FNAC of thyroid cyst:

 
This was a large cystic lesion of the right lobe of thyroid. Ultrasound guided fine needle aspiration of the cyst helped to drain the contents of the cyst as well as to ascertain the nature of the cyst contents. Ultrasound guided aspiration done here shows the needle tip descending into the cyst (seen as the bright mobile echogenic focus in the cyst lumen). The ultrasound probe (here) is placed perpendicular to the long axis of the needle- resulting in the needle tip being visualized. If the needle's long axis is parallel to the ultrasound beam (and the ultrasound probe), a linear echo of the needle can be visualized.
See: http://radiographics.rsna.org/content/28/7/1869.full 

Sonography quiz- What is your diagnosis?

This was a male patient with history of hematuria. What is your diagnosis? This ultrasound video shows a transabdominal scan in the first 2 parts of the video; the last part of the video shows a Transrectal ultrasound (TRUS) imaging of the bladder of the urinary bladder.

Answer: this is a freely mobile calculus in the urinary bladder. Seen rolling across the inner bladder surface on change in position. The TRUS imaging of the this case needed a lot of patience to capture this rather elusive urinary bladder stone.

Ultrasound guided thyroid FNA biopsy:

FNA or fine needle aspiration of the thyroid is mainly used to distinguish benign from malignant thyroid nodules. However, it is also useful in the biopsy of diffuse enlargement of the thyroid as is seen in Hashimoto thyroiditis and diffuse infiltration of the thyroid in lymphomas and certain forms of metastases (colonic adenocarcinoma spreading to the thyroid). In the case of Hashimoto thyroiditis, FNA biopsy helps to distinguish Hashimoto thyroiditis from lymphomas and papillary carcinoma of the thyroid which may coexist with the primary disease.

Method: the aim of ultrasound guidance whilst performing the FNA biopsy is provide visualization of the needle tip and guide it to the exact location within the thyroid where the nodule is located or where there is maximum possibility of collecting diseased tissue. This short ultrasound video clip shows the needle tip (seen as an echogenic linear focus) moving to and fro within the left lobe of the thyroid. The aim of the FNA study in this case was to rule out lymphoma involving the thyroid:

 

References: http://radiographics.rsna.org/content/28/7/1869.full
(free article on Ultrasound guided FNA biopsy of the thyroid).