Interobserver and Test-Retest Reproducibility of T1ρ and T2 Measurements of Lumbar Intervertebral Discs by 3T Magnetic Resonance Imaging.
To investigate the interobserver and test-retest reproducibility of T1ρ and T2 measurements of lumbar intervertebral discs using 3T magnetic resonance imaging (MRI).



This study included a total of 51 volunteers (female, 26; male, 25; mean age, 54 ± 16.3 years) who underwent lumbar spine MRI with a 3.0 T scanner. Amongst these subjects, 40 underwent repeat T1ρ and T2 measurement acquisitions with identical image protocol. Two observers independently performed the region of interest measurements in the nuclei pulposi of the discs from L1-2 through L5-S1 levels. Statistical analysis was performed using intraclass correlation coefficient (ICC) with a two-way random model of absolute agreement. Comparison of the ICC values was done after acquisition of ICC values using Z test. Statistical significance was defined aspvalue < 0.05.



The ICCs of interobserver reproducibility were 0.951 and 0.672 for T1ρ and T2 mapping, respectively. The ICCs of test-retest reproducibility (40 subjects) for T1ρ and T2 measurements were 0.922 and 0.617 for observer A and 0.914 and 0.628 for observer B, respectively. In the comparison of the aforementioned ICCs, ICCs of interobserver and test-retest reproducibility for T1ρ mapping were significantly higher than T2 mapping (p< 0.001).



The interobserver and test-retest reproducibility of T1ρ mapping were significantly higher than those of T2 mapping for the quantitative assessment of nuclei pulposi of lumbar intervertebral discs.
Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
Yeon Hwa
YH
Yoo
Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
Choon-Sik
CS
Yoon
Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
Na Lae
NL
Eun
GE Health Care, Seoul 06060, Korea.
Moon-Jung
MJ
Hwang
Biostatistics Collaboration Lab, Yonsei University College of Medicine, Seoul 03722, Korea.
Hanna
H
Yoo
GE Health Care, Milwaukee, WI 53209, USA.
Robert D
RD
Peters
Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
Tae-Sub
TS
Chung
Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea.
Young Han
YH
Lee
Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea.
Jin-Suck
JS
Suh
Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
Sungjun
S
Kim
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging; D055959:Intervertebral Disc Degeneration / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D000070614:Nucleus Pulposus / Q000000981:diagnostic imaging; D011446:Prospective Studies; D015203:Reproducibility of Results; D012720:Severity of Illness Index
Disc degeneration; Intervertebral disc; Magnetic resonance imaging; Reproducibility; T1 rho; T2 mapping