A method for user-steered path planning for an image-guided endoscopic procedure, comprising: presenting, on a display, a 2D sectional image showing a region of interest from a CT scan; defining a control point on the 2D sectional image within a patient's body lumen responsive to a first user input, wherein the control point is a voxel in the 2D sectional image which corresponds to a point in a 3D image space located on the plane of the 2D sectional image; presenting a new image centered at the control point; adjusting a viewing angle by rotating the field of view about the control point responsive to a second user input to present a new image, which shows a longitudinal section of the body lumen, wherein the new image corresponds to a section of the 3D image space at the new viewing angle; identifying a second point on a planned path within the body lumen responsive to a third user input; extending a planned path connecting the control point and the second point; redefining the second point as a new control point; and repeating the presenting step, the adjusting step, the identifying step, the extending step, and the redefining step until the planned path reaches a procedure starting point within the patient's body, wherein the path is planned through a tree-shaped anatomic structure, wherein the control point and the second point are voxels on the displayed image and the step of extending a planned path comprises repeatedly performing a cost analysis to link a neighboring voxel of the displayed image to a last voxel on the planned path starting at the control point, wherein the cost analysis analyzes intensity attributes and geometric characteristics for each neighboring voxel to select a voxel to link on the planned path and a weight factor for each attribute, wherein the intensity attributes include functions of one or more of: light intensity for a neighboring voxel, the mean value of light intensity for a neighborhood of a neighboring voxel, the standard deviation of light intensity for a neighborhood of a neighboring voxel; and the geometric characteristics include the radius of a minimum circle that centers at a neighboring voxel and intersects a bronchial wall. presenting, on a display, a 2D sectional image showing a region of interest from a CT scan; defining a control point on the 2D sectional image within a patient's body lumen responsive to a first user input, wherein the control point is a voxel in the 2D sectional image which corresponds to a point in a 3D image space located on the plane of the 2D sectional image; presenting a new image centered at the control point; adjusting a viewing angle by rotating the field of view about the control point responsive to a second user input to present a new image, which shows a longitudinal section of the body lumen, wherein the new image corresponds to a section of the 3D image space at the new viewing angle; identifying a second point on a planned path within the body lumen responsive to a third user input; extending a planned path connecting the control point and the second point; redefining the second point as a new control point; and repeating the presenting step, the adjusting step, the identifying step, the extending step, and the redefining step until the planned path reaches a procedure starting point within the patient's body, wherein the path is planned through a tree-shaped anatomic structure, wherein the control point and the second point are voxels on the displayed image and the step of extending a planned path comprises repeatedly performing a cost analysis to link a neighboring voxel of the displayed image to a last voxel on the planned path starting at the control point, wherein the cost analysis analyzes intensity attributes and geometric characteristics for each neighboring voxel to select a voxel to link on the planned path and a weight factor for each attribute, wherein the intensity attributes include functions of one or more of: light intensity for a neighboring voxel, the mean value of light intensity for a neighborhood of a neighboring voxel, the standard deviation of light intensity for a neighborhood of a neighboring voxel; and the geometric characteristics include the radius of a minimum circle that centers at a neighboring voxel and intersects a bronchial wall.