The application value of dual-layer detector spectral CT angiography in evaluation of brain perfusion in patients with acute ischemic stroke / 中华放射学杂志

ABSTRACT

Objective:To explore the clinical application value of the dual-layer detector spectral CTA in evaluation of brain perfusion impairment in patients with acute ischemic stroke.Methods:Clinical and imaging data of 35 patients with acute ischemic stroke in Weihai Central Hospital from March 2020 to October 2020 were reviewed retrospectively. All patients underwent head and neck spectral CTA examination and dynamic cerebral perfusion CT examination with dual-layer detector spectral CT. The iodine density map and effective atomic number map were reconstructed using CTA data, and the iodine density and effective atomic number, as well as the cerebral blood volume (CBV) and cerebral blood flow (CBF) values of the hypoperfusion area and the contralateral side were measured and compared; the areas of brain hypoperfusion regions were measured. Pearson′s correlation coefficient was used to analyze the correlation between iodine density values and CBV values, iodine density values and CBF values, effective atomic number values and CBV values, effective atomic number values and CBF values, as well as hypoperfusion area shown on CTA images and displayed on CTP-CBF map.Results:Of all the 35 patients, the iodine density value [(0.22±0.07) mg/ml], effective atomic number value (7.38±0.05), CBV value [(1.9±0.7) ml/100 g] and CBF value [(15.1±5.9) ml/(100 g·min)] of the hypoperfusion area were significantly lower than those of the healthy side [iodine density value (0.44±0.10) mg/ml, effective atomic number value (7.52±0.06), CBV value (3.4±0.7) ml/100 g, CBF value (57±27) ml/(100 g·min); t values were -14.7, -14.5, -11.2, -9.7, respectively, all P<0.001]. No significant difference was found between the hypoperfusion area shown on spectral CTA [(2 292±1 393) mm 2] and shown on CTP-CBF map [(2 290±1 359) mm 2] ( t=-0.076, P=0.944). There was a positive correlation between iodine density value and CBV (affected side r=0.350, P=0.039, healthy side r=0.551, P=0.001); a positive correlation was also found between effective atomic number value and CBV (affected side r=0.488, P=0.003, healthy side r=0.552, P=0.001); and there was a strong positive correlation between the hypoperfusion area on CTA and that on CTP-CBF ( r=0.993, P<0.001). Conclusion:Dual-layer detector spectral CTA can provide the “one-stop” assessement including head and neck vascular evaluation, as well as the hypoperfution area measument, which can be an alternative rapid method for evaluation of patients with acute ischemic stroke.