Dynamic and static Tc-99m-ECD SPECT imaging of subacute cerebral infarction: Comparison with Xe-133 SPECT

Citation
K. Ogasawara et al., Dynamic and static Tc-99m-ECD SPECT imaging of subacute cerebral infarction: Comparison with Xe-133 SPECT, J NUCL MED, 42(4), 2001, pp. 543-547
Citations number
14
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
Journal title
JOURNAL OF NUCLEAR MEDICINE
ISSN journal
0161-5505 → ACNP
Volume
42
Issue
4
Year of publication
2001
Pages
543 - 547
Database
ISI
SICI code
0161-5505(200104)42:4<543:DASTSI>2.0.ZU;2-T
Abstract
Tc-99m-ethylcysteinate dimer (Tc-99m-ECD) SPECT imaging reportedly fails to show reflow hyperemia in patients with subacute stroke. This study attempt s to determine the clinical usefulness of dynamic Tc-99m-ECD SPECT in evalu ating regional blood flow in subacute cerebral infarction and the kinetic b ehavior of Tc-99m-ECD in infarct areas. Methods: Xe-133 and consecutive dyn amic and static Tc-99m-ECD SPECT studies were performed on 24 patients with cortical infarction in the middle cerebral artery territory 13-15 d after the onset of a stroke. Image contrast between infarct and contralateral con trol areas on Tc-99m-ECD tomograms (ECD uptake ratio) was compared with tha t on cerebral blood flow (CBF) images obtained using Xe-133 inhalation (CBF ratio). Results: In all cases, ECD uptake ratios from static images were l ower than CBF ratios. This tendency was obvious when CBF in the infarct are a increased above the normal control value, and no significant correlation was found between ECD uptake ratios from static images and CBF ratios. Only in the infarct areas with CBF below the normal control value, however, was a significant correlation between the two maintained (r = 0.795; P = 0.001 1). A very strong correlation was found between CBF ratios and ECD uptake r atios on both the first dynamic scan (36 s after injection) (r = 0.991; P < 0.0001) and the second dynamic scan (72 s after injection) (r = 0.945; P < 0.0001). The correlation coefficient decreased in a time-dependent manner, with no significant correlation observed after the fourth dynamic scan (14 4 a after injection). On the other hand, significant correlations were obse rved on all dynamic scans only in the infarct areas with CBF below the cont rol value. Conclusion: Super-early images of dynamic Tc-99m-ECD SPECT provi de a close imaging contrast with CBF and reveal reflow hyperemia in areas w ith irreversible changes produced by subacute stroke, which static Tc-99m-E CD SPECT images fail to show. Decreased retention of the tracer in the infa rct areas with hyperperfusion causes an underestimation of CBF on static Tc -99m-ECD SPECT images. Given these results, we believe that dynamic Tc-99m- ECD SPECT is an effective clinical tool to evaluate regional blood flow in subacute cerebral infarction.