From the Guidelines
Spiral computed tomography (CT) angiography is the preferred method for diagnosing pulmonary embolism (PE) due to its high sensitivity and specificity, especially for detecting emboli in the main, lobar, and segmental pulmonary arteries. The diagnostic accuracy of spiral CT for PE has been a topic of debate, with initial studies reporting sensitivities and specificities approaching 100% compared to pulmonary angiography as the gold standard 1. However, more recent studies have reported a range of sensitivities (53% to 89%) and specificities (78% to 100%) for spiral CT angiography in the evaluation of PE 1.
The reasons for this apparent heterogeneity in diagnostic accuracy include differences in study design, investigator experience with spiral CT, and the anatomic extent of the pulmonary vascular tree studied 1. Spiral CT provides excellent results for the detection of emboli located in the main, lobar, and segmental pulmonary arteries, but its sensitivity is limited for detecting emboli in subsegmental and more peripheral arteries 1.
In clinical practice, spiral CT angiography is a valuable tool for diagnosing PE, especially in patients with a high pre-test probability of disease. The use of additional imaging rendering tools, such as cine viewing, multi-planar, and three-dimensional image analysis, can help improve the diagnostic accuracy of spiral CT angiography 1. The choice of imaging modality should be based on the individual patient's clinical presentation, risk factors, and the availability of imaging technologies.
The incidence of PE in the cohort of patients investigated can also influence the accuracy of spiral CT angiography, with higher incidence rates leading to better diagnostic performance 1. In patients with a low pre-test probability of PE, a negative spiral CT angiogram can help rule out the disease, while a positive result can confirm the diagnosis 1.
Overall, spiral CT angiography is a reliable and convenient method for diagnosing PE, especially in patients with a high pre-test probability of disease. Its high sensitivity and specificity make it a valuable tool in clinical practice, and its use can help improve patient outcomes by facilitating early diagnosis and treatment.
From the Research
Spiral and Aggregometry
- The concept of spiral and aggregometry is related to the assessment of platelet function, particularly in the context of antiplatelet therapy [(2,3,4,5,6)].
- Aggregometry is a laboratory test used to measure the ability of platelets to aggregate, or clump together, in response to various stimuli [(2,3,5,6)].
- There are different types of aggregometry, including light transmission aggregometry, whole-blood aggregometry, and multiple electrode impedance aggregometry [(2,3,5,6)].
Types of Aggregometry
- Light transmission aggregometry is a widely used method that measures the change in light transmission as platelets aggregate [(2,3,4)].
- Whole-blood aggregometry measures the increase in impedance across paired electrodes as platelets aggregate [(5,6)].
- Multiple electrode impedance aggregometry is a type of whole-blood aggregometry that uses multiple electrodes to measure platelet aggregation 6.
Clinical Applications
- Aggregometry is used to assess platelet function in patients taking antiplatelet medications, such as aspirin and clopidogrel [(2,3,4,5,6)].
- The test can help identify patients who are not responding adequately to antiplatelet therapy, which can increase the risk of cardiovascular events [(3,4)].
- Aggregometry can also be used to monitor the effectiveness of antiplatelet therapy and adjust treatment as needed [(2,3,5,6)].