theta1=0:0:170确实有问题，应该改为theta1=0:10:170.表示R1采用18个投影。你说的保存为.***文件格式，下拉菜单里确实没有这种格式，这种格式的图片我也没有拿来做过实验。至于生成三维头盖骨模型，呼唤热心人....

'Shepp-Logan'            A test image used widely by researchers in

tomography

'Modified Shepp-Logan'   (default) A variant of the Shepp-Logan phantom

in which the contrast is improved for better

visual perception.

N is a scalar that specifies the number of rows and columns in P.

If you omit the argument, N defaults to 256.

P = PHANTOM(E,N) generates a user-defined phantom, where each row

of the matrix E specifies an ellipse in the image.  E has six columns,

with each column containing a different parameter for the ellipses:

Column 1:  A    the additive intensity value of the ellipse

Column 2:  a    the length of the horizontal semi-axis of the ellipse

Column 3:  b    the length of the vertical semi-axis of the ellipse

Column 4:  x0   the x-coordinate of the center of the ellipse

Column 5:  y0   the y-coordinate of the center of the ellipse

Column 6:  phi  the angle (in degrees) between the horizontal semi-axis

of the ellipse and the x-axis of the image

For purposes of generating the phantom, the domains for the x- and

y-axes span [-1,1].  Columns 2 through 5 must be specified in terms

of this range.

[P,E] = PHANTOM(...) returns the matrix E used to generate the phantom.

Class Support

-------------

All inputs must be of class double.  All outputs are of class double.

Remarks

-------

For any given pixel in the output image, the pixel's value is equal to the

sum of the additive intensity values of all ellipses that the pixel is a

part of.  If a pixel is not part of any ellipse, its value is 0.

The additive intensity value A for an ellipse can be positive or negative;

if it is negative, the ellipse will be darker than the surrounding pixels.

Note that, depending on the values of A, some pixels may have values outside  the range [0,1].

目前我所知道也就这么多，也在学，学得越多才知道自己会的越少....请问你是医学图像处理的吗？