Lumbosacral Transition Vertebra -The Holy Grail in Spine Imaging-Survival Mantras for the resident.

Transcription

1 Lumbosacral Transition Vertebra -The Holy Grail in Spine Imaging-Survival Mantras for the resident. Poster No.: C-1024 Congress: ECR 2017 Type: Educational Exhibit Authors: R. M. S. V. Vadapalli, R. Mulukutla, S. K.Reddy, L. K. balla, A. Jaiswal, S. kalavacherla, A. S. Vadapalli ; Hyderabad/IN, Hyderabad, Ap/IN, Secunderabad/IN, Sanfransisco/US, Pune, Maharastra/IN Keywords: Anatomy, Musculoskeletal bone, Musculoskeletal spine, Conventional radiography, CT, MR, Diagnostic procedure, Developmental disease, Inflammation DOI: /ecr2017/C-1024 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 38

2 Learning objectives 1.To Elucidate Imaging features of Lumbo sacral Transition vertebra(lstv) and its various sub types and classification. 2.To highlight various morphologicaal and localization mantras for loxcalization of L5. 3.Illustrate the CT and MR Imaging features of LSTV and clinico pathological correlates and their significance Background L.LSTVs are congenital spinal anomalies defined as either sacralization of the lowest lumbar segment or lumbarization of the most superior sacral segment of the spine.. LSTVs are common in the general population, with a reported prevalence of 4%-30%anomalies defined as either sacralization of the lowest lumbar segment or lumbarization of the most superior sacral segment of the spine.. LSTVs are common in the general population, with a reported prevalence of 4%-30%. Sacralization: Sacralization refers to a cranial shift where the last lumbar vertebra assumes sacral characteristics and frequently becomes incorporated in to sacrum. The degree of morphologic variation of these segments ranges from L5 vertebrae with broadened elongated transverse processes to complete fusion to the sacrum Depending on the direction of the shift, an individual may end up with either an extra lumbar segment or one fewer segment, which can have significant biomechanical and clinical implications T Page 2 of 38

3 Images for this section: Page 3 of 38

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5 Fig. 1: Lumbarization: image demonstrates "squaring" of a lumbarized S1 vertebral body Additionally, there is a fully-sized lumbar type disk between S1 and S2, compared with the characteristic vestigial disk typically seen at this level. (Red Arrow) Page 5 of 38

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7 Fig. 2: Sacralization: sag reformat showing Note the decreased height between the sacralized L5 vertebral body and S1 ( Arrow), compared with the normal height typically seen at this level. Page 7 of 38

8 Findings and procedure details Imaging: Radiography: Ferguson radiographs: they have been classically described as being best imaged on Ferguson radiographs (AP radiographs angled cranially at 30 ).\The Classification of LSTV on Plain Radiographs(Ferguson Radiography) Castellvi et al described a radiographic classification system identifying 4 types of LSTVs on the basis of morphologic characteristics -Type I :unilateral (Ia) or bilateral (Ib) dysplastic transverse processes, measuring at least 19 mm in width (craniocaudad dimension)). -Type II exhibits incomplete unilateral (IIa) or bilateral (IIb) lumbarization/ sacralization with an enlarged transverse process that has a diarthrodial joint between itself and the sacrum CT: superior spatial resolution, CT is the best imaging technique for characterization of LSTVs. These anomalies are usually identified incidentally because CT is not typically indicated solely to identify LSTVs due to radiation concerns, nor is it the preferred imaging technique used to evaluate patients with nontraumatic low back pain The S1 vertebral segment can show varying degrees of lumbarization - formation of an anomalous articulation rather than fusion to the remainder of the sacrum - well-formed lumbar-type facet joints - a more squared appearance in the sagittal plane - a well-formed fully-sized disk, rather than the smaller-sized disk typically seen between S1 and S2. Type I Lumbosacral transition vertebra includes unilateral (Ia) or bilateral (Ib) dysplastic transverse processes, measuring at least 19 mm in width (craniocaudad Page 8 of 38

9 dimension). If the ilio lumbar ligaments are short and broad. (Red Arrows)CT: superior spatial resolution, CT is the best imaging technique for characterization of LS MRI: the classification and numbering of LSTVs are most problematic on MR imaging due to the following: -limited imaging of the thoracolumbar junction, -Problems in identification of the lowest rib-bearing vertebral body, -Challenges in differentiation between thoracic hypoplastic ribs and enlarged lumbar transverse processes -Dilemma for radiologists because they may have to read a lumbar spine MR imaging examination in isolation without the benefit of other imaging such as spine radiographs to help correctly identify and enumerate LSTVs. The importance of Correct Identification of LSTV: -Inaccurate identification may lead to surgical and procedural errors and poor correlation with clinical symptoms. -the relationship of low back pain and LSTV, termed "Bertolotti Syndrome: Symptoms can originate from the anomalous articulation itself, the contralateral facet joint (when unilateral), instability and early degeneration of the level cephalad to the transitional vertebrae, and nerve root compression from hypertrophy of the transverse process Nicholson et al described a decreased height on radiographs of the disk between a lumbar transitional segment and the sacrum compared with the normal disk height between L5 and S1. Similarly, it has been observed that when a lumbarized S1 is present, the disk space between S1 and S2 is larger than the rudimentary disk that is most often seen in spines without transitions Where is the L5? : The Numbering Technique: Two key check points in a radiologist's Spine reporting check list include: -Is there a LSTV -accurate numeric identification of the vertebral segments on MR imaging Page 9 of 38

10 These are essential before surgery Radiography: Radiographs of the entire spine allow the radiologist not only to count from C2 inferiorly but also to differentiate hypoplastic ribs from lumbar transverse processes - enabling counting of the number of thoracic segments and correct identification of the L1 vertebral body -determining the correct numeric assignment of the LSTV is possible -It is Uncommon in clinical Practice to Use Whole Spine Radiographs (Exception being the Scoliotic Spines). -commonly lumbar spine radiographs alone are available and some times Patiens do not carry them to a MRI Department Caveats: - Not usually done. - difficult to differentiate hypoplastic ribs from transverse processes at the thoracolumbar junction. -thoracolumbar transitions and segmentation anomalies add further complexity to the counting process MRI: A):Counting from C2 to Locate L1 6 Hahn et al first described the use of a sagittal cervicothoracic MR localizer. Most of the Preent MRI whole Body systems have Phased Array Spine coils with large FOV imaging either giving one shot whole Spine Localizer or by doing a Multi station T2 sagittal Imaging with automatic Clipping of the images accurately(mr Pasting: IN GE Health care,spine Compose in Siemens and Mobiview in Philips Health care). This solves the common problems of identifying of L1 or the Thoracic Lumbar Junction accurately. B) Location of Ilio Lumbar Ligaments for Accurate Counting of LSTV Page 10 of 38

11 -technique used to correctly number an LSTV is locating the iliolumbar ligaments, -they reliably arise from the L5 transverse processes The iliolumbar ligament functions to restrain flexion, extension, axial rotation, and lateral bending of L5 on S1Visualized as a low-signal-intensity structure on both axial T1- and T2-weighted MR images as a single or double band extending from the transverse process of L5 to the posteromedial iliac crest. On CT : Iliolumbar Ligaments are well Identified. When an iliolumbar ligament was seen to arise above the LSTV, then the vertebral body with the iliolumbar ligament was labeled L5 and the LSTV, as S1. Hughes and Saifuddin et al labeled an LSTV as L5 when no iliolumbar ligament was identified at the level above Clinical Significance of LSTV: There are many factors associated with LSTV that may potentially be the source of pain: 1) disc degeneration, 2) disc prolapse, 3) spinal stenosis, 4) nerve root compression, 5) olisthesis, 6) sacroiliac joint pain, 7) muscle, tendon, or ligament strain or sprain, 8) chemical irritation, 9) vertebral collapse, and 10) damage to other nearby structures receiving innervation. A)-Bertolotti Syndrome: Bertolotti syndrome, the association between an LSTV and low back pain. It is controversial and has been both supported and disputed since Bertolotti first described it in the low back pain of this syndrome is currently thought to be of varying etiologies, subsequently arising from different locations:. ) disk, spinal canal, and posterior element pathology at the level above a transition 2) degeneration of the anomalous articulation between an LSTV and the sacrum 3) facet joint arthrosis contralateral to a unilateral fused or articulating LSTV 4) extraforaminal stenosis secondary to the presence of a broadened transverse process Page 11 of 38

12 In most of the literature that supports Bertolotti syndrome, the implicated transitional segments are Castellvi types II-IV Type I LSTV is associated with Short broad Ilio Lumbar Ligaments short and broad iliolumbar ligaments lend a protective effect to the L5-S1 disk space and potentially destabilize the L4-L5 level. There may be an association of such iliolumbar ligament morphology with broadened long transverse processes (Castellvi type I) B: increased incidence of disk pathology above LSTVs (Luoma et al, Epstein et al) increased risk of early degeneration in the upper disk in young patients C. Transitional vertebrae likely affect the normal biomechanics of the lumbar spine: The lack of mobility at a fused transitional level or the decreased mobility at a partially fused or anomalously articulating vertebra lends stabilization to this level A decreased prevalence of disk pathology was found in the disk below the transitional vertebral body due to alterations in Biomechanics by aberrant joints between LST and Sacrum. D.) Surgeon's Night Mare: Wrong-Level Spine Surgery most wrong-level spine surgery occurs in patients with variant spine anatomy, including LSTVs Hence Accurate Localization of Level of Disease and Accurate Numeric labeling is essential before any intervention or Surgical procedure is performed to Alleviate these risks Images for this section: Page 12 of 38

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14 Fig. 3: Sacralization of L5 Page 14 of 38

15 Fig. 4: Partially Sacralized L5 on STIR Coronal Page 15 of 38

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18 Fig. 5: Whole spine Sacralization of L5: Counting from C2 level to accurately identify L5 Page 18 of 38

19 Fig. 6: STIR coronal showing a Type II b lumbo sacral transition vertebra with both transverse processes of L5 articulating with Sacrum. (Red Arrows) Fig. 7: CT coronal reformat showing Type II Transition vertebra exhibits incomplete unilateral fusion (II a) Page 19 of 38

20 Fig. 8: 3D CT with Volume rendering: bilateral (IIb)nlumbarization/sacralization with an enlarged transverse process that has a diarthrodial joint between itself and the sacrum Page 20 of 38

21 Fig. 9: 3D CT Volume rendering :Type II B Transition vertebra Page 21 of 38

22 Fig. 10: LSTV Type IIA : 3D CT Volume Rendering Page 22 of 38

23 Fig. 11: LSTV Type IIA : 3D CT Volume Rendering Page 23 of 38

24 Fig. 12: CT coronal reformat and 3D CT showing Type III LSTV describes unilateral (IIIa) or bilateral (III b) lumbarization/sacralization with complete osse- ous fusion of the transverse process(es) to the sacrum. Associated with Betrolitti Syndrome. (Blue Arrows) Page 24 of 38

25 Fig. 13: CT coronal reformat CT showing Type III LSTV describes bilateral (III b) Ilio Lumbar ligaments are seen arising from fused L5 Page 25 of 38

26 Fig. 14: CT Appearances of Ilio Lumbar ligaments coursing from L5 trasnverse processes and coursing to Postero superior iliac crest. (Blue Arrows) (Red Arrows) Page 26 of 38

27 Fig. 15: Both ilio Lumbar ligaments identified on CT ( and MRI studies as soft tissue bands (on CT) and T1 and T2 hypo intense structures (MRI) coursing from transverse process of L5 to the Posterior superior iliaccrest. Hence, L5 is accurately identified. ( Red Arrows) Fig. 16: Both ilio Lumbar ligaments identified on CT ( and MRI studies as soft tissue bands (on CT) and T1 and T2 hypo intense structures (MRI) coursing from transverse process of L5 to the Posterior superior iliaccrest. Hence, L5 is accurately identified. ( Red Arrows) Page 27 of 38

28 Fig. 17: Both ilio Lumbar ligaments identified on CT ( and MRI studies as soft tissue bands (on CT) and T1 and T2 hypo intense structures (MRI) coursing from transverse process of L5 to the Posterior superior iliaccrest. Hence, L5 is accurately identified. ( Red Arrows) Page 28 of 38

29 Fig. 18: Bertolitti"s syndrome: Bertolotti Syndrome: Bertolotti syndrome, the association between an LSTV and low back pain. It is controversial and has been both supported and disputed since Bertolotti first described it in 1917.the low back pain of this syndrome is currently thought to be of varying etiologies, subsequently arising from different locations:. Page 29 of 38

30 Fig. 19: Bertolitti"s syndrome: Bertolotti Syndrome: Bertolotti syndrome, the association between an LSTV and low back pai Page 30 of 38

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32 Fig. 20: T1 Sagittal MRI showing Lumbosacral Transition vertebra with sacralization of S1 Page 32 of 38

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34 Fig. 21: STIR coronal : marrow edema at the articular surfaces sacralized L5 with sacrum seen hyper intense signal on either side right>left. Bertolitti's Syndrome. Page 34 of 38

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36 Fig. 22: STIR coronal : marrow edema at the articular surfaces sacralized L5 with sacrum seen hyper intense signal on either side right>left. Bertolitti's Syndrome. Page 36 of 38

37 Conclusion This exhibit elucidates multimodality imaging features with tips to localize Lumbosacral Transition Vertebra(LSTV) and its types on Radiography,CT and MRI clinical significance and Pathological correlates. Personal information References. -Konin GP, et al;lumbosacral transitional vertebrae: classification, imaging findings, and clinical relevance. AJNR Am J Neuroradiol 2010;31(10): Bron et al. The clinical significance of lumbosacral transitional anomalies. Acta Orthop Belg 2007;73: Castellvi A et al, Lumbosacral transitional vertebrae and their relationship with lumbar extradural defects. Spine 1984;9: Elster AD: Bertolotti's syndrome revisited: transitional vertebrae of the lumbar spine. Spine 1989;14: Bertolotti M Contributo alla conoscenza dei vizi differenzazione regionle delrachid con speciale riguardo all'assimilazione sacrale edlla v lombare. La Radiologia Medica 4: Lorenzo Nardo et al. Lumbosacral Transitional Vertebrae: Association with Low Back Pain Radiology : Numbering of vertebrae on MRI using a PACS cross-referencing tool Acta Radiol : Mark A. Palumbo, et al.wrong Site Spine Surgery J Am Acad Orthop Surg May 2013 ; 21: Page 37 of 38

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