T2 Mapping Of Cartilage Research Articles

Proton Density Fat-Fraction of Rotator Cuff Muscles Is Associated With Isometric Strength 10 Years After Rotator Cuff Repair: A Quantitative Magnetic Resonance Imaging Study of the Shoulder

Background: Quantitative muscle fat-fraction magnetic resonance (MR) imaging techniques correlate with semiquantitative Goutallier scores with failure after rotator cuff (RC) repair. Purpose: To investigate the relationship of proton density fat fraction (PDFF) of the RC muscles with semiquantitative MR scores, cartilage T2 relaxation times, and clinical isometric strength measurements in patients 10 years after unilateral RC repair. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Bilateral shoulder MR imaging was performed in 13 patients (11 male, 2 female; age, 72 ± 8 years) 10.9 ± 0.4 years after unilateral autologous periosteal flap augmented RC repair (total shoulders assessed, N = 26). Goutallier classification, muscle atrophy, RC tendon integrity, and cartilage defects were determined based on morphological MR sequences. A paracoronal 2D multi-slice multi-echo sequence was used for quantitative cartilage T2 mapping. A chemical shift-encoding-based water-fat separation technique (based on a 6-echo 3D spoiled gradient echo sequence) was used for quantification of the PDFF of RC muscles. Isometric shoulder abduction strength was measured clinically. Mean and SD, Pearson correlation, and partial Spearman correlation were calculated. Results: There were 6 RC full-thickness retears in ipsilateral shoulders and 6 RC full-thickness tears in contralateral shoulders. Isometric shoulder abduction strength was not significantly different between ipsilateral and contralateral shoulders (50 ± 24 N vs 54 ± 24 N; P = .159). The mean PDFF of RC muscles was 11.7% ± 10.4% (ipsilateral, 14.2% ± 8.5%; contralateral, 9.2% ± 7.8%; P = .002). High supraspinatus PDFF correlated significantly with higher Goutallier scores (R = 0.75, P < .001) and with lower isometric muscle strength (R = −0.49, P = .011). This correlation remained significant after adjustment for muscle area measurements and tendon rupture (R = −0.41, P = .048). More severe cartilage defects at the humerus were significantly associated with higher supraspinatus PDFF (R = 0.44; P = .023). Cartilage T2 values did not correlate with muscle PDFF (P > .05). Conclusion: MR imaging–derived RC muscle PDFF is associated with isometric strength independent of muscle atrophy and tendon rupture in shoulders with early and advanced degenerative changes. It therefore provides complementary, clinically relevant information in tracking RC muscle composition on a quantitative level.

Comparison of t2 and t1ρ Mapping of Ankle Cartilage between Young Healthy Females and Dancers

Comparison of t2 and t1ρ Mapping of Ankle Cartilage between Young Healthy Females and Dancers

A descriptive study of potential effect of anterior tibial translation, femoral tunnel and anterior cruciate ligament graft inclination on clinical outcome and degenerative changes

IntroductionThere is no evidence that anatomically correct anterior cruciate ligament reconstruction (ACLR) offers lower rate of degenerative changes development or that it would lead to a better outcome. The significance and understanding of the abnormal anterior tibial translation (ATT) in ACLR patients is yet to be established.MethodsSixty subjects (40 patients at 5.9 years after ACLR, 20 healthy controls) underwent 3 T MRI. Quantitative cartilage T2 mapping and morphological whole organ magnetic resonance imaging score (WORMS) evaluation was performed. Self-reported questionnaires were used for subjective clinical evaluation. Correlations were calculated with the following MRI measurements; femoral tunnel inclination, ACL graft inclination, lateral and medial compartment ATT.ResultsIn the ACLR group positive correlation was found between the patellar cartilage T2 values and sagittal ACL graft inclination. In the ACLR group lateral compartment ATT showed negative correlation with ACL graft inclination and subjective clinical evaluation, and positive correlation with morphological degenerative changes. Femoral tunnel showed positive correlation with ACL graft inclination in the same plane.ConclusionsIncreased ATT offers worse clinical outcome and increased rate of degenerative changes. Furthermore, ATT is affected by the ACL inclination. Inclination of the drilling tunnel affects ACL graft inclination; thereby independent drilling techniques provide superior results of anatomical ACL graft positioning.

Retrospective quantitative cartilage and semi-quantitative morphological evaluation at 6years after ACL reconstruction.

Purpose We analyzed anterior cruciate ligament reconstruction (ACLR) patients in order to evaluate degenerative changes and the effect of meniscal insufficiency at mid-term follow-up. Sixty subjects (40 patients at 5.9years after ACLR, 20 healthy controls) underwent 3T MRI. Quantitative cartilage T2 mapping and morphological Whole Organ Magnetic Resonance Imaging Score (WORMS) evaluation were performed. Self-reported questionnaires were used for subjective clinical evaluation. Based on the meniscal status at ACLR, further subdivision within each compartment (lateral and medial) was made: menisci intact and menisci insufficient. The ACLR subjects showed significantly elevated T2 values and higher WORMS scores compared to the control group. T2 values of the anterior lateral femoral subcompartment were significantly higher in menisci insufficient group compared to the control group. In both compartments significantly higher WORMS scores were observed in the menisci insufficient group compared to the menisci intact group. ACLR knees exhibit cartilage matrix and morphological degeneration at mid-term follow-up. Lateral meniscal insufficiency noted at ACLR presents a higher risk of developing degenerative changes than does the medial meniscus insufficiency; however, this difference may not be detected clinically.

T2 mapping of articular cartilage of the glenohumeral joint at 3.0T in healthy volunteers: a feasibility study.

The purpose of this study was to assess the T2 values of the glenohumeral joint cartilage in healthy asymptomatic individuals at 3.0T and to analyze the T2 profile of the humeral cartilage. This prospective study was approved by our institutional review board and written informed consent was obtained. Thirteen subjects (mean age, 28.6years; age range, 24-33 years) were included and underwent multiecho spin-echo T2-weighted MR imaging and T2 mapping was acquired. Regions of interest were placed on the humeral cartilage and glenoid cartilage on oblique coronal images. T2 profiles of humeral cartilage were measured from the bone-cartilage interface to the articular surface. Intra-observer agreement was analyzed using intraclass correlation coefficient (ICC). All 13 joints showed normal appearance on conventional T2-weighted images. The mean T2 values of humeral and glenoid cartilage were 50.5 ± 12.1 and 49.0 ± 9.9ms, respectively. Intra-observer agreement was good, as determined by ICC (0.736). Longer T2 values were observed at the articular surface with a tendency to decrease toward the bone-cartilage interface. The mean cartilage T2 value was 69.03 ± 21.2ms at the articular surface and 46.99 ± 19.6ms at the bone-cartilage interface. T2 values of the glenohumeral joint cartilage were similar to reported values of cartilage in the knee. The T2 profile of normal humeral cartilage showed a spatial variation with an increase in T2 values from the subchondral bone to the articular surface.

Change of cartilage T2 in contralateral hip joint after total hip arthroplasty

Purpose: Disruption or alteration of the cartilage matrix such as a decrease in the concentration of proteoglycan and an increase in water content is found histologically in early changes of osteoarthritis mapping of the articular cartilage T2 is one technique in joint magnetic resonance imaging (MRI) that elucidates degenerative changes associated with changes in water contents and damage to the collagen network. It is unknown how total hip arthroplasty of one side of hip joints could reduce load applied on that cartilage of the other side of them. The purpose of this study was to evaluate those changes in cartilage T2 values of contralateral hip joint after total hip arthroplasty. Methods: 10 consecutive patients (10 hips), who had previously been diagnosed osteoarthritis in one side of their hip joints, were included in this study. There were all female patients (mean age, 58 years; range 48–72 years). All patients were followed up longitudinally, and MRI of both hip joints were performed before total hip arthroplasty and three months after the surgery. Each subjects’ hip was imaged using an multi-slice multi-echo (MSME) T2 mapping technique on a 1.5T MR imaging system (Siemens Healthcare, Erlangen, Germany) in the sagittal plane with the subject lying supine. ROIs were drawn manually by an experienced orthopaedic surgeon in the weight-bearing area on the acetabular and femoral cartilage. Central medial, as well as central lateral slices, were evaluated in each subject. Mean, standard deviation, and pixel count were recorded and statistically analyzed by t-test. Results: T2 values in contralateral hip cartilage exhibited a significant increase in the lateral ROI of the acetabular cartilage (54.8ms±7.5 → 59.6ms±6.2, p< 0.05), and a significant increase in the lateral ROI of the femoral cartilage (51.6ms±7.4 → 56.4.5ms±7.5, p< 0.05). On the other hand, T2 values in contralateral hip cartilage didn’t exhibit a significant increase in the medial ROI of the acetabular and femoral cartilage. Conclusions: While performing daily activities such as standing or walking, the articular cartilage in the hip joint is subjected to substantial external loading, which leads to cartilage deformation along with alteration in the collagen architecture or water distribution within the cartilage. Among all MRI parameters, cartilage T2 mapping of cartilage is influenced by water content and collagen fiber orientation of cartilage and is indicated as a potent quantitative index for the load response of the articular cartilage. Our results indicated that total hip arthroplasty in one side of the hip joint reduced static loading on the cartilage in the other side of hip joint by the assessment of cartilage T2 mapping in the lateral ROI on both acetabular and femoral cartilage. It may provide more sensitive and detailed assessment of degenerative pathological changes and load-bearing function of the cartilage.

Isotropic three-dimensional T2 mapping of knee cartilage with T2-prepared segmented gradient ECHO at 3T

Isotropic three-dimensional T2 mapping of knee cartilage with T2-prepared segmented gradient ECHO at 3T

No Difference on Quantitative Magnetic Resonance Imaging in Patellofemoral Cartilage Composition Between Patients With Patellofemoral Pain and Healthy Controls

Background: Retropatellar cartilage damage has been suggested as an etiological factor for patellofemoral pain (PFP), a common knee condition among young and physically active individuals. To date, there is no conclusive evidence for an association between cartilage defects and PFP. Nowadays, advanced quantitative magnetic resonance imaging (MRI) techniques enable estimation of cartilage composition. Purpose: To investigate differences in patellofemoral cartilage composition between patients with PFP and healthy control subjects using quantitative MRI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients with PFP and healthy control subjects underwent 3.0-T MRI including delayed gadolinium-enhanced MRI of cartilage and T1ρ and T2 mapping. Differences in relaxation times of patellofemoral cartilage were compared between groups by linear regression analyses, adjusted for age, body mass index, sex, sports participation, and time of image acquisition. Results: This case-control study included 64 patients and 70 controls. The mean (±SD) age was 23.2 ± 6.4 years and the mean body mass index was 22.9 ± 3.4 kg/m2; 56.7% were female. For delayed gadolinium-enhanced MRI of cartilage, the mean T1GD relaxation times of patellar (657.8 vs 669.4 ms) and femoral cartilage (661.6 vs 659.8 ms) did not significantly differ between patients and controls. In addition, no significant difference was found in mean T1ρ relaxation times of patellar (46.9 vs 46.0 ms) and femoral cartilage (50.8 vs 50.2 ms) and mean T2 relaxation times of patellar (33.2 vs 32.9 ms) and femoral cartilage (36.7 vs 36.6 ms) between patients and controls. Analysis of prespecified medial and lateral subregions within the patellofemoral cartilage also revealed no significant differences. Conclusion: There was no difference in composition of the patellofemoral cartilage, estimated with multiple quantitative MRI techniques, between patients with PFP and healthy control subjects. However, clinically relevant differences could not be ruled out for T1ρ in the adolescent population. Retropatellar cartilage damage has long been hypothesized as an important factor in the pathogenesis of PFP, but study findings suggest that diminished patellofemoral cartilage composition is not associated with PFP.

Progression of cartilage degeneration and clinical symptoms in obese and overweight individuals is dependent on the amount of weight loss: 48-month data from the Osteoarthritis Initiative

To investigate compositional cartilage changes measured with 3T MRI-based T2 values over 48 months in overweight and obese individuals with different degrees of weight loss (WL) and to study whether WL slows knee cartilage degeneration and symptom worsening. We studied participants from the Osteoarthritis Initiative with risk factors or radiographic evidence of mild to moderate knee osteoarthritis with a baseline BMI ≥25kg/m(2). We selected subjects who over 48 months lost a, moderate (BMI change, 5-10%WL, n=180) or large amount of weight (≥10%WL, n=78) and frequency-matched these to individuals with stable weight (<3%, n=258). Right knee cartilage T2 maps of all compartments and grey-level co-occurrence matrix (GLCM) texture analyses were evaluated and associations with WL and clinical symptoms (WOMAC subscales for pain, stiffness and disability) were assessed using multivariable regression models. The amount of weight change was significantly associated with change in cartilage T2 of the medial tibia (β 0.9ms, 95% CI 0.4 to 1.1, P=0.001). Increase of T2 in the medial tibia was significantly associated with increase in WOMAC pain (β 0.5ms, 95% CI 0.2 to 0.6, P=0.02) and disability (β 0.03ms, 95% CI 0.003 to 0.05, P=0.03). GLCM contrast and variance over all compartments showed significantly less progression in the >10%WL group compared to the stable weight group (both comparisons, P=0.04). WL over 48 months is associated with slowed knee cartilage degeneration and improved knee symptoms.

Clinical outcome and T2 assessment following autologous matrix-induced chondrogenesis in osteochondral lesions of the talus

Scientific evidence for the treatment of osteochondral lesions (OCLs) of the talus is limited. The aim of this study was an evaluation of the clinical outcome after a one-step autologous subchondral cancellous bone graft and autologous matrix-induced chondrogenesis (AMIC) in medial OCLs of the talus and the assessment of the repair tissue (RT). Seventeen patients (eight women, nine men; mean age, 38.8 ± 15.7 years) with an OCL of the medial talus underwent surgery. Clinical and radiological assessment was performed after a mean follow-up of 39.5 ± 18.4 months, including established scoring systems (American Orthopaedic Foot and Ankle Society [AOFAS] Score, Foot Function Index [FFI], visual analogue scale [VAS]), evaluation of Magnetic Resonance Observation of Cartilage Repair Tissue scoring system (MOCART Score) and T2 mapping. Preoperative pain (7.8 ± 2.1) significantly improved to an average of 3.2 ± 2.4 postoperatively. AOFAS Score averaged 82.6 ± 13.4, MOCART Score 52.7 ± 15.9. Mean T2 relaxation time of the RT was 41.6 ± 6.3 ms and showed no significant differences to the surrounding cartilage (mean, 38.8 ± 8.5; p = 0.58). MOCART Score significantly correlated with the AOFAS Score (rho = 0.574, p = 0.040). T2 relaxation time of the RT significantly correlated with the MOCART Score (rho = 0.593, p = 0.033). The one-step autologous subchondral cancellous bone grafting and AMIC leads to a significant reduction in postoperative pain and satisfying postoperative functional outcome in mid-term follow-up. Magnetic resonance imaging (MRI) assessment demonstrated a good quality of regenerative tissue similar to the MRI ultrastructure of the surrounding cartilage.

7 Tesla quantitative hip MRI: T1, T2 and T2* mapping of hip cartilage in healthy volunteers.

To evaluate the technical feasibility and applicability of quantitative MR techniques (delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T2 mapping, T2* mapping) at 7T MRI for assessing hip cartilage. Hips of 11 healthy volunteers were examined at 7T MRI with an 8-channel radiofrequency transmit/receive body coil using multi-echo sequences for T2 and T2* mapping and a dual flip angle gradient-echo sequence before (T10) and after intravenous contrast agent administration (T1Gd; 0.2mmol/kg Gd-DTPA(2-) followed by 0.5h of walking and 0.5h of rest) for dGEMRIC. Relaxation times of cartilage were measured manually in 10 regions of interest. Pearson's correlations between R1delta = 1/T1Gd - 1/T10 and T1Gd and between T2 and T2* were calculated. Image quality and the delineation of acetabular and femoral cartilage in the relaxation time maps were evaluated using discrete rating scales. High correlations were found between R1delta and T1Gd and between T2 and T2* relaxation times (all p < 0.01). All techniques delivered diagnostic image quality, with best delineation of femoral and acetabular cartilage in the T2* maps (mean 3.2 out of a maximum of 4 points). T1, T2 and T2* mapping of hip cartilage with diagnostic image quality is feasible at 7T. To perform dGEMRIC at 7T, pre-contrast T1 mapping can be omitted. • dGEMRIC of hip cartilage with diagnostic image quality is feasible at 7 T. • To perform dGEMRIC at 7 T, pre-contrast T1 mapping can be omitted. • T2(*) mapping of hip cartilage with diagnostic image quality is feasible at 7 T. • T2 and T2* relaxation times of cartilage were highly correlated at 7 T. • Best delineation of femoral and acetabular cartilage was found in T2* maps.

Bilateral cartilage T2 mapping 9 years after Mega-OATS implantation at the knee: a quantitative 3T MRI study

To evaluate morphological and quantitative MR findings 9 years after autograft transfer of the posterior femoral condyle (Mega-OATS) and to correlate these findings with clinical outcomes. Quantitative MR measurements were also obtained of the contralateral knee and the utility as reference standard was investigated. Both knees of 20 patients with Mega-OATS osteochondral repair at the medial femoral condyle (MFC) were studied using 3T MRI 9 years after the procedure. MR-sequences included morphological sequences and a 2D multislice multiecho (MSME) spin echo (SE) sequence for quantitative cartilage T2 mapping. Cartilage segmentation was performed at the cartilage repair site and six additional knee compartments. Semi-quantitative MR observation of cartilage repair tissue (MOCART) scores and clinical Lysholm scores were obtained. Paired t-tests and Spearman correlations were used for statistical analysis. Global T2-values were significantly higher at ipsilateral knees compared to contralateral knees (42.1±3.0ms vs 40.4±2.6ms, P=0.018). T2-values of the Mega-OATS site correlated significantly with MOCART scores (R=-0.64, P=0.006). The correlations between MOCART and Lysholm scores and between absolute T2-values and Lysholm scores were not significant (P>0.05). However, higher T2 side-to-side differences at the femoral condyles correlated significantly with more severe clinical symptoms (medial, R=-0.53, P=0.030; lateral, R=-0.51, P=0.038). Despite long-term survival, 9 years after Mega-OATS procedures, T2-values of the grafts were increased compared to contralateral knees. Clinical scores correlated best with T2 side-to-side differences of the femoral condyles, indicating that intraindividual adjustment may be beneficial for outcome evaluation.

Comparison of T2 Values in the Lateral and Medial Portions of the Weight-Bearing Cartilage of the Hip for Patients With Symptomatic Femoroacetabular Impingement and Asymptomatic Volunteers

To develop a simplified method to define a clinically relevant subregion in the course of arthroscopic treatment of femoroacetabular impingement (FAI) using T2 mapping in patients and asymptomatic volunteers. Additionally, we sought to compare the lateral and medial subregion values in asymptomatic volunteers and in patients presenting with FAI. Finally, we wanted to investigate possible associations between patients' T2 mapping values and demographic variables-i.e., alpha angle, age, sex, and body mass index (BMI). Twenty-five asymptomatic volunteers and 23 consecutive symptomatic patients with FAI (cam or mixed type) were prospectively enrolled and evaluated with a sagittal T2 mapping sequence. The weight-bearing region of the acetabular and femoral cartilage was manually segmented and divided into medial and lateral subregions. Median T2 values were determined, and patient characteristics were assessed as potential predictors of T2 values. T2 values in the lateral portion of the acetabulum were lower than in the medial portion for both asymptomatic volunteers (43 v 53 ms; P < .001) and patients with FAI (42 v 49 ms; P=.016). The medial acetabulum (MA) of asymptomatic volunteers had higher T2 values than those of the FAI group (53 v 49 ms; P= .040). The lateral-minus-medial difference was significantly larger among asymptomatic volunteers than in patients with FAI (P= .047). Patients with FAI had higher alpha angles than those of the asymptomatic volunteers, but no other associations with patient characteristics were observed. This study's findings suggest that there are differences in cartilage T2 mapping values between medial and lateral weight-bearing aspects of the hip and may expand the application and usefulness of biochemical magnetic resonance imaging (MRI) techniques, specifically T2 mapping, in the diagnosis of hip cartilage damage with the evaluation of clinically relevant subregions. When comparing asymptomatic volunteers and patients with FAI presenting with cam or mixed type deformity, we observed a significant contrast between the T2 mapping values of the lateral and medial portions of the weight-bearing zone of the acetabular cartilage, whereas such contrast was not observed when zone 3 was analyzed as a whole. Level III, development of diagnostic criteria on the basis of consecutive patients with a universally applied reference gold standard.

Characterization of tibiofemoral cartilage T2 mapping in the contact and non-contact regions during walking using dual fluoroscopy and magnetic resonance imaging

Characterization of tibiofemoral cartilage T2 mapping in the contact and non-contact regions during walking using dual fluoroscopy and magnetic resonance imaging

Cartilage T2 Mapping in Anatomically Reconstructed ACL Knees Compared to the Uninjured Contralaterals

Cartilage T2 Mapping in Anatomically Reconstructed ACL Knees Compared to the Uninjured Contralaterals

A Comparison of Knee Joint Biomechanics during Gait and Cartilage T2 Mapping Values in Asymptomatic Women in their Twenties and Forties

Objective: To investigate the difference in knee joint kinematics and kinetics during gait and T2 mapping values in a healthy female population in their twenties and forties in order to determine the knee motion changes related to early knee OA change. Methods: Thirty healthy women, 15 in their 20s and 15 in their 40s, participated (average ages 22.1 ± 2.4 and 45.7 ± 2.5 years old, respectively). Knee joint kinematic and kinetic data during gait and T2 measurements of the medial femorotibial joint cartilage using a 3T MR system were assessed. Results: The first peaks of knee adduction moment (KAM) in women in their 20s and 40s were not significantly different, although the first peaks of knee flexion moment in their 40s (5.7×10-2 ± 1.7×10-2) were significantly greater than the values in their 20s (3.2×10-2 ± 2.6×10-2, P<0.05). T2 values of the femoral superficial cartilage in the 40s (34.0 ± 1.8 msec) were significantly longer than the values in the 20s (32.2 ± 1.4 msec) (P<0.01). The first peak of the knee flexion moment and the T2 values in the 40s were not significantly correlated (r =-0.21). Conclusion: Although T2 values at the medial superficial femoral cartilage in the 40s were longer than in the 20s, the knee flexion moment was not related to T2 values of knee joint cartilage in the 40s.

USPIO-related T1 and T2 mapping MRI of cartilage in a rabbit model of blood-induced arthritis: a pilot study.

Ultrasmall paramagnetic iron oxide (USPIO)-enhanced MRI is promising for evaluating inflammation. The aims of this study were to investigate the effect of USPIO on cartilage T1 and T2 mapping, and to evaluate a proposed rapid vs. conventional T2 map method for imaging cartilage in a blood-induced arthritis model. Knees of nine arthritic (induction by intra-articular autologous blood injection) and six control rabbits were imaged over time (baseline, weeks 1, 5, 10) by 1.5 T MRI. All rabbits had USPIO (35-75 μmol Fe/kg)-enhanced MRI at each time point. T1 and T2 (conventional and rapid) maps and signal-to-noise ratios (SNR) were obtained pre- and post-USPIO administration. Cartilage biochemistry and histology were compared with MRI. Excellent correlations were noted between T1 map values and histologic scores at week 10 pre-USPIO (medial, r = 0.93, P = 0.0007; lateral, r = 0.87, P = 0.005) in the arthritic group, but not between T2 map and histology. Marginally and significant differences were observed between pre- and post-USPIO T2 values at weeks 5 (P = 0.06) and 10 (P = 0.02), but only with the administration of high USPIO doses in the arthritic group using the conventional method. No significant differences were noted between pre- and post-USPIO T1 values at any imaging time points. Cartilage T2 maps with short-TR and conventional protocols provided similar T2 values [(decreased trend)] (P > 0.05). Concomitant use of USPIO to T1 and T2 mapping of cartilage would not impair the identification of interval changes of T1 and T2 maps. Rapid T2 map provides similar results compared to conventional method, but its validation warrants further investigation.

Pre- and postcontrast T1 and T2 mapping of patellar cartilage in young adults with recurrent patellar dislocation.

To examine the cartilage quality in young adults with recurrent patellar dislocation in childhood using different magnetic resonance imaging parameters. Sixteen young adults with unilateral recurrent patellar dislocation were investigated ≥5 y (mean, 8.5 y) after the first dislocation. Pre- and postcontrast T1 and precontrast T2 relaxation times were analyzed in four superficial and four deep patellar cartilage regions of both knees. Two hours after intravenous injection of 0.2 mM/kg Gd-DTPA(2-), postcontrast T1 [T1(Gd)] and ΔR1 [1/T1 (precontrast) - 1/T1 (postcontrast)] were analyzed in the regions. Muscle performance and patient-reported outcome were evaluated. When comparing the injured side with the noninjured side, differences were seen in the superficial half but not the deep half of the cartilage. T1(Gd) was shorter in the central part, whereas T2 was shorter in the periphery of the patellar cartilage (P < 0.05). ΔR1 demonstrated similar differences between healthy and diseased cartilage as T1(Gd) alone. The knee function was not correlated to the degenerative changes. The short T1(Gd) centrally indicates degenerative cartilage changes consistent with loss of glycosaminoglycans. Precontrast and ΔR1 calculations may be excluded in clinical dGEMRIC, which simplifies the procedure. A decrease in T2 may be a very early sign of joint pathology but warrants further investigation.

DIagnosis of morphological internal knee derangements associated with osteoarthritis on magnetic resonance imaging sequences for quantitative T2 and T1rho mapping of articular cartilage composition.

Purpose: Novel quantitative magnetic resonance imaging (MRI) techniques for articular cartilage composition show promise for early detection of osteoarthritis (OA). However, large-scale application of quantitative MRI techniques in clinical OA research studies or in routine clinical patient care is hampered by long scan times. Implementation of quantitative MRI techniques may become more widespread if they can be applied as a replacement of routine morphological knee MRI pulse sequences rather than an extension of the MRI protocol. This study aimed to assess the diagnostic performance of a novel 3D fast spin-echo (FSE) T2 and T1rho sequence for quantitative mapping of articular cartilage composition for the detection of internal knee derangements. We focused on cruciate ligament and meniscal tears, which are among the most common internal knee derangements on MRI and are associated with (early) OA. We also determined the performance for diagnosis of bone marrow lesions and cartilage defects, which are morphological features of established OA. Methods: 39 patients underwent routine clinical MRI of the knee on a 3T MRI scanner (Discovery MR750, GE Healthcare, Waukesha, WI) using a 16-channel flexible wrap-around coil (GEM Flex Coil, NeoCoil, Pewaukee, WI). The MRI protocol consisted of 5 routine 2D FSE clinical knee MRI pulse sequences in three orthogonal planes, and was extended with novel 3D pseudo-steady-state FSE sequences for the purpose of quantitative T2 and T1rho mapping of articular cartilage (sagittal plane, slice thickness 3mm, matrix 384x256, number of excitations 0.5, field of view 15 cm, scan time 6:49 minutes for T2 and 6:37 minutes for T1rho). Three separate de-identified MRI datasets with randomized patient order were created consisting of morphological, quantitative T2, and T1rho images. An experienced musculoskeletal radiologist evaluated all MRIs for anterior and posterior cruciate ligament (ACL and PCL) complete tears, andmedial and lateral meniscal tears. Bone marrow lesions (BMLs) and cartilage defects were also assessed according to the semi-quantitative MRI Osteoarthritis Knee Score (MOAKS). In patients who subsequently underwent knee arthroscopy, the orthopaedic surgeon systematically assessed intra-articular pathology using the International Cartilage Repair Society (ICRS) scoring system. Diagnostic performance statistics were calculated for aforementioned morphological abnormalities on the T2 mapping and T1rho mapping sequence separately, only including lesions with a frequency of 5 more in our study population. Arthroscopic findings were used as reference standard for 23 patients that underwent arthroscopy, whereas for the other 16 patients we used routine morphological MRI as the reference. Results: Only four lateral meniscal tears and no PCL tears were diagnosed. The 3D FSE T1rho sequence demonstrated good sensitivity and excellent specificity for the diagnosis for ACL tears and medial meniscal tears, and generally showed better diagnostic performance than the T2 mapping 3D FSE sequence (Table 1). For both sequences, sensitivity was poor for the detection of cartilage lesions, BMLs, and lateral meniscal tears. Illustrative examples of normal and abnormal internal knee structures are shown in Figure 1. Conclusions: A 3D FSE T1rho sequence for quantitative mapping of articular cartilage composition shows good diagnostic performance for the anatomic diagnosis of ACL tears and medial meniscal tears. In MRI studies focused on these OA associated internal knee derangements, this sequence may replace routine clinical pulse sequences, enhancing scan time efficiency and potentially accelerating largescale application in clinical OA research and routine clinical patient care. The poor diagnostic performance for BMLs and cartilage lesions may be less relevant with the availability of more sensitive indicators of OA status provided by these sequences, i.e. quantitative information on cartilage composition and quality. Examining quantitative T2 or T1rho information from these sequences along with the underlying morphologic images could enhance detection of cartilage and bone marrow lesions. We also expect that diagnostic performance would benefit from isotropic acquisition methods that enable multi-planar reconstructions.

A comparison of knee joint biomechanics during free gait and cartilage T2 mapping values in healthy individuals in their twenties and forties

A comparison of knee joint biomechanics during free gait and cartilage T2 mapping values in healthy individuals in their twenties and forties