Yoko Hieda MD, PhD, Presenter: Nothing to Disclose

Masakatsu Tsurusaki MD, PhD, Abstract Co-Author: Nothing to Disclose

Takashi Katsube, Abstract Co-Author: Nothing to Disclose

Keitaro Sofue, Abstract Co-Author: Nothing to Disclose

Hajime Kitagaki MD, Abstract Co-Author: Nothing to Disclose

Yasuaki Arai MD, Abstract Co-Author: Nothing to Disclose

Kazuro Sugimura MD, PhD, Abstract Co-Author: Research grant, Toshiba Corporation Research grant, Koninklijke Philips Electronics NV Research grant, Mitsubishi Corporation Research grant, Bayer AG Research grant, Eisai Co, Ltd Research grant, DAIICHI SANKYO Group Research Consultant, Shionogi & Co, Ltd

The purpose of this study was to retrospectively evaluate diagnostic efficacy of gadoxetic acid-enhanced magnetic resonance (MR) imaging compared with contrast-enhanced CT in the detection of hepatic metastasis in patients with colorectal carcinoma.

Consecutive 107 patients with histopathologically confirmed colorectal carcinoma underwent gadoxetic acid-enhanced MR imaging and contrast-enhanced CT. Forty-seven with 85 histopathological confirmed hepatic metastases by surgery. All MR studies were performed at a 3 T scanner (Magnetom Trio, Siemens Medical Systems, Erlangen, Germany) and CT were performed at 64-detector rows helical CT scanner (Aquilion Multi, Toshiba Medical, Tokyo, Japan). MR examination consisted of T1-weighted 3 dimensional-gradient echo (3D-GRE) dynamic sequences after bolus-injection of 0.025 mmol gadoxetic acid (Primovist; Bayer Schering Pharma, Osaka, Japan) and hepatocyte-phase after 20 minutes. Diagnostic analysis was performed by sensitivity and positive predictive value (PPV) for the detection of hepatic metastases in combined arterial- and hepatocyte- phase images compared with contrast-enhanced CT by 2 blinded readers. Sensitivity and PPV for the detection of hepatic metastases were compared using McNemar test. Diagnostic accuracy and sensitivity were evaluated using the alternative-free response receiver operator characteristic (AFROC) method.

The overall sensitivity of gadoxetic acid-enhanced MR imagings (89.8%) were significantly higher than that of contrast-enhanced CT (77.8%, p<0.001), especially in the sensitivity of gadoxetic acid- enhanced MR imagings was observed in higher sensitivity in smaller size of lesions (74.2% vs 58.2% in the lesions ≤1cm, 96.8% vs 86.9% in the lesions 1 cm< ≤2cm, 98.2% vs 94.7% in the lesions >2cm). The gadoxetic acid-MR imagings showed significantly higher increased area under the ROC curve (Az value = 0.975) compared with contrast-enhanced CT (Az value = 0.901, p<0.01).

The results of this study demonstrated gadoxetic acid-enhanced MR imagings provided higher detectability for hepatic metastases, especially in smaller size of lesion, compared with contrast-enhanced CT in patients with colorectal carcinoma.

Gadoxetic acid-enhanced MR imaging can detect smaller size of hepatic metastases compared with CT and would provide more feasible surgical or therapeutic direction for patients with colorectal cancer

Hieda, Y, Tsurusaki, M, Katsube, T, Sofue, K, Kitagaki, H, Arai, Y, Sugimura, K, Diagnostic Efficacy of Gadoxetic Acid-enhanced MR Imaging in the Detection of Hepatic Metastasis from Colorectal Carcinoma: Comparison with Contrast-enhanced CT.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11004291.html