T1 Mapping Research Articles

Single bundle vs double bundle for anterior cruciate ligament reconstruction evaluated with T2 mapping: A case series

Single bundle vs double bundle for anterior cruciate ligament reconstruction evaluated with T2 mapping: A case series

Use of multiparametric MRI to noninvasively assess iodinated contrast-induced acute kidney injury

PurposeTo gauge the utility of multiparametric MRI in characterizing pathologic changes after iodinated contrast-induced acute kidney injury (CI-AKI) in rats. MethodsWe randomly grouped 24 rats injected with 8 g iodine/kg of body weight (n = 6 each) and 6 rats injected with saline as controls. All rats underwent T1, T2 mapping and diffusion kurtosis imaging (DKI) after contrast injection at 0 (control), 1, 3, 7, 13 days. T1, T2, and mean kurtosis (MK) values were performed in renal outer/inner stripes of outer medulla (OSOM and ISOM) and cortex (CO), and their diagnosis performance for CI-AKI also been evaluated. Serum creatinine (SCr), insulin-like growth factor-binding protein 7 (IGFBP7), tissue inhibitor metalloproteinase 2 (TIMP-2), aquaporin-1 (AQP1), α-smooth muscle actin (α-SMA), and histologic indices were examined. ResultsCompared with controls, urinary concentrations of both TIMP-2 and IGFBP7 were obviously elevated from Day 1 to Day 13 (all p < 0.05). T2 values were significantly higher than control group for Days 1 and 3, and T1 and MK increased were more remarkable at all time points (Days 1–13) in CI-AKI (all p < 0.05) than control group. Changes in T1 and MK strongly correlated with renal injury scores of all anatomical compartments and with expression levels of AQP1 and moderately correlated with α-SMA. Changes in T2 values correlating moderately with renal scores of CO, ISOM and OSOM and AQP1. The MK obtained the highest area under the receiver operating characteristic (ROC) curve of 0.846 with a sensitivity of 70.8 % and specificity of 88.9 %. ConclusionsCombined use of multiparametric MRI could be a valid noninvasive method for comprehensive monitoring of CI-AKI. Among these parameters, MK may achieve the best diagnostic performance for CI-AKI.

Deep Learning Virtual Contrast-Enhanced T1 Mapping for Contrast-Free Myocardial Extracellular Volume Assessment.

The acquisition of contrast-enhanced T1 maps to calculate extracellular volume (ECV) requires contrast agent administration and is time consuming. This study investigates generative adversarial networks for contrast-free, virtual extracellular volume (vECV) by generating virtual contrast-enhanced T1 maps. This retrospective study includes 2518 registered native and contrast-enhanced T1 maps from 1000 patients who underwent cardiovascular magnetic resonance at 1.5 Tesla. Recent hematocrit values of 123 patients (hold-out test) and 96 patients from a different institution (external evaluation) allowed for calculation of conventional ECV. A generative adversarial network was trained to generate virtual contrast-enhanced T1 maps from native T1 maps for vECV creation. Mean and SD of the difference per patient (ΔECV) were calculated and compared by permutation of the 2-sided t test with 10 000 resamples. For ECV and vECV, differences in area under the receiver operating characteristic curve (AUC) for discriminating hold-out test patients with normal cardiovascular magnetic resonance versus myocarditis or amyloidosis were tested with Delong's test. ECV and vECV showed a high agreement in patients with myocarditis (ΔECV: hold-out test, 2.0%±1.5%; external evaluation, 1.9%±1.7%) and normal cardiovascular magnetic resonance (ΔECV: hold-out test, 1.9%±1.4%; external evaluation, 1.5%±1.2%), but variations in amyloidosis were higher (ΔECV: hold-out test, 6.2%±6.0%; external evaluation, 15.5%±6.4%). In the hold-out test, ECV and vECV had a comparable AUC for the diagnosis of myocarditis (ECV AUC, 0.77 versus vECV AUC, 0.76; P=0.76) and amyloidosis (ECV AUC, 0.99 versus vECV AUC, 0.96; P=0.52). Generation of vECV on the basis of native T1 maps is feasible. Multicenter training data are required to further enhance generalizability of vECV in amyloidosis.

The Role of Perfusion Magnetic Resonance Imaging in the Discrimination of Benign vs Malign Character of Musculoskeletal Tumors

Purpose: There may be difficulties in diagnosing musculoskeletal system tumors with Magnetic Resonance Imaging (MRI). Advanced MRI imaging techniques may contribute to noninvasive diagnosis.The aim of our study was to evaluate the performance of perfusion magnetic resonance imaging quantitative data in the differentiation of benign and malignant musculoskeletal tumors. Material and Methods: Thirty-six histologically proven patients were included in the study retrospectively. All patients underwent 1.5-T perfusion MRI (magnetic resonance imaging) with T1 mapping and diffusion MRI. Four quantitative and one semiquantitative parameter were obtained for each tumor using the Toft pharmacokinetic model. ADCmean and ADCmin values were calculated from apparent diffusion coefficient (ADC) maps. Results: Eighteen of 36 patients (50%) had malignant tumors, and 18 had benign tumors. There were 26 soft tissue tumors and 10 bone tissue tumors. Among malignant and benign tumors, the best performance was found in the Ktrans, Kep, Ve values. (p=0.011, p=0.013, p=0,035). Conclusion: Ktrans and Kep values, which are indicators of increased permeability in the tumor, are noninvasive parameters for determining the malignant character of the tumor. The 'Ve' value is an indicator of the extracellular volume of the tumor. Ktrans, Kep and Ve maps can also guide the biopsy.

Subclinical Myocardial Fibrosis in South African Youth With HIV: Results From the CTAAC-Heart Study

Abstract Background Few data exist on myocardial fibrosis and inflammation in youth with HIV. Methods We performed cardiovascular magnetic resonance (CMR) on a cross section of South African youth: youth with perinatally acquired HIV (YPHIV) undergoing antiretroviral therapy (ART), youth with nonperinatally acquired HIV (YNPHIV) receiving ART, and youth without HIV. Quantile regression models were fit to assess the association between HIV status and CMR outcomes: subclinical fibrosis (late gadolinium enhancement [LGE] mass and fraction, native T1, extracellular volume) and inflammation (native T1, T2 mapping). Results Of 464 youth, 287 were YPHIV, 87 were YNPHIV, and 90 were HIV seronegative. The median age was 16 years (range, 11–24). LGE mass was higher in YPHIV and YNPHIV than in youth who were HIV seronegative (1.85 vs 2.00 vs 1.41 g, respectively), as was fraction (5.8% vs 6.4% vs 4.5%); native T1 was highest in YNPHIV. In adjusted analyses, when compared with youth with HIV seronegativity, YPHIV and YNPHIV exhibited higher LGE mass (β = 0.468, P = .001; β = 0.544, P = .002) and LGE fraction (β = 1.587, P &amp;lt; .001; β = 1.781, P &amp;lt; .001). CMR outcomes were similar between YPHIV and YNPHIV. Conclusions Despite ART use, YPHIV and YNPHIV appear to have higher subclinical myocardial fibrosis than youth who are HIV seronegative and healthy adults in South Africa and may benefit from early screening/monitoring for cardiovascular disease.

The additional value of myocardial T1ρ mapping to T1 and T2 mapping for predicting subsequent cancer therapy-related cardiac dysfunction in breast cancer patients who received anthracyclines with/without trastuzumab

ObjectivesWe aimed to describe changes in parameters derived from myocardial T1ρ, T1, and T2 mapping and assess whether incorporating T1ρ mapping improves the predictive performance of T1 and T2 mapping for subsequent cancer therapy-related cardiac dysfunction (CTRCD) in breast cancer patients treated with anthracyclines with/without trastuzumab. MethodsFrom March 2021 to May 2023, 82 participants with breast cancer treated with anthracyclines with/without trastuzumab were prospectively recruited. Cardiac magnetic resonance was performed at baseline, 3 and 6 months in relation to baseline. T1ρ, T1 and T2 values were measured and compared by repeated measures analyses of variance. Logistic regression and receiver operating characteristic analysis were used to assess the performance in predicting subsequent CTRCD. ResultsNineteen (23.17 %) participants developed CTRCD. T1ρ and T1 values progressively increased over time (all p < 0.001), while T2 values increased at 3 (p < 0.001 and p = 0.002, respectively) and 6 months (all p < 0.001) compared to baseline in both the CTRCD (+) and CTRCD (−) groups. The changes in T1ρ (OR, 3.892, p = 0.003) and T1 (OR, 1.082, p = 0.002) from baseline to 3 months were associated with subsequent CTRCD. The combination of the changes in T1ρ and T1 from baseline to 3 months obtained an improved area under the curve of 0.853. ConclusionT1ρ, T1 and T2 increased after treatment of anthracyclines with/without trastuzumab. Myocardial T1ρ mapping provides additional predictive value to T1 mapping for subsequent CTRCD in breast cancer patients who received anthracyclines with/without trastuzumab. Clinical relevance statementMyocardial T1ρ mapping offers additional predictive value to T1 and T2 mapping for subsequent CTRCD in breast cancer patients who received anthracyclines with/without trastuzumab. This may facilitate accurate prediction of cardiotoxicity and personalized treatment decision making in breast cancer.

CMR native T1 and T2 Mapping in Olympic athletes: the influence of sport discipline and sex

Abstract Background Cardiac Magnetic Resonance (CMR) has a growing role in evaluating athletes’ hearts. Mapping techniques provide added value for tissue characterisation, but data on athletes and sports disciplines are lacking. Aim To describe native mapping values in a cohort of Olympic Athletes and evaluate the influence of sports discipline and sex. Methods A group of 300 Olympic athletes (13% skill, 20% power, 25% mixed, 42% endurance, 58% male) with unremarkable cardiovascular screening and a control group of 42 sedentary subjects (52% male) underwent CMR without contrast administration. Athletes were divided based on sex and sports categories according to the ESC classification. Results Among athletes of different sports categories and controls, endurance presented the lowest value of T1 mapping (p&amp;lt;0.001). No differences in T2 mapping were observed (p=0.472). Female athletes had higher values of T1 native myocardial mapping compared to males (p=0.001), while there were no differences in T2 mapping (p=0.817). Male athletes with higher left ventricular mass indexed (LV-Massi) had lower values of T1 mapping (p=0.006) and slightly higher values of T2 mapping, even if not significant (p=0.150). Female athletes with higher LV-Massi did not show significant differences in T1 and T2 mapping (p=0.053 and p=0.438) Conclusions T1 native myocardial mapping showed significant differences related to sports disciplines and gender. Athletes with the largest LV remodelling, mostly endurance and mixed, showed the lowest values of T1 mapping. Male athletes showed lower values of T1 mapping than females. No significant differences were observed in T2 mapping related to sports disciplines and gender.

Performance of MR learned pulse sequences for 3D bi-exponential, stretched-exponential, and mono-exponential T2 and T1ρ mapping of knee cartilage.

To compare the performance of a learned magnetization-prepared gradient echo (L-MPGRE) sequence against a commonly used sequence for 3D T2 and T1ρ mapping of the knee joint, the magnetization-prepared angle-modulated partitioned k-space spoiled gradient echo snapshots (MAPSS), on bi-exponential (BE), stretched-exponential (SE), and mono-exponential (ME) relaxation models. We used a combined differentiable and non-differentiable optimization to learn pulse sequence structure and its parameters for 3D T2 and T1ρ mapping of the knee joint using ME, SE, and BE models. The learned pulse sequence framework was used to improve quantitative accuracy and SNR and to reduce filtering effects. We compare the measured multi-compartment values between the two sequences (n = 8), and their repeatability (n = 4) in healthy volunteers (n = 12 total). The voxel-wise median absolute percentage difference (MAPD) between the T2 and T1ρ maps obtained with each sequence was 18.6% and 19.9%, respectively. The T2 and T1ρ repeatability tests showed a MAPD of 18.5% and 19.1% for MAPSS, and 16.8% and 15.5% for L-MPGRE. Bland-Altman region of interest (ROI)-wise analysis shows that bias is small, close to -1.5%, and the coefficient of variation is around 5.5% when comparing ROIs from both sequences. The L-MPGRE sequences can be used as a replacement for MAPSS for T2 and T1ρ mapping in the knee cartilage with advantages, achieving similar accuracy and 15% better repeatability in only half of its scan time.

Distribution of MRI-derived T2 values as a biomarker for in vivo rapid screening of phenotype severity in mdx mice

Background The pathology in Duchenne muscular dystrophy (DMD) is characterized by degenerating muscle fibers, inflammation, fibro-fatty infiltrate, and edema, and these pathological processes replace normal healthy muscle tissue. The mdx mouse model is one of the most commonly used preclinical models to study DMD. Mounting evidence has emerged illustrating that muscle disease progression varies considerably in mdx mice, with inter-animal differences as well as intra-muscular differences in pathology in individual mdx mice. This variation is important to consider when conducting assessments of drug efficacy and in longitudinal studies. We developed a magnetic resonance imaging (MRI) segmentation and analysis pipeline to rapidly and non-invasively measure the severity of muscle disease in mdx mice. Methods Wildtype and mdx mice were imaged with MRI and T2 maps were obtained axially across the hindlimbs. A neural network was trained to rapidly and semi-automatically segment the muscle tissue, and the distribution of resulting T2 values was analyzed. Interdecile range and Pearson Skew were identified as biomarkers to quickly and accurately estimate muscle disease severity in mice. Results The semiautomated segmentation tool reduced image processing time approximately tenfold. Measures of Pearson skew and interdecile range based on that segmentation were repeatable and reflected muscle disease severity in healthy wildtype and diseased mdx mice based on both qualitative observation of images and correlation with Evans blue dye uptake. Conclusion Use of this rapid, non-invasive, semi-automated MR image segmentation and analysis pipeline has the potential to transform preclinical studies, allowing for pre-screening of dystrophic mice prior to study enrollment to ensure more uniform muscle disease pathology across treatment groups, improving study outcomes.

Meta-analysis of cardiac magnetic resonance in prognosticating left ventricular function in peripartum cardiomyopathy.

Peripartum cardiomyopathy (PPCM) may result in a number of detrimental adverse cardiovascular events, notably persistent left ventricular ejection fraction (LVEF) reduction or even mortality. Imaging parameters on cardiac magnetic resonance (CMR) and their prognostic implications have rarely been perused in PPCM. We aimed to describe CMR's prognostic value in predicting poor left ventricular (LV) function recovery using late gadolinium enhancement (LGE) and T2-weighted or T2 mapping. PubMed, Europe PMC, and ScienceDirect were screened for studies on late gadolinium enhancement (LGE) and myocardial oedema using CMR and PPCM. The outcome of interest was poor LV function recovery, with a follow-up period of at least 6months. Comparisons between groups with the presence of LGE, myocardial oedema, and recovered against non-recovered patients were pooled. A random-effects model was employed to calculate the effect size. All pooled results were expressed as risk ratios (RRs) and 95% confidence intervals (CI). The area under the curve (AUC) was generated to test overall prognostic accuracy. Six cohort studies with 162 patients were included. The mean age of participants in this study was 30.6years, and the majority of patients were diagnosed with PPCM after delivery. LGE was associated with a higher risk of poor LV function recovery, particularly when conducted at a later stage of disease (≥2.8months) [RR=2.83 (95% CI=1.25-6.40); P=0.001]. On the contrary, CMR conducted early (<2.8months) exhibited a greater predictive value for myocardial oedema perceived by T2 mapping [RR=3.44 (95% CI=1.04-11.34); P=0.043]. Diagnostic-test accuracy meta-analysis revealed that LGE had a sensitivity of 73% (95% CI, 56-85%), specificity of 79% (95% CI, 45-95%), and AUC of 0.78 (95% CI, 0.75-0.82) in predicting poor LV recovery when performed in the later phase, whereas significant myocardial oedema in those with non-recovered LV function had a sensitivity of 12% (95% CI, 2-52%), specificity of 68% (95% CI, 39-88%), and AUC of 0.40 (95% CI, 0.36-0.44) while undertaken in the latter phase. Our findings support the notion that inflammation plays a significant role in PPCM and that alterations to tissue composition occur in a time-dependent manner. Contrast-enhanced CMR can be utilized as an adjunct examination in post-partum PPCM patients to stratify the risk of poor LV function recovery while conducted at a suitable point in time.

Comparative Study Between Variable Flip Angle and Modified Look-Locker Inversion Recovery for Evaluating Renal Interstitial Fibrosis.

Variable flip angle (VFA) and modified Look-Locker inversion recovery (MOLLI) are frequently used for noninvasive evaluation of renal interstitial fibrosis (IF) in chronic kidney disease (CKD). However, controversy remains over which method is preferred. To compare the diagnostic efficacy of VFA and MOLLI for T1 mapping in evaluating renal IF. Prospective. Fifty-one participants with CKD (CKD stage 1-5, 35 males) and 18 healthy volunteers (eight males). 3.0 T, three-dimensional gradient echo sequence for B1+ VFA, and two-dimensional gradient echo sequence for MOLLI. Image quality was assessed on a five-point scale. Cortex and medulla T1 values (cT1 and mT1), corticomedullary T1 value difference (ΔT1, medulla - cortex), and corticomedullary T1 value ratio (ratio T1, cortex:medulla) were compared between VFA and MOLLI as well as between IF grade (0-4) based on biopsy. Intraclass correlation coefficient, Bland-Altman analysis, analysis of variance, Kruskal-Wallis test, correlation analysis, and receiver operating characteristics analysis with the area under the curve (AUC). P-value <0.05 was considered significant. MOLLI provided significantly better image quality compared to VFA. cT1 and mT1 values significantly differed between VFA and MOLLI (cT1-VFA: 1771.4 ± 139.4 msec vs. cT1-MOLLI: 1729.9 ± 132.1 msec; mT1-VFA: 2076.0 [interquartile range (IQR): 2045.9-2129.9] msec vs. mT1-MOLLI: 2039.2 [IQR: 1997.8-2071.6] msec). ΔT1 and ratio T1 values were not different between VFA and MOLLI (ΔT1: 300.8 ± 71.4 vs. 306.0 ± 78.4, respectively, P = 0.33 and ratio T1: 0.85 ± 0.038 vs. 0.85 ± 0.041, respectively, P = 0.064). No difference was observed between T1 variables and T1 mapping methods in diagnosing IF. ΔT1 and ratio T1 were not different between VFA and MOLLI. Both VFA and MOLLI are effective for noninvasive assessment of renal IF. 2 TECHNICAL EFFICACY: Stage 2.

Bone marrow edema-like signal after cartilage repair does not affect outcomes in a five-year follow-up.

Bone marrow edema-like signal (BMELS) after cartilage repair is common, but its clinical significance remains uncertain. This study aimed to investigate the clinical and structural significance of BMELS following microfracturing (MFX) and matrix-induced autologous chondrocyte implantation (MACI). In this multicenter study, MRI examinations were performed over a period of 5 years after cartilage repair surgery (MFX n = 17; MACI n = 28) in 45 patients. Morphological assessments, including the MOCART 2.0 (magnetic resonance observation of cartilage repair tissue), quantitative imaging biomarkers (QIB) with T2 mapping of the repair tissue, and, specifically, assessment of the presence and size of BMELS, were conducted along with patient-reported outcome measures, such as the Knee injury and Osteoarthritis Outcome Score (KOOS) and the International Knee Documentation Committee (IKDC). BMELS structural and clinical assessments were obtained after 3 months, 12 months, and 60 months. Statistical analysis included the Mann-Whitney U-test, Wilcoxon rank test, Shapiro-Wilk test, and simulation-based power analysis. BMELS were a common finding 60 months after cartilage repair. The size of BMELS differed significantly only between MACI and MFX patients after 3 months, with larger BMELS occurring in the MFX group. There were no significant differences in patients with or without BMELS regarding the T2 ratio of the treated area, the MOCART 2.0, or clinical scores. BMELS frequently appeared after cartilage repair procedures. We could show that the postoperative size and change in the size of BMELS after MACI and MFX did not affect clinical scores, morphological MRI results, or biochemical properties of the treated area after 60 months. Question What is the clinical significance of bone marrow edema-like signal (BMELS) appearance after matrix-induced autologous chondrocyte implantation (MACI) or microfracture (MFX)? Finding There were no significant differences in patients with or without BMELS regarding the T2 ratio of the treated area, the MOCART 2.0, or clinical scores. Clinical relevance BMELS frequently appeared after cartilage repair, the appearance or the size dynamic after MACI and MFX did not affect clinical scores, morphological MRI results, or biochemical properties after 60 months.

MRI quantitative T1 and T2 mapping of the renal cortex: Assessment of normal values and potential usefulness for renal masses at 3 T

PurposeThe purpose of this monocentric retrospective study consisted in exploring the potential improvement of the assessment of renal masses on MRI by using the T1 (T1m) and T2 (T2m) mapping relaxation times. Materials and MethodsWe recorded the renal cortex values of 125 patients with normal kidneys (reference group) and 75 patients with renal masses on a clinical 3 T MR unit using T1m and T2m sequences.For the quantitative evaluation, measurements were performed by delineating ROIs on T1m and T2m sequences in renal cortex of the reference group and in renal masses.Interobserver agreement for the qualitative analysis of image quality was assessed using quadratic Cohen’s weighted kappa statistics (k).Student’s paired t-test and non-parametric Kruskal-Wallis test were used to compare our datasets in terms of T1m and T2m values. ResultsFor the cohort of reference group, mean renal cortex T1m and T2m values were 1,529 ± 83 ms and 98 ± 7 ms, respectively. No statistically significant differences were found for T1m and T2m in the reference group regardless of age, gender or eGRF categories.For the group with renal masses, mean T1m and T2m values were 1,667 ± 87 ms and 105 ± 8 ms; 1,621 ± 96 ms and 117 ± 6 ms, and 1,530 ± 62 ms and 85 ± 4 ms for renal cell carcinomas, angiomyolipomas, and oncocytomas, respectively. For T1m values, there was no significant difference (p = 0.37) among the three types of renal masses. Among histological subtypes we have found: RCC versus angiomyolipoma (p = 0.25), RCC versus oncocytoma (p = 0.15), and oncocytoma versus angiomyolipoma (p = 0.47).However, we have found a statistically significant difference for the T2m value (p = 0.0005). Among histological subtypes, only T2m values were statistically significant for each combination: RCC versus angiomyolipoma (p = 0.012), RCC versus oncocytoma (p = 0.0002), and oncocytoma versus angiomyolipoma (p = 0.003). ConclusionAs this is the largest normal patient cohort, the T1m and T2m values recorded could be proposed as reference values and can play a role in the differential diagnosis between benign and malignant renal tumoral masses.

Accelerated model-based T1, T2* and proton density mapping using a Bayesian approach with automatic hyperparameter estimation.

To achieve automatic hyperparameter estimation for the model-based recovery of quantitative MR maps from undersampled data, we propose a Bayesian formulation that incorporates the signal model and sparse priors among multiple image contrasts. We introduce a novel approximate message passing framework "AMP-PE" that enables the automatic and simultaneous recovery of hyperparameters and quantitative maps. We employed the variable-flip-angle method to acquire multi-echo measurements using gradient echo sequence. We explored undersampling schemes to incorporate complementary sampling patterns across different flip angles and echo times. We further compared AMP-PE with conventional compressed sensing approaches such as the -norm minimization, PICS and other model-based approaches such as GraSP, MOBA. Compared to conventional compressed sensing approaches such as the -norm minimization and PICS, AMP-PE achieved superior reconstruction performance with lower errors in mapping and comparable performance in and proton density mappings. When compared to other model-based approaches including GraSP and MOBA, AMP-PE exhibited greater robustness and outperformed GraSP in reconstruction error. AMP-PE offers faster speed than MOBA. AMP-PE performed better than MOBA at higher sampling rates and worse than MOBA at a lower sampling rate. Notably, AMP-PE eliminates the need for hyperparameter tuning, which is a requisite for all the other approaches. AMP-PE offers the benefits of model-based recovery with the additional key advantage of automatic hyperparameter estimation. It works adeptly in situations where ground-truth is difficult to obtain and in clinical environments where it is desirable to automatically adapt hyperparameters to individual protocol, scanner and patient.

Evaluation of the impact of ultra-trail running on knee cartilage using magnetic resonance imaging t2 mapping.

Ultra-marathon trails involve a combination of specific physiological and mechanical constraints and raise new questions regarding the osteoarticular impact on the knees and the long-term risk of osteoarthritis. Magnetic resonance imaging (MRI) T2 relaxation time measurement has shown the ability to determine cartilage response to loading. Higher T2 measurements correspond with cartilage damage. The aim of this study was to quantify the changes in MRI T2 relaxation times of knee articular cartilage after an ultra-trail run and determine knee's consequences of regular practice. Twenty participants in a 55-km race involving total elevation changes of 2600m had 1.5-T knee MRI prior to the race (V0), immediately after (V1) and one month after the race (V2) for T2 relaxation times measurement and morphological sequences (T1, T2 & T2 Fast-Spin Echo (FSE)). T2 measurements were significantly increased in V1 from V0 and remained so one month after the race (V2), despite a significant reduction from V1. Morphological sequences revealed that 65% of the participant had cartilage damage and 65% meniscal damage, 100% of which affected the posterior horn of the medial meniscus. Only one subject (5%) presented no anomaly whatsoever. Damage appeared to be stable between the assessments. Ultra-trail running leads to modifications in the knee cartilage ultrastructure, which persists for at least one month after the event. Furthermore, regular ultra-trail runners present a high number of low-grade cartilage and meniscus lesions.

Glutamate chemical exchange saturation transfer (GluCEST) MRI to evaluate the relationship between demyelination and glutamate content in depressed mice

Glutamatergic alteration is one of the potential mechanisms of depression. However, there is no consensus on whether glutamate metabolism changes affect the myelin structure of depression in mouse models. Glutamate chemical exchange saturation transfer (GluCEST) is a novel and powerful molecular imaging technique that can visualize glutamate distribution. In this study, we used the GluCEST imaging technique to look at glutamate levels in mice under chronic unpredictable mild stress (CUMS) and how they relate to demyelination. The CUMS mice were exposed to different stress factors for 6 weeks. Evaluated of depression in CUMS mice by behavioral tests. MRI scans were then performed, including T2-mapping, GluCEST, and diffusion tensor imaging (DTI) sequences. Brain tissues were collected for Luxol Fast Blue staining and immunofluorescence staining to analyze the changes in the myelin sheath. Artificially sketched regions of interest (ROI) (corpus callosum, hippocampus, and thalamus) were used to calculate the GluCEST value, fractional anisotropy (FA), and T2 value. Compared with the control group, the GluCEST value in the ROIs of CUMS mice significantly decreased. Similarly, the FA value in ROIs was lower in the CUMS group than in the CTRL group, but the T2 value did not differ significantly between the two groups. The histological results showed that ROIs in the CUMS group had demyelination compared with the CTRL group, indicating that DTI was more sensitive than T2 mapping in detecting myelin abnormalities. Furthermore, the GluCEST value in the ROIs correlates positively with the FA value. These findings suggest that altered glutamate metabolism may be one of the important factors leading to demyelination in depression, and GluCEST is expected to serve as an imaging biological marker for the diagnosis of demyelination in depression.

Role of advanced CMR features in identifying a positive genotype of hypertrophic cardiomyopathy

BackgroundHypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disease that affects approximately one in 500 people. Cardiac magnetic resonance (CMR) imaging has emerged as a powerful tool for the non-invasive assessment of HCM. CMR can accurately quantify the extent and distribution of hypertrophy, assess the presence and severity of myocardial fibrosis, and detect associated abnormalities. We will study basic and advanced features of CMR in 2 groups of HCM patients with negative and positive genotype, respectively. Materials and methodsThe study population consisted in consecutive HCM patients referred to Centro Cardiologico Monzino who performed both CMR and genetic testing. Clinical CMR images were acquired at 1.5 T Discovery MR450 scanner (GE Healthcare, Milwaukee, Wisconsin)) using standardized protocols T1 mapping, T2 mapping and late gadolinium enhancement (LGE). Population was divided in 2 groups: group 1 with HCM patients with a negative genotype and group 2 with a positive genotype. ResultsThe analytic population consisted of 110 patients: 75 in group 1 and 35 patients in group 2.At CMR evaluation, patients with a positive genotype had higher LV mass (136 vs. 116 g, p = 0.02), LV thickness (17.5 vs. 16.9 mm), right ventricle ejection fraction (63 % vs. 58 %, p = 0.002).Regarding the LGE patients with positive genotype have a higher absolute (33.8 vs 16.7 g, p = 0.0003) and relative LGE mass (31.6 % vs 14.6 %, p = 0.0007). On a segmental analysis all the septum (segments 2, 8, 9, and 14) had a significantly increased native T1 compared to others segments. ECV in the mid antero and infero-septum (segments 8 and 9) have lower values in positive genotype HCM. Interestingly the mean T2 was lower in positive genotype HCM as compared to negative genotype HCM (50,1 ms vs 52,4). ConclusionsOur paper identifies the mid septum (segments 8 and 9) as a key to diagnose a positive genotype HCM.

Changes in inflammatory edema and fat fraction of thigh muscles following a half-marathon in recreational marathon runners.

It is known that microtrauma exists in the thigh muscles after long-distance running such as the half-marathon. Moreover, training characteristics of long-distance runners may influence the specificity of the distribution of muscle fiber types in the thigh and affect muscle responses to lipid metabolism. However, the specific changes in microtrauma and intramuscular lipid in thigh muscles after a half-marathon are unknown. A cohort of 20 healthy recreational marathon runners was recruited to complete a half-marathon. MRI T2 mapping and 6-echo q-Dixon sequences were employed at baseline (P1), 2-3h after running (P2), and 1day after running (P3). Inflammatory markers (the T2 values) and intramuscular fat fraction (the proton density fat fraction, PDFF) were measured in thigh muscles to detect microtrauma and intramuscular lipid changes, respectively. One-way analysis of variance showed significant time effects for T2 values and PDFF. Post hoc analysis of the 14 datasets collected at three time points revealed significantly higher T2 values in all thigh muscles after running (all p<0.05). Significant differences in T2 values persisted for all thigh muscles at P3 compared to P1 (all p<0.05). The PDFF of the vastus lateralis and vastus medialis was significantly decreased at P2 compared to P1 (p<0.05). No significant differences in PDFF were observed for the thigh muscles at P3 compared to P1. The manifestations of inflammation edema and intramuscular lipid investigated through MRI may offer valuable insights for recreational marathon runners regarding the lower limb movement characteristics during half-marathon running.

Feasibility and Reproducibility of T2 Mapping Compared with Diffusion-Weighted Imaging in Solid Renal Masses.

Accurate prediction of renal mass subtypes, along with the WHO/ISUP grade and pathological T (pT) stage of clear cell renal cell carcinoma (ccRCC), is crucial for optimal decision making. Our study aimed to investigate the feasibility and reproducibility of motion-robust radial T2 mapping in differentiating lipid-poor angiomyolipoma (MFAML) from RCC and characterizing the WHO/ISUP grade and pT stage of ccRCC. Finally, 92 patients undergoing renal radial T2 mapping and ZOOMit DWI were recruited. The T2 values and apparent diffusion coefficient (ADC) were analyzed. Correlation coefficients were calculated between ADC and T2 values. Notably, ccRCC exhibited higher T2 and ADC values than MFAML (p < 0.05). T2 values were lower in the higher WHO/ISUP grade and pT stage of ccRCC (all p < 0.05). ADC showed no significant difference for pT stage (p = 0.056). T2 values revealed a higher area under the curve (AUC) in evaluating the WHO/ISUP grade compared to ADC (0.936 vs. 0.817, p = 0.027). T2 values moderately positively correlated with ADC (r = 0.675, p < 0.001). In conclusion, quantitative motion-robust radial T2 mapping is feasible for characterizing solid renal masses and could provide additional value for multiparametric imaging in predicting WHO/ISUP grade and pT stage of ccRCC.

Age and sex-related differences in T1 and T2 mapping. 1.5 magnetic resonance referent values

Introduction: Parametric mapping is a non-invasive method to quantify tissue changes in the myocardium by measuring T1, T2 and T2* relaxation times and extracellular volume, requiring a pre-established range of normal values. Purpose: To establish reference values for native T1 and T2 myocardial relaxation times in healthy subjects on 1.5 T magnetic resonance imaging and to assess changes in their values according to left ventricular segments, age, sex, heart rate, and myocardial thickness. Material and Methods: A prospective 1.5 T magnetic resonance imaging study was performed with the voluntary participation of 50 healthy individuals in different age groups. Image analysis was performed by a radiologist with 5 years of experience in the field of CMRT and further coordinated with a radiologist with more than 20 years of expe-rience in the field. Siemens ARGUS integrated software was used to calculate the volumes and function of both cameras. Global and segmental T1 and T2 values were measured in the shortaxis midlevel section by manually delineating the region of interest. Myocardial thickness of the mid septum was measured for each patient. Results: The distribution of volunteers was 25 men and 25 women. Significantly higher global T1 values were observed in women (1027.7 &amp;plusmn; 25.4 ms) compared to men (992.9 &amp;plusmn; 24.4 ms), at p &lt; 0.001. The same correlation was observed in individual segments, with a significant difference between genders. Examination of the correlation between T1 and other parameters demonstrated a negative linear relationship only with myocardial thickness. Global T2 in women (48.6 &amp;plusmn; 2.49 ms) was also significantly higher than in men (44.6 &amp;plusmn; 2.06 ms), with an observed difference of 3.95, p &lt; 0.001. Global T2 showed a very strong negative correlation with myocardial thickness (r = -0.769; p &lt; 0.001). There was no sig-nificant correlation between T2 times and heart rate and age of patients. Conclusion: A statistically significant difference in native T1 and T2 values by sex was demonstrated. The use of sex-specific reference values to distinguish healthy from pathologically affected myocardium is recommended.