Affiliations: Department of Radiology, the First Affiliated Hospital
of Anhui Medical University, Hefei, Anhui, China | GE China CT Research Center, Beijing, China
Note: [] Corresponding author: Bin Liu, Department of Radiology, the
First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui,
China. Tel.: +86 15375330581; E-mail: liubin1305@126.com
Abstract: OBJECTIVE: To quantitatively evaluate the diagnostic value of
gemstone spectral CT in thyroid disease. PATIENTS and METHODS: A total of 123 patients with thyroid diseases were enrolled in the retrospective study.
All the patients underwent spectral CT scan, and 39 of them underwent
dual-phase enhanced scan. Iodine concentration (IC) and normalized IC (NIC)
were compared between benign and malignant nodules. The optimal threshold to
predict malignancy was obtained by receiver operating characteristic curve
(ROC). Multivariate ROC analysis was performed to evaluate the efficacy of
combining the IC (NIC) and conventional morphological characteristics. RESULTS: Ten diffuse diseases and 113 nodular diseases were confirmed by
clinical laboratory examination and histopathology. In total, 122 nodules (87
benign and 35 malignant) were detected, 41 nodules in enhanced cases. The IC
and NIC_{VP} of malignant nodules were significantly lower than benign
nodules in noncontrast and venous phase (VP) (P=0.000). The optimal IC and
NIC_{VP} threshold was 0.68 mg/mL and 0.38, achieving 74.3% and
76.9% sensitivity, 66.7% and 80.0% specificity, respectively. For
multivariate analysis, the area under ROC (AUC) was 0.88 and 0.94 in
noncontrast and VP, respectively. Sensitivities of 77.1% and 84.6%, and
specificities of 84.5% and 88.0% were achieved. CONCLUSION: Gemstone spectral CT can generally evaluate the abnormal iodine content in
thyroid disease. Lower iodine can help differentiating malignant from benign
nodules. A comprehensive analysis combining spectrum parameters and
morphological characteristics is suggested in differential diagnosis.
