Quantitative Tissue Elasticity Imaging for the Evaluation of Thyroid Nodules Coexistent with Autoimmune Thyroid Disease

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 471-496-Thyroid Neoplasia & Case Reports
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-491
Shoichiro Izawa*1, Kazuhiko Matsuzawa1, Yoshiyuki Adachi2, Mari Miyagi2, Miho Fujiyama2, Tsuyoshi Ohkura1, Hiroko Ohkura1, Akio Yoshida3, Masahiko Kato1, Shin-ichi Taniguchi1 and Kazuhiro Yamamoto1
1Tottori University Faculty of Medicine, Yonago, Japan, 2Tottori University Hospital, Yonago, Japan, 3Tottori University Graduate School of Medicine, Yonago, Japan
Objectives: Elastography is an evolving technique aimed at differentiating benign from malignant thyroid nodules. This technique allows in vivo estimation of the tissue mechanical properties using a conventional ultrasound (C-US) system with modified software. Virtual Touch Tissue Quantification (VTTQ) is a new imaging modality equipped with ACUSON S2000 (SIEMENS) for analyzing the tissue stiffness, and is evaluated by a 9 MHz linear US transducer operated with no added pressure. Its value is relatively reproducible and not influenced by the stiffness of surroundings and operator. We evaluated the value of VTTQ for thyroid nodule (TN) coexistent with autoimmune thyroid disease (AITD).

Patients and Methods: We enrolled 205 patients admitted to Tottori University Hospital for complaining of thyroid nodules or thyroid dysfunction from November 2011 to June 2012. C-US pattern and VTTQ were evaluated by 3 technicians and 2 doctors not informed of medical records and laboratory findings. AITD was defined by at least 2 of the following 3 conventional US manifestations generated by 14 MHz transducer.

  1. diffuse low echogenity
  2. increased blood flow signal
  3. diffuse goiter

All patients were evaluated in supine position with dorsal flexion of the head. VTTQ of each lobe was measured in line with the longest diameter. VTTQ was calculated 3 times on each position and average value was enrolled for the analysis. The values were expressed as meters/second (m/s). Odds ratio (OR) was adjusted for sex, age, and body mass index.

Results: The C-US manifestation of AITD was observed in 102 patients. The positivity of autoantibodies, hypothyroidism, and hyperthyroidism was significantly higher in AITD (p<0.01). The average VTTQ was significantly higher in patients with AITD than those without AITD (2.21 m/s vs. 2.03 m/s, p<0.01). The value of VTTQ (OR 2.27, 95% CI 1.13-4.60, p=0.02) was associated with the C-US manifestation of AITD. However, the OR was smaller than that of TgAb positive (7.03, 2.88-17.13, p<0.01) and TPOAb positive (34.07, 7.35-157.83, p<0.01). Cytologically benign TNs were observed in 56 patients (18 with AITD and 38 without AITD) by C-US. The average value of TNs coexistent with AITD was similar to that without AITD (2.17m/s vs. 2.03 m/s, p=0.59).

Conclusion: The value of VTTQ is associated with the presence of AITD, though the diagnostic power is not superior to thyroid autoantibodies. Our data indicate that the value of VTTQ is feasible for evaluating the stiffness of TNs, and not influenced by the surroundings like AITD.

Nothing to Disclose: SI, KM, YA, MM, MF, TO, HO, AY, MK, SIT, KY

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm