Diffusion tensor imaging combined with T2 mapping to quantify changes in the skeletal muscle associated with training and endurance exercise in competitive triathletes.

OBJECTIVES: Diffusion tensor magnetic resonance imaging (DTI) and T2 mapping enable the detection of exercise-induced changes in the skeletal muscle microenvironment. This study prospectively quantified DTI metrics and T2 relaxation times of thigh muscles in competitive triathletes at rest and following a triathlon race in comparison with sedentary controls. METHODS: Twenty-two triathletes (males N = 16, females N = 6) and twenty-three controls (males N = 16, females N = 7) underwent magnetic resonance imaging (MRI) on a 3 T system at baseline (time point 1; 72 h at rest). Twelve triathletes (males N = 8, females N = 4) underwent a second scan (time point 2; 3 h of completing a triathlon race). The tensor eigenvalues (λ1, λ2, λ3), mean diffusivity (MD), fractional anisotropy (FA), and T2 times were compared between controls and triathletes at time point 1 and triathletes at time points 1 and 2 using independent and paired t tests. RESULTS: In comparison with the controls at time point 1, the T2 times of rectus femoris (RF, p < 0.02), adductor magnus (AM, p = 0.02), biceps femoris (BF, p < 0.001), semitendinosus (ST, p = 0.005), and semimembranosus (SM, p = 0.003) muscles were significantly increased in triathletes. At time point 2 in triathletes, the average tensor metrics (MD, λ3/ λ1) of BF, ST, and SM muscles increased (p < 0.05) and FA values in ST and SM muscles decreased (p < 0.03). T2 times were not significantly changed between both time points in triathletes. CONCLUSION: Our results indicate that this multiparametric MRI protocol allows detection and quantification of changes in the skeletal muscle microenvironment caused by endurance training and acute strenuous exercise. KEY POINTS: • Endurance training results in changes to the skeletal microstructure, which can be quantified using MRI-based diffusion tensor imaging. • The combined application of MRI diffusion tensor imaging and T2 mapping allows the differentiation of microstructural changes caused by active exercise or endurance training. • Environmental adaptations of the skeletal muscle caused by physical training are influenced by gender.

[Cardiac arrest in a fitness trainer with apical hypertrophic cardiomyopathy associated with cor triatriatum sinister]. / Plötzlicher Herztod einer Fitnesstrainerin mit hypertropher Kardiomyopathie vom apikalen Typ assoziiert mit Cor triatriatum sinister.

We report on a 49-year-old fitness trainer, who was admitted to our hospital after cardiac arrest due to ventricular fibrillation. Return of spontaneous circulation was achieved after immediate cardiopulmonary resuscitation. Coronary angiography could exclude coronary artery disease. Echocardiography demonstrated the presence of apical hypertrophic cardiomyopathy, associated with cor triatriatum sinister. Cardiac magnetic resonance imaging additionally showed marked myocardial fibrosis. The patient underwent placement of an implantable cardioverter-defibrillator and was subsequently discharged for rehabilitation in good condition.