. Author manuscript; available in PMC: 2020 Jan 1.

Published in final edited form as: J Magn Reson Imaging. 2018 Aug 24;49(1):291–303. doi: 10.1002/jmri.26203

Table 3.

Repeatability analysis for mean placental R₂* measured in normal subjects using free-breathing radial MRI at 3 T. The within-technique mean difference (MD_within), absolute within-technique mean difference (MD_abs), within-technique standard deviation (SD_within), and coefficient of repeatability (CR) for placental R₂* measured by two back-to-back scans were calculated for all normal subjects (N=30) and again for the subjects separated into anterior (N = 15) versus posterior (N = 15) placenta implantation positions. The analysis was performed for each gestational age (GA) range.

	GA (Weeks)	MD_within (s⁻¹)	MD_abs (s⁻¹)	SD_within (s⁻¹)	CR (s⁻¹)
All Subjects (N = 30)	14-18	0.32	0.84	1.05	2.92
All Subjects (N = 30)	19-23	0.98	1.73	2.97	8.24¹
Anterior (N = 15)	14-18	0.48	1.05	1.21	3.37
Anterior (N = 15)	19-23	0.24	1.23	1.66	4.60
Posterior (N = 15)	14-18	0.15	0.63	0.87	2.42
Posterior (N = 15)	19-23	1.73	2.23	3.79	10.50¹

Includes two severe outliers during the second scan (see Discussion). By removing these outliers, the CR for 19-23 weeks was 4.20 s⁻¹ (all subjects) and 3.85 s⁻¹ (posterior placenta).