BACKGROUND: Skeletal muscle alterations are associated with higher mortality and morbidity in patients with liver cirrhosis. Assessing these changes seems to be a promising method for identifying patients at a high risk of poor outcomes following liver transplantation (LT). This is particularly important given the current global shortage of organ donors. However, evidence of the impact of these alterations on the prognosis of patients undergoing LT is inconclusive. The aim of our prospective study was to evaluate the impact of skeletal muscle changes, reflected in sarcopenia, myosteatosis and metabolic changes in the calf muscles, on perioperative outcomes and long-term survival after LT. We also sought to determine the posttransplant evolution of the resting muscle metabolism. METHODS: We examined 134 adult LT candidates. Of these, 105 underwent LT. Sarcopenia and myosteatosis were diagnosed by measuring the skeletal muscle index and mean psoas muscle radiation attenuation, respectively, which were obtained from computed tomography (CT) scans taken during pretransplant assessment. Additionally, patients underwent 31P MR spectroscopy (MRS) of the calf muscles at rest before LT and 6, 12 and 24 months thereafter. The median follow-up was 6 years. RESULTS: Patients with abnormal 31P MRS results and CT-diagnosed myosteatosis prior to LT had significantly worse long-term survival after LT (hazard ratio (HR), 3.36; 95% confidence interval (CI), 1.48-7.60; p = 0.0021 and HR, 2.58; 95% CI, 1.06-6.29; p = 0.03, respectively). Multivariable analysis showed that abnormal 31P MR spectra (HR, 3.40; 95% CI, 1.50-7.71; p = 0.003) were a better predictor of worse long-term survival after LT than myosteatosis (HR, 2.78; 95% CI, 1.14-6.78; p = 0.025). Patients with abnormal 31P MR spectra had higher blood loss during LT (p = 0.038), required a higher number of red blood cell transfusions (p = 0.006) and stayed longer in ICU (p = 0.041) and hospital (p = 0.007). Myosteatosis was associated with more revision surgeries following LT (p = 0.038) and a higher number of received red blood cell transfusion units (p = 0.002). Sarcopenia had no significant effect on posttransplant patient survival. An improvement in the resting metabolism of the calf muscles was observed at 12 and 24 months after LT. CONCLUSIONS: Abnormal 31P MRS results of calf muscles were superior to CT-based diagnosis of myosteatosis and sarcopenia in predicting perioperative complications and long-term survival after LT. Resting muscle metabolism normalized 1 year after LT in most recipients.

• Keywords
• 31P MR spectroscopy, liver transplantation, myosteatosis, sarcopenia, skeletal muscle,
• MeSH
• Adult MeSH
• Muscle, Skeletal * diagnostic imaging   metabolism   MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy * methods   MeSH
• Tomography, X-Ray Computed * methods   MeSH
• Prognosis MeSH
• Prospective Studies MeSH
• Sarcopenia etiology   metabolism   MeSH
• Aged MeSH
• Liver Transplantation * MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

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.

• Keywords
• magnetic resonance imaging, magnetic resonance spectroscopy, muscle metabolism, radiofrequency coil, ultra-high field,
• MeSH
• Phantoms, Imaging * MeSH
• Muscle, Skeletal * diagnostic imaging   chemistry   MeSH
• Lactic Acid chemistry   metabolism   MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy methods   MeSH
• Magnetic Resonance Imaging * methods   MeSH
• Signal-To-Noise Ratio MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Lactic Acid MeSH

This current opinion article critically evaluates the efficacy of autologous cell therapy (ACT) for chronic limb-threatening ischemia (CLTI), especially in people with diabetes who are not candidates for standard revascularization. This treatment approach has been used in 'no-option' CLTI in the last two decades and more than 1700 patients have received ACT worldwide. Here we analyze the level of published evidence of ACT as well as our experience with this treatment method. Many studies have shown that ACT is safe and an effective method for patients with the most severe lower limb ischemia. However, some trials did not show any benefit of ACT, and there is some heterogeneity in the types of injected cells, route of administration and assessed endpoints. Nevertheless, we believe that ACT plays an important role in a comprehensive treatment of patients with diabetic foot and severe ischemia.

• MeSH
• Amputation, Surgical MeSH
• Cell- and Tissue-Based Therapy MeSH
• Diabetes Mellitus * MeSH
• Diabetic Foot * therapy   MeSH
• Ischemia etiology   therapy   MeSH
• Humans MeSH
• Retrospective Studies MeSH
• Risk Factors MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't 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.

• Keywords
• 31P MRS, LCModel, in vivo MR spectroscopy, liver, muscle,
• MeSH
• Adenosine Diphosphate metabolism   MeSH
• Adenosine Triphosphate metabolism   MeSH
• Phosphatidylcholines metabolism   MeSH
• Phosphatidylethanolamines metabolism   MeSH
• Phosphates metabolism   MeSH
• Phosphorus metabolism   MeSH
• Liver metabolism   MeSH
• Muscle, Skeletal metabolism   MeSH
• Humans MeSH
• Nuclear Magnetic Resonance, Biomolecular * MeSH
• Pilot Projects MeSH
• Software * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Names of Substances
• Adenosine Diphosphate MeSH
• Adenosine Triphosphate MeSH
• Phosphatidylcholines MeSH
• Phosphatidylethanolamines MeSH
• Phosphates MeSH
• Phosphorus MeSH