hình ảnh u gan sau rfa (1)

The ablation area must be 10mm larger than the diameter of the tumor... Images of CT Findings after RFASchema shows successful ablation At initial follow-up CT Immediate : tumor, ablat

Bệnh nhân nam 37 tuổi được chẩn đoán ung thư gan MRI

Bệnh nhân được điều trị RFA

CT sau 1 ngày

So sánh hình ảnh trước đốt và sau đốt

Với hình ảnh CT :

- Tổn thương u đã được loại bỏ ?

- Viền ngấm thuốc là hình ảnh khối u còn tăng sinh mạch hay

là 1 dạng tổn thương khác ?

- Kết quả đọc “ khối u còn ngấm thuốc viền” có phù hợp ?

Images of CT Findings after RFA of Hepatic Tumors

Radiofrequency Ablation – RFA

Indication:

• Primary liver cancer or metastatic cann’t surgery

• Primary or secondary liver cancer: 1 tumor or maximum of 3 tumor

• Optimal indications for tumors less 5 cm To date, the

indication is also enlarged for tumors up to 7 cm

- Liver tumors in a position at high risk of high-frequency thermal engineering

• Liver tumors are near large blood vessels

• Tumor is close to the liver capsule (<5mm)

• Liver tumors are located near the gallbladder

• Liver tumors near the bile ducts

Are relative contraindications

- Liver cancer has portal metastasis or distal metastasis

-Multiple tumor of liver cancer

- Cirrhosis of the Stage Child - Pugh C.

The ablation area must be 10mm larger than the diameter of the tumor

Images of CT Findings after RFA

Schema shows successful ablation

At initial follow-up CT 

Immediate : tumor, ablative marginand and is

surrounded by a ring of enhancement (solid gray circle) that usually disappears by 1-month follow-up CT

The ablation zone involutes gradually over the next several years.

Schema shows incomplete ablation, with a crescent-shaped remnant of

tumor tissue (*) at the margin of the ablation zone

If the volume of residual tumor tissue

is minimal, it is difficult to differentiate from the enhanced ring of benign

tissue surrounding the ablation zone

If the ablative margin is not

wide enough, a small nodular tumor (*) may appear adjacent

to the margin

Before RFA 20 minutes after ablation

T2-weighted MRI image obtained before ablation arterial phase CT image obtained 20

minutes after ablation shows coverage of the index tumor with a sufficient ablative margin and a surrounding ring of benign enhancement indication of a benign physiological response

to heat trauma

After 3-month After 1 year

• In addition, tiny air bubbles produced during ablation may be seen at immediate follow-up CT

• These air bubbles also usually resolve within 1 month

Before RFA Immediate After 1 month

Atypical CT Features of the RFA Zone

Hepatic Abscess

• This problem has been reported to

be 0.3%–2.0%

• The clinical symptoms include a

relatively persistent fever and pain

Because fever and pain are also

common symptoms of postablation

syndrome.

• Persistent fever over 2 weeks may be

indicative of a hepatic abscess 

Bile Duct Change

Bile duct change after RFA is relatively

common, but symptomatic bile duct changes requiring treatment are rare

Bile duct dilatation peripheral to the ablation zone is the most commonly observed change

Transient bile duct dilatation caused by biliary stasis

However, if bile duct dilatation persists on

follow-up CT images that is an irreversible

change

• A biloma appears as a fluid

collection that surrounds the

necrotic tissue in the RF ablation zone

• Bilomas caused by bile leakage from injured ducts in the ablation zone usually resolve within 4

months and, in most cases, have

no clinical significance

• Symptomatic bilomas may be

treated with percutaneous

drainage 

Pseudoaneurysm Formation

• Pseudoaneurysm of the hepatic artery is a rare complication

• This complication is rare because the hepatic vessels near the tumor are protected by the heat-sink effect of blood flow 

and include abdominal

pain and fever

• Treatment is conservative

• The typical CT finding in the RFA zone is a nonenhancing

area of low attenuation that gradually involutes

• However, atypical findings also may be observed

• These include residual tumor tissue, delayed complications, and local tumor progression requiring further management

• We should be aware of both the typical and the atypical CT findings in the RFA zone and their clinical significance