Manganese-Enhanced Magnetic Resonance Imaging for Detection and Characterization of Colorectal Cancers.

Liang Wen,Dan Han,Liping He,Xinan Shi

doi:10.18383/j.tom.2018.00008

Abstract

Here, we investigated the diagnostic performance of manganese (Mn)-enhanced magnetic resonance imaging (MEMRI) in colorectal cancer (CRC). The ability of CRC cell lines SW620 and SW480 to uptake Mn was evaluated and compared with a normal colon cell using MEMRI. Subcutaneous xenografts in nude mice underwent MRI examination at tumor sizes of 5, 10, and 15 mm. Contrast enhancement was compared between gadolinium (Gd)- and Mn-enhanced MRI. SW620 and SW480 cell lines took up more Mn2+ than normal cells, resulting in 4.5 and 2 times greater T1 value shortening than normal cell using in vitro MEMRI (P < .001). Most xenografts (17/23) enhanced markedly on MEMRI. A heterogeneous enhancement pattern invariably noted whether Mn or Gd agents were administered, but tumors imaged using MEMRI showed a greater degree of enhancement with a larger extent of enhanced area than those imaged using Gd-enhanced MRI. The numbers of markedly Mn-enhanced cases were more in the 5-mm-size tumor group than in 10- or 15-mm-size tumor groups. Overall, MEMRI could enhance CRCs and it showed potential in detecting early small lesions and markedly enhancing tumors that had minimal Gd enhancement.

Highlights

Colorectal cancer (CRC) is the third most common form of cancer and the fourth most common cause of death globally
The T1 map analysis indicated that the average T1 value shortening of both SW620 and SW480 tumors in the 5-mm-size tumor group was Ͼ500 milliseconds on the Mn-enhanced scan, it was Ͻ300 milliseconds on the Gd-enhanced scan
In vivo and in vitro studies regarding MEMRI were reported in choroidal melanoma, head and neck tumor, mesothelioma, breast cancer, and medulloblastoma [5, 12,13,14,15,16,17]

Summary

Introduction

Colorectal cancer (CRC) is the third most common form of cancer and the fourth most common cause of death globally. The contrast medium used in conventional MRI, such as Gd-DTPA, is an extracellular nonspecific contrast agent, and lesion detection depends on tumor vascularity. Those with hypovascularity, the diagnostic accuracy of conventional MRI needs to be improved. Manganese (Mn)-enhanced MRI (MEMRI) using an Mn2ϩ agent confers its enhancement effect largely to Mn uptake by cells rather than lesion vascularity. To provide more accurate clinical staging and prognosis, MEMRI could be an important approach to improve early primary CRC detection. This study used MnCl2 as the contrast agent to perform MRI on CRC cell lines and subcutaneous xenograft tumors in nude mice to investigate the diagnostic efficacy of MEMRI to detect early-stage CRC

Methods

Results

Conclusion