Scan logistics explained

Photo: Getty Images

Chris Fleming

There has been an average annual increase in requests for CT at Dunedin Hospital of 5% since 2013.

Much of this increase has in recent years been with emergency patients, which have increased by an average of 7.3% over the same period.

Emergency patient examinations tend to be required urgently. They also tend to take longer ... owing to the condition of the patient and also often the complexity of the examination required.

This reduces the time available for other patients.

Complex procedures are performed in CT, further limiting time available for lower-priority diagnostic examinations.

How many CT scanners are there in Dunedin Hospital?

The radiology unit has one dedicated diagnostic CT scanner. This is situated in a purpose-built facility.

There is a second scanner located in the oncology department. This is used for radiotherapy planning and is used most days, but owing to its distance from radiology its use adds considerable time to inpatient or emergency examinations. This scanner is not suitable for procedures and after-hours elective scanning is also problematic from a staffing perspective. Therefore, Radiology has elected to use additional staffing funded by the DHB to extend hours available for outpatient examinations on the main scanner.

There is also capacity to use the nuclear medicine scanner to undertake CT examinations. This equipment is slow and not designed for use as a frontline CT scanner.

How many people does it take to do one CT scan in Dunedin Hospital?

It varies, depending on the type of examination required. For example, an after-hours examination may be undertaken by a minimum of one medical imaging technologist and a radiology registrar, with support from a radiologist, who may attend in person, depending on the complexity of the case.

During heavy demand periods, a nurse may also assist. Orderlies will deliver the patient, usually accompanied by a nurse or healthcare assistant. If the patient is extremely unwell, several members of the referring team may also attend the examination.

When operating with a full staff complement, there are two nurses, two medical imaging technologists, a radiology registrar and a radiologist.

When CT is very busy, a third medical imaging technologist may be required to further reduce turnaround time.

How many of each of those staff does the SDHB have at Dunedin Hospital?

Southern DHB has a headcount of 10 CT-trained medical imaging technologists, 10 radiology registrars, nine radiologists working in CT and 12 nurses, each of whom are rostered into CT.

How frequently is the Dunedin Hospital machine in use?

The time for a procedure ranges from 10 minutes to three hours.

In the 12 months to February 2020,

there was a daily average of 9.5 emergency examinations and 8.5 inpatient examinations.

Elective and surveillance examinations in the same period were available for 250 days — giving an average of 11 per day of operation. Since then, the average number of elective appointments per day has increased..

How many CT scanners does the SDHB have outside Dunedin?

One at Southland Hospital and the other at Queenstown Lakes District Hospital.

Southland Hospital also has a nuclear medicine scanner.

How frequently are those machines in use?

Both machines operate 24/7, 365 days a year for acute and inpatient examinations and 250 days a year for outpatient examinations. Southland has recently introduced an evening shift similar to the Dunedin one, but is yet to introduce outpatient scanning in the evening.

Could people from Dunedin be sent to other places for a scan?

Yes. Patients referred for CT at Dunedin Hospital are routinely offered scans at Oamaru, Southland Hospital, Dunstan, Pacific Radiology in Dunedin and most recently at Lakes District Hospital.

How do you triage patients for use of the CT scanner, and how many people who are not in the top priority category are getting scans on a usual day?

All outpatient referrals are prioritised by a radiologist who assigns a triage category.

This is based on the time the patient could reasonably be expected to wait before their condition may deteriorate.

Cancer staging scans are, for example, given a higher priority than other urgent scans because of the time-sensitive nature of the request.

Emergency and inpatient requests are prioritised at the time of referral and reprioritised throughout the day as new referrals come in.

At times, we have more inpatient and emergency demand in a day than can be scanned. Consequently, the radiology service has to postpone the outpatients scheduled for the day or later in the week.

A new CT scanner has been approved and ordered. When will it be installed? When will it be operational?

Building work is required to provide a space to install an additional scanner.

This is expected to be completed on July 30. This is also the time when the new scanner is expected to arrive in Dunedin.

From there, a three-week period is required to install the equipment, commission it and train staff.

Approval was given last year to hire staff to operate the new scanner. How many extra staff need to be hired? How many have been hired?

Most of the staff required to operate the additional CT scanner in radiology are already employed in the service. However these staff are not all rostered into CT at once and work in other areas of radiology. Some additional staffing is required to free up CT staff to work on the new scanner, as well as some additional nursing and administration capacity including an additional medical imaging technologist, a registered nurse and a radiology assistant. The initial stages of the recruitment process have begun.

Once the second machine and staff are in place, will that solve the delay problem?

An additional scanner will allow the radiology department to separate elective from inpatient and emergency patients, as well as procedures.

Even at a rate of three per hour, Dunedin could complete 24 elective examinations each working day or 6000 elective examinations per annum.

That compares with 4950 requests in 2020 (1790 of which were scanned at sites other than Dunedin). This should provide sufficient capacity for the wait list at Dunedin to recover.