患者男性，40岁，体检头颅CT发现左顶部4．0cm×3．0cm囊性肿块，患者否认有外伤史，否认高血压、糖尿病病史，其他实验室检查未见明显异常，体格检查未见阳性体征。
关于影像学分析下列哪些是正确的（）
A.囊壁有无钙化有助于皮样囊肿与蛛网膜囊肿鉴别
B.占位效应有助于皮样囊肿与蛛网膜囊肿的鉴别
C.壁有无强化对皮样囊肿与蛛网膜囊肿的鉴别无帮助
D.周围有无水肿有助于皮样囊肿与星形细胞瘤的鉴别
E.若囊性肿块壁厚有钙化，无瘤周水肿，增强后无强化，可能为皮样囊肿
参考答案：A, C, D, E
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| On a hot summer day in south Florida, a little boy decided to go for a swim in the old swimming hole behind his house. In a hurry to dive into the cool water, the boy did not 1 that as he swam toward the middle of the lake, a 2 was swimming toward the shore. His mother, who was in the 3 , was looking out of the window and saw the two as they got closer together. In great 4 , she ran toward the water, yelling to her son as loudly as she could. Hearing her voice, the little boy became alarmed and made a (n) 5 to swim to his mother. It was too 6 . Just as he reached her, the crocodile reached him. From the dock, the mother grabbed her little boy by the 7 just as the crocodile snatched his legs. Then 8 an incredible tug-of-war between the two. The crocodile was much 9 than the mother, but the mother was much too passionate to let go. A farmer happened to drive by, heard her screams, raced from his truck, took his 10 and shot the crocodile. Remarkably, after weeks in the hospital, the little boy 11 His legs were extremely scarred by the attack, and, on his arms, were deep scratches where his mother's fingernails 12 his flesh in her effort to hang on to the son she loved. When a newspaper reporter who 13 the boy asked if he would show him his scars, the boy lifted his pant legs. And then, with obvious pride, he said to the reporter, "But look at my arms. I have great 14 on my arms, too. I have them because my mom wouldn't 15 ." | ||||
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