Biomechanic reflections in up-right MRI

SPINE RADIOLOGY Diagnostic and interventional 1 st Joint Meeting of ASSR and ESNR ROME, 9 11 JULY 2009 Biomechanic reflections in up-right MRI alessandra.splendiani@cc.univaq.it

Anatomy Spinal cord Nerve roots Vessels Ligaments Interv. disks

AJNR 1996 Occult lumbar lateral spinal stenosis in neural foramina subjected to physiologic loading Spine. 1997 Dynamic effects on the lumbar spinal canal: axially loaded CT-myelography and MRI in patients with sciatica and/or neurogenic claudication. Invest Radiol. 1998 Dynamic changes of the spinal canal in patients with cervical spondylosis at flexion and extension using magnetic resonance imaging. Acta Radiol. 1998 Axial loading of the spine during CT and MR in patients with suspected lumbar spinal stenosis. Radiology. 1998 Lumbar spine: quantitative and qualitative assessment of positional (upright flexion and extension) MR imaging and myelograpy. Spine. 1998 Biomechanical aspects of the subarachnoid space and cervical cord in healthy individuals examined with kinematic magnetic resonance imaging. AJNR 1998 Classification system based on kinematic MR imaging in cervical spondylitic myelopathy. Acta Radiol. 1999 Kinematic MR imaging in surgical management of cervical disc disease, spondylosis and spondylotic myelopathy. Skeletal Radiol. 2000 Are magnetic resonance flexion views useful in evaluating the cervical spine of patients with rheumatoid arthritis? Spine. 2001 The diagnostic effect from axial loading of the lumbar spine during computed tomography and magnetic resonance imaging in patients with degenerative disorders. Spine. 2001 Axially loaded magnetic resonance image of the lumbar spine in asymptomatic individuals. AJNR 2002 Measuring the axial rotation of lumbar vertebrae in vivo with MR imaging. Radiology. 2003 Cervical degenerative disease at flexion-extension MR imaging: prediction criteria. AJNR 2004 Axial loading during MR imaging can influence treatment decision for symptomatic spinal stenosis. Eur Radiol. 2005 Upright, weight-bearing, dynamic-kinetic MRI of the spine: initial results. Spine 2006 Dynamic degenerative lumbar spondylolisthesis: diagnosis with axial loaded magnetic resonance imaging. J Spinal Disord Tech. 2006 Open stand-up MRI: a new instrument for positional neuroimaging.

Abnormal magnetic resonance scans in asymptomatic subjects Weinreb JC. Prevalence of lumbosacral intervertebral disk abnormalities on MR images in pregnant and asymptomatic nonpregnant women. Radiology 1989 Boden SD. Abnormal magnetic resonance scans of the lumbar spine in asymptomatic subjects. J Bone Joint Surg Am 1990 Jensen MC. Magnetic resonance imaging of the lumbar spine in people without low back pain. N Engl J Med 1994 Boos N. The diagnostic accuracy of magnetic resonance imaging, work perception, and psychosocial factors in identifying symptomatic disc herniations. Spine 1995. Stadnik TW. Annular tears and disk herniation: prevalence and contrast enhancement on MR images in the absence of low back pain and sciatica. Radiology 1998. Weishaupt D. MR imaging of the lumbar spine: disk extrusion and sequestration, nerve root compression, endplate abnormalities and osteoarthritis of the facet joints are rare in asymptomatic volunteers. Radiology 1998 High percentage of false-negative with CT and MR imaging Kent DL. Diagnosis of lumbar spinal stenosis in adults: Metaanalysis of the acurancy of CT,MR and myelography.ajr 1992. Schönström N Dynamic changes in the dimensions of the lumbar spinal canal: an experimental study in vitro. J Orthop Res 1989 Nowicki B. Effect of axial loading on neural foramina and nerve roots in the lumbar spine. Radiology 1990; Willen J, Danielson B, Gaulitz A, Niklason T, Schánstrám N, Hansson T. Dynamic effects on the lumbar spine: axially loaded CTmyelography and MRI in patients with sciatica and/or neurogenic claudication. Spine 1997 Nowicki BH, Haughton VM, Schmidt TA, et al. Occult lumbar lateral spinal stenosis in neural foramina subjected to physiologic loading. AJNR Am J Neuroradiol 1996 Wildermuth S. Lumbar spine: quantitative and qualitative assessment of positional (upright flexion and extension) MR imaging and myelography. Radiology 1998

Upright and dynamic MR : why? 1. spinal curves not influenced by supine position 2. true ponderal/postural study 3. normal or abnormal segmental mobility Biomechanics of the spine

Functional Spinal Unit Neighbouring vertebrae Intervertebral disk Facet joints and capsules Ligaments Segmental muscles Simultaneous movements along two or more axes

1.Physiological Curvatures Resistance = Elasticity

1.Physiologic Curvatures Increasing of Curvatures Lordosislumbar angle and lumbarsacral angle recumbent Upright

Lordosis-lumbar angle Angle (~50 ) THE JOURNAL OF BONE AND JOINT SURGERY 1985 THE EFFECT OF POSTURE ON THE LUMBAR SPINE M. A. ADAMS, W. C. HUTTON

Lordosis-lumbar angle Quantification of changes in 50 asymptomatic subjects 50% male 50% female, double linded by 2 different radiologists* - ANGLE OF LUMBAR LORDOSIS INCREASE Clinostatismo Ortostatismo 38 37 36 35 34 33 32 31 30 29 1 Clinostatismo 32,02 Ortostatismo 37,74 *personal data Work in progress

> Lumbar sacral Angle (120-135 ) THE JOURNAL OF BONE AND JOINT SURGERY 1985 THE EFFECT OF POSTURE ON THE LUMBAR SPINE M. A. ADAMS, W. C. HUTTON

Angle of Lumbar Sacral Lordosis Quantification of changes in 50 asymptomatic patients 50% male 50% female, 35 45 age* ANGLE OF SACRAL LORDOSIS INCREASE 138,5 138 137,5 137 136,5 Clinostatismo Ortostatismo 136 135,5 135 1 Clinostatismo 137,54 Ortostatismo 138,46 * Personal data Work in progress

2. Physiological Conditions Reduction of intervertebral space Expansion of the thecal sac Reduction in volume of the epidural plexus recumbent upright

Increased dural sac diameter Stevin s law: The pressure of a fluid column is proportional to the column heigh P h = δ g h P hydrostatic = strenght/area Pascal s law: Pressure applied to a liquid surface is transmitted to all directions with same intensity and always perpendicular to the streght applied.

Physiological Conditions Quantification of changes in 50 asymptomatic patients 50% male 50% female, 35 45 age* > Dimension of the dural sac measured in mm 2 170 165 160 155 150 145 140 135 1 Clinostatismo 147,796 Ortostatismo 166,424 Clinostatismo Ortostatismo * Personal data Work in progress

Effects of loading: the signal of nucleus polposus decreases Nachemsen AL. Spine 1; 59-71, 1976 semi permeable membrane The water content of the disk changes under the opposed actions of hydrostatic and osmotic pressure. Rabischong P 1989 Anatomie functionelle du rachis et de la moelle Resnick D et al 1995 Diagnosis of bone and joint disorders.

Effects of loading: the signal of vertebral endplates increases recumbent upright

PATHOLOGY 1. Altered spinal elasticity 2. Changes in disk pathology 3. Ligament and joint compromission 4. Instability

recumbent 1.Altered elasticity Spine J 2001 The relationship between disc degeneration and flexibility of lumbar spine. Tanaka N, An HS, Lim TH, Fujiwara A... BMC Musculoskelet Disord. 2007 Segmental lumbar mobility in individuals with low back pain: in vivo assessment during manual and selfimposed motion using dynamic MRI Kornelia Kulig, et al uprigth

Functional Spinal Unit Neighbouring vertebrae Intervertebral disk Facet joints and capsules Ligaments Segmental muscles This kinetic MR imaging analysis showed that the lumbar functional unit with more disc degeneration, FJO, and LFH had abnormal sagittal plane translation and angulation. These findings suggest that abnormal segmental motion noted on kinetic MR images is closely associated with disc degeneration, FJO, and the pathological characteristics of interspinous ligaments, ligamentum flavum, and paraspinal muscles. Kinetic magnetic resonance imaging analysis of abnormal segmental motion of the functional spine unit. Kong MH, Hymanson HJ, Song KY, Chin DK, Cho YE, Yoon do H, Wang JC. J Neurosurg Spine. 2009 Apr;10(4):357-65.

2.DISK PATHOLOGY 1 Pivot of balance 2 Load resistance 3 Muscular strength 1 2 3

For 11% patients not seen with normal in supine or <3 position mm of disc bulge in neutral, 19.46% demonstrated an increase in herniation to >3 mm bulge in increase in volume in 72% extension, and 15.29% demonstrated an increase to >3 mm bulge in reduce flexion. volume in 18% Ferreiro Perez A, et al. Evaluation of intervertebral dic herniation and hypermobile intersegmental instability in Symptomatic adult patients undergoing recumbent and upright MRI of the cervical and lumbar spine. Eur J Radiol 2007 Jun; 62:444-8 Missed lumbar disc herniations diagnosed with kinetic magnetic resonance imaging. Zou J, Yang H, Miyazaki M, Wei F, Hong SW, Yoon SH, Morishita Y, Wang JC. Spine. 2008 Mar 1;33(5):E140-4

CHANGES IN SIZE OF DISK HERNIATION 30 1 CHANGES IN SIZE OF DISK HERNIATION 17 13 30 20 10 13 17 0 NO MODIFICATIONS FROM THE SUPINE TO THE UPRIGHT POSITION 12 = hypointense 5 = variously hyperintense YES MODIFICATIONS FROM THE SUPINE TO THE UPRIGHT POSITION 13 = VARIOUSLY HYPERINTENSE

CONCLUSION In 45% of disk herniations we had increase in the upright position 100% of disk herniations that show increase, present a residual of hydration In patients with modified disk herniation, we have hypomobility of the spine and increase of lumbar sacral angle All patients with high intensity herniation have a reduction of thickness of intersomatic discs. Upright MRI of disk herniation: status and changes in size under pysiological load MV Di Fabio, A. Splendiani et all. ECR 2008, Vienna 7-9 march 2008

CHANGES IN SIZE OF DISK HERNIATION

3.Function of ligaments to be in opposition to one to the others to protect the joints, disc and cord by restricting motion within physiological limits to transform high forces (load, speed) as energy absorbed 1 ALL 2 PLL 3 Lig. flavum 4 Lig. interspinosum 5 Lig. supraspinosum 1 ALL 2 PLL 3 Lig. Flavum 4 Lig. Interspinosum 5 Lig. supraspinosum

extension Neutral flexion

The use of flexion-extension magnetic resonance imaging for evaluating signal intensity changes of the cervical spinal cord. Guppy KH, Hawk M, Chakrabarti I, Banerjee A. Neurosurg Spine. 2009 Apr;10(4):366-73

Stenosis: a dynamic concept

Spine. 2008 Jan The effect of body position and axial load on spinal canal morphology: an MRI study of central spinal stenosis. Madsen R, Jensen TS, Pope M, Sørensen JS, Bendix T.

Association with disk degeneration and facet joint osteoarthritis determine neural foramina stenosis on the response to loading. Preliminary result using dedicated upright MR system. (RSNA 2008) upright recumbent

Conclusion This study supports the concept of dynamic foramina stenosis as demonstrated by anatomical studies

Materials and methods Post-processing MPR reconstruction by 3D HYCE Axial 1mm thick (supine / upright) parallel to vertebral endplate in sagittal and coronal plane Protocol G-Scan (Esaote Italy)

RESULTS Disk pathology Yes 30 Facet pathology Yes 30 Foramina Stenosis Yes (p<.0001)

RESULTS Disk pathology Yes 30 Facet pathology Yes 30 Foramina Stenosis Yes (p<.0001)

Spine. 2007 Does lumbar facet fluid detected on magnetic resonance imaging correlate with radiographic instability in patients with degenerative lumbar disease? Rihn JA et al Spine. 2007 The significance of increased fluid signal on magnetic resonance imaging in lumbar facets in relationship to degenerative spondylolisthesis. Chaput C et al

Instability Difficult to define: questionair by Fiedler : 30 experts quoted 30 different definitions The loss of ability of the spine under physiologic loads to maintain relationships between vertebrae in such a way that there is neither damage nor susseguent irritation to the spinal cord or nerve roots and, in addition, there is no development of incapacitating deformity or pain due to structural changes (White and Panjiabi) Instability implies the partial or complete loss of one or both function of the spine : Support of the head and body Protection of spinal cord and nerve roots (Denis F)

extension neutral flexion LYSTESIS overall diagnostic gain: 15% missed in supine exam: 31% modified in upright: 54% Ferreiro Perez A, et al. Evaluation of intervertebral dic herniation and hypermobile intersegmental instability in Symptomatic adult patients undergoing recumbent and upright MRI of the cervical and lumbar spine. Eur J Radiol 2007 Jun; 62:444-8

Instability

Dynamic and upright MR : disadvantages Low field Motion artefacts due to pain Scan time

FSE T2 Sag recumbent FOV = 320*320 MATRIX = 256*224 NEX = 4 Slices = 11 Tickhness= 4.0 TR/TE = 3300/120 Time= 6:42 FSE T2 Sag upright FOV = 330*330 MATRIX = 256*224 NEX = 3 Slices = 11 Tickhness= 4.0 TR/TE = 3300/120 Time= 5:03

NEW SEQUENCES for G-Scan in Spine FAST SPIN ECHO STIR 3D HYCE enhanced myelographic contrast

Dynamic and upright MR : advantages True upright spinal curvature Revelation of occult degenerative spinal disease Unmasking of kinetic-dependent disease Overall Diagnostic Gain= 48-62% Personal unpublished data Ferreiro Perez A, et al. Evaluation of intervertebral dic herniation and hypermobile intersegmental instability in Symptomatic adult patients undergoing recumbent and upright MRI of the cervical and lumbar spine. Eur J Radiol 2007 Jun; 62:444-8

1 st Joint Meeting of ASSR and ESNR ROME, 9 11 JULY 2009