# Clinical Cases: Interventional Radiology and Special Topics

## Case 1: Transcatheter Arterial Chemoembolization (TACE) for Hepatocellular Carcinoma

### Patient Demographics
- **Age:** 62 years
- **Sex:** Male

### Chief Complaint
Incidental liver mass found on surveillance imaging

### Presenting Symptoms
The patient has a history of hepatitis C cirrhosis (treated and cured with direct-acting antivirals 4 years ago) and undergoes routine hepatocellular carcinoma (HCC) surveillance. His most recent ultrasound showed a new 3.5 cm liver lesion. He is asymptomatic with no abdominal pain, jaundice, weight loss, or encephalopathy. He continues to abstain from alcohol.

### Physical Exam Findings
- **Vital Signs:** Within normal limits
- **General:** Well-appearing male, no jaundice, no asterixis
- **Abdomen:** Soft, non-tender, liver edge palpable 2 cm below costal margin, no ascites, no splenomegaly
- **Stigmata of Liver Disease:** Spider angiomata on chest, palmar erythema
- **Laboratory:**
  - AFP: 287 ng/mL (elevated)
  - Child-Pugh Score: A5 (compensated cirrhosis)
  - MELD Score: 8
  - Platelets: 118,000/uL
  - INR: 1.2
  - Albumin: 3.6 g/dL
  - Bilirubin: 1.1 mg/dL

### Imaging Findings and Interpretation
**Multiphasic CT/MRI Liver (LI-RADS Protocol):**

**Arterial Phase:**
- 3.8 cm mass in segment 6 of the liver
- Arterial phase hyperenhancement (APHE) - enhances more than background liver
- No other suspicious lesions

**Portal Venous Phase:**
- Washout appearance - mass becomes hypodense relative to liver
- Enhancing capsule appearance visible

**Delayed Phase:**
- Persistent capsule enhancement
- Central hypointensity (washout confirmed)

**LI-RADS Classification:** LR-5 (Definitely HCC)
- Meets criteria: >20mm observation with APHE + washout + enhancing capsule
- No threshold growth needed given other features

**Additional Findings:**
- Cirrhotic liver morphology with nodular contour
- Patent portal vein, no tumor thrombus
- No extrahepatic disease on CT chest/abdomen/pelvis
- Small volume ascites

**Staging:**
- BCLC Stage A (single tumor <5cm, preserved liver function)
- Milan Criteria: Within (single tumor <=5cm)

### Diagnosis
Hepatocellular carcinoma (LR-5), BCLC Stage A, in setting of HCV cirrhosis; candidate for curative treatment

### Management
1. **Multidisciplinary Tumor Board Discussion:**
   - Hepatology, surgical oncology, interventional radiology, medical oncology

2. **Treatment Options Considered:**
   - **Liver transplant:** Listed for transplant (within Milan criteria)
   - **Surgical resection:** Possible but higher risk given cirrhosis
   - **Ablation:** Could be considered for lesion of this size
   - **TACE:** Selected as bridge to transplant

3. **TACE Procedure (Bridging Therapy):**
   **Pre-procedure:**
   - NPO after midnight
   - IV access, prophylactic antibiotics
   - Conscious sedation

   **Procedure:**
   - Right common femoral artery access
   - Celiac arteriogram: Identifies hepatic arterial anatomy
   - Selective catheterization of segment 6 feeding artery
   - Tumor blush confirmed on angiography
   - Drug-eluting beads loaded with doxorubicin (100-300 micron)
   - Embolization to near-stasis
   - Completion angiogram: No residual tumor blush

   **Post-procedure:**
   - Post-embolization syndrome (fever, pain, nausea) managed supportively
   - Discharged day 2

4. **Follow-up Imaging (4 weeks post-TACE):**
   - mRECIST assessment: Complete response
   - No viable enhancing tumor
   - Dense lipiodol retention (if conventional TACE) or non-enhancing treatment zone

5. **Transplant Listing:**
   - Maintained on transplant list
   - MELD exception points for HCC
   - Received liver transplant 8 months later
   - Explant pathology: 100% tumor necrosis (pathologic complete response)

### Radiological Image

![TACE Angiography](case_01_image.jpg)

**Image Description:** Selective hepatic arteriogram during TACE procedure showing hypervascular hepatocellular carcinoma with characteristic tumor blush (abnormal tumor vascularity). The catheter is positioned in the feeding artery for selective chemoembolization.

**Source:** Wikimedia Commons - "Hepatic angiography"
**URL:** https://commons.wikimedia.org/wiki/File:Angiography_during_TACE.jpg
**License:** Creative Commons Attribution-Share Alike 4.0 International

---

## Case 2: Gastrointestinal Bleeding - Angiography and Embolization

### Patient Demographics
- **Age:** 74 years
- **Sex:** Male

### Chief Complaint
Bright red blood per rectum with hemodynamic instability

### Presenting Symptoms
The patient presented to the emergency department with multiple episodes of large-volume bright red blood per rectum that began 3 hours prior to arrival. He reports passing approximately 1 liter of blood with clots. He feels lightheaded and nearly syncopized at home. Medical history includes hypertension, atrial fibrillation on apixaban, and osteoarthritis for which he takes daily NSAIDs.

### Physical Exam Findings
- **Vital Signs:** BP 88/54 mmHg, HR 118 bpm, RR 22/min, Temp 36.4C
- **General:** Pale, diaphoretic, anxious
- **Cardiovascular:** Tachycardic, irregular rhythm
- **Abdomen:** Soft, mildly tender in left lower quadrant, no peritoneal signs
- **Rectal Exam:** Gross blood, no masses
- **Laboratory:**
  - Hemoglobin: 7.2 g/dL (baseline 12.8 g/dL per records)
  - Platelets: 198,000/uL
  - INR: 1.4 (on apixaban)
  - Creatinine: 1.4 mg/dL

### Imaging Findings and Interpretation
**Initial Resuscitation:**
- 2 large-bore IVs, crystalloid resuscitation
- Massive transfusion protocol activated
- Type and crossmatch for 6 units PRBCs
- Reversal agent for apixaban (andexanet alfa) considered

**CT Angiography Abdomen/Pelvis:**

**Arterial Phase:**
- **Active Extravasation:** Focal area of contrast extravasation into the sigmoid colon lumen
- Extravasation appears to arise from a branch of the inferior mesenteric artery (sigmoid branch)
- **Blush increases on delayed phase** - confirms active bleeding

**Source Identification:**
- Multiple diverticula throughout the sigmoid colon
- Bleeding appears to originate from the mouth of a diverticulum
- **Sentinel clot:** Highest-attenuation clot adjacent to extravasation site

**Colonoscopy vs. Angiography Decision:**
Given hemodynamic instability and localized bleeding source on CTA, decision made to proceed directly to angiography for potential embolization rather than colonoscopy.

### Interventional Radiology Procedure
**Mesenteric Angiography and Embolization:**

**Diagnostic Angiography:**
- Right common femoral artery access
- Flush aortogram: IMA identified
- Selective IMA arteriogram: Identifies sigmoid branches
- Superselective sigmoid artery catheterization
- **Active extravasation confirmed:** Contrast blush into colonic lumen from branch of sigmoid artery, correlating with CTA findings

**Embolization:**
- Microcatheter advanced to the bleeding branch
- Embolization with microcoils (2mm x 4cm)
- Completion angiogram: No residual extravasation
- Preserved flow to adjacent bowel segments

**Post-Procedure Findings:**
- Hemorrhage controlled
- Hemodynamic stabilization achieved
- No immediate complications

### Diagnosis
Acute lower gastrointestinal bleeding secondary to diverticular hemorrhage; treated with angiographic embolization

### Management
1. **Post-Embolization Care:**
   - ICU admission for monitoring
   - Serial abdominal exams for ischemia
   - Serial hemoglobin checks
   - Transfusion to maintain Hgb >7 g/dL

2. **Post-Procedure Course:**
   - No further bleeding episodes
   - Hemoglobin stabilized at 8.8 g/dL
   - Resumed oral intake day 2
   - No evidence of bowel ischemia

3. **Medication Management:**
   - NSAIDs permanently discontinued
   - Anticoagulation: Discussed risks/benefits; restarted apixaban at reduced dose after 7 days given high stroke risk (CHA2DS2-VASc score 5)

4. **Outpatient Follow-up:**
   - Colonoscopy in 4-6 weeks (after healing) to evaluate for other pathology
   - PPI therapy added for gastroprotection
   - Discussed high-fiber diet for diverticular disease

### Radiological Image

![GI Bleeding Angiography](case_02_image.jpg)

**Image Description:** Selective mesenteric arteriogram demonstrating active gastrointestinal hemorrhage. Contrast extravasation (blush) is visible extending from a branch of the mesenteric artery into the bowel lumen, confirming the site of active bleeding amenable to transcatheter embolization.

**Source:** Wikimedia Commons - "Angiography showing gastrointestinal bleeding"
**URL:** https://commons.wikimedia.org/wiki/File:Angiography.jpg
**License:** Creative Commons Attribution-Share Alike 3.0 Unported

---

## Case 3: CT-Guided Lung Biopsy

### Patient Demographics
- **Age:** 67 years
- **Sex:** Female

### Chief Complaint
Incidental pulmonary nodule found on CT

### Presenting Symptoms
The patient underwent CT of the abdomen for evaluation of abdominal pain (ultimately diagnosed as diverticulitis, now resolved). The CT incidentally demonstrated a lung nodule at the lung bases. She is asymptomatic from a pulmonary standpoint with no cough, hemoptysis, dyspnea, or weight loss. She has a 35 pack-year smoking history and quit 5 years ago.

### Physical Exam Findings
- **Vital Signs:** Within normal limits
- **General:** Well-appearing, no distress
- **Pulmonary:** Clear to auscultation bilaterally, no wheezes or crackles
- **Lymph Nodes:** No cervical or supraclavicular lymphadenopathy
- **No Clubbing**

### Imaging Findings and Interpretation
**Chest CT (Dedicated):**
- **Nodule Characteristics:**
  - Location: Right lower lobe, peripheral
  - Size: 2.2 x 1.8 cm
  - Morphology: Spiculated margins with pleural tail
  - Density: Solid, no calcification
  - No cavitation
- **Lung-RADS Category:** 4B (>15mm solid nodule with suspicious features)
- **Probability of Malignancy:** >15% based on size, morphology, and smoking history
- **Mediastinum:** No enlarged lymph nodes (all <1cm short axis)
- **Other Findings:** Mild centrilobular emphysema

**PET-CT:**
- Nodule demonstrates FDG avidity with SUVmax 6.8
- No FDG-avid mediastinal or hilar lymph nodes
- No evidence of distant metastatic disease

**Risk Assessment:**
Using the Brock Model (lung cancer prediction): Estimated probability of malignancy >40% given size, spiculation, smoking history, and FDG avidity.

### Interventional Radiology Procedure
**CT-Guided Percutaneous Lung Biopsy:**

**Pre-Procedure Planning:**
- Review of CT for optimal approach
- Shortest path to lesion avoiding fissures and major vessels
- Patient positioned prone for posterior approach
- INR 1.1, platelets 245,000 (adequate)
- Informed consent obtained discussing pneumothorax and hemorrhage risk

**Procedure:**
- CT guidance used for real-time needle localization
- Local anesthesia with 1% lidocaine
- Coaxial technique: 19-gauge introducer needle advanced to lesion margin
- Position confirmed on CT
- 20-gauge core biopsy needle through introducer
- 4 core samples obtained
- Samples submitted for histology and molecular testing
- Post-biopsy CT: Small pneumothorax (~10%), no intervention required

**Immediate Post-Procedure:**
- Positioned biopsy side down
- Monitored in recovery for 2 hours
- Repeat CXR at 2 hours: Stable small pneumothorax
- Discharged with instructions for pneumothorax precautions

### Pathology Results
- **Histology:** Non-small cell lung carcinoma, adenocarcinoma subtype
- **Molecular Testing:**
  - EGFR: Wild type
  - ALK: Negative
  - ROS1: Negative
  - PD-L1: 60% (high expression)
  - KRAS: G12C mutation positive

### Diagnosis
Stage IA2 non-small cell lung cancer (adenocarcinoma), KRAS G12C mutant, PD-L1 high

### Management
1. **Staging Workup:**
   - Brain MRI: Negative for metastases
   - PFTs: FEV1 78% predicted, adequate for surgery

2. **Multidisciplinary Tumor Board:**
   - Thoracic surgery, medical oncology, radiation oncology, pulmonology

3. **Treatment Plan:**
   - Stage IA2 disease: Surgical candidate
   - Video-assisted thoracoscopic surgery (VATS) right lower lobectomy with mediastinal lymph node dissection
   - Final pathology: pT1bN0M0, Stage IA2
   - No adjuvant therapy recommended for Stage IA

4. **Surveillance:**
   - CT chest every 6 months for 2 years, then annually
   - Smoking cessation counseling reinforced
   - PCP follow-up for ongoing lung cancer screening of remaining lung

### Radiological Image

![CT-Guided Lung Biopsy](case_03_image.jpg)

**Image Description:** CT-guided percutaneous lung biopsy demonstrating the biopsy needle positioned within a peripheral lung nodule. CT guidance allows real-time visualization of needle trajectory and confirmation of accurate sampling position within the target lesion.

**Source:** Radiopaedia - Educational image of CT-guided biopsy
**URL:** https://radiopaedia.org/articles/ct-guided-lung-biopsy
**License:** Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported

---

## Learning Points

1. **TACE for HCC:** Transarterial chemoembolization exploits the dual blood supply of the liver (portal vein supplies normal liver; hepatic artery preferentially supplies tumors). TACE delivers chemotherapy directly to the tumor while inducing ischemia, and can serve as bridge therapy to transplant or definitive treatment for intermediate-stage HCC.

2. **CTA for GI Bleeding:** CT angiography can detect active bleeding at rates as low as 0.3-0.5 mL/min and localizes the source for targeted intervention. The sentinel clot sign helps identify the bleeding source. When active extravasation is seen, angiographic embolization often provides definitive hemostasis without surgery.

3. **CT-Guided Biopsy Technique:** Coaxial technique allows multiple samples through a single pleural puncture, reducing pneumothorax risk. The tract should be planned to avoid fissures and major vessels. Post-biopsy pneumothorax occurs in 15-20% of cases but most are small and managed conservatively.

4. **Lung-RADS and Nodule Management:** Lung-RADS provides standardized reporting for screening CT findings. Category 4B nodules (>15mm with suspicious features) warrant tissue diagnosis. PET-CT helps assess metabolic activity and screen for metastatic disease before proceeding with biopsy.