RESUMEN
PURPOSE: To compare devices for the task of navigating through large computed tomographic (CT) data sets at a picture archiving and communication system workstation. MATERIALS AND METHODS: The institutional review board approved this study, and all subjects provided informed consent. Five radiologists were asked to find 25 different vascular targets in three CT angiography data sets (average number of sections, 1025) by using several devices (trackball, tablet, jog-shuttle wheel, and mouse). For each trial, the total time to acquire the targets (T1) was recorded. A secondary study in which 13 nonradiologists performed seven trials with an artificial target inserted at a random location in the same image data was also performed. For each trial, the following items were recorded: time until first target sighting (t2), time to manipulate the device after seeing the target, sections traversed during t2 (d1), time from first sight to target acquisition (t4), sections traversed during t4 (d2), and total trial time. Statistical analysis involved repeated-measures analysis of variance (ANOVA) and pairwise comparisons. RESULTS: Repeated-measures ANOVA revealed that the device used had a significant (P < .05) effect on T1. Pairwise comparisons revealed that the trackball was significantly slower than the tablet (P < .05) and marginally slower than the jog-shuttle wheel (P < .10). Further repeated-measures ANOVA for each secondary outcome measure revealed significant differences between devices for all outcome measures (P < .005). Pairwise comparisons revealed the trackball to be significantly slower than the other devices in all measures (P < .05). The trackball was significantly (P < .05) more accurate than the other devices for d1 and d2. CONCLUSION: The trackball may not be the optimal device for navigation of large CT angiography data sets; the use of other existing devices may improve the efficiency of interpretation of these sets.
Asunto(s)
Angiografía/instrumentación , Interpretación Estadística de Datos , Tomografía Computarizada por Rayos X/instrumentación , Humanos , Distribución Aleatoria , Encuestas y CuestionariosRESUMEN
Research findings based on the retrospective reports of depressed individuals have long been held suspect because of possible negative reporting biases associated with depression. In the present study we assess the stability of retrospective reports of past traumatic events, past depressive episodes, parental depression, and parental substance abuse in a sample of 234 adults whose depression status changed over two assessments conducted one year apart. Depression status was found to affect reporting of number of past depressive episodes and past traumatic events, but not reporting of parental psychopathology. Implications of these findings are discussed for research that relies on the retrospective self-reports of depressed participants.