Image-Guided Biopsy

Technique Fundamentals

• Coaxial technique: Introducer needle placed to lesion margin, then core biopsy or FNA needle advanced through it. Allows multiple passes without re-traversing tissue and reduces tumor seeding risk.
• Core needle biopsy (CNB) vs Fine-needle aspiration (FNA): CNB uses cutting needle (typically 18–20G) for histologic tissue cores. FNA uses thin needle (20–25G) for cytology. CNB preferred for most solid organ lesions; FNA for thyroid, lymph nodes, and when core is high-risk.
• Number of passes: Typically 3–5 cores for adequate tissue. On-site cytopathology (ROSE) when available increases diagnostic yield and reduces non-diagnostic rates.
• Guidance modality: CT for deep lesions, retroperitoneal targets, and lesions near critical structures. US for superficial, well-visualized lesions (liver, kidney, thyroid). Fluoroscopy for bone lesions with CT correlation.

Planning & Safety

• Review cross-sectional imaging to plan shortest, safest trajectory avoiding bowel, major vessels, pleura, and fissures
• For lung biopsy: position biopsy side DOWN post-procedure to tamponade the puncture site
• Specimen handling: Formalin for histology, saline for culture, CytoLyt/ThinPrep for cytology, fresh tissue for flow cytometry and molecular testing
• Track/coax embolization (gel foam pledget) may reduce pneumothorax rates in lung biopsy
• The ideal level has a vertebral body or solid organ as the “backstop” to prevent over-advancement

General Contraindications

• Absolute: Uncorrectable coagulopathy, no safe access window, uncooperative patient
• Relative: Anticoagulation (hold per SIR guidelines), severe emphysema (lung — high PTX risk), hydatid cyst (anaphylaxis risk), suspected vascular lesion (hemangioma, AVM), interposed bowel

SIR Bleeding Risk by Target

Immediate

• Bleeding / hematoma — most common across all targets; usually self-limited
• Pneumothorax (lung biopsy) — 15–25% incidence, ~5% require chest tube
• Pain at biopsy site
• Vasovagal reaction

Delayed

• Tumor seeding along needle tract — rare, risk reduced with coaxial technique
• Infection / abscess — rare with sterile technique
• Non-diagnostic result — may require repeat biopsy or surgical excision
• Organ-specific: hemothorax (lung), bile leak (liver), hematuria (kidney), fracture (bone)

Key Guidelines

• ACR Practice Parameter for Image-Guided Percutaneous Needle Biopsy (2021)
• SIR quality improvement guidelines for image-guided biopsies

Primary References

• Gupta S, Wallace MJ, Cardella JF, et al. Quality improvement guidelines for percutaneous needle biopsy. J Vasc Interv Radiol. 2010;21(7):969–975.
• Monfardini L, Preda L, Aurilio G, et al. CT-guided biopsy in cancer patients: review of 296 cases. Eur Radiol. 2011;21(11):2399–2407.
• Fischbach F, Knollmann F, Griesser V, et al. Detection of pulmonary nodules by multislice computed tomography. Eur Radiol. 2003;13(10):2378–2383.