title: CT-detected solitary thyroid calcification: an important imaging feature for papillary carcinoma.
abstract: OBJECTIVE
  To evaluate computed tomography (CT) detection of solitary thyroid calcification for identifying thyroid papillary carcinoma and to determine whether the predictive ability changes when the size increases after enhancement.
  
  
  METHODS
  CT scans on all 96 patients with thyroid nodules who underwent both enhanced CT examination of neck and thyroidectomy from 2014 to 2016 in the Shandong Cancer Hospital affiliated to Shandong University were reviewed. The cases without calcification and the cases with peripheral calcification, multiple coarse calcifications, or punctate calcification were excluded. Imaging features, including location and size of the lesions, were reviewed on plain and contrast-enhanced CT. The patients were grouped by histological results. The comparisons were evaluated by using Fisher's exact test and binary logistic regression.
  
  
  RESULTS
  The study population consisted of 96 patients (74 females, 22 males; mean age 49.8±11.3 years). Papillary thyroid carcinoma was observed in both solitary calcified thyroid nodules (85.4%) and solely coarse calcifications surrounded by low-density focus (58.2%). The difference was significant (P=0.006). Of 64 patients with an amplification of lesions after contrast enhancement, 58 (90.6%) were diagnosed with a malignant lesion. At the same time, of the 32 patients with no increase in size, 10 (31.2%) were diagnosed with carcinoma and 22 (68.8%) with nodular goiter. This difference was significant (P<0.001), and after binary logistic regression, increasing size was an independent risk factor for cancer.
  
  
  CONCLUSIONS
  Solitary calcified thyroid nodules detected on CT represent a high risk for papillary thyroid carcinoma, especially when the size of the lesions increases after contrast- enhanced CT.
authors: School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences; Department of Radiology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong Province, People's Republic of China.
authors: Tian-Tian
authors: TT
authors: Yang
authors: Department of Radiology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong Province, People's Republic of China.
authors: Yong
authors: Y
authors: Huang
authors: School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences; Department of Radiology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong Province, People's Republic of China.
authors: Xu-Quan
authors: XQ
authors: Jing
authors: School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences; Department of Radiology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong Province, People's Republic of China.
authors: Xiu-Juan
authors: XJ
authors: Gai
authors: Department of Radiology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong Province, People's Republic of China.
authors: Wen-Wu
authors: WW
authors: Li
keywords: computed tomography; papillary thyroid carcinoma; size; solitary calcified thyroid nodule