Posted: May 22nd, 2023

ECCA has a very low relaxivity rate

This causes a disadvantage in terms of the speed required to carry out image processing and the quality of image processing in radiology. The process of image acquisition is very slow. This implies the use of ECCA contributes to processing constraints (16). The limitation of ECCA is based on a limited acquisition window that ranges between one and three minutes. Best outcomes from ECCA are achieved only when peak arterial enhancement is present.

This means, lack of peak arterial enhancement results in a lack of CE MRA acquisition (15). The quality of CE MRA depends on the quality of vessel to background contrast. Image acquisition that is initiated pre or post-peak arterial enhancement results in images that cannot be interpreted satisfactorily. This presents a disadvantage of ECCA since it requires critical timing of the peak arterial enhancement to achieve the required vessel to background contrast (9).

ECCA has a disadvantage compared to IVCA based on the relaxivity rate. ECCA has a very low relaxivity rate (15). The ECCA is disadvantaged in terms of MRA imaging hardware which results in a decrease in the vessel to background contrast. This makes ECCA incapable of imaging small-caliber diseased vessels (4, 6, 9). Imaging of small caliber vessels requires the use of high spatial resolution which cannot be achieved through the use of ECCA. IVCA is therefore preferred because it enhances arteries and veins in either first pass or steady-state MRA (13, 16).

Research into binding control agents resulted in the modification of gadolinium-based contrast agents through the incorporation of binding functional groups that could interact with protein functional groups into the formation of Modified Paramagnetic gadolinium chelates (7, 9). This formed foundation for superparamagnetic derivatives that demonstrate superior outcomes to modified paramagnetic gadolinium chelates. Imaging approaches in radiology would rely on emerging first-pass MRA control agents that would exhibit ECCA properties and steady rate MRA that would demonstrate IVCA properties