- Probes can be characterized according to their:
- Shape
- Arrangement of the piezoelectric crystals
- Frequency range
- Footprint
- In general they are classified as:
Type
Description
Uses
Examples
Linear-Array
- Crystals arranged in a linear fashion
- Flat rectangular footprint which produces a rectangular image
- Generally of high frequency (5-10 MHz) providing good resolution for shallow structures
- A "hockey stick" probe is a linear array probe with a small footprint for use in paediatrics or smaller anatomical areas
- Vascular access
- Superficial nerve blocks (supraclavicular and axillary brachial plexus, forearm, femoral etc.)
- Musculoskeletal imaging
- Pleural imaging
Curvilinear (Convex) Array
- Crystals arranged alongside each other across a curved face
- Produce a sector shaped image with a curved top and bottom
- Generally of lower frequencies (2–5 MHz), allowing for better imaging of deeper structures
- Abdominal and pelvic imaging
- Lung Imaging
- Deep nerve blocks (sciatic, infraclavicular brachial plexus etc.)
Phased Array
- Crystals arranged in a very small cluster
- Has a flat footprint which produces a pie-shaped image
- Generally of lower-frequency (2–8 MHz) allowing imaging of deeper structures
- Small footprint makes it useful for cardiac imaging between ribs
- Echocardiography
Endocavity
- Specialist probes with long handles to scan inside body cavities
- Common examples include: vaginal, anorectal, laparoscopic and oesophageal probes
- Internal imaging (transvaginal, transrectal etc.)