Radiation Reduction in the Pediatric Catheterization Laboratory Using a Novel Imaging System

OBJECTIVES

Radiation dose was compared between two modern imaging systems with different x-ray tube technology (Megalix vs Gigalix) and detector type (amorphous vs crystalline silicon) at the same institution.

BACKGROUND

Further reduction in radiation dose than currently reported may be achievable with advances in x-ray tube and detector technology.

METHODS

Radiation dose (air kerma, dose-area product [DAP]) was retrospectively compared for post-transplant pediatric patients undergoing right heart catheterization/biopsy (fluoroscopy only) or "annual" catheterization with coronary angiography in one of two imaging systems between January 2014 and December 2016. Comparisons were also made with published radiation doses.

RESULTS

A total of 122 right heart catheterizations with biopsy were performed in the Megalix/amorphous silicon (Si) lab and 168 in the Gigalix/crystalline Si lab. Age and weight were not statistically different for the two groups. There was a 50% decrease in median air kerma (2.2 mGy vs 1.1 mGy; P<.001) and 66% decrease in median DAP (52.2 μGy•m² vs 18.0 μGy•m²; P<.001) for the Gigalix/crystalline Si lab. A total of 24 "annual" catheterizations were performed in the Megalix/amorphous Si lab and 22 were performed in the Gigalix/crystalline Si lab. There was a 57% reduction in median air kerma (458.6 mGy vs 198.6 mGy; P<.001) and a 46% reduction in median DAP (2548.0 μGy•m² vs 1367.1 μGy•m²; P<.01) for the Gigalix/crystalline Si lab. Similar reductions were found on comparison with published doses.

CONCLUSION

The Gigalix tube and crystalline Si detector decrease radiation dose by 50%-60% for fluoroscopy and cine acquisition in pediatric patients.

Parotid TB

TB of the parotid is rare and only about 100 cases have been reported in the world literature. Often the diagnosis is made only after the surgery performed for a suspected neoplasm. We describe three patients with diffuse form of parotidTB without any evidence of tubercular focus elsewhere. Fine needle aspiration cytology confirmed the diagnosis in two cases, while the third case was diagnosed only after surgery.