Evaluation of the Relationship Between Resistive Index, Elastographic Stiffness, and TIRADS Category in Thyroid Nodules

Öz

Objective: To investigate the relationship between Doppler-derived resistive index(RI) values, TI-RADS categories, and shear-wave elastography(SWE) parameters in solid thyroid nodules, and to determine whether RI contributes additional value to imaging-based characterization. Material-Methods: This retrospective study included 52 patients with 52 solid thyroid nodules larger than 1 cm. All nodules were evaluated with grayscale ultrasonography, Doppler sonography, and SWE. TI-RADS categories were assigned according to standard B-mode criteria. Vascularity was classified into four Doppler patterns, and RI was measured from intranodular arterial flow in nodules exhibiting pattern 2 or 3 vascularization. SWE measurements included mean shear-wave velocity(Vmean) and velocity standard deviation(Vsd). Associations between RI and demographic(age,sex), morphologic(nodule size,TI-RADS),and elastographic(Vmean,Vsd) variables were analyzed using correlation and nonparametric tests. Histopathology was available only in a limited subgroup and was therefore not used as a primary endpoint. Results: The mean age was 49.28±14.55 years; 88.5% of patients were male. TI-RADS categories were TI-RADS 2 in 19 nodules(36.5%), TI-RADS 3 in 29 nodules(55.8%), and TI-RADS 4 in 4 nodules(7.7%). Mean nodule diameter was 17.06±6.63 mm. Vmean and Vsd were 2.47±0.86 m/s and 0.62±0.39 m/s, respectively. Mean RI was 0.52±0.14. RI showed no significant association with age, sex, nodule side, size, Vmean, or Vsd. Although RI values were slightly higher in TI-RADS≥3 nodules compared to lower TI-RADS categories, this difference was not statistically significant(p=0.054). Conclusion: In this preliminary cohort, RI was not significantly associated with TI-RADS classification or SWE-derived stiffness parameters. These findings suggest that RI offers limited additional diagnostic value beyond conventional ultrasonography and elastography in the structural evaluation of thyroid nodules.

Anahtar Kelimeler

• Shear wave elastography
• resistive index
• TIRADS
• Doppler sonography

Tiroid Nodüllerinde Rezistif İndeksi, Elastografik Sertlik ve TIRADS Kategorisi Arasındaki İlişkinin Değerlendirilmesi

Öz

Amaç: Bu çalışmanın amacı, solid tiroid nodüllerinde Doppler kaynaklı rezistif indeks(RI) değerleri ile TI-RADS kategorileri ve shear-wave elastografi(SWE) parametreleri arasındaki ilişkiyi araştırmak ve RI ölçümlerinin görüntüleme temelli karakterizasyon sürecine ek katkı sağlayıp sağlamadığını belirlemektir. Yöntemler: Bu retrospektif çalışmaya, çapı 1 cm’den büyük olan 52 solid tiroid nodülü bulunan 52 hasta dahil edildi. Tüm nodüller gri skala ultrasonografi, Doppler sonografi ve SWE ile değerlendirildi. TI-RADS sınıflaması standart B-mod kriterlerine göre yapıldı. Vaskülarite dört Doppler paterni şeklinde sınıflandırıldı ve RI ölçümü, patern 2 veya 3 intranodüler arteriyel akım gösteren nodüllerden elde edildi. SWE ölçümleri ortalama shear-wave hızı(Vmean) ve hız standart sapması(Vsd) parametrelerini içeriyordu. RI ile demografik(yaş, cinsiyet), morfolojik(nodül boyutu, TI-RADS) ve elastografik(Vmean, Vsd) değişkenler arasındaki ilişkiler korelasyon ve non-parametrik testler ile analiz edildi. Histopatolojik doğrulama yalnızca sınırlı bir alt grupta mevcut olduğundan birincil sonlanım noktası olarak kullanılmadı. Bulgular: Hastaların ortalama yaşı 49.28±14.55 yıl olup %88.5’i erkekti. TI-RADS dağılımı TI-RADS 2 için 19 nodül(%36.5), TI-RADS 3 için 29 nodül(%55.8) ve TI-RADS 4 için 4 nodül(%7.7) şeklindeydi. Ortalama nodül çapı 17.06±6.63 mm idi. Vmean ve Vsd sırasıyla 2.47±0.86 m/sn ve 0.62±0.39 m/sn olarak ölçüldü. Ortalama RI değeri 0.52±0.14 idi. RI; yaş, cinsiyet, nodül tarafı, nodül boyutu, Vmean veya Vsd ile anlamlı bir ilişki göstermedi.TI-RADS≥3 nodüllerde RI değerlerinin daha yüksek olması eğilimi izlense de bu fark istatistiksel olarak anlamlı değildi(p=0.054). Sonuç: Bu çalışmada RI değerleri ile TI-RADS sınıflaması veya SWE kaynaklı sertlik parametreleri arasında anlamlı bir ilişki saptanmadı. Bulgular, tiroid nodüllerinin yapısal değerlendirilmesinde RI’ın konvansiyonel ultrasonografi ve elastografi yöntemlerine ek sınırlı tanısal katkı sağladığını düşündürmektedir.

Anahtar Kelimeler

• Shear-wave elastografi
• rezistif indeks
• TI-RADS
• Doppler sonografi.

Kaynakça

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