fix: cannot access image_defs attributes like a dictionary. fix typo in test_diffusion_parameters_v4.

Author: grlee77

nibabel/parrec.py

@@ -703,7 +703,7 @@ def get_q_vectors(self):
             acquisition.
         """
         bvals, bvecs = self.get_bvals_bvecs()
-        if bvals is None and bvecs is None:
+        if bvals is None or bvecs is None:
             return None
         return bvecs * bvals[:, np.newaxis]
 
@@ -728,7 +728,7 @@ def get_bvals_bvecs(self):
         # All bvals within volume should be the same
         assert not np.any(np.diff(bvals, axis=0))
         bvals = bvals[0]
-        if 'diffusion' not in self.image_defs:
+        if 'diffusion' not in self.image_defs.dtype.names:
             return bvals, None
         bvecs = self.image_defs['diffusion'][reorder].reshape(
             (n_slices, n_vols, 3), order='F')

nibabel/tests/test_parrec.py

@@ -350,13 +350,13 @@ def test_diffusion_parameters_v4():
     assert_almost_equal(bvals, DTI_PAR_BVALS)
     # no b-vector info in V4 .PAR files
     assert_equal(bvecs, None)
-    assert_equal(dti_hdr.get_q_vectors(), None)
+    assert_equal(dti_v4_hdr.get_q_vectors(), None)
 
 
 def test_null_diffusion_params():
     # Test non-diffusion PARs return None for diffusion params
     for par, fobj in gen_par_fobj():
-        if basename(par) in ('DTI.PAR', 'NA.PAR'):
+        if basename(par) in ('DTI.PAR', 'DTIv40.PAR', 'NA.PAR'):
             continue
         gen_info, slice_info = parse_PAR_header(fobj)
         with suppress_warnings():