TABLE 3.

Comparison of Renal Tumor Area Under the Curve Signals Between 2 Hyperpolarized ¹³C Pyruvate Magnetic Resonance Imaging Acquisitions in the Same Patient on the Same Day^a

Patient	First Injection	Second Injection	Difference, %
Lactate
3 (first bSSFP, second GRE)	1.59	1.30	20.0
4 (first GRE, second bSSFP)	0.96	0.97	1.0
5 (first GRE, second GRE)	1.45	1.38	5.1
6 (first GRE, second bSSFP)	1.24	1.41	12.6
8 (first GRE, second GRE)	0.78	0.75	4.0
Mean			8.6
Pyruvate
3 (both GRE)	0.91	0.83	9.0
4 (both GRE)	1.72	1.72	0.3
5 (both GRE)	1.77	1.77	0.1
6 (both GRE)	1.08	1.11	2.3
8 (both GRE)	0.64	0.62	4.2
Mean			3.2

Abbreviations: bSSFP, balanced steady-state free precession sequence; GRE, gradient echo sequence.

^aTumor signals for each metabolite were normalized to adjacent mean kidney parenchyma signals. ¹³C pyruvate images were acquired using GRE sequences. ¹³C lactate images were acquired using either GRE or metabolite-specific bSSFP sequences.