与γ相机相比SPECT的性能优势？
参考答案：与γ相机相比，SPECT克服了平面显像时由于组织、器官放射性的重叠造成的体内小病灶的掩盖，提高了对深部病变的探测能力，提高了分辨力与定位能力。SPECT的准直器也作了很大的改进，新准直器的使用，增加了分辨力、提高了灵敏度；并能根据脏器的需要与显像方式的各异配置相应的准直器，出现了扇型、斜孔型、长颈型、椎型等准直器，使图像的质量有了很大的提高。随着计算机运算速度的提高、新影像处理软件的应用，SPECT可以为临床诊断提供更多的诊断参数与相对客观的诊断指标。
A child's birthday party doesn't have to be a hassle; it can be a basket of fun, according to Beth Anaclerio, an Evaston mother of two, ages 4 and 18 months. "Having a party at home usually requires a lot of running around on the part of the parents, and often the birthday boy or girl gets lost in wild excitement. But it really doesn't have to be that way," said Anaclerio. Last summer, Anaclerio and her friend Jill Garlisle, a Northbrook mother of a 2-year-old, founded a home party-planning business called "A Party in a Basket." Their goal is to help parents and children share in the fun part of party planning, like choosing the subject or making a cake, while they take care of everything. Drawing on their experiences as mothers, they have created（制作）10 ready-to-use, home party packages. Everything a family needs to plan a party, except the cake and ice cream, is delivered to the home in a large basket. "Our parties are aimed for children 2 to 10."Anaclerio said, "and they're very interactive（互动）and creative in that they build a sense of drama based on a subject. For example, at the Soda Shoppe party the guests become waiters and waitresses and build wonderful ice cream creations." The standard ＄200 package for eight children includes a basket filled with invitations, gifts, games and prizes, paper goods, a party planner and the like. For more information, call Anaclerio at 708-864-6584 or Carlisle at 708-205-9141. 72. The main purpose of writing this text is ____. A. to share information about party planning B. to introduce the joys of a birthday party C. to announce a business plan D. to sell a service 73. The most important idea behind the kind of party planning described here is that ____. A. it brings parents and children closer together B. guests play a part in the preparation of a party C. parents are spared the trouble of sending invitations D. it provides a subject of conversation 74. What does the underlined word "hassle"（Paragraph 1） probably mean？ A. a party designed by specialists B. a plan requiring careful thought C. a situation causing difficulty or trouble D. a demand made by guests 75. Which of the following is most likely to be a party planner？
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