A punctate echogenic focus is a round bright granule. The size of this figure is less than 1 mm, usually is around 0.5 mm. A lesion which has typical punctate echogenic foci (microcalcifications) almost always presents less bright granules, too. The latter might be non-typical forms of microcalcifications or non-specific granulations. In fact the identification of punctate echogenic foci (including microcalcifications) is a matter of exclusion other forms of hyperechogenic figures, i..e comet-tail artifacts, connective tissue and posterior back wall enhancement. All of the latter have additional features lacking in the event of punctate echogenic foci. Nevertheless, it means that atypical presentations of these figures might mimic punctate echogenic foci including microcalcifications.
The presentation of punctate echogenic foci depends highly on the ultrasound device. If the resolution is worse than the granule is larger (see the lowest image). On the other hand there is a very harmful trend in newer equipments which might cause difficulty in recognition of punctate echogenic foci (microcalcifications). This trend is the "overharmonization" which means that the normal grainy structure of the thyroid is masked in order to gain a more harmonic, beautiful image. It has practically no sense, moreover the overharmonization masks the pathologic hyperechogenic granules, the microcalcifications, too, which is a very serious hazard.
We prefer the term punctate echogenic foci instead of microcalcification in order to avoid misnomer for granules caused by other pathological structures. Nevertheless, in many publications and even in other parts of this website we use the term "microcalcification" for every punctate echogenic foci.