Significant Differences In T2 Values Research Articles

Differences in running biomechanics and tibiotalar cartilage T2 relaxation time between runners with and without asymptomatic tibial sesamoid bone marrow edema – clinical case series

ABSTRACT The impact of asymptomatic bone marrow edema (BME) in sesamoids on running biomechanics remains largely unknown, but exploring this relationship could aid early detection of forefoot-related injuries with cost-effective modalities. This study aimed to compare the running biomechanics of runners with asymptomatic BME in the tibial sesamoids with that of healthy controls. Four runners with asymptomatic BME in tibial sesamoids and four healthy runners participated. Lower extremity joint kinetics and kinematics were assessed along with plantar pressure while running at a self-selected speed. The T2 relaxation time of the tibiotalar cartilage was measured using MRI-derived T2 maps. Compared to the non-injured group, the injured group exhibited significantly lower plantar pressure under the hallux (p = 0.001), increased peak ankle rotation angles (p = 0.025), reduced ankle power generation (p = 0.049), and increased knee extension torque (p = 0.015). No significant differences in T2 values of the tibiotalar cartilage were observed. It appears that runners with asymptomatic BME adapted their running strategies by modifying their ankle biomechanics and reducing plantar pressure, even in the absence of pain. While the precise implications of these biomechanical alterations warrant further investigation, this study provides valuable insights into the relationship between asymptomatic BME and running biomechanics.

Clear Twin Block Versus Traditional Twin Block: a Clinical Electromyographic Comparison

Background: Functional appliances such as twin blocks are widely used to treat skeletal Cl II malocclusions. Myofunctional effects are one of the critical features of these appliances. The present study aimed to investigate the muscular effects of clear and traditional twin blocks. Methods: In this randomized clinical trial, 60 skeletal Cl II div 1 patient were randomly divided into two groups: clear twin block (CTB) and traditional twin block (TTB). Electromyographic (EMG) evaluation of masseter, anterior temporalis, orbicularis oris, and mentalis muscles was carried out during deglutition, rest, whistling, and forced occlusion before insertion (T1) and six months (T2) after insertion of the appliance. Data were analyzed using independent t-test, paired t-test, and Wilcoxon’s signed rank at the 0.05 significance level. Results: There were no significant differences in T2 values between the groups (P>0.05). The intragroup comparisons showed a significant change from T1 to T2 in the CTB group for the clenching of the masseter muscle and in the TTB group for swallowing and rest position of the anterior temporalis muscle and swallowing of the masseter muscle (P<0.05). Conclusion: Both CTB and TTB changed the muscular activity of circumoral muscles. No significant difference was found when the post-treatment muscular activity of the two groups was compared.

Variation in cartilage T2 and T2* mapping of the wrist: a comparison between 3- and 7-T MRI

BackgroundTo analyze regional variations in T2 and T2* relaxation times in wrist joint cartilage and the triangular fibrocartilage complex (TFCC) at 3 and 7 T and to compare values between field strengths.MethodsTwenty-five healthy controls and 25 patients with chronic wrist pain were examined at 3 and 7 T on the same day using T2- and T2*-weighted sequences. Six different regions of interest (ROIs) were evaluated for cartilage and 3 ROIs were evaluated at the TFCC based on manual segmentation. Paired t-tests were used to compare T2 and T2* values between field strengths and between different ROIs. Spearman’s rank correlation was calculated to assess correlations between T2 and T2* time values at 3 and 7 T.ResultsT2 and T2* time values of the cartilage differed significantly between 3 and 7 T for all ROIs (p ≤ 0.045), with one exception: at the distal lunate, no significant differences in T2 values were observed between field strengths. T2* values differed significantly between 3 and 7 T for all ROIs of the TFCC (p ≤ 0.001). Spearman’s rank correlation between 3 and 7 T ranged from 0.03 to 0.62 for T2 values and from 0.01 to 0.48 for T2* values. T2 and T2* values for cartilage varied across anatomic locations in healthy controls at both 3 and 7 T.ConclusionQuantitative results of T2 and T2* mapping at the wrist differ between field strengths, with poor correlation between 3 and 7 T. Local variations in cartilage T2 and T2* values are observed in healthy individuals.Relevance statementT2 and T2* mapping are feasible for compositional imaging of the TFCC and the cartilage at the wrist at both 3 and 7 T, but the clinical interpretation remains challenging due to differences between field strengths and variations between anatomic locations.Key points•Field strength and anatomic locations influence T2 and T2* values at the wrist.•T2 and T2* values have a poor correlation between 3 and 7 T.•Local reference values are needed for each anatomic location for reliable interpretation.Graphical

Study of T2 mapping in quantifying and discriminating uterine lesions under different magnetic field strengths: 1.5 T vs. 3.0 T

BackgroundMRI is the best imaging tool for the evaluation of uterine tumors, but conventional MRI diagnosis results rely on radiologists and contrast agents (if needed). As a new objective, reproducible and contrast-agent free quantification technique, T2 mapping has been applied to a number of diseases, but studies on the evaluation of uterine lesions and the influence of magnetic field strength are few. Therefore, the aim of this study was to systematically investigate and compare the performance of T2 mapping as a nonenhanced imaging tool in discriminating common uterine lesions between 1.5 T and 3.0 T MRI systems.MethodsA total of 50 healthy subjects and 126 patients with suspected uterine lesions were enrolled in our study, and routine uterine MRI sequences with additional T2 mapping sequences were performed. T2 maps were calculated by monoexponential fitting using a custom code in MATLAB. T2 values of normal uterine structures in the healthy group and lesions (benign: adenomyosis, myoma, endometrial polyps; malignant: cervical cancer, endometrial carcinoma) in the patient group were collected. The differences in T2 values between 1.5 T MRI and 3.0 T MRI in any normal structure or lesion were compared. The comparison of T2 values between benign and malignant lesions was also performed under each magnetic field strength, and the diagnostic efficacies of the T2 value obtained through receiver operating characteristic (ROC) analysis were compared between 1.5 T and 3.0 T.ResultsThe mean T2 value of any normal uterine structure or uterine lesion under 3.0 T MRI was significantly lower than that under 1.5 T MRI (p < 0.05). There were significant differences in T2 values between each lesion subgroup under both 1.5 T and 3.0 T MRI. Moreover, the T2 values of benign lesions (71.1 ± 22.0 ms at 1.5 T and 63.4 ± 19.1 ms at 3.0 T) were also significantly lower than those of malignant lesions (101.1 ± 4.5 ms at 1.5 T and 93.5 ± 5.1 ms at 3.0 T) under both field strengths. In the aspect of differentiating benign from malignant lesions, the area under the curve of the T2 value under 3.0 T (0.94) was significantly higher than that under 1.5 T MRI (0.90) (p = 0.02).ConclusionT2 mapping can be a potential tool for quantifying common uterine lesions, and it has better performance in distinguishing benign from malignant lesions under 3.0 T MRI.

T2 MRI at 3T of cartilage and menisci in patients with hyperuricemia: initial findings.

To compare and evaluate T2 values of compartmental femorotibial cartilage and subregional menisci in patients with hyperuricemia at 3T. Thirty-two subjects were included in this study and subdivided into two subgroups: 15 healthy controls (3 females, 12 males; mean age = 45.3 ± 10.9years), 17 patients with hyperuricemia (2 females, 15 males; mean age = 44.4 ± 12.7years). All subjects were assessed on a 3T MR scanner using an 8-channel phased-array knee coil (transmit-receive). Wilcoxon rank sum test and analysis of covariance (ANCOVA) were performed to determine whether there were any statistically significant differences in T2 values of compartmental femorotibial cartilage and subregional menisci between the two subgroups. Lateral tibial cartilage (48.6 ± 3.5ms) in healthy subgroup had significantly lower (p < 0.05) T2 values than all subcompartments of femorotibial cartilage in hyperuricemia subgroup. Medial tibial cartilage (56.5 ± 4.3ms) in hyperuricemia subgroup had significantly higher (p < 0.05) T2 values than all subcompartments of femorotibial cartilage except medial tibial cartilage in healthy subgroup. Medial anterior horn of meniscus (39.4 ± 2.9ms) in healthy subgroup had significantly lower (p < 0.05) T2 values than all subregional menisci except both medial anterior horn and medial body segment of meniscus in hyperuricemia subgroup. T2 values in certain compartmental femorotibial cartilage and subregional menisci in patients with hyperuricemia are evidently and abnormally heightened compared with those in healthy subjects, to which special attention should be paid when diagnosing and treating the patients with hyperuricemia in the clinical setting. The LT cartilage had significantly lower T2 values (48.6 ± 3.5ms) in healthy subgroup compared to all compartmental femorotibial cartilage in cohort with HU. MF cartilage had significantly lower T2 values (51.6 ± 2.9ms) in healthy subgroup compared to both LF (54.4 ± 4.1ms) and MT (56.5 ± 4.3ms) in cohort with HU. MT cartilage had significantly higher T2 values (56.5 ± 4.3ms) in cohort with HU subgroup compared to LF (52.5 ± 3.0ms) in healthy subgroup. T2 mapping may be promising and potential sensitive discriminator of understanding and examining the early compositional and structural change in proteoglycan-collagen matrix of human femorotibial cartilage in patients with hyperuricemia.

Cartilage Matrix Changes in Hindfoot Joints in Chronic Ankle Instability Patients After Anatomic Repair Using T2-Mapping: Initial Experience With 3-Year Follow-Up.

Anatomic repair is widely accepted as the primary surgical treatment for chronic lateral ankle instability (CLAI). T2-mapping is a powerful tool for quantitative assessment of biochemical changes in cartilage matrix. To longitudinally evaluate cartilage matrix changes in the hindfoot joints of CLAI patients before and after anatomic repair by using T2-mapping with magnetic resonance imaging (MRI). Prospective. Thirty-two CLAI patients (males/females=20/12) and 21 healthy controls (males/females=13/7). 3 T; sagittal multi-echo spin-echo technique (T2-mapping), coronal, sagittal, and axial spin-echo PD-FS, and sagittal T1WI sequences. MRI examinations were performed in CLAI patients at baseline (prior to surgery) and 3 years after anatomic repair and in healthy controls. On T2-maps, the hindfoot joints were segmented into 16 cartilage subregions. The T2 value of each subregion was measured. All patients were evaluated with the American Orthopedic Foot and Ankle Society (AOFAS) scale at baseline and after surgery. Analysis of variance (ANOVA) and Student's t-test were used. The differences corresponding to P < 0.05 were considered statistically significant. At baseline, the T2 values in most cartilage subregions of talar dome and medial posterior subtalar joint (pSTJ) were higher in CLAI patients than in healthy controls. After surgery, only the T2 value of anteriomedial talar dome decreased from that at baseline (31.11 ± 3.88 msec vs. 34.27 ± 5.30 msec). The T2 values of other subregions with elevated T2 values remained higher than healthy controls. There were no significant differences in T2 values in the midtarsal joints between CLAI patients and healthy controls (P=0.262, 0.104, 0.169, 0.103). Postoperatively, the patients' AOFAS scores improved significantly from 67.81 to 89.13. CLAI patients exhibited elevated T2 values in most subregions of talar dome and medial pSTJ. After anatomic repair, although the patients exhibited good clinical outcomes, the elevated T2 values could not be fully recovered. 2 TECHNICAL EFFICACY STAGE: 4.

T2 mapping of the peritumoral infiltration zone of glioblastoma and anaplastic astrocytoma.

PurposeTo characterise peritumoral zones in glioblastoma and anaplastic astrocytoma evaluating T2 values using T2 mapping sequences.Materials and methodsIn this study, 41 patients with histopathologically confirmed World Health Organization high grade gliomas and preoperative magnetic resonance imaging examinations were retrospectively identified and enrolled. High grade gliomas were differentiated: (a) by grade, glioblastoma versus anaplastic astrocytoma; and (b) by isocitrate dehydrogenase mutational state, mutated versus wildtype. T2 map relaxation times were assessed from the tumour centre to peritumoral zones by means of a region of interest and calculated pixelwise by using a fit model.ResultsSignificant differences between T2 values evaluated from the tumour centre to the peritumoral zone were found between glioblastoma and anaplastic astrocytoma, showing a higher decrease in signal intensity (T2 value) from tumour centre to periphery for glioblastoma (P = 0.0049 – fit-model: glioblastoma –25.02± 19.89 (–54–10); anaplastic astrocytoma –5.57±22.94 (–51–47)). Similar results were found when the cohort was subdivided by their isocitrate dehydrogenase profile, showing an increased drawdown from tumour centre to periphery for wildtype in comparison to mutated isocitrate dehydrogenase (P = 0.0430 – fit model: isocitrate dehydrogenase wildtype –10.35±16.20 (–51) – 0; isocitrate dehydrogenase mutated 12.14±21.24 (–15–47)). A strong statistical proof for both subgroup analyses (P = 0.9987 – glioblastoma R2 0.93±0.08; anaplastic astrocytoma R2 0.94±0.15) was found.ConclusionPeritumoral T2 mapping relaxation time tissue behaviour of glioblastoma differs from anaplastic astrocytoma. Significant differences in T2 values, using T2 mapping relaxation time, were found between glioblastoma and anaplastic astrocytoma, capturing the tumour centre to the peritumoral zone. A similar curve progression from tumour centre to peritumoral zone was found for isocitrate dehydrogenase wildtype high grade gliomas in comparison to isocitrate dehydrogenase mutated high grade gliomas. This finding is in accordance with the biologically more aggressive behaviour of isocitrate dehydrogenase wildtype in comparison to isocitrate dehydrogenase mutated high grade gliomas. These results emphasize the potential of mapping techniques to reflect the tissue composition of high grade gliomas.

Significant Association between the T2 Values of Vertebral Cartilage Endplates and Pfirrmann Grading.

ObjectiveThe T2 value of lumbar cartilage endplates was measured using the T2 mapping imaging technique, aiming to explore the correlation between the T2 value and Pfirrmann grading of intervertebral discs.MethodsA total of 130 patients with lumbar spine MR examination due to persistent low back pain were enrolled, including 71 men and 59 women (age: 21–63 years). Lumbar Modic changes and Schmorl nodules were recognized by conventional T1WI and T2WI images in 49 patients, and these patients were excluded from the study. A total of 81 patients were enrolled in this study, including 45 men (45.16 ± 12.20 years) and 36 women (43.33 ± 11.27 years). Pfirrmann (Pm) grading of each lumbar disc was performed based on conventional T2WI median sagittal images and the position of cartilage endplates (CEP) was determined by IDEAL‐SPGR images. Meanwhile, the T2 mapping technique was used to obtain T2 values of cartilage endplates. The T2 values of CEP corresponding to different Pm grade discs were compared, and the correlation between the T2 value and the Pm grade of intervertebral discs was analyzed.ResultsThe T2 values of cephalic and caudal CEP of L1–2 in Pm grades I–II, Pm grades III, and Pm grades IV–V were 61.96 ± 5.89 ms, 54.45 ± 3.29 ms, 42.47 ± 3.69 ms and 64.35 ± 5.93 ms, 55.28 ± 3.97 ms, 44.75 ± 2.12 ms, respectively. For cephalic and caudal CEP of L2–3, the T2 values in Pm grades I–II, Pm grades III, and Pm grades IV–V were 62.96 ± 6.93 ms, 55.19 ± 4.02 ms, 48.67 ± 4.56 ms and 65.51 ± 6.49 ms, 57.16 ± 5.55 ms, 52.05 ± 4.20 ms, respectively. The T2 values of cephalic and caudal CEP from L3–4 to L5–S1 in Pm grades I–II, Pm grades III, and Pm grades IV–V were (63.72 ± 5.76 ms, 53.96 ± 6.52 ms, 48.05 ± 5.00 ms), (65.46 ± 6.37 ms, 55.70 ± 7.50 ms, 48.10 ± 3.27 ms); (66.34 ± 7.68 ms, 56.76 ± 9.48 ms, 47.80 ± 4.33 ms), (64.44 ± 4.65 ms, 59.30 ± 8.80 ms, 47.30 ± 5.78 ms), (65.32 ± 5.11 ms, 55.33 ± 6.65 ms, 48.18 ± 5.37 ms), and (63.47 ± 4.92 ms, 50.32 ± 8.86 ms, 44.77 ± 4.69 ms), respectively. There were significant differences in T2 values of cartilage endplates between the Pm grades I–II, III, and IV–V of intervertebral discs (P = 0.000). T2 values corresponding to Pm I–II grades were higher than those in Pm III grade, while T2 values in Pm grades IV–V were lowest. The T2 value of the L4–5, L5–S1 segment endplates was highly correlated with the Pm grades (r = −0.711, −0.721, −0.796, −0.745; P = 0.000) and that of L1–2, L2–3 endplates were moderately correlated (r = −0.542, −0.562, −0.637, −0.612; P = 0.000).ConclusionThe T2 values of cartilage endplates revealed varying degrees of degeneration of intervertebral discs, and more severe degeneration corresponded to lower T2 values. Measurement of changes in the T2 value through cartilage endplates can be useful for the diagnosis of early intervertebral disc degeneration and the prevention of disc degeneration.

Quantitative T2 mapping of glenohumeral joint osteoarthritis: a case-control study

BackgroundT2 relaxometry is a highly sensitive technique used to assess morphological changes in the cartilage prior to anatomical changes; it provides the quantification of the disparate components of cartilage such as water, proteoglycans, and collagen. This study aims to assess T2 values of glenohumeral joint cartilage using 1.5 T magnetic resonance imaging (MRI) and comparing T2 relaxation time values between two groups—the control group and the group of patients with osteoarthritis (OA). The study was conducted among 35 OA patients (27 females and eight males; median age, 60 years; age range, 43–69 years). This group was divided into primary OA (n = 15) and secondary OA (n = 20). The control group had 30 patients (25 females and five males; median age, 46 years; age range, 30–56 years). All patients were assessed using plain radiography to determine the grade of osteoarthritis followed by a multi-echo spin pulse sequence (T2 mapping) of the coronal plane. Three areas were considered to evaluate the cartilage-humeral zone, glenoid zone, and central zones by manually drawing the region of interest (ROI). The values were compared statistically by using Mann-Whitney U tests.ResultsMedian T2 values differed significantly between the control group (43.4 ms [interquartile ranges, 41.54-45.33 ms]) and the OA patients for grades I (59.2 ms [interquartile ranges, 57.54-63.33 ms]), II (64.7 ms [interquartile ranges, 62.54-67.39 ms]), and III (61.9 ms, [interquartile ranges, 57.54-64.53 ms]). Mean T2 values were significantly higher in the different zones when comparing the OA patients whatever the cause primary or secondary (p value < 0.05) with the control group; no significant difference was noticed between the primary and secondary OA (p value > 0.05).ConclusionT2 relaxometry is a reliable, quantitative method for the assessment of the glenohumeral cartilage for significant differences in T2 values between the control group and the OA patients.

A Randomized Controlled Trial on the Effects of Low-Dose Extracorporeal Shockwave Therapy in Patients With Knee Osteoarthritis

ObjectiveTo test the efficacy of low-dose extracorporeal shockwave therapy (ESWT) on osteoarthritis knee pain, lower limb function, and cartilage alteration for patients with knee osteoarthritis. DesignRandomized controlled trial with placebo control. SettingOutpatient physical therapy clinics within a hospital network. ParticipantsEligible volunteers (N=63) with knee osteoarthritis (Kellgren-Lawrence grade II or III) were randomly assigned to 2 groups. InterventionsPatients in the experimental group received low-dose ESWT for 4 weeks while those in the placebo group got sham shockwave therapy. Both groups maintained a usual level of home exercise. Main Outcome MeasuresKnee pain and physical function were measured using a visual analog scale (VAS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Lequesne index at baseline, 5 weeks, and 12 weeks. Cartilage alteration was measured analyzing the transverse relaxation time (T2) mapping. ResultsThe VAS score, WOMAC, and Lequesne index of the ESWT group were significantly better than those of the placebo group at 5 and 12 weeks (P<.05). Both groups showed improvement in pain and disability scores over the 12-week follow-up period (P<.05). In terms of imaging results, there was no significant difference in T2 values between groups during the trial, although T2 values of the ESWT group at 12 weeks significantly increased compared to those at baseline (P=.004). The number and prevalence of adverse effects were similar between the 2 groups, and no serious side effects were found. ConclusionsA 4-week treatment of low-dose ESWT was superior to placebo for pain easement and functional improvement in patients with mild to moderate knee osteoarthritis but had some negative effects on articular cartilage.

Juvenile Osteochondritis Dissecans: Cartilage T2 Mapping of Stable Medial Femoral Condyle Lesions.

Purpose To determine whether a T2 mapping sequence could depict early changes in the composition and microstructure of cartilage overlying stable lesions of the medial femoral condyle in patients with juvenile osteochondritis dissecans (JOCD). Materials and Methods This retrospective study analyzed a sagittal T2 mapping sequence performed between September 1, 2015, and March 31, 2017, on 16 patients (10 boys and six girls; median age, 11.5 years) with 18 stable medial femoral condyle JOCD lesions and 18 age-, sex-, and skeletal maturation-matched control participants (11 boys and seven girls; median age, 11.5 years). Cartilage T2 values were quantitatively measured within regions of interest placed around the cartilage within and overlying the JOCD lesion in patients with JOCD and around the cartilage on the weight-bearing medial femoral condyle in patients with JOCD and controls. Wilcoxon signed rank and Wilcoxon rank sum tests were used to compare T2 values. Results T2 values were significantly higher (P < .001) for cartilage within the JOCD lesion than for cartilage overlying the JOCD lesion in patients with JOCD. However, there were no significant differences in T2 values between cartilage overlying the JOCD lesion and cartilage on the weight-bearing medial femoral condyle in patients with JOCD (P = .67) or in T2 values of the cartilage on the weight-bearing medial femoral condyle between patients with JOCD and controls (P = .30). Conclusion There were no significant quantifiable differences in T2 values of cartilage overlying stable JOCD lesions and normal cartilage on the medial femoral condyle, suggesting no substantial changes in cartilage composition and microstructure.

Evaluation of Water Content in Lumbar Intervertebral Discs and Facet Joints Before and After Physiological Loading Using T2 Mapping MRI.

T2 mapping was used to quantify the water content of lumbar spine intervertebral discs (IVDs) and facet joints before and after physiological loading. The aim of this study was to clarify the interaction between lumbar spine IVD and facet joints as load-bearing structures by measuring the water content of their matrix after physiological loading using T2 mapping magnetic resonance imaging (MRI). To date, few reports have functionally evaluated lumbar spine IVD and facet joints, and their interaction in vivo. T2 mapping may help detect changes in the water content of IVD and articular cartilage of facet joints before and after physiological loading, thereby enabling the evaluation of changes in interacted water retention between IVD and facet joints. Twenty asymptomatic volunteers (10 female and 10 male volunteers; mean age, 19.3 years; age range, 19-20 years) underwent MRI before and after physiological loading such as lumbar flexion, extension, and rotation. Each IVD from L1/2 to L5/S1 was sliced at center of the disc space, and the T2 value was measured at the nucleus pulposus (NP), anterior annulus fibrosus (AF), posterior AF, and bilateral facet joints. In the NP, T2 values significantly decreased after exercise at every lumbar spinal level. In the anterior AF, there were no significant differences in T2 values at any level. In the posterior AF, T2 values significantly increased only at L4/5. In the bilateral facet joints, T2 values significantly decreased after exercise at every level. There was a significant decrease in the water content of facet joints and the NP at every lumbar spinal level after dynamic loading by physical lumbar exercise. These changes appear to play an important and interactional role in the maintenance of the interstitial matrix in the IVD NP and cartilage in the facet joint. 3.

Effects of Structural Changes in Subchondral Bone on Articular Cartilage in a Beagle Dog Model

ObjectiveUsing MR T2-mapping and histopathologic score for articular cartilage to evaluate the effect of structural changes in subchondral bone on articular cartilage. MethodsTwenty-four male Beagle dogs were randomly divided into a subchondral bone defect group (n = 12) and a bone cement group (n = 12). Models of subchondral bone defectin the medial tibial plateau and subchondral bone filled with bone cement were constructed. In all dogs, the left knee joint was used as the experimental sideand the right knee as the sham side. The T2 value for articular cartilage at the medial tibial plateau was measured at postoperative weeks 4, 8, 16, and 24. The articular cartilage specimens were stained with hematoxylin and eosin, and evaluated using the Mankin score. ResultsThere was a statistically significant difference (P < 0.05) in Mankin score between the bone defect group and the cement group at postoperative weeks 16 and 24. There was a statistically significant difference in the T2 values between the bone defect group and its sham group (P < 0.05) from week 8, and between the cement group and its sham group (P < 0.05) from week 16. There was significant difference in T2 values between the two experimental groups at postoperative week 24 (P < 0.01). The T2 value for articular cartilage was positively correlated with the Mankin score (ρ = 0.758, P < 0.01). ConclusionStructural changes in subchondral bone can lead to degeneration of the adjacent articular cartilage. Defects in subchondral bone cause more severe degeneration of cartilage than subchondral bone filled with cement. The T2 value for articular cartilage increases with the extent of degeneration. MR T2-mapping images and the T2 value for articular cartilage can indicate earlycartilage degeneration.

Effects of the Inertia Barbell Training on Lumbar Muscle T2 Relaxation Time.

Sun, M-Y, Lu, J-Q, Ma, Z-C, Lü, J-J, Huang, Q, Sun, Y-N, and Liü, Y. Effects of the inertia barbell training on lumbar muscle T2 relaxation time. J Strength Cond Res 34(12): 3454-3462, 2020-The purpose of this study was to investigate variations in T2 relaxation time in normal human lumbar muscles caused by inertia barbell training. Thirty undergraduate healthy men (mean age = 19 ± 1.2 years, body mass = 72 ± 10.0 kg, and height = 1.78 ± 0.1 m) were recruited to participate in this study. Subjects were randomly assigned into 2 groups: an inertia barbell training group (IBTG) (n = 15) and a normal barbell-training group (NBTG) (n = 15). All subjects participated in lumbar flexion and extension muscle strength training for 1 hour per time, 3 times per week for a total of 8 weeks. The lumbar area of each subject was scanned before and after the experiment using a 3.0T superconductive magnetic resonance imaging system. The T2 values measured after intervention were significantly different compared with the T2 values measured before the experiment in both the IBTG and NBTG groups (p < 0.001). After intervention, there was no significant difference in T2 values between the IBTG and NBTG groups (p = 0.17). The ([INCREMENT]T2)/T2 percentage was significantly different in the IBTG group (p < 0.01). This study demonstrated that 8 weeks of strength training led to significant improvements in the values for T2 relaxation time of the lumbar muscles. Furthermore, the ([INCREMENT]T2)/T2 percentage for IBTG was higher than that for NBTG, which suggested that lumbar muscle activity increased more with inertial barbell training.

Feasibility study for evaluating early lumbar facet joint degeneration using axial T1 ρ, T2 , and T2* mapping in cartilage.

To assess the feasibility of axial T2 , T2*, and T1 ρ mapping of lumbar facet joint (LFJ) cartilage for evaluation of early degeneration. We examined a total of 176 LFJs from 21 volunteers using axial T2 , T2*, and T1 ρ mapping with a 3.0T magnetic resonance imaging (MRI) scanner. All LFJs were measured and grouped according to the presence of low back pain (LBP), the Weishaupt grading system, and the Pfirrmann grade of the adjacent intervertebral disk (IVD). T2 , T2*, and T1 ρ values were analyzed and compared among the different groups. Low interobserver agreement was found in the Weishaupt grading of LFJs (κ = 0.161). The T1 ρ values of LFJs were significantly different between adjacent two Pfirrmann grade of disks (grade I 50.15 ± 3.63 msec / grade II 53.27 ± 3.80 msec, P = 0.002; grade II 53.27 ± 3.80 msec / grade III 58.40 ± 4.17 msec, P < 0.01), and in different Weishaupt grades of LFJs (P = 0.000). T2* values were only found significantly different between Pfirrmann grade I and III of disks (P = 0.048). There was no significant difference in T2 values of LFJs whatever in Pfirrmann (P = 0.556) or Weishaupt grades (P = 0.694). No significant difference was found in T2 , T2*, and T1 ρ values between volunteers with LBP and without LBP (PT2 = 0.783, PT2*=0.311, PT1 ρ = 0.259). Axial T1 ρ could be an effective and sensitive method to assess for early degenerative changes in LFJ cartilage. 1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:468-475.

A preliminary study of the T1rho values of normal knee cartilage using 3 T-MRI

To investigate the degree of the effect of aging and weight-bearing on T1rho values in normal cartilage. Thirty-two asymptomatic patients were examined using 3.0-T magnetic resonance imaging (MRI) to determine knee cartilage T1rho values and T2 values. The femoral and tibial cartilage was divided into weight-bearing (WB-Rs) and less-weight-bearing (LWB-Rs) regions. Single regression analysis was used to assess the relationship between cartilage T1rho values and age and between T2 values and age. Analysis of variance and post hoc-testing were used to evaluate differences in WB-Rs and LWB-Rs cartilage T1rho values and T2 values. Multiple linear regression modeling was performed to predict cartilage T1rho values. Cartilage T1rho values correlated positively with age for all cartilage regions tested (p<0.001). There were no significant correlations between cartilage T2 values and age. In both the medial femoral and tibial cartilage, T1rho values were significantly higher in WB-Rs than in LWB-Rs (p<0.05). There were no significant differences in T2 values between WB-Rs and LWB-Rs. Multiple linear regression analysis showed that both age and weight-bearing were significant predictors of increased medial knee cartilage T1rho values (p<0.001). Aging and the degree of weight-bearing correlate with the change in cartilage T1rho values. Based on multiple regression modeling, aging may be a more important factor than weight-bearing for cartilage T1rho values.

Analysis of Degenerative Discs in Lumbar Spondylolisthesis Using MRI T2 Mapping

Background: Spinal instability, including lumbar degenerative spondylolisthesis (DS), mainly results from degeneration of intervertebral discs (IVD) and the facet joints (FJ). Characterization of the relationship between IVD degeneration in cases of lumbar degenerative spondylolisthesis (DS), and T2 values may be useful for accurate noninvasive evaluation and subsequent treatment. Thus, the goal of this study was to measure T2 values of IVDs in cases with (DS) and without (NS) spondylolisthesis, and to characterize changes of IVDs in DS. Methods: A total of 40 subjects who presented with L4 spondylolisthesis comprised the DS group. Another 40 subjects who did not have lumbar spondylolisthesis, constituted the NS group. T2 values of IVDs were measured and compared in these groups. Results: T2 values for IVDs tended to be lower in the DS group than in the NS group, and these values were significantly different (p < 0.01) within the anterior annulus fibrosus (AF). No significant differences in T2 values between Meyerding grades I and II were observed in any areas of IVDs. Conclusions: It is speculated that in the early stages, the degeneration of the anterior AF develops and is related to the onset of lumbar spondylolisthesis, while in later stages, degeneration of facet joints influences the progression of spondylolisthesis.

Physical activity is associated with magnetic resonance imaging–based knee cartilage T2 measurements in asymptomatic subjects with and those without osteoarthritis risk factors

To evaluate the association of exercise and knee-bending activities with magnetic resonance imaging (MRI)-based knee cartilage T2 relaxation times and morphologic abnormalities in asymptomatic subjects from the Osteoarthritis Initiative, with or without osteoarthritis (OA) risk factors. We studied 128 subjects with knee OA risk factors and 33 normal control subjects ages 45-55 years, with a body mass index of 18-27 kg/m(2) and no knee pain. Subjects were categorized according to exercise level, using the leisure activity component of the Physical Activity Scale for the Elderly, and by self-reported frequent knee-bending activities. Two radiologists graded the cartilage of the right knee on MR images, using the Whole-Organ MRI Score (WORMS). Cartilage was segmented, and compartment-specific T2 values were calculated. Differences between the exercise groups and knee-bending groups were determined using multiple linear and logistic regression models. Among subjects with risk factors for knee OA, light exercisers had lower T2 values compared with sedentary and moderate/strenuous exercisers. When the sexes were analyzed separately, female moderate/strenuous exercisers had higher T2 values compared with sedentary individuals and light exercisers. Subjects without risk factors displayed no significant differences in T2 values according to exercise level. However, frequent knee-bending activities were associated with higher T2 values in both subjects with OA risk factors and those without OA risk factors and with more severe cartilage lesions in the group with risk factors. In subjects at risk of knee OA, light exercise was associated with low T2 values, whereas moderate/strenuous exercise in women was associated with high T2 values. Higher T2 values and WORMS grades were also observed in frequent knee-benders, suggesting greater cartilage degeneration in these individuals.

Correlation between T2 relaxation time and intervertebral disk degeneration

Magnetic resonance T2 mapping allows for the quantification of water and proteoglycan content within tissues and can be used to detect early cartilage abnormalities as well as to track the response to therapy. The goal of the present study was to use T2 mapping to quantify intervertebral disk water content according to the Pfirrmann classification. This study involved 60 subjects who underwent lumbar magnetic resonance imaging (a total of 300 lumbar disks). The degree of disk degeneration was assessed in the midsagittal section on T2-weighted images according to the Pfirrmann classification (grades I to V). Receiver operating characteristic (ROC) analysis was performed among grades to determine the cut-off values. In the nucleus pulposus, T2 values tended to decrease with increasing grade, and there was a significant difference in T2 values between each grade from grades I to IV. However, there was no significant difference in T2 values in the anterior or posterior annulus fibrosus. T2 values according to disk degeneration level classification were as follows: grade I (>116.8ms), grade II (92.7-116.7ms), grade III (72.1-92.6ms), grade IV (<72.0ms). T2 values decreased with increasing Pfirrmann classification grade in the nucleus pulposus, likely reflecting a decrease in proteoglycan and water content. Thus, T2 value-based measurements of intervertebral disk water content may be useful for future clinical research on degenerative disk diseases.

Cartilage in Anterior Cruciate Ligament–Reconstructed Knees: MR Imaging T1ρand T2—Initial Experience with 1-year Follow-up

To longitudinally evaluate cartilage matrix changes by using magnetic resonance (MR) imaging T1(ρ) (T1 relaxation time in rotating frame) and T2 quantification and to study the relationship between meniscal damage and cartilage degeneration in anterior cruciate ligament (ACL)-reconstructed knees. This was an institutional review board-approved, HIPAA-compliant study. Informed consent was obtained. Twelve patients with acute ACL injuries were imaged with 3.0-T MR imaging at baseline (after injury and prior to ACL reconstruction) and 1 year after ACL reconstruction. Ten age-matched healthy subjects were studied as controls. Cartilage T1(ρ) and T2 were quantified in full thickness, superficial, and deep layers of defined subcompartments at baseline and follow-up in ACL-injured knees and were compared with measures acquired in matched regions of control knees. Meniscal lesions were graded by using modified subscores of the Whole-Organ Magnetic Resonance Imaging Score system. T1(ρ) values of the posterolateral tibial cartilage in ACL-injured knees were significantly elevated at baseline compared with T1(ρ)values of control knees and were not fully recovered at 1-year follow-up. T1(ρ) values of weight-bearing medial femorotibial cartilage in ACL-injured knees were significantly elevated at 1-year follow-up compared with those of control knees. No significant differences in T2 values between ACL-injured and control knees were found. Patients with lesions in the posterior horn of the medial meniscus showed a greater increase of T1(ρ) and T2 from baseline to follow-up in adjacent cartilage than patients without lesions in the medial meniscus. Quantitative MR imaging T1(ρ) and T2 enable detection of changes in the cartilage matrix of ACL-reconstructed knees as early as 1 year after ACL reconstruction.