1. Radiological imaging of thyroid diseases.
PG STUDENT - DR. SAGAR M RAUL.
UNDER THE GUIDANCE OF
DR. RAJESH UMAP SIR,
ASSOCIATE PROFESSOR,
DEPT OF RADIOLOGY,
BJGMC AND SGH PUNE.

2. METS HYPERPLASTIC LYMPHOMA NODULAR ADENOMA CARCINOMA Iso/hyperechoic
hypoechoic-honey
coomb
Thin peripheral halo
Peri & intranodular
vascula.
ADENOMA
Hyper/iso/hypoechoic
Thick peripheral halo
Spoke wheel
Appearance
LYMPHOMA
Elder
NHL
Dyspnoea,Dysphagia
Hashimoto’s thyroditis
Hypoechoic nd lobular
Hypovascular/chaotic
vasc.
encasement
METS
Homogenous
Hypoechoic
No calcification
Primary-
Rcc/breast/
Melanoma
CARCINOMA
PAPILARY
3RD,7TH Decade
Psammoma bodies
Cervical LN
HYPOECHOIC
PUNCTATE
CALCIFICATION
Disorganised
hypervascularity
Cystic LN Mets
FOLLICULAR
Hyperechoic
Thick irregular
halo
Tortous vessels
Hematogenous
spread To
Bone/lung/
brain/liver
MEDULARY
Famillial
MEN type-2
Calcitonnin
LN METS-HIGH
HYPOECHOIC
COARSE
CALCIFICA
ANAPLASTIC
Elder
Aggressive
Invasion=
muscles,vessels
Worst prognosis

3. Normal ultrasound anatomy of thyroid
It is located anterior and lateral to trachea below the level of thyroid cartilage and above the sternal notch. (infrahyoid compartment)
DIVISION :
RIGHT AND LEFT LOBES,
ISTHMUS
PYRAMIDAL LOBE (10-40 %)

5. The superior thyroid Vessels are found at upper pole of each lobe and inferior thyroid vein is found at lower pole whereas the inferior thyroid artery is located posterior to lower third of each lobe.

7. NORMAL DIMENSIONS OF THYROID LOBES
A-P LENGTH
NEWBORN mm mm
INFANT mm mm
ADULT mm mm
Normal Mean Thyroid Volume (LxWxTHICKNESSx0.52) :
MALE-UPTO 23gm IS NORMAL
FEMALE- UPTO 22gm IS NORMAL.
Mean thickness of isthmus – 4 to 6mm
A-P diameter is most precise because relatively independent of possible dimensional asymemetry between two lobes.
When AP diameter- > 2cm --- Enlarged gland.

8. EMBRYOLOGY
Thyroid gland is originated from epithelial cells of floor of pharynx.
It descends from pharynx & remains connected to pharynx through a tract,known as thyroglossal duct.
The gland reaches to its normal location by 7 weeks of gestational age.
Then after duct involutes.

10. CONGENITAL ABNORMALITIES
AGENESIS/HYPOPLASIA OF THYROID
ECTOPIC THYROID

11. USG : Abnormal echogenic tissue in the expected location of the thyroid, without any normal flow on color Doppler imaging. There is no evidence of ectopic thyroid tissue.
THYROID AGENESIS

13. ECTOPIC THYROID The thyroid gland develops as a median angle from a diverticulum of the foramen cecum. Normally, it descends to its typical location anterior to the cervical trachea via the thyroglossal duct. Anomalies of descent can lead to a lingual or sublingual position of the gland. Nuclear medicine scintigraphy with sodium iodine-123 or pertechnetate-99m is used to evaluate the neck for the presence of thyroid tissue. Diagnosis of lingual thyroid is made when uptake is seen at the tongue base but not in the thyroid bed. Further evaluation can be done using CT & MRI imaging.

14. CT image- round mass at tongue base which enhances after contrast administration.  A pertechnetate-99m scan shows uptake corresponding to mass at tongue base without uptake in the thyroid bed. 

15. Thyroid disorders Thyroid disorders can be divided into
Nodular thyroid disease
Diffuse thyroid disease.

16. Nodular thyroid disease
Hyperplasia and goiter
Adenoma
Carcinoma
Lymphoma
Metastases

17. Hyperplasia and Goiter:
Etiology:
Iodine deficiency, dishormonogenesis (familial),poor utilization of Iodine.
F:M-3:1 ,more between years.
When hyperplasia leads to an overall increase in size or volume of the gland it is called as GOITER.
Hyperplastic nodules often undergo liquefactive degeneration with the accumulation of blood, serous fluid and colloid substance, referred to as hyperplastic,adenomatous, or colloid nodules.
Coarse and perinodular calcification occur.

18. HYPERPLASIA AND GOITER
Sonography
Most   hyper plastic or adenomatous nodules are isoechoic compared to normal thyroid tissue.
As Size of the mass increases, it may become hyperechoic.
Less frequently hypo echoic sponge—like or honey coomb cystic pattern is seen.
When nodule is hyperechoic or isoechoic, a thin peripheral hypoechoic halo is commonly seen-due to perinodular blood vessels and edema or compression of adjacent normal parenchyma.
Perinodular, intranodular vascularity on colour Doppler.
DEGENERATIVE CHANGES:
Purely anechoic -due to serous/colloid fluid.
Echogenic fluid/moving fluid-fluid levels due to hemorrhage.
Bright echogenic foci with comet tail artifacts due to dense colloid material/microcrystals.
Eggshell(thin peripheral) or coarse calcification.

21. Sagittal image of predominantly cystic nodule (calipers), which proved to be benign at cytologic examination.
Sagittal image of predominantly
solid nodule , which proved to be
benign at cytologic examination.

22. Transverse US images of mostly cystic thyroid nodule with a mural component containing flow. (a) Gray-scale image shows predominantly cystic nodule with small solid-appearing mural component (b) Addition of color Doppler mode demonstrates flow within mural component , confirming that it is tissue and not debris. US-guided FNA can be directed into this area. The lesion was benign at cytologic examination.

25. FOLLICULAR ADENOMA Sonography F:M – 7:1
Solitary or as a part of multi nodular goiter.
Sonography
Hyperechoic, iso or hypoechoic solid masses .
Have Peripheral hypoechoic halo which is thick & smooth- due to fibrous capsule and blood vessels.
Typical spoke and wheel type of appearance on color doppler.
D/D : FOLLICULAR CARCINOMA— where vascular and capsular invasion are hallmarks.

27. FOLLICULAR ADENOMA

30. Thyroid Carcinoma: Papillary cancer 3rd and 7th decade. F>M
The major route of spread is through lymphatics to nearby cervical lymph nodes.
Distant metastasis is rare (2-3%) and occurs to mediastinum and lungs.
HISTOLOGY: PSAMMOMA BODIES

33. Role of color Doppler US. (a) Transverse gray-scale image of
Predominantly solid thyroid nodule (b) Addition of color Doppler modeshows marked internal vascularity,indicating increased likelihood
that nodule is malignant. This was a papillary carcinoma.

34. Malignant Benign
Punctate echogenicities in thyroid nodules. (a) Sagittal US image of nodule containing multiple fine echogenicities with no comet-tail artifact. These are highly suggestive of malignancy.FNA and surgery confirmed papillary carcinoma. (b) Transverse US image of nodule containing cystic areas with punctate echogenicities and comet-tail artifact consistent with colloid crystals in a benign nodule.

37. Follicular variant of papillary ca of thyroid:- 10% cases of Papillary Ca. Similar to Follicular Ca on ultrasound and gross pathology. Microscopic studies show nuclear features of Papillary Ca. Clinical course and treatment are same as Papillary Ca. Papillary Microcarcinoma:- Rare, non encapsulated sclerosing tumor measuring less than 1.0 cm. Pt present with enlarged cervical LN with palpably normal gland. Nodules have hyper echoic fibrotic patches with no visible micro calcifications.

38. Follicular Carcinoma 5 -15% of thyroid neoplasms.
Hematogenous spread to bone/lung/brain/liver.
Sonography:
Cant be differentiated from follicular adenoma
So treatment for both is surgical excision.
Hypoechoic nodule with irregular tumor margins
Thick, irregular halo.
Tortuous or chaotic arrangement of internal blood vessels on color doppler.
PATHOLOGY: Vascular & capsular invasion.
WIDELY INVASIVE FORM
MINIMALLY INVASIVE FORM
-Not well encapsulated
-Invasion of vessels and adjacent thyroid is more easily demonstrated.
-Metastasis is in 20-40% cases
Well encapsulated
No gross invasion seen. Only focal histologic invasion noted.
5-10% cases.

42. Medullary Carcinoma Sonography only 5 % thyroid cancer.
Derived from parafollicular or C cells
secretes calcitonin.- useful serum marker.
Frequently familial and Associated with MEN II syndrome.
Bilateral in 90% of familial cases.
High incidence of metastatic to lymphnodes.
Sonography
- Similar to papillary carcinoma- hypoechoic solid mass with calcifications(often, but coarse than papillary carcinoma).
-Local invasion and cervical lymphadenopathy are also more common.

46. Sonography Anaplastic thyroid carcinoma Occurs in elderly
< 5% tumors
WORST prognosis
Presents as a rapidly enlarging mass extending beyond gland and invading adjacent structures.
Show aggressive local invasion of muscle and vessels.
Sonography
Hypoechoic masses often seen to encase or invade blood vessel and neck muscles
(CT or MRI demonstrates the tumor more accurately owing to their large size) .

48. Aggressive thyroid cancer in left neck with spread to lungs

49. Lymphoma 4% of all thyroid malignancies. Mostly non-Hodgkin’s type
Elder females
In 70-80% cases arises from pre-existing chronic lymphocytic thyroiditis(HASHIMOTO’S thyroiditis) with subclinical or overt hypothyroidism.
Sonography
Markedly Hypoechoic lobulated mass .
Hypovascular or show blood vessels with chaotic distribution and arteriovenous shunts.
Large areas of cystic necrosis may occur as well as encasement of adjacent neck vessels.
Adjacent thyroid parenchyma heterogenous due to associated chronic thyroiditis.

51. Isotope scan of thyroid demonstrating a photopenic area within the left lobe.
Axial contrast enhanced CT of the same patient shows a solid mass within left lobe of thyroid . Lymphoma was proven by biopsy.

52. METASTASIS TO THYROID GLAND RARE THROUGH HAEMATOGENOUS SPREAD SOLITARY WELL CIRCUMSCRIBED HYPOECHOIC NODULES WITH OR WITHOUT CALCIFICATIONS MELANOMA (39%) BREAST CA (21%) RENAL CELL CA (10%)

54. Differentiation Internal contents Echogenicity Feature Benign
malignant
Internal contents
Purely cystic
Cystic with thin septae
Mixed solid and cystic
Comet tail artifact
++++
+++ + ++
Echogenicity
Hyperechoic
Isoechoic
Hypoechoic

55. Halo Margins Calcification Feature Benign Malignant Thin
Thick incomplete
++++ + ++
+++
Margins
Well defined
Poorly defined
Calcification
Eggshell
Coarse calcification
Microcalcification

56. Doppler + rare (<1%) ++ low probability (<15%)
Feature
Benign
Malignant
Doppler
Peripheral flow
Internal flow
+++ ++
+ rare (<1%)
++ low probability (<15%)
+++ intermediate probability(16 to 84%)
++++ high probability (>85%)

57. METS HYPERPLASTIC LYMPHOMA NODULAR ADENOMA CARCINOMA Iso/hyperechoic
hypoechoic-honey
coomb
Thin peripheral halo
Peri & intranodular
vascula.
ADENOMA
Hyper/iso/hypoechoic
Thick peripheral halo
Spoke wheel
Appearance
LYMPHOMA
Elder
NHL
Dyspnoea,Dysphagia
Hashimoto’s thyroditis
Hypoechoic nd lobular
Hypovascular/chaotic
vasc.
encasement
METS
Homogenous
Hypoechoic
No calcification
Primary-
Rcc/breast/
Melanoma
CARCINOMA
PAPILARY
3RD,7TH Decade
Psammoma bodies
Cervical LN
HYPOECHOIC
PUNCTATE
CALCIFICATION
Disorganised
hypervascularity
Cystic LN Mets
FOLLICULAR
Hyperechoic
Thick irregular
halo
Tortous vessels
Hematogenous
spread To
Bone/lung/
brain/liver
MEDULARY
Famillial
MEN type-2
Calcitonnin
LN METS-HIGH
HYPOECHOIC
COARSE
CALCIFICA
ANAPLASTIC
Elder
Aggressive
Invasion=
muscles,vessels
Worst prognosis

58. Evaluation of nodules incidentally detected by sonography
Nodules <1.5cm : follow up by palpation at time of next physical examinaton
Nodules > 1.5cm : evaluation usually by FNA
Any nodule with malignant features like–microcalcifications, irregular margin , thick halo , or internal flow: FNA

59. Indications for Biopsy guidance
Nonpalpable suspected nodule with inconclusive physical examination.
Patients at high risk of developing thyroid cancer, normal gland by physical examination but sonography demonstrates a nodule.
Previous non diagnostic / inconclusive biopsy.

61. Diffuse Thyroid disease
Characterised by Generalized enlargement of gland and no palpable nodules.
Diagnosis is usually based on clinical and laboratory finding and occasion by FNA.
Sonography helpful when underlying disease causes asymmetric thyroid enlargement.
Sonographic diagnosis of diffuse thyroid disease is made when isthmus may be up to 1 cm or more thickness.

62. DIFFUSE THYROID DISEASE
1.THYROIDITIS
CHRONIC AUTOIMMUNE
LYMPHOCYTIC THYROIDITS
(HASHIMOTO’S THYROIDITIS)
ACUTE SUPPURATIVE
THYROIDITIS
INVASIVE
FIBROUS
THYROIDITIS
SUBACUTE GRANULOMATOUS
THYROIDITIS
(DE QUERVAIN’S DISEASE)
SILENT/
PAINLESS
THYROIDITIS
2.ADENOMATOUS OR COLLOID GOITRE
3. GRAVE’S DISEASE

63. ACUTE SUPPURATIVE THYRODITIS
Rare inflammatory disease caused by bacteria affecting children.
Sonography useful in selected cases to detect thyroid abscess.
Thyroid abscess:
Ill defined hypoechoic heterogenous mass with internal debris +/-- septa and gas.

64. SUBACUTE GRANULOMATOUS THYROIDITIS (DE QUERVAIN’S) Spontaneously remitting inflammatory disease probably caused by viral infection. C/F : fever, enlargement of gland ,Tenderness Sonography – Enlarged hypoechoic gland with normal or decreased vascularity due to edema.

66. Chronic autoimmune lymphocytic thyroiditis
Chronic autoimmune lymphocytic thyroiditis. (HASHIMOTO’S THYROIDITIS) Most common thyroiditis Young / middle aged woman F:M – 8 : 1 Painless diffuse enlargement of gland Often a/w hypothyroidism Autoimmune – Antibodies against Thyroglobulin or TPO.

67. Chronic autoimmune lymphocytic thyroiditis
Chronic autoimmune lymphocytic thyroiditis. (HASHIMOTO’S THYROIDITIS) USG :- Diffuse enlarged coarsened parenchymal echotexture Usually more hypoechoic than normal gland Vascularity : normal / decreased Occasionally hypervascular similar to thyroid inferno due to stimulation from high levels of TSH. Cervical LN present. In end stage, atrophy of gland heterogenous with absent blood flow. MICRONODULATION :- Multiple discrete hypoechoic nodules of 1-6 mm size strongly s/o chronic thyroiditis. Lobules of thyroid parenchyma are infiltrated by lymphocytes. These lobules are surrounded by multiple linear echogenic fibrous septations giving PSEUDO-LOBULATED APPEARANCE. Both benign and malignant nodules coexist. Increased risk of B – cell malignant lymphoma of thyroid gland. FNA biopsy is helpful.

71. Painless (silent) thyroiditis
Thyroid enlargement with hyperthyroidism occurs in early phase Followed by hypothyroidism.
Clinical findings are similar to subacute thyroiditis except tenderness
Histologic and sonographic pattern of chronic autoimmune thyroiditis.
Spontaneously remitts in 3-6 months

72. MULTINODULAR GOITRE

73. Graves disease
Diffuse abnormality of thyroid gland with associated hyperfunction (thyrotoxicosis ).
Sonography
Diffusely hypoechoic or inhomogenous texture
Color Doppler shows hypervascular pattern known as “thyroid inferno”.
Spectral Doppler shows peak velocities exceeding 70cm/sec.
No correlation with hypervascularity and lab (hormone) levels.
Significant decrease in flow velocities in thyroid vessels post treatment.

75. Graves disease.

76. Graves′ disease, the thyroid usually appears moderately enlarged with hypoechoic area inside.

77. Graves’ disease – diffuse hypervascularity and peak systolic velocity of 80cm\sec

78. Comparison between scans from the normal patient and a patient with Grave's disease. Note the overall increased uptake throughout the enlarged thyroid gland in the Grave's patient.

79. CT scans of the orbits show marked enlargement of the extra-ocular muscles with sparing of the tendons consistent with the ophthalmopathy seen with Grave's disease.

80. Proptosis with enlargement of the eye muscles and compression of the optic nerve in the left eye.

81. Voluminous thickening of all orbital muscles with oedematous changes, pathognomonic for active Graves’ orbitopathy with moderate to marked enhancement at the post-contrast study.

82. Invasive fibrous thyroiditis (Riedel’s struma)
Female
Rare
Tends to progress to complete destruction
USG
Diffusely enlarged thyroid gland
Inhomogenous parenchymal echo texture
May have associated mediastinal or retroperitoneal fibrosis or sclerosing cholangitis.
D/D : From Anaplastic thyroid carcinoma….by biopsy.

84. Role of CT and MRI in thyroid disorders
To demonstrate- Extent of local invasion
- regional LN metastasis
To determine recurrence following Surgery.
Detection of retrosternal & retrotracheal extension of the thyroid enlargement.
Confirm the location of mass within the gland, evaluating nodal disease and assessing the airway.

85. GOITER -Enhancing heterogenous soft tissue mass orignated in thyroid and causing deviation of the trachea
Large heterogenous soft tissue mass replacing the thyroid with speck of calcification,causing deviation of the trachea–medullary carci.

86. Cystic metastasis from thyroid carcinoma

87. CT signs suggesting the thyroid origin of mediastinal mass include
Intimate association of the superior pole of mass with thyroid gland & close proximity to the trachea.
Hyperdensity of lesion compared to surrounding tissue.
Presence of calcification.
Persistent enhancement of the mass.

88. Differentiation of benign and malignant primary thyroid masses is impossible on imaging, although the associated lymphadenopathy, vocal cord paralysis and bone or cartilage invasion obviously suggests malignancy.
MRI helps to differentiate scar from residual or recurrent tumor.
Tumor - hypointense to isointense on T1WI
iso to hyperintense on T2WI
scar - hypointense on both T1 and T2WI.

89. SONO ELASTOGRAPHY Newer non invasive technique
SONO ELASTOGRAPHY Newer non invasive technique. To diff b/w benign and malignant nodule. Select a portion of nodule having nodule. Acquire two images – Before & After tissue compression. Freehand compression -minimize inter/intraobserver variability. ELASTICITY SCORE / PATTERN. 1- WHOLE NODULE IS ELASTIC 2- LARGE PART OF NODULE IS ELASTIC 3- PERIPHERAL PART OF NODULE IS ELASTIC 4- UNIFORMLY ANELASTIC.

91. Thank you