Problems and Objectives for Learning, Discussion, Review, and Self Assessment
Medical Image Characteristics and Quality Factors
Resources and References The Physical Principles of Medical Imaging Online Module Online Textbook Visuals for Discussion
Explain the concept of contrast sensitivity and it's significance in medical imaging.
Compare the contrast sensitivity characteristics of general radiography and MRI for visualization of soft tissue.
Identify the common radiographic procedure that requires the highest contrast sensitivity and explain why.
While looking at some general radiographs and mammograms, identify some of the objects that represent anatomical detail or very small signs of disease, estimate their dimensions.
Describe the basic relationship between image blurring and visibility of detail.
Compare and rank the various medical imaging modalities with respect to blurring and visibility of detail. NOTE: In later units we will learn the factors in each imaging modality that have an effect on blurring and visibility of detail.
Describe the general appearance of image noise.
While looking at images from each modality identify the image noise, Identify the modalities that appear to produce images with relatively low noise, with relatively high noise.
Describe the effect of noise on visibility of objects within an image and identify the object characteristic that might have reduced visibility in the presence of noise. NOTE: In later units we will learn the factors in each imaging modality that produce and have an effect on the noise.
Define and describe image artifact.
Recognize common image artifacts in images from each modality. NOTE: In later units we will learn the conditions and factors in each imaging modality that produce and have an effect on artifacts
Identify and describe three possible types of medical image distortion.
Identify and describe three major viewing condition factors that have an effect on the visibility of objects within a medical image.
Describe the factors that produce optimum viewing conditions for medical images.
Describe the special viewing conditions required in mammography and explain how they are achieved.
Explain and compare the two characteristics of a diagnostic procedure: sensitivity and specificity.
Define and briefly describe the clinical significance of: True Positive, False Positive, True Negative, False Negative.
Sketch a receiver operating characteristic (ROC) curve, label the scales, and describe factors that determine the position of the human operating point.
Interpret the general results of a receiver operating characteristic (ROC) analysis.
Briefly describe the clinical application of ROC analysis.