Estimation of skeletal bone mineral density by means of the trabecular pattern of the alveolar bone, its interdental thickness, and the bone mass of the mandible.

OBJECTIVE: We sought to evaluate the use of the alveolar trabecular pattern, the mandibular alveolar bone mass (MABM) measured by photodensitometry, and the interdental alveolar thickness for prediction of the skeletal bone mineral density (BMD). STUDY DESIGN: MABM and the coarseness of trabeculation were assessed by using periapical radiographs in 80 dentate women. The interdental alveolar thickness was measured on casts, and BMD of the forearm with dual X-ray absorptiometry. RESULTS: Significant correlations were found between skeletal BMD and MABM (r = 0.46, P <.001) as well as the coarseness of the trabeculation (r = 0.62, P <.001). The interdental alveolar thickness improved the correlation between skeletal BMD and MABM (R2 = 0.44, P <.001). Age, but not interdental thickness, improved the correlation between the coarseness of trabeculation and skeletal BMD (R2 = 0.52, P <.001). CONCLUSION: Evaluation of the coarseness of trabeculation of the alveolar bone as seen on intraoral radiographs is a helpful clinical indicator of skeletal BMD and better than densitometric measurements of the alveolar bone. Dense trabeculation is a strong indicator of high BMD, whereas sparse trabeculation may be used to predict low BMD.

Radiation-absorbed doses and energy imparted from panoramic tomography, cephalometric radiography, and occlusal film radiography in children.

The absorbed doses and energy imparted from radiographic examinations of children, using panoramic tomography (PTG), cephalometric radiography (CPR), and maxillary frontal occlusal overview (FOO), were examined. The absorbed dose at various sites of the head were measured with TL dosimeters in a phantom and in patients. The energy imparted was calculated from measurements of areal exposure using a planparallel ionization chamber. The maximum absorbed doses for panoramic tomography were located around the lateral rotation center, for cephalometric radiography in the left (tube side) parotid region, and for frontal occlusal radiography in the nose. The absorbed doses in the eyes, thyroid gland, and skin are discussed and compared with previous reports and, for the most part, are found to be in agreement. The mean energy imparted from all three examination methods is 5 mJ with about 57 percent from panoramic, 33 percent from cephalometric, and 10 percent from frontal occlusal examinations. The energy imparted from cephalometric radiography can be reduced to about 10 percent with the use of an improved examination technique, leaving panoramic tomography responsible for contributing about 80 percent of the total energy imparted.

Patient radiation doses in upper GI examinations: a comparison between conventional and double-contrast techniques.

A total of 60 patients, divided into 3 groups with 20 patients in each, were examined with 3 different techniques: group 1 -- conventional technique, exposure at 120 kV; group 2 -- double-contrast technique (hypotonic gastrography, HG), exposure at 80 kW; group 3 -- HG, exposure at 120 kV. All examinations were performed in the same examination room and by the same radiologist. Absorbed doses to skin, thyroid, breasts, and gonads as well as energy imparted were measured. The only significant dose enhancements found when using double-contrast instead of conventional technique were in the female breasts and then only if the voltage was in the lower range. With exposure at 120 kV there was little difference in absorbed dose, but a significant advantage with respect to energy was imparted when using a double-contrast technique instead of a conventional technique. The testes doses were very low in all 3 types of examinations, and it seems that use of a testes shield is hardly motivated. With regard to both diagnostic accuracy and patient radiation dose, there can be no reason to use a conventional technique for upper GI examinations.

Absorbed doses at CT of the kidneys and at urography.

Radiation doses to the skin, ovaries and testes were measured at urography and CT examinations of the kidneys and adrenals. The absorbed dose to the breasts and bone marrow at CT was estimated as well as the mean bone marrow dose at urography. The results were compared with previous measurements of absorbed doses and energy imparted at abdominal angiography including nephroangiography. CT of the kidneys involves a considerably lower risk for late biologic effects to the patient than urography and, in particular, angiography.