Introduction

     Goiter - pathological enlargement of thyroid - is observed in a number of thyroid pathologies - diffuse euthyroid goiter, diffuse toxic goiter, acute thyroiditis, hyperplastic variant of autoimmune thyroiditis, diffuse-nodular and diffuse-multinodular goiter, adenomatous goiter, carcinomas, lymphomas.
     The term  enlargement is traditionally associated with the change of dimensions and for thyroid it is usually associated with the volume enlargement. In this context a significant number of publications is devoted to the study of thyroid dimensions from the point of view of ultrasonic method and some of them are mentioned in bibliography.
     However, it is possible and sufficient to regard  enlargement only as a change of dimensions when estimating physical objects but for biological tissues and especially for disease it is highly inconsiderate opinion and discredit of visualization methods as a whole to use only one sign - enlargement.
     Why then is goiter regarded only from the point of view of organ dimensions being them average or median values for the definite age, sex, weight, height, surface area? Actually this sign is extremely important but the ultrasonic method allows to detect the whole complex of changes described in the atlas.
     In goiter the topographic and anatomic interrelation of thyroid with surrounding organs changes - the upper poles can reach the upper horns of thyroid cartilage and the lower ones - thoracic part of trachea and even spread down to the bifurcation of the trachea. The upper edge of the isthmus can reach cricothyroid ligament.
     The form of thyroid significantly changes  - the front surface bulges and shifts to the front, the lateral edge becomes straight anmd shifts outward. The back surface bulges and shifts to the spinal column. The  median edge  shifts to the sagittal line and repeats the trachea form.
     The echostructure and optical density of  thyroid tissue are disturbed.
     The changes in trachea appear - its compression and shift to the spinal column are observed. The extension of trachea constriction can amount to significant proportions that is clearly seen in the first 5 to 7 trachea rings.
     The esophagus gullet is uniformly deformed in depth and width.
     The anterior group of muscles - musculus sternothyroideus and sternohyoideus - dramatically thins. The changes in the posterior group of muscles also appear - the musculus longus capitis, neck and anterior, medius and posterior musculus scalenus thin and shift backwards.
     The prevertebral fascia consolidates.
     The main neck  vessels - arteries and veins - are shifted forward from the sagittal line and backwards. The venous plethora is observed.
     It is rather difficult to see all this range of ultrasonic signs and it is especially complicated to detect them not knowing the normal ultrasonic anatomy.
     The analysis of tens of thousands of thyroid ultrasonic images allowed to reveal and understand the dynamic of  the  whole range of ultrasonic changes observed in goiter and to use them in the initial goiter diagnostics.
     Method of automatic lateral tomography from my point of view is the best clinical method of the goiter diagnostics in the world practice. The two-dimensional thyroid reconstruction by height, depth and width  was succeeded on its base. The step towards three-dimensional reconstruction of thyroid image and surrounding organs was made.
     I hope that the material presented in the atlas extended the possibilities of ultrasonic method in goiter diagnostics.

Japan. Nagasaki.
March, 2000.
Parshin V.S.

 
 

 

Publishing. Department of International Health and Radiation Research, Atomic Bomb Disease Institute, Nagasaki University School of Medicine, Nagasaki Association for Hibakushas Medical Care (NASHIM), Secretariat of the Cooperation Committee, Japanese Ministry of Foreign Affairs.