Correlation of magnetic resonance imaging findings with hexamethylpropyleneamine oxime brain single photon emission computed tomography in ischemic stroke patients in the subacute stage

Abstract

To evaluate the correlation between magnetic resonance imaging (MRI) findings and 99mTc-hexamethylpropyleneamine oxime (HMPAO) brain single photon emission computed tomography (SPECT) during the subacute stage in ischemic stroke patients. The T1 and T2-weighted images and brain SPECT findings of 84 patients (mean age 60.69 +/- 12.47 years) with subacute cerebral ischemia during the period 1998-2004 were reviewed. All HMPAO SPECT and MRI studies were performed between 3 and 7 days (mean time delay 4.76 +/- 1.29 days) after the onset of stroke symptoms. An ischemic lesion was seen both in T1 and T2-weighted images with perfusion defects above 60% (severe defect) according to count/pixel data of the lesion in HMPAO SPECT studies in 30 (90.9%) of 33 patients. Otherwise, the ischemic lesion was seen only on T2-weighted images with perfusion defects between 30% and 60% (moderate defect) in HMPAO SPECT studies in 25 (89.3%) of 28 patients. In 20 (87%) of 23 patients who had perfusion defects below 30% (mild defect) on HMPAO SPECT, only non-specific findings such as cerebral atrophy and/or periventricular ischemic-gliotic lesions could be seen in MRI. The difference between these ratios was statistically significant (P < 0.01). Brain 99mTc-HMPAO SPECT findings indicate good correlation with MRI findings. When the ischemic lesions could be seen in both T1 and T2-weighted images, the patients frequently had severe perfusion defects. When only seen in T2-weighted images, the perfusion defect was moderate. When only non-specific findings were revealed by MRI, only mild perfusion defects were found by SPECT.