“…5,196 Spectroscopy In addition to providing anatomical images of the body, MR can also be utilized for in vivo spectroscopic chem-ical analyses. 22,76,199,200 Abnormalities have also been identified in Duchenne type muscular dystrophy,200 myopathies due to hypothyroidism,199 and viral infec¬ tion.200 An in vivo study of an 8-monthold infant with an idiopathic cardiomyopathy identified abnormal ratios of phosphocreatine to inorganic phos¬ phorus and showed improvement fol¬ lowing therapy with a carbohydrate load.201 In vivo studies of two patients with neuroblastoma identified a high concentration of a phosphomonoester in the primary tumor and liver metas¬ tasis. Up to the present time, most of the studies have involved phosphorus and phosphoruscontaining compounds.22 It is possible to measure, in vivo, the concentration of a wide range of phosphorus-contain¬ ing compounds and also to calculate the intracellular pH.…”