A new, original and ornamental design for a portable medical ultrasonic imaging instrument. The intended use of the article in which the design is embodied is a medical ultrasonic diagnostic imaging system used to image the interior of the body by the processing of ultrasonic signals.

FIG. 1 is a forward perspective view of a first embodiment of a medical ultrasonic imaging instrument of the present invention.

FIG. 2 is a front view of the medical ultrasonic imaging instrument of FIG. 1.

FIG. 3 is a left side view of the medical ultrasonic imaging instrument of FIG. 1.

FIG. 4 is a right side view of the medical ultrasonic imaging instrument of FIG. 1.

FIG. 5 is a rear view of the medical ultrasonic imaging instrument of FIG. 1.

FIG. 6 is a top view of the medical ultrasonic imaging instrument of FIG. 1.

FIG. 7 is a forward perspective view of a second embodiment of a medical ultrasonic imaging instrument of the present invention.

FIG. 8 is a front view of the medical ultrasonic imaging instrument of FIG. 7.

FIG. 9 is a rear view of the medical ultrasonic imaging instrument of FIG. 1.

FIG. 10 is a left side view of the medical ultrasonic imaging instrument of FIG. 7.

FIG. 11 is a right side view of the medical ultrasonic imaging instrument of FIG. 7; and,

FIG. 12 is a top view of the medical ultrasonic imaging instrument of FIG. 7.