Real-Time Ultrasound/MRI Fusion for Suprasacral Parallel Shift Approach to Lumbosacral Plexus Blockade and Analysis of Injectate Spread: An Exploratory Randomized Controlled Trial

Figure 4

MRI of one subject visualizing spread of lidocaine-epinephrine added diluted contrast (magenta arrow) primarily posterior to the psoas major muscle (PPM), that is, in the retropsoas subcompartment, with minor seeping into the fascial plane between the anterior and posterior (red arrow) lamina of the PMM that contains the lumbar plexus. (a) Sagittal plane. (b) Axial plane. (c) Coronal plane. L5, fifth lumbar vertebral body; Line (blue), position of coronal plane; Line (orange), position of sagittal plane; Line (purple), position of axial plane; S, sacral ala.

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