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Thyroid image reporting and data system (TIRADS)

Thyroid image reporting and data system (TIRADS)

Dr Rupesh Namdev and Dr Praveen Jha et al.



TIRADS classification system is being advocated similar to BIRADS category for breast lesions. Although not accepted globally, it may help radiologists in classifying and risk stratification of thyroid lesions.



Classification system has been proposed by Horvath et al1, with a modified recommendation from Jin Kwak et al2.



Similar to BIRADS category, sonographic TIRADS classification is as follows-



TIRADS 1 - normal thyroid gland

TIRADS 2 - benign lesions

TIRADS 3 - probably benign lesions

TIRADS 4 - suspicious lesions (subclassified as 4a, 4b, and later 4c 2 with increasing risk of malignancy)

TIRADS 5 - probably malignant lesions (more than 80% risk of malignancy)

TIRADS 6 - biopsy proven malignancy

TIRADS 2 category



avascular anechoic lesion with echogenic specks (colloid type I)

vascular heteroechoic non-expansile, non-encapsulated nodules with peripheral halo (colloid type II)

isoechoic or heteroechoic, non-encapsulated, expansile vascular nodules (colloid type III)

These conditions have 0% risk of malignancy.



TIRADS 3 category



hyperechoic, iso-echoic or hypoechoic nodules, with partially formed capsule and peripheral vascularity, usually in setting of Hashimoto's thyroiditis (Hashimoto's pseudonodule)

Modified TIRADS classification2 have simplified TIRADS 3 category as none of the suspicious malignant sonographic features described below. These lesions are mostly benign with <5% risk of malignancy1.



TIRADS 4 and 5 categories



These categories are based on five suspicuous sonographic features of malignancy



solid component

markedly hypoechoic nodule

microlobulations or irregular margins

microcalcifications

taller-than-wider shape

TIRADS 4a - one suspicious feature

TIRADS 4b - two suspicious features

TIRADS 4c - 3-4 suspicious features

TIRADS 5 - all five suspicious features

TIRADS 4a has 5-10% risk of malignancy, 4b and 4c may have 10-80% risk of malignancy. TIRADS 5 category lesion have >80% risk of malignancy1.



http://radiopaedia.org/articles/thyroid-image-reporing-and-data-system-tirads