Nofiele Joris Tchouala, Haedicke Inga E, Zhu Yong Le K, Zhang Xiao-an, Cheng Hai-Ling Margaret
The Research Institute and Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada.
J Magn Reson Imaging. 2015 Feb;41(2):397-403. doi: 10.1002/jmri.24561. Epub 2014 Jan 8.
To evaluate a new formulation of manganese porphyrin as a potential gadolinium (Gd)-free extracellular magnetic resonance imaging (MRI) contrast agent for dynamic contrast-enhanced (DCE) MRI of tumors.
A previously reported new contrast agent, MnTCP, was evaluated in six female tumor-bearing nude rats. MRI was performed on a 3 T clinical scanner 3 to 4 weeks after inoculation of breast tumor cells in the mammary fat pads. Gd-DTPA was injected intravenously, followed by injection of MnTCP at least 2 hours later (both at 0.05 mmol/kg). T1 relaxation time measurements and DCE-MRI were performed.
Enhancement and clearance patterns were visually similar between MnTCP and Gd-DTPA. However, relative R1 increases in all 11 tumors were larger for MnTCP over 60 minutes postcontrast, the difference being significant as late as 20 minutes (R1post /R1pre = 1.42 ± 0.15 for MnTCP vs. 1.20 ± 0.08 for Gd-DTPA, P < 0.05). R1 -related effects for MnTCP were largely reduced after 60 minutes (R1post /R1pre = 1.13 ± 0.07) and completely gone within 24 hours (R1post /R1pre = 0.97 ± 0.06). DCE-MRI revealed a consistently larger (1.5 to over 2-fold) peak enhancement and higher values of the steepest slope, time-to-peak, and AUC60 in all tumors with MnTCP (P < 0.01).
MnTCP is an alternative to extracellular Gd agents for tumor imaging, offering sensitive detection and rapid renal clearance.
评估一种新的锰卟啉制剂作为一种潜在的无钆（Gd）细胞外磁共振成像（MRI）造影剂用于肿瘤动态对比增强（DCE）MRI的效果。
在六只荷瘤雌性裸鼠中评估一种先前报道的新型造影剂MnTCP。在乳腺脂肪垫接种乳腺肿瘤细胞3至4周后，在3T临床扫描仪上进行MRI检查。静脉注射钆喷酸葡胺（Gd-DTPA），至少2小时后注射MnTCP（均为0.05 mmol/kg）。进行T1弛豫时间测量和DCE-MRI检查。
MnTCP和Gd-DTPA的增强和清除模式在视觉上相似。然而，在造影后60分钟内，所有11个肿瘤中MnTCP的相对R1增加幅度均大于Gd-DTPA，差异在20分钟时仍很显著（MnTCP的R1post /R1pre = 1.42 ± 0.15，Gd-DTPA的R1post /R1pre = 1.20 ± 0.08，P < 0.05）。60分钟后，MnTCP的R1相关效应大幅降低（R1post /R1pre = 1.13 ± 0.07），并在24小时内完全消失（R1post /R1pre = 0.97 ± 0.06）。DCE-MRI显示，使用MnTCP时，所有肿瘤的峰值增强始终更大（1.5至超过2倍），并且最陡斜率、达峰时间和AUC60的值更高（P < 0.01）。
MnTCP可作为细胞外Gd剂用于肿瘤成像的替代物，具有灵敏检测和快速经肾清除的特点。
