Apparent diffusion coefficient values in Modic changes - interobserver reproducibility and relation to Modic type

Magnhild H Dagestad; Nils Vetti; Per M Kristoffersen; John-Anker Zwart; Kjersti Storheim; Gunnstein Bakland; Jens I Brox; Lars Grøvle; Gunn H Marchand; Erling Andersen; Jörg Assmus; Ansgar Espeland

doi:10.1186/s12891-022-05610-4

Apparent diffusion coefficient values in Modic changes - interobserver reproducibility and relation to Modic type

BMC Musculoskelet Disord. 2022 Jul 22;23(1):695. doi: 10.1186/s12891-022-05610-4.

Authors

Magnhild H Dagestad^{1

2}, Nils Vetti^{3

4}, Per M Kristoffersen^{3

4}, John-Anker Zwart^{5

6}, Kjersti Storheim^{5

7}, Gunnstein Bakland⁸, Jens I Brox^{6

9}, Lars Grøvle¹⁰, Gunn H Marchand^{11

12}, Erling Andersen¹³, Jörg Assmus¹⁴, Ansgar Espeland^{3

4}

Affiliations

¹ Department of Radiology, Haukeland University Hospital, Jonas Liesvei 65, 5021, Bergen, Norway. magnhild.hammersland.dagestad@helse-bergen.no.
² Department of Clinical Medicine, University of Bergen, P.O. Box 7804, 5020, Bergen, Norway. magnhild.hammersland.dagestad@helse-bergen.no.
³ Department of Radiology, Haukeland University Hospital, Jonas Liesvei 65, 5021, Bergen, Norway.
⁴ Department of Clinical Medicine, University of Bergen, P.O. Box 7804, 5020, Bergen, Norway.
⁵ Research and Communication Unit for Musculoskeletal Health (FORMI), Division of Neuroscience, Oslo University Hospital HF, Ulleval, Bygg 37b, P.O. Box 4956, Nydalen, 0424, Oslo, Norway.
⁶ Faculty of Medicine, University of Oslo, P.O. Box 1072 Blindern, 0316, Oslo, Norway.
⁷ Faculty of Health Science, OsloMet - Oslo Metropolitan University, P.O. Box 4, St. Olavs plass, 0130, Oslo, Norway.
⁸ Department of Rheumatology, University Hospital of North Norway, P.O. Box 100, 9038, Tromsø, Norway.
⁹ Department of Physical Medicine and Rehabilitation, Oslo University Hospital HF, P.O. Box 4956 Nydalen, 0424, Oslo, Norway.
¹⁰ Department of Rheumatology, Østfold Hospital Trust, P.O. Box 300, 1714 Grålum, Moss, Norway.
¹¹ Departement of Physical Medicine and Rehabilitation, St. Olavs Hospital, Trondheim University Hospital, P.O. Box 3250 Torgarden, 7006, Trondheim, Norway.
¹² Departement of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU), 7491, Trondheim, Norway.
¹³ Department of Clinical Engineering, Haukeland University Hospital, P.O. Box 1400, 5021, Bergen, Norway.
¹⁴ Centre for Clinical Research, Haukeland University Hospital, Jonas Liesvei 65, 5021, Bergen, Norway.

Abstract

Background: Modic Changes (MCs) in the vertebral bone marrow were related to back pain in some studies but have uncertain clinical relevance. Diffusion weighted MRI with apparent diffusion coefficient (ADC)-measurements can add information on bone marrow lesions. However, few have studied ADC measurements in MCs. Further studies require reproducible and valid measurements. We expect valid ADC values to be higher in MC type 1 (oedema type) vs type 3 (sclerotic type) vs type 2 (fatty type). Accordingly, the purpose of this study was to evaluate ADC values in MCs for interobserver reproducibility and relation to MC type.

Methods: We used ADC maps (b 50, 400, 800 s/mm²) from 1.5 T lumbar spine MRI of 90 chronic low back pain patients with MCs in the AIM (Antibiotics In Modic changes)-study. Two radiologists independently measured ADC in fixed-sized regions of interests. Variables were MC-ADC (ADC in MC), MC-ADC% (0% = vertebral body, 100% = cerebrospinal fluid) and MC-ADC-ratio (MC-ADC divided by vertebral body ADC). We calculated mean difference between observers ± limits of agreement (LoA) at separate endplates. The relation between ADC variables and MC type was assessed using linear mixed-effects models and by calculating the area under the receiver operating characteristic curve (AUC).

Results: The 90 patients (mean age 44 years; 54 women) had 224 MCs Th12-S1 comprising type 1 (n = 111), type 2 (n = 91) and type 3 MC groups (n = 22). All ADC variables had higher predicted mean for type 1 vs 3 vs 2 (p < 0.001 to 0.02): MC-ADC (10^{- 6} mm²/s) 1201/796/576, MC-ADC% 36/21/14, and MC-ADC-ratio 5.9/4.2/3.1. MC-ADC and MC-ADC% had moderate to high ability to discriminate between the MC type groups (AUC 0.73-0.91). MC-ADC-ratio had low to moderate ability (AUC 0.67-0.85). At L4-S1, widest/narrowest LoA were for MC-ADC 20 ± 407/12 ± 254, MC-ADC% 1.6 ± 18.8/1.4 ± 10.4, and MC-ADC-ratio 0.3 ± 4.3/0.2 ± 3.9. Difference between observers > 50% of their mean value was less frequent for MC-ADC (9% of MCs) vs MC-ADC% and MC-ADC-ratio (17-20%).

Conclusions: The MC-ADC variable (highest mean ADC in the MC) had best interobserver reproducibility, discriminated between MC type groups, and may be used in further research. ADC values differed between MC types as expected from previously reported MC histology.

Keywords: Adults; Imaging sequences; MR-imaging; Observer performance; Skeletal-axial; Spine.

MeSH terms

Adult
Bone Diseases*
Diffusion Magnetic Resonance Imaging
Female
Humans
Low Back Pain* / diagnostic imaging
Magnetic Resonance Imaging
ROC Curve
Reproducibility of Results