Diagnosis of colorectal hepatic metastases: comparison of contrast-enhanced CT, contrast-enhanced US, superparamagnetic iron oxide-enhanced MRI, and gadoxetic acid-enhanced MRI.

PURPOSE: To compare the diagnostic accuracy of contrast-enhanced computed tomography (CE-CT), contrast-enhanced ultrasonography (CE-US), superparamagnetic iron oxide-enhanced magnetic resonance imaging (SPIO-MRI), and gadoxetic acid-enhanced MRI (Gd-EOB-MRI) in the evaluation of colorectal hepatic metastases. MATERIALS AND METHODS: In all, 111 patients with colorectal cancers were enrolled in this study. Of the 112 metastases identified in 46 patients, 31 in 18 patients were confirmed histologically and the remaining 81 in 28 patients were confirmed by follow-up imaging. CE-CT, CE-US, SPIO-MRI, and Gd-EOB-MRI were evaluated. Mean (of three readers, except for CE-US) area under the receiver operating characteristic curve (A(z) ), sensitivities, and positive predictive values (PPV) were calculated. Each value was compared to the others by variance z-test or chi-square test with Bonferroni correction. RESULTS: For all lesions, mean A(z) and sensitivity of Gd-EOB-MRI (0.992, 95% [56/59]) were significantly greater than those of CE-CT (0.847, 63% [71/112]) and CE-US (0.844, 73% [77/106]). For lesions ≤1 cm, mean A(z) and sensitivity of Gd-EOB-MRI (0.999, 92% [22/24]) were significantly greater than those of CE-CT (0.685, 26% [13/50]) and CE-US (0.7, 41% [18/44]). Mean A(z) (95% CI) of SPIO-MRI for all lesions (0.966 [0.929-0.987]) and lesions ≤ 1 cm (0.961 [0.911-0.988]) were significantly greater than those of CE-CT and CE-US. Mean sensitivity of SPIO-MRI for lesions ≤1 cm (63%, 26/41) was significantly greater than that of CE-CT. CONCLUSION: Gd-EOB-MRI and SPIO-MRI were more accurate than CE-CT and CE-US for evaluation of liver metastasis in patients with colorectal carcinoma.

Diagnosis of colorectal hepatic metastases: Contrast-enhanced ultrasonography versus contrast-enhanced computed tomography versus superparamagnetic iron oxide-enhanced magnetic resonance imaging with diffusion-weighted imaging.

PURPOSE: To compare the diagnostic accuracy of contrast-enhanced ultrasonography (CE-US), contrast-enhanced CT (CE-CT), and superparamagnetic iron oxide-enhanced MRI (SPIO-MRI) with diffusion-weighted imaging (DWI) in the evaluation of colorectal hepatic metastases. MATERIALS AND METHODS: Thirty-six patients with colorectal cancers were prospectively enrolled and retrospectively evaluated. Of the 86 metastases identified, 16 were confirmed histologically and the remaining 70 were confirmed by follow-up imaging. CE-CT and SPIO-MRI + DWI were independently evaluated by two readers, whereas CE-US was evaluated by consensus reading of two different readers. Area under receiver operating characteristic curve (A(z)), sensitivities, and positive predictive values (PPVs) were calculated and compared. RESULTS: For both readers, SPIO-MRI+DWI had significantly greater A(z) (0.879 and 0.904) and sensitivity (78% and 87%) for all lesions compared with CE-CT (0.779 and 0.793; 59% and 59%) and CE-US (0.811; 69%), and significantly greater A(z) (0.783 and 0.837) and sensitivity (56% and 73%) for lesions ≤1 cm compared with CE-CT (0.562 and 0.601; 20% and 22%) and CE-US (0.66; 37%). For lesions >1 cm, there was no significant difference in A(z), sensitivity and PPV between all the image sets. CONCLUSION: SPIO-MRI with DWI was the most reliable modality for evaluation of liver metastases particularly for lesions ≤1 cm.