Combining proton and phosphorus magnetic resonance spectroscopy offers a unique opportunity to study the oxidative and glycolytic components of metabolism in working muscle. This paper presents a 7 T proton calf coil design that combines dipole and loop elements to achieve the high performance necessary for detecting metabolites with low abundance and restricted visibility, specifically lactate, while including the option of adding a phosphorus array. We investigated the transmit, receive, and parallel imaging performance of three transceiver dipoles with six pair-wise overlap-decoupled standard or twisted pair receive-only coils. With a higher SNR and more efficient transmission decoupling, standard loops outperformed twisted pair coils. The dipoles with standard loops provided a four-fold-higher image SNR than a multinuclear reference coil comprising two proton channels and 32% more than a commercially available 28-channel proton knee coil. The setup enabled up to three-fold acceleration in the right-left direction, with acceptable g-factors and no visible aliasing artefacts. Spectroscopic phantom measurements revealed a higher spectral SNR for lactate with the developed setup than with either reference coil and fewer restrictions in voxel placement due to improved transmit homogeneity. This paper presents a new use case for dipoles and highlights their advantages for the integration in multinuclear calf coils.

• Klíčová slova
• magnetic resonance imaging, magnetic resonance spectroscopy, muscle metabolism, radiofrequency coil, ultra-high field,
• MeSH
• fantomy radiodiagnostické * MeSH
• kosterní svaly * diagnostické zobrazování   chemie   MeSH
• kyselina mléčná chemie   metabolismus   MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• magnetická rezonanční tomografie * metody   MeSH
• poměr signál - šum MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyselina mléčná MeSH

OBJECTIVES: Diabetic foot syndrome (DFS) is a serious late diabetic complication characterised by limited joint mobility and other biomechanical and muscle abnormalities. AIM: To evaluate the effect of an interventional exercise programme on anthropometric parameters, muscle strength, mobility and fitness in patients with diabetic foot in remission. DATA SOURCES AND STUDY SELECTION: Thirty-eight patients with type 2 diabetes and DFS without active lesions (mean age 65 ± 6.9 years, BMI 32 ± 4.7 kg.m-2, waist-hip ratio (WHR)1.02 ± 0.06) were enrolled in our randomised controlled trial. All subjects were randomised into two groups: an intervention group (I; n=19) and a control group (C; n=19). The 12-week exercise intervention focused on ankle and small-joint mobility in the foot, strengthening and stretching of the lower extremity muscles, and improvements in fitness. Changes (Δ=final minus initial results) in physical activity were assessed using the International Physical Activity Questionnaire (IPAQ), with joint mobility detected by goniometry, muscle strength by dynamometry, and fitness using the Senior Fitness Test (SFT). DATA EXTRACTION: Due to reulceration, 15.8% of patients from group I (3/19) and 15.8% of patients from group C were excluded. Based on the IPAQ, group I was more active when it came to heavy (p=0.03) and moderate physical activity (p=0.06) after intervention compared to group C. Group I improved significantly in larger-joint flexibility (p=0.012) compared to controls. In group I, dynamometric parameters increased significantly in both lower limbs (left leg; p=0.013, right leg; p=0.043) compared to group C. We observed a positive trend in the improvement of fitness in group I compared to group C. We also confirmed positive correlations between heavy physical activity and selected parameters of flexibility (r=0.47; p=0.007), SFT (r=0.453; p=0.011) and dynamometry (r=0.58; p<0.0025). Anthropometric parameters, such as BMI and WHR, were not significantly influenced by the intervention programme. CONCLUSION: Our 12-week interventional exercise programme proved relatively safe, resulting in improved body flexibility and increased muscle strength in DF patients in remission.

• Klíčová slova
• diabetes mellitus, diabetic foot, education, exercise, physical activity,
• MeSH
• cvičení fyziologie   MeSH
• diabetes mellitus 2. typu * komplikace   terapie   MeSH
• diabetická noha * terapie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• svalová síla fyziologie   MeSH
• terapie cvičením MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH

Most in vivo 31P MR studies are realized on 3T MR systems that provide sufficient signal intensity for prominent phosphorus metabolites. The identification of these metabolites in the in vivo spectra is performed by comparing their chemical shifts with the chemical shifts measured in vitro on high-field NMR spectrometers. To approach in vivo conditions at 3T, a set of phantoms with defined metabolite solutions were measured in a 3T whole-body MR system at 7.0 and 7.5 pH, at 37 °C. A free induction decay (FID) sequence with and without 1H decoupling was used. Chemical shifts were obtained of phosphoenolpyruvate (PEP), phosphatidylcholine (PtdC), phosphocholine (PC), phosphoethanolamine (PE), glycerophosphocholine (GPC), glycerophosphoetanolamine (GPE), uridine diphosphoglucose (UDPG), glucose-6-phosphate (G6P), glucose-1-phosphate (G1P), 2,3-diphosphoglycerate (2,3-DPG), nicotinamide adenine dinucleotide (NADH and NAD+), phosphocreatine (PCr), adenosine triphosphate (ATP), adenosine diphosphate (ADP), and inorganic phosphate (Pi). The measured chemical shifts were used to construct a basis set of 31P MR spectra for the evaluation of 31P in vivo spectra of muscle and the liver using LCModel software (linear combination model). Prior knowledge was successfully employed in the analysis of previously acquired in vivo data.

• Klíčová slova
• 31P MRS, LCModel, in vivo MR spectroscopy, liver, muscle,
• MeSH
• adenosindifosfát metabolismus   MeSH
• adenosintrifosfát metabolismus   MeSH
• fosfatidylcholiny metabolismus   MeSH
• fosfatidylethanolaminy metabolismus   MeSH
• fosfáty metabolismus   MeSH
• fosfor metabolismus   MeSH
• játra metabolismus   MeSH
• kosterní svaly metabolismus   MeSH
• lidé MeSH
• nukleární magnetická rezonance biomolekulární * MeSH
• pilotní projekty MeSH
• software * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• Názvy látek
• adenosindifosfát MeSH
• adenosintrifosfát MeSH
• fosfatidylcholiny MeSH
• fosfatidylethanolaminy MeSH
• fosfáty MeSH
• fosfor MeSH

Skeletal muscle phosphorus-31 31 P MRS is the oldest MRS methodology to be applied to in vivo metabolic research. The technical requirements of 31 P MRS in skeletal muscle depend on the research question, and to assess those questions requires understanding both the relevant muscle physiology, and how 31 P MRS methods can probe it. Here we consider basic signal-acquisition parameters related to radio frequency excitation, TR, TE, spectral resolution, shim and localisation. We make specific recommendations for studies of resting and exercising muscle, including magnetisation transfer, and for data processing. We summarise the metabolic information that can be quantitatively assessed with 31 P MRS, either measured directly or derived by calculations that depend on particular metabolic models, and we give advice on potential problems of interpretation. We give expected values and tolerable ranges for some measured quantities, and minimum requirements for reporting acquisition parameters and experimental results in publications. Reliable examination depends on a reproducible setup, standardised preconditioning of the subject, and careful control of potential difficulties, and we summarise some important considerations and potential confounders. Our recommendations include the quantification and standardisation of contraction intensity, and how best to account for heterogeneous muscle recruitment. We highlight some pitfalls in the assessment of mitochondrial function by analysis of phosphocreatine (PCr) recovery kinetics. Finally, we outline how complementary techniques (near-infrared spectroscopy, arterial spin labelling, BOLD and various other MRI and 1 H MRS measurements) can help in the physiological/metabolic interpretation of 31 P MRS studies by providing information about blood flow and oxygen delivery/utilisation. Our recommendations will assist in achieving the fullest possible reliable picture of muscle physiology and pathophysiology.

• Klíčová slova
• 31P, MRI, exercise, metabolism, muscle, nuclear magnetic resonance spectroscopy, phosphorus MRS,
• Publikační typ
• časopisecké články MeSH

Magnetic Resonance (MR) compatible ergometers are specialized ergometers used inside the MR scanners for the characterization of tissue metabolism changes during physical stress. They are most commonly used for dynamic phosphorous magnetic resonance spectroscopy (31P MRS), but can also be used for lactate production measurements, perfusion studies using arterial spin labelling or muscle oxygenation measurements by blood oxygen dependent contrast sequences. We will primarily discuss the importance of ergometers in the context of dynamic 31P MRS. Dynamic 31P MRS can monitor muscle fatigue and energy reserve during muscle contractions as well as the dynamics of recuperation of skeletal muscle tissue during the following recovery through signal changes of phosphocreatine (PCr), inorganic phosphate and adenosine triphosphate (ATP). Based on the measured data it is possible to calculate intracellular pH, metabolic flux of ATP through creatine-kinase reaction, anaerobic glycolysis and oxidative phosphorylation and other metabolic parameters as mitochondrial capacity. This review primarily focuses on describing various technical designs of MR compatible ergometers for dynamic 31P MRS that must be constructed with respect to the presence of magnetic field. It is also expected that the construction of ergometers will be easy for the handling and well accepted by examined subjects.

• Klíčová slova
• Dynamic 31P magnetic resonance spectroscopy, Exercise, MR ergometer, Muscle examination,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH