(BQ) Part 1 book Diagnostic imaging spine presentation of content: Congenital and genetic disorders, scoliosis and kyphosis, vertebral column, discs, and paraspinal muscle, cord, dura, and vessels, degenerative diseases, spondylolisthesis and spondylolysis, inflammatory, crystalline, and miscellaneous arthritides.
ii Jeffrey S Ross, MD Neuroradiology Barrow Neurological Institute St Joseph’s Hospital Phoenix, Arizona Kevin R Moore, MD Pediatric Neuroradiology Intermountain Pediatric Imaging Primary Children’s Hospital Salt Lake City, Utah iii 1600 John F Kennedy Blvd Ste 1800 Philadelphia, PA 19103-2899 DIAGNOSTIC IMAGING: SPINE, THIRD EDITION ISBN: 978-0-323-37705-8 Copyright © 2015 by Elsevier All rights reserved No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein) Notices Knowledge and best practice in this field are constantly changing As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility With respect to any drug or pharmaceutical products identified, readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications It is the responsibility of practitioners, relying on their own experience and knowledge of their patients, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein Publisher Cataloging-in-Publication Data Diagnostic imaging Spine / [edited by] Jeffrey S Ross and Kevin R Moore 3rd edition pages ; cm Spine Includes bibliographical references and index ISBN 978-0-323-37705-8 (hardback) Spine Imaging Handbooks, manuals, etc Diagnostic imaging I Ross, Jeffrey S (Jeffrey Stuart) II Moore, Kevin R III Title: Spine [DNLM: Spinal Diseases diagnosis Handbooks Magnetic Resonance Imaging Handbooks Spine anatomy & histology Handbooks WE 725] RD768.D535 2015 616.7/30754 dc23 International Standard Book Number: 978-0-323-37705-8 Cover Designer: Tom M Olson, BA Cover Art: Laura C Sesto, MA Printed in Canada by Friesens, Altona, Manitoba, Canada Last digit is the print number: iv Dedications “Let the wise hear and increase in learning, and the one who understands obtain guidance.” Proverbs 1:5 -65 $ SURMHFW RI WKLV PDJQLWXGH UHƮHFWV WKH KDUG HƪRUWV of many underrecognized people I extend my deepest gratitude to all of you – thank you! 50 v vi Contributing Authors /XEGKD 0 6KDK 0' Associate Professor of Radiology Division of Neuroradiology University of Utah School of Medicine Salt Lake City, Utah %U\VRQ %RUJ 0' )DLUƬHOG &DOLIRUQLD -XOLD &ULP 0' Chief of Musculoskeletal Radiology Professor of Radiology University of Missouri at Columbia Columbia, Missouri &KHU\O 3HWHUVLOJH 0' 0%$ Clinical Professor of Radiology Cleveland Clinic Lerner College of Medicine Case Western Reserve University Cleveland, Ohio $ &DUO 0HUURZ 0' Corning Benton Chair for Radiology Education Cincinnati Children’s Hospital Medical Center Associate Professor of Clinical Radiology University of Cincinnati College of Medicine Cincinnati, Ohio vii viii Preface Welcome to the third edition of Diagnostic Imaging: Spine Five years have SDVVHG VLQFH WKH VHFRQG HGLWLRQ DQG HOHYHQ \HDUV KDYH ƮRZQ E\ VLQFH WKH ƬUVW HGLWLRQ ZDV SXEOLVKHG 7KLV HGLWLRQ LV D UHIUHVK ZLWK QHZ LPDJHV QHZ GLDJQRVHV DQG XSGDWHG WH[W DQG UHIHUHQFHV 7KH VDPH H[FHOOHQW $PLUV\V formatting is present, with individual diagnoses capable of standing alone but ZLWK D ORJLFDO LQWHJUDWLRQ ZLWKLQ WKH ODUJHU VHFWLRQV 7KH H\ )DFWV ER[ UHWDLQV its visual prominence at the beginning of each diagnosis, allowing for a quick scan of the most important bullet points when time is short (and when is it QRW" Ankylosing Spondylitis Definitions • Syndesmophyte: Paraspinous ligamentous or disc ossification bridging adjacent vertebral bodies IMAGING General Features • Location ○ Intervertebral discs ○ Synovial joints of spine: Facet, uncovertebral, costotransverse, costovertebral ○ Joints of axial skeleton ○ Tendon and ligament attachments (entheses) – Plantar fascia origin erosions common Radiographic Findings • Sacroiliac joints: Sacroiliitis ○ Bilaterally symmetric erosive arthropathy ○ Findings seen on iliac side of joint before sacral side ○ Early: Loss of definition of subchondral bone plate ○ Later: Erosions, widened joint space – Erosions often small, indistinct ○ Later: Sclerosis surrounding joint ○ Endstage: Fusion of joint • Vertebral bodies ○ Earliest: Squaring of vertebral bodies → corner erosions → "shiny corner" (corner sclerosis) ○ Later: Thin syndesmophytes bridge vertebrae ○ End stage: Widespread ankylosis ("bamboo spine") • Facet, uncovertebral joints ○ Erosions → fusion • Enthesopathy ○ Erosions, periosteal new bone formation at tendon and ligament attachments • Osteopenia CT Findings • Same findings as radiograph, but ↑ sensitivity MR Findings • Bone marrow edema: Low signal T1, high signal T2 and STIR ○ Sacroiliac joints ○ Corners of vertebral bodies, facet joints • Joint effusions • Erosions: Loss of subchondral bone plate, irregular margins of joint • Squaring of vertebral bodies • Ankylosis not a striking MR finding ○ Syndesmophytes are thin, low signal intensity on all sequences Imaging Recommendations • Best imaging tool ○ MR and CT have good sensitivity for sacroiliitis Imaging of Trauma in AS • C2, cervicothoracic junction, thoracolumbar junction ○ Often a hyperextension injury, involving all columns of spine DIFFERENTIAL DIAGNOSIS DISH • Bulky ossification of paraspinous ligaments • SIJs usually normal, rarely fused by bulky osteophytes Rheumatoid Arthritis • Ankylosis not a feature • Involves synovial joints, spares discs • Primarily in cervical spine Psoriatic Arthritis and Reactive Arthropathy • Bulky ossification of paraspinous ligaments • SIJ involvement often asymmetric Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides ○ Fracture may be through vertebral body or fused disc space ○ MR should be considered to exclude occult fracture, as these may be subtle secondary to osteopenia TERMINOLOGY Osteitis Condensans Ilii • Sclerosis adjacent to SIJ • Subchondral bone plate preserved, no erosions • Joint space normal or narrow Infection • Unilateral sacroiliitis PATHOLOGY General Features • Associated abnormalities ○ Pulmonary interstitial fibrosis, decreased chest excursion, uveitis, aortitis, aortic regurgitation ○ 90% of patients HLA-B27 positive CLINICAL ISSUES Presentation • Most common signs/symptoms ○ Pain centered over SIJs, back stiffness • Other signs/symptoms ○ Kyphotic deformity, fracture Treatment • Corticosteroids • Disease modifying agents (DMARDs): Tumor necrosis factor inhibitors, sulfasalazine, methotrexate ○ Early initiation of treatment helps prevent ankylosis DIAGNOSTIC CHECKLIST Image Interpretation Pearls • Normal SIJs preclude imaging diagnosis of AS SELECTED REFERENCES Navallas M et al: Sacroiliitis associated with axial spondyloarthropathy: new concepts and latest trends Radiographics 33(4):933-56, 2013 Campagna R et al: Fractures of the ankylosed spine: MDCT and MRI with emphasis on individual anatomic spinal structures AJR Am J Roentgenol 192(4):987-95, 2009 Braun J et al: Ankylosing spondylitis Lancet 369(9570):1379-90, 2007 547 Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides Ankylosing Spondylitis (Left) Coronal bone CT shows erosions and sclerosis at the C1-2 facet joints st There is extensive periosteal reaction (enthesopathy) surrounding the dens Occiput-C1 joints are fused ſt (Right) Sagittal bone CT shows fractures at C2 st and C7 ſt in a patient with AS Fractures in this population are often multilevel and difficult to see on CT because of osteopenia Fracture of the C7 spinous process alerts the radiologist to look for a fracture of the anterior column (Left) Sagittal T1WI MR shows the characteristically unimpressive MR appearance of syndesmophytes st At C34 the entire disc has ossified (Right) Sagittal T2WI MR in a different patient shows ligamentous ossification extending from the clivus to the thoracic spine st Note the upper thoracic kyphosis Spinal deformity in patients with AS may preclude use of a cervical MR coil, and flexible surface coils are often a better option (Left) Lateral radiograph in a 46-year-old woman shows fixed deformity from AS Vertebral bodies and facet joints are fused, with loss of cervical lordosis Thoracic kyphosis is severe, and the patient's chin was on her chest Spinal deformity of AS can be debilitating Patient also had limited chest expansion due to ankylosis of rib articulations (Right) Sagittal bone CT shows the same patient after extension osteotomy and posterior fusion A focal lordosis has been created at C6-7 ſt 548 Ankylosing Spondylitis Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides (Left) Anteroposterior radiograph shows SIJ sclerosis The subchondral bone plate is poorly defined, but erosions are subtle Sacroiliac joints are difficult to evaluate on radiograph CT or MR may be performed to improve early diagnosis and allow prompt DMARD treatment (Right) Lateral radiograph shows "shiny corner" sign st at L1 and L2 There is squaring of the vertebral body contour of T12-L3 AS initially involves the SIJs, then typically skips to the thoracolumbar junction (Left) Axial bone CT shows bilaterally symmetric sacroiliitis Small erosions st are seen with widening of the joint and reactive sclerosis Osteitis condensans ilii, in contrast, shows bone sclerosis without erosions or joint space widening (Right) Axial T2WI MR shows bilateral sacroiliac joint erosions st Bone marrow edema is slightly more prominent on the left As is typical, the erosions are more severe on the iliac side of the joint (Left) Anteroposterior radiograph shows fused SIJs ſt and bamboo spine Fracture of L4 is difficult to see because of severe osteopenia Hip arthroplasties were performed for advanced AS (Right) Lateral radiograph in the same patient shows hyperextension-type fracture of L4 The rigidity of the ankylosed spine renders it vulnerable to fracture Fractures may occur through syndesmophytes or, as in this case, through the vertebral body or ossified disc space 549 Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides CPPD KEY FACTS TERMINOLOGY TOP DIFFERENTIAL DIAGNOSES • Crowned dens syndrome: Pain due to CPPD deposition around dens • • • • • • • IMAGING • Soft tissue calcifications ○ Usually linear, occasionally globular ○ Seen in ligaments, discs, facet joint capsules, hyaline cartilage ○ Horseshoe-shaped calcification around dens • Erosions of odontoid process, vertebral endplates ○ Usually sharply demarcated, often corticated • MR findings nonspecific ○ Calcium usually not visible, low signal intensity on all sequences ○ Soft tissue mass surrounding dens ○ Erosions of dens, vertebral endplates (Left) Sagittal T1WI MR shows a large pseudopannus posterior to the odontoid process ſt with moderately severe effacement of the ventral thecal sac and mild mass effect upon the cervicomedullary junction A large degenerative cyst is present in the odontoid process (Right) Axial bone CT shows marked thickening of the retroodontoid soft tissues ſt with scattered calcifications that are consistent with a diagnosis of CPPD (Left) Sagittal bone CT shows severe CPPD at the craniocervical junction There is a large calcified mass posterior to the dens st and severe odontoid erosion Calcification is seen in the ligamentum flavum ſt and intervertebral discs (Right) Axial CTA study shows multiple punctate foci of calcification ſt within a large soft tissue mass posterior to the odontoid process, which causes cord compression 550 Degenerative disc disease Rheumatoid arthritis, adult Osteomyelitis, pyogenic Seronegative spondyloarthropathy Hemodialysis arthropathy Hyperparathyroidism Gout CLINICAL ISSUES • Chronic back pain • Acute attack of pain ± fever ± radiculopathy • Myelopathy due to cord compression DIAGNOSTIC CHECKLIST • CT useful in distinguishing from rheumatoid arthritis, which does not calcify CPPD Abbreviations • Calcium pyrophosphate dihydrate deposition (CPPD) disease Definitions • Pseudogout: Acute painful episode due to CPPD ○ Terms with "pseudo" should generally be abandoned in favor of CPPD • Crowned dens syndrome: Pain due to calcium pyrophosphate crystal deposition around dens IMAGING General Features • Abnormal signal intensity in vertebrae ○ Usually mild ○ Centered on disc ○ T1 findings often more prominent than on T2, STIR ○ Minimal enhancement with gadolinium • Soft tissue mass adjacent to vertebra ○ Low to intermediate signal intensity on all sequences ○ Minimal enhancement with gadolinium • Facet joint effusions • Variable enhancement with gadolinium administration Nuclear Medicine Findings • Bone scan ○ Positive on delayed images ○ Positive 3-phase scan in acute pseudogout attack • Best diagnostic clue ○ Linear calcific deposits in disc, ligament, hyaline cartilage, or joint capsule • Location ○ Cervical, thoracic, or lumbar spine – Calcification in ligaments, discs, facet joint capsules, hyaline cartilage ○ Sacroiliac joints, pubic symphysis ○ Peripheral skeleton: Most common in knee and triangular fibrocartilage of wrist ○ Spine involvement often seen in absence of peripheral skeleton involvement Imaging Recommendations Radiographic Findings Pseudopannus • Radiography ○ Linear disc calcifications ○ Majority of cases also show calcification in pubic symphysis &/or triangular fibrocartilage of wrist • Thickening of tectorial membrane due to degenerative changes ○ Causes soft tissue fullness around dens ○ Retroodontoid soft tissue thickness in patients with CPPD crystal deposition greater than in patients without CPPD crystal deposition • May be seen with abnormal motion secondary to more inferior cervical fusion CT Findings • Soft tissue calcifications ○ Usually linear, occasionally globular and mass-like • Ligament calcification ○ Most commonly in PLL, ligamentum flavum ○ May result in spinal stenosis • Facet joint effusions • Hyaline cartilage calcification in facet and uncovertebral joints • Erosions of vertebral endplates ○ Sharply demarcated, often corticated • Crowned dens syndrome ○ Horseshoe-shaped calcification around dens ○ Erosion of dens, often severe ○ C1-C2 instability with flexion/extension MR Findings • Calcium low signal intensity on all sequences ○ May see punctate foci ○ Often not visible because isointense to discs, ligaments • Intervertebral discs narrow and low signal intensity on all sequences ○ Indistinguishable from degenerative disc disease • Ligament thickening ○ Most commonly PLL, ligamentum flavum ○ May result in spinal stenosis • Erosions of dens, vertebral endplates • Best imaging tool ○ CT scan • Protocol advice ○ Thin-section CT with sagittal, coronal reformats Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides TERMINOLOGY DIFFERENTIAL DIAGNOSIS Degenerative Disc Disease • Disc bulges and herniations may calcify when chronic • Mild irregularity of vertebral endplate often occurs ○ Generally less severe than erosions of CPPD Rheumatoid Arthritis, Adult • Odontoid erosions, soft tissue mass may appear identical to CPPD on MR ○ Absence of calcifications distinguishes from CPPD on CT, radiographs • Spares intervertebral discs • Look for subaxial erosive changes Seronegative Spondyloarthropathy • Ligament ossifications • May appear identical to CPPD on MR Osteomyelitis, Pyogenic • Usually affects only level • High signal intensity in disc on T2WI, STIR • Phlegmon or abscess often present in spinal canal or prevertebral soft tissues • Infected areas show enhancement with gadolinium Hemodialysis Arthropathy • Endplate erosions • Calcifications due to hydroxyapatite deposition 551 Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides CPPD • Osteopenia, endplate erosions, soft tissue calcifications • Laboratory values most useful to distinguish from CPPD Ochronosis • Diffuse disc calcifications and degeneration DIAGNOSTIC CHECKLIST Gout Consider • • • • • CPPD may be present in axial skeleton without peripheral involvement • Diagnosis may be missed at surgery unless surgeon is alerted to possibility of CPPD from imaging ○ Surgical specimens usually sent to pathology in formalin ○ Formalin dissolves crystals Much less common in spine than CPPD Endplate erosions, soft tissue masses Calcification usually minimal Focal "punched-out" lesions typical Hydroxyapatite Deposition Disease • Rounded calcific deposits in soft tissues • Uncommon in spine PATHOLOGY General Features • Etiology ○ Crystal deposition of unknown etiology • Associated abnormalities ○ Multiple crystals may be present in same patient – CPPD, gout, hydroxyapatite ○ Elderly patients may have both rheumatoid arthritis and CPPD • Specimens must be sent to pathology in alcohol or saline ○ Crystals dissolve in formalin Gross Pathologic & Surgical Features • Chalky white, linear deposits of crystals • Occasionally tumoral deposits of calcification develop ○ Less common, usually due to hydroxyapatite crystals in addition to CPPD Image Interpretation Pearls • CT useful in distinguishing from rheumatoid arthritis, which does not calcify SELECTED REFERENCES Microscopic Features • Polarizing microscope shows crystals with weakly positive birefringence 10 CLINICAL ISSUES 11 Presentation 12 • Most common signs/symptoms ○ May be asymptomatic ○ Chronic back pain ○ Acute attack of pain ± fever ± radiculopathy ○ Myelopathy due to cord compression ○ Acute neck pain 13 Demographics • Age ○ Usually > 50 years old • Epidemiology ○ Atlantoaxial CPPD seen in 12.5% of population ○ Prevalence increases with age – > 60 years: 34% – > 80 years: 50% ○ ANKH (human homologue of progressive ankylosis) mutations in familial CPPD disease Treatment • Options, risks, complications 552 ○ Nonsteroidal anti-inflammatory agents ○ Some medications used to treat gout are also effective against CPPD ○ Surgical decompression, stabilization Hyperparathyroidism 14 15 Ea HK et al: Diagnosis and clinical manifestations of calcium pyrophosphate and basic calcium phosphate crystal deposition diseases Rheum Dis Clin North Am 40(2):207-29, 2014 Chang EY et al: Frequency of atlantoaxial calcium pyrophosphate dihydrate deposition at CT Radiology 269(2):519-24, 2013 Tsui FW: Genetics and mechanisms of crystal deposition in calcium pyrophosphate deposition disease Curr Rheumatol Rep 14(2):155-60, 2012 Zhang W et al: European League Against Rheumatism recommendations for calcium pyrophosphate deposition Part I: terminology and diagnosis Ann Rheum Dis 70(4):563-70, 2011 Roverano S et al: Calcification of the transverse ligament of the atlas in chondrocalcinosis J Clin Rheumatol 16(1):7-9, 2010 Fenoy AJ et al: Calcium pyrophosphate dihydrate crystal deposition in the craniovertebral junction J Neurosurg Spine 8(1):22-9, 2008 Finckh A et al: The cervical spine in calcium pyrophosphate dihydrate deposition disease A prevalent case-control study J Rheumatol 31(3):5459, 2004 Chen CF et al: Calcium pyrophosphate dihydrate crystal deposition disease in cervical radiculomyelopathy J Chin Med Assoc 66(4):256-9, 2003 Muthukumar N et al: Tumoral calcium pyrophosphate dihydrate deposition disease of the ligamentum flavum Neurosurgery 53(1):103-8; discussion 108-9, 2003 Fujishiro T et al: Pseudogout attack of the lumbar facet joint: a case report Spine 27(17):E396-8, 2002 Steinbach LS et al: Calcium pyrophosphate dihydrate crystal deposition disease: imaging perspectives Curr Probl Diagn Radiol 29(6):209-29, 2000 Berlemann U et al: Calcium pyrophosphate dihydrate deposition in degenerate lumbar discs Eur Spine J 7(1):45-9, 1998 Markiewitz AD et al: Calcium pyrophosphate dihydrate crystal deposition disease as a cause of lumbar canal stenosis Spine 21(4):506-11, 1996 Brown TR et al: Deposition of calcium pyrophosphate dihydrate crystals in the ligamentum flavum: evaluation with MR imaging and CT Radiology 178(3):871-3, 1991 el-Khoury GY et al: Massive calcium pyrophosphate crystal deposition at the craniovertebral junction AJR Am J Roentgenol 145(4):777-8, 1985 CPPD Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides (Left) Sagittal T1WI MR shows the typical pattern of CPPD involving C1-C2 articulation with a large mass ſt posterior to the odontoid process producing severe cord compression The odontoid process appears otherwise intact, and without gross erosions (Right) Sagittal T2 TSE image shows the large retroodontoid mass ſt to be relatively low in signal intensity Note the marked effacement of the thecal sac and severe cord compression (Left) Axial T2 TSE image shows a large mass with low T2 signal posterior to the odontoid process with severe cord compression ſt A small cystic focus is present within the dorsal aspect of the pseudotumorous mass due to an associated juxtaarticular cyst (Right) Axial T2WI MR demonstrates a large low T2 signal mass engulfing the retroodontoid space ſt and causing severe cord compression Note the intact cortex of the odontoid process (Left) Sagittal T1WI MR shows a mass surrounding the superior and posterior aspect of the odontoid process ſt producing cord compression The anterior aspect of C1 is poorly identified and is also involved in the pseudomass Multilevel degenerative disc disease is also present (Right) Sagittal T2 TSE T2WI MR shows the periodontoid mass to be of low signal ſt Note the severe effacement of the thecal sac and cord compression Cord integrity is compromised by multilevel subaxial spondylosis 553 Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides CPPD (Left) Sagittal bone NECT shows a large retroodontoid pseudomass effacing the ventral thecal sac ſt that contains scattered calcifications This pattern is pathognomonic of CPPD involvement of the craniovertebral junction Note the large degenerative cyst involving the odontoid (Right) Axial bone NECT shows a large retroodontoid mass that contains scattered calcifications The odontoid process is intact The presence of calcium in the soft tissue distinguishes this CPPD from RA, which does not calcify (Left) Sagittal STIR MR shows a low signal intensity mass ſt posterior to the odontoid process with moderate effacement of the ventral thecal sac The high signal is due to associated degenerative cyst involving an odontoid process (Right) Sagittal T1W C+ MR shows no enhancement ſt of the low T2 signal retroodontoid tissue, which is typical for CPPD The degenerative cyst within the odontoid process also does not enhance (Left) Sagittal T1 C+ MR shows a juxtaarticular cyst ſt associated with a CPPDinduced periodontal pseudotumor There is peripheral enhancement of the cyst and no significant enhancement from the increased periodontal pseudotumor tissue (Right) Sagittal T2WI MR demonstrates an increased signal from the juxtaarticular cyst ſt associated with the large low signal intensity pseudomass from CPPD deposition There is severe cord compression 554 CPPD Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides (Left) Sagittal bone CT shows calcifications in the facet joints at C0-1 st and C1-2 ſt CPPD involves synovial joints as well as discs and ligaments (Right) Sagittal bone CT shows multiple sites of calcification in CPPD This includes the tectorial membrane ſt, the anterior longitudinal ligament st, and multiple intervertebral discs Endplate erosions are sharply demarcated and multiple levels are involved, helping to distinguish this case from infection (Left) Sagittal T1WI MR in the same patient shows soft tissue fullness st around the dens Punctate calcifications ſt are difficult to see Multilevel endplate erosions are evident, with adjacent decreased marrow signal intensity (Right) Sagittal STIR MR in the same patient shows minimal abnormal signal intensity ſt in the vertebral bodies despite extensive CT abnormalities This is characteristic of CPPD The discs remain low signal intensity, helping to distinguish CPPD from infection (Left) Lateral radiograph shows linear disc calcification st, suggesting CPPD In contrast to these linear calcifications, the calcified disc bulges or herniations due to disc degeneration are very common and cannot be used as a sign of CPPD (Right) Sagittal STIR MR in the same patient is indistinguishable from degenerative disc disease As a general rule, CT is preferable to MR in the differential diagnosis of all forms of spine arthritis 555 Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides Gout KEY FACTS • Arthropathy secondary to urate crystal deposition TOP DIFFERENTIAL DIAGNOSES IMAGING • • • • • • • • • • • Generally involves only 1-2 levels Disc or facet joints, sacroiliac joint Most common in lumbar spine Typically have peripheral joint disease Endplate, facet erosions ○ Usually sharply demarcated ("punched out") • Preserved bone density • Tophi ○ Mass in disc space, facet joint, paravertebral, spinal canal ○ May compress cord or nerve roots ○ May contain faint, amorphous calcifications on CT ○ Low signal intensity on T1WI ○ Low to intermediate signal intensity on T2WI, STIR ○ Variable enhancement with Gd (Left) Sagittal PD/intermediate MR shows "punched out" vertebral body erosions at multiple levels There is nearly complete endplate destruction at C6-C7 Tophus is present posterior to C2 st, and there are multiple intraosseous tophi ſt (Right) Sagittal T2 MR in the same patient shows endplate destruction at C6-C7 Intraosseous tophus ſt is low signal intensity and almost indistinguishable from the surrounding marrow (Left) Axial NECT shows focal "punched out" lesion of soft tissue density in left facet ſt, not directly contiguous with the joint space Metastatic disease was primary consideration, but gout was diagnosed with biopsy (Courtesy N Farhataziz, MD.) (Right) Sagittal T2 MR shows focal erosions ſt of L5 and S1 in a patient with uncontrolled peripheral gout and flare of back pain There was minimal enhancement with gadolinium 556 ○ ± bone marrow edema adjacent to tophi TERMINOLOGY Osteomyelitis Hemodialysis arthropathy Calcium pyrophosphate deposition Neuropathic arthropathy Seronegative spondyloarthropathy Rheumatoid arthritis PATHOLOGY • Uric acid crystal deposition in soft tissues • May be secondary to chronic diseases CLINICAL ISSUES • Treatment ○ Colchicine ○ Uric acid production inhibitors (e.g., allopurinol) ○ Uricosuric medications (e.g., probenecid) Gout PATHOLOGY Definitions General Features • Arthropathy secondary to urate crystal deposition • Etiology ○ Uric acid crystal deposition in soft tissues ○ May be secondary to chronic diseases – Renal disease, myeloproliferative disorders • Specimens must be sent to pathology in alcohol; formalin dissolves crystals IMAGING General Features • Location ○ Most common in lumbar spine ○ Usually peripheral disease as well Gross Pathologic & Surgical Features Radiographic Findings • Chalky white tophi • Radiography ○ Endplate, facet erosions ○ Prevertebral soft tissue mass Presentation CLINICAL ISSUES • Endplate, facet erosions ○ Usually sharply demarcated ("punched out") • Preserved bone density • Soft tissue masses ○ May contain faint, amorphous calcifications • Most common signs/symptoms ○ Back pain, often acute and severe ○ Other signs/symptoms – Fever, neurologic symptoms • Clinical profile ○ Associated with obesity, rich diet ○ Serum uric acid may be normal at time of presentation MR Findings Demographics • Vertebral endplate destruction ○ Rounded masses may extend from disc into vertebrae ○ Discs low to intermediate signal intensity on T2WI, STIR • Facet joint erosions and tophi • Tophi ○ Mass in disc space, facet joint, paravertebral, spinal canal ○ May compress cord or nerve roots ○ Low signal intensity on T1WI ○ Low to intermediate signal intensity on T2WI, STIR ○ Variable enhancement with Gd • ± bone marrow edema adjacent to tophi • Gender ○ M:F = 20:1 – Female patients almost always postmenopausal • Epidemiology ○ Spine involvement rare CT Findings Imaging Recommendations • Best imaging tool ○ MR to show tophi, impingement on cord and nerve roots Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides TERMINOLOGY Natural History & Prognosis • Most cases respond to medical therapy Treatment • Medical ○ Nonsteroidal anti-inflammatory medications ○ Colchicine ○ Uric acid production inhibitors (e.g., allopurinol) ○ Uricosuric medications (e.g., probenecid) • Surgical decompression for neurologic symptoms DIFFERENTIAL DIAGNOSIS Osteomyelitis • Focal osteopenia • Endplate erosions • High signal intensity in discs on T2WI, STIR Hemodialysis Arthropathy SELECTED REFERENCES • Patient history is key, otherwise same appearance Calcium Pyrophosphate Deposition • Calcifications tend to be more extensive, linear Neuropathic Arthropathy • Extensive bone destruction • Bony debris, malalignment Seronegative Spondyloarthropathy McQueen FM et al: Imaging in the crystal arthropathies Rheum Dis Clin North Am 40(2):231-49, 2014 Perez-Ruiz F et al: Clinical manifestations and diagnosis of gout Rheum Dis Clin North Am 40(2):193-206, 2014 Konatalapalli RM et al: Gout in the axial skeleton J Rheumatol 36(3):609-13, 2009 Justiniano M et al: Spondyloarthritis as a presentation of gouty arthritis J Rheumatol 34(5):1157-8, 2007 Hsu CY et al: Tophaceous gout of the spine: MR imaging features Clin Radiol 57(10):919-25, 2002 Barrett K et al: Tophaceous gout of the spine mimicking epidural infection: case report and review of the literature Neurosurgery 48(5):1170-2; discussion 1172-3, 2001 King JC et al: Gouty arthropathy of the lumbar spine: a case report and review of the literature Spine 22(19):2309-12, 1997 Bonaldi VM et al: Tophaceous gout of the lumbar spine mimicking an epidural abscess: MR features AJNR Am J Neuroradiol 17(10):1949-52, 1996 • Vertebral body corner erosions • Ligament ossification, vertebral fusion Rheumatoid Arthritis • Soft tissue calcifications absent 557 Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides Longus Colli Calcific Tendinitis KEY FACTS • Deposition of calcium hydroxyapatite crystals in superior oblique tendon fibers of longus colli muscle IMAGING • Focal calcification and soft tissue swelling in prevertebral space • Almost always C1-C3 • CT ○ Retropharyngeal soft tissue swelling and calcification ○ Fluffy, amorphous calcification of longus colli ○ Elongated fluid collection extending along fascial planes ○ Decreased attenuation in longus colli muscle • MR ○ Calcifications are globular and low signal intensity on all sequences ○ Prevertebral soft tissue swelling seen, ↓ signal intensity on T1WI, ↑ on T2WI and STIR (Left) Lateral radiograph demonstrates a small density inferior to the C1 arch in the prevertebral space st There is marked prevertebral soft tissue swelling (Right) Sagittal CT reconstruction better illustrates the ossification inferior to the C1 arch ſt There is fluid in the retropharyngeal space st It is important to differentiate longus colli tendinitis from infection, which needs antibiotic treatment (Left) Axial graphic expansion shows the retropharyngeal space with fluid The longus colli muscle is a deep flexor of the neck, located anterior to the anterior longitudinal ligament The longus colli is bounded by prevertebral fascia anteriorly and vertebral column posteriorly, and is composed of superior oblique, inferior oblique, and vertical portions (Right) Axial CECT shows hypodense fluid in the retropharyngeal space ſt, anterior to the paired longus colli muscles 558 ○ Nonenhancing fluid collection with adjacent diffuse soft tissue enhancement TERMINOLOGY TOP DIFFERENTIAL DIAGNOSES • • • • Retropharyngeal abscess Cervical osteomyelitis Diffuse idiopathic skeletal hyperostosis (DISH) Calcium pyrophosphate dihydrate deposition (CPPD) disease • Gout • Tumoral calcinosis CLINICAL ISSUES • • • • • Neck pain and stiffness, odynophagia Mild leukocytosis and fever Middle-aged and older patients Resolves in 1-2 weeks Nonsteroidal anti-inflammatory medications Longus Colli Calcific Tendinitis Synonyms Calcium Pyrophosphate Dihydrate Deposition (CPPD) • Calcific prevertebral/retropharyngeal tendinitis • Calcification around dens, in discs and ligaments • May present similarly, with acute neck pain Definitions Gout • Deposition of calcium hydroxyapatite crystals in superior oblique tendon fibers of longus colli muscle • Peridiscal erosions • Soft tissue mass, faint calcifications IMAGING General Features • Best diagnostic clue ○ Focal calcification and soft tissue swelling in prevertebral space • Location ○ Almost always C1-C3 – Has been reported in lower cervical spine: C4-C5 and C5-C6 levels ○ Longus colli muscle is paired accessory neck flexor located in prevertebral space – Bounded by prevertebral fascia anteriorly and vertebral column posteriorly Tumoral Calcinosis • Calcific mass centered in large synovial joints • Complication of renal dialysis, may be familial or result of degenerated or inflamed tissue PATHOLOGY General Features • Etiology ○ Hydroxyapatite crystals deposition in longus colli muscle – May be due to local or systemic metabolic derangements, such as following ischemia, necrosis, or trauma Gross Pathologic & Surgical Features Radiographic Findings • Chalky, semiliquid calcific deposits • Radiography ○ Retropharyngeal soft tissue swelling and calcification Microscopic Features CT Findings • • • • Fluffy, amorphous calcification of longus colli Decreased attenuation in longus colli muscle Elongated fluid collection extending along fascial planes No enhancement of fluid with contrast administration MR Findings • Calcifications are globular and low signal intensity on all sequences • Prevertebral soft tissue swelling seen, ↓ signal intensity on T1WI, ↑ on T2WI and STIR • Nonenhancing fluid collection with adjacent diffuse soft tissue enhancement Imaging Recommendations • Best imaging tool ○ CT is best to detect calcification DIFFERENTIAL DIAGNOSIS • Crystals amorphous on light microscopy CLINICAL ISSUES Presentation • Most common signs/symptoms ○ Neck pain and stiffness, limited range of motion ○ Odynophagia, dysphagia ○ Mild leukocytosis, ↑ inflammatory markers and fever Demographics • Age ○ 30-60 years • Gender ○ M=F Natural History & Prognosis • Calcifications of LCT undergo spontaneous resolution ○ Margins become less well defined as calcifications are resorbed; complete resorption in ~ weeks Retropharyngeal Abscess Treatment • Rounded fluid collection on CT and MR ○ Compared to elongated fluid collection seen in longus colli tendinitis (LCT) • Rim enhancement of fluid • Short course of nonsteroidal anti-inflammatory drugs and neck stabilization may help to alleviate symptoms Cervical Osteomyelitis • Endplate erosions • Peripherally enhancing collection in perivertebral space, epidural space • Tuberculosis spondylitis can be associated with soft tissue calcification Diffuse Idiopathic Skeletal Hyperostosis (DISH) Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides TERMINOLOGY SELECTED REFERENCES Ea HK et al: Diagnosis and clinical manifestations of calcium pyrophosphate and basic calcium phosphate crystal deposition diseases Rheum Dis Clin North Am 40(2):207-29, 2014 McQueen FM et al: Imaging in the crystal arthropathies Rheum Dis Clin North Am 40(2):231-49, 2014 Boikov AS et al: Acute calcific longus colli tendinitis: an unusual location and presentation Arch Otolaryngol Head Neck Surg 138(7):676-9, 2012 Pope LE et al: Radiology quiz case Calcific prevertebral tendinitis (also known as calcific retropharyngeal tendinitis and calcific tendinitis of the longus colli) Arch Otolaryngol Head Neck Surg 137(9):953, 954, 2011 • Bone formation in anterior longitudinal ligament ○ Compared to amorphous calcification seen in LCT 559 Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides Longus Colli Calcific Tendinitis (Left) Axial CECT exhibits calcification of the longus colli tendon at the C1 level ſt There is edema in the adjacent soft tissues st (Right) Sagittal T1WI C+ MR displays enhancement of the thickened prevertebral soft tissue , indicating that underlying inflammatory soft tissue is present The area of calcification is seen as low signal ſt The inflammatory changes seen on MR resolved completely in the course of week without definitive therapy or intervention (Left) Axial T1WI C+ FS MR shows enhancement of the prevertebral soft tissues , consistent with inflammation The area of calcification is seen as low signal ſt (Right) Axial T1WI C+ FS MR demonstrates thickening and enhancement of the prevertebral muscles, particularly on the right The classic clinical profile is a middle-aged patient with sudden onset of neck pain and stiffness Acute LCT is considered relatively benign, typically resolving on its own within several weeks (Left) Sagittal CT reconstruction illustrates smooth dense calcification in the superior insertion of the left longus colli muscle Slight distension of the retropharyngeal space with fluid is also noted st The amorphous calcification lies anterior and inferior to the C1C2 joint (Right) Sagittal T2 MR in the same patient reveals the low signal of the calcific mass below the anterior atlantodental joint and marked hyperintensity of the swollen prevertebral tissues st 560 Longus Colli Calcific Tendinitis Degenerative Diseases and Arthritides: Inflammatory, Crystalline, and Miscellaneous Arthritides (Left) Axial CECT illustrates calcification in the prevertebral tissues ſt LCT typically manifests on CT as paramidline calcium hydroxyapatite crystal deposits anterior to the C1 and C2 vertebral bodies However, recent studies have brought attention to LCT existing at the C4-C5 and C5C6 levels (Right) Axial CECT displays thickening of the prevertebral muscles ſt The differential diagnosis for LCT includes retropharyngeal abscess, infectious spondylitis, trauma, or foreign body aspiration (Left) Axial CECT shows fluid in the retropharyngeal space ſt, posteriorly displacing the longus colli muscles st The fluid collection in LCT is nonenhancing and elongated This differs from a peripherally rounded fluid collection seen with retropharyngeal abscess (Right) Axial T2 MR demonstrates retropharyngeal edema st The longus colli muscles are posteriorly displaced ſt Mild hyperintensity is observed in the left longus colli muscles more than in the right (Left) Axial bone CT exhibits calcification in the prevertebral soft tissues anterior to the C1-C2 joint ſt The patient presented with acute-onset neck pain with odynophagia, neck rigidity, and headache A concurrent low-grade fever and elevated erythrocyte sedimentation rate and C-reactive protein level were present (Right) The patient was treated with antibiotics for days but without relief of symptoms Axial NECT reveals increased calcification st 561 ... Jeffrey S Ross, MD Part VI: Peripheral Nerve and Plexus SECTION 1: PLEXUS AND PERIPHERAL NERVE LESIONS 974 980 984 988 990 994 998 10 02 10 06 10 10 10 12 10 16 10 18 10 22 10 26 10 28 10 30 Normal Plexus... Jeffrey S Ross, MD 11 12 Plates and Screws Lubdha M Shah, MD and Jeffrey S Ross, MD 11 16 Cages Lubdha M Shah, MD 11 18 Interbody Fusion Devices Lubdha M Shah, MD and Jeffrey S Ross, MD 11 22 Interspinous... Segmentation Failure Diastematomyelia Partial Vertebral Duplication Incomplete Fusion, Posterior Element Neurenteric Cyst 12 8 13 2 13 4 13 6 14 0 14 4 14 8 15 2 15 4 15 6 Developmental Abnormalities Os Odontoideum