Developing a medical device-grade T2 phantom optimized for myocardial T2 mapping by cardiovascular magnetic resonance

Table 1 Measured T₁|T₂ myocardial values for the 9 tubes and outer matrix fill

	T1 (ms)			T2 (ms)			Agarose (%)	Ni²⁺ (mM)
	1.4 T	1.5 T	3 T	1.4 T	1.5 T	3 T	Agarose (%)	Ni²⁺ (mM)
Short T₂ native myo at both 1.5 T and 3 T (A)	821	803	807	40	35	34	1.261	3.139
Medium T₂ native myo at 1.5 T (B)	978	982	988	50	43	41	0.969	2.511
Medium T₂ native myo at 3 T (C)	1122	1073	1137	48	42	40	0.773	2.639
Long T₂ native myo at 1.5 T (D)	1083	1090	1130	71	60	59	0.821	1.775
Long T₂ native myo at 3 T (E)	1237	1225	1228	70	61	59	0.649	1.791
Long-normal T₂ native myo at 1.5 T (F)	1030	1015	1019	60	52	50	0.882	2.081
Very long T₂ native myo at 3 T (G)	1295	1287	1302	82	70	68	0.594	1.562
Mildly long T₁ & T₂ native myo at 1.5 & 3 T (H)	1221	1182	1217	60	52	51	0.664	2.139
Medium T₁ & T₂ post-GBCA* myo at 1.5 & 3 T (I)	440	435	445	47	41	40	2.840	2.502
Outer gel matrix fill	850	-	-	140	-	-	1.155	0.780

All the T₁|T₂ presented in this table were measured in our final phantom (n = 1). T₁|T₂ at 1.4 T were measured by a Bruker minispec mq60 relaxometer (22 °C) at Resonance Health laboratory in Australia; T₁ and T₂ at 1.5 T and 3 T were measured by inversion recovery gradient echo and single-echo spin echo at University College London at baseline. The definitions of ‘short’, ‘medium’, ‘long-normal’, ‘long’, ‘mildly long’ and ‘very long’ are subjective and relative to the average normal native myocardial T₂ in health
^*The post-contrast myocardial T₁ behavior being modelled here is based on the published literature around the use of Dotarem (Gadoterate meglumine, Guerbet, France) so the effects may not be generalizable to other GBCAs
GBCA gadolinium-based contrast agent; myo myocardium; ms, milliseconds

ISSN: 1532-429X