An intracorporeal-imaging head, is provided, which combines at least optical and radioactive-emission imaging, possibly also with high-resolution position tracking. The radioactive-emission-imaging probe has a wide-aperture, or coarse collimator, for high count-rate efficiency; nevertheless, the high-resolution position tracking ensures high resolution of the radioactive-emission image. Specifically, wide-aperture collimation-deconvolution algorithms are provided, for obtaining a high-efficiency, high resolution image of a radioactive-emission source, by scanning the radioactive-emission source with a probe of a wide-aperture collimator, and at the same time, monitoring the position of the radioactive-emission probe, at very fine time intervals, to obtain the equivalence of fine-aperture collimation. The blurring effect of the wide aperture is then corrected mathematically. The intracorporeal-imaging head may further include ultrasound and MRI imagers, as well as a surgical instrument, such as a biopsy needle, a knife, a cryosurgery device, a resection wire, a laser ablation device, an ultrasound ablation device, other devices for localized radiation ablations, devices for implanting brachytherapy seeds, and other minimally invasive devices. According to another embodiment, an intracorporeal-detecting head is provided, which combines at least optical and radioactive-emission detectors, for a nullYes or Nonull type detection, by the at least two modalities.