The manager of the imaging directorate which runs a breastscreening unit under investigation by the Commission for Health Improvement has announced her resignation.

Nuala Martin is quitting as directorate manager at Hammersmith Hospitals trust, which manages the West of London breast-screening service at its Charing Cross Hospital. The service was suspended in June after it proved incapable of adhering to the national reporting protocol, and is unlikely to restart until at least October.

After clerical recall errors were discovered in patients' files earlier this year, an external audit of over 100,000 files was undertaken and CHI was called in to investigate. The breast-screening unit is attempting to contact the last of those women whose files were found to contain clinical errors.

Ms Martin is responsible for providing managerial support to the clinical director of the screening service.

The directorate has been the subject of three internal and external investigations over the past three years, after allegations of mismanagement and concerns over patient safety problems.

Ms Martin will leave the trust in mid-November, shortly after the early retirement of chief executive John Cooper, to take up a private sector post as a director of business development.

Mr Cooper last week told HSJ he had concerns about the management of the screening service.

But in a statement to HSJ this week, he made it clear he was proud of Ms Martin's record. He said: 'She has made an outstanding contribution to the trust during her 14 years here, particularly over the installation of our world-leading PACS system, which led to the Hammersmith becoming the first filmless hospital in Europe.

'She has also been responsible for a comprehensive re-equipment programme at Charing Cross.

'We very much regret that her expertise will be lost to the NHS, but appreciate her decision to develop her career and wish her all the best in the future.'