Pre-contrast T1 and cartilage thickness as confounding factors in dGEMRIC when evaluating human cartilage adaptation to physical activity

Abstract Background The dGEMRIC (delayed Gadolinium-Enhanced MRI of Cartilage) technique has been used in numerous studies for quantitative in vivo evaluation of the relative glycosaminoglycan (GAG) content in cartilage. The purpose of this study was to determine the influence of pre-contrast T1 and cartilage thickness when assessing knee joint cartilage quality with dGEMRIC. Methods Cartilage thickness and T1 relaxation time were measured in the central part of the femoral condyles before and two hours after intravenous Gd-DTPA2− administration in 17 healthy volunteers from a previous study divided into two groups: 9 sedentary volunteers and 8 exercising elite runners. Results were analyzed in superficial and a deep weight-bearing, as well as in non-weight-bearing regions of interest. Results In the medial compartment, the cartilage was thicker in the exercising group, in weight-bearing and non-weight-bearing segments. In most of the segments, the T1 pre-contrast value was longer in the exercising group compared to the sedentary group. Both groups had a longer pre-contrast T1 in the superficial cartilage than in the deep cartilage. In the superficial cartilage, the gadolinium concentration was independent of cartilage thickness. In contrast, there was a linear correlation between the gadolinium concentration and cartilage thickness in the deep cartilage region. Conclusion Cartilage pre-contrast T1 and thickness are sources of error in dGEMRIC that should be considered when analysing bulk values. Our results indicate that differences in cartilage structure due to exercise and weight-bearing may be less pronounced than previously demonstrated.

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Effects of ACL graft placement on in vivo knee function and cartilage thickness distributions

Journal of Orthopaedic Research® ◽

10.1002/jor.23541 ◽

2017 ◽

Vol 35 (6) ◽

pp. 1160-1170 ◽

Cited By ~ 13

Author(s):

Louis E. DeFrate

Keyword(s):

Cartilage Thickness ◽

Knee Function ◽

Graft Placement ◽

Acl Graft ◽

And Cartilage

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Comparison of Different Approaches for Measuring Tibial Cartilage Thickness

Journal of Integrative Bioinformatics ◽

10.1515/jib-2017-0015 ◽

2017 ◽

Vol 14 (2) ◽

Cited By ~ 6

Author(s):

Jennifer Maier ◽

Marianne Black ◽

Serena Bonaretti ◽

Bastian Bier ◽

Bjoern Eskofier ◽

...

Keyword(s):

Nearest Neighbor ◽

Distance Measure ◽

Thickness Distribution ◽

Weight Bearing ◽

Correlation Coefficients ◽

Cartilage Thickness ◽

Tibial Cartilage ◽

Normal Vectors ◽

Field Lines

AbstractOsteoarthritis is a degenerative disease affecting bones and cartilage especially in the human knee. In this context, cartilage thickness is an indicator for knee cartilage health. Thickness measurements are performed on medical images acquired in-vivo. Currently, there is no standard method agreed upon that defines a distance measure in articular cartilage. In this work, we present a comparison of different methods commonly used in literature. These methods are based on nearest neighbors, surface normal vectors, local thickness and potential field lines. All approaches were applied to manual segmentations of tibia and lateral and medial tibial cartilage performed by experienced raters. The underlying data were contrast agent-enhanced cone-beam C-arm CT reconstructions of one healthy subject’s knee. The subject was scanned three times, once in supine position and two times in a standing weight-bearing position. A comparison of the resulting thickness maps shows similar distributions and high correlation coefficients between the approaches above 0.90. The nearest neighbor method results on average in the lowest cartilage thickness values, while the local thickness approach assigns the highest values. We showed that the different methods agree in their thickness distribution. The results will be used for a future evaluation of cartilage change under weight-bearing conditions.

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Single- vs. double-dose gadolinium contrast in delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) in knee osteoarthritis: is dose reduction possible on 3-T MRI?

Acta Radiologica ◽

10.1177/0284185118796694 ◽

2018 ◽

Vol 60 (6) ◽

pp. 749-754

Author(s):

Stine Hangaard ◽

Jesper Sörensson Gade ◽

Philip Hansen ◽

Janus Damm Nybing ◽

Henrik Gudbergsen ◽

...

Keyword(s):

Relaxation Time ◽

Single Dose ◽

Knee Osteoarthritis ◽

Weight Bearing ◽

Relaxation Times ◽

Lateral Compartment ◽

Double Dose ◽

Gadolinium Contrast ◽

T1 Relaxation Time ◽

T1 Relaxation

Background Reduction in gadolinium (Gd) contrast agents is wanted due to the uncertainty of the potential side effects. Purpose To investigate whether it is possible to reduce the contrast dose from conventional double dose to single dose when increasing the field strength from 1.5-T to 3-T for separating early cartilage degeneration from healthy cartilage, assessed by delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC). Material and Methods Nine patients with knee osteoarthritis (OA), Kellgren–Lawrence grade (KLG) 1–4, were recruited from an ongoing weight loss cohort study. dGEMRIC was performed at 3-T using single (0.1 mmoI/kg) and double (0.2 mmoI/kg) doses of intravenous (i.v.) Gd-DTPA2-. Regions of interest (ROls) were drawn around the posterior weight-bearing femoral knee cartilage in lateral and medial compartments. In five medial compartments ROIs could not be drawn due to severe degeneration of cartilage. T1-relaxation times were compared to previously published values from 1.5-T and to non-contrast values from 3-T. Results Mean dGEMRIC T1-relaxation time in the lateral compartment was 769 ms for single dose vs. 561 ms for double dose ( P < 0.0001); and 685 ms for single dose vs. 454 ms for double dose ( P = 0.004) in the medial compartment. Conclusion We found a dose-response relationship between single and double doses of Gd-DTPA2- using 3-T in knee OA patients, similar to the findings at 1.5-T. Compared to the T1-relaxation time at 3-T without contrast (1240 ms), this further separation between OA and normal cartilage indicates that “single dose” dGEMRIC could be sufficient for cartilage health assessment at 3-T.

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A general model to calculate the spin-lattice (T1) relaxation time of blood, accounting for haematocrit, oxygen saturation and magnetic field strength

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x15605856 ◽

2015 ◽

Vol 36 (2) ◽

pp. 370-374 ◽

Cited By ~ 26

Author(s):

Patrick W Hales ◽

Fenella J Kirkham ◽

Christopher A Clark

Keyword(s):

Magnetic Field ◽

Relaxation Time ◽

Oxygen Saturation ◽

In Vivo Studies ◽

T1 Relaxation Time ◽

Spin Lattice ◽

T1 Relaxation ◽

Improved Accuracy

Many MRI techniques require prior knowledge of the T1-relaxation time of blood ( T1 bl). An assumed/fixed value is often used; however, T1 bl is sensitive to magnetic field ( B0), haematocrit ( Hct), and oxygen saturation ( Y). We aimed to combine data from previous in vitro measurements into a mathematical model, to estimate T1 bl as a function of B0, Hct, and Y. The model was shown to predict T1 bl from in vivo studies with a good accuracy (±87 ms). This model allows for improved estimation of T1 bl between 1.5–7.0 T while accounting for variations in Hct and Y, leading to improved accuracy of MRI-derived perfusion measurements.

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In vivo evaluation of the bond strength of adhesive 4-META/MMA-TBB bone cement under weight-bearing conditions

Journal of Biomedical Materials Research ◽

10.1002/1097-4636(200010)52:1<128::aid-jbm16>3.0.co;2-l ◽

2000 ◽

Vol 52 (1) ◽

pp. 128-134 ◽

Cited By ~ 15

Author(s):

Tomoko Sakai ◽

Sadao Morita ◽

Ken-ichi Shinomiya ◽

Akihiko Watanabe ◽

Nobuo Nakabayashi ◽

...

Keyword(s):

Bond Strength ◽

Bone Cement ◽

Weight Bearing ◽

In Vivo Evaluation

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Segmented interlocking nail: An in vivo evaluation of a novel humeral osteotomy fixation device in a caprine model

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.3415/vcot-11-04-0060 ◽

2012 ◽

Vol 25 (01) ◽

pp. 28-35 ◽

Cited By ~ 3

Author(s):

R. D. Montgomery ◽

M. A. Edmondson ◽

T. J. Stephens

Keyword(s):

Weight Bearing ◽

Mature Female ◽

Bone Union ◽

Research Model ◽

Fixation Device ◽

Insertion Technique ◽

In Vivo Evaluation ◽

Interlocking Nail ◽

Early Return

SummaryObjectives: To describe a novel humeral fixation device, the insertion technique, healing of humeral osteotomies, and clinical outcomes in a caprine model over a six month period.Methods: Fourteen mature female Boer/Nubian cross goats with a mean body weight of 50.7 kg were implanted with a proprietary segmented interlocking nail (SILN) in both humeri. Each goat had one humerus randomly selected for mid-diaphyseal osteotomy.Results: Immediately after surgery all but one goat was able to stand, although none of the goats were weight bearing on the osteotomy limb. During the six month study, clinical lameness was always associated with the osteotomy limb. One month after surgery, lameness for twelve of the goats was grade 2/5 or better. At three months, 11 of the 14 did not exhibit any signs of lameness. On radio-graphic images, notable malalignment of the osteotomy was observed, although all osteotomies went to bone union.Clinical significance: The results of this study suggest that despite misalignment, the SILN maintained adequate osteotomy fixation to achieve bone union in the research model studied, with reduced morbidity and early return to function with bilateral implantation. The SILN used in this study allowed intramedullary fixation of humeral diaphyseal osteotomies with a limited and safe surgical approach.

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