Current Australian national diagnostic reference levels for multi detector computed tomography

Australian Adult (15+ years) MDCT DRLs

The current DRLs for MDCT scans on adult patients are shown below (Table 1) and were last updated in March 2021. Information relating to the development of the DRLs and on transitional arrangements for the most recent update can be found on the 2021 MDCT update and the MDCT statistics pages.

Table 1: Multi detector computed tomography diagnostic reference levels for adults

Notes:

1. Diagrams of the scan regions and additional protocol information are available from the before you enter data page.
2. The scans included in a dose comparison do not necessarily have to be for the listed phase/indication; however, the exposure parameters of the included scans must match what would be used for the listed phase/indication.
3. Dose indices for the Head region are based on the 16 cm reference phantom. Dose indices for all other scan regions are based on the 32 cm reference phantom.

Adult (15+ years) MDCT reference level quartiles

The following tables provide additional information on the observed distributions of facility reference levels (FRLs). An FRL is the median dose reported in a survey of patient dose for a specific scan region, on a specific scanner, at a specific facility. These tables are provided for information only – there is no regulatory requirement for facilities to compare their FRLs to them.

Table 2 shows the rounded 25th and 50th percentiles of the FRL distributions and compares them to the national DRLs. Facilities can use this additional information to gain a better understanding of how their FRLs compare to those of other facilities. If your FRL is near the 50th percentile you are approximately consistent with most other sites. If your FRL is below the 25th percentile you are amongst the lowest dose sites. It is important to ensure that the image quality in your scans is sufficient for the clinical task.

Table 2: FRL distribution percentiles and diagnostic reference levels (DRLs)

^{Footnote: The percentiles are derived from data submitted to the ARPANSA National Diagnostic Reference Level Service (NDRLS) in 2017, except in the case of cervical spine, soft-tissue neck, and kidney-ureter-bladder scans where the percentiles are derived from data submitted in 2019. Analysis of the most recent data can be found on the MDCT Statistics page.}

Table 3: Iterative reconstruction FRL distribution percentiles

Table 4: Filtered back projection FRL distribution percentiles

Table 5: Comparison of the diagnostic reference levels (DRLs) and the 75th percentile of the FRL for surveys conducted using filtered back projection (FBP) and iterative reconstruction (IR)

Australian child (5-14 years) MDCT DRLs

For more information see the MDCT statistics page.

Australian baby/infant (0-4 years) MDCT DRLs

For more information see the MDCT statistics page.