Abbreviated Gadoxetic Acid-enhanced MRI with Second-Shot Arterial Phase Imaging for Liver Metastasis Evaluation

Abstract

Purpose: To evaluate the feasibility of an abbreviated gadoxetic acid-enhanced MRI protocol including second-shot arterial phase (SSAP) imaging for liver metastasis evaluation.

Materials and methods: For this retrospective study, a total of 197 patients with cancer (117 men and 80 women; mean age, 62.9 years) were included who underwent gadoxetic acid-enhanced MRI performed by using a modified injection protocol for liver metastasis evaluation from July to August 2017. The modified injection protocol included routine dynamic imaging after a first injection of 6 mL and SSAP imaging after a second injection of 4 mL. Image set 1 was obtained with the full original protocol. Image set 2 consisted of T2-weighted, diffusion-weighted, hepatobiliary phase, and SSAP images (the simulated abbreviated protocol). Acquisition time was measured in each image set. The diagnostic performance of each image set was compared by using a jackknife alternative free-response receiver operating characteristic analysis. Image quality evaluation and visual assessment of vascularity were performed on the original arterial phase images, the SSAP images, and their subtraction images.

Results: The acquisition time was significantly shorter in image set 2 than in image set 1 (18.6 vs 6.2 minutes, P <.0001). The reader-averaged figure-of-merit was not significantly different between image sets 1 and 2 (P = .197). The mean motion artifact score was significantly lower for the SSAP images than for the original arterial phase images (P <.001). All hypervascular metastases (n = 72) showed hyperintensity on the SSAP and/or the second subtraction images.

Conclusion: An abbreviated MRI protocol including SSAP is feasible for liver metastasis evaluation, providing faster image acquisition while preserving diagnostic performance, image quality, and visual vascularity.Keywords: Abdomen/GI, Comparative Studies, Liver, MR-Imaging, Metastases© RSNA, 2019Supplemental material is available for this article.

Conflict of interest statement

Disclosures of Conflicts of Interest: J.W.K. disclosed no relevant relationships. C.H.L. disclosed no relevant relationships. Y.S.P. disclosed no relevant relationships. J.L. disclosed no relevant relationships. K.A.K. disclosed no relevant relationships.

2019 by the Radiological Society of North America, Inc.

Figures

Figure 1:

Flowchart of the study population.

Figure 2:

Schematic diagrams of the original MRI protocol, the modified MRI protocol including second-shot arterial phase imaging, and the simulated abbreviated MRI protocol. DWI = diffusion-weighted imaging, HASTE = half-Fourier acquisition single-shot turbo spin echo.

Figure 3a:

Axial images from MRI in a 60-year-old man with a liver metastasis from colon cancer. A new small hepatic metastasis (arrow) occurred during postoperative follow-up. The small metastatic lesion showed hyperintensity on the T2-weighted image and diffusion-weighted image and hypointensity on the hepatobiliary phase image (not shown). On (a) the precontrast T1-weighted image, the lesion (arrow) shows hypointensity. However, it is difficult to detect the lesion on (b) the original arterial phase image because of motion artifact (score 4). On (c) the second precontrast T1-weighted image, the lesion (arrow) shows hypointensity. Motion artifact is decreased on (d) the second-shot arterial phase image, facilitating detection of the lesion (arrow).

Figure 3b:

Axial images from MRI in a 60-year-old man with a liver metastasis from colon cancer. A new small hepatic metastasis (arrow) occurred during postoperative follow-up. The small metastatic lesion showed hyperintensity on the T2-weighted image and diffusion-weighted image and hypointensity on the hepatobiliary phase image (not shown). On (a) the precontrast T1-weighted image, the lesion (arrow) shows hypointensity. However, it is difficult to detect the lesion on (b) the original arterial phase image because of motion artifact (score 4). On (c) the second precontrast T1-weighted image, the lesion (arrow) shows hypointensity. Motion artifact is decreased on (d) the second-shot arterial phase image, facilitating detection of the lesion (arrow).

Figure 3c:

Axial images from MRI in a 60-year-old man with a liver metastasis from colon cancer. A new small hepatic metastasis (arrow) occurred during postoperative follow-up. The small metastatic lesion showed hyperintensity on the T2-weighted image and diffusion-weighted image and hypointensity on the hepatobiliary phase image (not shown). On (a) the precontrast T1-weighted image, the lesion (arrow) shows hypointensity. However, it is difficult to detect the lesion on (b) the original arterial phase image because of motion artifact (score 4). On (c) the second precontrast T1-weighted image, the lesion (arrow) shows hypointensity. Motion artifact is decreased on (d) the second-shot arterial phase image, facilitating detection of the lesion (arrow).

Figure 3d:

Axial images from MRI in a 60-year-old man with a liver metastasis from colon cancer. A new small hepatic metastasis (arrow) occurred during postoperative follow-up. The small metastatic lesion showed hyperintensity on the T2-weighted image and diffusion-weighted image and hypointensity on the hepatobiliary phase image (not shown). On (a) the precontrast T1-weighted image, the lesion (arrow) shows hypointensity. However, it is difficult to detect the lesion on (b) the original arterial phase image because of motion artifact (score 4). On (c) the second precontrast T1-weighted image, the lesion (arrow) shows hypointensity. Motion artifact is decreased on (d) the second-shot arterial phase image, facilitating detection of the lesion (arrow).

Figure 4a:

Axial images from MRI in a 75-year-old man with a hypervascular liver metastasis from renal cell carcinoma. On the precontrast T1-weighted image (not shown), the liver metastasis showed hypointensity. (a) The original arterial phase image and (b) its subtraction image show hypervascular metastasis (arrow) in liver segment VIII. On the second precontrast T1-weighted image (not shown), the tumor showed hypointensity. The tumor (arrow) shows isointensity on (c) the second-shot arterial phase image but hyperintensity on (d) the second subtraction image.

Figure 4b:

Axial images from MRI in a 75-year-old man with a hypervascular liver metastasis from renal cell carcinoma. On the precontrast T1-weighted image (not shown), the liver metastasis showed hypointensity. (a) The original arterial phase image and (b) its subtraction image show hypervascular metastasis (arrow) in liver segment VIII. On the second precontrast T1-weighted image (not shown), the tumor showed hypointensity. The tumor (arrow) shows isointensity on (c) the second-shot arterial phase image but hyperintensity on (d) the second subtraction image.

Figure 4c:

Axial images from MRI in a 75-year-old man with a hypervascular liver metastasis from renal cell carcinoma. On the precontrast T1-weighted image (not shown), the liver metastasis showed hypointensity. (a) The original arterial phase image and (b) its subtraction image show hypervascular metastasis (arrow) in liver segment VIII. On the second precontrast T1-weighted image (not shown), the tumor showed hypointensity. The tumor (arrow) shows isointensity on (c) the second-shot arterial phase image but hyperintensity on (d) the second subtraction image.

Figure 4d:

Axial images from MRI in a 75-year-old man with a hypervascular liver metastasis from renal cell carcinoma. On the precontrast T1-weighted image (not shown), the liver metastasis showed hypointensity. (a) The original arterial phase image and (b) its subtraction image show hypervascular metastasis (arrow) in liver segment VIII. On the second precontrast T1-weighted image (not shown), the tumor showed hypointensity. The tumor (arrow) shows isointensity on (c) the second-shot arterial phase image but hyperintensity on (d) the second subtraction image.