POSTER PRESENTATION Open Access First-pass contrast-enhanced imaging versus equilibrium-phase T1 mapping for determining the distribution volume of gadolinium Michael Salerno * , Patrick Antkowiak, John J Green, Rajesh Janardhanan, Ronny A Jiji, Christopher M Kramer, Frederick H Epstein From 2011 SCMR/Euro CMR Joint Scientific Sessions Nice, France. 3-6 February 2011 Introduction Late gadolinium enhancement can identify focal fibrosis, but cannot evaluate diffuse myocardial fibrosis. Multiple methods have been used to determine the partition coefficient (l) and volume of distribution (Vd) of gadolinium to quantify diffuse myocardial fibrosis, including first-pass and T1 mapping based techniques. These two techniques have not been directly compared in the same subjects. Purpose To directly compare the myocardial Vd in normal subjects as determined from first-pass contrast-enhanced imaging with modified Kety analysis versus T1 mapping at contrast equilibrium following continuous infusion of Gd. Methods First-pass contrast-enhanced imaging and T1 mapping measurements were performed in 5 healthy volunteers (age 36±11) on a Siemens 1.5T Avanto. Hematocrit was measured to accurately determine Vd from l. First pass measurements were performed during a bolus injection of 0.1mmol/kg Gd-DTPA with a dual-contrast satura- tion recovery GRE-EPI pulse sequence. Sequence parameters included: TE/TR/ETL/FA1.1ms/6.1ms/4/25°, 270x340mm FOV, resolution 2.7x2.7mm, thickness 10mm. First-pass data was analyzed using a modified Kety model which enabled determination of Vd as well as Ktrans to quantify myocardial perfusion. T1 maps were determined using a MOLLI pulse sequence pre- contrast and during continuous infusion of 0.001 mmol/ kg Gd until equilibrium was achieved. Sequence parameters included: TE/TR/FA 1.1 ms,/2.5ms/35°, FOV= 340 x 260, resolution 1.8mm x 1.8mm, thickness 8mm. The l was determined as the slope of the linear fit of the data on a plot of 1/T1 myocardium versus 1/ T1 blood. The Vd was calculated as l*(1-Hct). Proces- sing of all data was performed with in-house MATLAB programs. Results The mean Ktrans determined from first-pass data was 0.41±0.02. The mean Vd values, while similar, were higher from the first pass technique. (0.34±0.05 for first- pass versus 0.29±0.01 for T1 mapping p=0.02). Conclusions First-pass contrast-enhanced and T1 mapping techniques provide similar measures of Vd of gadolinium in normal subjects, yet each has specific advantages. First- pass imaging is rapid, but spatial resolution and SNR are limited. Equilibrium T1 mapping with continuous infusion is less time-efficient, but spatial resolution and SNR are improved. Published: 2 February 2011 doi:10.1186/1532-429X-13-S1-P17 Cite this article as: Salerno et al.: First-pass contrast-enhanced imaging versus equilibrium-phase T1 mapping for determining the distribution volume of gadolinium. Journal of Cardiovascular Magnetic Resonance 2011 13(Suppl 1):P17. University of Virginia, Charlottesville, VA, USA Salerno et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):P17 http://jcmr-online.com/content/13/S1/P17 © 2011 Salerno et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

First-pass contrast-enhanced imaging versus equilibrium-phase T1 mapping for determining the distribution volume of gadolinium

Download PDF Report

Upload
michael-salerno
View
212
Download
0

Embed Size (px)

Citation preview

Page 1: First-pass contrast-enhanced imaging versus equilibrium-phase T1 mapping for determining the distribution volume of gadolinium

POSTER PRESENTATION Open Access

First-pass contrast-enhanced imaging versusequilibrium-phase T1 mapping for determiningthe distribution volume of gadoliniumMichael Salerno*, Patrick Antkowiak, John J Green, Rajesh Janardhanan, Ronny A Jiji, Christopher M Kramer,Frederick H Epstein

From 2011 SCMR/Euro CMR Joint Scientific SessionsNice, France. 3-6 February 2011

IntroductionLate gadolinium enhancement can identify focal fibrosis,but cannot evaluate diffuse myocardial fibrosis. Multiplemethods have been used to determine the partitioncoefficient (l) and volume of distribution (Vd) of gadoli-nium to quantify diffuse myocardial fibrosis, includingfirst-pass and T1 mapping based techniques. These twotechniques have not been directly compared in the samesubjects.

PurposeTo directly compare the myocardial Vd in normal subjectsas determined from first-pass contrast-enhanced imagingwith modified Kety analysis versus T1 mapping at contrastequilibrium following continuous infusion of Gd.

MethodsFirst-pass contrast-enhanced imaging and T1 mappingmeasurements were performed in 5 healthy volunteers(age 36±11) on a Siemens 1.5T Avanto. Hematocrit wasmeasured to accurately determine Vd from l. First passmeasurements were performed during a bolus injectionof 0.1mmol/kg Gd-DTPA with a dual-contrast satura-tion recovery GRE-EPI pulse sequence. Sequence para-meters included: TE/TR/ETL/FA1.1ms/6.1ms/4/25°,270x340mm FOV, resolution 2.7x2.7mm, thickness10mm. First-pass data was analyzed using a modifiedKety model which enabled determination of Vd as wellas Ktrans to quantify myocardial perfusion. T1 mapswere determined using a MOLLI pulse sequence pre-contrast and during continuous infusion of 0.001 mmol/kg Gd until equilibrium was achieved. Sequence

parameters included: TE/TR/FA 1.1 ms,/2.5ms/35°,FOV= 340 x 260, resolution 1.8mm x 1.8mm, thickness8mm. The l was determined as the slope of the linearfit of the data on a plot of 1/T1 myocardium versus 1/T1 blood. The Vd was calculated as l*(1-Hct). Proces-sing of all data was performed with in-house MATLABprograms.

ResultsThe mean Ktrans determined from first-pass data was0.41±0.02. The mean Vd values, while similar, werehigher from the first pass technique. (0.34±0.05 for first-pass versus 0.29±0.01 for T1 mapping p=0.02).

ConclusionsFirst-pass contrast-enhanced and T1 mapping techni-ques provide similar measures of Vd of gadolinium innormal subjects, yet each has specific advantages. First-pass imaging is rapid, but spatial resolution and SNRare limited. Equilibrium T1 mapping with continuousinfusion is less time-efficient, but spatial resolution andSNR are improved.

Published: 2 February 2011

doi:10.1186/1532-429X-13-S1-P17Cite this article as: Salerno et al.: First-pass contrast-enhanced imagingversus equilibrium-phase T1 mapping for determining the distributionvolume of gadolinium. Journal of Cardiovascular Magnetic Resonance 201113(Suppl 1):P17.

University of Virginia, Charlottesville, VA, USA

Salerno et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):P17http://jcmr-online.com/content/13/S1/P17

© 2011 Salerno et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative CommonsAttribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction inany medium, provided the original work is properly cited.

http://creativecommons.org/licenses/by/2.0