AAPM Medical Physics Practice Guideline 1.b: CT protocol management and review practice guideline

Reduced contrast dose for CT head studies during COVID-19-related contrast shortage: Lesson from a crisis

OBJECTIVE

Intravenous contrast injection protocol for certain CT studies at our institution was revised in June 2022 in response to the global shortage of iohexol. This included CT head studies performed for neuro-navigation (contrast dose from 90 mL to 70 mL). The quality of these studies was assessed.

METHODS

Consecutive CT scans before (n = 32) and after (n = 32) contrast dose reduction were reviewed. Demographic data was obtained from the chart. Subjective observations made by two radiologists in consensus included overall study quality (Likert scale of 1 to 5) and lesion location, margins and internal characteristics that were compared with MRI findings (reference standard) using Fisher's exact test. Superior sagittal sinus attenuation, used as an objective measurement of enhancement, and lesion size were compared using Student's t-test. The institutional database was searched for any study requiring repetition or deemed non-diagnostic.

RESULTS/DISCUSSION

The average age (61.1 ± 12.7 years and 61.6 ± 14.9 years) and body surface area (BSA) (1.9 ± 0.3 m2 and 1.9 ± 0.02 m2) was not significantly different (p > 0.05) between groups. There was no significant difference (p > 0.05) in objective or subjective enhancement between the two groups. There was no significant difference between CT and MRI for lesion size, location, number, margins and internal enhancement characteristics in the two groups. No study required repetition or was reported as non-diagnostic. There was no adverse comment about study quality in operative notes.

CONCLUSION

Reduced contrast dose neuro-navigation CT head studies are not different in quality compared to the conventional studies.

Assessment of radiographers' knowledge about radiation doses and DRLs in computed tomography departments in Jeddah, Saudi Arabia: A cross-sectional study

Objective

To assess radiographers' understanding of radiation safety considering the newly approved national diagnostic reference levels (DRLs) as an optimization tool for radiation dose.

Methods

A cross-sectional study was conducted in Saudi Arabia among radiographers working at local hospitals in Jeddah city from February to March 2022. The survey comprised of 22 questions involving demographic information; and general information related to radiation dose; CTDIvol and DRLs. Data were analyzed using IBM SPSS Statistics version 26. Chi-square test was used to compare demographic groups regarding their distribution of responses with 0.05 as the level of significance.

Results

A total of 169 radiographers participated in the study (39 % females, 60 % males). Most of the participants (91 %) were aware of the description of the ALARA principle. It was noted that (47 %) of the participants indicated that the routine scanning protocols are designed by the radiologists. The majority of them (78 %) were confident to manipulate the CT scanning parameters properly. In addition, half of the participants (53 %) were aware of the CTDIvol and DLP. Unexpectedly, none of the demographic variables were significantly associated with the radiographers' knowledge about radiation dose, p-values are > 0.05.

Conclusion

Although radiographers demonstrated good knowledge of radiation protection, limited awareness of DRLs was noted among radiographers and lack of implementing and optimizing the local dose of the DRLs in this study. Therefore, education and training for healthcare professionals including radiographers are necessary to enhance clinical practical performance in radiology departments.

Challenges Associated with Effective Implementation of CT Dose Check Standards and Radiation Monitoring Index in Computed Tomography: Healthcare Sector Experience

Computed tomography (CT) radiation dose management tools should be used whenever possible, particularly with the increasing demand for acquiring CT studies. Herein, we aim to assess the advantages and challenges faced with implementing two CT dose management tools. A second aim was to highlight CT examinations exceeding dose notification values (NVs) and define the common set of causes. A total of 13,037 CT examinations collected over a six-month period, were evaluated, using two independent CT dose management tools, a CT Dose Notification prospective-view tool (PVT) following CT Dose Check standards and a retrospective statistical-based view tool (RSVT). Dose NVs were set to twice the Local Diagnostic Reference Levels. There was a significant discrepancy between dose NV counts registered with prospective (4.15%) and retrospective (7.98%) tools using T-Test. A core difference is the dose configuration setup, with PVT and RSVT being dose per series and whole study, respectively. Both prospective and retrospective dose management tools were equally useful despite their technical difference. Configuring the CT prospective dose notification check tool using NVs that is based on DRLs has limitations, and one needs to establish dose NVs per series to overcome this technical hurdle. Technical challenges make the implementation of CT Dose Check standards puzzling.