正常听力国人听觉皮层频率分布的功能MRI研究  

The Tonotopic Map of Auditory Functional MRI in Normal Hearing Subjects

作　　者：高薇薇[1] 杨明[2] 夏贵华[1] 刘斌[2] 黄志纯[3] 

机构地区：[1]浙江大学医学院附属第一医院北仑分院耳鼻咽喉科,宁波315806 [2]东南大学附属中大医院放射科 [3]东南大学附属中大医院耳鼻咽喉科

出　　处：《听力学及言语疾病杂志》2009年第5期444-447,共4页Journal of Audiology and Speech Pathology

基　　金：东南大学科技基金项目(KJ0790300);973项目(2007CD512303)资助

摘　　要：目的利用血氧水平依赖功能磁共振成像(BOLD-f MRI)研究正常听力国人的听皮质频率响应分布的特点。方法对25例健康受试者采用事件相关Sparse设计、正弦调幅音任务下的回波平面成像技术(echoplanar imaging,EPI)进行f MRI数据采集,实验刺激声分别为0.5、2、4kHz纯音经8Hz正弦调幅,双耳同时间断给声,给声持续时间9s,扫描3s,随机插入静音序列。利用SPM2软件进行数据分析,观察左右大脑听觉皮层频率响应分布特点。结果25例受试者中9例由于EPI采集时头动超过最大限度而删除数据,余16例受试者均表现为初级听觉皮层激活,其中2例左侧、3例右侧、4例双侧初级听觉皮层激活的部位表现出高频偏内、低频偏外的频率响应分布特点,另7例双侧初级听觉皮层无明显的排列规律。结论正常听力国人初级听觉皮层的频率响应分布表现出高频偏内、低频偏外的特点。Objective The functional MRI （fMRI） was measured in the normal hearing Chinese subjects in responses to stimulations of different frequencies to investigate the tonotopie map in primary auditory cortex. Methods 25 healthy subjects with normal bearing were examined using tones of 500, 2 000 or 4 000 Hz that were amplitude modulated （AM） sinusoidally at 8 Hz. The AM signals were presented at 96 dB SPL. Event-related design was combined with a sparse clustered volume acquisitioning paradigm for data collection in the attempt to reduce the influence of acoustic scanner noise. SPM2 software was used for offline data analyzing. Results Data from 9 subjects were discarded due to a large head movement during recording. In the rest 16 subjects, activation was found mainly in the primary auditory cortex. In many cases （6 left and 7 right hemispheres）, a lateral-medial preference for low-to-high frequency response shift was clearly demonstrated in the primary auditory cortex. Conclusion Regarding stimulus frequencies, low-to-high frequency spatial gradients were observed along the primary auditory cortex in anterolateraI to posteromedial direction, consistent with the presence of a tonotopic map in these primary areas.

关 键 词：频率响应分布 功能磁共振 听觉皮层 音频定位结构 

分 类 号：R814.42[医药卫生—影像医学与核医学]