Image quality assessment and radiation doses in intraoral radiography.

OBJECTIVE: The purpose of this study was to investigate 2 very important aspects of dental radiographic image quality, exposure time settings and film processing, and to assess their relation to radiation dose. STUDY DESIGN: Radiographic images of a dental image quality test tool were obtained in 108 dental practices. Image quality and film processing were evaluated both subjectively and objectively by comparing films developed by the dentists with films developed under optimum conditions. The data consisted of measured values of optical density, which were used to obtain image contrast, and scores of image quality and film processing, which were based on criteria set by 2 independent oral radiologists. Entrance surface dose was also measured for the technique used at each dental practice. RESULTS: The results indicate a great variability of exposure time settings used by the dentists for imaging the phantom. Film processing was inadequate in most of the practices, which resulted in poor image quality and increased patient radiation doses. The mean entrance surface dose for imaging the phantom was 3.8 mGy. CONCLUSION: Intraoral imaging techniques and film processing must be standardized to improve image quality and further reduce patient radiation doses.

The effects of early captopril treatment on left ventricular volumes and function in patients with and without depressed global ejection fraction after acute myocardial infarction.

To determine the effects of captopril on left ventricular volumes and function in patients with and without depressed ventricular function following acute myocardial infarction (AMI) we studied 78 patients with a first Q wave AMI and no clinical evidence of heart failure. All patients underwent radionuclide ventriculography (RVG) on the 4th day after admission and were then randomly assigned to receive conventional treatment alone (36 patients, control group) or with the addition of oral captopril, 25 mg three times daily (42 patients, captopril group). RVG was repeated one month after the baseline examination. After one month the left ventricular ejection fraction (LVEF) significantly increased in the captopril group (from 43.2 +/- 1.3 to 50.9 +/- 1.6%, P < 0.001) and remained relatively unchanged in the control group (from 47 +/- 1.3 to 49.2 +/- 1.7%, P = ns). In the captopril group the subgroup of patients with a baseline LVEF < 45% demonstrated a significant decrease in end-systolic volume index (ESVI) (from 53.3 +/- 3.2 to 42.4 +/- 2.8 ml. m-2, P < 0.002) and a highly significant improvement in LVEF (from 36.3 +/- 1.3 to 49.6 +/- 1.8%, P < 0.00005). In the control group, LVEF also increased in those in whom it was < 45% (from 38 +/- 1.4 to 42 +/- 2.4%, P < 0.01), but the increase was less than that in the captopril group (P < 0.01), mainly due to an increase in end-diastolic volume index (EDVI) (from 78.2 +/- 4.6 to 84.6 +/- 12.3 ml.m-2, P = ns).(ABSTRACT TRUNCATED AT 250 WORDS)