A rotational intravascular ultrasound probe (100, 200, 300, 400, 500, 600) for insertion into a vasculature, the probe comprising: an elongate catheter (101, 201, 301, 401, 501, 601) having a flexible body (102, 202, 302, 402, 502, 602), an elongate transducer shaft (104, 204, 304, 404, 504, 604) disposed within the flexible body, the transducer shaft having a drive cable and a PMUT or CMUT transducer coupled to the drive cable at a distal end portion of the transducer shaft, and proximal connector (228, 328, 428, 528, 628) at or adjacent a proximal end portion of the flexible body; and an interface module (114, 214, 314, 414, 514, 614) configured to interface with the proximal connector of the elongate catheter; characterised in that the interface module includes: a spinning element (132, 232, 332, 432, 532, 632) comprising a connector (244, 344, 444, 544, 644) configured to be fixedly coupled to the proximal connector on the proximal portion of the transducer shaft, the spinning element having an electronic component coupled thereto such that when the spinning element is fixedly coupled to the proximal portion of the transducer shaft the electronic component is in electrical contact with the transducer; a stationary element (250, 350, 450, 550, 650) positioned adjacent to and spaced from the spinning element, wherein the stationary element is configured to pass signals to the spinning element and receive signals from the spinning element; and a motor coupled (236, 336, 436, 536, 636) to the spinning element for rotating the spinning element and the transducer shaft when the spinning element is fixedly coupled to the proximal portion of the transducer shaft; and wherein the spinning element includes a generator for generating power for the transducer. an elongate catheter (101, 201, 301, 401, 501, 601) having a flexible body (102, 202, 302, 402, 502, 602), an elongate transducer shaft (104, 204, 304, 404, 504, 604) disposed within the flexible body, the transducer shaft having a drive cable and a PMUT or CMUT transducer coupled to the drive cable at a distal end portion of the transducer shaft, and proximal connector (228, 328, 428, 528, 628) at or adjacent a proximal end portion of the flexible body; and an interface module (114, 214, 314, 414, 514, 614) configured to interface with the proximal connector of the elongate catheter; characterised in that the interface module includes: a spinning element (132, 232, 332, 432, 532, 632) comprising a connector (244, 344, 444, 544, 644) configured to be fixedly coupled to the proximal connector on the proximal portion of the transducer shaft, the spinning element having an electronic component coupled thereto such that when the spinning element is fixedly coupled to the proximal portion of the transducer shaft the electronic component is in electrical contact with the transducer; a stationary element (250, 350, 450, 550, 650) positioned adjacent to and spaced from the spinning element, wherein the stationary element is configured to pass signals to the spinning element and receive signals from the spinning element; and a motor coupled (236, 336, 436, 536, 636) to the spinning element for rotating the spinning element and the transducer shaft when the spinning element is fixedly coupled to the proximal portion of the transducer shaft; and wherein the spinning element includes a generator for generating power for the transducer. a spinning element (132, 232, 332, 432, 532, 632) comprising a connector (244, 344, 444, 544, 644) configured to be fixedly coupled to the proximal connector on the proximal portion of the transducer shaft, the spinning element having an electronic component coupled thereto such that when the spinning element is fixedly coupled to the proximal portion of the transducer shaft the electronic component is in electrical contact with the transducer; a stationary element (250, 350, 450, 550, 650) positioned adjacent to and spaced from the spinning element, wherein the stationary element is configured to pass signals to the spinning element and receive signals from the spinning element; and a motor coupled (236, 336, 436, 536, 636) to the spinning element for rotating the spinning element and the transducer shaft when the spinning element is fixedly coupled to the proximal portion of the transducer shaft; and wherein the spinning element includes a generator for generating power for the transducer.