Initial quantitative analysis of gemstone spectral imaging CT: Analysis and discussion of the application value for the differentiation of small liver metastases (<3 cm).

BackgroundHepatic metastases are the most common malignant tumors in the liver. Conventional contrast-enhanced CT examinations face challenges in distinguishing between benign and malignant atypical metastatic liver lesions with a diameter <3 cm, and evaluating their therapeutic efficacy remains particularly difficult.ObjectiveTo assess the clinical value of quantitative iodine analysis and spectral curves for diagnosing and differentiating liver metastases using gemstone spectral CT.MethodsAmong 915 patients with suspected hepatic metastases, 140 cases (87 males, 53 females) were pathologically confirmed. Primary malignancies included colorectal cancer (41 cases), gastric cancer (21 cases), lung cancer (35 cases), pancreatic cancer (31 cases), and breast cancer (12 cases). A total of 425 small lesions (<3 cm) were detected. CT values at lesion centers and peripheries were measured and compared against normal liver parenchyma. Quantitative iodine concentrations and spectral curve slopes were analyzed to evaluate differences in small hepatic metastases originating from distinct primary malignanciesResultsIn the differentiation of hepatic metastatic subtypes, mean CT values demonstrated diagnostic utility in distinguishing colorectal cancer from gastric in AP (Arterial Phase, P = 0.001) in the Center of lesions.On the contrary, the quantitative analysis of focus edge iodine reliably distinguished the AP (P < 0.000), lung cancer (P = 0.023) and pancreatic cancer (P < 0.000) of colorectal cancer and gastric cancer. The results have statistical significance.ConclusionsGSI(Gemstone spectral Imaging)-derived spectral curve slope and quantitative iodine analysis may facilitate differential diagnosis of small hepatic metastatic lesions with diverse primary origins, especially the source of colorectal cancer.