It is possible to create an imaging result without a patient (and a patient can not be filled in because the field is read-only), which typically results in

Traceback (most recent call last):                                                                                                                                                                                                          
  File "/home/mathiasb/projects/gnuhealth4/trytond/trytond/protocols/dispatcher.py", line 182, in _dispatch                                                                                                                                 
    result = rpc.result(meth(c_args, *c_kwargs))                                                                                                                                                                                          
                        ^^^^^^^^^^^^^^^^^^^^^^^^^                                                                                                                                                                                           
  File "/home/mathiasb/projects/gnuhealth4/trytond/trytond/model/modelsql.py", line 870, in read                                                                                                                                            
    getter_results = field.get(                                                                                                                                                                                                             
                     ^^^^^^^^^^                                                                                                                                                                                                             
  File "/home/mathiasb/projects/gnuhealth4/trytond/trytond/model/fields/function.py", line 105, in get                                                                                                                                      
    return dict((name, call(name)) for name in names)                                                                                                                                                                                       
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^                                                                                                                                                                                       
  File "/home/mathiasb/projects/gnuhealth4/trytond/trytond/model/fields/function.py", line 105, in <genexpr>                                                                                                                                
    return dict((name, call(name)) for name in names)                                                                                                                                                                                       
                       ^^^^^^^^^^                                                                                                                                                                                                           
  File "/home/mathiasb/projects/gnuhealth4/trytond/trytond/model/fields/function.py", line 100, in call                                                                                                                                     
    return dict((r.id, method(r, name)) for r in records)                                                                                                                                                                                   
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^                                                                                                                                                                                   
  File "/home/mathiasb/projects/gnuhealth4/trytond/trytond/model/fields/function.py", line 100, in <genexpr>                                                                                                                                
    return dict((r.id, method(r, name)) for r in records)                                                                                                                                                                                   
                       ^^^^^^^^^^^^^^^                                                                                                                                                                                                      
  File "/home/mathiasb/projects/gnuhealth4/trytond/trytond/modules/health_imaging/health_imaging.py", line 170, in patient_age_at_evaluation 
    if (self.patient.name.dob and self.date): 

So generally 
- def patient_age_at_evaluation should handle this case gracefully with
        if (self.patient and self.patient.name.dob and self.date):
- Input of a patient and request_date should be possible to be able to enter manual Imaging Results otherwise the form is too workflow dependent (this would be my preference)
- If OTOH the whole form should only be readable for workflow results then the whole form should be read-only (currently e.g. Study and Evaluated By are editable)