Cytopathology
Ultrasound guided fine needle aspiration (USFNA)
Ultrasound guided needle placement

Author: Joe D. Jakowski, M.D., Susan Meanor, R.D.M.S., R.T. (see Authors page)

Revised: 6 February 2018, last major update March 2013

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Technique [title] of ultrasound guided needle placement

Cite this page: Jakowski, J. D.; Meanor, S. Ultrasound guided needle placement. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cytopathologyusfnaplacement.html. Accessed June 20th, 2018.
Definition / general
  • Being proficient in traditional palpation guided FNA (PGFNA) technique makes transition to USFNA easier
  • Acquiring proper US scanning and operation skills to produce a good quality US image is necessary
  • Documentation and description of US target and US needle placement images will also need to be obtained for medical record and billing purposes (see Documentation and Billing / CPT Coding)
Key steps to performing an USFNA
  1. Obtain proper patient and US machine positioning, adequate room lighting, and all necessary equipment
  2. "Find" and confirm target of interest for FNA using the US transducer (can use a surgical ink pen to make marks on skin if needed)
  3. Plan the best needle approach to the target using information from the US images (e.g. depth and relation to surroundings structures such as bones or large vessels)
  4. Cleanse the skin with antiseptic (70% isopropyl alcohol wipes, providone iodine, chlorhexidine) at site of needle entry
  5. Recheck for proper orientation of US transducer with respect to US display screen and patient
  6. Place needle under ultrasound guidance using one of two approaches defined by orientation of needle with respect to transducer US beam: parallel technique or perpendicular technique
Parallel technique
  • Also call azimuthal or longitudinal approach
  • Has advantage of being able to see entire needle trajectory during biopsy
  • Ideal technique to track needle tip at all times and to make sure it is within target, and to avoid entering surrounding structures
  • Main disadvantage is that it is technically challenging to line up the needle and keep it within the very thin US beam
  • Often penetrates more tissue using this approach
Perpendicular technique
  • Also called transverse approach
  • Technically less difficult because needle is passed through large section of US beam at 90 degrees
  • Needle penetrates less tissue during biopsy
  • Disadvantage is that only a cross section of the needle tip (and shaft) will be visualized at any one time during the biopsy
  • Cross section of needle will appear as hyperechoic "dot" within the target
  • Having the bevel of the needle pointing up during the biopsy may help make the needle tip visualization easier as the bevel will be more reflective and therefore more hyperechoic
  • Using the perpendicular approach:
    • You can only be sure you are sampling the target if the needle tip is seen within the target during the biopsy
    • The mere presence of the needle shaft in cross section within the target does not necessarily indicate you are sampling the target
Clinical images

Images hosted on PathOut server:
Missing Image

Perpendicular technique

Missing Image

Parallel technique