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 Table of Contents  
ORIGINAL ARTICLE
Year : 2016  |  Volume : 11  |  Issue : 4  |  Page : 186-191

Ultrasound and magnetic resonance imaging correlation of the wrist and metacarpophalangeal joints in fifty consecutive patients of rheumatoid arthritis


1 Department of Radiodiagnosis, Jawaharlal Nehru Hospital and Research Centre, Bhilai, Chhattisgarh, India
2 Department of Medicine, Jawaharlal Nehru Hospital and Research Centre, Bhilai, Chhattisgarh, India
3 Department of Gastroenterology, Jawaharlal Nehru Hospital and Research Centre, Bhilai, Chhattisgarh, India

Date of Web Publication8-Nov-2016

Correspondence Address:
Dr. Pratibha Issar
Department of Radiodiagnosis, Joint DMHS, Jawaharlal Nehru Hospital and Research Centre, Bhilai - 490 006, Chhattisgarh
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0973-3698.192683

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  Abstract 

Background: Gray-scale ultrasound and Power Doppler ultrasound (GSUS, PDUS) and contrast Magnetic Resonance Imaging (MRI) are the imaging modalities to detect the disease in this early stage of rheumatoid arthritis (RA). This study was conducted to observe the advantages and disadvantages of USG and MRI of wrist and metacarpophalangeal joints in patients with rheumatoid arthritis.
Methods: Clinically diagnosed cases of RA were included. GSUS-PDUS and high field (1.5T) MRI with contrast were used by two assessors. The evaluation and scoring was done using the RAMRIS score. Other assessed parameters included Joint space narrowing, GSUS bone erosions, Gray scale USG synovial hypertrophy, MRI tenosynovitis and tenosynovitis on GSUS.
Results: Total 50 patients (44 female, 6 male; age 18-76 years) with 100 joints and 400 Metacarpophalangeal joints (2nd to 5th) including 2300 bone areas were evaluated. GSUS, PDUS evaluation was equal to contrast MRI evaluation in detecting joint space narrowing, effusion, flexor tenosynovitis (except for FPL tendon), extensor tenosynovitis. Whereas synovial thickening was better picked up in GSUS, PDUS than on contrast MRI. Contrast MRI picked up more cases of bone erosions, triangular fibro cartilage lesions and active synovitis as compared to GSUS, PDUS. Bone marrow edema which indicates active ostitis could only be directly detected on contrast MRI.
Conclusions: GSUS, PDUS can be used as radiological investigative modality for the diagnosis of cases of early rheumatoid arthritis specially for synovial thickening, joint effusion, flexor and extensor tenosynovitis.

Keywords: Bone edema, bone erosion, magnetic resonance imaging, rheumatoid arthritis, tenosynovitis, ultrasonography


How to cite this article:
Issar P, Nadiger VM, Hiran S, Issar SK. Ultrasound and magnetic resonance imaging correlation of the wrist and metacarpophalangeal joints in fifty consecutive patients of rheumatoid arthritis. Indian J Rheumatol 2016;11:186-91

How to cite this URL:
Issar P, Nadiger VM, Hiran S, Issar SK. Ultrasound and magnetic resonance imaging correlation of the wrist and metacarpophalangeal joints in fifty consecutive patients of rheumatoid arthritis. Indian J Rheumatol [serial online] 2016 [cited 2019 Sep 17];11:186-91. Available from: http://www.indianjrheumatol.com/text.asp?2016/11/4/186/192683


  Introduction Top


Rheumatoid arthritis (RA) initially involves the synovium of the joints leading to synovial thickening, synovial hyperemia, and pannus formation; later on, bone erosions and destruction and deformity of the joints will occur.

Synovitis is the initial presentation of the disease, which can be better treated, controlled, and prevented from progression if it is diagnosed in early stage.

Ultrasonography (USG) and magnetic resonance imaging (MRI) are the imaging modalities of choice to detect the disease in this early stage as X-ray, computed tomography scan, and scintigraphy are less accurate and have some disadvantages such as radiation and lack of wide availability.

Both USG and MRI lack the problem of radiation exposure but have certain advantages and limitations in diagnosing the RA accurately. As USG is cost-effective, widely available method where dynamic, interactive scanning of joint is possible and multiple joints can be scanned at a time, but it is limited by nonvisualization of the deeper structures and bone marrow edema (BME) and is operator-dependent. MRI can detect all structures in and around the joint but has the disadvantages such as increased cost, artifacts due to motion of the patient, and exposure to contrast gadolinium.[1],[2]

The objective of this study was to compare modalities, Gray-scale ultrasound and Power Doppler ultrasound (GSUS, PDUS) with contrast MRI.


  Materials and Methods Top


This study was carried out in the Department of Radiodiagnosis, JLN Hospital and Research Center, Bhilai, Chhattisgarh. Modalities used were USG-GE Logiq P5 premium and Philips high definition (HD) 11, with 5–12 MHz linear-array HD probe and MRI-1.5 Tesla GE SIGNA EXCITE MR system using 8-channel cardiac coil.

Patient selection

Fifty clinically diagnosed cases of RA of both sexes and all age groups attending medicine/rheumatology/orthopedics clinics were included from August 2014 to January 2016 according to modified ACR criteria-1987.[3]

For ultrasound examination, the patients were made to sit in a chair on the left side of the examination couch and kept both wrists and hands on a pillow over the examination couch for US in prone and supine positions. The time required to scan a patient completely was 15–20 min.[3],[4]

For MRI, the patients were positioned in the prone position with both forearms extended and internally rotated at elbow and hands mildly flexed at the wrist. Those who has claustrophobia and contraindications to MRI were excluded. Plain and post contrast sequences were taken in the axial and coronal planes.[5] Post contrast sequences are taken after MRI contrast gadolinium 10 ml is injected through pressure injector followed by 20 ml of normal saline, and after a delay of 20 s, images are acquired. The time required to scan a patient completely with contrast was approximately 30–35 minutes using various sequences [Table 1].
Table 1: Details of magnetic resonance sequences

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The images were evaluated and scored by two observers, one with 4 years of experience in musculoskeletal radiology (VN) and another with 10 years of experience in musculoskeletal radiology (PI).

Scoring was done using RAMRIS score as recommended by OMERACT. With OMERACT-RAMRIS score, synovitis scored from 0 to 3 according to severity, BME scored - 0–3, bone erosions scored 0–10 according to the extent of the bone involved.[6]

Joint space narrowing was scored in both MRI and GSUS and was scored as 0 - normal, 1 - focal narrowing, 2 - <50% narrowing, 3 - >50% narrowing, and 4 - ankylosis in accordance with Sokka study.[7]

GSUS bone erosions are graded as follows: No erosion – 0; erosions with diameter <2 mm − Grade 1; with 2–4 mm − Grade 2; and >4 mm − Grade 3, in accordance with Hammer et al.[8]

Gray-scale USG synovial hypertrophy was assessed by quantitative measurement of the thickness of synovium as Grade 1 = synovitis between 0.5 and 2 mm, Grade 2 = synovitis between 2 and 3 mm, Grade 3 = more than 3 mm, in accordance with Vlad et al.[9]

MRI tenosynovitis graded as Grade 0 (normal): No peritendinous effusion or synovial proliferation with enhancement, Grade 1: 2 mm peritendinous effusion and/or synovial proliferation with enhancement, Grade 2: more than 2 and less than 5 mm peritendinous effusion and/or synovial proliferation with enhancement Grade 3: more than 5 mm peritendinous effusion and/or synovial proliferation with enhancement, in accordance with Haavardsholm et al.[10]

Tenosynovitis on GSUS semiquantitatively scored from 0 to 3 with Grade 0 being normal and Grade 3-severely affected depending on the peritendinous sheath thickening and fluid collection, in accordance with Harman et al.[11]

Sensitivity, specificity, positive predictive value, and negative predictive value of USG were compared with that of MRI in the identification of findings in RA in the wrist and MCP joints with their scoring as mentioned in RAMRIS score. Chi-square test analysis was done to study the correlation between ultrasound and MRI findings in RA of the wrist and MCP joints, and P value was calculated if <0.06 is considered as statistically significant.

MedCalc statistical software version 15.11.4 (MedCalc Software bvba, Ostend, Belgium) was used for analyses. This study was cleared by the Institutional ethics committee.


  Results Top


With fifty patients, a total of 100 wrist joints and 400 MCP joints (2nd to 5th) including 2300 bone areas were evaluated by GSUS, PDUS, and contrast MRI. The evaluated patients were in the age group of 18–76 years with 18 years (female) being the youngest and 76 years (female) being the eldest patient with mean age being 45.8 years, and most of the patients in this study were in 51–60 years, followed by 31–40 years group [Table 2]. Females were predominant patients of RA in our study with a male to female ratio of 1:7.3. All of the patients were diagnosed as RA according to the ACR 1987 criteria.
Table 2: Age and sex distribution of patients

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Serum rheumatoid factor was positive in 70% (n-35) and serum Anti-citrullinated protein antibodies in 54% (n-27). Most of the patients were having symptoms since 11–15 years - 38% (n-19). The minimum duration of symptoms was 6 months, and the maximum was 20 years. The right hand and wrist were predominantly involved (70%) as compared to the left hand and wrist.

Joint space narrowing

Joint space narrowing in RA was maximum at radiocarpal joints, followed by intercarpal, distal radioulnar, and MCP joints [Table 3].
Table 3: Joint space narrowing score: Ultrasonography, magnetic resonance imaging

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Joint effusion

It was evaluated by directly visualizing fluid in the joint cavity on USG as hypoechoic to the anechoic collection and on MRI as a hyperintense area on T2 fat sat and short-tau inversion recovery (STIR) sequence images. Joint effusion was mainly seen in radiocarpal joints (RCJs), followed by intercarpal joints (ICJs), distal radioulnar joints (DRUJs), and MCP joints.

Synovium

Synovium appears on USG as the hypoechoic covering around the joint which can be differentiated from effusion by its nondisplaceability on pressure. In MRI it appears as enhancing layer on post contrast T1-weighted images and hyperintensity on T2 and STIR images, and a thickness of 0.5 mm is considered normal [Figure 1] and [Figure 2].
Figure 1: Ultrasonography shows distal radioulnar joint synovium thickened with increased vascularity

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Figure 2: Post contrast axial T1 image showing synovial thickening and enhancement in the distal radioulnar joint, radiocarpal joint, flexor and extensor tenosynovitis

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On studying the synovial thickening score, it was found that on USG, the maximum score was achieved by RCJ (158), followed by DRUJ (125), ICJ (102), and 5th MCP joints (58), respectively, whereas on MRI maximum score was assigned to RCJ (116) followed by ICJ (72), DRUJ (63), and 5th MCP joints (36), respectively. MRI scores were lesser as compared to USG scores [Table 4].
Table 4: Synovial thickening score

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In this study, synovitis diagnosed as synovial vascularity with signal on PDUS and synovial enhancement on contrast MRI. On comparing the power Doppler signal on synovium with enhancement of synovium on contrast MRI to diagnose the active synovitis, it was found that the sensitivity and specificity of PDUS over contrast MRI were low in all the joints examined and sensitivity ranged from 0% to 68%, specificity ranged from 0% to 100%, positive and negative predictive values ranged from 0 to 100. P values on Chi-square tests were <0.06 in most of the joints except left MCP joints which were statistically significant which indicates that USG and MRI have a significant difference in diagnosing the synovial vascularity with MRI being superior.

Tenosynovitis

P values of Chi-square test for flexor tenosynovitis were >0.06 which is statistically insignificant suggesting that the USG and MRI were comparable with each other in the diagnosis of flexor tenosynovitis in terms of sensitivity and specificity except for flexor carpi radialis (FCR) tendon with P = 0.0001 suggesting that there is a significant difference between USG and MRI in diagnosing the tenosynovitis of FCR tendon with MRI being superior. In RA, flexor digitorum superficialis, flexor digitorum profundus, flexor pollicis longus, flexor carpi ulnaris, and FCR are the tendon sheaths which are commonly involved in order in terms of number and severity. P values of Chi-square test for extensor tenosynovitis in all of the extensor tendons were > 0.06 which is statistically insignificant suggesting that the USG and MRI were comparable with each other in the diagnosis of extensor tenosynovitis. In RA, ECU is most commonly and severity involved, followed by extensor digitorum, extensor pollicis longus, extensor carpi radialis longus, extensor carpi radialis brevis, and extensor digiti minimi (EDM) tendons in order [Figure 3].
Figure 3: Ultrasonography shows extensor digitorum tenosynovitis

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Bone erosion

On USG and MRI, bone erosion scores were diagnosed as focal cortical discontinuity at least in 2 perpendicular planes [Figure 4] and [Figure 5]. MRI was found to be superior as compared to GSUS, PDUS in diagnosing and scoring the bone erosions. Moreover, in our cases, bone erosions were commonly found in the distal end of ulna [Table 5].
Figure 4: Magnetic resonance imaging Coronal T1 image showing erosions in distal end radius, ulna, and multiple carpal bones

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Figure 5: Ultrasonography shows erosions in lunate and triquetral

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Table 5: Bone erosion score: Ultrasonography, magnetic resonance imaging

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Bone marrow edema

BME is the sign of active osteitis seen in inflammatory arthritis that can be diagnosed only on MRI as hyperintensity in the bones on STIR images [Figure 6]. BME is most commonly seen in the DEU followed by lunate, distal end of radius, scaphoid, hamate, distal part MCP joint, and 1st metacarpal (MC) base bones, and these bones are involved in severity in terms of BME score in the same order.
Figure 6: Coronal short-tau inversion recovery sequence showing edema in bilateral lunate

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Triangular fibrocartilage complex

Triangular fibrocartilage complex (TFCC) degeneration in fifty patients with 100 TFCC of both wrist joints studied – results showed that degeneration was found in 3% (n-3) on USG (bulky and hypoechoic), 35% (n-35) on MRI (as abnormal hyperintensity on STIR images) which appeared to be statistically significant with P = 0.0001 suggesting that the sensitivity of USG in diagnosing TFCC lesions was less, and MRI is better suited to diagnose the TFCC lesions.


  Discussion Top


The earliest imaging abnormalities in RA are synovial thickening with vascularity, effusion, and BME which could be evaluated with GSUS, PDUS, and contrast MRI.

In fifty patients, we evaluated 100 wrist and 400 MCP joints (2nd–5th), including 2300 bones, in the age group of 18–76 years. Most of our patients had involvement predominantly of the right hand (n-35) followed by bilaterally equal involvement (n-12), few had left-hand involvement (n-3). The maximum number of patients were in 40–60 years; female:male ratio in our study was 7.3:1.

In our study, predominantly the joint space was narrowed in RCJs (81%) followed by intercarpal (62%), MCP (68%), and DRUJs (62%). USG and MRI were found to be relatively equally sensitive and specific in all joints evaluated. Joint space narrowing is seen in the advanced stage of the disease rather in an early stage; in this study, we got the severe diseases in relatively elderly patients and those with long duration of the disease.[12]

GSUS, PDUS, and contrast MRI were equally sensitive in detecting the joint effusion except for ICJs where MRI was found superior.[13] GSUS, PDUS could detect more synovial thickening as compared to contrast MRI.[14]

The high concordance between Doppler USG and contrast-enhanced MRI for the detection of synovitis in RA wrist and finger joints was found. USG has a high level of agreement with MRI in assessments of synovitis.[15]

Flexor tenosynovitis is the most powerful predictor of early RA. In our study, we compared flexor and extensor tenosynovitis on GSUS, PDUS, and contrast MRI. Flexor tenosynovitis was found in 30% on GSUS, PDUS, and 29% on contrast MRI. Extensor tenosynovitis was found in 28.7% on GSUS, PDUS and 28.3% on contrast MRI suggesting the flexor tendons involved are more as compared to extensor tendons.[16] One EDM tendon rupture was found associated with severe disease in the distal radioulnar and radiocarpal joints in a 45-year-old patient having RA for 5 years.

BME was seen in most of the bones of the wrist and MCP joints except 3rd MC base, 3rd proximal and distal MCP joint, and 4th proximal MCP joint area. The maximum number of bones involved are - distal end of ulna (n-94), followed by lunate (n-88) and distal end of radius (n-71). Around 26.7% of bones showed edema in our series with the mean edema score of 0.31.[17]

Bone erosions: In our study, the distal end of ulna (US-92% MR-100%) was the most common site for bone erosions and the site most severely involved followed by distal end radius (US-72% MR-94%), lunate (US-29% MR-95%), scaphoid (US-40% MR-87%), and distal 5th MCP joint (US-29% MR-90%). MRI (44.8%) could detect and score the bone erosions better than USG (14%). Our study showed bone erosions in 14% of US case and 44.8% in MRI, which is statistically significant with P = 0.0001 suggesting that sensitivity of USG is less than MRI.[18] Pisiform is the only bone that did not have any erosion either on MRI or USG.

In this study, the correlation was found between bone erosion and BME score on GSUS PDUS and MRI. As the bone erosions score in either GSUS–PDUS or MRI increases -the BME scores also increase for particular bones, hence by assessing the bone erosion score on GSUS-PDUS we can predict the possibility of BME on MRI in a particular bone.[19],[20]

Triangular fibrocartilage complex lesions are common in the RA as the ulnar collateral ligament becomes lax due to erosions of the distal end of the ulna. Degeneration of triangular fibrocartilage complex was seen in 3% on USG, 35% on MRI, suggesting MRI to be the investigation of choice in identifying the triangular fibrocartilage complex lesions.[21]


  Conclusion Top


GSUS–PDUS can be used for diagnosing joint space narrowing, joint effusion, and synovial thickening, whereas MRI is a better modality for detecting bone erosions, BME, and triangular fibrocartilage complex lesions. By assessing the Bone erosions on GSUS-PDUS the possibility of BME on MRI may be predicted in a particular bone. Tenosynovitis could be detected on either MRI or GSUS–PDUS with similar sensitivity.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
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    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]


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[Pubmed] | [DOI]



 

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