Deputy State Coroner Derek Lee is trying to pinpoint what caused Baylen Pendergast’s injuries in mid-November 2013, and the medical response at Tamworth hospital, and whether there was a failure to properly diagnose head injuries or notify child protection authorities.

Baylen’s maternal grandmother Michelle Bryan was in and out visiting Baylen after he was admitted to Tamworth hospital on November 22.

When she was told by staff they wouldn’t transfer the little boy to Newcastle for an MRI she told the inquest, “I offered to drive him, and I was told that wouldn't work because we would be an outpatient". She said she felt “a bit helpless”.

She said “we were frantically trying to work out what was wrong with him" but were told “they couldn’t do anything” and “when we left [hospital], I was under the assumption it was basically just the gastro”.

Baylen was rushed back, unconscious to Tamworth hospital on November 28 and an autopsy revealed he died of head injuries.

Ms Bryan said her daughter, Zoe, was "very close, she was very protective" and “reasonably confident for a new mum, for a first time mum".

She said when she saw Baylen on November 17, after he had reportedly fallen and hit his head on his racing car bed, he was “bit quieter, he was up in his toybox, wandering around the loungeroom".

She said “he wasn't crying or miserable" but had a black eye and bruising, and “obviously it would have been really sore".

Dr Scott McIlveen was head of emergency at Tamworth hospital when Baylen first presented on November 22.

He told the inquest on Thursday that it was a “balancing exercise” to undertake an MRI scan on a two-year-old child because of the risks of “general anesthetic”. He said an MRI exposes children to “anesthetic injury” and CT-scans “are not easy” on a young child.

Baylen was released on a hospital gatepass on November 24, but Dr McIllveen said “the decision for discharge is not a decision I'm ordinarily involved in” because he was an emergency physician.

He said he was aware of the child risk assessment screen and agreed it would have been prudent for staff to contact him and have a discussion if they answered yes to any questions on the mandatory reporting checklist.

Rebecca Johnson was a registered nurse on the wards at Tamworth hospital in 2013.

Barrister for Baylen’s mother, Zoe, Philip Massey questioned nurse Johnson on the gatepass and the instructions on whether Baylen was ordered to return to the pediatric ward on November 24, or just to call in to report the child’s condition.

She told the inquest, “I can’t authorise a gatepass … that wasn’t my role”, but she said she didn’t “recall” Baylen’s father Luke Pendergast being present for the discussion.

“I just cannot see it's purpose ... it just does not have any medical benefit,” Mr Massey said in questioning on the gatepass.

“In this particular case, it's done everything to cause confusion.”

When questioned on the child assessment screen, nurse Johnson said her “understanding is a doctor or a nurse can certainly fill it out".

She acknowledged that she had not filled out the form, and it could have been done by the staff on the next shift and it is “one avenue of finding out the child’s social situation”.

She said the discussions with parents would involve the nursing care plan, “as part of my care for Baylen that would involve continually checking his vital signs”.

Coroner Lee is also examining what caused the 22-month-old to lose consciousness on November 28, before he was rushed to hospital and airlifted to Sydney, where his life support was switched off two days later.

The inquest will resume in Sydney in mid-April.