Wellington Hospital faces spending an extra $2 million outsourcing scanning while it upgrades its radiology equipment.
The $13.6m upgrade is taking place over the next three years.
It disrupts how much interventional radiology can be done in-house, with excess scans to be outsourced, usually to a private provider.
"We will resume delivering these procedures onsite when the upgrade has been completed," said Te Whatu Ora Capital, Coast and Hutt Valley director of provider services Joy Farley.
The $2m is on top of the hospital's separate, large and expanding outsourcing bill for diagnostic radiology.
The hospital has said it is on track to spend $5m this way this year, instead of a budgeted $1.2m, and perhaps $7m next year.