Abstract: Objective  To explore the value of cone beam CT in transarterial chemoembolization of colorectal liver metastases（CRLM), and to provide effective information for the interventional treatment of clinical CRLM. 
Methods  Fifty patients with CRLM were enrolled. A total of 146 metastases were detected by abdominal CT or magnetic resonance imaging (MRI) intensive examination. All patients underwent digital subtraction angiography（DSA） two-dimensional angiography, and the liver metastases（LM） staining, number and location were observed. Cone beam CT(CBCT) enhanced scanning was performed to observe the LM staining, number and location. Combined with the performance of two methods, super-selective lipiodol embolization was performed. After the embolization was completed, the CBCT was scanned again to observe the degree of LM embolization. 
Results  Fifty patients underwent routine DSA. angiography, 97 CRLM were seen. The angiographic findings showed ring-shaped staining around the early tumor in the artery. There was no staining in the central region, and the annular staining in the late arterial phase became lighter. The normal liver parenchyma filling defect was clearly developed. Twenty-four were moderate of blood supply, 73 were lack of blood supply, and no CRLM were rich of blood supply. A total of 142 LM were detected by CBCT enhanced scan, and 45 more than DSA angiography(P＜0.05), there were statistically significant. LM showed peripheral enhancement of the tumor in the CBCT enhanced scan, while the central area was not enhanced, consistent with CT or MRI imaging findings. Fifty patients underwent CBCT scan after embolization, and 142 metastases clearly showed embolization of liver metastases. The 107 metastases were consistent with CBCT enhanced scan and preoperative imaging enhancement, 35 metastases and dual-phase scans. The enhancement range was poor, and the second embolization was performed. The CBCT scan again showed that the deposition range of the liver metastasis was consistent with the enhancement range. 
Conclusion  When patients of CRLM is treated with TACE, CBCT enhanced scan after DSA two-dimensional angiography can effectively detect metastasis missed in two-dimensional angiography, and CBCT plain scan after CRLM embolism can accurately and immediately judge the deposition of iodized oil and improve the TACE efficacy of CRLM. CBCT technique can play a guiding role in CRLM.

Key words: colorectal neoplasms, embolism, tomography, X-ray computed