Dose-reducing strategies in combination offers substantial potential benefits to females requiring X-ray examination.

This work, using an adult anthropomorphic phantom, aimed to establish an optimised technique for ladies of child-bearing age undergoing antero-posterior (AP) pelvis and AP and lateral lumbar spine examinations. Phase one of the work involved introducing the following dose-reducing measures individually: increased kVp, increased focus-film distances, a carbon fibre cassette, a faster film/screen combination. The second phase established an optimised technique based on a combination of the parameters listed above. Radiation dose was measured using thermoluminescent dosimeters and image quality was evaluated using anatomical criteria. All dose-reducing methods were compared with a standard technique, currently being used in a Dublin hospital. The results demonstrated that the optimised procedure reduced effective dose by 77, 62 and 66% for AP pelvis and AP and lateral lumbar spine respectively (p < 0.05) compared with the standard technique, with no significant changes in image quality. Dose-reducing measures used in combination offer substantial potential for optimisation of radiological procedures.

Diagnostic ultrasound induces change within numbers of cryptal mitotic and apoptotic cells in small intestine.

Recent work on gas filled organs, including the lung and small intestine, has concentrated on the hemorrhaging effects of ultrasound, with little attention paid to cell cycle perturbations and apoptosis--two very sensitive indicators of environmental insult. This study addresses this by exploring the effects of ultrasound on these two features. The anterior abdominal surface of anaesthetised male, adult CD1 mice was shaved and exposed to ultrasound. An 8 MHz linear array transducer was manually swept from the midline to the left mouse flank on a continuous basis. Each mouse was scanned for 15 minutes with B mode and color flow modes selected. The Thermal Index registered 1.0. Groups of mice were killed at various times after treatment, the small intestine was excised and histologically examined. Analysis of the data demonstrates a statistically significant 22% reduction in numbers of mitotic figures at 4.5 hours after the ultrasonic insult (p = 0.011). Numbers of apoptotic bodies increased by 153% (p=0.003), 166% (p=0.014) and 160% (0.001) at 1, 3 and 4.5 hours post-treatment respectively. These preliminary results suggest that bioeffects of ultrasound maybe more diverse than previously described. Further work will establish thresholds and explore mechanisms for these deterministic effects.