There were concordant results between the reviewing radiologist and resident in 85.4 percent of the cases, according to the researchers. They also noted no LAP-specific findings that contributed to clinical management of the patients.
“Our findings … suggest that a portal venous phase (PVP)-only protocol may be sufficient to address the relevant clinical question in patients with undifferentiated abdominal pain, while additional arterial imaging should be reserved for specific diagnostic indications,”noted lead study author Roland Cronenberg, MD, who is affiliated with the Department of Biomedical Imaging and Image-Guided Therapy at the Medical University of Vienna in Vienna, Austria, and colleagues.
Key Findings with Radiation Dosing in CT Imaging of Acute Abdominal Pain
The researchers emphasized that employing low-kV techniques can facilitate enhanced views of hypervascular and hypovascular abnormalities in parenchymal abdominal organs as well as significant reductions in CT radiation dosing.
Additionally, out of the total mean dose-length product (DLP) of 501.5 mGy*cm for the study, the mean DLP values for LAP and PVP were 204.6 mGy*cm and 296.9 mGy*cm respectively.
Three Key Takeaways
• A PVP-only protocol may be enough for most undifferentiated acute abdominal pain. Low-kV portal venous phase (PVP) imaging alone achieved average sensitivity, specificity and accuracy of 91.5 percent, 81.25 percent and 90.6 percent, respectively, for detecting relevant pathology. No late arterial phase (LAP) findings contributed to clinical management.
• Dropping routine arterial imaging can meaningfully cut radiation dose. The late arterial phase accounted for 40.8 percent of the total dose-length product (mean 204.6 of 501.5 mGy*cm). Omitting it when it adds no clinically relevant information could substantially reduce radiation exposure.
• Arterial phase imaging still has a defined role. The authors recommend keeping it for suspected active bleeding or vascular pathology and for patients older than 75.
“In our cohort, the LAP accounted for 40.8% of the total dose-length product, corresponding to a mean estimated effective dose of approximately 3.1 mSv. Therefore, avoiding routine acquisition of the LAP when it does not provide additional clinically relevant information could substantially reduce radiation exposure,” maintained Cronenberg and colleagues.
The study authors cautioned that there may be increased image noise when employing reduced tube voltage, and that this may be more pronounced in those with larger body habitus. They also emphasized the necessity of arterial imaging in cases involving suspicion of active bleeding or vascular pathology, and for patients older than 75.
(Editor’s note: For related content, see “Improving Adherence to Best Practices for Incidental Abdominal Aortic Aneurysms on CT and MRI,” “Emerging Advances in Photon-Counting Computed Tomography” and “FDA Clears AI-Powered Triage Software for 10 Findings on Abdominopelvic CT.”)
Beyond the inherent limitations of a single-center retrospective study, the authors noted the possibility of incomplete clinical information for some cases and acknowledged that patients with vascular emergencies were underrepresented in the cohort. The researchers also conceded that the cohort was drawn from a tertiary care facility, which may limit application of the study findings to broader patient populations.
