Modified chest leads

MCLj (modified chest lead) and MCL (similar to the unipolar leads Vj and Vg of the 12-lead ECG). 

Pulsation of the aorta causes artifacts, especially in the aortic root and ascending aorta. ECG-triggered data acquisition helps to significantly reduce these artifacts and therefore plays an important role in the examination of unclear chest pain or thoracic aortic dissection (Fig. 23.1). Furthermore, this technique enables the evaluation of coronary arteries and can replace invasive clinical diagnostics in some cases. Flowever, detailed protocols of the thoracic aorta are normally based on protocols of coronary artery CT. Due to their specifications, they lead to longer acquisition times than those of standard protocols and do not properly visualize the abdominal aorta. This can be overcome by an ECG-gated acquisition of the thoracic aorta and a change to the standard protocol for the abdominal aorta. In order to achieve a sufficient contrast in the abdominal aorta, the time delay to modify the examination protocol should be minimized (Fig. 23.2). 

---