An ultrasonic diagnostic imaging system for the qualitative or quantitative analysis of tissue perfusion comprising: an array transducer adapted to transmit and receive scanlines over a volumetric region containing tissue which may have a perfusion defect; a beamformer (36, 38), coupled to the array transducer, said beamformer being adapted to produce image data of a plurality of elevationally distinct slices (12-18; 22-24; S 1 -S 4) of the volumetric region, said slices being parallel to each other; a slice memory, coupled to the beamformer (36, 38), said memory being configured to store slice image data; a combiner, coupled to the slice memory, said combiner being arranged to combine slice image data in the elevation direction to form an elevationally combined slice image which can be displayed as a planar display of a slice with characteristics of multiple elevationally offset individual slices; and a display; wherein: the combiner is further arranged to apply a weighting to the slice image data in the elevation direction, wherein the weighting is based on a distance from a central slice, with data from the central slice weighted more greatly than the data of neighboring slices; the array transducer is arranged to transmit beams, each of which insonifies a plurality of receive line locations of multiple of the plurality of elevationally distinct slices, and arranged to receive echoes from the plurality of receive line locations simultaneously, the system further comprises a perfusion detector arranged to operate on the combined slice image data to qualitatively depict perfusion by the concentration of microbubbles in tissue and to produce a quantified perfusion parameter for a region of tissue, wherein the display is responsive to the perfusion detector for displaying at least one of the combined slice image with perfusion depicted by color or brightness, or a quantified perfusion parameter for a region of tissue. an array transducer adapted to transmit and receive scanlines over a volumetric region containing tissue which may have a perfusion defect; a beamformer (36, 38), coupled to the array transducer, said beamformer being adapted to produce image data of a plurality of elevationally distinct slices (12-18; 22-24; S 1 -S 4) of the volumetric region, said slices being parallel to each other; a slice memory, coupled to the beamformer (36, 38), said memory being configured to store slice image data; a combiner, coupled to the slice memory, said combiner being arranged to combine slice image data in the elevation direction to form an elevationally combined slice image which can be displayed as a planar display of a slice with characteristics of multiple elevationally offset individual slices; and a display; wherein: the combiner is further arranged to apply a weighting to the slice image data in the elevation direction, wherein the weighting is based on a distance from a central slice, with data from the central slice weighted more greatly than the data of neighboring slices; the array transducer is arranged to transmit beams, each of which insonifies a plurality of receive line locations of multiple of the plurality of elevationally distinct slices, and arranged to receive echoes from the plurality of receive line locations simultaneously, the system further comprises a perfusion detector arranged to operate on the combined slice image data to qualitatively depict perfusion by the concentration of microbubbles in tissue and to produce a quantified perfusion parameter for a region of tissue, wherein the display is responsive to the perfusion detector for displaying at least one of the combined slice image with perfusion depicted by color or brightness, or a quantified perfusion parameter for a region of tissue. the combiner is further arranged to apply a weighting to the slice image data in the elevation direction, wherein the weighting is based on a distance from a central slice, with data from the central slice weighted more greatly than the data of neighboring slices; the array transducer is arranged to transmit beams, each of which insonifies a plurality of receive line locations of multiple of the plurality of elevationally distinct slices, and arranged to receive echoes from the plurality of receive line locations simultaneously, the system further comprises a perfusion detector arranged to operate on the combined slice image data to qualitatively depict perfusion by the concentration of microbubbles in tissue and to produce a quantified perfusion parameter for a region of tissue, wherein the display is responsive to the perfusion detector for displaying at least one of the combined slice image with perfusion depicted by color or brightness, or a quantified perfusion parameter for a region of tissue.