent at birth but appeared during the late neonatal period. Carbonic anhydrase II deficiency was demonstrated in erythrocyte hemolysates from the older two siblings of this neonate, and a 50% normal level of carbonic anhydrase II was demonstrated in the erythrocyte hemolysate from their father.

Candidiasis in very low birthweight infants. Ultrasonography in the diagnosis of renal involvement.

Systemic candidiasis is a serious infection in very low birthweight infants. Its diagnosis is difficult to make and is often missed. Renal involvement may be diagnostic, consisting of mechanical obstruction by fungus masses in the renal pelvis. A case is presented which demonstrates the importance of carrying out multiple ultrasonographic examinations of patients at risk.