- Could you tell me_______？

- Every four years.

A．how often the Olympic Games take place

B．when the Olympic Games are held

C．how often are the Olympic Games held

D．how often the Olympic Games were held

患者，女，28岁。1个月前开始无明显诱因反复出现胸闷、胸痛，再次发作半分钟至数分钟不等。胸痛以左胸部刺痛为主，无放射痛。每次发作可自行缓解，与体力活动关系不大，无头昏头痛、心慌、大汗等不适。曾自行服用"美托洛尔（倍他乐克）"自觉症状较前减轻，为进一步诊治，来院就诊。经查，血常规、血生化无异常。心脏超声、ECG及冠脉造影未见明显异常。

此时若需进一步检查，以下何种方式最优（）

A.胸部X片

B.CT

C.SPECT心肌灌注断层显像

D.MRI

E.SPECT心血池显像