Getting empty vector to polyfit, using ACRMRILarge

[emilchristensenku]

Dear all,

I am currently running the ACR analysis using the package from pylinac.
On the site specific sequence I get this error:
ile ~/opt/anaconda3/lib/python3.9/site-packages/spyder_kernels/py3compat.py:356 in compat_exec
exec(code, globals, locals)

File ~/Desktop/ACR_test.py:34
acr.analyze()

File ~/opt/anaconda3/lib/python3.9/site-packages/pylinac/core/warnings.py:43 in wrapper
result = method(self, *args, **kwargs)

File ~/opt/anaconda3/lib/python3.9/site-packages/pylinac/acr.py:1288 in analyze
self.localize()

File ~/opt/anaconda3/lib/python3.9/site-packages/pylinac/core/warnings.py:43 in wrapper
result = method(self, *args, **kwargs)

File ~/opt/anaconda3/lib/python3.9/site-packages/pylinac/acr.py:1194 in localize
self._phantom_center_func = self.find_phantom_axis()

File ~/opt/anaconda3/lib/python3.9/site-packages/pylinac/ct.py:2153 in find_phantom_axis
np.polyfit(zs[common_idxs], center_xs[common_idxs], deg=1, rcond=0.00001)

File ~/opt/anaconda3/lib/python3.9/site-packages/numpy/lib/polynomial.py:639 in polyfit
raise TypeError("expected non-empty vector for x")

TypeError: expected non-empty vector for x

As far as I can understand from the code, it is because the code cannot find a phantom of the correct size as it expects. The sequence i have used is of size 192x256, with a FOV of 195x260. Making the image smaller than the original ACR sequence.