Synopsis
Plan and communicate image-guided biopsy or drainage by matching the clinical question, lesion anatomy, guidance modality, specimen or source-control goal, procedural risk, consent and follow-up to the patient’s actual situation.
- Image-guided biopsy obtains cells or tissue for diagnosis and treatment planning; drainage samples or removes fluid and can provide source control, decompression or a bridge to surgery.
- The safest access route is chosen from current cross-sectional imaging, target characteristics, adjacent vessels and organs, patient position, respiratory motion and the material required by pathology or microbiology.
- Ultrasound gives real-time, radiation-free needle visualisation when an acoustic window exists; CT gives accurate planning for deep or small targets; fluoroscopy and MRI have selected roles.
Key red flags
New dyspnoea, hypoxia, tachycardia, pleuritic chest pain or cyanosis after thoracic biopsy requires immediate pneumothorax assessment and respiratory escalation.
Hypotension, falling haemoglobin, expanding swelling or severe abdominal or back pain after biopsy or drainage requires urgent haemorrhage assessment and senior procedural review.
Persistent or worsening sepsis, rigors, shock, peritonism or absent drain output requires urgent source-control review for blockage, displacement, organ injury or an undrained collection.
A fluid collection is clinically relevant because of sepsis, mass effect, pain or failure of medical treatment, and drainage could obtain cultures while relieving or controlling the source of infection. If physiology deteriorates, start urgent sepsis resuscitation and antimicrobial treatment while escalating for immediate source-control review.
No safe window, interposed bowel or vessel, uncorrected bleeding risk, inability to cooperate, unstable physiology or a target that will not yield the requested material may make percutaneous intervention inappropriate. Pause and escalate to senior IR and surgical planning rather than attempting an unsafe route.
Reasoning priorities
Define the target, viable component, collection anatomy, safe access window, adjacent structures, prior surgery and the modality best suited to guidance.
Imaging must be recent enough for the clinical situation and reviewed in the procedural plane. If the lesion has changed, ask for additional planning imaging rather than relying on an old report.
Worked reasoning
A patient has fever, abdominal pain and CT evidence of a postoperative pelvic collection with a potential percutaneous window.
- Assess physiology, antibiotics, cultures, renal function, allergy history, analgesia and bleeding or thrombotic risk; involve surgery and IR because drainage is one part of source-control planning.
- Review the current CT to choose position, route, catheter strategy and whether bowel, bladder, vessels or solid organs intervene. Explain aspiration, catheter drainage, possible repeat intervention and surgery if access fails.
- Under sterile technique and appropriate monitoring, use ultrasound or CT to access the collection, aspirate for microbiology, place and secure a catheter when ongoing drainage is required, and document output and specimens.
- Review fever, pain, inflammatory markers, drain output and imaging response. Flush, reposition or exchange only under the agreed protocol; remove the catheter when the collection and clinical course support removal, and verify that a persistent cavity or fistula has not been missed.