Dose and image quality optimization in neonatal radiography.

In a special care baby unit, neonates, mainly premature, encounter serious to life-threatening diseases, the timely diagnosis and treatment of which may require a large number of radiographs. Increased neonatal radiosensitivity and longer life expectancy increase the risk of radiation-induced cancer, which emphasizes the importance of minimizing dose while maintaining clinically satisfactory image quality. An optimization study on radiation dose and image quality in neonatal radiography is presented. Neonates were categorized into four groups depending on birthweight. For a total of 378 chest and chest-abdomen radiographs, exposure parameters were recorded. Entrance surface dose (ESD) was estimated and dose-area product (DAP) was measured. Image quality evaluation was performed by two observers and was based on the visibility of certain anatomical features and catheters placed during treatment using a five-grade scale. ESD values increased with neonatal weight and demonstrated wide variation (16.4-76.9 microGy, mean 38.2 microGy). A wide variation was also observed in DAP values (1.2-15.0 mGycm2, mean 7.2 mGycm2). Image quality evaluation revealed the feasibility of achieving a diagnostically satisfactory image (score >70%) using both low and high tube voltage techniques, with the latter resulting in reduced ESDs. The majority of estimated ESDs are in accordance with the reference level of 50 microGy recommended by the National Radiological Protection Board for neonatal radiography. The results suggest that the use of high tube voltage techniques could result in further reductions in neonatal dose, without image quality degradation, underlying the requirement for establishing standard examination protocols for neonatal radiography with respect to neonatal weight.

Cardiac involvement in postnatal rubella.

Two cases of rubella myocarditis are reported: a 6-year-old boy who developed a complete, distal to His, atrioventricular block, during the third day of illness; and a 12-year-old boy who developed myocarditis with congestive heart failure 20 days following rubella infection. Although permanent pacing was required in the first patient, six years later he showed a normal growth and maintained normal activity. The second patient has deteriorated markedly and 6 months after the initial illness he had severe heart failure. It should be noted that myocarditis with abnormalities of the conduction system or congestive heart failure may be a complication to postnatal rubella.

Gaucher disease: treatment of hypersplenism with splenic embolization.

Hypersplenism is a frequent complication of Gaucher disease requiring splenectomy. A patient with Gaucher disease and severe hypersplenism was treated with partial splenic embolization to avoid the increased risk of serious infectious complications and deterioration of the disease associated with splenectomy. A first embolization (25% ablation) was performed at 4 years. Because of persisting abdominal discomfort, failure to thrive and signs of hypersplenism a second embolization (40-50% ablation) was performed 18 months later. Subsequently, the patient's health improved remarkably and 4 years later he achieved normal growth, maintains normal haematologic parameters, is free of symptoms and has no skeletal abnormalities. No serious infections have occurred. The size of the liver and the spleen has not changed appreciably. It appears that partial splenic embolization may be preferable to splenectomy in patients with Gaucher disease, especially in those of young age.