Dear Editor, I read the article by Gübitz et al. [1] with great interest. The data provided by the authors are highly valuable, since even though numerous publications on T2 / T2*/T1rho relaxometry of lumbar intervertebral discs have been published, most of those studies were based on a small sample of selected volunteers or on patients with non-specific low back pain (LBP) who may or may not have disc pathologies associated with LBP. T2 / T2*/T1rho relaxometry data sampled from a general population remain scare [2]. T1rho demonstrates a number of advantages over conventional T2 for disc degeneration evaluation [3, 4], particularly for annulus fibrosis. Knowledge of the normal range of T1rho values in the healthy spine is important for further investigation of disc degeneration and other pathologies [5]. Disc T1rho may be region-specific, agespecific, as well as gender-specific. The fact that disc T1rho is region-specific has been reported and also demonstrated in the study by Gübitz et al. [1]. Disc T1rho is age-specific due to the physiological aging process even in the absence of pathological disc degeneration [6]. It is noteworthy that the study by Gübitz et al. demonstrated that body mass index (BMI) shows a negative correlation with T1rho of the lumbar disc [1]. This may additionally suggest the sensitivity of the T1rho technique for disc pathologies. The study by Gübitz et al. also examined whether disc T1rho might be gender-specific. Gender specificity was not observed. For a population under the age of fifty, previous studies showed that lumbar disc injury and disc degeneration are more common in men than in women [7, 8]. However, women tend to have accelerated disc degeneration after menopause [9 – 12]. It has also been shown that lumbar disc narrowing is more common and more severe in elderly women than in elderly men, and this disparity increases as age advances [13]. With respect to gender specificity of lumbar disc T1rho, it would be interesting for Gübitz et al. to examine pre-menopausal female participants and post-menopausal female participants separately and compare them with their age-matched male counterparts. Even though the study participants in the study by Gübitz et al. did not have clinical symptoms associated with lumbar disc degeneration, it is still probable that a portion of them had disc degeneration in addition to physiological aging. Providing pooled data of normal subjects by excluding subjects with pathological disc degeneration will help to establish the appropriate normal range of discs at specific regions with respect to physiological aging. In one study composed of healthy volunteers and patients with mild nonspecific LBP, it was shown that on average women had an initially higher T2 value before the age of 50. This trend was reversed in elderly persons, with an intersection at 52.4 years [10]. However, it is still unclear whether menopause is associated with accelerated overall disc aging (as seen by a lowered T2 or T1rho value) or with a higher incidence of disc degeneration, or maybe both. Perhaps a re-analysis of the study by Gübitz et al. can shed some light on this question. A bigger population-based study will offer a more definitive answer.

3T MRI has become increasingly available for better imaging of interosseous ligaments, TFCC, and avascular necrosis compared with 1.5T MRI. This study assesses the sensitivity and specificity of 3T MRI compared with arthroscopy as the gold standard.

Abstract Purpose To assess the T1ρ range of lumbar intervertebral discs in healthy asymptomatic individuals at 1.5 T and to investigate the influence of age, body mass index (BMI), gender, and lumbar level on T1ρ relaxation. Materials and Methods In a prospective study, a total of 81 volunteers aged 20 – 80 years were included in this study and divided into three age groups (A: 20 – 39y; B: 40 – 59y; C: 60 – 80y). All of the volunteers underwent magnetic resonance imaging (MRI) at 1.5 T with acquisition of sagittal T1ρ images. The calculated T1ρ relaxation times were correlated with age, BMI, gender, and lumbar level relative to the total disc, the annulus fibrosus, and the nucleus pulposus. Results Age had a significant influence on T1ρ relaxation times at all lumbar levels, with increasing age being associated with reduced relaxation times. There was also a significant difference between age groups A vs. C and B vs. C (P = 0.0008 and P = 0.0149, respectively). No significant differences in T1ρ relaxation time were observed between men and women (P > 0.05). BMI showed a significant negative correlation with T1ρ relaxation times (P < 0.0001). Analysis of the lumbar level revealed a significant decrease in relaxation times from L1/2 to L5 / S1 (P = 0.0013). Conclusion Increasing age correlated significantly with advanced lumbar disc degeneration in asymptomatic individuals, particularly in those aged 60 or older. Increasing BMI correlated significantly with increasing degeneration. The lower discs showed more degeneration than the upper ones. Key Points Increasing age significantly reduces the T1ρ relaxation time in the intervertebral discs (P < 0.05) Gender does not significantly influence T1ρ relaxation times (P > 0.05) BMI shows a significant negative correlation with T1ρ relaxation times (P < 0.01) Significantly shorter relaxation times in lower lumbar spine vs. upper lumbar spine (P < 0.01) Citation Format Gübitz R, Lange T, Gosheger G et al. Influence of Age, BMI, Gender and Lumbar Level on T1ρ Magnetic Resonance Imaging of Lumbar Discs in Healthy Asymptomatic Adults. Fortschr Röntgenstr 2018; 190: 144 – 151

PURPOSE:To test at 1.5 T whether T1ρ magnetic resonance (MR) imaging of fibrotic liver disease is feasible, to investigate whether liver T1ρ imaging allows assessment of the severity of liver cirrhosis, and to assess the normal liver T1ρ range in healthy patients.MATERIALS AND METHODS:This prospective study was approved by the institutional ethics committee. Written informed consent was obtained. Healthy volunteers (n = 25) and patients (n = 34) with cirrhosis underwent whole-liver T1ρ MR imaging at 1.5 T. Mean T1ρ values were calculated from liver regions of interest. Mean T1ρ values were correlated to clinical data and histopathologic analysis by analysis of variance. Receiver operating characteristic curves were calculated to determine the accuracy of mean T1ρ values for the assessment of Child-Pugh class.RESULTS:Mean T1ρ values of volunteers (mean, 40.9 msec ± 2.9 [standard deviation]; range, 33.9-46.3 msec) were significantly lower than those of patients who were Child-Pugh class A (P < .004), B (P < .001), or C (P < .001), and significant differences were found between each Child-Pugh stage (A vs B, P < .002; B vs C, P < .009; A vs C, P < .001). Liver cirrhosis was confirmed via histologic analysis in all patients with liver biopsy. Mean T1ρ values did not correlate with necroinflammatory activity (r = 0.31; P = .23), degree of steatosis (r = -0.016; P = .68), or presence of iron load (r = 0.22; P = .43). Mean T1ρ values performed well by assessing the Child-Pugh stage, with receiver operating characteristic areas of 0.95-0.98. Intraclass correlation coefficient values ranged between 0.890 and 0.987, which indicated excellent imaging and reimaging reproducibility and interobserver and intraobserver variability.CONCLUSION:Whole-liver T1ρ MR imaging at 1.5 T to detect and assess human liver cirrhosis is feasible. Further investigation and optimization of this technique are warranted to cover the entire spectrum of fibrotic liver disease.

Rey’s Auditory Verbal Learning Test (AVLT) is widely used to evaluate dysfunctional episodic memory. The current study aimed to provide extended age- and gender-specific norms for the German AVLT for individuals older than 50 years. In 690 subjects, a comprehensive medical examination including a structural 3.0-tesla magnetic resonance imaging scan was administered, as well as extensive neuropsychological tests. After controlling for exclusion criteria, 407 subjects were included in the analysis. AVLT performance decreased with age, and women outperformed men. We present age- and gender-specific normative data for the German AVLT from subjects aged between 50 and 70 years.

Introduction Aneurysmal bone cysts (ABCs) are expansive and destructive lesions positive for osteoclast markers, resembling benign giant cell tumors (GCTs). Treatment options include surgical resection, curettage and cavity filling, embolization, injection of fibrosing agents, or radiotherapy. Particularly in children and adolescents with spinal ABCs, these options may be unsatisfactory, and innovative forms of treatment are needed. Denosumab is a human monoclonal antibody that inhibits osteoclast function by blocking the cytokine receptor activator of the nuclear factor-kappa B ligand. Satisfactory results with denosumab in treating GCTs and immunohistochemical similarities suggest that it may also have positive effects on ABCs. Methods and Results This report is the first description of the therapeutic use of denosumab in two patients with spinal ABCs. Two boys (aged 8 and 11) had recurrent ABCs at C5 after surgery with intralesional tumor resection. Treatment options were discussed by the interdisciplinary tumor board. Arterial embolization was attempted, but failed due to an absence of appropriate afferent arteries. After the families had received extensive information and provided written consent, denosumab therapy was initiated as an individualized treatment, despite the absence as yet of scientific evidence. After the start of denosumab therapy, both patients recovered from pain and neurologic symptoms significantly and are now in a healthy condition with no severe side effects. Magnetic resonance imaging check-ups after 2 or 4 months of denosumab treatment, respectively, showed tumor regression in both patients. Discussion Longer follow-up and clinical studies are warranted to establish the value of denosumab in the treatment of ABCs.

Aufgrund ihres seltenen Vorkommens gehört der Umgang mit bösartigen Knochentumoren nicht zum Arbeitsalltag der meisten Radiologen. Für die (Differential-)Diagnostik, das Staging, das Therapiemonitoring und die Nachsorge von Knochentumoren sind besondere Kenntnisse und Erfahrungen notwendig. Diese gilt es, zu kennen und umzusetzen.

Purpose: Standard knee MRI is performed under unloading (ULC) conditions and not much is known about changes of the meniscus, ligaments or cartilage under loading conditions (LC). The aim is to study the influence of loading of different knee structures at 3 Tesla (T) in subjects with osteoarthritis (OA) and normal controls.Materials and methods: 30 subjects, 10 healthy and 20 with radiographic evidence of OA (10 mild and 10 moderate) underwent 3 T MRI under ULC and LC at 50% body weight. All images were analyzed by two musculoskeletal radiologists identifying and grading cartilage, meniscal, ligamentous abnormalities. The changes between ULC and LC were assessed. For meniscus, cartilage and ligaments the changes of lesions, signal and shape were evaluated. In addition, for the meniscus changes in extrusion were examined. A multivariate regression model was used for correlations to correct the data for the impact of age, gender, BMI. A paired T-Test was performed to calculate the differences in meniscus extrusion.Results: Subjects with degenerative knee abnormalities demonstrated significantly increased meniscus extrusion under LC when compared to normal subjects (p = 0.0008-0.0027). Subjects with knee abnormalities and higher KL scores showed significantly more changes in lesion, signal and shape of the meniscus (80% (16/20) vs. 20% (2/10); p = 0.0025), ligaments and cartilage during LC.Conclusion: The study demonstrates that axial loading has an effect on articular cartilage, ligament, and meniscus morphology, which is more significant in subjects with degenerative disease and may serve as an additional diagnostic tool for disease diagnosis and assessing progression in subjects with knee OA. (c) 2011 Elsevier Ireland Ltd. All rights reserved.

Purpose: The relationship of physical activity with the development of osteoarthritis remains unclear. The purpose of this study was to investigate the association between physical activity levels and early degenerative cartilage changes at the knee, measured using T2 relaxation times over a period of 4 years using 3 Tesla (3T). Materials and Methods: 152 subjects without radiographic or symptomatic knee osteoarthritis were randomly selected from the Osteoarthritis Initiative (OAI) database. The inclusion criteria included 45-60 years of age, BMI of 19-27 kg/ m2, and no knee pain in either knee (WOMAC score of zero), and a Kellgren-Lawrence (KL) score less than 2 in the right knee at baseline. The Physical Activity Scale for the Elderly (PASE) was completed at the initial visit and was used to categorize individuals into quartiles (Q1, Q2, Q3, Q4). T2 of articular cartilage in different locations in the knee was measured from multi-echo SE, a sequence acquired in the right knee of each individual from baseline and 48-month follow-up visits. Multiple linear regression models were used to adjust for age, gender, and BMI to determine the association between physical activity level and progression of knee T2 relaxation time. Results: Very high (Q4) and very low (Q1) physical activity levels were associated with higher T2 progression than a mid-level of physical activity (Q3) in the lateral femur (p = 0.025, p = 0.032, respectively). In the medial femur, very high levels of physical activity (Q4) were associated with higher T2 progression than a mid-level of physical activity (Q3, p = 0.015), while differences over lower levels of physical activity (Q2, Q3) trended toward significance (p = 0.084, p = 0.098, respectively). Conclusion: Very high levels of physical activity, as measured by PASE, were associated with higher progression of knee T2 values in the lateral and medial femur. Low levels of physical activity were associated with higher progression in the lateral femur. This suggests that both very low levels of physical activity and high levels of physical activity may predispose asymptomatic, middle-aged individuals to increased biochemical changes suggestive of cartilage degradation over time. These findings need to be confirmed in other cohorts and using objective measures of physical activity.

We assessed the relationship between cartilage MR relaxation times and biomechanical response of tibiofemoral articular cartilage to physiological loading in healthy subjects and patients with osteoarthritis (OA). Female subjects above 40 years of age with (N1 = 20) and without (N2 = 10) OA were imaged on a 3T MR scanner using a custom made loading device. MR images were acquired with the knee flexed at 20° with and without a compressive load of 50% of the subject's bodyweight. The subjects were categorized based on the clinical MRI scoring of medial and lateral cartilage surfaces. Data were stratified twice into two equal groups (low and high) at the median value of T1ρ and T2 relaxation time. The change in contact area and cartilage deformation was measured within these groups. Paired Student's t‐test (α = 0.05) was used to analyze the effect of loading on contact area and deformation. The average area of the contact region in the medial compartment was significantly higher in OA subjects compared with normal subjects in both unloaded (314 ± 112 mm2 vs. 227 ± 106 mm2, p = 0.023) and loaded (425 ± 128 mm2 vs. 316 ± 107 mm2, p = 0.01) conditions. The overall relative change of cartilage thickness in the medial compartment was significantly higher than the lateral compartment (−5.3 ± 9.9% vs. −1.9 ± 9.2%, p = 0.042). When cartilage was divided into deep and superficial layers, superficial layers showed higher changes in relaxation time (T1ρ and T2) than the changes in relaxation time of whole cartilage (Normal: 12.5% vs. 6.9%; OA: 10.9% vs. 4.6%). The average T1ρ and T2 times, change in area of contact region, and change in cartilage thickness in subjects with OA were higher when compared to normal subjects. This study provides support for a relationship between the mechanical response of cartilage to physiological loading (cartilage‐on‐cartilage contact area and cartilage deformation) and MR relaxation times (T1ρ and T2) in both OA patients and normal subjects. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:919–926, 2012

Purpose: To examine the changes in knee cartilage T2 values over 24 months in subjects with and without risk factors for knee osteoarthritis (OA) and their association with focal knee lesions at baseline.Materials and Methods: Forty-one subjects without and 101 subjects with OA risk factors (such as history of knee injury or surgery) were selected from the Osteoarthritis Initiative database (age: 45-55 years, no radiographic OA in the right knee). Baseline magnetic resonance imaging (MRI) of the right knee were assessed for prevalence and grade of focal knee lesions. Right knee cartilage T2 measurements were performed in five compartments (patella, medial/lateral femur/tibia) at baseline and at 24-month follow-up.Results: Compared to subjects without OA risk factors, those with OA risk factors showed no significant differences in baseline prevalence and grade of focal knee lesions (P >.05), but had significantly higher T2 values in the medial femur compartment at both timepoints (P < 0.05). T2 values averaged over all five compartments increased significantly over 24 months in both groups, but differences in T2 increase between the groups were not significant. Subjects with cartilage lesions showed significantly higher T2 values compared to subjects without cartilage lesions at both timepoints, but no accelerated T2 increase over 24 months (P > 0.05).Conclusion: Cartilage T2 values significantly increased over 24 months in subjects with and without OA risk factors, but neither the presence of OA risk factors nor the presence of cartilage lesions at baseline were associated with these T2 increases.

Individual differences in executive functioning and brain morphology are considerable. In this study, we investigated their interrelation in a large sample of healthy older individuals. Digit span, trail‐making, and Stroop tasks were used to assess different executive subfunctions in 367 nondemented community‐dwelling individuals (50–81 years). Task performance was analyzed relative to brain structure using voxel‐based morphometry, corrected for age and sex. Improved task performance was associated with increased local gray matter volume in task‐specific patterns that showed partial, but not complete overlap with known task‐specific functional imaging patterns. While all three tasks showed associations with prefrontal gray matter volume as expected for executive functioning, the strongest overlap between the three tasks was found in insular cortex, suggesting that it has a previously underestimated role for executive functions. The association between the insular cortex and executive functioning was corroborated using stereological region‐of‐interest measurement of insular volume in a subgroup of 93 subjects. Quantitatively, the volume of the single most strongly related region explained 2.4 ± 1.1% of the variance in executive performance over and above the variance explained by age, which amounted to 7.4 ± 4.1%. The age‐independent peak associations between executive performance and gray matter described here occurred in regions that were also strongly affected by age‐related gray matter atrophy, consistent with the hypothesis that age‐related regional brain volume loss and age‐related cognitive changes are linked. Hum Brain Mapp 34:3333–3346, 2013. © 2012 Wiley Periodicals, Inc.

Regional decreases in grey matter volume as detected by magnetic resonance imaging-based volumetry have been reported in several clinical chronic pain cohorts. Here, we used voxel-based morphometry in a nonclinical cohort to investigate whether grey matter alterations also occur in older individuals (aged 40-85 years) from the general population. Based on self-report of pain, we identified 31 pain-free controls, 45 subjects with ongoing pain (low back pain, headache, or lower extremity joint pain) who had at least moderate pain on more than 3 days/month, and 29 individuals with past pain (stopped for >12 months). Relative to controls, the ongoing pain group showed regional grey matter volume decreases, predominantly in cingulate, prefrontal, and motor/premotor regions. No grey matter volume decreases were found in the group with pain that had stopped for >12 months. These results show that pain-related grey matter volume decreases are present in individuals from the general population. The lack of morphometric anomalies in subjects with past pain supports recent evidence suggesting that pain-related grey matter changes are reversible after cessation of pain.

To prospectively evaluate changes in T1rho and T2 relaxation time in the meniscus using 3.0 T MRI in asymptomatic knees of marathon runners and to compare these findings with those of age-matched healthy subjects.Thirteen marathon runners underwent 3.0 T MRI including T1rho and T2 mapping sequences before, 48-72 h after, and 3 months after competition. Ten controls were examined at baseline and after 3 months. All images were analyzed by two musculoskeletal radiologists identifying and grading cartilage, meniscal, ligamentous. and other knee abnormalities with WORMS scores. Meniscal segmentation was performed to generate T1rho and T2 maps in six compartments.No differences in morphological knee abnormalities were found before and after the marathon. However, all marathon runners showed a significant increase in T1rho and T2 values after competition in all meniscus compartments (p < 0.0001), which may indicate changes in the biochemical composition of meniscal tissue. While T2 values decreased after 3 months T1rho values remained at a high level, indicating persisting changes in the meniscal matrix composition after a marathon.T2 values in menisci have the potential to be used as biomarkers for identifying reversible meniscus matrix changes indicating potential tissue damage. T1rho values need further study, but may be a valuable marker for diagnosing early, degenerative changes in the menisci following exercise.

PURPOSE: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.MATERIALS AND METHODS: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.RESULTS: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.CONCLUSION: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.

OBJECTIVETo 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.METHODSWe 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.RESULTSAmong 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.CONCLUSIONIn 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.

Ziele: T2 Relaxationsmessungen sind ein vielversprechender quantitativer Marker für die Beurteilung von degenerativen Gelenkerkrankungen. Die Segmentierung des Knieknorpels ist jedoch sehr zeitintensiv. Es könnte von großem Vorteil sein nur ein Kompartiment zu segmentieren, welches die allgemeine Pathologie wiederspiegelt. Das Ziel dieser Studie ist zu untersuchen, welches Kompartiment am Besten mit morphologischen Knieabnormaltäten korreliert. Methode: Die OAI ist eine longitudinale Multizenterstudie für Kniearthrose. Eine Subgruppe von 217 asymptomatische Personen (Alter 45–55) mit mittlerem BMI wurden bei 3 Tesla untersucht (mit protonengewichteten Spin-Echo und T2 mapping Sequenzen). Alle Bilder wurden von 2 Radiologen analysiert und der Grad der Knorpel- und Meniskusläsionen, Osteophyten, Knochenmarködeme und Gelenkergüsse mithilfe des sog. WORMS Scores bestimmt. Der Knieknorpel wurde segmentiert und T2 Maps für erstellt. Diese Werte wurden mit den Knieveränderungen korreliert. Statistische Signifikanzen wurden mithilfe eines Multiregressionsmodels bestimmt. Ergebnis: Die mittleren T2 Werte zeigten eine große Korrelation zur Prävalenz von verschiedenen Kniepathologien wie Gelenkergüsse (p=0,006) und Knorpel- (0,039) und Meniskusveränderungen (p=0,044). Vergleicht man alle 6 Kniekompartimente so zeigen die T2 Werte des medialen Femurkondylus die höchsten Korrelationen mit den mittleren WORMS Scores der verschiedenen Kniepathologien, wie Knorpelläsionen (p<0,0001), Meniskusläsionen (p=0,004), Osteophyten (p=0,0002), Knochenmarködemen (p=0,011) und Gelenkergüsse (p=0,006). Schlussfolgerung: Vergleicht man die 6 Kniekompartimente zeigte der mediale Femurkondylus die besten Korrelationen mit den verschieden Kniepathologien und ist somit das beste Kompartiment zur Evaluierung des Ausmaßes der Kniegelenksdegeneration.

Magnetic resonance imaging (MRI) T-2 relaxation time assesses non-invasively cartilage composition and can be used as early biomarker for knee osteoarthritis. Most knee cartilage segmentation techniques were primarily developed for volume measurements in DESS or SPGR sequences. For T-2 quantifications, these segmentations need to be superimposed on T-2 maps. However, given that these procedures are time consuming and require manual alignment, using them for analysis of T-2 maps in large clinical trials like the Osteoarthritis Initiative (OAI) is challenging.A novel direct segmentation technique (DST) for T-2 maps was therefore developed. Using the DST, T-2 measurements were performed and compared with those determined with an established segmentation superimposition technique (SST). MR images of five OAI participants were analysed with both techniques three times by one reader and five different images sets additionally with DST three times by two readers.Segmentations and T-2 measurements of one knee required on average 63 +/- 3 min with DST (vs 302 +/- 13 min for volume and T-2 measurements with SST). Bland-Altman plots indicated good agreement between the two segmentation techniques, respectively the two readers. Reproducibility errors of both techniques (DST vs SST) were similar (P>0.05) for whole knee cartilage mean T-2 (1.46% vs 2.18%), laminar (up to 2.53% vs 3.19%) and texture analysis (up to 8.34% vs 9.45%). Inter-reader reproducibility errors of DST were higher for texture analysis (up to 15.59%) than for mean T-2 (1.57%) and laminar analysis (up to 2.17%). Due to these results, the novel DST can be recommended for T-2 measurements in large clinical trials like the OAI. (C) 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Objective: To study the role of vastus lateralis/vastus medialis cross-sectional area CSA ratio (VL/VM CSA ratio) in preclinical knee osteoarthritis (OA) using magnetic resonance imaging (MRI)-based cartilage 12 mapping technique and morphological analysis at 3.0T in non-symptomatic, middle-aged subjects.Material and methods: 174 non-symptomatic individuals aged 45-55 years with OA risk factors were selected from the Osteoarthritis Initiative (OAI) incidence cohort. OA-related knee abnormalities were analyzed using the whole-organ magnetic resonance imaging score (WORMS). Knee cartilage T2 maps were generated using sagittal 2D multi-echo spin-echo images of the right knee. CSA of thigh muscles was measured using axial T1W images of the right mid thigh. Spline-based segmentation of cartilage and muscles was performed on a SUN/SPARC workstation. Muscle measurements were normalized to body size using body surface area (BSA). Statistical significance was determined using Student's t-test, Pearson correlation test, and multiple regression models. To correct for multiple testing, Bonferroni adjustments were applied across all tests within each of the primary results tables (Tables III-VII).Results: Higher 12 values were associated with increased prevalence and severity of cartilage degeneration. In our study, male and female subjects with higher VL/VM CSA ratio demonstrated significantly lower mean cartilage 12 values (all compartments combined) (mean 44.10 vs 45.17, P = 0.0017), and significantly lower WORMS scores (mean 14.12 vs 18.68, P= 0.0316). Regression analyses of combined mean cartilage 12 using VL/VM CSA ratio as a continuous predictor showed a significant curvilinear relationship between these two variables (P = 0.0082).Conclusion: Our results suggested that higher VL/VM CSA ratio is associated with lower T2 values and decreased presence and severity of OA-related morphological changes. Additional studies will be needed to determine causality. (C) 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.