Edouard Semaan, Presenter: Nothing to Disclose

Bruce Spottiswoode, Abstract Co-Author: Employee, Siemens AG

Benjamin Freed, Abstract Co-Author: Nothing to Disclose

Zoran Stankovic MD, Abstract Co-Author: Nothing to Disclose

Maria Carr, Abstract Co-Author: Nothing to Disclose

Bradley D. Allen MD, Abstract Co-Author: Nothing to Disclose

Sanjiv Shah MD, Abstract Co-Author: Nothing to Disclose

James Christopher Carr MD, Abstract Co-Author: Research Grant, Astellas Group Research support, Siemens AG Speaker, Siemens AG Advisory Board, Guerbet SA

Michael Markl PhD, Abstract Co-Author: Nothing to Disclose

Jeremy Douglas Collins MD, Abstract Co-Author: Consultant, B. Braun Melsungen AG

The purpose of this study is to evaluate an optimized high-resolution MOLLI (HR-MOLLI) technique at 3T and 1.5T for RV ECV calculation in healthy volunteers.

25 healthy volunteers (16 men, 41±14.3yrs) were scanned at 3T(MAGNETOM Skyra, Siemens AG, Healthcare Sector, Erlangen, Germany) and 19 (12 men, 46.8±12.9yrs) were scanned at 1.5T (MAGNETOM, Aera). T1 mapping was performed in the axial orientation using a HR-MOLLI technique, with an in line motion correction algorithm with T1 and T1* parametric map generation using 0.5x0.5x8mm3 voxel. The MOLLI sequence was comprised of two inversion pulses sampling T1 recovery using a 5(3)3 scheme with single shot steady state diastolic readouts. Images were acquiered before and 12-25 minutes after 0.2mmol/kg gadobenate dimeglumine(Multihance, Bracco Diagnostics, Monroe, NJ) infusion as a bolus. Two reviewers quantified basal and mid RV, interventricular septal, and lateral LV wall T1 values from T1 parametric maps. RV and LV ECV ranges were calculated as oriinally described by Jerosch-Harold et al assuming normal hematocrit values (women:0.38-0.46, men: 0.42-0.54). Global ECV values were compared using the students´s t-test. Intra and inter-observer variance was measured by the intraclass correlation coefficient (ICC).

One 3T volunteer and four 1.5T subjects were excluded due to motion blurring of the RV free wall. Table 1 shows RV and LV global ECV ranges by field strength and BP T1 estimation method. Global RV and LV ECV ranges were significantly different at 3T and 1.5T(p<0.001). Intraobserver variance for global RV and LV ECV was 0.78 and 0.92 for 3T and 0.83 and 0.79 for 1.5T respectively. Interobserver variance for global RV and LV ECV was 0.75 and 0.71 at 3T and 0.58 and 0.71 at 1.5T respectively.

This feasibility study demonstrates that HR-MOLLI can quantitate the global RV ECV fraction at both 1.5T and 3T with good intra and interobserver variance, also that blood pool T1 estimates without a look-locker correction have a significant influence on the RV and LV ECV. We also found a field strength influence on RV and LV ECV values, highlighting the need to determine field strength specific values.

Determination of the ECV by T1 estimation using MOLLI techniques enables quantitation of diffuse myocardial fibrosis and it may be feasible to measure in the RV.

Semaan, E, Spottiswoode, B, Freed, B, Stankovic, Z, Carr, M, Allen, B, Shah, S, Carr, J, Markl, M, Collins, J, Feasibility of High-resolution Modified Look-locker Inversion Recovery (HR-MOLLI) for Right Ventricular T1 Mapping at 3T and 1.5T in Healthy Volunteers.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14018407.html