Patent Document ID: 9684981
Application ID: 14811820
Patent Status: 1

Claim One:
1. A method for reconstructing a cardiac image, comprising: collecting projection data and recording electrocardiogram data when computed tomographic scanning is performed on a patient; selecting, based on the electrocardiogram data, first projection data related to each cardiac pixel with a same phase from the projection data, and then obtaining a cardiac image by reconstructing an image of the related cardiac pixel based on the first projection data; determining a reconstruction phase of each reconstruction pixel in a first reconstruction region based on the electrocardiogram data, wherein the first reconstruction region is an image region selected along the patient's head-to-foot direction from the cardiac image; and selecting, based on the reconstruction phase of each reconstruction pixel, second projection data related to the reconstruction pixel with the reconstruction phase from the projection data, and then reconstructing an image of the reconstruction pixel based on the second projection data; wherein the determining a reconstruction phase of each reconstruction pixel in a first reconstruction region based on the electrocardiogram data, comprises: acquiring intervals of the first reconstruction region, wherein the intervals comprise a first number of first reconstruction intervals not next to each other, and a second number of first transition intervals between the adjacent first reconstruction intervals: acquiring reconstruction phases of the first reconstruction intervals determined based on the electrocardiogram data; determining, based on the reconstruction phases of the first reconstruction intervals and a reconstruction position of the first transition interval, a reconstruction phase of each reconstruction pixel in the first transition interval; and wherein in the case that the first number of the first reconstruction intervals are divided along a direction from the head to the feet of the patient, the reconstruction phase I V1W1X1 of each reconstruction pixel in the first transition interval is determined by using the following interpolation formula: I V ⁢ ⁢ 1 ⁢ W ⁢ ⁢ 1 ⁢ X ⁢ ⁢ 1 = V ⁢ ⁢ 1 + ( Lx ⁢ ⁢ 1 - Lv ⁢ ⁢ 1 ) × V ⁢ ⁢ 1 - W ⁢ ⁢ 1 Lv ⁢ ⁢ 1 - Lw ⁢ ⁢ 1 , wherein V1 is a reconstruction phase of a first reconstruction interval that is next to the first transition interval and in the direction towards the head of the patient; W1 is a reconstruction phase of a first reconstruction interval that is next to the first transition interval and in the direction towards the foot of the patient; Lv1 is a critical position, closer to the head of the patient, of the first transition interval containing a current reconstruction pixel; Lw1 is a critical position, closer to the feet of the patient, of the first transition interval containing the current reconstruction pixel; and Lx1 is a reconstruction position of the current reconstruction pixel.