MR spectroscopy may have a role in identifying and following the course of treatment in patients with anorexia nervosa, results of a small German study suggest.
A comparison of anorexia nervosa patients and controls showed significant differences in several parameters of brain metabolism before and after visual stimulation. Additional investigation of four patients showed that 31P-MR spectroscopy could detect changes in brain metabolism associated with treatment, Reinhard Rzanny, a clinical psychologist, reported at an RSNA scientific session.
During the first phase of investigation, researchers at the University of Jena used 31P-MR spectroscopy to evaluate phosphorus metabolism in seven patients with diagnosed anorexia nervosa and in seven controls. Measurements were made before, during, and after cognitive activation related to viewing word-color associations. Scanning focused on the frontal cortex, and every scan lasted 13 minutes, Rzanny said.
Prior to visual stimulation, spectroscopic measurements showed lower values for anorganic phosphate and phosphodiesters in patients as compared to controls. Phosphocreatine and beta-ATP values were higher in the patients. During cognitive activation, phosphocreatine values increased in controls but not individuals with anorexia nervosa. Moreover, increased intensity in the phosphomonoester region occurred in patients but not controls.
In a second phase of investigation, the researchers compared brain metabolism values in treated and untreated anorexia patients and in controls. They found that cognitive activation was associated with decreased signal intensity for anorganic phosphate in controls and in patients who had achieved normal weight after psychological intervention. No change in anorganic phosphate values was observed in untreated anorexia nervosa patients.
"These results show that MR spectroscopy detects changes in brain metabolism during cognitive activation," Rzanny said. "The findings suggest that spectroscopy evaluation may be useful in identifying anorexia nervosa patients and in following the course of their therapy."
