关键词: 三维时间飞跃法; 磁共振血管成像; 微出血; 脑

Abstract: Objective To study the value of source images of three dimensional time-of-flight magnetic resonance angiography(3D-TOF MRA) in detecting cerebral microbleeds(CMBs) in brain parenchyma.Methods Two hundred and eighty patients who were suspected to have microbleeding lesions were recruited. T2* gradient recall echo(GRE) sequence and 3D-TOF MRA sequences were performed after routine magnetic resonance(MR) head imaging were performed. Numbers, location, and scales of CMBs on 3D-TOF MRA axial source images and T2*GRE images were compared.Results Seven-five cases were proved to have CMBs by T2*GRE sequence. Nine cases which could not be compared were excluded. On T2*GRE images, three hundred and thirty eight CMBs were found with 50 cases as grade 1, 10 cases as grade 2, and 6 cases as grade 3. On 3D-TOF MRA source images, two hundred and forty two CMBs were found with 11cases as grade 0, 40 cases as grade 1, 12 cases as grade 2, and 3 cases as grade 3. Paired-sample t test showed that there were significant difference between CMBs found by two methods at cortical/subcortical area(P=0.000), thalami(P=0.001), and cerebellum(P=0.039), while no significant difference were found between CMBs found by two methods at basal ganglia(P=0.581) and brain stem(P=0.211). Consistency of two different sequences showed Kappa value was 0.494(P=0.092).Conclusion Source images of 3D-TOF MRA can be used to detect CMBs. Though CMBs on 3D-TOF MRA source images were not as clear as those on T2*GRE images, when T2*GRE images are absent, 3D-TOF MRA source images may be helpful to display microbleeds lesions and suggest further examination.

Key words: Three-dimensional time of flight; Magnetic resonance angiography; Microbleeds; brain