Small Thyroid Gland

Introduction

The thyroid is one of the largest endocrine organs in the body, but on the other hand is small compared to most other organs. It weighs about 15- 35 grams measuring approximately 4-5cms cm long, 2-2.5 cm wide and 1 -2 cm thick, in the average adult. The isthmus is 2-6mm in A-P diameter and is up to 20 mm. in width.

The the most important dimension when considering enlargement of the gland is the A-P diameter which should not be >2cms. The length is considered large when in the 4-6cms range and trannsverse should not be larger than 2.8cms.

The small gland is measures lesss than 4 cms inlength, less than 2cms wide, and less than 1cms thick.

Normal (a and b) and Small (c and d)

The patient is a 70year female who shows diffuse atrophy of her thyroid by this ultrasound examination. A normal thyroid gland in sagittal (a) and transverse (b) planes is juxtaposed on the atrophied gland(c,d) The gland is mildly heterogeneous. The left lobe of the thyroid measures 4.1cms (craniocaudad), by .8 cms (A-P) by 1.1cms (transverse). The sagittal view shows mildly coarse heterogeneous echo texture. The transverse view shows a normal shape. The isthmus is normal in size. These findings suggest age related involution of the gland.

The Small Thyroid Gland

The patient is a 70 year female who shows diffuse atrophy of her thyroid by this ultrasound examination. The gland is mildly heterogeneous. The left lobe of the thyroid measures 4.1cms (craniocaudad), by .8 cms (A-P) by 1.1cms (transverse). The sagittal view shows mildly coarse heterogeneous echo texture. The transverse view shows a normal shape. The isthmus is normal in size. The color flow Doppler study seems hypervascular but the significance of this finding is not known. These findings suggest age related involution of the gland.

Hypoplastic Left Lobe

A normal ultrasound of the thyroid gland with a hypoplastic left lobe is demonstrated. Image a is a transverse image, while image b is a sagittal view of the right lobe, and image c is a sagittal view of the left lobe. The normal right lobe (a,b) measures 4.6cms (length) x 1.4cms (A-P anteroposterior) X .7 cms (transverse TRV) and the hypoplastic left lobe measures 2.9cms (craniocaudad), by .6cms (A-P) by .7cms (transverse).