Fig. 4.

57-year-old man presented with atypical chest pain.

Depth (A) and length (B) of tunneled segment (arrows) of left anterior descending coronary artery were 4.4 mm and 39.3 mm, respectively. Systolic (C) and diastolic (D) curved multiplanar reformation images of tunneled left anterior descending coronary artery segment show that lumen of tunneled segment is compressed by myocardial contraction in systolic phase (C), but had normal diameter in diastolic phase (D). This phenomenon is known as 'milking effect'.