PubMed · 5946303
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M Stahlman. 1966. Perinatal circulation.. https://doi.org/10.1016/s0031-3955(16)31881-8
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PURPOSE: To evaluate image quality, vessel conspicuity, and signal-to-noise ratio (S/N) of four two-dimensional magnetic resonance (MR) phase-contrast techniques: cine phase-contrast with respiratory compensation (CPC-R), cine phase-contrast without respiratory compensation (CPC), phase-contrast with two signals acquired (PC-2), and phase-contrast with eight signals acquired (PC-8). MATERIALS AND METHODS: MR angiographic images of the portal vein were obtained in 14 patients. RESULTS: Overall image quality was rated excellent in 10 of 14 patients (CPC-R), in one of 14 patients (CPC), in none of 14 patients (PC-2), and in one of 14 patients (PC-8). Views of 10 upper abdominal vessels were evaluated with each technique. The mean (+/- standard deviation) number of well-imaged vessels was 6 +/- 2 (CPC-R), 3 +/- 2 (CPC), 2 +/- 2 (PC-2), and 3 +/- 2 (PC-8). CPC-R images were significantly better in overall image quality and number of vessels seen (P < .01). Mean S/Ns were 10.8 +/- 3.4 (CPC-R), 6.8 +/- 2.7 (CPC), 4.5 +/- 1.7 (PC-2), and 6.4 +/- 2.1 (PC-8). S/N with CPC-R was significantly greater than with CPC, PC-2, or PC-8. CONCLUSION: CPC-R provided consistently higher quality angiographic images than were obtained with the other sequences studied.
Using a biplane multidirectional isocentric X-ray system, a computer-aided simulation procedure was developed to calculate the 3D structure of the coronary arteries. The algorithm uses the geometry of the biplane X-ray system and the alignments of corresponding points of the coronary arteries in two X-ray images acquired under different viewing angles. The identification of the corresponding points is greatly simplified by the calculation and display of the intersection lines of the confocal plane with the image intensifier entrances on the computer monitor. To minimize the total number of necessary corresponding points we used Bézier curves to match the courses of the coronary segments between neighboring corresponding points. The projection of the calculated 3D structure was found to be in very good agreement with the 2D course of the coronary arteries in the angiograms. The 3D structure can be viewed on the computer screen under any desired simulated projection angle within the geometrical limitation of the X-ray gantries. The user can select views on the computer monitor with orthogonal projection angles and minimal overlapping problems caused by under- and overlying structures. The method was applied in 10 cases of elective angioplasty. Previously taken diagnostic angiograms were used to reconstruct the arterial structure and to select favorable views for the forthcoming intervention.
A new computerized method for analyzing biplane coronary arteriograms was proposed. The method extracted the vessels in an image, detected branching points, and identified vessel segments according to their anatomical names. The method was applied to a pair of orthogonal projection images acquired in the right anterior oblique and left anterior oblique views. It recognized the corresponding vessel segments in the images and labeled them correctly by their anatomical names. For diameter measurement, a combined first and second derivative filter process was applied to the images along the skeleton lines of the extracted vessel segments. We also designed a method of representation in which vessel diameters measured in the two projection images could be displayed in a single image.