EVALUATION OF IMAGE QUALITY
In this paper we describe an overarching framework that allows us to interpret the information from an image. Starting with the imaging device, consideration will be given to the measurement of the quality of the raw data detected by the instrument. This uses Bayesian signal detection theory to combine the large area transfer characteristic, the modulation transfer function and the noise power spectrum in a single measure of quality.Then we will discuss how to assess the quality of the displayed image by measuring human performance directly. The most complete description of observer performance is provided by Receiver Operating Characteristic (ROC) analysis, which estimates all the combinations of sensitivity and specificity available from an imaging procedure. How subjective measures of image quality can be combined with the objective assessment of performance will be investigated. Finally, we will show how quality can be extended to the judgement of the influence of imaging technology on the clinical management of patients, including the quality of life of the patient.
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