ABSTRACT
This work presents a system for the reconstruction of cross-sections with arbitrary orientations derived from three-dimensional (3D) echographic scanners. The interest for this powerful diagnostic tool has prompted us to develop a low-cost processing board that inserts easily into a stand-alone echograph. The proposed system is able to reconstruct high-resolution cross-sections at one frame per second with a time lag of about 60 s due the 3D acquisition process. The board, based on three pipelined DSP devices, has been designed to process volumetric data collected with a commercial echograph by means a rotating probe synchronized with the ECG signal. The resolution of the reconstruction algorithm implemented on the processing unit has been evaluated both with synthetic 3D data and with experimental data from a phantom.
Subject(s)
Echocardiography, Three-Dimensional/methods , Echocardiography/methods , Image Processing, Computer-Assisted/methods , Animals , Humans , Models, Theoretical , Phantoms, ImagingABSTRACT
Injection into mice of the anthracycline cytotoxic derivative Doxorubicin (DXR) covalently bound to bovine serum albumin (BSA) was associated with antigen-specific depression of the primary (but not of the secondary) antibody reaction to the carrier, whereas DXR and BSA injected in the form of a mixture caused no such effect. Tetanus toxoid completely prevented the carrier-specific inhibiting effect when administered at the same time as, but not three days before or after, injection of the DXR-BSA conjugate. Possible mechanisms of the antigen-specific immunodepression and its prevention by unrelated antigen are discussed.
Subject(s)
Antibody Formation/drug effects , Doxorubicin/pharmacology , Immunosuppressive Agents , Serum Albumin, Bovine/pharmacology , Animals , Antigens , Doxorubicin/immunology , Female , Macrophage Activation/drug effects , Mice , Mice, Inbred BALB C , Serum Albumin, Bovine/immunology , Tetanus Toxoid/immunologyABSTRACT
Quantitative two-dimensional echocardiography has been adversely affected by a tendency for underestimation of cross-sectional areas of cardiac chambers, a difficulty that might be ameliorated by recent advances in imaging technology. To determine if this were so, we measured echocardiographic cross-sectional areas of 25 formalin-fixed animal left ventricular (LV) sections in vitro using conventional 13 mm and 15 mm diameter fixed-focused single element transducers, and a 15 mm diameter dynamically focused annular array transducer at 3 different distances between myocardial slice and transducer (2 cm, 6 cm and 10 cm) and compared the 2-dimensional echocardiographic areas to the corresponding anatomic cross-sectional areas of the same hearts. LV total and cavity area were measured by computer assisted planimetry of videotaped echo images, performed blinded to the transducer used, and photographed anatomic slices; LV myocardial area was derived by subtraction. Comparison of two-dimensional echocardiographic total, myocardial, and cavity areas with corresponding anatomic measurements showed excellent correlation for each transducer at all depths (r = 0.97 to 0.98 for total area; r = 0.98 to 0.99 for cavity area; r = 0.93 to 0.97 for myocardial area). For total and myocardial cross-sectional areas, the slope of the relation between echographic and anatomic areas did not differ significantly from unity, but for LV cavity area this was achieved only by the dynamically focused transducer. In contrast, the conventional 13 mm transducer significantly underestimated larger LV cavity areas in both the near and middle fields (slopes = 0.90 and 0.91, respectively) and the 15 mm transducer yielded slopes from 0.86 to 0.91 in all fields.(ABSTRACT TRUNCATED AT 250 WORDS)
