[Evaluation of cerebral vasospasm resulting from subarachnoid hemorrhage with 1H-magnetic resonance spectroscopy].

ABSTRACT

OBJECTIVE: To assess the value of (1)H-magnetic resonance spectroscopy ((1)H-MRS) in evaluating cerebral vasospasm resulting from subarachnoid hemorrhage (SAH). METHODS: Six dogs were subjected to autologous non-heparinized blood injection via cisternal puncture twice at one-day interval to establish models of SAH, and another 6 received injections with normal saline in an identical manner. (1)H-MRS scan was performed on the 3rd, 7th and 14th days after the injections to measure the changes of N-acetylaspartate (NAA), creatine (Cr) and choline (Cho). After the (1)H-MRS scan, all the dogs underwent brain digital subtraction angiography (DSA) for determining the basilar artery diameter. RESULTS: DSA results on day 3 presented development of obvious vasospasm of the basilar artery, which was most evident on day 7 and recovered obviously on day 14. (1)H-MRS results demonstrated obvious changes of NAA, Cho and Cr on days 3 and 7 in SAH model group, and NAA declined to the lowest level on day 3 followed by gradual ascending till reaching the normal level on day 14. Cho decreased slightly on day 3, then increased and reached the peak level on day 7 and then decreased. Cr rose steadily from day 3 to 14, but since day 7, the rise slowed down obviously and Cr maintain a level not significantly different from that on day 14 (P>0.05). The functional results of (1)H-MRS were consistent with the DSA results. CONCLUSION: (1)H-MRS can be used to monitor the development of cerebral vasospasm resulting from SAH as a good evaluation method for functional imaging.