Thyroid ultrasound versus antithyroid peroxidase antibody determination: a cohort study of four hundred fifty-one subjects

• Published in: Thyroid (New York, N.Y.) Vol. 12; no. 8; p. 725
• Main Authors: Raber, Wolfgang, Gessl, Alois, Nowotny, Peter, Vierhapper, Heinrich
• Format: Journal Article
• Language: English
• Published: United States 01-08-2002
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Autoantibodies - analysis; Cohort Studies; Female; Humans; Hyperthyroidism - diagnostic imaging; Hyperthyroidism - immunology; Hypothyroidism - diagnostic imaging; Hypothyroidism - immunology; Iodide Peroxidase - immunology; Male; Middle Aged; Predictive Value of Tests; Sensitivity and Specificity; Thyroid Gland - diagnostic imaging; Thyroiditis, Autoimmune - diagnostic imaging; Thyroiditis, Autoimmune - immunology; Ultrasonography
• ISSN: 1050-7256
• DOI: 10.1089/105072502760258712

Autoimmune thyroiditis is mirrored by a hypoechoic ultrasound pattern. We determined diagnostic precision of thyroid sonography compared to that of anti-thyroid peroxidase antibody (TPOAb) concentration. Ambulatory patients with unknown thyroid status (n = 451; 407 female, ages 44 +/- 16 years; 45 male, ages 50 +/- 14 years) excluding those with suspected hyperthyroidism or on drugs known to cause hypothyroidism were recruited consecutively. Subjects were recruited from a specialized thyroid outpatient unit with higher frequencies of thyroid disorders than in the general population. Before determination of thyroid function and TPOAb concentration thyroid volume (normal values: women < 12 mL, men < 14 mL) and echogenicity (grade 1 = normal: similar to submandibular gland, hyperechoic to neck muscles; grade 2: hypoechoic to submandibular gland, hyperechoic to neck muscles, grade 3: iso-/hypoechoic to neck muscles) were determined. Positive predictive value of grade 3 pattern for detection of autoimmune thyroiditis was 94% (with overt hypothyroidism) and 96% (with any degree of hypothyroidism), that of grade 2 or 3 85% and 87%, respectively. Negative predictive value of grade 1 pattern for detection of euthyroid TPOAb negative subjects was 91%. Goiter was present in 31% and 21% of TPOAb postive and negative subjects, respectively, while 11% and 15% had an atrophic thyroid gland (p = not significant [n.s.]). Given a high intraobserver and interobserver agreement abnormal thyroid ultrasound patterns were highly indicative of autoimmune thyroiditis and allowed the detection of thyroid dysfunction with 96% probability.