An apparatus and related methods for ultrasonically scanning a tissue volume are described, the apparatus being particularly advantageous in the context of freehand ultrasound assisted biopsy of the breast although readily applied to non-biopsy contexts and other body parts. The apparatus comprises a casing configured and dimensioned for single-handed manipulation relative to a surface of the tissue, and a texturably couplant-porous material sheet extending across an opening of the casing. The texturably couplant-porous material sheet has an outer side and an inner side relative to the casing, the outer side for compressively contacting the tissue surface. The apparatus further comprises an ultrasound transducer positioned against the inner side of the texturably couplant-porous material sheet and being mechanically translatable thereacross for volumetrically scanning the tissue volume therethrough.