Fusion in medical imaging: theory, interests and industrial applications.

The accumulation of several data coming from medical images and signals, expert knowledge and databases is becoming very common for the study of a given pathology. The aggregation of all this information is mentally performed by a clinician, and generally allows for a better medical decision in clinical studies. We propose in this article a fusion method that models this aggregation process.

Iterative reconstruction methods for nonuniform attenuation distribution in SPECT.

Two iterative methods, a generalization of the Chang method and a projection precorrection, were investigated to determine whether the use of an attenuation map could improve nonuniform attenuation compensation. After a detailed description of the methods, results obtained with simulated and phantom data were compared. This study demonstrates that projection precorrection provides accurate quantification and good image quality as early as the precorrection step, whereas the generalized Chang method requires computation of one more iteration.

The value of pixel per pixel multiharmonic Fourier analysis to assess left ventricular function.

Left ventricular systolic and diastolic function can be assessed by peak ejection and filling rates and their time of occurrence. These parameters can be calculated using two different methods: from the global left ventricular time-activity curve analysed with a four harmonic Fourier fit and from each pixel time-activity curve analysed with two and three harmonics (the values being averaged over the left ventricular region of interest). In both cases, values were normalized for heart rate and end diastolic counts.

Improved detection of anterior left ventricular aneurysm with multiharmonic fourier analysis.

Single and multiharmonic Fourier analysis of LAO 30-45 degrees gated blood-pool studies were performed in a selected group of 30 patients with a left ventricular anterior aneurysm proven by contrast angiography. The sensitivity of the first harmonic phase image for the diagnosis of ventricular aneurysm was 80%. The clear phase shift (greater than 110 degrees) between the normal and the aneurysmal areas was missing in six patients.