REVIEW URRENT C OPINION

Novel imaging modalities in spondyloarthritis Iris Eshed a and Kay-Geert A. Hermann b

Purpose of review The role of imaging in the diagnosis, management, and follow-up of patients with spondyloarthritis (SpA) has become dramatically more important with the introduction of new therapies such as tumor necrosis factor-a inhibitors. In the current review, contemporary perspectives on developments and advancements in the field of SpA imaging along with several novel imaging techniques for the diagnosis and follow-up of SpA will be discussed. Recent findings No new imaging modalities have been introduced in the last decade. However, new advances and improvements within the known modalities are constantly being presented and tested. Such advances include the use of contrast material and sonoelastography in the ultrasound evaluation of enthesitis, hybridization of PET imaging with computed tomography and MRI for the evaluation of the axial and peripheral skeleton, as well as advances within MRI such as whole-body MRI and diffusion-weighted sequences. These techniques will be presented and their advantages and disadvantages will be critically discussed. Summary Promising new techniques in the field of SpA imaging are constantly emerging. The benefits and advantages of the presented techniques over the known ones need further validation. Keywords enthesitis, imaging, sacroiliitis, spondyloarthritis

INTRODUCTION The role of imaging in the diagnosis, management, and follow-up of patients with spondyloarthritis (SpA) has become dramatically more important with the introduction of new therapies such as tumor necrosis factor-a inhibitors. This is especially true with respect to axial manifestations of SpA that are clinically difficult to evaluate. With effective therapy now also available for early SpA, an accurate diagnosis is crucial. As a result, there is an increasing clinical demand for reliable and fast tests that can distinguish between patients that are most appropriate for biological therapy, and provide imaging insight on the immediate and long-term clinical response. The optimal imaging modality should facilitate early, sensitive, and specific diagnosis, would ideally cover multiple disease target sites, would not involve ionizing radiation, and, of course, is expected to be quick and relatively inexpensive. The main imaging modalities available are Conventional radiography, computed tomography (CT), ultrasound, nuclearmedicine including PET,and MRI. MRI is currently considered the most sensitive and accurate diagnostic tool for the evaluation of

early SpA by which the two main components of the disease, the active inflammatory and the structural damage, can be reliably assessed. In the current review, contemporary perspectives on developments and advancements in the field of SpA imaging along with several novel imaging techniques for the diagnosis and follow-up of SpA will be discussed.

CONVENTIONAL RADIOGRAPHY Conventional radiography has been used for decades for the diagnosis of the sacroiliac joints (SIJs) and spinal involvement of SpA patients with the use of the modified New York criteria to classify sacroiliitis [1]. Indeed, despite the increasing role of MRI in a

Department of Diagnostic Imaging, Sheba Medical Center, Affiliated to the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel and b Department of Radiology, Charite´ Medical School, Berlin, Germany Correspondence to Iris Eshed, MD, Department of Diagnostic Imaging, Sheba Medical Center,Tel Hashomer 52621, Israel. Tel: +972 3 5302498; fax: +972 3 5302220; e-mail: [email protected] Curr Opin Rheumatol 2015, 27:333–342 DOI:10.1097/BOR.0000000000000186

1040-8711 Copyright ß 2015 Wolters Kluwer Health, Inc. All rights reserved.

www.co-rheumatology.com

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Spondyloarthropathies

KEY POINTS  Ultrasonography and MRI are important key imaging modalities for early diagnosis of SpA.  Functional imaging by PET may further broaden our knowledge of the pathogenesis of SpA, but because of radiation exposure routine clinical use may be limited.  Recent advancement in SpA imaging may have potential in early diagnosis and better understanding of SpA; however, further testing and validation are still warranted.

diagnosing sacroiliitis, the new criteria for SpA classification of the Assessment of SpondyloArthritis international Society (ASAS) still give an equal weight for both conventional radiography and MRI in the imaging arm for sacroiliitis classification [2].

(a)

As conventional radiography is considered superior to MRI in the evaluation of spinal syndesmophytes [3], follow-up of patients with axial involvement is recommended to be performed once every 2 years [4]. Thus, over their lifetime, SpA patients are repeatedly exposed to X-rays with an increased lifetime ionizing radiation exposure. EOS is a technique offering reduced X-ray ionizing radiation exposure introduced recently [5 ,6]. The EOS, a biplane X-ray imaging system, uses two perpendicular X-ray beams collimated in two horizontal, fan-shaped beams and two specific detectors. This allows simultaneous whole-spine frontal and lateral radiographs (Fig. 1) to be carried out with a reported five to six-fold reduced radiation dose compared with conventional radiography [6]. Molto et al. [5 ] evaluated intermodality (conventional radiography vs. EOS) agreement in scoring of the spine [modified stoke ankylosing spondylitis (AS) spine &

&

(b)

FIGURE 1. Biplanar EOS1 radiographs of the whole spine in the anteroposterior and lateral views of a 53-year-old male with spondyloarthritis. Bilateral grade 3 sacroiliitis can be appreciated as well as a bridging syndesmophyte at the L5-S1 and L1-2 levels. Reproduced by courtesy of Anna Molto. 334

www.co-rheumatology.com

Volume 27  Number 4  July 2015

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Novel imaging modalities in spondyloarthritis Eshed and Hermann

score] and SIJ (modified New York criteria) of SpA patients and controls. Agreement for spinal scoring was very good (K > 0.9) but only moderate for SIJ scoring (K ¼ 0.5). The authors conclude that this reduced ionizing radiation EOS technology could replace conventional radiography in follow-up for spinal structural, damage and progression of SpA patients, but, not for SIJ evaluation.

ULTRASOUND Ultrasound, a radiation free, cost-efficient, and potentially dynamic imaging modality, is widely used for the evaluation of the peripheral joints and entheses of SpA patients. In enthesitis, a common pathology in SpA, increased vascularization occurs at the bone entheses junction. Power Doppler ultrasound may detect this increased vascularization; however, especially in the smaller joints, it is sometimes difficult to appreciate vascularization of the affected entheses.

Contrast-enhanced ultrasound Following the advent of new microbubble contrast agents in ultrasound, an ultrasound imaging technique was developed to increase the sensitivity of the Doppler examination: pulse-inversion harmonic imaging [7]. This contrast-enhanced ultrasound (CEUS) technique exploits the properties of microbubble contrast material, which are based on the generation of harmonics from nonlinear

(a)

oscillation of bubbles. Using this technique, gasfilled microbubbles injected intravenously accumulate in a hypervascularized area and cause reflection of the sound waves with increased echogenicity at the inflamed tissue. Ultrasound contrast agents are now routinely used in research and daily practice in oncology and have also been applied to the rheumatology field for enhancing the vascularization signal of synovitis (Fig. 2). CEUS of the enthesis in patients with SpA was shown to confirm the presence of peri-entheseal hypervascularization and improved the detection of enthesitis by confirming all doubtful enthesitis signals and the absence of enthesis vascularization [8]. Opposite to contrast injection as applied in CT or MRI examinations, due to the short half-life of the ultrasound contrast agents, only one joint or enthesis evaluation per contrast injection is feasible by ultrasound to measure early enhancement rate, time to peak, and other parameters. However, more than one location may be scanned during the late phase of CEUS. This shortcoming of CEUS eliminates one of the great advantages of ultrasound examination, its flexibility in the number of joints and enthesis evaluated, and limits its use in everyday evaluation of SpA patients.

Sonoelastography Another relatively new ultrasound-based imaging technique is sonoelastography, a technique that provides information on the elastic properties and

(b)

(c)

FIGURE 2. Contrast-enhanced ultrasound of the talonavicular joint in a 54-year-old man with psoriatic arthritis showing (a) marked synovial hypertrophy and (b) marked enhancement of microbubble contrast agent (raw data-based contrast harmonic imaging). (c) Enhancement can be dynamically visualized and objective parameters such as rate of early enhancement and peak enhancement may be calculated. Reproduced by courtesy of Thomas Fischer. 1040-8711 Copyright ß 2015 Wolters Kluwer Health, Inc. All rights reserved.

www.co-rheumatology.com

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

335

Spondyloarthropathies

stiffness of various tissues and lesions. Depending on their elastic properties, tissues deform and move away from the ultrasound transducer when pressure is applied. The amount of displacement from the ultrasound transducer differs between tissues and lesions and between healthy and inflamed tissues. Sonoelastography is currently being used mainly in the diagnosis and evaluation of liver diseases, and mass lesions of the thyroid and breast. Several preliminary studies evaluated the elastographic appearance of healthy and pathologic Achilles tendon and plantar fascia as well as joints (Fig. 3). Although a majority of these studies report homogenous normal tendon structure compared with an inhomogeneity of the pathologic tendons, results are contradictory with regard to the elasticity of the pathologic tendons in which some of the studies report softening of the pathologic tendons whereas others report their stiffening [9]. A recent study [10] compared the elastographic appearance of the Achilles tendon in AS patients compared with healthy controls. It was shown that the distal part of the Achilles tendon was most commonly affected in AS patients compared with healthy individuals in which the middle third of the Achilles tendon was more commonly affected. In addition, they have shown that softening detected by sonoelastography in the distal third was associated with enthesopathy findings such as calcaneal bone erosions and tendinous enlargement. Owing to the wide variety of techniques and processing algorithms currently available for producing elastographic images, findings may be highly specific and dependent on the technique used. It seems that more studies are warranted before this technique could be widely used for enthesitis evaluation of SpA patients.

(a)

HYBRID PET-COMPUTED TOMOGRAPHY/ MRI PET provides molecular data as opposed to anatomic and functional data obtained by ultrasound and MRI. The use of specific tracers targeted to binding sites with essentially visualization of pathophysiology makes PET a sensitive imaging modality for functional tissue changes potentially suitable for early detection of inflammatory processes. The use of hybrid techniques combines the unique molecular data properties of PET and anatomical imaging sites seen on CT or MRI as a reference. Several tracers with a potential role in SpA imaging have been tested using PET-CT and PET-MRI in a small AS cohort [11 ]. These include [18F]fluorodeoxyglucose targeted for synovial tissue, [11C](R)PK11195 targeted for macrophage uptake, and [18F]fluoride targeting active bone. Only [18F]fluoride uptake was seen in these patients with high correlation to structural bony changes in the uptake areas. During bone remodeling or tissue repair, fluoride is incorporated into the skeleton at sites of active osteoblastic bone synthesis and thus [18F]fluoride uptake represents direct in-vivo molecular imaging of bone synthetic activity. Two studies [11 ,12 ] evaluated the spine of AS patients and correlated [18F]fluoride uptake by PET with CT structural changes as well as MRI bone marrow edema or fatty corners. [18F]fluoride uptake was mainly seen in sites with fat deposition but not bone marrow edema (Fig. 4) and on areas with syndesmophytes on CT. That is, there is a role for PET in the detection of osteoblastic activity in areas where no inflammatory signal is detected suggesting PET may be of interest for the understanding and prediction of structural disease progression in axial SpA [12 ]. The role of [18F]fluoride PET was also evaluated in the peripheral joints of SpA patients [13 ]. The authors found similar uptake patterns in &&

&&

&

&

&

(b)

FIGURE 3. Axial MRI image of the same patient as in Figure 2 showing (a) marked osteitis as well as synovitis emerging from the middle subtalar joint. Strain elastography in the decompression phase reveals (b) hypertrophic synovium as well as joint effusion. Note the stiff property of water (blue) compared with the softness of the synovial tissue (yellow and red). Reproduced by courtesy of Thomas Fischer. 336

www.co-rheumatology.com

Volume 27  Number 4  July 2015

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Novel imaging modalities in spondyloarthritis Eshed and Hermann

(a)

(b)

(c)

(d)

FIGURE 4. [18F]fluoride PET-MRI of the sacroiliac joints of a patient with spondyloarthritis. In the semicoronal (a) hybrid PET-MRI, (b) PET, (c) T1, and (d) STIR images, a tracer uptake can be seen around an erosive and irregular left ilium with fat deposition but almost no bone marrow edema around it. Reproduced by courtesy of Xenofon Baraliakos. STIR, short TI inversion recovery.

the distal phalanges between patients with psoriatic arthritis (Fig. 5) and patients with osteoarthritis. This pattern was not seen in healthy controls. Thus, it was suggested that PET may have a role in enthesitis evaluation. None of the studies evaluating the role of hybrid PET techniques has proved an advantage or an additive role for PET over MRI. In addition, one needs to take into account that PET on its own is involved with ionizing radiation that could be quite substantial (up to 25 milisievert) [14]. If added to whole-body CT, the amount of radiation exposure increases even more, and exposes the young SpA patients into unnecessary radiation.

MRI MRI is currently considered the best imaging modality to identify early, non-radiographic inflammatory changes in the spine and SIJs of patients with SpA. Several techniques and sequences used in other fields such as neuroimaging are now being tested for potential use in SpA imaging field. FIGURE 5. High-resolution right-hand [18F]fluoride PET of a 71-year-old female with psoriasis affecting the skin, scalp, and nails, and 20-month history of joint pain. Diffuse uptake is seen in the third distal interphalangeal joint, in which psoriatic nail changes were also present (not shown). Reproduced by courtesy of Ai Lyn Tan and Dennis McGonagle.

Whole-body MRI One such technique is whole-body MRI (wbMRI). Multichannel technology with the concurrent use of several coils allows the scanning of the entire spine and the SIJs within 30–40 min without patient

1040-8711 Copyright ß 2015 Wolters Kluwer Health, Inc. All rights reserved.

www.co-rheumatology.com

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

337

Spondyloarthropathies

repositioning. WbMRI allows the visualization of inflammatory changes with spatial resolution similar to standard magnetic resonance examinations [15]. T1 and short time STIR¼Short Time Inversion Recovery inversion recovery (STIR) sequences can be performed in coronal orientation covering the entire spine, shoulders and arms, anterior chest wall, and pelvis including the SIJ and the lower extremities (designated true wbMRI, Fig. 6) or in sagittal orientation for the entire spine with additional semicoronal orientation for the SIJ (designated whole-spine MRI, Fig. 7). WbMRI allows simultaneous assessment of peripheral and axial joints, is sensitive for the detection and localization of inflammatory lesions in multiple sites, and is mainly advantageous for the evaluation of enthesitis [15,16 ]. Evaluation of inflammatory lesions was shown to be reliable and reproducible mainly for the axial spine and has lower reproducibility in the smaller most peripheral joints such as proximal and distal interphalangial joints [16 ]. The use of wbMRI or whole-spine MRI as a ‘one-stop shop’ screening tool can be useful in the initial evaluation &

&

(a)

(b)

of disease load and activity as well as for patients’ follow-up and in clinical trials [17,18,19 ]. &

Diffusion-weighted MRI Diffusion-weighted MRI is based on the tissuedependent signal attenuation caused by incoherent thermal motion of water molecules. Mobility of water molecules is driven by thermal agitation and is highly dependent on its cellular environment. Water molecules have a random Brownian motion within the voxel. The diffusion of water inside a voxel of tissue is hindered primarily by cell membrane boundaries. The greater the mean free path of water molecules, the greater the signal loss or, in other words, the greater the cellularity, the greater the diffusion restriction. Thus, water molecule diffusion patterns can reveal microscopic details about tissue architecture, either normal or in a diseased state. Using diffusion MRI technology, extracellular water has low DWI signal whereas intracellular water has high DWI signal. Inflammatory lesions are expected to have a changed intra/extracellular ratio and thus

(c)

(d)

FIGURE 6. A whole body MRI of a patient with spondyloarthritis demonstrating acute and structural inflammatory lesions. Coronal STIR (a and b) whole body images demonstrate bilateral bone marrow edema in the sterno-clavicular joints, synovitis in the right knee and right sided scaroiliitis (arrows). Semicoronal T1 (c) and STIR (d) images in which multiple erosions and limited bone marrow edema (arrowheads) as well as fat conversion are seen in the right sacroiliac joint. Reproduced by courtesy of Mikkel Ostergaard. 338

www.co-rheumatology.com

Volume 27  Number 4  July 2015

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Novel imaging modalities in spondyloarthritis Eshed and Hermann

(a)

(b)

(c)

(d)

FIGURE 7. Whole-spine MRI of a patient with spondyloarthritis demonstrating acute and some structural chronic lesions corresponding to SpA. (a) Sagittal T1 and (b) STIR images of the spine demonstrate vertebral corner fat replacement (white arrows) and active inflammatory lesions (black arrows). (c) Semicoronal T1 and (d) STIR images in which bilateral bone marrow edema is seen in the iliac and sacral sides of the sacroiliac joints. SpA, spondyloarthritis; STIR, short TI inversion recovery. Reproduced by courtesy of Mikkel Ostergaard.

(a)

(b)

(c)

(d)

(e)

(f)

FIGURE 8. (a, d) Semicoronal T1, (b, e) STIR, and (c, f) DWI images of the sacroiliac joint in two patients. In the first patient (a–c), extensive bilateral sacroiliitis with bone marrow edema, synovitis, and capsulitis can be seen with corresponding high signal intensity on DWI. The second patient (d–f) has very subtle bone marrow edema on the iliac side of the left sacroiliac joint with the corresponding high signal intensity seen on the DWI sequence verifying the presence of that subtle bone marrow edema (arrow on e and f). Reproduced by courtesy of Iwona Sudoł-Szopin´ska. DWI, diffusion-weighted imaging; STIR, short TI inversion recovery. 1040-8711 Copyright ß 2015 Wolters Kluwer Health, Inc. All rights reserved.

www.co-rheumatology.com

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

339

Spondyloarthropathies

(a)

(b)

(c)

(d)

FIGURE 9. 44-year-old woman with ankylosing spondylitis. (a) Conventional X-ray shows bilateral grade 3 sacroiliitis. (b) Low dose computed tomography reveals the the full extent of erosive destruction of the joint surfaces. (c) Semicoronal T1-weighted image depicts bone sclerosis and irregular joint surfaces. Some single erosions may be distinguished in the left joint. (d) 3D gradient echo MRI sequence (VIBE - volume interpolated breath hold examination) depicts the articular cartilage hyperintense (bright) with surrounding bone hypointense (dark), thus enabling detailed visualization of bone erosions similar to CT. Images courtesy of Dr. Torsten Diekhoff.

Table 1. New imaging techniques for spondyloarthritis: advantages, disadvantages, and potential future use Technique

Modality

EOS

Target organ

Potential advantage

Disadvantage

Potential use

Conventional Axial spine radiography

Reduced radiation

Reduced reliability for SIJ evaluation

Patients’ follow-up

CEUS

US

Entheses, tendons, and joints

Detection of hypervascularized tissues

Short half-life; one enthesis evaluation per injection; not yet validated

Earlier enthesitis detection

Sonoelastography

US

Tendons, ligaments, and entheses

Increased sensitivity for abnormal tendon/ ligament

Not yet validated

Earlier detection of tendinitis and enthesitis

Hybrid PET-CT/ MRI

PET/CT/MRI

Axial, appendicular skeleton, and entheses

Combination of functional and anatomical data

Increased radiation exposure; not yet validated

Earlier detection of bone formation/entheseal inflammation; research

Whole-body/ spine MRI

MRI

Axial and appendicular skeleton

‘One-stop shop’ evaluation of spine, joints, and entheses

Reduced resolution; relatively long examination time

Estimate total disease load and activity; patients’ follow-up

DWI

MRI

Sacroiliac joints

Sensitive detection of bone inflammation

Reduced resolution; not yet validated

May replace contrast material

High-resolution MRI MRI

Sacroiliac joints

Sensitive detection of bone erosions

Needs further validation

Early and accurate detection of sacroiliitis

CEUS, contrast-enhanced ultrasound; CT, computed tomography; DWI, diffusion-weighted imaging.

340

www.co-rheumatology.com

Volume 27  Number 4  July 2015

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Novel imaging modalities in spondyloarthritis Eshed and Hermann

an altered signal. DWI imaging would be useful if it offered higher sensitivity compared with conventional MRI STIR images in the detection of early inflammatory lesions (Fig. 8). One such potential benefit was shown when diffusion values of spinal inflammatory lesions were significantly higher compared with mechanical induced Modic I type lesions offering a potential added value for DWI in differentiating between the two. SIJ diffusion contrast was shown to change after treatment and differ between SpA patients compared with patients with mechanical LBP [20–22]; however, this was also seen in conventional MRI. A recent study [23] showed diffusion contrast alteration in SpA patients with no apparent active inflammation in their SIJ. The role of DWI imaging in early diagnosis of sacroiliitis needs further verification and validation.

High-resolution MRI Although several methods for evaluation of MRI of the SIJs did evolve over the past decade, the imaging technique itself has not changed tremendously. Still, conventional T1-weighted sequences along with STIR images are regarded as the method of choice to depict active and chronic sacroiliitis. CT is regarded the standard of reference to depict structural lesions, that is, erosions. On the contrary, conventional X-rays are still used for the classification of axial SpA, mainly due to cost considerations and the broad basis of scientific data. Gradient echo sequences with fat saturation produce magnetic resonance images with hyperintense depiction of cartilage whereas surrounding bone is depicted hypointense, thus allowing detailed analysis of erosions. Depending on slice thickness, erosions as small as 0.8 mm may be detected by MRI (Fig. 9), a resolution that could formerly be achieved only by CT scanning. Preliminary data show an increased detection rate for erosions by high-resolution MRI [24 ]. &

CONCLUSION Promising new techniques in the field of SpA imaging have been portrayed in the current review. A summary of the presented techniques along with their advantages, disadvantages, and their potential future use is presented in Table 1. The benefits of these techniques over the known validated ones and their contribution to early SpA diagnosis as well as better understanding of pathogenesis of SpA need further validation. Acknowledgements The authors are very grateful for the images generously contributed to this manuscript by Xenofon Baraliakos,

Torsten Diekhoff, Thomas Fischer, Dennis McGonagle, Anna Molto, Mikkel Ostergaard, Iwona Sudoł-Szopin´ska, and Ai Lyn Tan. Financial support and sponsorship None. Conflicts of interest There are no conflicts of interest.

REFERENCES AND RECOMMENDED READING Papers of particular interest, published within the annual period of review, have been highlighted as: & of special interest && of outstanding interest 1. van der Linden S, Valkenburg HA, Cats A. Evaluation of diagnostic criteria for ankylosing spondylitis. A proposal for modification of the New York criteria. Arthritis Rheum 1984; 27:361–368. 2. Rudwaleit M, Landewe R, van der Heijde D, et al. The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part I): classification of paper patients by expert opinion including uncertainty appraisal. Ann Rheum Dis 2009; 68:770–776. 3. Weber U, Maksymowych WP. Advances and challenges in spondyloarthritis imaging for diagnosis and assessment of disease. Curr Rheumatol Rep 2013; 15:345. 4. Zochling J, van der Heijde D, Burgos-Vargas R, et al. ASAS/EULAR recommendations for the management of ankylosing spondylitis. Ann Rheum Dis 2006; 65:442–452. 5. Molto A, Freire V, Feydy A, et al. Assessing structural changes in axial & spondyloarthritis using a low-dose biplanar imaging system. Rheumatology (Oxford) 2014; 53:1669–1675. EOS system in this study was shown to be reliable for sacroiliac evaluation but not as reliable for the evaluation of the spine of SpA patients. 6. Wade R, Yang H, McKenna C, et al. A systematic review of the clinical effectiveness of EOS 2D/3D X-ray imaging system. Eur Spine J 2013; 22:296–304. 7. Kim AY, Choi BI, Kim TK, et al. Comparison of contrast-enhanced fundamental imaging, second-harmonic imaging, and pulse-inversion harmonic imaging. Invest Radiol 2001; 36:582–588. 8. Mouterde G, Aegerter P, Correas JM, et al. Value of contrast-enhanced ultrasonography for the detection and quantification of enthesitis vascularization in patients with spondyloarthritis. Arthritis Care Res (Hoboken) 2014; 66:131–138. 9. Drakonaki EE, Allen GM, Wilson DJ. Ultrasound elastography for musculoskeletal applications. Br J Radiol 2012; 85:1435–1445. 10. Turan A, Tufan A, Mercan R, et al. Real-time sonoelastography of Achilles tendon in patients with ankylosing spondylitis. Skeletal Radiol 2013; 42:1113–1118. 11. Bruijnen ST, van der Weijden MA, Klein JP, et al. Bone formation rather than && inflammation reflects ankylosing spondylitis activity on PET-CT: a pilot study. Arthritis Res Ther 2012; 14:R71. This is the first time the [18F]fluoride tracer was shown to have correlation with structural bony changes in SpA patients. 12. Baraliakos X, Buchbender B, Ostendorf B, et al. Conventional magnetic & resonance imaging (MR), hybrid 18f-Fluoride positron emission tomography MRI (18f-F- PET/MRI) and computer tomography of the spine: a detailed description of pathologic signals in patients with active ankylosing spondylitis. Ann Rheum Dis 2014; 73 (Suppl 2):79. Hybridization of PET and MRI in this study verified correlation between [18F]fluoride uptake in postinflammatory fat deposition locations. 13. Tan AL, Tanner SF, Waller ML, et al. High-resolution [18F]fluoride & positron emission tomography of the distal interphalangeal joint in psoriatic arthritis: a bone-enthesis-nail complex. Rheumatology (Oxford) 2013; 52:898–904. High-resolution [18F]fluoride PET was shown to have different uptake between psoriatic arthritis and osteoarthritis patients compared with normal controls. 14. Brix G, Lechel U, Glatting G, et al. Radiation exposure of patients undergoing whole-body dual-modality 18F-FDG PET/CT examinations. J Nucl Med 2005; 46:608–613. 15. Poggenborg RP, Eshed I, Ostergaard M, et al. Enthesitis in patients with psoriatic arthritis, axial spondyloarthritis and healthy subjects assessed by ‘head-to-toe’ whole-body MRI and clinical examination. Ann Rheum Dis 2015; 74:823–829.

1040-8711 Copyright ß 2015 Wolters Kluwer Health, Inc. All rights reserved.

www.co-rheumatology.com

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

341

Spondyloarthropathies 16. Poggenborg RP, Pedersen SJ, Eshed I, et al. Head-to-toe whole-body MRI in psoriatic arthritis, axial spondyloarthritis and healthy subjects: first steps towards global inflammation and damage scores of peripheral and axial joints. Rheumatology (Oxford) 2014. [Epub ahead of print] WbMRI is suggested here as one-stop shop imaging modality of both the axial and peripheral spine for the evaluation of global inflammation and structural changes in SpA patients. 17. Song IH, Hermann KG, Haibel H, et al. Prevention of new osteitis on magnetic resonance imaging in patients with early axial spondyloarthritis during 3 years of continuous treatment with etanercept: data of the ESTHER trial. Rheumatology (Oxford) 2015; 54:257–261. 18. Karpitschka M, Godau-Kellner P, Kellner H, et al. Assessment of therapeutic response in ankylosing spondylitis patients undergoing antitumour necrosis factor therapy by whole-body magnetic resonance imaging. Eur Radiol 2014; 23:1773–1784. 19. Althoff CE, Sieper J, Song IH, et al. Active inflammation and structural change & in early active axial spondyloarthritis as detected by whole-body MRI. Ann Rheum Dis 2013; 72:967–973. This is the first article to suggest a role for wbMRI for evaluation of active inflammation and structural changes. &

342

www.co-rheumatology.com

20. Gaspersic N, Sersa I, Jevtic V, et al. Monitoring ankylosing spondylitis therapy by dynamic contrast-enhanced and diffusionweighted magnetic resonance imaging. Skeletal Radiol 2008; 37:123– 131. 21. Bozgeyik Z, Ozgocmen S, Kocakoc E. Role of diffusion-weighted MRI in the detection of early active sacroiliitis. AJR Am J Roentgenol 2008; 191:980– 986. 22. Sanal HT, Yilmaz S, Simsek I, et al. Apparent diffusion coefficients of sacroiliitis in patients with established ankylosing spondylitis. Clin Imaging 2013; 37:734–739. 23. Gezmis E, Donmez FY, Agildere M. Diagnosis of early sacroiliitis in seronegative spondyloarthropathies by DWI and correlation of clinical and laboratory findings with ADC values. Eur J Radiol 2013; 82:2316– 2321. 24. Diekhoff T, Greese J, Krohn M, et al. Erosion detection on the SI-joints – a & comparison between X-ray, low dose CT and MRI including high resolution sequences. Ann Rheum Dis 2014; 73:79–80. The first major study that methodically evaluates the diagnostic accuracy of MRI for the detection of erosions in comparison to radiograph and CT.

Volume 27  Number 4  July 2015

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Novel imaging modalities in spondyloarthritis.

The role of imaging in the diagnosis, management, and follow-up of patients with spondyloarthritis (SpA) has become dramatically more important with t...
709KB Sizes 0 Downloads 13 Views