PHOSPHORUS AND PROTON SPECTROSCOPY IN RELATION TO NEAR INCARCERATION AND INCARCERATION OF THE HUMAN BRAIN

We report 3 cases of P-31 and H-1 MR spectroscopy (MRS) performed at d ifferent stages on patients with clinical signs of near or fulminant i ncarceration of the brain. The measurements were made on a whole body, 1.5 T scanner. H-1-MRS was obtained with the STEAM sequence and P-31- spectra were obtained using the chemical shift imaging technique. Medi cal treatment including controlled ventilation and sedation of the pat ients was carried out during the examination. The first patient was ev aluated on days 6 and 10 after evacuation of an acute subdural haemato ma. An intracranial pressure of 35 mm Hg was registered during the fir st examination. The 2nd patient had suffered a spontaneous intracerebr al haemorrhage and showed clinical signs of imminent incarceration dur ing the examination. The 3rd patient showed clinical signs of incarcer ation just prior to the examination. In the Ist patient H-1-MRS showed a 3-fold increase in the concentration of choline-containing compound s and a small decrease in N-acetyl aspartate from the Ist to the 2nd e xamination, which we interpret as a loss of neurones. In case 2 only s mall changes in metabolism could be detected, indicating that, despite signs of imminent clinical incarceration, the energy supply to the br ain was substantial. H-1-MRS of the 3rd patient showed massive lactate concentration, and P-31-MRS revealed the total absence of high-energy phosphorous compounds leaving only one single peak of inorganic phosp hate, indicating irreversible brain death.