This document discusses imaging of the thyroid gland and various thyroid conditions. It begins with a description of normal thyroid gland anatomy and imaging appearance on ultrasound, CT, and MRI. It then covers various pathological conditions such as diffuse goiter, nodular goiter, hyperthyroidism, hypothyroidism, and developmental abnormalities. Differential diagnoses for diffuse versus focal/nodular thyroid abnormalities as well as benign versus malignant nodules are also discussed.

1. ‫هللا‬ ‫بسم‬
‫الرحيم‬ ‫الرحمن‬
Dr Ahmed Esawy

2. Dr. Ahmed Eisawy
MBBS M.Sc MD
Dr Ahmed Esawy

3. FULL STORY
OF
THYRIOD IMAGING
(US.CT.MRI.NUCLEAR)
GIOTRE
HYPERTHYRIODISM
(HYPERTHYROXINEMIA)
HYPOTHYRIODISM
Dr Ahmed Esawy

4. CONTENTS
1-Normal thyriod gland imaging
2-pathology
3-differential diagnosis
4-developmental thyriod gland disease
5-diffuse thyriod gland disease
(hyperthyriodism/hypothyriodism)
6-benign mass /nodule
7-malignant mass /nodule
8-TIRAD
9-nuclear thyriod gland imaging
Dr Ahmed Esawy

5. 1-Normal thyriod gland imaging
Dr Ahmed Esawy

6. THE THYROID GLAND
OVERTRACHEA
TWO LARGE LATERAL LOBES CONNECTED BY AN
ISTHMUS
15 to 20 g
FUNCTIONAL UNIT ISTHE FOLLICLE: EPITHELIAL
CELLS AROUND A HOLLOWVESSICLE FILLEDWITH
THYROGLOBULIN
Dr Ahmed Esawy

8. Transverse US scan of normal
thyroid/neck
Dr Ahmed Esawy

9. SONOGRAPHICALLY DIVIDED INTOTHREE
SEGMENTS UPPER ,MIDDLE ,LOWERTHIRDS
Dr Ahmed Esawy

10. NORMAL THYROID GLAND
THE NORMAL THYROID HAS THIS “GROUND GLASS”APPEARANCE. IT IS
BORDEREDANTERIORLY BYTHE STRAP MUSCLES(SM), LATERALLY BYTHE
CAROTIDARTERY (C), INTERNALJUGULAR VEIN(J),AND STERNOCLEIDOMASTOID
MUSCLE(SCM). THE LONGUS COLI MUSCLE(LC) LIESPOSTERIORLY. THE
ESOPHAGUS (E) PROTRUDESON THELEFT.
RIGHT LEFT
SMSM
SCM
SCM
TRACHEA
E LC
LC
C
C
J
Dr Ahmed Esawy

11. Normal Anatomy
Dr Ahmed Esawy

12. Normal Anatomy
Dr Ahmed Esawy

13. Normal
Thyroid
Adult Thyroid
40-60 mm long
13-18 mm AP
Isthmus 4-6 mm AP
Newborn: 18-20
mm long; 8-9 mm
AP
Age 1: 25 mm
long; 12-15 mm AP
Dr Ahmed Esawy

14. Longitudinal US scan of
normal thyroid/neck
Dr Ahmed Esawy

15. Normal thyroid gland:
US
Dr Ahmed Esawy

16. Normal echo-pattern
Dr Ahmed Esawy

17. Normal thyroid gland : US
Dr Ahmed Esawy

18. Normal thyroid gland and thyroid mass. A, Enhanced axial neck CT at the level of the thyroid
gland. Note the normal right and left lobes of the thyroid gland (L) and the isthmus (arrows).
Dr Ahmed Esawy

19.  Normal thyroid gland. UnenhancedCT images through the upper portion
(A), midportion (B), and lower portion (C) of the thyroid gland demonstrate
the two lobes of the gland (black arrowheads) as structures of relatively high
attenuation value adjacent to the trachea (T).The thyroid isthmus (white
arrowhead) connects the right and left lobes. C, common carotid artery; J,
internal jugular vein; E, esophagus; arrows, longus colli muscles.
Dr Ahmed Esawy

20.  Normal thyroid gland. Unenhanced CT images through the upper portion (A),
midportion (B), and lower portion (C) of the thyroid gland demonstrate the two
lobes of the gland (black arrowheads) as structures of relatively high attenuation
value adjacent to the trachea (T).The thyroid isthmus (white arrowhead)
connects the right and left lobes. C, common carotid artery; J, internal jugular
vein; E, esophagus; arrows, longus colli muscles.
Dr Ahmed Esawy

21.  Normal thyroid gland. UnenhancedCT images through the upper portion
(A), midportion (B), and lower portion (C) of the thyroid gland
demonstrate the two lobes of the gland (black arrowheads) as structures
of relatively high attenuation value adjacent to the trachea (T).The
thyroid isthmus (white arrowhead) connects the right and left lobes. C,
common carotid artery; J, internal jugular vein; E, esophagus; arrows,
longus colli muscles. Dr Ahmed Esawy

22. non-enhanced CT demonstrating slightly hyperdense thyroid gland compared to
muscle tissue
Dr Ahmed Esawy

23. contrast enhanced CT demonstrating enhancement of thyroid tissue compared
to muscle.
Dr Ahmed Esawy

24. T1wTSE image showing slight hyperintensity of thyroid gland compared to muscle
tissue.
Dr Ahmed Esawy

25. T2wTSE image showing hyperintensity of thyroid gland compared to muscle tissue.
Dr Ahmed Esawy

26. Axial MR images of the neck.
A,T1-weighted image shows mild
hyperintensity in the thyroid
gland.
B,T2-weighted image shows a
more pronounced hyperintensity,
compared with muscle, in the
thyroid gland.
Dr Ahmed Esawy

27. 2-pathology
Dr Ahmed Esawy

28. Abnormalities of thyriod
functional Structural
anatomical
Enlarged =goitre NOT ENLARGED
FOCAL(mass / nodule)
hyperthyriodismhypothyriodism
euthyriod
NODULAR DIFFUSE Dr Ahmed Esawy

29. GOITRE
=thyroid enlargment
(British English) or goiter (American English) (from the Latin gutteria, struma) is
a swelling of the neck or larynx resulting from enlargement of the thyroid
gland (thyromegaly), associated with a thyroid gland that is not functioning properly.
Worldwide, over 90% cases of goitre are caused by iodine deficiency
Goitrogens are substances (whether in drugs, chemicals, or foods) that disrupt the
production of thyroid hormones by interfering with iodine uptake in the thyroid
gland.This triggers the pituitary to releaseTSH, which then promotes the growth of
thyroid tissue, eventually leading to goiter.
Dr Ahmed Esawy

30. Dr Ahmed Esawy

31. Goiterogenesis
Iodine deficiency results in hypothyroidism
IncreasingTSH causes hypertrophy of thyroid (diffuse
nontoxic goiter)
Follicles may become autonomous; certain follicles will
have greater intrinsic growth and functional capability
(mult inodular goiter)
Follicles continue to grow and function despite
decreasingTSH (toxic mul tinodular goiter)
Sporadic vs. endemic goiter
Dr Ahmed Esawy

32. Simple (Colloid) Goiter
 Diffuse goiter
Usually euthyroid
Peaks in puberty
Endemic goiter
Compensatory TSH
Follicular cell hypertrophy and
hyperplasia
Goiterogens (eg, cassava)
Non endemic or sporadic less
common
Rare hereditary defects in thyroid
hormone synthesis
Note distension of follicles with colloid
and flattening of epithelial cells
Dr Ahmed Esawy

33. Multinodular Goiter
Most simple goiters become transformed into
multinodular goiters.
Nontoxic or toxic (induce thyrotoxicosis)
No ophthalmopathy or dermopathy
May cause cosmetic disfigurement and tracheal
compression
May induce the superior vena caval syndrome
Differentiation of a dominant nodule from a thyroid
tumour may be difficult.
Retrosternal extension
Dr Ahmed Esawy

34. 3-Differential diagnosis
Dr Ahmed Esawy

35. GIOTRE
DIFFUSE FOCAL/NODULAR
MULTINODULAR UNINODULAR
NON-TOXIC TOXIC
Structural / Anatomy
Functional /biochemical
Dr Ahmed Esawy

36. DIFFUSE GIOTRE
•the whole thyroid appearing to be enlarged Size
hyperthyriodism
Graves disease
Suppurative thyroiditis
Drug-induced thyroiditis
Riedel s thyroiditis
Iodine deficiency
Organification defect
pregnant ,menopause thyroiditis
Silent thyrioditis
hypothyriodism
Hshimoto s thyroiditis
Iodine deficiency
Radiation exposure
Subacute thyroiditis
post partum thyroiditis
Dr Ahmed Esawy

37. GIOTRE
DIFFUSE FOCAL/NODULAR
MULTINODULAR
UNINODULAR
HYPERTHYRIODISM
thyrotoxic giotre
HYPOTHYRIODISM
Hypothyriod giotre
Euthyroid goiter:
- Diffuse goiter – U/S
- MNG – U/S, FNA for dominant noduleDr Ahmed Esawy

38. NODULAR GIOTRE
BENIGN
ADENOMA
NEOPLASM
COLLIOD
Cyst
Complex cyst
Focal thyrioditis
MALIGNANT
As function: biochemical
- hot (toxic)
- cold (N :TSH)
cold nodule in a toxic thyroid (as may occur in
Grave’s disease)Dr Ahmed Esawy

39. Nontoxic Goiter
 Simple, Colloid, or Multinodular
 Enlargement of entire gland without
producing nodularity and without evidence of
functional disturbance (euthyroid)
 Causes
 Lack of Iodine
 Compensatory increase of TSH = follicular cell
hypertrophy
 Sporadic Goiter
 Diffuse, Uninodular, or multinodular
 Ingestion of Substances, hereditary enzyme
defects
 Simple Goiters may evolve =
Multinodular Goiters
 Calcification, Degeneration, Fibrosis,
and Hemorrhage
Dr Ahmed Esawy

40. BENIGN NODULAR GIOTRE
Non toxic
NEOPLASM
Benign thyroid cysts
(degenerated nodules)
Simple cyst
Haemorrhagic Cystic nodule
in solid tumour
COLLIOD
Dominent colliod nodule in MNG
uninodular
Adenoma
macrofollicular (simple colliod)
microfollicular (fetal)
embryonal (trabecular)
hurthe cell adenoma
atypical adenoma
adenoma with papillae
signet ring adenoma
Inflammatory disorder
subacute thyrioditis
lymphocystic thyrioditis
granulomatous disease
(sarciodosis/TB)
abscess
developmental
dermiod
unilateral lobe agenesis
Dr Ahmed Esawy

41. MALIGNANT NODULAR GIOTRE
MALIGNANT
Papillary carcinoma
Follicular carcinoma
Hurthle cell tumor
MedullaryThyroid Carcinoma
Anaplastic Carcinoma
Lymphoma of thyroid
Dr Ahmed Esawy

42. NODULAR GIOTRE
UNINODULAR
MULTINODULAR
MNG
INACTIVE
COLD
TOXIC NODULE
TOXIC NODULE
TOXIC MULTINODULAR GIOTRE INACTIVE
COLD
MALIGNANT BENIGN
Dr Ahmed Esawy

43. Cold Thyroid Nodule
 BENIGNTUMOR
 Nonfunctioning adenoma
 Cyst (20%)
 Involutional nodule
 Parathyroid tumor
 INFLAMMATORY MASS
 Focal thyroiditis
 Granuloma
 Abscess
 MALIGNANTTUMOR
 Carcinoma
 Lymphoma
 Metastasis
Dr Ahmed Esawy

44. “Cold” nodule = focal defect
Dr Ahmed Esawy

45. Cold nodule, R lobe (99mTcO4)
Dr Ahmed Esawy

46. Cystic Areas in Thyroid
 25% of all thyroid nodules!
 Anechoic fluid + smooth regular wall:
 Colloid accumulation in goiter = colloid-filled dilated macrofollicle
 Simple cyst (extremely uncommon)
 Solid particles + irregular outline:
 Hemorrhagic colloid nodule
 Hemorrhagic adenoma (30%)
 Necrotic papillary cancer (15%)
 Liquefaction necrosis in adenoma / goiter
 Abscess
 Cystic parathyroid tumor
 bloody fluid = benign / malignant lesion
 clear amber fluid = benign lesion
 Cystic lesions often yield insufficient numbers of cells!
Dr Ahmed Esawy

47. HYPOTHYRIODISM
CONGENITAL
Hypoplasia & mal-descent
Agenesis ,hemiagenesis
Ectopia thyriod (sublingual thyriod)
Familial enzyme defects
Iodine deficiency (endemic cretinism)
Intake of goitrogens during pregnancy
Pituitary defects
Idiopathic Iodine deficiency(diffuse giotre)
Hashimoto´s thyroiditis (autoimmune thyroiditis)
Subacute (De Quervein’s) thyroiditis
Thyroidectomy or RAI therapy
TSH or TRH deficiency
Medications (iodide & Cobalt,amiodarone))
Idiopathic
Post partum
amyliodosis
ACQUIRED
Dr Ahmed Esawy

48. INCREASE
THYRIOD HORMONE
Thyrotoxicosis refers to
the manifestation of
excessive quantities of
circulating thyroid
hormone
Hyperthyroidism refers only to the
subset of thyrotoxic diseases caused
by the overproduction of the thyroid
hormone by the gland itself.
Dr Ahmed Esawy

49. HYPERTHYROIDISM
ETIOLOGY
• Graves’ disease ( autoimmune ).
• Toxic multi-nodular goiter ( toxic MNG ).
• Toxic nodule (hot or warm nodule)
Dr Ahmed Esawy

50. COMMON CAUSES OF HYPERTHYROIDISM
 autoimmune diseases
Graves disease (the most common cause of
hyperthyroidism
Lymphocytic thyroiditisWith hyperthyroidism
(silent thyroiditis)
Postpartum thyrotoxicosis (PPT)
 functioning thyroid adenomas (Hyperfunctioning thyroid
nodules (toxic adenoma, toxic multinodular goiter,
Plummer's disease)
 Toxic multinodular goiter
Dr Ahmed Esawy

51. High blood levels of thyroid hormones
(hyperthyroxinemia)
 Inflammation of the thyroid (thyroiditis).
(subacute thyrioditis) (DeQuervain's) and Hashimoto's thyroiditis (Hypothyroidism immune-
mediated),These may be initially associated with secretion of excess thyroid hormone, but
usually progress to gland dysfunction and, thus, to hormone deficiency and hypothyroidism.
 Oral consumption of excess thyroid hormone tablets
 Amiodarone, an antiarrhythmic drug,
 Postpartum thyroiditis (PPT)
 A struma ovarii is a rare form of monodermal teratoma that contains mostly
thyroid tissue
 Excess iodine consumption notably from algae such as kelp.
 Hypersecretion of thyroid stimulating hormone (TSH), which in turn is
almost always caused by a pituitary adenoma
 Thyroid tumor. A noncancerous thyroid tumor may make and secrete
increased amounts of thyroid hormones.
LESS COMMON CAUSES OF THYROTOXICOSIS
HYPERTHYROIDISM
Dr Ahmed Esawy

52. Varieties of
Thyrotoxicosis
 Associated with
thyroid
hyperfunction:
 Excess production of
TSH(rare)
 Abnormal thyroid
stimulator-Eg:Graves’
disease
 Intrinsic thyroid
autonomy-
Eg:Hyperfunctioning
adenoma,Toxic
multinodular goitre
 Not associated with
thyroid hyperfunction:
 Disorders of hormone
storage-Eg:Subacute
thyroiditis, chronic
thyroiditis
 Extrathyroid source of
hormone-Thyrotoxicosis
factitia,ectopic thyroid
tissue- struma ovarii,
functioning follicular Ca.
Dr Ahmed Esawy

53. DEVELOPMENTAL ABNORMALITIES
OF
THYROID GLAND
Dr Ahmed Esawy

54. developmental process of the thyroid gland during the embryonic period. Descent of the
thyroid gland during embryological development can be visualized from the thyroglossal duct
cyst or remnant/ectopic tissue to its ultimate position, in the pretracheal regionDr Ahmed Esawy

55. Hemiagenesis of the thyroid gland. Axial contrast-enhanced
CT scan demonstrates absence of the left lobe, which is a
typical finding in hemiagenesis.
Dr Ahmed Esawy

56.  Right lobe is enlarged, with mixed echogenic mass
(arrows). Fine-needle aspiration was consistent with
adenoma.
Thyroid Hemiagenesis with Adenoma
Dr Ahmed Esawy

57.  CT scan obtained 9 months before sonogram shows
absent left thryoid lobe and enlarged right thryoid lobe
with small low-attenuation lesion (arrows).
Dr Ahmed Esawy

58. A 44-yearold woman with midline thyroid remnant tissue.Contrast-
enhanced CT image (a) shows a small, strongly enhanced mass between the strap
muscles at the anterior aperture of the thyroid cartilage (arrows). The thyroid gland
has a normal appearance in the lower neck (b).
Dr Ahmed Esawy

59. a–d. A 39-year-old woman with midline thyroid remnant tissue.T1- (a) andT2-weighted (b)
MR images show a superficial lesion with intermediate signal intensity in the right paramedian
region, at the anterior aperture of the thyroid cartilage (arrows). Contrast-enhancedT1-
weighted MR images (c, d) show strong homogeneous enhancement of the mass (c, arrows).
This lesion has the same signal intensity and enhancement pattern as the thyroid gland in all
sequences. Dr Ahmed Esawy

60. a–c. A 35-year-old man with midline ectopic
thyroid tissue. Contrastenhanced
CT image (a) shows round, enhanced ectopic
thyroid tissue at the anterior aperture of the
thyroid cartilage (arrows).The thyroid gland is
located in the normal location; however,
agenesis of the isthmus with hypoplastic
thyroid lobes exists (b, asterisk).An image of
the I-131 scan (c) illustrates a
well-defined area of uptake nearly at the hyoid
bone, located at the midline (arrows).
Dr Ahmed Esawy

61. a, b. A 42-year-old man with lateral ectopic thyroid tissue. Contrast-enhanced CT images
(a, b) show ectopic thyroid tissue in the submandibular and parapharyngeal regions at the
hyoid bone level.The left submandibular gland is pushed anterolaterally by the ectopic
tissue (a, arrows).The right thyroid lobe is visualized in the normal location and incidentally
detected as a hypodense nodule in the right lobe. Agenesis of the isthmus and left thyroid
lobe is noted (b).
Dr Ahmed Esawy

62. A 59-year-old man with lateral ectopic thyroid tissue. Contrast-enhanced CT image series
show a homogeneous, dumbbell-shaped mass with uniform enhancement that extends into
the submandibular region from the left thyroid lobe region. No isthmus is present
Dr Ahmed Esawy

63. Lingual thyroid
Dr Ahmed Esawy

64. 34-year-old man with a thyroglossal duct cyst. Contrast-enhanced CT image
shows a cystic mass in the anterior midline of the neck, at the level of the thyroid
cartilage (arrows). The cyst contains thin septations. Histopathological examination
revealed a thyroglossal duct cyst.
Dr Ahmed Esawy

65. Thyroglossal duct cyst. A cystic left mass (asterisk)
embedded within the paralaryngeal strap muscles onT1-
weighted MR image.The fluid is mildly hyperintense; the
subcutaneous fat is normal. Dr Ahmed Esawy

66. Thyroglossal duct cyst. Enhanced CT (A) shows a hypodense
left neck lesion (asterisk) located within the paralaryngeal strap
muscles (m).This appearance resembles a "snake swallowing
an egg" (B).Thyroglossal duct cyst (asterisk), strap muscles (m).Dr Ahmed Esawy

67. Thyroglossal duct cyst. Enhanced CT at level of hyoid bone (A)
shows a lateral cystic lesion (asterisk) notching the inner surface of
the hyoid (arrow). Inferiorly at the level of the pyriform sinuses (B),
the lesion (asterisk) is embedded in the paralaryngeal strap muscles
(m).
Dr Ahmed Esawy

68. Thyroglossal duct cyst. Enhanced CT at level of hyoid bone
shows a lateral cystic lesion (asterisk) notching the inner
surface of the hyoid (arrow). Inferiorly at the level of the
pyriform sinuses (B), the lesion (asterisk) is embedded in the
paralaryngeal strap muscles (m).
Dr Ahmed Esawy

69. Thyroglossal duct cyst.T1-weighted MR image
demonstrating a mildly hyperintense midline lesion (arrow)
notching the dorsal surface of the hyoid bone (arrowheads).Dr Ahmed Esawy

70. a–d. A 48-year-old woman
with a giant thyroglossal duct cyst.
Axial
T1-weighted MR image (a) shows a
well-defined cystic mass in the floor of
the mouth at the tongue base, the
classic location for a thyroglossal duct
cyst.The increased signal intensity of the
cyst is due to either proteinaceous
content or a prior hemorrhage (a,
arrows). CoronalT2-weighted MR image
(b) reveals high hyperintensity of the
cyst, with mural thickening (arrows).
The axial (c) and sagittal (d)
contrast-enhancedT1-weighted
MR images with fat
suppression show mild rim
enhancement of the cyst with
strong enhancement of
the thickened wall due to residual
thyroid tissue (arrows).
Dr Ahmed Esawy

71. Pyramidal lobe. Axial contrast-enhanced CT scan shows persistence of the distal portion of
the thyroglossal duct.This condition is present in 50% of the population. P = pyramidal lobe.
Dr Ahmed Esawy