In diagosing pancreatitis, which is more useful, mri or ct? and are regular abodominal mri and ct different from mrcp or hida scan?

Each has its place: CT is the standard study for demonstrating pancreatitis but usually it can be diagnosed by blood test and clinical exam. CT is usually reserved for looking for complications. It's faster & cheaper than MRI or HIDA. MRI & HIDA are used to look for causes of pancreatitis, like obstructed ducts. Most cases of pancreatitis require only simple ultrasound to rule out obstruction, and no other studies.