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Role of Abdominal CT, When Available in Patients?? Records, in the Evaluation of Degenerative Changes of the Sacroiliac Joints
Abstract
To determine the role of abdominal computed tomography (CT) that had been performed for other reasons, in the evaluation of degenerative changes of the sacroiliac joints, the authors performed a retrospective review of the sacroiliac joints of 100 patients, all of whom had an abdominal CT scan and a plain abdominal and/or pelvic roentgenogram in their files. The results indicate that, when available in the patient's record, abdominal CT scans provide substantial additional information in the evaluation of degenerative changes of the sacroiliac joints at no extra cost. The authors' results also suggest that after the age of 55, the patient's age does not seem to influence the extent of sacroiliac joint narrowing, which does appear to be affected by the presence of coexisting diffuse idiopathic skeletal hyperostosis.
... In concordance with other reports, SJ degeneration is common in non-symptomatic adults in the early decades of life and increases with age [2,6,28,35]. Past studies have shown that degeneration of the SJ is more prevalent in the elderly population, but these changes tend to plateau in the higher age groups [1, 2,6,28,38]. Given the high prevalence of painfree SJ degeneration, physicians must be cautious in attributing low back pain to degenerative changes of the SJ seen on cross-sectional imaging [2,6]. ...
... [1] 50-70+ years of age, Shibata et al. [28] 20-70+ years of age, Yagan et al. [38] 55 years and over, and Faflia et al. [7] aged 15 to 83 years. Further studies [2,6,7] were found that degenerative changes increased with age in asymptomatic patient groups similar to age group of this research. ...
... Further studies [2,6,7] were found that degenerative changes increased with age in asymptomatic patient groups similar to age group of this research. However, previous studies [1, 2,6,7,28,38] showed that the prevalence of degenerative changes in non-asymptomatic and 60+ age group was very high compared to our study. ...
BACKGROUND: The sacroiliac joint has a structure in which the direction of the load relative to the articular surface is irrational, as the joint surface is not perpendicular to the trunk load axis; it is likely to incur more degenerative changes than other weight-bearing joints. MATERIALS AND METHODS: This retrospective study consisted of a total of 145 cases — 104 (71.7%) men and 41 (28.3%) women — who were referred to Gaziantep University Medical Faculty Radiology Department Polyclinic for pelvic computed tomography (CT) from 2013 to 2018. The mean age was 33.5 years (range: 18–60 years). Pelvis CT images were performed according to the exclusion criteria specified by the experienced orthopaedic surgeon. Patients were excluded from the study if they were younger than the age of 18, had a condition involving the sacroiliac joint, had an endocrine disorder, or had a history of a trauma affecting the pelvis CT examination. RESULTS: In this current study, six types of anatomic variations were detected. Iliosacral complex variation has been determined as the most common type of variation. The incidence of variations of sacroiliac joint in all cases was 28.9%. Degenerative changes were seen in 5.5% of patients fewer than 30 years of age. When it comes to the patients whose age range is 30–60, the percentage of the degenerative changes is 12.4%. In patients who were 30 years and older, the prevalence of degenerative changes increased progressively with increasing age. CONCLUSIONS: In this study, it is thought that the knowledge of variations in normal population and degenerative changes will contribute to the better understanding of normal morphological structure of sacroiliac joint and to the anatomical literature. It’s seen that there is not a statistically significant relationship between degenerative changes and anatomical variations.
... DISH may also affect the sacroiliac joints, which can further result in being mistaken for sacroiliitis of AS. The upper (ligamentous) portion of the joint may show changes, such as vacuum phenomenon, narrowing, sclerosis, and even partial or complete bony ankylosis [2,3,[28][29][30][31]. The lower two-third (synovial) part of the joint is spared. ...
... The lower two-third (synovial) part of the joint is spared. However, ossifi cation of the joint capsule on the anterior surface of the joint may occur, resembling the obliteration of the sacroiliac joints on anteroposterior pelvic radiograph that may erroneously be interpreted as postinfl ammatory ankylosis of the joint [2,3,[28][29][30][31][32]. CT can be useful in these cases by showing the normal aspect of joint space and bony margins, and presence of the anterior capsular ossifi cations [30,31]. ...
... The lower two-third (synovial) part of the joint is spared. However, ossifi cation of the joint capsule on the anterior surface of the joint may occur, resembling the obliteration of the sacroiliac joints on anteroposterior pelvic radiograph that may erroneously be interpreted as postinfl ammatory ankylosis of the joint [2,3,[28][29][30][31][32]. CT can be useful in these cases by showing the normal aspect of joint space and bony margins, and presence of the anterior capsular ossifi cations [30,31]. ...
Diffuse idiopathic skeletal hyperostosis (DISH) and ankylosing spondylitis (AS) share involvement of the axial skeleton and
peripheral entheses. Both diseases produce bone proliferations in the later phases of their course. Although the aspect of
these bone proliferations is dissimilar, confusion of radiologic differential diagnosis between the two diseases exists mostly
as a consequence of a lack of awareness of their characteristic clinical and radiographic features. The confusion may extend
to the clinical field because both advanced DISH and advanced AS may cause the same limitations of spinal mobility and postural
abnormalities. However, the radiologic spinal findings are so different that changes due to each disease can be recognized
even in patients in whom both diseases occur. This article reviews the clinical and radiologic characteristics that should
help clinicians differentiate between the two diseases without much difficulty.
... The sacroiliac joint vacuum phenomenon (SIJ VP) is not an uncommon finding in adults. [1][2][3] When radiologists face abdominopelvic CT (AP CT), little attention is paid to the SIJ. However, AP CT can provide information about the SIJ, if we attempt to observe the SIJ. ...
... However, AP CT can provide information about the SIJ, if we attempt to observe the SIJ. [1][2][3] The SIJ VP has been reported in approximately 31-34% of adults. 1,4 In addition, it is observed more frequently in females and in patients older than 60 years. 1 Moreover, it is considered an age-related morphological variant, and obesity is believed to affect such degenerative changes in the SIJ. 4 To our knowledge, there has been no report on the SIJ VP among only paediatric patients, and data are lacking on its prevalence and clinical significance in this group. ...
Objective:
To assess the incidence of the sacroiliac joint vacuum phenomenon (SIJ VP) in paediatric patients and the relationship between the presence of VP and clinical factors, such as age, sex, and body mass index (BMI).
Methods:
We retrospectively reviewed clinical data and imaging findings of 60 patients who underwent abdomino-pelvic computed tomography (A-P CT) between January 2015 and June 2015. Patients were divided into VP group and non-VP group based on the presence/absence of VP , and the groups were compared.Additionally, other degenerative changes in the SIJ were recorded.
Results:
The SIJ VP was detected in 19 patients (31.6%). There were no significant differences in sex distribution between VP and non-VP groups (p = 0.781). The age of VP group was significantly higher than non-VP group (p < 0.001). After adjusting BMI for age, there was no significant association between high BMI and the presence of the SIJ VP (p = 0.326). Other degenerative changes were not noted in any of the patients.
Conclusion:
The SIJ VP is not uncommon finding in paediatric patients. The prevalence of SIJ VP in paediatric patients is similar to its prevalence in adults. The SIJ VP is related with patient age, but not with sex or BMI in children and young adolescents.
Advances in knowledge:
A-P CT can provide information about the SIJ, if it is required to assess the SIJ in paediatric patient.
... The lower two-thirds (synovial area) of the joint is spared. However, ossification of the joint capsule on the anterior surface of the joint can occur, which sometimes resembles fusion of the SI joints on anteroposterior pelvic radiographs and may mistakenly be interpreted as postinflammatory ankylosis of the joint (grade 4 sacroiliitis) 9 . Computed tomography (CT) can be helpful in these cases by demonstrating the normal aspect of the joint space and bony margins together with the presence of the anterior capsular ossification 9 . ...
... However, ossification of the joint capsule on the anterior surface of the joint can occur, which sometimes resembles fusion of the SI joints on anteroposterior pelvic radiographs and may mistakenly be interpreted as postinflammatory ankylosis of the joint (grade 4 sacroiliitis) 9 . Computed tomography (CT) can be helpful in these cases by demonstrating the normal aspect of the joint space and bony margins together with the presence of the anterior capsular ossification 9 . ...
Spondyloarthritis (SpA) and diffuse idiopathic skeletal hyperostosis (DISH) are different diseases obliged to converge1.
SpA is an inflammatory disease involving the axial skeleton and the peripheral entheses and joints and showing a wide clinical spectrum that encompasses ankylosing spondylitis (AS), reactive arthritis (ReA), psoriatic arthritis (PsA), arthritis related to inflammatory bowel disease (IBD), and forms that do not meet established criteria for these definite categories and are designated as undifferentiated SpA (uSpA)2,3. Recently, classification criteria have been suggested by ASAS (Assessment in Spondyloarthritis International Society) for axial and peripheral SpA4,5. In contrast, DISH is a degenerative condition characterized by calcification and ossification of ligaments and entheseal sites in the axial and the peripheral skeleton6. Classification criteria for DISH used so far require involvement of the spine6 although extravertebral bone proliferations are frequent and characteristic and may precede axial changes7,8. An international study for the development of new criteria is in progress8.
At the beginning of the story, AS and DISH resembled each other only on radiographs because of the bony outgrowths they produce in the spine1. Clinically, they were considered very different diseases. Symptoms of AS begin at a young age, frequently in second and third decades, and consist of inflammatory back pain and buttock pain, reduced spinal movement, and progressive typical postural abnormalities known as “Bechterew stoop.” In contrast, DISH was considered a disease with an asymptomatic course or with mild dorsolumbar pain and/or some restriction of spinal motion.
Radiographically, DISH is characterized by “flowing mantles” of ossifications occurring in the anterior longitudinal …
Address correspondence to Dr. Olivieri, Rheumatology Department of Lucania-San Carlo Hospital, Contrada Macchia Romana, 85100-Potenza, Italy. E-mail: ignazioolivieri{at}tiscalinet.it
... The figures are close to those of a study done on 10-mm-thick axial body CT slices (13), where a decrease in joint space width was seen, from 2.3 mm in patients aged 15Á39 years to 1.9 mm in patients over 40. In a retrospective study on patients over 55 years of age, using abdominal CT, no further reduction in joint space width after age 55 was shown (16). In the current study, patients with bilateral grade 3 sacroiliitis in general had slightly narrower joint spaces than patients with grade 0, with a tendency toward progressive joint space reduction over the years. ...
... In DISH, sacroiliac joint abnormalities may include osteophytes and coexistent osteoarthritis, particularly in older patients. These changes are associated with sacroiliac joint space narrowing and paraarticular bridging osteophytes (16,26). Ossification of the superior but not inferior ligamentous portion of the sacroiliac joints has previously been reported as statistically significant for DISH (27). ...
Sacroiliitis in ankylosing spondylitis has frequently been graded radiographically using the New York (NY) criteria, which also have been applied in computed tomography (CT).
To validate the grading of the NY criteria in CT of the sacroiliac joints.
With the aid of the NY criteria, assessment of inflammatory and degenerative changes was made in 1304 CT studies. Assessment included erosions, the distribution, type, and width of sclerosis, and the involvement of the joints in sacroiliitis, as well as of normal anatomic variants such as joint space width and shape.
There was definite radiological sacroiliitis in 420 joints in 251 patients. Among these, more than two-thirds of the joint was involved in 71.0% of the affected joints. Sclerosis of the ilium was much more prevalent than sacral sclerosis. With increasing NY grade, iliac sclerosis, width, and extent increased, transition from sclerosis to normal bone became indistinct, and the structure of sclerosis was more inhomogeneous. Erosions of the joint surfaces were localized predominantly on the iliac side.
Only erosions seem to be a valid solitary diagnostic sign. Solitary erosions need supplemental evidence from other inflammatory signs. Inflammatory sclerosis may be distinguished from degenerative sclerosis, and can sometimes support early diagnosis. Joint space width, joint shape, bone mineral content, or enthesopathy have no place in sacroiliitis diagnosis on CT. The NY criteria are not ideal for use with CT. A practical classification of sacroiliitis on CT is proposed, with a grading of no disease, suspected disease, and definite disease.
... Another hint that supports this theory is the pelvic involvement, mainly the SI joint. The SI joint degenerative changes are common in DISH, which is characterized by joint space narrowing, osteophytes, subchondral sclerosis, cysts, vacuum phenomena, and ankyloses [24,25]. Moreover, the ankylosed SI joint typically involves its upper non-synovial portion, characterized by para-articular bony bridging, while the lower synovial portion is spared [26,27]. ...
Ossification of the posterior longitudinal ligament (OPLL) is considered a multifactorial condition characterized by ectopic new bone formation in the spinal ligament. Recently, its connections with inflammation as well as sacroiliac (SI) joint ankylosis have been discussed. Nevertheless, whether inflammation, spinal ligament ossification, and SI joint changes are linked in OPLL has never been investigated. In this study, whole-spinal computed tomography and serum high-sensitive C-reactive protein (hs-CRP) levels were obtained in 162 patients with cervical OPLL. Ossification lesions were categorized as plateau and hill shapes. Accordingly, patients were divided into plateau-shaped (51 males and 33 females; mean age: 67.7 years) and hill-shaped (50 males and 28 females; mean age: 67.2 years) groups. SI joint changes were classified into four types and three subtypes, as previously described. Interactions among ossification shapes, hs-CRP levels, and morphological changes in the SI joint were investigated. The plateau shape was more common in the vertebral segments (59.5%), compared to the hill shape, which was predominant in the intervertebral regions (65.4%). Serum hs-CRP levels in the plateau-shaped group (0.11 ± 0.10 mg/dL) were significantly higher than those in the hill-shaped group (0.07 ± 0.08 mg/dL). SI joint intra-articular fusion was the main finding in the plateau-shaped group and showed significantly higher hs-CRP levels compared to the anterior para-articular bridging, which more frequently occurred in the hill-shaped group. Our findings suggested a possible inflammation mechanism that might contribute to the new bone formation in OPLL, particularly the plateau shape.
... Sacroiliac capsular bridging has been described in patients with DISH. 7 This may obliterate the sacroiliac joint space giving the impression of fusion of the joint due to AS on the anteroposterior view. In these cases, CT shows normal sacroiliac joint space and surfaces together with anterior capsular bridging. ...
... Two studies have also analyzed the performance of abdominal and pelvic CT in assessing the SI joints. The first, performed in 1987, estimated the ability of CT to show the presence of degenerative lesions of the SI joints compared with conventional radiography (23). The second, more recent study, investigated the performance of abdominal and pelvic CT in establishing a diagnosis of structural sacroiliitis according to the New York criteria on 598 examinations performed on a large population aged 18-55 years. ...
Background
The presence of structural sacroiliitis is strong evidence for the diagnosis of spondyloarthritis (SpA).
Purpose
To assess the performance of abdominal computed tomography (CT) and pelvic plain radiography for the diagnosis of structural sacroiliitis compared with sacroiliac CT (SI joint CT) considered the reference technique in patients with SpA.
Material and Methods
All SpA patients eligible for biologic treatment were selected from 2005 to 2012. An assessment of sacroiliitis was based on radiography according to the modified New York criteria and on abdominal CT and SI joint CT scans depending on the presence of erosion on at least two consecutive slices. A senior rheumatologist and radiologist independently scored the grade and diagnosis of structural sacroiliitis for the three imaging modalities. After a consensus reading of conflicting examinations (radiography and CT), a final diagnosis of structural sacroiliitis was attained.
Results
Of the 72 patients selected, sacroiliitis was diagnosed on radiography, abdominal CT, and SI joint CT in 40, 31, and 44 patients, respectively. Inter-reader agreements for the grade of sacroiliitis were substantial for the three imaging modalities, with a weighted kappa range of 0.63–0.75 (95% confidence interval [CI], 0.52–0.83), and they were moderate for the diagnosis of sacroiliitis, with a kappa range of 0.50–0.55 (95% CI, 0.32–0.74). The sensitivity and specificity were 79.1% and 70.5%, respectively, for radiography and 82.1% and 100%, respectively, for abdominal CT.
Conclusion
This study demonstrates the relevance of abdominal CT for the diagnosis of structural sacroiliitis, with good sensitivity and excellent specificity. These imaging techniques avoid unnecessary examinations.
... The sacroiliac region has been the subject of few anatomical studies [14,15,20], whereas numerous CT investigations on SIJ were carried out on normal anatomy [29], age-related degenerative changes [4,7,8,12,25,28,32], anatomical variations [4,6,19] in asymptomatic subjects, and inflammatory changes in rheumatic conditions [1,2,5,11,13]. None of these studies specifically dealt with the extra-articular components of the sacroiliac region. ...
Purpose:
To identify and describe the morphometry and CT features of the articular and extra-articular portions of the sacroiliac region. The resulting knowledge might help to avoid complications in sacroiliac joint (SIJ) fusion.
Methods:
We analyzed 102 dry hemi-sacra, 80 ilia, and 10 intact pelves and assessed the pelvic computerized tomography (CT) scans of 90 patients, who underwent the examination for conditions not involving the pelvis. We assessed both the posterior aspect of sacrum with regard to the depressions located externally to the lateral sacral crest at the level of the proximal three sacral vertebrae and the posteroinferior aspect of ilium. Coronal and axial CT scans of the SIJ of patients were obtained and the joint space was measured.
Results:
On each side, the sacrum exhibits three bone depressions, not described in anatomic textbooks or studies, facing the medial aspect of the posteroinferior ilium, not yet described in detail. Both structures are extra-articular portions situated posteriorly to the SIJ. Coronal CT scans of patients showing the first three sacral foramens and the interval between sacrum and ilium as a continuous space display only the S1 and S3 portions of SIJ, the intermediate portion being extra-articular. The S2 portion is visible on the most anterior coronal scan. Axial scans show articular and extra-articular portions and features improperly described as anatomic variations.
Conclusions:
Extra-articular portions of the sacroiliac region, not yet described exhaustively, have often been confused with SIJ. Coronal CT scans through the middle part of sacrum, the most used to evaluate degenerative and inflammatory conditions of SIJ, show articular and extra-articular portions of the region.
... Because some of our described MRI criteria differentiating the 2 diseases (ankylosis of facet joints, SIJa) also confirm the diagnostic classification criteria of Resnick (relative preservation of disc height, absence of extensive degenerative disc disease, absence of apophyseal joint bony ankylosis, and absence of sacroiliac erosion, sclerosis, or bony fusion), performing a thorough clinical and radiographic examination by conventional radiographs as the first step in a diagnostic process is recommended. Ankylosis of the SIJ might be seen in the upper (ligamentous) portion of the joint, and an ossification of the joint capsule on the anterior surface of the joint in the lower two-thirds (synovial part) sometimes leads to misinterpretation 17,30 . ...
Objective:
Discrimination of diffuse idiopathic skeletal hyperostosis (DISH) and ankylosing spondylitis (AS) can be challenging. Usefulness of whole-body magnetic resonance imaging (WB-MRI) in diagnosing spondyloarthritis has been recently proved. We assessed the value of clinical variables alone and in combination with WB-MRI to distinguish between DISH and AS.
Methods:
Diagnostic case-control study: 33 patients with AS and 15 patients with DISH were included. All patients underwent 1.5 Tesla WB-MRI scanning. MR scans were read by a blinded radiologist using the Canadian-Danish Working Group's recommendation. Imaging and clinical variables were identified using the bootstrap. The most important variables from MR and clinical history were assessed in a multivariate fashion resulting in 3 diagnostic models (MRI, clinical, and combined). The discriminative capacity was quantified using the area under the receiver-operating characteristic (ROC) curve. The strength of diagnostic variables was quantified with OR.
Results:
Forty-eight patients provided 1545 positive findings (193 DISH/1352 AS). The final MR model contained upper anterior corner fat infiltration (32 DISH/181 AS), ankylosis on the vertebral endplate (4 DISH/60 AS), facet joint ankylosis (4 DISH/49 AS), sacroiliac joint edema (11 DISH/91 AS), sacroiliac joint fat infiltration (2 DISH/114 AS), sacroiliac joint ankylosis (2 DISH/119 AS); area under the ROC curve was 0.71, 95% CI 0.64-0.78. The final clinical model contained patient's age and body mass index (area under the ROC curve 0.90, 95% CI 0.89-0.91). The full diagnostic model containing clinical and MR information had an area under the ROC curve of 0.93 (95% CI 0.92-0.95).
Conclusion:
WB-MRI features can contribute to the correct diagnosis after a thorough conventional workup of patients with DISH and AS.
... According to Arlet and Mazie`rez [6], the involvement of three contiguous vertebral bodies at the lower thoracic level is sufficient for the diagnosis of DISH. Sacroiliac capsular bridging has been described in patients with DISH [7,8]. This may give the false appearance of obliteration of the sacroiliac joint space that occurs in patients with AS on the pelvic X-ray anteroposterior view. ...
To describe a case-series of patients who presented with the typical postural abnormalities of long-standing advanced ankylosing spondylitis (AS) but were instead found to suffer from diffuse idiopathic skeletal hyperostosis (DISH).
We enrolled consecutive patients who showed postural abnormalities, which at first suggested to us the diagnosis of long-standing advanced AS, although the diagnostic process led us to the correct diagnosis of DISH. Each patient had a complete physical examination and radiographs of the spine and pelvis, and was investigated for HLA-B27 locus typing.
From 15 June 1998 to 15 June 2006, 15 patients with DISH were seen who presented with the typical postural abnormalities of long-standing advanced AS. All patients were males with a median age of 69 yrs (range 51-91). All lacked HLA-B27 and denied personal or family history of spondyloarthritis. All measurements assessing cervical, thoracic and lumbar spinal movement were abnormal.
Patients suffering from DISH can occasionally have severe limitations of spinal mobility, along with postural abnormalities that resemble long-standing advanced AS. Thus, the differential diagnosis between DISH and advanced AS is not limited to the radiological findings and can also extend to the clinical findings in the two diseases, as is highlighted by our report.
Study Design
Retrospective Cohort Study.
Objectives
Ossification of the posterior longitudinal ligament (OPLL) reveals heterotopic ossification in the spinal ligament. OPLL also tends to ossify ligaments and entheses throughout the body. However, hallmarks of sacroiliac (SI) joint ossification and its variation in OPLL have not been clarified. Here, we investigated the morphological changes in SI joints in individuals with and without OPLL.
Methods
We included 240 age- and sex-matched patients (OPLL+, 120; OPLL−, 120) in the study. SI joint variations were classified into 4 types: Type 1, normal or small peripheral bone irregularity; Type 2, subchondral bone sclerosis and osteophyte formation; Type 3, vacuum phenomenon; and Type 4, bridging osteophyte and bony fusion. Type 4 was further divided into 3 subgroups as previously described. Interactions between the ossified spinal region in OPLL and morphological changes in the SI joint were evaluated.
Results
SI joint ankylosis occurs more frequently in patients with OPLL (51.7%) than in those without (non-OPLL) (33.3%). The SI joint vacuum phenomenon (49.2%) was the main finding in non-OPLL. SI joint ankylosis in OPLL was characterized by anterior bridging and intra-articular fusion. OPLL patients with multilevel ossification tend to develop degeneration and ankylosis of the SI joints.
Conclusions
OPLL conferred a high risk of SI joint ossification compared with non-OPLL, and patients with extensive ossification had a higher rate of SI joint ankylosis. Understanding SI joint variation could help elucidate OPLL etiology and clarify the phenotypic differences in the SI joint between OPLL and other spinal disorders.
Objective:
The sacroiliac joint is an important source of low back pain and may be influenced by pathologies in adjoining structures such as the hip or the spine. This study aimed to investigate the influence of hip osteoarthritis on sacroiliac joint degeneration by examining the sacroiliac joints of hip osteoarthritis patients, focusing on the localization and quantity of vacuum phenomena.
Materials and methods:
The preoperative computed tomography (CT) of 31 female hip replacement candidates (mean age 69.1) and pelvic CT of 34 age-matched controls (mean age 67.9) were used to reconstruct the sacroiliac joints three-dimensionally. The degeneration score of the sacroiliac joints on axial view, as well as the location and volume of vacuum phenomena in the three-dimensionally reconstructed sacroiliac joints, were analyzed.
Results:
The total sacroiliac joint degeneration scores were similar in hip osteoarthritis patients and controls but the breakdown of the score revealed that joint space narrowing and vacuum phenomena in the sacroiliac joint increase in hip osteoarthritis, while osteophytes decrease. Three-dimensional reconstruction revealed that the volume of vacuum phenomena in the sacroiliac joint was significantly larger in the hip osteoarthritis group and the vacuum areas were localized in the antero-superior region of the sacroiliac joint.
Conclusion:
Our results suggest that hip osteoarthritis and sacroiliac joint degeneration are related, and that with further investigation, the sacroiliac joint may become a new treatment target in hip osteoarthritis.
Objective
To assess the performance of pelvic plain radiograph (radiography), abdominal CT and sacroiliac joint MRI (MRI) compared with sacroiliac joints CT (SI joint CT) for the diagnosis of structural sacroiliitis in a population suffering from spondyloarthritis (SpA) meeting the New York or ASAS criteria.
Methods
All SpA patients eligible for biologic treatment who received a pre-therapeutic check-up including the four imaging techniques in the same year were selected from 2005 to 2012. An assessment of sacroiliitis was based independently by a rheumatologist and a radiologist on radiography according to the modified New York criteria and on abdominal CT, MRI and SI Joint CT depending on the presence of erosion on at least two consecutive slices. A final diagnosis was established for conflicting exams.
Results
Of the 58 selected patients, sacroiliitis was diagnosed on radiography, abdominal CT, MRI and SI Joint CT in 32, 26, 34 and 35 patients, respectively. Inter-reader agreements for the grade of sacroiliitis were substantial with a weighted Kappa that varied between 0.60 and 0.76 and they were moderate for the diagnosis of sacroiliitis with a Kappa that varied between 0.45 and 0.55 for the four imaging modalities. The sensitivities of radiography, abdominal CT and MRI were 82.8%, 71.4% and 85.7% respectively and the specificities were 86.9%, 100% and 82.6% respectively with excellent accuracy and positive predictive value and good negative predictive value.
Conclusion
This study demonstrates the relevance of MRI and abdominal CT for the diagnosis of structural sacroiliitis with good sensitivities and excellent specificities. These imaging modalities may also contribute for the diagnosis of structural sacroiliitis.
Vacuum phenomenon (VP) is commonly found in sacroiliac joints, and its significance in patients with back pain has been debated. We investigated the prevalence of sacroiliac joint vacuum phenomenon (SJVP) and the rate at which it is reported on abdominopelvic and lumbosacral spine computed tomography (CT) images by body imagers and neuroradiologists. We hypothesized that it would be more common than not and that neuroradiologists would identify it more frequently than body imagers and on spine images more commonly than abdominopelvic studies due to the search for the source of back pain in the former.
CT images of the pelvis and lumbar spine from January to February 2009 were retrospectively reviewed. Six hundred fifty-two patients were studied during this period. Axial thin-section images were reviewed under default lung and bone window settings. Age, sex, and radiologist reports were assessed from electronic medical records.
The prevalence of SJVP on CT imaging was 34%, with higher rates found in female (41%, P<.001) and older (39%, P<.05) patients. Eighty-five percent of the phenomena were present bilaterally. Among the 223 patients with SJVP, only 17% were reported. There were no statistically significant differences between reporting rates for body radiologists and neuroradiologists.
SJVP is a prevalent condition with higher rates among older and female individuals. The phenomenon is underreported on CT images whether the studies performed are abdominopelvic scans or spine studies and whether they are interpreted by body imagers or neuroradiologists.
Quantifying the human vertebral geometry is important for accurate medical procedures. We aimed to characterize the neural arch (NA) shape at T1-L5. All T1-L5 dry vertebrae (N = 4,080) of 240 individuals were measured and analyzed by age, gender, and ethnicity. A 3D digitizer was used to measure the dimensions of the spinous (SP) and transverse (TP) processes, vertebral canal (VC), laminae, and isthmus. Most parameters were independent of age and ethnicity, yet greater in males than in females. Isthmus length increases from T1 (9.8 mm) to T12 (19.87 mm) and decreases from T12 to L5 (9.68 mm) with right > left in the thorax and oppositely in the lumbar region. The SP is longer than its thickness both decreasing in the upper thorax (by ca. 4mm), increasing in the lower thoracic and upper lumbar vertebrae (by 7 mm for length and ca. 14.5 mm for thickness) and decreasing again along the lower lumbar vertebrae (both by 8 mm). The TP length decreases at T1-T12 (by 13 mm) and increases at L1-L5 with left > right at T1-L5 (P < 0.003). The laminar length decreases from T1 (8.72 mm) through T5 (4.76 mm) and increases toward L5 (8.4 mm) with right > left at T1-L5 (P < 0.003). The VC is oval-shaped at T1 and T11-L5 (width > length), rounded-shape at T2 and T10 (width = length), and inverted oval-shaped at T3-T9 (length > width). In conclusion, the NA is systematically asymmetrical and dynamic in shape along the thoracic and lumbar spine. The inter-relationship with the vertebral body and articular facets is discussed.
The sacroiliac joints present unique problems in diagnosis for both the clinician and the radiologist. Each of the imaging modalities presents advantages and problems. The specific clinical problems determine whether advanced imaging modalities such as scintigraphy, CT scan, or magnetic resonance imaging will complement the information on the plain radiographs.
To describe the CT appearance of the ageing sacroiliac joints (SJ) and correlate the radiological findings with patients' gender, body mass index (BMI) and, in women, parity.
The study population included 288 consecutive patients who underwent pelvic CT for various indications not related to SJ diseases. Patients were stratified by age, BMI and parity in women. The joint space and subchondral sclerosis were assessed and the presence of osteophytes, ankylosis, erosions, subchondral cysts and vacuum phenomena were noted on bone window settings.
The widths of the SJ space and of the subchondral sclerosis on the iliac and sacral sides were 2.3+/-0.4mm, 2.5+/-1.6mm and 1.4+/-0.5mm, respectively, in patients younger than 40 years of age and 1.9+/-0.2 mm, 3.6+/-2.1 mm and 2.3+/-1.1 mm, respectively, in patients older than 40 years of age. The joint space tends to become narrow and less uniform with advancing age, while subchondral sclerosis appeared to be wider and less uniform in the elderly. Osteophytes were present even in younger patients and their prevalence increased with advancing age. Ankylosis and erosions were rare findings, observed only after the fifth decade of life. A higher prevalence of asymmetric non-uniform SJ space, ill-defined, non-uniform, extensive subchondral sclerosis and ankylosis was observed in women, obese and multiparous mothers than the age matched men, normal weighted individuals and non-multiparous women, respectively.
Conventional pelvic CT can provide valuable information concerning the SJ, when reviewed on bone window settings. The CT appearance of the SJ is closely related to patients age, gender, BMI and, in women, parity. Knowledge of the spectrum of radiological findings observed in the normal population may be useful when interpreting examinations of patients with SJ disease.
A technique that provides a craniocaudal axial view of the sacroiliac joint is described. This technique gives information about the ventral aspect of the sacroiliac joint, particularly at the level of the pelvic brim. It can demonstrate extraarticular ventral ankylosis of the joint, which is not visible or only suspected on anteroposterior films. In osteitis condensans ilii, it shows the thickness of the involved iliac bone. It is very useful for the accurate localization of paraarticular changes.
A radiological study of the sacroiliac joints was undertaken in 54 patients (32 males, 22 females) with vertebral ankylosing hyperostosis (VAH) and in 46 control patients (24 males, 22 females) matched for age and sex. The ages ranged from 38 to 90 years. The radiographs were taken in anteroposterior, oblique, and craniocaudal projections. The films were read for cranial, ventral, and caudal capsular ossifications, for ventral and caudal osteophytes, and for bone sclerosis. Cranial and/or ventral capsular ossifications were found in 28 (87.5%) males with VAH and in 4 (16.6%) control males (p less than 0.0005), but only in 2 females with VAH and no control female. Sacroiliac capsular ossifications in males with VaH are frequent from the onset, but complete bridging of the joint is not reached before the sixth decade. Women, either VAH or control, have more sacroiliac osteophytes than men. There were 11 out of 22 control women with osteophytes versus 4 out of 24 men (p less than 0.025). The incidence of osteophytes does not seem to increase with age after 50 years. Our findings support the idea of VAH being a distinct entity and not a major form of osteophytosis.