(1) For fibers: Begin with the largest fiber and move down in size, adding one point for each full fiber until a score of zero or one half is given, then stop. If the entire length of the fiber can be seen and its location and orientation are correct, that fiber receives a score of one. If at least half, but not all, of the fiber can be seen and its location and orientation are correct, that fiber receives a score of one half. If less than one half of a fiber can be seen or if the location or orientation is incorrect, that fiber receives a score of zero. After determining the last fiber to be counted, look at the overall background for artifacts. If there are background objects that are fiber-like in appearance and are of equal or greater brightness than the last visible half or full fiber counted, subtract the last half or full fiber scored.

(2) For speck groups: Begin with the largest speck group and move down in size adding one point for each full speck group until a score of one half or zero is given, then stop. If at least four of the specks in any group are visualized, the speck group is scored as one. If two or three specks in a group are visualized, the score for the group is one half. If one speck or no specks from a group are visualized, the score is zero. After determining the last speck group to receive a full or one-half point, look at the overall background for artifacts. If there are speck-like artifacts within the insert region of the phantom that are of equal or greater brightness than individual specks counted in the last visible half or full speck group counted, subtract the artifact speck from the observed specks, one by one. Repeat the scoring of the last visible speck group after these deductions.

(3) For masses: Begin with the largest mass and add one point for each full mass observed until a score of one half or zero is assigned, then stop. Score one for each mass that appears as a minus density object in the correct location that can be seen clearly enough to observe round, circumscribed borders. Score one-half if the mass is clearly present in the correct location, but the borders are not visualized as circular. After determining the last full or half mass to be counted, look at the overall background for artifacts. If there are background objects that are mass-like in appearance and are of equal or greater visibility than the last visible mass, subtract the last full or half point assigned from the original score.