PAR/REC Changes for Philips Software R11

My site has just upgraded our scanner from software release R5.9 to R11. When I've tried to read in the test data I acquired I get the following error: ``` File "c:\Users\ppzajd\Desktop\Temp\nibabel_testing\nibabel_r11_test.py", line 5, in <module> r11_img = nib.load('R11_T2W_TSE.PAR') ^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\ppzajd\Git\nibabel\nibabel\loadsave.py", line 114, in load img = image_klass.from_filename(filename, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\ppzajd\Git\nibabel\nibabel\parrec.py", line 1332, in from_filename return klass.from_file_map( ^^^^^^^^^^^^^^^^^^^^ File "C:\Users\ppzajd\Git\nibabel\nibabel\parrec.py", line 1295, in from_file_map hdr = klass.header_class.from_fileobj( ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\ppzajd\Git\nibabel\nibabel\parrec.py", line 767, in from_fileobj info, image_defs = parse_PAR_header(fileobj) ^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\ppzajd\Git\nibabel\nibabel\parrec.py", line 524, in parse_PAR_header general_info = _process_gen_dict(gen_dict) ^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\ppzajd\Git\nibabel\nibabel\parrec.py", line 351, in _process_gen_dict props = _hdr_key_dict[key] ~~~~~~~~~~~~~^^^^^ KeyError: 'Max. number of Diffusion values' ``` Having done a bit of debugging it seems that Philips have _helpfully_ capitalised the D of diffusion in the general information key of the PAR files in this software release i.e. the old PAR files was ``` # === GENERAL INFORMATION ======================================================== # . Patient name : R_5_Data ... . Diffusion echo time [ms] : 0.0000 . Max. number of diffusion values : 1 . Max. number of gradient orients : 1 ``` and is now ``` # === GENERAL INFORMATION ======================================================== # . Patient name : R_511_Data ... . Diffusion echo time [ms] : 0.0000 . Max. number of Diffusion values : 1 . Max. number of gradient orients : 1 ``` From a quick look at the nibabel code it looks to me like the easiest solution would be to make the key matching with `_hdr_key_dict` case insensitive. I have a draft solution that seems to be working by changing the [_process_gen_dict](https://github.com/nipy/nibabel/blob/b5ecf482648aac5c77630d0d65555f043fc5d757/nibabel/parrec.py#L346) function as below. ``` python def _process_gen_dict(gen_dict): """Process `gen_dict` key, values into `general_info`""" general_info = {} for key, value in gen_dict.items(): # get props for this hdr field # Match key in _hdr_key_dict case-insensitively props = None for dict_key in _hdr_key_dict: if dict_key.lower() == key.lower(): props = _hdr_key_dict[dict_key] break # turn values into meaningful dtype if len(props) == 2: # only dtype spec and no shape value = props[1](value) elif len(props) == 3: # array with dtype and shape value = np.fromstring(value, props[1], sep=' ') # if shape is None, allow arbitrary length if props[2] is not None: value.shape = props[2] general_info[props[0]] = value return general_info ``` I'm happy to work on this in a PR but thought it was worth opening an issue first to check maintainers are happy with my proposed solution before I invest any more time (especially as this would be my first contribution to nibabel). I can provide more information/test data if that's helpful.