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The usefulness of isotropic single-slab 3D Turbo Spin Echo images compared with fast spin echo T2-weighted images in lumbar spine. 2008

General Spine

Myung Jin Shin, MD,
HJ Kim, MD, Non ASSR Member
BK Choi, MD, Non ASSR Member
SH Lee, MD, Non ASSR Member
HW Chung, MD, Non ASSR Member
JH Cha, MD, Non ASSR Member

Scientific Poster

Exhibit Panels: 1

Purpose

The purpose of this study is to evaluate the usefulness of isotropic single-slab 3D Turbo Spin Echo (SPACE: Sampling Perfection with Application-optimized Contrasts using difference flip angle Evolutions) sequence compared with the fast spin echo (FSE) T2-weighted sequence for the evaluation of lumbar spine pathology.

Methods & Materials

We obtained both FSE T2-weighted and SPACE sagittal L-spine MR images in consecutive 26 patients simultaneously. The mean patient age was 54.4 years old (range: 19-71, 18 female and 8 male). All MR imaging were performed on a 1.5-MR unit (Magnetom Avanto; 1.5 Tesla System, Siemens Medical Solution, Germany) using a spine array coil along with a body coil. The image acquisition time was approximately four minutes in each image sequences. All MR images were independently reviewed and qualitatively analyzed by two musculoskeletal radiologists. The contrast-to-noise ratio (CNR), the signal-to-noise ratio (SNR) of nerve root vs perinural fat, nerve root vs intervertebral disc, subcutaneous fat vs back muscle, CSF vs spinal cord, intervertebral disc vs spinal cord and annulus fibrosus vs nucleus pulposus, and the diagnostic quality were graded with 5-points scale on both image sequences. We assessed the statistical differences of CNR, SNR, and the diagnostic quality between the two sequences using the Wilcox signed rank test; differences were considered significant when p< 0.05. Inter-observer agreement was obtained using the weighted Kappa statistics.

Results

The diagnostic quality of the SPACE images was superior to that of the FSEl T2-weighted images in both observers (p<0.05). The mean value of CNR and SNR was not statically significant (p>0.05). In the assessment of the CNR, SNR, and diagnostic quality, the k values poor to fair agreement ranged from -0.054 (p=0.88) to 0.354 (p=0.69), and the Kappa values were very low despite the relatively high overall agreement in both images due to the concentrated distribution of the agreement, which is referred to as the Kappa paradox.

Conclusion

SPACE images were superior in diagnostic quality as compared with FSE T2-weighted images, and statistically not significant in CNR and SNR. Therefore, SPACE images can replace FSE T2-weighted images and furthermore, the capability of 2D reformatted multiplane images in SPACE is unique and which is not comparable to FSE T2-weighted images.

References

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No financial Disclosures.