An ultrasound imaging catheter, comprising: an ultrasound transducer array provided at a distal end of the ultrasound imaging catheter and adapted to transmit and receive ultrasound signals, wherein the ultrasound transducer array comprises a plurality of ultrasound transducer elements; a local memory provided at the distal end of the ultrasound imaging catheter adapted to store a plurality of activation patterns, wherein each activation pattern corresponds to a number of transducer elements of the plurality of transducer elements to be activated and a number of transducer elements of the plurality of transducer elements to be deactivated; a control unit provided at the distal end of the ultrasound imaging catheter adapted to: access the local memory; select any one of the plurality of activation patterns; generate a control signal to activate or deactivate the plurality of transducer elements of the transducer array according to the selected activation pattern during an imaging phase of the ultrasound imaging catheter, the imaging phase comprising a transmit period and a receive period; wherein the ultrasound imaging catheter further comprises: a plurality of registers, each register comprising a plurality of bits, wherein each bit is associated with an ultrasound transducer element of the plurality of ultrasound transducer elements; a local oscillator in communication with the plurality of registers and adapted to receive the control signal generated by the control unit and manipulate the plurality of bits in the plurality of registers to activate and/or deactivate the plurality of transducer elements of the transducer array according to the selected activation pattern; characterized in at least one of: the local oscillator being adapted to operate outside of the imaging phase of the ultrasound imaging catheter; the local oscillator being adapted to operate at a frequency that is greater than a bandwidth of the plurality of ultrasound transducer elements; the local oscillator being adapted to generate a square wave having a given duty cycle, wherein the given duty cycle is such that components of the local oscillator's frequency spectrum are outside the bandwidth of the plurality of ultrasound transducer elements. an ultrasound transducer array provided at a distal end of the ultrasound imaging catheter and adapted to transmit and receive ultrasound signals, wherein the ultrasound transducer array comprises a plurality of ultrasound transducer elements; a local memory provided at the distal end of the ultrasound imaging catheter adapted to store a plurality of activation patterns, wherein each activation pattern corresponds to a number of transducer elements of the plurality of transducer elements to be activated and a number of transducer elements of the plurality of transducer elements to be deactivated; a control unit provided at the distal end of the ultrasound imaging catheter adapted to: access the local memory; select any one of the plurality of activation patterns; generate a control signal to activate or deactivate the plurality of transducer elements of the transducer array according to the selected activation pattern during an imaging phase of the ultrasound imaging catheter, the imaging phase comprising a transmit period and a receive period; access the local memory; select any one of the plurality of activation patterns; generate a control signal to activate or deactivate the plurality of transducer elements of the transducer array according to the selected activation pattern during an imaging phase of the ultrasound imaging catheter, the imaging phase comprising a transmit period and a receive period; a plurality of registers, each register comprising a plurality of bits, wherein each bit is associated with an ultrasound transducer element of the plurality of ultrasound transducer elements; a local oscillator in communication with the plurality of registers and adapted to receive the control signal generated by the control unit and manipulate the plurality of bits in the plurality of registers to activate and/or deactivate the plurality of transducer elements of the transducer array according to the selected activation pattern; characterized in at least one of: the local oscillator being adapted to operate outside of the imaging phase of the ultrasound imaging catheter; the local oscillator being adapted to operate at a frequency that is greater than a bandwidth of the plurality of ultrasound transducer elements; the local oscillator being adapted to generate a square wave having a given duty cycle, wherein the given duty cycle is such that components of the local oscillator's frequency spectrum are outside the bandwidth of the plurality of ultrasound transducer elements. the local oscillator being adapted to operate outside of the imaging phase of the ultrasound imaging catheter; the local oscillator being adapted to operate at a frequency that is greater than a bandwidth of the plurality of ultrasound transducer elements; the local oscillator being adapted to generate a square wave having a given duty cycle, wherein the given duty cycle is such that components of the local oscillator's frequency spectrum are outside the bandwidth of the plurality of ultrasound transducer elements.