MOB NO. 09978345496 ULTRASONOGRAPHY FEATURES OF NORMAL ANATOMY OF THYROID , CHARACTERISTICS OF VARIOUS NODULAR AND DIFFUSE THYROID DISEASES ( LESIONS )

1. ULTRASOUND IN THYROID LESIONS 1 DR RAJ BUMIYA First Year Resident Dept. of Radiodiagnosis S.S.G. Hospital, Baroda. 24/03/2011

2. Clinical applications of high resolution usg. Detection of thyroid and other cervical masses before and after thyroidectomy. 2. Differentiation of benign from malignant masses. Ultrasound detects the presence, size, site, number, characteristics of thyroid nodules . 3. FNA Guidance 2

3. Technique With high frequency transducer(7.5 to 15Mhz) Examination-supine position with neck extended. A small pad may be placed under the shoulders to provide better exposures of neck. Lower pole imaging is enhanced– by asking the pt. to swallow, so the gland moves upward. Examined thoroughly in transverse and longitudinal planes. 3

4. Multiple oblique and angled projections may be taken if necessary. Examined: SUPERIORLY: to identify Submandibularadenopathy INFERIORLY : to identify Supraclavicularadenopathy 4

6. ISTHMUS

7. PYRAMIDAL LOBE (10-40 %)5

8. 6 Normal thyroid parenchyma has homogenous medium to high level echogenicity & bounded by a thin hyperechoic line(the thyroid capsule). Landmarks to be identified: Midline -Trachea and oesophagus. Laterally- Common Carotid artery, IJV Anterolaterally:Strap muscles of the neck

9. 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

10. Anteriorly-Sternohyoid & omohyoid muscles, As hypoechoic bands. Lateral- Sternocleidomastoid As large oval band Posterior- Longus colli muscle Recurrent laryngeal nerve & inferior thyroid artery pass in the angle between trachea, oesophagus & thyroid lobe. On longitudinal scans, recurrent laryngeal nerve & inferior thyroid artery may be seen as hypoechoic bands between the thyroid lobe & oesophagus on left , thyroid lobe & longus colli on right. 8

11. Oesophagus – laterally & towards the left Target appearance on transverse plane Peristaltic movements On swallowing. Trachea Posteriorly Identified by lack of sound transmission and ring down artifacts. 9

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14. Inferior thyroid artery along the posterior surface 12 Inferior thyroid vein branches seen at the lower pole

15. NORMAL DIMENSIONS OF THYROID LOBES A-PLENGTH NEWBORN 8-9mm 18-20mm INFANT 12-15mm 25mm ADULT 13-18mm 40-60mm Normal Mean Thyroid Volume (LxWxTHICKNESSx0.52) : 18.6±4.5 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. 13

16. CONGENITAL ABNORMALITIES AGENESIS/HYPOPLASIA ECTOPIC 14

17. 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. 15

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19. 17 THYROID AGENESIS 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. Pertechnetatescintigraphy demonstrates no functioning thyroid tissue.

20. Sonography of the thyroid in this 1 yr. old female child revealed congenital absence of the entire thyroid. Note the empty fossae where the right and left lobes would normally lie. The carotid artery and jugular vein of both sides are seen in the color doppler images. These ultrasound and color doppler images suggest congenital agenesis of the thyroid. 18

21. ECTOPIC THYROIDThe 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. 19

22. 20 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.

23. Thyroid disorders Thyroid disorders can be divided into Nodular thyroid disease Diffuse thyroid disease. 21

24. Nodular thyroid disease Hyperplasia and goiter Adenoma Carcinoma Lymphoma Metastases 22

25. Hyperplasia and Goitre: Etiology: Iodine deficiency, dishormonogenesis(familial),poor utilization of Iodine. F:M-3:1 ,more between 35-50 years. Hyperplasia leads to an overall increase in size or volume of the gland. Hyperplastic nodules often undergo liquefactive degeneration with the accumulation of blood, serous fluid and colloid substance, reffered to as hyperplastic,adenomatous, or colloid nodules. Coarse and perinodular calcification occur. 23

26. 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. 24

27. 25 Sonogram of the left lobe of the thyroid gland in the transverse plane showing a rounded lobe of a goiter. L=enlarged lobe, I= widened isthmus,T=trachea,C=carotid artery,J=jugular vein, S=Sternocleidomastoid muscle, m=strap muscles, E=esophagus.

28. Hyperplastic nodules Oval homogenous isooechoic nodule with well defined peripheral halo. Multiple hyperechoic nodules 26

29. Cystic degenerative changes in adenomatous nodules 27

30. Adenoma F:M – 7:1 Solitary or as a part of multinodular 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. 28

31. Isoechoic solid mass with thick irregular complete halo. Power doppler – spoke and wheel like appearance FOLLICULAR ADENOMA 29

32. 30 multiple nodular densities in cervical region that are palpable on physical examination.CT scan obtained 9 months before sonogram shows absent left thryoid lobe and enlarged right thryoid lobe with small low-attenuation lesion.

33. Carcinoma: Most primary thyroid cancers are of epithelial origin and are derived from either the follicular or the parafollicularcells.Most are well differentiated. Papillary carcinoma- 75-90% . Medullary/Follicular/anaplastic car. -10-25% Papillary cancer 3rd and 7thdecade.F>M The major route of spread is through lymphaticsto nearby cervical lymph nodes. Distant metastasis is rare (2-3%) and occurs to mediastinum and lungs. HISTOLOGY: PSAMMOMA BODIES 31

34. Sonography Hypoechoic nodules with microcalcifications (tiny punctuate hyperechoic foci with or without acoustic shadowing). Disorganized hypervascularity on color doppler,Mostly in well encapsulated form. Cervical lymphnodemetatasis which may contain tiny punctateechogenic foci due to microcalcifications. Cystic lymph node metatasis in neck occur almost exclusively with papillary carcinoma. 32

35. Hypoechoic solid nodule with punctate calcification 33 Isoechoic nodule & punctateechogenic foci within it

36. Two rounded hypoechoic nodes – typical of metastasis to cervical nodes 34 Hetrogenous oval nodes containing microcalcifications

38. 36 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.

39. 37 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.

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41. Follicular Carcinoma 5 -15% (2 variants-widely invasive and minimally invasive) Hematogenousspread 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. 39

42. Heterogenous solid mass with peripheral and internal flow – follicular carcinoma 40

43. Medullary Carcinoma 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. 41

44. 42 Heterogenous nodule with multiple punctate foci of calcification within it – medullary carcinoma Isoechoic nodule & punctate echogenic foci within it

45. Longitudnal color and power doppler – intranodular hypervascularity 43

46. 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) . 44

47. Longitudnal scan – solid hypoechoic mass extending into the upper mediastinum – anaplastic carcinoma 45

48. 46 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. 47

50. Nodule within a cystic lesion. No flow within the nodule 48

51. 49 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. Differentiation 50

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54. + rare (<1%) ++ low probability (<15%) +++ intermediate probability(16 to 84%) ++++ high probability (>85%) 52

55. 53 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.

56. 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. 54

57. Peripheral coarsecalcification with acoustic shadowing – favours benign nature 55 Peripheral egg shell calcification

58. 56 HYPERPLASTIC NODULAR 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 Hypovascular/chaotic vasc. METS Homogenous Hypoechoic No calcification Primary-Rcc/breast/ Melanoma CARCINOMA PAPILARY 3RD,7TH Decade Psammoma bodies Cervical LN HYPERECHOIC 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

59. Evaluation of nodules incidentally detected by sonography Nodules<1.5cm : followed 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 57

61. Patients at high risk of developing thyroid cancer, normal gland by physical examination but sonography demonstrates a nodule.

62. Previous non diagnostic / inconclusive biopsy. 58

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65. 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

66. 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

67. Diffuse enlargement of the isthmus and both lobes 63 Diffuse enlargement – heterogenous gland with multiple nodules

68. ACUTE SUPPURATIVE THYRODITIS Rare inflammatory disease caused by bacteria affecting children. Sonography useful in selected cases to detect thyroid abscess-ill defined hypoechoic mass with debris and/or septa and gas. 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. 64

69. Ill defined hypoechoic area – focal area of subacutethyroiditisresolved after 4 wks of medical therapy 65

70. 66 Sagittal sonogram of left lobe of thyroid shows solid, predominately hyperechoic, poorly marginated nodule in lower pole corresponding to palpable abnormality.Fine-needle aspiration of this lesion was consistent with thyroiditis.Background of thyroid was heterogeneous,with geographic regions of hypoechogenicity.

71. Chronic autoimmune lymphocytic (Hashimoto’s) thyroiditis As a painless diffuse enlargement of thyroid often associated with hypothyroidism. genetic tendency . F:M – 8 : 1 .Young woman are affected. Lymphocytic infiltration of thyroid gland. Sonography Diffuse coarsened hypoechoic glandular enlargement 67

72. Multiple discrete hypoechoic micronodules of 1-6 mm size is strongly suggestive of chronicthyroiditis. Surrounded by multiple linear echogenic fibrous septations- giving pseudo lobulated appearance. Normal or hypovascular.Occasionallyhypervascular . Often Cervical lymphadenopathy may be present. In end stage, atrophy of gland occurs when thyroid gland is small with ill defined margins and heterogenousechotexture with absent blood flow. 68

73. Various appearances of Hashimoto’s disease 69

74. 70 Nodule was predominantly hyperechoic, with both solid and cystic-appearing Fine-needle aspiration of this 28 mm palpable nodule was consistent with lymphocytic thyroiditis.

75. Sagittal sonogram of right lobe obtained at time of diagnosis of left-sided thyroid carcinoma shows 11-mm hypoechoic solid nodule with ill-defined margins (delineated by electronic calipers) in upper pole of right lobe. Sonographically guided fine-needle aspiration of this nodule and surgical pathology findings were consistent with lymphocytic thyroiditis. 71

76. Painless thyroiditis Thyroid enlargement in early phase followed by hypothyroidism. Clinical findings are similar to subacutethyroiditis Histologic and sonographic pattern of chronic autoimmune thyroiditis. 72

77. Graves disease Diffuse abnormality of thyroid gland with associated thyrotoxicosis Sonography Diffusely hypoechoic or inhomogenous texture Color Doppler shows hypervascular pattern known as “thyroid inferno”. Spectral Doppler shows peak velocities exceeding 70cm/sec. 73

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79. 75 Graves’ disease – diffuse hypervascularity and peak systolic velocity of 80cmec

80. 76 Pinhole images from a Tc-99m pertechnetate thyroid exam demonstrate diffuse thyroid enlargement with decreased background activity.

81. Invasive fibrous thyroiditis(Riedel’s struma) Female Tends to progress to complete destruction USG Diffusely enlarged thyroid gland Inhomogenousparenchymal echo texture May have associated mediastinal or retroperitoneal fibrosis or sclerosingcholangitis. D/D : From Anaplastic thyroid carcinoma….by biopsy. 77

82. 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. 78

83. 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. 79

84. 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. 80

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86. GOITER -Enhancing heterogenous soft tissue mass orignated in thyroid and causing deviation of the trachea 82 Large heterogenous soft tissue mass replacing the thyroid with speck of calcification,causing deviation of the trachea–medullary carci.

87. Cystic metastasis from thyroid carcinoma 83

88. Role of radionuclide thyroid scintigraphy To determine functional status of the nodules. Nodules may be cold, warm or hot depending on the uptake of tracer as compared to the normal thyroid tissue. Thyroid nodules concentrate less radioiodine (only 1%) than normal thyroid tissue hence appear cold. Most cold nodules are adenomas, colloid nodules or foci of thyroiditis or rarely intrathyroid lymphnodes, lymphoma or metastases. 84

89. Approximately 10 to 20 % of cold solitary thyroid nodules are malignant. Cold nodules further require FNAC or biopsy. The demonstration of hot nodule on scintigraphy is not synonymous with autonomy, as it often represents spared focus of normal thyroid tissue in gland otherwise involved in destructive process. The more important role is of 131 I whole body scintigraphy to identify most functioning metastases, usually in the neck, lungs or bone, following total thyroidectomy. 85

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92. MCQs 88

93. 89 1. GIVE THE DIAGNOSIS

94. 2. Egg cell calcifications are more common in which type of tumor? 90

95. 91 3.Which type of carcinoma has such appearance ?

96. 92 4. GIVE THE DIAGNOSIS

97. 93 5.GIVE THE DIAGNOSIS

98. THANK YOU 94