Evaluation of lymph node metastases: comparison of gadofluorine M-enhanced MRI and diffusion-weighted MRI in a rabbit VX2 rectal cancer model.

Abstract

PURPOSE:

To compare the diagnostic performance of a diffusion-weighted imaging (DWI) dataset and a gadofluorine M-enhanced imaging dataset for identifying lymph node (LN) metastases in a rabbit rectal cancer model.

MATERIALS AND METHODS:

VX2 carcinomas were injected into the rectum of 26 rabbits. Four weeks later, T2-weighted imaging (T2WI), pre-T1WI, DWI, and post-T1WI were performed. Two radiologists independently reviewed the DWI set (T2WI, pre-T1WI, DWI) and the gadofluorine M set (T2WI, pre- and post-T1WI) and recorded their confidence scores for LN metastasis on a per-LN basis. Receiver operating characteristic (ROC) analysis was performed to compare the area under the ROC curve (A(z) ) of the two imaging sets. Histopathologic results were used as the reference standard.

RESULTS:

The A(z) and sensitivity of the gadofluorine M set were comparable to those of the DWI set (A(z) , for reader 1, 0.849, 0.829, P = 0.571; for reader 2, 0.923, 0.876, P = 0.212; sensitivity, for reader 1, 97%, 97%; for reader 2, 97%, 92%, P = 0.304). The specificity of the former was greater than that of the latter (for reader 1, 65%, 53%, P = 0.0003; for reader 2, 81%, 68%, P = 0.01).

CONCLUSION:

Gadofluorine M-enhanced images provided greater specificity than DWI for identifying LN metastases, whereas the A(z) and sensitivity of the former were comparable to those of the latter.

• Authors: Seung Ho Kim, Jeong Min Lee, Sung Kyoung Moon, Yong Eun Chung, Jin Ho Paik, Seung Hong Choi, Min Uk Kim, Joon Koo Han, Byung Ihn Choi
• Journal: Journal of magnetic resonance imaging : JMRI (J Magn Reson Imaging) Vol. 35 Issue 5 Pg. 1179-86 (May 2012) ISSN: 1522-2586 [Electronic] United States
• PMID: 22247081 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 Wiley Periodicals, Inc.

Chemical References

• Contrast Media
• Fluorocarbons
• Organometallic Compounds
• gadofluorine M

Topics

• Animals
• Cell Line, Tumor
• Contrast Media
• Diffusion Magnetic Resonance Imaging
• Disease Models, Animal
• Fluorocarbons
• Image Enhancement (methods)
• Lymphatic Metastasis (diagnosis)
• Magnetic Resonance Imaging (methods)
• Neoplasm Transplantation
• Neoplasms, Experimental
• Organometallic Compounds
• ROC Curve
• Rabbits
• Rectal Neoplasms (pathology)
• Sensitivity and Specificity