What is bolus tracking technique?
Bolus tracking is a technique to optimize timing of the imaging. A small bolus of radio-opaque contrast media is injected into a patient via a peripheral intravenous cannula.
What is test bolus in CT scan?
Test bolus. In this method, a small amount of contrast 10 mL (initial test bolus) is injected initially to detect the accurate time of the contrast reaching the pulmonary artery and calculate the delay time between contrast injection and the start of the scan.
What is bolus timing?
The bolus timing method allows the optimal monitoring phase and scan time to be determined and the repetitive radiation dose to be decreased. The ideal protocol setting for a monitoring scan with bolus timing depends on the HU value in the target vein (awareness of the HU value at the trigger threshold).
Does CTPA show heart?
CTPA allows assessment of not only the pulmonary arteries for embolism, but also of the bronchi, lung parenchyma, mediastinum and heart.
Why is CTPA done?
CT pulmonary angiogram (CTPA) is a medical diagnostic test that employs computed tomography (CT) angiography to obtain an image of the pulmonary arteries. Its main use is to diagnose pulmonary embolism (PE).
What is CARE bolus?
Care bolus is the most commonly used bolus tracking technique in contrast-enhanced magnetic resonance angiography. This technique uses a fast gradient refocused sequence with a special fourier transformation. Only the centre of the Fourier space is measured as quickly as possible.
What is a bolus MRI?
Bolus-tracking MRI involves the bolus injection of contrast agent, and the resultant concentration time course can be used to calculate perfusion by deconvolution analysis. However, most deconvolution methods do not provide a measure of precision.
What is difference between bolus and infusion?
The bolus achieves a very high peak which only lasts 5–6 hours. The infusion achieves steady levels after an initial delay. An infusion produces a steady level which can be varied and is exactly what is needed, for example during and after surgery.
What is the purpose of bolus infusion?
A bolus delivered directly to the veins through an intravenous drip allows a much faster delivery which quickly raises the concentration of the substance in the blood to an effective level. This is typically done at the beginning of a treatment or after a removal of medicine from blood (e.g. through dialysis).
How does bolus tracking work for data acquisition?
Bolus tracking allows for the initial injection of the entire contrast medium volume, whereas the start of the data acquisition is triggered based on automated detection of the contrast bolus arrival using preassigned trigger thresholds (eg, 100–120 HU) [5,16].
How is bolus tracking used in contrast media?
Precise timing of scan initiation during or after injection of contrast media may be achieved by using bolus tracking. Bolus tracking monitors the attenuation within a vessel or target organ on repeated axial sections.
Why are haste and PASL used for bolus tracking?
FAIR describes the particular PASL protocol used (see Fig. 12.3 ), while HASTE (half-Fourier single shot turbo spin-echo) is used for data acquisition. The latter was chosen due to its relative insensitivity to image distortions in regions of high magnetic susceptibility gradients, such as the temporal lobes.
What are the benefits of a CTPAT portal?
The Portal provides flexibility to adapt to future data requirements and administer multiple partnership programs, e.g., CTPAT and CTPAT Trade Compliance within a single site. Partner Benefits of Portal’s design include the following: Trade accounts participating in multiple partnership programs can be accessed via a single sign-on.