The Comparative Study of Imaging Characteristics Between "Wet"and "Dry"Laser Film / 实用放射学杂志

ABSTRACT

Objective By estimation and analysis of imaging characteristics of "dry"and "wet" laser print to appreciate the imaging quality of two different printing ways and its advantages and disadvantages respectively.Methods ①28 routine MRI and 28 routine CT images were selected,the imaging quality of MR and CT images including brightness,contrast,detail display,diagnostic performance and general impression were evaluated by 6 radiologists;②CT and MR images of skull,lumbus,knee and hand joint adjusted to the best states, then printed by "dry" and "wet" laser printer;③The sensitive characteristic curve both "dry" and "wet" printing were made with opital densimeter,SMPTE card,then an objective evaluation of stabilization was done.Results ①The imaging quality for the dry imaging possess in 56 cases,the much worse was 0.3%,the best was none,the slightly worse,medial and slightly better was 31.9%,58.9% and 8.9% respectively;②The maximum density of the dry film and the wet film was 3.34 and 3.62 respectively,the dynamic range of the latter was more wide than that of former;③The wet films exposed to temperatures from 40℃ to 100℃,did not show a noticeable alteration in optical density,but the dry film showed gray scale degradation at temperatures above 70℃.Conclusion In imaging quality,stability of film,brightness and contrast of film,"wet" laser film is better than that of "dry" laser film,but "dry"laser film has still good diagnostic function that can be used in clinical diagnosis.