3D-reconstruction of coronary arteries in view of flow measurement

Abstract

An angiographic method for measurement of absolute coronary blood flow in patients was developed. It is based on 3D-reconstruction of the left or right coronary tree from digitized biplane coronary cineangiograms. The apparatus is presently composed of a 35 mm cinefilm projector with a video camera and a 512 x 512 x 8 bits image array processor controlled by a VAX-11/750 computer. First, the parameters of the two angiographic projections are determined in form of two 4 x 3 matrices from a pair of cineframes showing a 4 cm cube bearing markers. The cube is filmed after the coronary injection, with unchanged geometric configuration. The coronary arteries of interest are then 3D-reconstructed from a pair of cineframes showing them fully opacified. This allows to compute the intravascular volumes needed for flow determination. In vitro experiments showed that the obtained volume are reasonably accurate. For the measurement of coronary flow, the concentration of contrast medium along the involved arteries is computed (in arbitrary units) from two cineframes taken one (or two) cardiac cycle after onset of the injection. This yields a 'concentration-distance' curve per artery. The volume of fluid (contrast medium mixed with blood) which flows into the arteries during this (or these two) cardiac cycle is determined by applying a concentration threshold to the obtained concentration-distance curves. Measurements performed on a constant flow model were satisfying. Preliminary measurements in 12 patients showed that flow values obtained angiographically into the left anterior descending coronary artery correlate well with the values measured simultaneously by thermodilution in the great cardiac vein (Qangio = 0.83 x Qthermo + 16.1 ml, r = 0.87, n = 29).

Three-Dimensional Reconstruction of Foot Based on Marching Cubes

“…By connecting the patches from all cubes on the iso-surface boundary, we get a surface representation. Because of its merits of simple, easy to achieve, it has been widely used, is considered as one of the most popular algorithms for display [6][7][8][9][10].…”

Neue Entwicklungen in der Diagnostik der koronaren Herzerkrankung ¶– 3D Fusionsbild

“…Interaktive Techniken für eine 3D Rekonstruktion von Koronararterien bieten den Vorteil, mögliche Fehler zu vermeiden, welche bei einer gänzlich automatischen Segmentierung der Koronararterien vorkommen können (7-8, 28, 31, 35). Eine wesentliche Limitierung der interaktiven 3D Rekonstruktion des Koronarbaumes ist jedoch ein relativer Zeitaufwand durch die Eingabe von korrespondierenden Punkten und Linien im Verlauf der Koronargefäße (11,17,32,39). Obwohl eine Automatisierung des Segmentationsprozesses die Rekonstruktion beschleunigen, besser reproduzieren und objektivieren kann, liefert sie nicht notwendigerweise genauere Ergebnisse (20).…”

Towards measurement of coronary blood flow in patients and its alteration by interventions

“…Guggenheim et al and Dorsaz et al from our group later studied the progression of contrast medium during a single heart beat in triggering biplane X-ray sources by the QRS-complex. A threedimensional reconstruction of the coronary tree using a projection matrix was developed [23][24][25] , and automated densitometric evaluation of the progression of the bolus allowed measurement of flow in the different branches of the left and right coronary artery tree [26] .…”