Access to viewing diagnostic images has finally been restored at England’s largest trust, nine days after a major computer network failure downed a series of essential clinical IT systems at the trust.

Barts Health NHS Trust had to cancel 136 operations and several hundred chemotherapy appointments from 20 April to 2 May after a “major computer equipment failure”.

In a statement released on Tuesday, the trust said pathology, imaging and chemotherapy prescribing were now working.

“We have made significant progress in many areas including pathology (blood testing), with chemotherapy prescribing and image viewing now restored across the Trust. There are still some other areas where it will take time before we are on track again.”

The trust said clinical teams are conducting a patient-by-patient review, and apologised to those affected with promises of rescheduled appointments.

Barts added that the trust was using “tried and tested contingency plans to keep our patients safe”.

In a statement, released on Friday when imaging and pathology were still operating an incomplete service, the trust said images were being accessed through a web-based tool.

The severity of the incident was also indicated through Barts offering reassurance that “we have not lost our historic archive of images”.

The trust did not confirm to Digital Health News on Tuesday further details on the cause of the crash.

However, a spokeswoman confirmed that work is on-going to “restore non-clinical applications”.

This incident is the second time this year that Barts has been hit with a major network incident affecting services across the trust for more than a day.

In January, Barts was hit by an “IT attack”, with systems taken down for four days. The trust said the attack was caused Trojan malware.

Barts, the largest NHS trust in England, was created in April 2012, and serves 2.5 million people living in East London across four hospital sites – The Royal London, St Bartholomew’s, Whipps Cross and Newham University Hospital.

The trust has been beset by financial problems, with a deficit of £135 million, and regulators have criticised the quality of services.

In a Care Quality Commission report, released 28 April, Newham was rated as “requires improvement” overall, with “some improvement” noted in electronic patient records.

Alwen Williams, chief executive at Barts, said in a statement that she was pleased with the positive progress at the hospital but also apologised to patients.

“The CQC also rightly observed areas where we still have work to do, and I am sorry for instances where we have let patients down.”

In September 2016  Leeds Teaching Hospitals NHS Foundation Trust, another extremely large hospital trust created through a series of mergers, suffered a failure its pathology IT system that led to weeks of disruption across the city with 143 non-urgent procedures postponed and disrupted regional blood services.

A subsequent independent review of the Leeds incident blamed the protracted crash on human error and ageing infrastructure.