A Feasibility Study Using Diffusion

Serviço de Cirurgia da Coluna - Hospital Lifecenter
A Feasibility Study Using
Diffusion-Weighted Magnetic Resonance (DW-MR)
Neurography of the Lumbar Plexus in the Preoperative
Planning of Lateral Access Lumbar Surgery
Cristiano M Menezes; Luciene M Andrade;; Carlos F. Herrero; Helton A
Defino; W. Blake-Rodgers, Marcello N-Barbosa,. Spine Surgery Department
Hospital Lifecenter/ Ortopédico
Axial Centro de Imagem
Belo Horizonte/ MG
Faculdade Medicina Ribeirão Preto USP
Brazil
Spine Midwest , St Mary’s Health Center, Jefferson
City, USA
Serviço de Cirurgia da Coluna - Hospital Lifecenter
Disclosures
•  Cristiano Menezes, M.D.
•  Past and Present – Medtronic (e); Nuvasive (e)
Serviço de Cirurgia da Coluna - Hospital Lifecenter
MRI
•  Fat-suppressed T2-weighted - nerve anatomy.
•  A major disadvantage is the similar signal intensity of
nerves and vessels - discrimination difficult and time
consuming.
Regev. SPINE Volume 34-12, 1330–1335. 2009
Serviço de Cirurgia da Coluna - Hospital Lifecenter
Objective
• The purpose of this study is to introduce and
assess 3DW-MR neurography for imaging of the
lumbar plexus in the pre-op planning of lateral
access surgery.
Serviço de Cirurgia da Coluna - Hospital Lifecenter
Methods
•  Ninety-four patients (188 sides) with degenerative
spinal disorders and history of low back pain
underwent a 3DW-MR examination
•  In order to evaluate their lumbar plexus anatomy and
its relation with L3L4 and L4L5 disc spaces, as well as
the superior third of the L5 vertebral body.
Serviço de Cirurgia da Coluna - Hospital Lifecenter
Methods
•  Images were reconstructed in axial plane using high-resolution 10 mm
MIP* slabs over the disc space
•  and 22 mm MIP slabs in L3-L4/ L4-L5 interspace to mimic the
working zone of standart lateral access retractors
•  L4 spinal nerve and FN position were analyzed relative to L45 disc –
confirmed in sagittal plane (30 mm slab)
•  The area between the anterior and posterior edges of the disc space
was divided into 4 zones (axial and sagittal planes)
* Maximum Intension Projection
Uribe J Neurosurg Spine
13:260–266, 2010
Serviço de Cirurgia da Coluna - Hospital Lifecenter
T2 weighted axial magnetic resonance
imaging (MRI) showing L4-5
intervertebral spaces with standard
psoas muscule anatomy (A,B). MR
neurography in the same patient
demonstrating anteriorization of the
lumbar plexus to zone 2 on the right
(C,D).
Serviço de Cirurgia da Coluna - Hospital Lifecenter
Results
•  46 female/ 48 male
•  17 to 83 years-old (mean 48,6)
•  In all subjects the plexus was succesfully mapped
•  L2/L3 and L4 roots coalesced into the FN bellow the
L4L5 disc space.
Serviço de Cirurgia da Coluna - Hospital Lifecenter
Serviço de Cirurgia da Coluna - Hospital Lifecenter
Serviço de Cirurgia da Coluna - Hospital Lifecenter
Serviço de Cirurgia da Coluna - Hospital Lifecenter
Conclusion
•  DW-MR neurography appears to afford a noninvasive
method of mapping the lumbar plexus preoperatively.