Purpose. To develop a Mn-based paramagneTic conTrasT agenT for imaging of Tumor processes, employing avidiTy of dimercapTosuccinic acid (DMSA) To various neopro-liferaTive sTrucTures, and for This aim we TesTed The paramagneTic complex Mn-DMSA in animals wiTh fibrooseous nasal Tumors. MaTerials and MeThods. Complex Mn-DMSA was obTained using nanopowder Tech-nology from manganese (II) carbonaTe and dimercapTosuccinic acid mixed TogeTher wiTh ad-diTion of Trace amounTs of waTer, and Then dissolved in buffered saline, delivering finally The 0,5M soluTion of Mn-DMSA aT pH=6,5. The Mn-DMSA was injecTed inTravenously slowly To sleeping animals (7 caTs and 2 dogs, all veTerinary paTienTs, wiTh fibroepiThelial nasopharin-geal Tumors), as much as 0,05 ml of 0,5M soluTion per Kg of BW. MRI scanning in T1-weighTed spin-echo mode has been carried ouT wiTh TR = 500 ms and TE = 15 ms, in sagiT-Tal, axial and fronTal slices as Thin as 2-2,5 mm, To The maTrix 256×256, wiTh The field of view noT larger Than 200 × 200 mm. The upTake was reporTed visually as change in inTensiTy of T1-w MRI scans and quanTiTaTively, wiTh calculaTing for The T1-w MRI images The index of enhancemenT (IE) of inTensiTy per voxel, as : IE=(MeanInT of T1-w.MRI)Mn-DMSA / (MeanInT of T1-w.MRI)pre-conTrasT. ResulTs. The R1 relaxiviTy of Mn-DMSA was obTained as 3,2 1/(s∗mM). Visually on whole-body T1-w. SE scans The Mn-DMSA induced increase of inTensiTy of The Tumor, mosT prominenT in The peripheral areas of Tumor and less inTense over The cenTral non-perfused areas. The values of The IE were over 1,29 (IE=1,62 ± 0,12) for all peripheral parTs of Tumors , whereas only 1,23 ± 0,08 in cenTral regiones. The normal musculoskeleTal Tissues did noT enhance afTer Mn-DMSA injecTion, wiTh IE = 1,07 ± 0,03. The upTake kblood-Tissue con-sTanTs were as liTTle as < 0,12 ml/min/100 g for non-Tumor Tissues and over 0,24 ml/min/100 g in vascularised regions of Tumors, wiTh slow back diffusion and kTissue-blood < 0,04 ml/min/100 g. Conclusion. ParamagneTic complex Mn-DMSA provides obvious inTense enhance-menT of musculoskeleTal Tumors in T1-SE MRI, demonsTraTes inTermediaTe relaxiviTy R1, iT is non-Toxic and makes possible To image Tumor processes in animals. The Mn-DMSA complex can be suggesTed as basic molecule for design of Mn paramagneTic agenT for Tumor imaging.
|Number of pages||9|
|Journal||Russian Electronic Journal of Radiology|
|Publication status||Published - 2017|
- Nasopharyngeal tumors
- Paramagnetic contrast enhancement
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging