From the Guidelines
Aortic Aneurysm Measurement on PET Scan
Aortic aneurysm can be incidentally measured on a PET scan, particularly when using the CT component of PET/CT hybrid imaging 1.
- The CT component of PET/CT can provide accurate measurements of the aneurysm's diameter, although it is not the primary modality for diagnosing or measuring abdominal aortic aneurysms (AAAs) 1.
- FDG-PET/CT can play a role in the diagnosis of inflammatory and mycotic aortic aneurysms and in predicting risk for AAA rupture, but its use is not primarily for measuring aneurysm size 1.
- Other imaging modalities such as ultrasound, CT angiography, and MR angiography are more commonly used and recommended for the evaluation and follow-up of AAAs due to their high accuracy and reproducibility in assessing aneurysm size and growth rate 1.
- The use of PET/CT for measuring aortic aneurysms is not a standard practice and is generally not recommended as the primary imaging modality for this purpose 1.
From the Research
Aortic Aneurysm Measurement on PET Scan
- The studies 2, 3, 4, 5, 6 suggest that Positron Emission Tomography (PET) scans can be used to detect and measure aortic aneurysms.
- The use of 18F-fluorodeoxyglucose (FDG) PET/CT scans has been shown to be effective in detecting increased metabolic activity in the wall of abdominal aortic aneurysms (AAAs) 2, 3.
- FDG-PET/CT scans can provide information on the inflammation, aortic wall instability, and acute symptoms associated with AAAs 2.
- The maximum standard uptake values (SUV(max)) can be calculated to determine the metabolic activity of the aneurysm 2, 3.
- PET/CT scans can also be used to detect type II endoleaks after endovascular aneurysm repair (EVAR) 5.
- The imaging features of mycotic aortic aneurysms, including lobulated pseudoaneurysm, indistinct irregular arterial wall, and high metabolic activity with increased uptake of FDG, can be detected using PET/CT scans 6.
Limitations and Considerations
- The studies 2, 3, 4, 5, 6 have limitations, including small sample sizes and variability in imaging protocols.
- The use of PET/CT scans for aortic aneurysm measurement may not be suitable for all patients, particularly those with contraindications for FDG or CT contrast media.
- Additional imaging modalities, such as CT angiography or MRI, may be necessary to confirm the diagnosis and guide treatment.
Key Findings
- Increased FDG uptake is associated with inflammation, aortic wall instability, and acute symptoms in AAAs 2.
- FDG-PET/CT scans can detect type II endoleaks after EVAR 5.
- PET/CT scans can provide information on the imaging features of mycotic aortic aneurysms, including high metabolic activity with increased uptake of FDG 6.