J Korean Soc Radiol.  2013 Jan;68(1):49-55.

Comparison of Different 3.0 T Magnetic Resonance Sequences for Lumbosacral Plexus and Its Branches: Preliminary Study

• Lee H
• Lee JW
• Lee JH
• Kang HS

Abstract

PURPOSE
To prospectively evaluate four magnetic resonance sequences [ProSet, fluid attenuation inversion recovery (FLAIR), balanced turbo field echo (B-TFE), T2 Drive] for the lumbosacral plexus and its branches.
MATERIALS AND METHODS
Ten healthy volunteers who underwent four MRI sequences on lumbosacral area were evaluated for image quality (1 to 5; 1 = poor, 5 = excellent), the number of visualized bilateral spinal nerves from L2 to S1, the overlapping vessels obscuring the plexus (1 = many, 2 = some, 3 = few), and image quality defining spinal nerves (0 = nonvisualized, 1 = poor, 2 = moderate, 3 = good).
RESULTS
The ProSet (mean = 4.2, range 3-5) and B-TFE (mean = 3.7, range 3-5) showed better image quality than others. The number of visualized spinal nerves was the largest on ProSet image (mean = 9.2, range 8-10). FLAIR (mean = 2.1, range 1-3) and T2 Drive sequences (mean = 2.1, range 1-3) discriminated the nerves well from the vessels. The main branches of the lumbosacral plexus were well visualized on both ProSet (mean = 2.9, range 2-3) and FLAIR images (mean = 2.6, range 1-3). All of these were statistically significant.
CONCLUSION
ProSet is the best sequence in the evaluation of the lumbosacral plexus and its major branches while FLAIR can be a complementary sequence for the evaluation of nerves overlapping vascular structures.

MeSH Terms

Lumbosacral Plexus
Magnetic Resonance Spectroscopy
Magnetics
Magnets
Prospective Studies
Spinal Nerves

Figure

• 

  Fig. 1 Coronal reformatted images of four different sequences of 29-year-old healthy male. Spinal nerves and dorsal root ganglia (arrows) are seen on images of four different sequences, and those are best visualized on ProSet image. The image quality for spinal nerve visualization on ProSet image (A) and B-TFE image (C) are better than those on FLAIR image (B) and T2 Drive image (D). Note.-B-TFE = balanced turbo field echo, FLAIR = fluid attenuation inversion recovery

• 

  Fig. 2 Oblique sagittal reformatted images of four different sequences of 29-year-old healthy male. Vessels could pass close by the pathway of spinal nerves. Some portions of the nerves are obscured by the vessels on ProSet image (A), B-TFE image (C) and T2 Drive image (D) (arrows on A, C and D). However, the nerves on FLAIR image (B) are well-discriminated from the adjacent vessels (arrow on B). Note.-B-TFE = balanced turbo field echo, FLAIR = fluid attenuation inversion recovery

• 

  Fig. 3 Oblique coronal reformatted images of four different sequences of 32-year-old healthy male. Tibial nerve (arrows) and sciatic nerve (arrowheads) are relatively well demonstrated on ProSet and FLAIR images (A: ProSet image, B: FLAIR image, C: B-TFE image, D: T2 Drive image). Note.-B-TFE = balanced turbo field echo, FLAIR = fluid attenuation inversion recovery

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  Fig. 4 Oblique sagittal reformatted images of four different sequences of 30-year-old healthy male. FLAIR image is the best sequence to discriminate femoral nerve (arrows) from surrounding structures (A: ProSet image, B: FLAIR image, C: B-TFE image, D: T2 Drive image). Note.-B-TFE = balanced turbo field echo, FLAIR = fluid attenuation inversion recovery

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  Fig. 5 Oblique sagittal reformatted images of four different sequences of 28-year-old healthy male. On ProSet sequence, obturator nerve (arrows) is well-demarcated by surrounding low signal fat plane as thin and intermediate signal structure. On T2 Drive image, the obturator nerve is not distinguished from surrounding fat plane (A: ProSet image, B: FLAIR image, C: B-TFE image, D: T2 Drive image). Note.-B-TFE = balanced turbo field echo, FLAIR = fluid attenuation inversion recovery

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