Operational Standards For Image-Guided Chiba Needle Biopsy

https://radiopaedia.org/articles/chiba-needle

Technical Key Points and Pitfall Avoidance for Ultrasound and CT Dual-Guidance Modes

The clinical efficacy of the Chiba needle highly depends on the quality of image guidance. Currently, the mainstream methods are ultrasound (US) guidance and CT guidance, each with its own strengths.

Ultrasound Guidance (US-FNA)

• Applicable Sites:​ Thyroid, breast, superficial lymph nodes, liver, kidney, prostate, and some pancreatic body lesions.
• Advantages:​ Real-time dynamic visualization of needle trajectory, no radiation, low cost, ability to avoid blood vessels using color Doppler.
• Operational Key Points:​ A high-frequency linear array probe (7.5–12 MHz) displays the lesion and surrounding vessels. Select a Chiba needle with scale markings and an Echo-tip (ultrasound reflective ring), and use an in-plane approach to display the entire needle body. Align the needle angle with the probe section, slowly advance to the center of the lesion, attach a 2–5 mL syringe to maintain mild negative pressure, thrust and withdraw 2–3 times, then release negative pressure and withdraw the needle for smear preparation.
• Common Mistakes:​ Mistaking the needle tip as being in place when it is only displayed in the subcutaneous layer; excessive negative pressure causing cell rupture or blood dilution; accidentally puncturing the trachea dorsal to the isthmus during thyroid puncture.

CT Guidance

• Applicable Sites:​ Pulmonary nodules, mediastinal lesions, deep retroperitoneal lymph nodes, pancreatic uncinate process, bone tumors.
• Advantages:​ Good resolution of gas/fat/bone, precise distance measurement, suitable for lesions <1 cm or deep-seated lesions.
• Operational Key Points:​ First perform a plain scan to locate the lesion, mark the skin entry point, calculate the insertion depth and angle (common formula: skin-to-lesion distance ÷ cosθ). Administer local anesthesia to the capsule, instruct the patient to hold their breath (critical for lung/liver puncture), quickly break through the pleura/liver capsule, then slowly advance to the lesion. Confirm needle tip position with CT, then aspirate. Typically use a 22G Chiba needle; if necessary, first place a coaxial positioning needle and then sample through the sheath to reduce lung tissue damage.
• Complication Prevention:​ After lung puncture, keep the patient supine for 2–4 hours and review a chest X-ray to rule out delayed pneumothorax; avoid puncturing directly through the gallbladder/large bile duct during liver puncture.

Regardless of the guidance method, dual verification of the operator's tactile sense and imaging confirmation is the iron rule to prevent accidental puncture of blood vessels and hollow organs. For atypical lesions, it is recommended to sample from multiple directions or combine FNA with cutting needle to improve positivity rates.