Conference Paper: Comparison of gadolinium loaded and empty carbon nanotubes as high performance MRI contrast agent

File Download

No File Attached
The HKU Scholars Hub has contact details for these author(s).
- Dr Lam, Edmund Yin Mun

Links for fulltext
(May Require Subscription)

Publisher Website: 10.1007/s11307-009-0251-y
Find via

Supplementary

Citations:
- Scopus:
- Web of Science:
- PubMed Central:
Item Statistics (The Hub)
Appears in Collections:
- Electrical & Electronic Engineering: Conference papers

Title	Comparison of gadolinium loaded and empty carbon nanotubes as high performance MRI contrast agent
Authors	Tang, AMY Wong, K Ananta, JS Lam, EYM Wilson, LJ Wong, S
Keywords	Medical sciences Radiology and nuclear medicine
Issue Date	2009
Publisher	Springer New York LLC.
Citation	The 2009 World Molecular Imaging Congress, Montreal, Canada, 23-26 September 2009. [How to Cite?] DOI: http://dx.doi.org/10.1007/s11307-009-0251-y
Abstract	Introduction: Gadolinium loaded ultra-short single walled carbon nanotubes (US-tubes) has been proposed as an effective high r2 relaxivity contrast agent for use in MR molecular imaging. However, the true active ingredients for inheriting its high performance r2 characteristics, is remain unknown. In this study, we compare the R2 and R2* relaxation rate of the US-tubes with/without Gadolinium ions encapsulation. Methods: Two types of US-tubes MRI phantoms were prepared: (i) Gadonanotubes with 41 μM Gd and (ii) empty US-tubes. Each type of nanotubes was dispersed in pluronic solution with carbon concentration of 275 mg/L and transferred to a 1 cc syringe for MRI imaging. MRI imaging was performed in a 3T MRI scanner using a 35 mm volume coil with 2D spin echo (TR=1500 ms, TE=20–80 ms with 10 ms increment) and 2D gradient echo (alpha=90, TR=1500 ms, TE=20–80 ms with 5 ms increment) sequences to evaluate the R2 and R2* respectively. A 1 mm thick single slice was obtained at each TE cutting in the middle of the 3.5 cm long filled syringe placed parallel to the main magnetic field. T2 and T2* were determined by linear fitting of the measured image intensities at each TE at each phantom into log(S) = log(S0)-TE/T2 and log(S) = log(S0)-TE/T2. Results and Discussions: Table 1 shows the estimated R2 and R2 relaxation rates of the phantoms. R2 represents the coefficient of determinations of the linear fitting. Both Gadonanotubes and empty US-tubes show high R2 and R2* relaxation rates with the R2* being 6–11% stronger than R2. The slight increase in R2* may attribute to bulk magnetic susceptibility effects due to the presence of metal ions inside the US-tubes. Nethertheless,the R2* observed is small when compared with that of other superparamagnetic contrast agents which usually show a few times increase in R2*. This may be due to the low concentration (in μM) and lose density packing of the metal ions inside the tubes. For empty US-tubes, it is observed that its relaxivities are as good as Gadolinium loaded US-tubes. Additional Gd3+ loading does not significantly increase the relaxivities of the US-tubes. Therefore, it is reasonable to consider using empty US-tubes as a high performance MRI contrast agent as well as drug/gene delivery carrier, with the delivery items being encapsulating inside its hollow interior space.
Description	Molecular Imaging and Biology, 2009, v. 12, suppl. 1, p. S41-S42 Abstract no. J080
ISSN	1536-1632 2011 Impact Factor: 3.844 2011 SCImago Journal Rankings: 0.313
DOI	http://dx.doi.org/10.1007/s11307-009-0251-y

DC Field	Value
dc.contributor.author	Tang, AMY
dc.contributor.author	Wong, K
dc.contributor.author	Ananta, JS
dc.contributor.author	Lam, EYM
dc.contributor.author	Wilson, LJ
dc.contributor.author	Wong, S
dc.date.accessioned	2010-10-31T12:15:07Z
dc.date.available	2010-10-31T12:15:07Z
dc.date.issued	2009
dc.description.abstract	Introduction: Gadolinium loaded ultra-short single walled carbon nanotubes (US-tubes) has been proposed as an effective high r2 relaxivity contrast agent for use in MR molecular imaging. However, the true active ingredients for inheriting its high performance r2 characteristics, is remain unknown. In this study, we compare the R2 and R2* relaxation rate of the US-tubes with/without Gadolinium ions encapsulation. Methods: Two types of US-tubes MRI phantoms were prepared: (i) Gadonanotubes with 41 μM Gd and (ii) empty US-tubes. Each type of nanotubes was dispersed in pluronic solution with carbon concentration of 275 mg/L and transferred to a 1 cc syringe for MRI imaging. MRI imaging was performed in a 3T MRI scanner using a 35 mm volume coil with 2D spin echo (TR=1500 ms, TE=20–80 ms with 10 ms increment) and 2D gradient echo (alpha=90, TR=1500 ms, TE=20–80 ms with 5 ms increment) sequences to evaluate the R2 and R2* respectively. A 1 mm thick single slice was obtained at each TE cutting in the middle of the 3.5 cm long filled syringe placed parallel to the main magnetic field. T2 and T2* were determined by linear fitting of the measured image intensities at each TE at each phantom into log(S) = log(S0)-TE/T2 and log(S) = log(S0)-TE/T2. Results and Discussions: Table 1 shows the estimated R2 and R2 relaxation rates of the phantoms. R2 represents the coefficient of determinations of the linear fitting. Both Gadonanotubes and empty US-tubes show high R2 and R2* relaxation rates with the R2* being 6–11% stronger than R2. The slight increase in R2* may attribute to bulk magnetic susceptibility effects due to the presence of metal ions inside the US-tubes. Nethertheless,the R2* observed is small when compared with that of other superparamagnetic contrast agents which usually show a few times increase in R2*. This may be due to the low concentration (in μM) and lose density packing of the metal ions inside the tubes. For empty US-tubes, it is observed that its relaxivities are as good as Gadolinium loaded US-tubes. Additional Gd3+ loading does not significantly increase the relaxivities of the US-tubes. Therefore, it is reasonable to consider using empty US-tubes as a high performance MRI contrast agent as well as drug/gene delivery carrier, with the delivery items being encapsulating inside its hollow interior space.
dc.description	Molecular Imaging and Biology, 2009, v. 12, suppl. 1, p. S41-S42
dc.description	Abstract no. J080
dc.identifier.citation	The 2009 World Molecular Imaging Congress, Montreal, Canada, 23-26 September 2009. [How to Cite?] DOI: http://dx.doi.org/10.1007/s11307-009-0251-y
dc.identifier.doi	http://dx.doi.org/10.1007/s11307-009-0251-y
dc.identifier.epage	S42
dc.identifier.hkuros	171690
dc.identifier.issn	1536-1632 2011 Impact Factor: 3.844 2011 SCImago Journal Rankings: 0.313
dc.identifier.issue	suppl. 1
dc.identifier.openurl
dc.identifier.spage	S41
dc.identifier.uri	http://hdl.handle.net/10722/126198
dc.identifier.volume	12
dc.language	eng
dc.publisher	Springer New York LLC.
dc.relation.ispartof	World Molecular Imaging Congress
dc.rights	The original publication is available at www.springerlink.com
dc.subject	Medical sciences
dc.subject	Radiology and nuclear medicine
dc.title	Comparison of gadolinium loaded and empty carbon nanotubes as high performance MRI contrast agent
dc.type	Conference_Paper

<?xml encoding="utf-8" version="1.0"?><item><contributor.author>Tang, AMY</contributor.author><contributor.author>Wong, K</contributor.author><contributor.author>Ananta, JS</contributor.author><contributor.author>Lam, EYM</contributor.author><contributor.author>Wilson, LJ</contributor.author><contributor.author>Wong, S</contributor.author><date.accessioned>2010-10-31T12:15:07Z</date.accessioned><date.available>2010-10-31T12:15:07Z</date.available><date.issued>2009</date.issued><identifier.citation>The 2009 World Molecular Imaging Congress, Montreal, Canada, 23-26 September 2009.</identifier.citation><identifier.issn>1536-1632</identifier.issn><identifier.uri>http://hdl.handle.net/10722/126198</identifier.uri><description>Molecular Imaging and Biology, 2009, v. 12, suppl. 1, p. S41-S42</description><description>Abstract no. J080</description><description.abstract>Introduction: Gadolinium loaded ultra-short single walled carbon nanotubes (US-tubes) has been proposed as an effective high r2 relaxivity contrast agent for use in MR molecular imaging. However, the true active ingredients for inheriting its high performance r2 characteristics, is remain unknown. In this study, we compare the R2 and R2* relaxation rate of the US-tubes with/without Gadolinium ions encapsulation. Methods: Two types of US-tubes MRI phantoms were prepared: (i) Gadonanotubes with 41 &#956;M Gd and (ii) empty US-tubes. Each type of nanotubes was dispersed in pluronic solution with carbon concentration of 275 mg/L and transferred to a 1 cc syringe for MRI imaging. MRI imaging was performed in a 3T MRI scanner using a 35 mm volume coil with 2D spin echo (TR=1500 ms, TE=20&#8211;80 ms with 10 ms increment) and 2D gradient echo (alpha=90, TR=1500 ms, TE=20&#8211;80 ms with 5 ms increment) sequences to evaluate the R2 and R2* respectively. A 1 mm thick single slice was obtained at each TE cutting in the middle of the 3.5 cm long filled syringe placed parallel to the main magnetic field. T2 and T2* were determined by linear fitting of the measured image intensities at each TE at each phantom into log(S) = log(S0)-TE/T2 and log(S) = log(S0)-TE/T2*. Results and Discussions: Table 1 shows the estimated R2 and R2* relaxation rates of the phantoms. R2 represents the coefficient of determinations of the linear fitting. Both Gadonanotubes and empty US-tubes show high R2 and R2* relaxation rates with the R2* being 6&#8211;11% stronger than R2. The slight increase in R2* may attribute to bulk magnetic susceptibility effects due to the presence of metal ions inside the US-tubes. Nethertheless,the R2* observed is small when compared with that of other superparamagnetic contrast agents which usually show a few times increase in R2*. This may be due to the low concentration (in &#956;M) and lose density packing of the metal ions inside the tubes. For empty US-tubes, it is observed that its relaxivities are as good as Gadolinium loaded US-tubes. Additional Gd3+ loading does not significantly increase the relaxivities of the US-tubes. Therefore, it is reasonable to consider using empty US-tubes as a high performance MRI contrast agent as well as drug/gene delivery carrier, with the delivery items being encapsulating inside its hollow interior space.</description.abstract><language>eng</language><publisher>Springer New York LLC.</publisher><relation.ispartof>World Molecular Imaging Congress</relation.ispartof><rights>The original publication is available at www.springerlink.com</rights><subject>Medical sciences</subject><subject>Radiology and nuclear medicine</subject><title>Comparison of gadolinium loaded and empty carbon nanotubes as high performance MRI contrast agent</title><type>Conference_Paper</type><identifier.openurl>http://library.hku.hk:4550/resserv?sid=HKU:IR&amp;issn=1536-1632&amp;volume=12, suppl. 1&amp;spage=S41&amp;epage=S42&amp;date=2009&amp;atitle=Comparison+of+gadolinium+loaded+and+empty+carbon+nanotubes+as+high+performance+MRI+contrast+agent</identifier.openurl><identifier.doi>10.1007/s11307-009-0251-y</identifier.doi><identifier.hkuros>171690</identifier.hkuros><identifier.volume>12</identifier.volume><identifier.issue>suppl. 1</identifier.issue><identifier.spage>S41</identifier.spage><identifier.epage>S42</identifier.epage></item>

Conference Paper: Comparison of gadolinium loaded and empty carbon nanotubes as high performance MRI contrast agent

The HKU Scholars Hub has contact details for these author(s).