The patient's body habitus did not permit ultrasound guided biopsy.
The steps for CT guided renal biopsy: skin surface markers to choose site, following by infiltration needle and co-axial needle position prior to biopsy.
1. Local anaesthetic infiltration needle - to check position and aid angulation planning for co-axial needle.
2. Co-axial needle 'parked' in the ideal position prior to a 2cm biopsy core acquisition.
3. Bone windows allow for more accurate assessment of needle tip position, as artifact from needle reduced.