Influence of field strength, coil type and image resolution on assessment of synovitis by unenhanced MRI--a comparison with contrast-enhanced MRI

TY - JOUR

T1 - Influence of field strength, coil type and image resolution on assessment of synovitis by unenhanced MRI--a comparison with contrast-enhanced MRI

AU - Eshed, Iris

AU - Krabbe, Simon

AU - Østergaard, Mikkel

AU - Bøyesen, Pernille

AU - Møller, Jakob M

AU - Therkildsen, Flemming

AU - Madsen, Ole Rintek

AU - Axelsen, Mette

AU - Pedersen, Susanne Juhl

PY - 2015/3/12

Y1 - 2015/3/12

N2 - OBJECTIVES: To explore if the reliability of synovitis assessment by unenhanced MRI is influenced by different MRI field-strengths, coil types and image resolutions in RA patients.METHODS: Forty-one RA patients and 12 healthy controls underwent hand MRI (wrist and 2(nd)--5(th) metacarpophalangeal joints) at 4 different field-strengths (0.23 T/0.6 T/1.5 T/3.0 T) on the same day. Seven protocols using a STIR sequence with different field-strengths, coils (flex coils/dedicated phased-array extremity coils) and resolution were applied and scored blindly for synovitis (OMERACT-RAMRIS method). A 1.5 T post-contrast T1-weighted sequence was used as gold standard reference.RESULTS: Fair-good agreement (ICC=0.38--0.72) between the standard reference and the different STIR protocols (best agreement with extremity coil and small voxel size at 1.5 T). The accuracy for presence/absence of synovitis was very high per person (0.80--1.0), and moderate-high per joint (0.63--0.85), whereas exact agreements on scores were moderate (0.50--0.66). The intrareader agreement (15 patients and 3 controls) on presence/absence of synovitis was very high (0.87--1.0).CONCLUSIONS: Unenhanced MRI using STIR sequence is only moderately reliable for assessing hand synovitis in RA, when contrast-enhanced MRI is considered the gold standard reference. Contrast injection, field strength and coil type influence synovitis assessment, and should be considered before performing MRI in clinical trials and practice.KEY POINTS: • STIR is only moderately reliable for synovitis assessment, compared with post-contrast-T1-w. • Contrast injection, field strength, and coil type influence synovitis assessment. • Contrast injection is recommended for reliable and reproducible hand synovitis assessment.

AB - OBJECTIVES: To explore if the reliability of synovitis assessment by unenhanced MRI is influenced by different MRI field-strengths, coil types and image resolutions in RA patients.METHODS: Forty-one RA patients and 12 healthy controls underwent hand MRI (wrist and 2(nd)--5(th) metacarpophalangeal joints) at 4 different field-strengths (0.23 T/0.6 T/1.5 T/3.0 T) on the same day. Seven protocols using a STIR sequence with different field-strengths, coils (flex coils/dedicated phased-array extremity coils) and resolution were applied and scored blindly for synovitis (OMERACT-RAMRIS method). A 1.5 T post-contrast T1-weighted sequence was used as gold standard reference.RESULTS: Fair-good agreement (ICC=0.38--0.72) between the standard reference and the different STIR protocols (best agreement with extremity coil and small voxel size at 1.5 T). The accuracy for presence/absence of synovitis was very high per person (0.80--1.0), and moderate-high per joint (0.63--0.85), whereas exact agreements on scores were moderate (0.50--0.66). The intrareader agreement (15 patients and 3 controls) on presence/absence of synovitis was very high (0.87--1.0).CONCLUSIONS: Unenhanced MRI using STIR sequence is only moderately reliable for assessing hand synovitis in RA, when contrast-enhanced MRI is considered the gold standard reference. Contrast injection, field strength and coil type influence synovitis assessment, and should be considered before performing MRI in clinical trials and practice.KEY POINTS: • STIR is only moderately reliable for synovitis assessment, compared with post-contrast-T1-w. • Contrast injection, field strength, and coil type influence synovitis assessment. • Contrast injection is recommended for reliable and reproducible hand synovitis assessment.

KW - Adolescent

KW - Aged

KW - Aged, 80 and over

KW - Contrast Media

KW - Female

KW - Humans

KW - Image Enhancement

KW - Magnetic Resonance Imaging

KW - Male

KW - Middle Aged

KW - Reproducibility of Results

KW - Synovitis

KW - Young Adult

U2 - 10.1007/s00330-014-3470-9

DO - 10.1007/s00330-014-3470-9

M3 - Journal article

C2 - 25537977

SN - 0938-7994

VL - 25

SP - 1059

EP - 1067

JO - European Radiology

JF - European Radiology

IS - 4

ER -