GC014 How Can Interventional Radiology Help Patient Management
Interventional radiology uses image-guided, minimally invasive procedures—such as angiography, embolization, drainage, biopsy, and stenting—to diagnose and treat a wide range of conditions, thereby reducing surgical morbidity and improving patient management.
How Can Interventional Radiology Help Patient Management
This GC lecture by Dr. Vince Lau (Honorary Clinical Associate Professor, HKU; Consultant Radiologist, QMH) provides a comprehensive overview of Interventional Radiology (IR) — a specialty that sits at the intersection of diagnostic imaging and minimally invasive therapy. The lecture is structured around a "week in the IR suite" at QMH, walking through the major clinical domains day by day: Vascular IR → Interventional Oncology → Musculoskeletal IR → Neuro IR → Aortic Intervention → Emergency/Urgent Cases, and finally closing with a summary of the roles, advantages, and scope of IR.
Why this matters for exams: The lecture tests your ability to (1) understand what IR procedures exist and when they are indicated/contraindicated, (2) compare IR alternatives against surgical approaches, (3) recognize complications, and (4) apply clinical reasoning to urgent case scenarios. Past papers commonly ask about TACE for HCC, percutaneous drainage, embolization for haemorrhage control, and nephrostomy — all covered here.
Learning Objectives (inferred from slide content and the IR 2025 supplementary deck) [1][2]:
- Define interventional radiology and understand its principles
- Know the scope: vascular and non-vascular procedures
- Understand indications, contraindications, and complications of common IR procedures
- Appreciate the perioperative evaluation of IR patients
- Recognize when IR provides an alternative to open surgery
Core Concept: What Is Interventional Radiology?
"A specialty in medicine providing minimally invasive, image-guided therapy for conditions in virtually all body systems." [1]
Key Analogy from Lecture – High Yield
Laparoscopy = keyhole surgery; IR = pinhole surgery (微創針孔手術 / 介入治療) [1]. This captures the essential advantage: even less invasive than laparoscopic surgery, using needles and catheters rather than ports and trocars.
First-principles explanation: IR leverages real-time imaging (fluoroscopy, ultrasound, CT, MRI) to guide needles, wires, catheters, and devices through the skin or blood vessels to the target. Because there is no large incision, patients experience less pain, shorter hospital stays, and faster recovery. The trade-off is that some procedures have higher reintervention rates compared to definitive surgery.
| Modality | Strengths | Limitations |
|---|---|---|
| Ultrasound | Real-time, no radiation, portable, flexible | Operator-dependent, obscured by bowel gas/bone |
| Fluoroscopy | Real-time, good for vascular work | Radiation exposure, 2D only (unless DynaCT) |
| CT | Precise localization, excellent anatomy | Radiation, intermittent imaging (not truly real-time) |
| MRI | Superior soft-tissue contrast | Slow, more contraindications, limited availability |
| Role | Examples |
|---|---|
| Diagnostic | Histological sampling (biopsy), treatment planning |
| Therapeutic – Vascular | Angioplasty/stenting, thrombolysis, embolization |
| Therapeutic – Non-vascular | Abscess drainage, nephrostomy, biliary drainage |
| Interventional Oncology | Ablation (RFA, MWA, cryoablation), TACE |
Minimally invasive procedures; provide alternative to surgery in suitable patients; hospital admission often not required; quick recovery, less pain and complications; generally safe and effective. [1]
| Contraindication | Explanation |
|---|---|
| Uncorrected bleeding diathesis | Platelets < 50,000/mm³ or INR > 1.5 — must correct first with platelets, FFP, or vitamin K |
| Inaccessible lesion | Surrounded by bone/vessels without a safe path — consider hydrodissection, pneumodissection, or repositioning |
| Uncooperative/unable to consent | Most IR is done under LA — patient cooperation required; consider anaesthetic support |
Vascular, Oncology, Gastrointestinal, Genitourinary, Neurointervention, Head and Neck, Musculoskeletal [1]
Monday – Vascular IR
PAE is a minimally invasive treatment that helps improve lower urinary tract symptoms (LUTS) caused by BPH. [1]
Why it works (mechanism) [1]:
- Infarcts with coagulative necrosis → volumetric reduction of the prostate → LUTS improvement
- Increased elasticity with relaxation of smooth muscle → less resistance to urinary flow
- Significant intravesical prostatic protrusion (IPP) reduction → symptomatic improvement
- Patient becomes free of indwelling catheter and urodynamic obstruction
Current evidence [1]:
- Early, mid, and long-term follow-up show significant improvement (P < 0.05) in IPSS, QoL, prostate volume (PV), post-void residual (PVR), and Qmax
- PSA reduced or remained stable
- High safety profile — no erectile disorder, no urinary incontinence
- Alternative to medications and surgeries, especially in elderly with comorbidities
PAE vs TURP – Exam Comparison Table
| Feature | PAE | TURP |
|---|---|---|
| Approach | Endovascular (femoral/radial access) | Transurethral |
| Anaesthesia | Local anaesthesia | Spinal/general |
| Hospital stay | Discharge next day | Several days |
| Erectile dysfunction | No | 5–10% |
| Retrograde ejaculation | No | > 80% |
| Urinary incontinence | No | Common for 6–8 weeks; persistent in 2–4% |
| Mortality | Very low | 0.2% (10% in those > 80 years) |
| Infertility | No | Yes |
Indications [1]:
- BPH with LUTS (based on IPSS score, or patient with permanent catheter)
- Prostate size > 35 grams
Contraindications [1]:
- Active infection (UTI, prostatitis)
- Biopsy-proven carcinoma prostate / bladder
Workup [1]:
- CT pelvic angiogram (to map the prostate arteries — highly variable anatomy)
- CBP, LFT, RFT
- PSA (to exclude malignancy)
Procedure [1]:
- Local anaesthesia
- Vascular access via femoral or radial artery
- ± Foley balloon
- Discharge next day
Risks of PAE [1]:
- Local vascular complications: haematoma, false aneurysm, distal embolisation
- Contrast reactions
- Acute urinary retention (0–25%)
- Non-target embolisation (1–8%)
- Transient haematospermia
- Transient haematuria
UFE is a procedure to shrink uterine fibroids. [1]
Current evidence [1]:
- UAE is advantageous over hysterectomy/myomectomy: shorter hospital stay, quicker return to activity, reduced blood transfusion likelihood
- Higher risk of minor complications
- Higher reintervention rate: 15–32% require surgery within 2 years (vs 7% after hysterectomy/myomectomy)
Indications [1]:
- Symptomatic fibroids (bleeding or bulk symptoms)
- Surgical indication (hysterectomy or multiple myomectomy candidate)
- No desire for future pregnancy
- Multiple intramural fibroids
- Adenomyosis
- Avoid pedunculated subserosal fibroids (risk of detachment and necrosis in peritoneal cavity)
Contraindications [1]:
- Viable pregnancy
- Asymptomatic woman
- Large pedunculated subserosal fibroid (confirmed on MRI)
Clinical assessment before UFE [1]:
- Chief complaint: bleeding vs. bulk
- Menstrual history: duration, frequency, heavy days, clots/"gushes", pad/tampon frequency
- Intermenstrual bleeding → rule out polyps, hyperplasia, cancer
- Pelvic symptoms: pressure/"bloating", pelvic pain, leg/back pain, urinary frequency/nocturia/obstruction, dyspareunia, constipation
- Reproductive history: infertility, miscarriages, desire for future fertility
Workup [1]:
- US and MRI pelvis — critical questions:
- Does the patient actually have fibroids?
- Where is/are the fibroid(s)? Location consistent with symptoms?
- Intracavitary? Size?
- Are the fibroids viable?
- How large is the uterus?
- Vascular anatomy?
- Other pathologies?
- CBP, LFT, RFT, clotting profile
Procedure [1]:
- Local anaesthesia
- Vascular access (femoral or radial)
- Discharge next day
Embolic agents [1]:
- PVA (polyvinyl alcohol) particles: 355–500 µm, 500–700 µm
- Embosphere (tris-acryl gelatin microspheres): 500–900 µm
- Occlude at the peri-fibroid plexus level → selective ischaemia of fibroids while sparing normal myometrium
Complications of UFE [1]:
- Transient amenorrhoea ~10%
- Permanent amenorrhoea: < 45 years ~3%, > 45 years ~15% (important for counselling!)
- Fibroid expulsion ~5%
- Access complications ~< 3%
- Uterine infection ~2%
- Venous thromboembolism < 1%
Exam Trap: Age and Amenorrhoea
Students commonly forget that permanent amenorrhoea risk rises sharply with age. In patients > 45, the risk is ~15% — this must be discussed during consent. This is one reason UFE is generally reserved for patients who do NOT desire future pregnancy.
Tuesday – Interventional Oncology
HCC is a vascular tumour supplied almost solely by the hepatic artery. [1]
Why TACE works (first principles) [1]:
- Normal liver parenchyma receives ~75% of its blood supply from the portal vein and ~25% from the hepatic artery
- HCC receives its blood supply almost entirely from the hepatic artery
- Iodized oil (lipiodol) is selectively taken up by HCC cells (because HCC lacks normal Kupffer cells that would normally clear lipiodol)
- Cytotoxic agent mixed into an emulsion with lipiodol is carried to tumour cells in high concentration and released slowly
- After delivering the chemotherapy-lipiodol emulsion, the feeding artery is embolized → dual effect of targeted chemotherapy + ischaemia
Complications of TACE [1]:
| Common | Uncommon |
|---|---|
| Post-embolization syndrome: nausea, vomiting, abdominal pain, loss of appetite, fever | Cholecystitis, upper GI bleeding, gastric/duodenal necrosis, acute pancreatitis, hepatic abscess, rupture |
Contraindications to TACE [1]:
1. Main portal vein tumour thrombosis — because embolizing the hepatic artery when the portal vein is already occluded would cause complete ischaemia and total liver infarction.
2. Extrahepatic metastases — TACE is a locoregional therapy, not systemic.
3. Poor liver function (serum bilirubin > 50 µmol/L) — insufficient hepatic reserve to tolerate ischaemic insult.
TACE Contraindications – Extremely High Yield
The most commonly tested contraindication is main portal vein tumour thrombosis. The reasoning is fundamental: liver has DUAL blood supply (hepatic artery + portal vein). If portal vein is already blocked by tumour thrombus, blocking the hepatic artery via TACE = no blood supply at all = liver necrosis/failure. This is a favourite exam question. [1][5]
The lecture references two staging systems [1]:
- Barcelona Clinic Liver Cancer (BCLC) Staging (2008) — international standard
- Hong Kong Liver Cancer (HKLC) Staging (2014) — local HK system, more aggressive treatment approach
Both guide treatment allocation (resection vs ablation vs TACE vs systemic therapy vs best supportive care) based on tumour characteristics, liver function (Child-Pugh), and performance status [5].
Case from lecture [1]: M/40 with alcohol cirrhosis, status post living donor liver transplant (LDLT), found to have critical stenosis at hepatic artery anastomosis.
Options: (1) Re-exploration (open surgery), or (2) IR – hepatic artery angioplasty + stenting (5mm vascular stent)
This illustrates IR's role in managing post-transplant vascular complications minimally invasively.
Ablation Techniques
The lecture extensively covers percutaneous ablation, which has expanded from liver alone (2015) to liver, kidney, bone, soft tissue tumour, thyroid, and lung by 2020 [1].
| Device | Mechanism | Advantages | Disadvantages |
|---|---|---|---|
| Radiofrequency Ablation (RFA) | Alternating current → frictional heating → coagulative necrosis | Most evidence, fast | Heat sink effect (blood vessels carry away heat → incomplete ablation near large vessels); incomplete ablation in large tumours |
| Microwave Ablation (MWA) | Electromagnetic waves → dielectric heating of water molecules | No heat sink, more homogeneous heat distribution | Increased risk of inadvertent damage to adjacent organs |
| Cryoablation | Argon gas → rapid cooling to −40°C → ice ball formation → cell death | Visible ice ball on imaging, less painful | Longer procedure time, risk of cryoshock |
| High Intensity Focused Ultrasound (HIFU) | Focused US waves → thermal coagulative necrosis + acoustic cavitation + tumour vasculature damage | Non-incisional, transcutaneous — no needle/electrode risk; can treat large tumours > 5 cm | Long treatment time; requires general anaesthesia; US or MRI guidance needed |
| Percutaneous Ethanol Injection (PEI) | Chemical destruction by absolute alcohol | Simple, cheap | Limited to small tumours |
| Irreversible Electroporation (IRE) | Electrical pulses → permanent cell membrane disruption | Preserves connective tissue scaffolding | Requires GA, cardiac synchronization |
Heat Sink Effect – Must Know
The heat sink effect is the main limitation of RFA. Blood flowing through adjacent vessels acts as a "heat sink," carrying thermal energy away from the ablation zone. This leads to incomplete ablation at the margin near vessels. MWA overcomes this because microwave energy generates more uniform heating independent of local blood flow. This is a common exam discriminator between RFA and MWA.
- Day procedure, LA/sedation, US guidance
- Hydrodissection / perithyroidal infusion to protect surrounding structures
- Results: mean volume reduction 84.11%, therapeutic success 91.6%, complete disappearance 28%
- Complications: total 3.3%, major 1.4%
- Minor: haematoma, transient hoarseness, skin burn
- Major: persistent hoarseness, vessel injury, abscess/haematoma requiring surgery
Comparison: Ablation vs Thyroidectomy [1]:
| Feature | Thyroidectomy | Ablation (RFA) |
|---|---|---|
| Cure rate | Higher, immediate | Lower (may need retreatment) |
| Cancer treatment | Can treat cancer | Limited role |
| Cosmesis | Longer scar | Better cosmesis |
| Thyroid function | Hypothyroidism likely | Thyroid function preserving |
| Morbidity | ~7% | ~3% |
| Hospital stay | Overnight | Day procedure |
| Mortality | 0.3% | Very low |
- Renal cell carcinoma (T1a < 4 cm) — alternative to partial nephrectomy in elderly/comorbid patients [6]
- Painful bone metastases — palliative pain relief
- Bone and soft tissue tumours
- Hydrodissection: injecting fluid (saline/D5W) to create a buffer zone between the ablation target and adjacent structures
- Pneumodissection: injecting air/CO₂ for the same purpose
- Artificial ascites: injecting fluid into the peritoneal cavity to separate liver tumours from adjacent bowel or diaphragm
- CEUS (contrast-enhanced ultrasound) localization: using microbubble contrast to identify the tumour in real time during ablation
Wednesday – Musculoskeletal IR
Guidance modalities:
- US: real-time, best for soft tissue
- CT: precise localization, deep structures, bone
- Fluoroscopy: real-time with 3D views / DynaCT capability
Critical concept: Biopsy approach must follow surgical anatomy [1]:
- For a shoulder mass: biopsy through the anterior deltoid
- Avoid the deltopectoral groove (contains the cephalic vein, crucial for surgical approach)
- Avoid the posterior deltoid/neurovascular bundle (axillary nerve, circumflex humeral vessels)
- The biopsy tract must be planned so it can be excised en bloc with the tumour at definitive surgery (this is the Enneking principle)
Case examples from lecture [1]:
- M/36 left shoulder mass → biopsy through anterior deltoid
- M/35 neck pain with cervical spine lesion → biopsy revealed plasmacytoma
- F/40 left acetabular lytic lesion → prone position biopsy
- 28/F lytic C6 tumour
- F/44 left abdominal wall mass → desmoid tumour → treated with RFA (since resection has high recurrence, and medical oncology is not curative)
Vertebroplasty provides pain relief (80–97%), mechanical stabilization, reduces vertebral bulge, reduces risk of burst fracture, and has an antitumoral effect of PMMA. [1]
Mechanism of pain relief: PMMA cement undergoes exothermic polymerization → thermal destruction of pain nerve endings + mechanical stabilization prevents micro-motion at fracture site → reduced pain.
Cement (PMMA) [1]:
- Radio-opaque
- Powder + monomer mixture
- Exothermic polymerization: liquid → paste → solid
- Instruments: 8, 10, 12G needles; syringe; cement mixture device
Indications for vertebroplasty [1]:
- Painful bone tumour (metastasis, myeloma, lymphoma)
- Aggressive vertebral haemangioma
- Osteoporotic fracture
- Kümmel's disease (avascular necrosis of vertebral body → delayed vertebral collapse)
Post-procedure care [1]:
- Prone until cement hardens
- Bed rest 1–2 hours
- CT to check cement distribution
- Pain score (VAS)
- Discharge next day
Cementoplasty in other locations [1]:
- Acetabulum, femoral condyles, tibial ends, talus and calcaneus
- Combined with ablation (e.g., cryoablation) and/or RT for consolidation of impending pathological fractures
Thursday – Neuro IR
Case: M/83, PMH of AF and hyperlipidaemia, presented with sudden left-sided weakness.
Options [1]:
- Systemic thrombolysis (IV rtPA)
- Intra-arterial (IA) thrombolysis / mechanical thrombectomy
The lecture shows pre- and post-thrombectomy angiographic images demonstrating successful recanalization.
Key concept: For large vessel occlusion (LVO) strokes, mechanical thrombectomy ± IV thrombolysis is superior to IV thrombolysis alone. The time window for thrombectomy can extend to 24 hours with appropriate imaging selection (perfusion mismatch) [7].
Case: 59/F with sudden severe headache (thunderclap headache → SAH until proven otherwise).
Next investigation: CTA Head is the most appropriate next step [1] — non-invasive, widely available, high sensitivity for aneurysm detection. DSA (digital subtraction angiography) is the gold standard but is invasive and typically done when intervention is planned.
Case progression: Giant ICA terminus aneurysm → treated with coil occlusion (endovascular coiling fills the aneurysm sac with platinum coils → promotes thrombosis within the aneurysm → prevents rupture).
For a contralateral small cavernous aneurysm: also treated with coil occlusion. In some cases, parent vessel occlusion with balloon test occlusion (PBO) is performed.
Complications of coil embolization [1]:
| Complication | Mechanism |
|---|---|
| Thromboembolic | Clot formation on coil ball/catheter; pushing clot out of aneurysm |
| Aneurysm rupture | More likely in already-ruptured aneurysms |
| Device malfunction | Premature detachment of coil; unravelling |
| Vascular damage | Spasm, dissection |
Thoracic Endovascular Aortic Repair (TEVAR) and Fenestrated EVAR [1]
Case: M/71, 2012 thoracic aortic aneurysm → open aortic replacement (T4–9). 2016 recurrent aneurysm at thoracolumbar junction.
Treatment: 1st TEVAR → 2nd TEVAR → 4-fenestrated EVAR (3 aortic stents + 4 visceral stents) [1]
Why fenestrated? Standard endovascular stent grafts cover the aorta but can occlude vital branch vessels (coeliac, SMA, renal arteries). Fenestrated grafts have custom-made holes (fenestrations) aligned with these branch vessels, allowing stents to be placed through the fenestrations into the branches → maintains visceral perfusion while excluding the aneurysm.
This complex procedure required 3 radiologists + 1 cardiothoracic surgeon + 1 anaesthetist, 10 hours in the angiosuite [1].
Weekend – Urgent/Emergency Cases
Scenario: 50-year-old man with stones disease, hypotension and tachycardia 4 hours after PCNL.
Most likely cause of haematuria: PCNL-related [1] — iatrogenic vascular injury during percutaneous nephrostomy tract creation.
Finding: Pseudoaneurysm on angiography → treated with selective embolization
This is a classic IR emergency: post-procedural bleeding managed by identifying and embolizing the culprit vessel rather than re-exploration.
Scenario: 42-year-old woman, 2–3 weeks RLQ pain, now fever and vomiting.
Investigation: CT scan of the abdomen (or USS) → large cystic mass adjacent to caecum = appendix abscess
Management: CT-guided drainage of the abscess + IV antibiotics [1] — NOT straight to theatre (abscess must be drained first; operating in an inflamed field increases complications; interval appendicectomy can be performed later).
Appendix Abscess Management – High Yield
CT-guided percutaneous drainage + IV antibiotics is the standard initial management for a well-formed appendix abscess. This is followed by interval appendicectomy approximately 6–8 weeks later after inflammation has settled. Sending the patient straight to theatre risks more extensive surgery and complications.
Scenario: 58-year-old woman with recurrent pyogenic cholangitis (RPC), fevers/chills/rigors, high WCC, deranged LFTs.
CT findings: Dilated intrahepatic ducts + multiple hypodense liver abscesses [1]
Management progression:
- IV antibiotics → fever did not settle
- PTBD (percutaneous transhepatic biliary drainage) attempted → during the procedure, blood noted draining from catheter, Hb dropped by 1 g/dL
- CT showed blood in the biliary tree (haemobilia)
- Next step: Hepatic arteriogram ± embolization [1]
- Left hepatic arteriogram showed extravasation and contrast staining
- Embolization of the left hepatic artery with gelfoam was performed successfully
Key teaching point: Haemobilia (bleeding into the biliary tree) after hepatobiliary procedures should prompt hepatic arteriography to identify and embolize the bleeding vessel. This is far safer than taking the patient to theatre.
| Category | Procedures |
|---|---|
| Arterial | Balloon angioplasty and stenting; thrombolysis; haemorrhage control and embolization |
| Venous | Central venous access (e.g., PICC, dialysis catheter); IVC filter; fistula intervention |
| Endovascular IR [2] | Creation of vascular access; stop bleeding (GI, GU, head & neck); open blockages (stroke, PE, renal artery stenosis); treat vascular abnormalities (aneurysms, fistulae, AVMs); treat hypervascular cancers (HCC); treat benign hypervascular diseases (fibroids, BPH, varicocele) |
- CT-guided lung biopsy is the classic example
- Also: liver biopsy (US-guided), renal biopsy, bone biopsy (CT/fluoroscopy-guided)
- Fine-needle biopsy accuracy: 80–95%, complication rate < 2% [4]
Before any IR procedure:
- Check INR, PT/PTT, blood counts — correct bleeding diathesis before procedure [3]
- Check period of fasting [3]
- Obtain informed consent [3]
- Check renal function — contrast use may require eGFR assessment
- Direct communication with radiologist on-call [3]
- Know your patient — clinical context is essential for choosing the right procedure [3]
Integration with Related Material
Per Prof TT Cheung's HCC lecture [5] and Maksim Surgery Notes [5]:
- TACE is a palliative option in BCLC intermediate stage (B)
- HKLC staging is more aggressive and may recommend TACE even in some patients who would get best supportive care under BCLC
- Post-lipiodol CT scan: HCC shows uptake on Day 10 due to lack of Kupffer cells
- Curative options: resection, local ablation, liver transplant
Per Maksim Surgery Notes [8]:
- IR mesenteric angiogram enables super-selective catheterisation and embolisation for GI bleeding
- Embolic agents:
- Temporary: absorbable gelatin sponge (Gelfoam) — useful but higher rebleeding rate
- Permanent: coils (most effective), particles (for bleeding tumours, risk of bowel ischaemia), liquid agents e.g., NBCA
Past paper Q2 (2020) [9]: A 45-year-old lady with carcinoma of cervix and hydronephrosis → answer is percutaneous nephrostomy. This is a classic IR procedure for obstructive uropathy.
Per Block A VTE lecture [10]: IVC filters have very limited role — only when anticoagulation is contraindicated and there is a need to prevent PE. They are temporary and must be removed when bleeding risk subsides, or they become endothelialized and irremovable.
Per Ryan Ho Urogenital [6]: T1 RCC (< 4 cm) in elderly/comorbid patients → local ablation (RFA, cryoablation) or active surveillance is an alternative to partial nephrectomy.
Exam Intelligence
- TACE contraindications — especially main portal vein tumour thrombosis
- PAE vs TURP — advantages of PAE (no incontinence, no retrograde ejaculation)
- UFE indications/contraindications — NOT for patients wanting future pregnancy; avoid pedunculated subserosal fibroids
- Percutaneous nephrostomy — for obstructive uropathy with deteriorating renal function
- CT-guided abscess drainage — appendix abscess management
- Heat sink effect — why RFA may fail near blood vessels; MWA advantage
- Vertebroplasty indications — painful metastases, osteoporotic fractures
- Embolization for post-procedural bleeding — post-PCNL pseudoaneurysm
- Stroke thrombectomy — for large vessel occlusion
| Trap | Correct Understanding |
|---|---|
| Confusing "embolization" for "embolism" | Embolization = therapeutic occlusion of a vessel; embolism = pathological occlusion |
| Thinking UFE is safe in pregnancy | Viable pregnancy is an absolute contraindication |
| Assuming all HCC can have TACE | Main portal vein thrombus = absolute contraindication |
| Believing RFA and MWA are identical | RFA suffers from heat sink; MWA does not |
| Ordering percutaneous biopsy when contraindicated | Check platelet count (> 50 × 10⁹) and INR (< 1.5) first |
Q1: A 65-year-old man with known HCC and portal vein tumour thrombus is referred for TACE. Is this appropriate? Why or why not?
- Answer: No. Main portal vein tumour thrombosis is an absolute contraindication to TACE because embolizing the hepatic artery when the portal vein is already occluded would cause complete hepatic ischaemia.
Q2: A patient with BPH (prostate volume 60g, IPSS 25) is concerned about sexual side effects of TURP. What alternative would you suggest?
- Answer: Prostate artery embolization (PAE). It has lower risk of urinary incontinence, no retrograde ejaculation, and no erectile dysfunction compared to TURP.
Q3: Name three indications for vertebroplasty.
- Answer: (1) Painful bone tumour (metastasis, myeloma, lymphoma), (2) Osteoporotic fracture, (3) Aggressive vertebral haemangioma, (4) Kümmel's disease.
Q4 (from past paper pattern): A 45-year-old lady with carcinoma of the cervix has hydronephrosis and deteriorating renal function. What is the most appropriate management?
- Answer: Percutaneous nephrostomy.
Q5: What is the main disadvantage of RFA compared to MWA?
- Answer: Heat sink effect — blood vessels adjacent to the tumour carry away heat, leading to incomplete ablation. MWA generates more homogeneous heat distribution unaffected by blood flow.
Q6: A 42-year-old woman presents with RLQ pain, fever, and a CT showing an appendix abscess. What is the initial management?
- Answer: CT-guided percutaneous drainage of the abscess + IV antibiotics. Interval appendicectomy 6–8 weeks later.
High Yield Summary
Interventional Radiology = minimally invasive, image-guided diagnosis and therapy ("pinhole surgery").
Key procedures to know:
- PAE: for BPH/LUTS; lower sexual side effects than TURP; contraindicated in active infection or prostate cancer
- UFE: for symptomatic fibroids; NOT for future pregnancy; avoid pedunculated subserosal fibroids
- TACE: for HCC; exploits hepatic artery-dependent tumour supply + lipiodol uptake; CONTRAINDICATED in main PV thrombus, extrahepatic mets, bilirubin > 50
- Ablation: RFA (heat sink!), MWA (no heat sink), cryoablation (for RCC T1a, painful mets), HIFU (non-incisional but requires GA)
- Vertebroplasty: painful metastases, osteoporotic fractures, aggressive haemangioma
- Thrombectomy: for LVO stroke
- Coil embolization: for intracranial aneurysms; complications include thromboembolism, rupture, device malfunction
- Emergency embolization: post-PCNL pseudoaneurysm, haemobilia post-PTBD
- CT-guided drainage: appendix abscess, liver abscess
- Always check: INR, platelets, consent, fasting before IR procedures
Active Recall - Interventional Radiology
[1] Lecture slides: GC 014. How can interventional radiology help patient management.pdf [2] Lecture slides: IR 2025_VLau.pdf (Contents, Endovascular IR scope) [3] Lecture slides: GC 013. Emergency radiology.pdf (p3, urgent request checklist) [4] Senior notes: Ryan Ho Diagnostic Radiology.pdf (p78–79, IR section) [5] Senior notes: Maksim Surgery Notes.pdf (p125, HCC staging and TACE) [6] Senior notes: Ryan Ho Urogenital.pdf (p148, RCC management including cryoablation) [7] Lecture slides: GC 087. Sudden hemiplegia dysphagia.pdf / Cererbrovascular disease.pdf (stroke management context) [8] Senior notes: Maksim Surgery Notes.pdf (p79, embolization for GI bleeding) [9] Past papers: 2020 Fourth Summative Assessment MCQ paper.pdf (Q2, percutaneous nephrostomy) [10] Senior notes: Block A - Leg swelling and chest pain_ deep vein thrombosis; pulmonary embolism; Thrombophilia.pdf (p26, IVC filter)
GC013 Emergency Radiology
Emergency radiology is the subspecialty of radiology focused on the rapid interpretation of imaging studies to diagnose acute, life-threatening conditions such as trauma, stroke, and vascular emergencies in urgent clinical settings.
GC015 Imaging Of The Head And Neck
Diagnostic imaging of the head and neck encompasses radiographic, CT, MRI, and ultrasound techniques used to evaluate structures such as the brain, sinuses, orbits, salivary glands, thyroid, vasculature, and aerodigestive tract for pathology.