Imatron Blood Flow Tutorial - Movies

Reference Slice

MPEG Movies of Pulmonary Blood Flow

High Spatial Resolution EBCT Data Set

The 40 slice Imatron Eletron Beam CT data set . These 3mm contiguous sections, gated to the cardiac cycle, gathered over 40sec with a 50 msec scan aperture, are used to evaluate anatomic detail. The information gathered from the high temporal resolution imaging can be maped into this data set to allow for correlation of structure and function.

High Temporal Resolution EBCT Data Set

The 80 slice high temporal resolution electron beam CT data set . The Slices are acquired in this sequence. 4 pairs of 8mm thick sections are acquired gated to the cardiac cycle such that ten time points are gathered at each slice level. With 4mm gaps between contiguous slice pairs, data spans 7.6cm of the apex to base extent of the lung. Imaging commences one heart beat before injection of contrast. Timing is then adjusted to the transit time through the lungs of each individual subject. Typically, we scan at each cardiac cycle for 5 cycles to asssure acquisition of the peak of the time intensity curve, and then scan every second or third heart beat for the next 5 time point acquisitions so as to acquire a sufficient amount of the tail of the curve. Contrast is injected into the right side (as close to the right ventricle as is possible (taking into consideration the balance between risk and benifit of the particular scan). Opacified blood is pumped through the pulmonary vascular bed by the right heart and on out to the left side of the heart. In this image sequence showing each slice level at the ten time points, we have subtracted the first imaged slice from each of the remaining time points to produce the time intensity image sequences representing blood flow through the lungs.

Rotating MIPs projections of the Canine Pulmonary Vasculature

The lungs have been highlighted by segmentation via a region growing algorithm along with some interactive editing and them multiplying the non-pulmonary regions (mediastinum, rib cage, and abdomen) A maximum intensity project is used to display the 3-D anatomy of the pulmonary vasculature. Data is stair-stepped in appearance because of the relatively thick slices (3mm) relative to the size of the dog (10-12kg). Improvements could be made by overlapping slices, but there is a trade-off between image improvement, scanning time, and x-ray exposure. These images were sufficient to evaluate the relationship between regional differences in pulmonary blood flow and the structure of the first 4-5 generations of the pulmonary arteries.

Last modified: Fri Jun 4 13:27:51 CDT