Biomedical subjects

Luc Bidaut

Publications and source records attributed to Luc Bidaut.

3 recordsLinked to original sources

PubMed2006

Dynamic ventilation imaging from four-dimensional computed tomography.

A novel method for dynamic ventilation imaging of the full respiratory cycle from four-dimensional computed tomography (4D CT) acquired without added contrast is presented. Three cases with 4D CT images obtained with respiratory gated acquisition for radiotherapy treatment planning were selected. Each of the 4D CT data sets was acquired during resting tidal breathing. A deformable image registration algorithm mapped each (voxel) corresponding tissue element across the 4D CT data set. From local average CT values, the change in fraction of air per voxel (i.e. local ventilation) was calculated. A 4D ventilation image set was calculated using pairs formed with the maximum expiration image volume, first the exhalation then the inhalation phases representing a complete breath cycle. A preliminary validation using manually determined lung volumes was performed. The calculated total ventilation was compared to the change in contoured lung volumes between the CT pairs (measured volume). A linear regression resulted in a slope of 1.01 and a correlation coefficient of 0.984 for the ventilation images. The spatial distribution of ventilation was found to be case specific and a 30% difference in mass-specific ventilation between the lower and upper lung halves was found. These images may be useful in radiotherapy planning.

Algorithms↗

PubMed2006

Molecular imaging reveals skeletal engraftment sites of transplanted bone marrow cells.

Molecular imaging holds great promise for the in vivo study of cell therapy. Our hypothesis was that multimodality molecular imaging can identify the initial skeletal engraftment sites post-bone marrow cell transplantation. Utilizing a standard mouse model of bone marrow (BM) transplantation, we introduced a combined bioluminescence (BLI) and positron emission tomography (PET) imaging reporter gene into mouse bone marrow cells. Bioluminescence imaging was used for monitoring serially the early in vivo BM cell engraftment/expansion every 24 h. Significant cell engraftment/expansion was noted by greatly increased bioluminescence about 1 week posttransplant. Then PET was applied to acquire three-dimensional images of the whole-body in vivo biodistribution of the transplanted cells. To localize cells in the skeleton, PET was followed by computed tomography (CT). Co-registration of PET and CT mapped the sites of BM engraftment. Multiple, discrete BM cell engraftment sites were observed. Taken together, this multimodality approach may be useful for further in vivo characterization of various therapeutic cell types.

Animals↗

PubMed2004

Advanced imaging including PET/CT for cardiothoracic surgery.

Medical imaging has always been essential for the diagnosis and management of many problems encountered in cardiothoracic surgical practice, from the assessment of cardiac function (e.g., by providing the location and extent of an infarct), to defining the extent of a malignancy via noninvasive imaging modalities to guide the choice of more invasive steps (e.g., biopsies or resections). Although most imaging still relies on standard radiological modalities such as computed tomography (CT), positron emission tomography (PET) has become more widely used in the US since its most recent clinical breakthrough. With the increasing availability of combined PET/CT units that deliver both anatomical and metabolic information in a single examination, PET imaging can potentially be used to a greater extent than what has been previously attainable. This review will provide an overview of recent advances in imaging that are likely to influence the direction of cardiothoracic surgery in the near future.

Heart Diseases↗