The coexistence of tiny punctate granules and similarly bright lines is the hallmark of connective tissue. There is a brighter and relatively large granule in the ventral small lesion in the upper image which might be either a punctate echogenic focus or a sign of fibrotic changes.

There is no doubt of the origin of the hyperechogenic figure in the cystic lesion, this is a typical comet-tail artifact.

At first sight the interpretation of these figures seems to be difficult. However, this lesion is in the same patient whose other lesion is presented in the left images. It is reasonable to conclude that similarly bright figures within lesions presenting an identical echo pattern have the same origin.

Small granules dominate the nodule. At least two of them have dorsal narrowing tale. The remaining figures are similarly bright therefore these are very likely also comet-tail artifacts.

It is very difficult to categorize these figures. Considering the final diagnosis even the small pale figures might be punctate echogenic foci because there are no similarly pale lines. The two large bright granules are more typical forms of punctate echogenic foci. Note that there is a less hyperechogenic shadow not only dorsal but even ventral to the larger one. It means that this figure is not a comet-tail artifact but the granule is located in a minimally hypoechogenic parenchyma.

Suspicion of papillary carcinoma (cytological diagnosis)

The coexistence of lines and granules of similar brightness in the most hypoechogenic lesion (left images) proves that these figures are connective tissue. The less hypoechogenic lesion in the right upper image also has non-specific figures.
The least hypoechogenic lesion (left images) presents only granules which correspond to punctate echogenic foci.

The presentation of the granules is similar in these cases. However the benign lesion has several granules with dorsal tail, therefore these correspond more likely to comet-tail artifacts than to punctate echogenic foci. On the other hand, the complex structures in the malignant nodules are composed of multiple granules. It is worth comparing the figures marked with arrows.

The bright granules partly have dorsal tail, these are therefore comet-tail artifacts. Moreover, this is a small cyst; therefore the granules within the fluid cannot be anything other than colloid crystals.

There are large bright granules in the lower, longitudinal image. With this older equipment these figures might be punctate echogenic foci.

Hyperechogenic lines of various levels of brightness dominate the nodule. These figures are presentations of the connective tissue.

There are different types of hyperechogenic figures including colloid crystals without the typical tail in the cystic area, figures caused by a posterior back wall enhancement and a connective tissue in the presence of bright granules and lines in the solid part of the nodule.

The two bright spots must be held as punctate echogenic foci.

The lesion presents two or three relatively bright granules. In the absence of similarly bright lines these are punctate echogenic foci.

There are several typical forms of comet-tail artifacts in the upper image. There are two hyperechogenic figures, and the larger one is very difficult to categorize. Considering the presence of comet-tail artifacts these ambiguous figures probably belong also to the same subgroup of figures.

There are several bright tiny hyperechogenic granules which have to be grouped as punctate echogenic foci. The large, complex figure in the central part of the lower image corresponds to amyloid deposit: there are small bright hyperechogenic granules within a less hyperechogenic, irregularly shaped structure.

The lesion has non-specific lines and granules. There are two more bright granules, one in the upper-ventral and another in the lower part of the lobe. These might be punctate echogenic foci.

Bright granules coexist with lines - the typical presentation of proliferation of connective tissue. (The lines are better seen in the video.)

Hyperechogenic lines and granules coexist, these figures represent connective tissue. In the presence of the acoustic shadow the lesion has to contain coarse calcifications, too.