close

Вход

Забыли?

вход по аккаунту

?

Spondyloarthritis research Consortium of Canada magnetic resonance imaging index for assessment of sacroiliac joint inflammation in ankylosing spondylitis.

код для вставкиСкачать
Arthritis & Rheumatism (Arthritis Care & Research)
Vol. 53, No. 5, October 15, 2005, pp 703–709
DOI 10.1002/art.21445
© 2005, American College of Rheumatology
ORIGINAL ARTICLE
Spondyloarthritis Research Consortium of Canada
Magnetic Resonance Imaging Index For
Assessment of Sacroiliac Joint Inflammation in
Ankylosing Spondylitis
WALTER P. MAKSYMOWYCH,1 ROBERT D. INMAN,2 DAVID SALONEN,2 SUHKVINDER S. DHILLON,1
MARTIN WILLIAMS,1 MILLICENT STONE,2 BARBARA CONNER-SPADY,1 JANICE PALSAT,1 AND
ROBERT G. W. LAMBERT1
Objective. To develop a feasible magnetic resonance imaging (MRI)– based scoring system for sacroiliac joint inflammation in patients with ankylosing spondylitis (AS) that requires minimal scan time, does not require contrast enhancement, evaluates lesions separately at each articular surface, and limits the number of sacroiliac images that are scored.
Methods. A scoring method based on the assessment of increased signal denoting bone marrow edema on T2-weighted
STIR sequences was used. MRI films were assessed blindly in random order at 2 sites by multiple readers. Intra- and
interreader reliability was assessed by intraclass correlation coefficient (ICC); the 24-week response of patients with AS
randomized to placebo:infliximab (3:8) was assessed by effect size and standardized response mean. The reliability and
responsiveness of the scoring method were compared for STIR and gadolinium diethylenetriaminepentaacetic (GdDTPA)– enhanced MRI sequences.
Results. We scanned 11 patients with AS with clinically active disease and 11 additional patients randomized to the trial
of infliximab therapy. ICC for total sacroiliac joint STIR score ranged from 0.90 to 0.98 (P < 0.00001) and interobserver
ICC for combined readers from the 2 sites was 0.84 (P < 0.0001). ICC for change scores was lower for STIR (ICC 0.53) than
for Gd-DTPA– enhanced sequences (ICC 0.79). Responsiveness was poor, although fusion was evident in one-third of
patients who received treatment (placebo:infliximab) and inflammation scores were low.
Conclusion. The Spondyloarthritis Research Consortium of Canada MRI index is a feasible and reproducible index for
measuring sacroiliac joint inflammation in patients with AS.
KEY WORDS. Magnetic resonance imaging; Ankylosing spondylitis; Validation.
INTRODUCTION
Ankylosing spondylitis (AS) is a relatively common form
of arthritis that, until recently, has had limited therapeutic
Dr. Maksymowych is a Senior Scholar of the Alberta
Heritage Foundation for Medical Research.
1
Walter P. Maksymowych, FRCP(C), Suhkvinder S. Dhillon, FRCR(UK), Martin Williams, FRCR(UK), Barbara Conner-Spady, PhD, Janice Palsat, RTMR, Robert G. W. Lambert, FRCP(C): University of Alberta, Edmonton, Alberta,
Canada; 2Robert D. Inman, FRCP(C), David Salonen,
FRCP(C), Millicent Stone, MRCP(UK): University of Toronto, Ontario, Toronto, Canada.
Address correspondence to Walter P. Maksymowych,
FRCP(C), 562 Heritage Medical Research Building, University of Alberta, Edmonton, Alberta, Canada T6G 2S2. Email: walter.maksymowych@ualberta.ca.
Submitted for publication August 26, 2004; accepted in
revised form January 24, 2005.
options. Although recent advances in the development,
validation, and standardization of clinical outcome instruments have greatly facilitated the development of new
therapeutics for this disease, these self-administered instruments are subjective and primarily assess symptoms
(1,2). There are currently no established validated instruments that provide objective measures of disease activity.
Acute phase reactants are elevated in only 40% of patients
with disease confined to the axial spine and correlate
poorly with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (3,4). Radiologic instruments such
as plain radiography and computed tomography assess
structural damage, although nuclear isotopic imaging
lacks resolution and specificity (5,6).
Magnetic resonance imaging (MRI) is a relatively new
imaging tool that allows detailed visualization of soft tissues. It was first introduced as a tool in the evaluation of
patients with AS a decade ago (7) and since then its use
703
704
has further advanced our understanding of the pathogenesis of disease. In particular, the use of fat suppression
techniques (allowing visualization of lesions within bone
marrow that may be obscured by marrow fat on other MRI
sequences) has shown that one of the earliest demonstrable lesions in the sacroiliac joints of patients with inflammatory back pain is subchondral bone marrow edema
(BME) (8,9). Prospective followup of these patients has
also shown that these lesions identified by MRI may have
predictive validity for the development of the typical plain
radiographic features of sacroiliitis (10,11).
A further advance has been the use of gadolinium contrast enhancement in MRI, which is used to delineate
regions of increased vascularity and altered capillary permeability typically associated with BME and inflammation. Dynamic imaging constitutes a further refinement
whereby the rate and maximal uptake of gadolinium can
be assessed by consecutive scans of regions of interest
within the joint that are defined subjectively. This has led
some investigators to develop grading schemes for assessing the degree of inflammation evident on MRI of the
sacroiliac joint (12). A significant drawback of scoring
lesions by dynamic MRI, however, has been the unreliability of defining the region of interest on successive scans.
The construct validity of the sacroiliac joint lesion observed on MRI has been addressed by demonstrating correlations between the grade of inflammation on MRI and
both the severity of patient symptoms and the response to
intraarticular steroid injections (13). The MRI grade of
inflammation has also been shown to correlate with the
histopathologic grade of inflammation observed in sacroiliac joint biopsies (14).
These developments have led some investigators to propose that MRI be used to provide an objective measure of
disease activity in AS. To date, there have been no detailed
reports describing the validation of a scoring system for
inflammation of the sacroiliac joints. The Spondyloarthritis Research Consortium of Canada (SPARCC) has begun a
systematic program of developing feasible and responsive
MRI-based outcome tools for scoring inflammation and
structural damage in both spine and sacroiliac joints. We
describe the development and validation of a simplified
scoring system for the assessment of disease activity in
2-dimensional planes in the sacroiliac joints that has been
validated by investigators at 2 Canadian sites, the Universities of Alberta and Toronto.
PATIENTS AND METHODS
Patients and study protocol. We studied 2 cohorts of
patients with AS as defined by the modified New York
criteria (15). Cohort A was a cross-sectional cohort of 11
patients with AS (8 men, mean age 38.9 years [range
29 – 66 years], mean disease duration 12.7 years [range
2–36 years], mean BASDAI score 5.9) who attended the
outpatient clinic in the rheumatic disease unit at the University of Alberta. All patients were receiving nonsteroidal
antiinflammatory drug therapy and were considered candidates for anti–tumor necrosis factor ␣ therapy.
Cohort B was a group of 11 patients who had severe,
Maksymowych et al
active disease as defined by a BASDAI score ⱖ4 and who
had been randomized to receive either placebo or infliximab (3:8) in a 24-week, double-blind, placebo-controlled
trial. These patients were recruited at the University of
Alberta and comprised 8 men and 3 women (mean age 45.1
years [range 36 –59 years], mean disease duration 19.2
years [range 11–38], mean BASDAI score at baseline 6.2).
These patients were part of a larger multicenter international study of 275 patients, although MRI of the sacroiliac
joints was not included in the study protocol. Consequently, images of the sacroiliac joints were only available
at the University of Alberta site.
Cohort A underwent MRI at a single time point, whereas
Cohort B underwent MRI at baseline and 24 weeks after
randomization. Either placebo or infliximab 5mg/kg was
administered intravenously at baseline, 2 weeks, 6 weeks,
and every 6 weeks thereafter. The study was approved by
the University of Alberta ethics committee.
Magnetic resonance imaging. MRI was performed with
1.5 Tesla (Siemens, Erlangen, Germany) systems using appropriate surface coils. Sequences were acquired in a coronal plane tilted parallel to the long axis of the sacroiliac
joint (SI joint) with 4-mm slice thickness and 12 slices
acquired. Sequences were as follows: T1-weighted spin
echo (SE; time to recovery [TR] 517– 618 msec, time to
echo [TE] 13 mecs) and STIR (TR 2,720 –3,170 mecs, time
to inversion 140 msec, TE 38 – 61 mecs). Patients in cohort
B also had T1-weighted SE sequences performed after
intravenous administration of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA), 0.1 mmole/kg body
weight. Detailed protocol description and multiple scout
images allowed repetitive acquisition of SI joint sequences
in near identical anatomic sites and angles for the posttreatment images. The specific MRI parameters for acquiring sacroiliac images are provided on our website (available at www.altarheum.com/research.html).
Scoring of MRI lesions. Our scoring method for active
inflammatory lesions in the SI joint relied on the use of a
T2-weighted sequence that incorporates suppression of
normal marrow fat signal. In other sequences, signal from
marrow fat frequently obscures signal emanating from
marrow edema associated with inflammation. Consequently, the use of fat suppression improves sensitivity for
detection of abnormal water content.
Scoring of the SI joints was confined to those coronal
slices depicting the synovial portion of the joint. In a
preliminary overview of SI joint MR images from other
patients with AS, the synovial portion was consistently
evident in 6 consecutive coronal slices. Of the 12 acquisitions from posterior to anterior, this was typically slices 4
to 9. We therefore scored 6 consecutive coronal slices from
posterior to anterior. T1-weighted SE images were included for anatomic reference only and were not scored.
All lesions within the iliac bone and within the sacrum up
to the sacral foramina were scored. Increased signal within
the sacroiliac joint space or in the ligamentous portion of
the joint was not scored.
Validation of an MRI Tool For Scoring Sacroiliac Joint Inflammation
705
Scoring method. Figure 1 illustrates 2 examples of the
scoring method. Each SI joint is divided into 4 quadrants:
upper iliac, lower iliac, upper sacral, and lower sacral. The
presence of increased signal on STIR in each of these 4
quadrants was scored on a dichotomous basis, where 1 ⫽
increased signal and 0 ⫽ normal signal. The maximum
score for abnormal signal in the 2 SI joints of 1 coronal
slice was therefore 8. Joints that included a lesion exhibiting intense signal were each given an additional score of
1 per slice that demonstrated this feature. Similarly, each
joint that included a lesion demonstrating continuous increased signal of depth ⱖ1 cm from the articular surface
was also given an additional score of 1. This brought the
maximal score for a single coronal slice to 12. The scoring
was repeated in each of the 6 consecutive coronal slices
leading to a maximum score of 72.
Figure 1. A, Example 1 of the Spondyloarthritis Research Consortium of Canada (SPARCC) magnetic resonance imaging (MRI)
index for scoring inflammatory lesions in the sacroiliac joint. The
figure represents a STIR sequence and a coronal slice through the
synovial portion of the joint. The joint is divided into 4 quadrants
where 1 ⫽ upper illiac, 2 ⫽ upper sacral, 3 ⫽ lower sacral, and 4 ⫽
lower iliac. Total score ⫽ 5. R ⫽ 1; L ⫽ 3 ⫹ 1 (intensity). B,
Example 2 of the SPARCC MRI sacroiliac joint inflammation
index scoring method. Total score ⫽ 8. R ⫽ 2 ⫹ 1 (depth); L ⫽ 4 ⫹
1 (depth).
Definition of abnormal lesion on STIR sequence. Sacral
interforaminal bone marrow signal formed the reference
for assignment of normal signal in the joint. Three non-AS
control (mechanical back pain) images and a set of reference AS images were included to facilitate the designation
of abnormal increased signal.
Scoring of depth and intensity. The signal from presacral blood vessels defined a lesion that was scored as
intense. A lesion was graded as deep if there was a homogeneous and unequivocal increase in signal extending
over at least 1 cm from the articular surface. Assessment
of depth was made possible by including a scale on the
image.
MRI reading exercises. A unique MRI study number
was allocated for each patient by a technologist unconnected with the study, thereby ensuring blinding to all
patient demographics. Assessment was based on printed
film to allow multiple readers to assess scans that were set
up on multiple view boxes at the same time. Each film was
only identified by the MRI study number and images were
read in random order. Pre- and posttreatment images were
scored concurrently with the observer blinded to time
sequence. For assessment of intraobserver reproducibility,
MR images were randomly scored on 2 separate occasions
2 weeks apart after allocation of different MRI study numbers for the second reading exercise and rerandomization
of time sequence by an independent observer who was not
involved in the scoring exercise.
MRI readings were preceded by 2 training exercises
conducted by a rheumatologist and a radiologist (WPM
and RGWL) at the University of Alberta site to determine
feasibility of the scoring method and obtain preliminary
data on reproducibility. In addition, a set of 6 reference
MR images from other patients with AS were chosen,
depicting the range of abnormalities typically seen on MRI
in patients with clinically active AS. Electronic images of
these reference AS cases were then sent to readers at a
second site, the University of Toronto, and the scoring
method was discussed by teleconference. Scoring of MRI
lesions at the University of Toronto site then ensued without a formal training exercise.
Cohort A readings. SI joint lesions in MR images from
11 patients with AS and 3 controls with non-specific back
pain were blindly scored by 3 independent readers, 2
radiologists (RGWL and SSD) and 1 rheumatologist
(WPM), at the University of Alberta at 2 time points. In
addition, these MR images were scored blindly at a single
time point by 2 independent readers at the University of
Toronto, a radiologist (DS) and a rheumatologist (RDI).
These exercises allowed the assessment of interobserver
reliability of the scoring method across both sites.
Cohort B readings. SI joint STIR and Gd-DTPA– enhanced lesions in MR images from 11 patients with AS and
3 controls with non-specific back pain were blindly scored
by the same 3 independent readers at the University of
706
Maksymowych et al
Table 1. Distribution of lesion scores in sacroiliac joints of 22 patients with AS as
recorded by 3 readers according to the Spondyloarthritis Research Consortium of
Canada magnetic resonance imaging scoring of STIR sequences*
Parameter
Mean ⴞ SD
Median
(25/75 percentiles)
Range
Total score
Right SI joint score
Left SI joint score
Median coronal slice score
Minimum coronal slice score
Maximum coronal slice score
9.6 ⫾ 10.1
5.6 ⫾ 6.0
3.9 ⫾ 5.2
1.5 ⫾ 1.8
0.6 ⫾ 1.3
2.9 ⫾ 2.3
7.0 (1.0–14.25)
3.25 (1.0–8.0)
2.0 (0–5.5)
1.0 (0–2.5)
0.0 (0–0)
2.75 (1–4)
0–39.5
0–23
0–20.5
0–6.5
0–5.5
0–9
* The scheme scores 6 coronal slices per patient. AS ⫽ ankylosing spondylitis; SI joint ⫽ sacroiliac joint.
Alberta at baseline and at 24 weeks after randomization of
the patients to either placebo or infliximab (3:8). These
exercises allowed us to examine not only the responsiveness of the scoring method but also the relative reliability
and responsiveness of the 2 imaging techniques.
Statistical analysis. Descriptive statistics (mean, median, SD), frequency histograms, and box plots with median, interquartile ranges, and maximum and minimum
values were used to describe the overall distribution of
scores. The intra- and interobserver reproducibility were
calculated using analysis of variance to provide an intraclass correlation coefficient (ICC). A 2-way mixed effects
model with the observer as a fixed factor was used. A value
⬎0.6 was designated as representing good reproducibility,
⬎0.8 represented very good reproducibility, and ⬎0.9 represented excellent reproducibility. The P value for the
significance of the F statistic for each ICC is presented.
Reproducibility was also examined using Bland-Altman
plots and 95% limits of agreement. The intrarater variance
was used to calculate the smallest detectable difference
(SDD) between 2 readings by a single rater for a single
patient and was calculated by multiplying the SD of the
differences by 1.96.
The effect size (ES) and the standardized response mean
(SRM) were used to assess responsiveness. Values of 0.20,
0.50, and 0.80 or greater were considered to represent
small, moderate, and large degrees of responsiveness, respectively. Discrimination was not assessed because the
open-label phase of the clinical trial is ongoing and treatment codes remain unbroken at this time.
towards the lower end of the scoring range per coronal
slice (0 –12).
Reproducibility of scores. Intraobserver. Overall, intraobserver reproducibility was excellent not only for the
total score (0.90 – 0.98) but also for the distribution of
scores between the individual coronal slices of the SI joint,
with similar reproducibility for median, minimum, and
maximum coronal slice scores (Table 2). Intraobserver reproducibility was even better for the 2 radiologists (readers
2 and 3). ICC values were the same when the 3 controls
were included in the analysis (data not shown). Mean total
SI joint scores for the controls were 1.2, 1.7, and 2.7 for the
3 readers, respectively, indicating appropriate definition
of abnormal STIR signal. SDD values ranged from 4.7 to
12.9 for total SI joint score and were smaller for the 2
radiologists (5.4 and 4.7 for readers 2 and 3, respectively)
than for the rheumatologist (12.9).
Interobserver reproducibility (single site) of status score.
Figure 2 shows that the median, interquartile range, and
maximum plus minimum values for the SI joint lesion
scores from 22 patients recorded at the University of Alberta were comparable between the 3 readers. The scores
represent the mean of the 2 values recorded for crossTable 2. Intraobserver reproducibility of sacroiliac joint
lesion scores in 11 patients with AS (cohort A) as
recorded by 3 readers according to the Spondyloarthritis
Research Consortium of Canada magnetic resonance
imaging scoring scheme*
Intraobserver ICC
RESULTS
Distribution of scores. Scores for lesions in the sacroiliac joints were distributed towards the lower end of the
scoring range (0 –72) (Table 1). These results were based on
data from 22 patients, 11 patients in cohort A and baseline
data from 11 patients in cohort B. Five patients were noted
to have fused sacroiliac joints, which likely accounts for
the clustering of scores at the lower end of the range. Table
1 also shows that scoring only the single most severely
affected coronal slice (maximum coronal slice score) also
resulted in a median score (2.75) that was distributed
Parameter
Total SI joint score
Median SI joint coronal
slice score
Minimum SI joint coronal
slice score
Maximum SI joint coronal
slice score
Reader 1 Reader 2 Reader 3
0.90†
0.90†
0.98†
0.98†
0.98†
0.94†
0.74‡
0.98†
0.98†
0.85†
0.96†
0.92†
* AS ⫽ ankylosing spondylitis; ICC ⫽ intraclass correlation coefficient; SI joint ⫽ sacroiliac joint.
† P ⬍ 0.0001
‡ P ⫽ 0.003
Validation of an MRI Tool For Scoring Sacroiliac Joint Inflammation
707
Table 4. Comparison of interobserver reproducibility of
sacroiliac joint STIR and Gd-DTPA status and change
scores among 3 readers in 11 AS patients randomized to
placebo:infliximab (3:8) for 24 weeks*
Parameter
Mean ⴞ SD
ICC
P
STIR status
STIR change
Gd-DTPA status
Gd-DTPA change
6.5 ⫾ 5.7
⫺0.3 ⫾ 4.2
9.7 ⫾ 9.0
1.5 ⫾ 4.9
0.67
0.53
0.70
0.79
⬍ 0.001
0.002
⬍ 0.001
⬍ 0.001
* Gd-DTPA ⫽ gadolinium diethylenetriaminepentaacetic; AS ⫽ ankylosing spondylitis; ICC ⫽ intraclass correlation coefficient.
Figure 2. Median, interquartile range, maximum and minimum
values for sacroiliac joint magnetic resonance imaging STIR
scores from 22 patients with ankylosing spondylitis recorded by 3
readers at the University of Alberta. Scores represent mean of the
2 readings performed on patients in cross-sectional cohort A (n ⫽
11) and the baseline readings of patients randomized to treatment
with infliximab/placebo (cohort B) (n ⫽ 11).
sectional cohort A patients (n ⫽ 11) and the baseline
(pretreatment) values for cohort B patients (n ⫽ 11). Overall, interobserver reproducibility was very good not only
for the total SI joint score (ICC 0.89) but also for the
distribution (median, maximum values) of scores among
individual SI joint slices (Table 3). Bland-Altman plots of
interobserver differences plotted against the mean of the
interobserver scores showed that reader 1 tended to score
higher than readers 2 and 3 (data not shown).
Interobserver reproducibility for total SI joint score was
very good (ICC 0.90) for the 2 readers at the University of
Toronto site despite no formal training exercise (Table 3).
Reproducibility was less good when only the score for the
single most severely affected coronal slice (maximum
coronal slice score) was analyzed.
Interobserver reproducibility (2 sites) of status score.
Interobserver reproducibility was very good when total SI
joint scores from both sites (5 readers) were analyzed (ICC
0.86) and was less good when only the score for the single
most severely affected coronal slice (maximum coronal
slice score) was analyzed (ICC 0.71) (Table 3).
Interobserver reproducibility of change score. This data
was available for the 11 patients in cohort B that were
randomized to placebo/infliximab (3:8) for 24 weeks. Ta-
ble 4 compares interobserver reproducibility of status and
change scores for STIR and Gd-DTPA sequences in cohort
B patients. Reproducibility was less good for change in
STIR lesion score (ICC 0.53) where complete fusion was
noted in 3 patients and features supporting the presence of
marrow edema were subtle in the remaining patients. Reproducibility of change scores was somewhat better when
Gd-DTPA– enhanced sequences were analyzed (ICC 0.79).
Responsiveness of scoring method. Responsiveness of
the SI joint scoring method was poor when either STIR
(ES ⫽ 0.06, SRM ⫽ 0.08) or Gd-DTPA (ES ⫽ ⫺0.20, SRM ⫽
⫺0.33) sequences were used, but 3 patients had fused
joints and features indicating marrow edema were subtle
in the remaining patients. This is further highlighted by
the low scores for active inflammation on STIR images
(Table 1).
DISCUSSION
We have developed an outcome tool for scoring inflammation by MRI in the SI joints that appears to meet the
standards of feasibility and reproducibility. Innovations
that facilitate scoring include the availability of reference
films, objective definitions of abnormal signal on STIR
sequences, high-intensity signal, and pronounced depth of
signal, together with a simplified scoring sheet that allows
us to both improve our ability to detect abnormal MRI
signal and record the abnormalities within a reasonable
time frame per patient (5–10 minutes). The feasibility and
simplicity of the scoring method are reinforced by the
Table 3. Interobserver reproducibility of sacroiliac joint lesion status scores in patients
with AS as recorded by 3 readers at the University of Alberta and 2 readers at the
University of Toronto according to the Spondyloarthritis Research Consortium of
Canada magnetic resonance imaging index*
Interobserver ICC
Parameter
University
of Alberta
University
of Toronto
Combined
Total SI joint score
Median SI joint coronal slice score
Maximum SI joint coronal slice score
0.89†
0.85†
0.84†
0.90†
0.85†
0.54‡
0.86†
0.79†
0.71†
* AS ⫽ ankylosing spondylitis; ICC ⫽ intraclass correlation coefficient; SI joint ⫽ sacroiliac joint.
† P ⬍ 0.0001
‡ P ⫽ 0.04
708
reliability of scores recorded at the University of Toronto
site despite no formal training exercise.
The use of gadolinium is costly and nearly doubles total
scanning time to 1 hour, which is particularly uncomfortable for patients with AS. Our data show comparable reproducibility between gadolinium and STIR sequences for
status scores although reproducibility of change scores
may be somewhat better with gadolinium. These findings
will require further examination in a cohort of patients
with a broader spectrum of inflammatory disease, as most
of our patients in cohort B had chronic changes and onethird had fused SI joints. This was also the reason why we
did not examine the construct validity of this scoring
method.
A further limitation of our study was that we were not
able to assess the discriminant properties of our instrument. The open-label phase of the infliximab trial is ongoing and treatment codes remain unbroken. We are therefore unable to analyze changes in lesion scores by
treatment allocation. The responsiveness of the scoring
method for SI joint inflammation will also require further
analysis in patients with a broader spectrum of inflammatory disease.
Two additional methods for scoring inflammation in the
SI joints have been published, although as yet neither has
been comprehensively validated (16,17). One report also
described a semiquantitative method for scoring sacroiliitis that was based on the degree of gadolinium enhancement from baseline during dynamic MRI (12). Inflammation was graded according to gadolinium enhancement of
⬍20% (no inflammation), 20 –90% (latent sacroiliitis), and
⬎90% (florid inflammation) of a region of interest that was
subjectively designated. This method performed well
when validated against patient symptomatology and the
response to computed tomography-guided sacroiliac cortisone injections (13). Primary drawbacks to this method
include the costs and lengthy scan times associated with
the use of gadolinium, the requirement for special technical expertise, and the difficulty in reproducing regions of
interest on posttreatment MRI. A second method for scoring
sacroiliitis has been published in abstract form (17). The
SI joints were divided into quadrants and the extent of inflammation in each quadrant was graded for severity, although a method for defining abnormal signal was not provided. Reproducibility across the 5 participating sites was
poor (ICC⬍0.5), however, and in developing our instrument
we similarly noted that reproducibility was poor when increased signal was graded for severity rather than being
scored in a dichotomous manner as in our current scoring
scheme (data not shown). A third scoring scheme for sacroiliitis has also proposed grading the extent of BME noted on
STIR and the degree of contrast enhancement on each side of
the SI joint (16). An overall score is then calculated based on
the sum of scores for BME and gadolinium enhancement in
both the bone marrow and the joint space. Interobserver
agreement was poor (kappa ⫽ 0.29). We also noted poor
reproducibility of joint space inflammation scores during the
pilot development of our instrument, and therefore we did
not incorporate scoring of joint space inflammation into our
instrument (data not shown).
The assessment of feasibility, truth, and discrimination
Maksymowych et al
of our instrument will now require further validation
across sites, as has been organized in previous Outcome
Measures in Rheumatology Clinical Trials exercises. In
addition, further validation of the scoring method for inflammation in the SI joints should be carried out in patients at an earlier stage of disease prior to the development of significant chronic features of disease.
ACKNOWLEDGMENT
The authors wish to express their gratitude to Medical
Imaging Consultants for all MRI scans of control subjects
and SI joint MRI scans in the patients with AS.
REFERENCES
1. Van der Heijde D, Calin A, Dougados M, Khan MA, van der
Linden S, Bellamy N. Selection of instruments in the core set
for DC-ART, SMARD, physical therapy, and clinical record
keeping in ankylosing spondylitis: progress report of the
ASAS Working Group. J Rheumatol 1999;26:951– 4.
2. Garrett S, Jenkinson T, Kennedy LG, Whitelock H, Gaisford P,
Calin A. A new approach to defining disease status in ankylosing spondylitis: the Bath Ankylosing Spondylitis Disease
Activity Index. J Rheumatol 1994;21:2286 –91.
3. Dougados M, Gueguen A, Nakache JP, Velicitat P, Zeidler H,
Veys E, et al. Clinical relevance of C-reactive protein in axial
involvement of ankylosing spondylitis. J Rheumatol 1999;26:
971– 4.
4. Spoorenberg A, van der Heijde D, de Klerk E, Dougados M, de
Vlam K, Mielants H, et al. Relative value of erythrocyte sedimentation rate and C-reactive protein in assessment of disease
activity in ankylosing spondylitis. J Rheumatol 1999;26:
980 – 4.
5. Maksymowych WP, Lambert RG. MR imaging of the sacroiliac
joints: How? Why? When? So what? J Clin Rheumatol 2000;
6:305– 8.
6. Ryan PJ, Fogelman I. The bone scan: where are we now?
Semin Nucl Med 1995;25:76 –91.
7. Ahlstrom H, Feltelius N, Nyman R, Hallgren R. Magnetic
resonance imaging of sacroiliac joint inflammation. Arthritis
Rheum 1990;33:1763–9.
8. Bollow M, Braun J, Hamm B, Eggens U, Schilling A, Konig H, et
al. Early sacroiliitis in patients with spondyloarthropathy: evaluation with dynamic gadolinium-enhanced MR imaging. Radiology 1995;194:529 –36.
9. Bollow M, Biedermann T, Kannenberg J, Paris S, SchauerPetrowski C, Minden K, et al. Use of dynamic magnetic resonance imaging to detect sacroiliitis in HLA-B27 positive and
negative children with juvenile arthritides. J Rheumatol 1998;
25:556 – 64.
10. Blum U, Buitrago-Tellez C, Mundinger A, Krause T, Laubenberger J, Vaith P, et al. Magnetic resonance imaging (MRI) for
detection of active sacroiliitis: a prospective study comparing
conventional radiography, scintigraphy, and contrast enhanced MRI. J Rheumatol 1996;23:2107–15.
11. Oostveen J, Prevo R, den Boer J, van de Laar M. Early detection of sacroiliitis on magnetic resonance imaging and subsequent development of sacroiliitis on plain radiography: a prospective, longitudinal study. J Rheumatol 1999;26:1953– 8.
12. Braun J, Bollow M, Eggens U, Konig H, Distler A, Sieper J. Use
of dynamic magnetic resonance imaging with fast imaging in
the detection of early and advanced sacroiliitis in spondylarthropathy patients. Arthritis Rheum 1994;37:1039 – 45.
13. Braun J, Bollow M, Seyrekbasan F, Haberle HJ, Eggens U,
Mertz A, et al. Computed tomography guided corticosteroid
injection of the sacroiliac joint in patients with spondyloarthropathy with sacroiliitis: clinical outcome and follow up by
dynamic magnetic resonance imaging. J Rheumatol 1996;23:
659 – 64.
Validation of an MRI Tool For Scoring Sacroiliac Joint Inflammation
14. Bollow M, Fischer T, Reisshauer H, Backhaus M, Sieper J,
Hamm B, et al. Quantitative analyses of sacroiliac biopsies in
spondyloarthropathies: T cells and macrophages predominate
in early and active sacroiliitis: cellularity correlates with the
degree of enhancement detected by magnetic resonance imaging. Ann Rheum Dis 2000;59:135– 40.
15. 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– 8.
709
16. Puhakka KB, Jurik AG, Egund N, Schiottz-Christensen B,
Stengaard-Pedersen K, van Overeem Hansen G, et al. Imaging
of sacroiliitis in early seronegative spondylarthropathy: assessment of abnormalities by MR in comparison with radiography and CT. Acta Radiol 2003;44:218 –29.
17. Marzo-Ortega H. Interreader agreement in the assessment of
magnetic resonance imaging of the sacroiliac joints in
spondyloarthropathy: the 1st MISS study [abstract]. Arthritis
Rheum 2002;46 Suppl:S428.
Документ
Категория
Без категории
Просмотров
3
Размер файла
143 Кб
Теги
spondyloarthritis, joint, index, sacroiliac, research, inflammation, magnetic, imagine, ankylosis, canada, assessment, resonance, consortia, spondylitis
1/--страниц
Пожаловаться на содержимое документа