TC-99M-HMPAO SPECT OF THE BRAIN IN MILD-TO-MODERATE TRAUMATIC BRAIN INJURY PATIENTS - COMPARED WITH CT - A PROSPECTIVE-STUDY

Single photon emission computed tomography (SPECT) with Technetium-99m hexamethyl propylenamine oxime (Tc-99m-HMPAO) was used in 20 patients with mild to moderate traumatic brain injury (TBI) to evaluate the ef fects of brain trauma on regional cerebral blood flow (rCBF). SPECT sc an was compared with CT scan in 16 patients. SPECT showed intraparench ymal differences in rCBF more often than lesions diagnosed with CT sca ns (87.5% vs. 37.5%). In five of six patients with lesions in both mod alities, the area of involvement was relatively larger on SPECT scans than on CT scans. Contrecoup changes were seen in five patients on SPE CT alone, two patients with CT alone and one patient had contrecoup le sions on CT and SPECT. Of the eight patients (50%) with skull fracture s, seven (43.7%) had rCBF findings on SPECT scan and five (31.3%) demo nstrated decrease in rCBF in brain underlying the fracture. All these patients with fractures had normal brain on CT scans. Conversely, extr a-axial lesions and fractures evident on CT did not visualize on SPECT , but SPECT demonstrated associated changes in rCBF. Although there is still lack of clinical and pathological correlation, SPECT appears to be a promising method for a more sensitive evaluation of axial lesion s in patients with mild to moderate TBI.