CC BY-NC-ND 4.0 · Indian J Radiol Imaging 2023; 33(02): 173-182
DOI: 10.1055/s-0042-1760285
Original Article

Qualitative and Quantitative Evaluation of Morpho-Metabolic Changes in Bone Cartilage Complex of Knee Joint in Osteoarthritis Using Simultaneous 18F-NaF PET/MRI—A Pilot Study

Amarnath Jena
1   Department of Molecular Imaging and Nuclear Medicine, Indraprastha Apollo Hospital, New Delhi, India
Nidhi Goyal
2   Department of Radiodiagnosis and Imaging, Indraprastha Apollo Hospitals, New Delhi, India
Prerana Rana
1   Department of Molecular Imaging and Nuclear Medicine, Indraprastha Apollo Hospital, New Delhi, India
3   Apollo Hospitals Education and Research Foundation, Indraprastha Apollo Hospitals, New Delhi, India
Sangeeta Taneja
1   Department of Molecular Imaging and Nuclear Medicine, Indraprastha Apollo Hospital, New Delhi, India
Abhishek Vaish
4   Department of Orthopaedics and Joint Replacement Surgery, Indraprastha Apollo Hospitals, New Delhi, India
Rajesh Botchu
5   Department of Musculoskeletal Radiology, Royal Orthopedic Hospital, Birmingham, United Kingdom
Raju Vaishya
4   Department of Orthopaedics and Joint Replacement Surgery, Indraprastha Apollo Hospitals, New Delhi, India
› Author Affiliations
Funding Apollo Hospital Educational Research Foundation (AHERF), Wallace, Gardens, Chennai, Tamil Nadu, is a not-for-profit foundation of India recognized by the Department of Scientific and Industrial Research (DSIR) as a Scientific and Industrial Research Organisation (SIRO). AHERF had funded this work under the Faculty Development Program (FDP).


Background Articular cartilage (AC) loss and deterioration, as well as bone remodeling, are all symptoms of osteoarthritis (OA). As a result, an ideal imaging technique for researching OA is required, which must be sensitive to both soft tissue and bone health.

Objective The aim of this study was to assess the potential of simultaneous 18F sodium fluoride (18F-NaF) positron emission tomography/magnetic resonance imaging (PET/MRI) to identify as well as classify osseous metabolic abnormalities in knee OA and to see if degenerative changes in the cartilage and bone on MRI might be correlated with subchondral 18F-NaF uptake on PET.

Methods Sixteen (32 knees) volunteers with no past history of knee injury, with or without pain, were enrolled for the research from January to July 2021. The images of both knees were taken utilizing an molecular magnetic resonance (mMR) body matrix coil on a simultaneous PET/MRI biograph mMR. The acquisition was conducted after 45 minutes of intravenous infusion of 18F-NaF 185–370 MBq (5–10 mCi) over one PET bed for 40 minutes, while MRI sequences were performed simultaneously.

Results All pathologies showed significantly higher maximum standardized uptake value (SUVmax) than the background. Thirty-four subchondral magic spots were identified on 18F-NaF PET without any structural alteration on MRI. Bone marrow lesions (BMLs) and osteophytes with higher MRI osteoarthritis knee score (MOAKS) score showed higher 18F-NaF uptake (grade1˂grade2˂grade3). BMLs had corresponding AC degeneration. There was discordance between grade 1 osteophytes (86.6%), sclerosis (53.7%) and grade 1 BML in cruciate ligament insertion site (91.66%); they did not have high uptake of 18F-NaF. In case of cartilage, there was significant difference between AC grades and average subchondral SUVmax and T2* relaxometry (grade0˂grade1˂grade2˂grade3˂grade4). BMLs are much more metabolically active than other pathologies, while sclerosis is the least. We also found that the subchondral uptake was statistically increased in the areas of pathology:

Conclusion 18F-NaF PET/MRI was able to detect knee abnormalities unseen on MRI alone and simultaneously assessed metabolic and structural markers of knee OA across multiple tissues in the joint. Thus, it is a promising tool for detection of early metabolic changes in OA.

Supplementary Material

Publication History

Article published online:
06 January 2023

© 2023. Indian Radiological Association. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (

Thieme Medical and Scientific Publishers Pvt. Ltd.
A-12, 2nd Floor, Sector 2, Noida-201301 UP, India

  • References

  • 1 Azad CS, Singh AK, Pandey P. et al. Osteoarthritis in India: an epidemiologic aspect. Int J Recent Sci Res 2017; 8 (10) 20918-20922
  • 2 World Health Organization. “Chronic Rheumatic Conditions.” Chronic diseases and health promotion. 2012 . Accessed December 17, 2022 at:
  • 3 Teitel AD, Zieve D. MedlinePlud Medical Encycolpedia. National Institutes of Health. “Osteoarthritis.”. Accessed December 17, 2022 at:
  • 4 Wirth W, Buck R, Nevitt M. et al; OAI Investigators. MRI-based extended ordered values more efficiently differentiate cartilage loss in knees with and without joint space narrowing than region-specific approaches using MRI or radiography–data from the OA initiative. Osteoarthritis Cartilage 2011; 19 (06) 689-699
  • 5 Binks DA, Hodgson RJ, Ries ME. et al. Quantitative parametric MRI of articular cartilage: a review of progress and open challenges. Br J Radiol 2013; 86 (1023): 20120163 DOI: 10.1259/bjr.20120 163.
  • 6 Williams A, Qian Y, Golla S, Chu CR. UTE-T2 ∗ mapping detects sub-clinical meniscus injury after anterior cruciate ligament tear. Osteoarthritis Cartilage 2012; 20 (06) 486-494
  • 7 Ling W, Regatte RR, Navon G, Jerschow A. Assessment of glycosaminoglycan concentration in vivo by chemical exchange-dependent saturation transfer (gagCEST). Proc Natl Acad Sci 2008; 105 (07) 2266-2270
  • 8 Madelin G, Babb J, Xia D. et al. Articular cartilage: evaluation with fluid-suppressed 7.0-T sodium MR imaging in subjects with and subjects without osteoarthritis. Radiology 2013; 268 (02) 481-491
  • 9 Watkins L, MacKay J, Haddock B. et al. Assessment of quantitative [18F]Sodium fluoride PET measures of knee subchondral bone perfusion and mineralization in osteoarthritic and healthy subjects. Osteoarthritis Cartilage 2021; 29 (06) 849-858
  • 10 Burr DB, Gallant MA. Bone remodelling in osteoarthritis. Nat Rev Rheumatol 2012; 8 (11) 665-673
  • 11 Blau M, Nagler W, Bender MA. Fluorine-18: a new isotope for bone scanning. J Nucl Med 1962; 3: 332-334
  • 12 Jadvar H, Desai B, Conti PS. Sodium 18F-fluoride PET/CT of bone, joint, and other disorders. Semin Nucl Med 2015; 45 (01) 58-65
  • 13 Kogan F, Broski SM, Yoon D, Gold GE. Applications of PET-MRI in musculoskeletal disease. J Magn Reson Imaging 2018; 48 (01) 27-47
  • 14 Kohn MD, Sassoon AA, Fernando ND. Classifications in brief: Kellgren-Lawrence classification of osteoarthritis. Clin Orthop Relat Res 2016; 474 (08) 1886-1893
  • 15 Grant FD, Fahey FH, Packard AB, Davis RT, Alavi A, Treves ST. Skeletal PET with 18F-fluoride: applying new technology to an old tracer. J Nucl Med 2008; 49 (01) 68-78
  • 16 Segall G, Delbeke D, Stabin MG. et al; SNM. SNM practice guideline for sodium 18F-fluoride PET/CT bone scans 1.0. J Nucl Med 2010; 51 (11) 1813-1820
  • 17 Hunter DJ, Guermazi A, Lo GH. et al. Evolution of semi-quantitative whole joint assessment of knee OA: MOAKS (MRI Osteoarthritis Knee Score). Osteoarthritis Cartilage 2011; 19 (08) 990-1002
  • 18 Paunipagar BK, Rasalkar D. Imaging of articular cartilage. Indian J Radiol Imaging 2014; 24 (03) 237-248
  • 19 Torigian DA, Zaidi H, Kwee TC. et al. PET/MR imaging: technical aspects and potential clinical applications. Radiology 2013; 267 (01) 26-44
  • 20 Kogan F, Fan AP, McWalter EJ, Oei EHG, Quon A, Gold GE. PET/MRI of metabolic activity in osteoarthritis: a feasibility study. J Magn Reson Imaging 2017; 45 (06) 1736-1745
  • 21 Felson DT, Chaisson CE, Hill CL. et al. The association of bone marrow lesions with pain in knee osteoarthritis. Ann Intern Med 2001; 134 (07) 541-549
  • 22 Link TM, Steinbach LS, Ghosh S. et al. Osteoarthritis: MR imaging findings in different stages of disease and correlation with clinical findings. Radiology 2003; 226 (02) 373-381
  • 23 Felson DT, McLaughlin S, Goggins J. et al. Bone marrow edema and its relation to progression of knee osteoarthritis. Ann Intern Med 2003; 139 (5 Pt 1): 330-336
  • 24 Roemer FW, Guermazi A, Javaid MK. et al; MOST Study investigators. Change in MRI-detected subchondral bone marrow lesions is associated with cartilage loss: the MOST study. A longitudinal multicentre study of knee osteoarthritis. Ann Rheum Dis 2009; 68 (09) 1461-1465
  • 25 Muratovic D, Cicuttini F, Wluka A. et al. Bone marrow lesions detected by specific combination of MRI sequences are associated with severity of osteochondral degeneration. Arthritis Res Ther 2016; 18: 54
  • 26 Lee D, Hong KT, Lim TS. et al. Alterations in articular cartilage T2 star relaxation time following mechanical disorders: in vivo canine supraspinatus tendon resection models. BMC Musculoskelet Disord 2020; 21 (01) 424
  • 27 Mankin HJ, Dorfman H, Lippiello L, Zarins A. Biochemical and metabolic abnormalities in articular cartilage from osteo-arthritic human hips. II. Correlation of morphology with biochemical and metabolic data. J Bone Joint Surg Am 1971; 53 (03) 523-537
  • 28 Williams A, Qian Y, Bear D, Chu CR. Assessing degeneration of human articular cartilage with ultra-short echo time (UTE) T2* mapping. Osteoarthritis Cartilage 2010; 18 (04) 539-546
  • 29 Guermazi A, Alizai H, Crema MD, Trattnig S, Regatte RR, Roemer FW. Compositional MRI techniques for evaluation of cartilage degeneration in osteoarthritis. Osteoarthritis Cartilage 2015; 23 (10) 1639-1653
  • 30 Hesper T, Hosalkar HS, Bittersohl D. et al. T2* mapping for articular cartilage assessment: principles, current applications, and future prospects. Skeletal Radiol 2014; 43 (10) 1429-1445
  • 31 Aznar MC, Sersar R, Saabye J. et al. Whole-body PET/MRI: the effect of bone attenuation during MR-based attenuation correction in oncology imaging. Eur J Radiol 2014; 83 (07) 1177-1183
  • 32 Jena A, Taneja S, Rana P. et al. Emerging role of integrated PET-MRI in osteoarthritis. Skeletal Radiol 2021; 50 (12) 2349-2363
  • 33 Antony B, Singh A. Imaging and biochemical markers for osteoarthritis. Diagnostics (Basel) 2021; 11 (07) 1205 DOI: 10.3390/diagnostics11071205.