Patients with Type 2 Diabetes Exhibit a More Mineralized Deep Cartilage Layer Compared with Nondiabetic Controls: A Pilot Study

Abstract

Objective To assess differences in biochemical composition of the deep cartilage layer in subjects with type 2 diabetes mellitus (T2DM) and nondiabetic controls using UTE (ultra-short echo time) T2* mapping and to investigate the association of vascular health and UTE T2* measurements. Design Ten subjects with T2DM matched for age, sex, and body mass index with 10 nondiabetic controls. A 3D UTE sequence with 6 echo times was acquired using 3T magnetic resonance imaging of the knee. For UTE T2* analysis, the deep cartilage layer was segmented and analyzed in 5 compartments (patella, medial, and lateral femur and tibia). The ankle brachial index (ABI) was obtained in all subjects. Linear regression analyses were used to assess associations of T2DM and UTE T2* relaxation times and the associations of ABI measurements and UTE measurements. Results Compared with nondiabetic controls, T2DM subjects had significantly lower mean T2*-UTE in the patella (mean difference 4.87 ms; 95% confidence interval [CI] 1.09-8.65; P = 0.015), the lateral tibia (mean difference 2.26 ms; 95% CI 0.06-4.45; P = 0.045), and the lateral femur (mean difference 4.96 ms; 95% CI 0.19-9.73; P = 0.043). Independent of diabetic status, subjects with higher ABI values, indicating better vascular health, had higher T2*-UTE of the patella (coefficient 15.2; 95% CI 3.3-21.4; P = 0.017), the medial tibia (coefficient 9.8; 95% CI 1.0-18.6; P = 0.031), and the lateral femur (coefficient 18.8; 95% CI 3.3-34.3; P = 0.021). Conclusions T2*-UTE measurements of the deep cartilage layer were consistently lower in subjects with T2DM and in subjects with impaired vascular health, likely indicating increased mineralization of this layer.

Feasibility of ultrashort echo time (UTE) T2* cartilage mapping in the hip: a pilot study

“…More recently, alteration of UTE T2* values attributable to increased mineralization were found in the knee of patients with type 2 diabetes and impaired vascular health (28). Our results demonstrate that the technique can be similarly applied in the hip.…”

“…Our segmentation of the deep cartilage layer was done on the fitted data and likely included not only the calcified deep layer that is identified on the first echo images but also voxels outside of this layer. Although prior work has isolated segmentation to the calcified deep layer (28), others have included larger ROIs for the deep layer that encompass half the full cartilage layer (11). Finally, we applied a mono-exponential model to generate T2* fits whereas some recent studies have proposed using bi-exponential fits for articular cartilage mapping (29).…”

Ultrashort Echo Time Magnetic Resonance Imaging Techniques: Met and Unmet Needs in Musculoskeletal Imaging

“…0.1-0.2 mm) and curved, T2* derived from regular UTE with variable TEs is likely subject to significant errors due to the partial volume effect. 109 The adiabatic IR-based UTE sequences provide efficient long-T2 suppression and thus much more accurate T2* mapping. 23 The second challenge is related to fat contamination and off-resonance artifacts.…”

Trajectory correction based on the gradient impulse response function improves high‐resolution UTE imaging of the musculoskeletal system

“…[7][8][9][10] Many of the above MSK tissues are associated with thin structures and therefore require high-resolution imaging. For instance, cartilage in the knee measures between 2 and 7 mm thick and has been shown to include short-T 2 components with T 2 relaxation times in the order of 1 to 4 ms. [11][12][13] Separately, the mean thickness of cortical bone in the lumbar spine is found to be on the order of 0.3 mm, with short T 2 relaxation times of 0.1 to 1 ms. 7,[14][15][16] UTE imaging is usually implemented along non-Cartesian trajectories to achieve data acquisition at UTEs. Data are acquired as soon as possible after the RF excitation and during the ramping up of the readout gradient.…”

“…Many of the above MSK tissues are associated with thin structures and therefore require high‐resolution imaging. For instance, cartilage in the knee measures between 2 and 7 mm thick and has been shown to include short‐T 2 components with T 2 relaxation times in the order of 1 to 4 ms 11‐13 . Separately, the mean thickness of cortical bone in the lumbar spine is found to be on the order of 0.3 mm, with short T 2 relaxation times of 0.1 to 1 ms 7,14‐16 …”