With the general approach for dGEMRIC imaging in vivo validated, it is important to understand the characteristics of the scans in clinical applications. For these clinical studies, the "dGEMRIC index" (T1Gd) was taken as T1 after penetration of GdDTPA into the cartilage, approximately 1-2 hours after intravenous administration.

Through a series of case studies, we demonstrated a dynamic range of T1Gd index seen across individuals: The T1Gd index of the cartilage of the knees of a professional dancer is in the high-range, with a global mean of over 500 ms (Fig. 1a).T1Gd indices in the range of 400 to 500 ms were in the mid-range of the cases studied (Fig.1b). Lower end T1Gd indices, under 400 ms, have been seen in cartilage in individuals with moderate to severe osteoarthritis (Fig. 1c), with focal areas as low as 250 ms.

gag topFigure 1a gag side
gag middleFigure 1b
gag bottomFigure 1c

Other cases demonstrate more generalized differences across compartments. In Figure 2A, a case shows distinctly lower values of T1Gd laterally in an individual with an ACL tear. Substantial variations can also be seen within a compartment; Figure 2B illustrates the lateral compartment in an individual with medial osteoarthritis. While the lateral compartment has relatively intact cartilage anatomically, there are clearly areas of focal low T1Gd values 35% lower than surrounding cartilage.

dgemic fig 2aFigure 2a
dgemic fig 2bFigure 2b

T1Gd was also monitored in 10 volunteers taking glucosamine/chondroitin sulfate supplements (CosaminDS; Nutramax Laboratories, Edgewood, MD). Four volunteers who are professional dancers taking supplements showed no change after 6 months. Increases of 13 and 19 % were seen in two volunteers taking supplements while recovering from arthroscopic surgery. Three other volunteers recovering from arthroscopic surgery did not change significantly. One volunteer with a history of knee injuries (patellar fracture and menisectomy) decreased 9%, and had reported that he had stopped running while taking the supplements. These results are summarized in Figure 3.

dgemic fig 3Figure 3

For more details, see:

Williams A, Gillis A, McKenzie C, Po B, Sharma L, Micheli L, McKeon B, Burstein D. Glycosaminoglycan distribution in cartilage as determined by delayed gadiolinium enhanced MRI of cartilage: Potential clinical applications. Amer J. Roentgenology, in press.

Carticel Implants

With the general approach for dGEMRIC imaging in vivo validated, it is important to understand the characteristics of the scans in clinical applications. For these clinical studies, the "dGEMRIC index" (T1Gd) was taken as T1 after penetration of GdDTPA into the cartilage, approximately 1-2 hours after intravenous administration.

Through a series of case studies, we demonstrated a dynamic range of T1Gd index seen across individuals: The T1Gd index of the cartilage of the knees of a professional dancer is in the high-range, with a global mean of over 500 ms (Fig. 1a).T1Gd indices in the range of 400 to 500 ms were in the mid-range of the cases studied (Fig.1b). Lower end T1Gd indices, under 400 ms, have been seen in cartilage in individuals with moderate to severe osteoarthritis (Fig. 1c), with focal areas as low as 250 ms.

gag topFigure 1a gag side
gag middleFigure 1b
gag bottomFigure 1c

Other cases demonstrate more generalized differences across compartments. In Figure 2A, a case shows distinctly lower values of T1Gd laterally in an individual with an ACL tear. Substantial variations can also be seen within a compartment; Figure 2B illustrates the lateral compartment in an individual with medial osteoarthritis. While the lateral compartment has relatively intact cartilage anatomically, there are clearly areas of focal low T1Gd values 35% lower than surrounding cartilage.

dgemic fig 2aFigure 2a
dgemic fig 2bFigure 2b

T1Gd was also monitored in 10 volunteers taking glucosamine/chondroitin sulfate supplements (CosaminDS; Nutramax Laboratories, Edgewood, MD). Four volunteers who are professional dancers taking supplements showed no change after 6 months. Increases of 13 and 19 % were seen in two volunteers taking supplements while recovering from arthroscopic surgery. Three other volunteers recovering from arthroscopic surgery did not change significantly. One volunteer with a history of knee injuries (patellar fracture and menisectomy) decreased 9%, and had reported that he had stopped running while taking the supplements. These results are summarized in Figure 3.

dgemic fig 3Figure 3

For more details, see:

Williams A, Gillis A, McKenzie C, Po B, Sharma L, Micheli L, McKeon B, Burstein D. Glycosaminoglycan distribution in cartilage as determined by delayed gadiolinium enhanced MRI of cartilage: Potential clinical applications. Amer J. Roentgenology, in press.

Carticel Implants

There is increasing in interest in utilizing tissue implants to repair focal cartilage lesions. In one application of Carticel implants (Genzyme Biosurgery, Cambridge, MA), a patient's cartilage cells are harvested from one area of the joint, grown in culture, and then reimplanted in the lesion area. dGEMRIC provides the opportunity to monitor the accumulation of GAG in the implant area. In a pilot study, implants of 6 months or less had lower GAG than the surrounding tissue, while implants of 12 months or greater (with one exception) had comparable GAG levels to the surrounding tissue (Figures 1 and 2).

invivoapp12 months post-op invivoapp21.5 years post-op invivovalidgrad
Figure 1: dGEMRIC image of a Carticel implant 2 months post-op vs. another one 1.5 years post-op.

invivovalid 3Figure 2: If a value of 75% of the control cartilage is considered to be a graft which has accumulated GAG at levels comparable to the control, at times of 12 months or greater, 4 out of 5 grafts contain GAG at comparable levels as control,as compared to none of those less than 12 months.

For more information, see:

Gillis A, Bashir A, McKeon B, Scheller A, Gray ML, Burstein D. Magnetic resonance imaging of relative glycosaminoglycan distribution in patients with autologous chondrocyte transplants. Investigative Radiol, 2001; 36: 743-748.

Hip dysplasia

Osteoarthritis (OA) is thought to result from a failure of chondrocytes within the joint to maintain the balance between the synthesis and degradation of the cartilage matrix. One cause of such imbalance is the abnormal mechanics seen in developmental dysplasia of the hip. The progression of OA in untreated severe hip dysplasia is accepted. We have applied dGEMRIC to study patients with hip dysplasia, and compared the results with standard radiographic measures.

In these studies, we have found that the dGEMRIC index (T1), as a measure of tissue GAG, was significantly lower (i.e. lower GAG) in symptomatic hips than in the contralateral less symptomatic (or asymptomatic) hips (Figure 1). Furthermore, the dGEMRIC index correlated with the clinical pain score, while radiographic measures did not show such a correlation (Figure 2). Finally, the dGEMRIC index was significantly different in the patient groups with different levels of severity of dysplasia, while the radiographic measure of joint space narrowing did not differentiate these groups (Figure 3).

invivoapp4 invivoapp5 invivovalidgrad
Figure 1: dGEMRIC image of the asymptomatic (left) and symptomatic (right) hip in the same individual. The symptomatic hip has lower GAG concentration.

invivoapp6Figure 2: T1 ( dGEMRIC) correlates with the WOMAC pain score. There is no correlation between the standard joint space narrowing parameter and the pain score.


dysplasiadysplasia 2Figures 3.

For more information, please refer to:

Kim Y-J, Jaramillo D, Millis MB, Gray ML, Burstein D. Assessment of early osteoarthritis in hip dysplasia using delayed Gadolinium Enhanced MRI of Cartilage. J Bone Joint Surgery, 2003; 85-A: 1987-1992.