Interventional radiology (IR) covers a broad range of minimally invasive procedures that use imaging tools like X-ray, ultrasound, CT scans, and MRI to guide tiny instruments through the body. Rather than making large incisions, interventional radiologists typically work through a needle puncture or a small catheter inserted into a blood vessel. The procedures span nearly every organ system, from opening blocked arteries to destroying tumors to draining infections.
Opening Blocked Blood Vessels
Vascular interventions make up a large share of IR work. The most common is angioplasty: a balloon-tipped catheter is threaded into a narrowed or blocked artery, and the balloon is inflated to push the vessel open and restore blood flow. Once the artery is open, a stent (a small metal mesh tube) is often placed inside to act as a scaffold and keep the vessel from collapsing again. The stent stays in permanently.
These procedures treat peripheral artery disease in the legs, narrowed arteries supplying the kidneys or brain, and blockages in dialysis access sites. Some newer balloon catheters are coated with medication that absorbs into the vessel wall during inflation, helping prevent the artery from narrowing again after the balloon is removed.
On the venous side, IR treats deep vein thrombosis by breaking up or removing blood clots using catheters. Filters can also be placed inside the large vein leading to the heart (the inferior vena cava) to catch clots before they reach the lungs, though these devices carry their own risks, with complication rates for issues like filter migration reported as high as 40% in some studies.
Treating Tumors Without Surgery
Interventional oncology has become one of the fastest-growing areas of IR. These procedures target tumors directly, often in patients who aren’t candidates for traditional surgery.
Thermal ablation destroys tumors by inserting a needle-like probe directly into the growth and delivering extreme heat (radiofrequency or microwave energy) or extreme cold (cryoablation). This is commonly used for small liver tumors, kidney cancers, and lung nodules. The probe is guided into position using CT or ultrasound imaging.
Chemoembolization delivers chemotherapy drugs directly into the arteries feeding a tumor while simultaneously blocking those arteries with tiny particles. This one-two punch concentrates the drug at the tumor site and starves the growth of its blood supply. It’s a standard treatment for liver cancers that can’t be surgically removed.
Radioembolization takes a similar approach but uses millions of tiny radioactive beads instead of chemotherapy. These microspheres, loaded with a radioactive element called yttrium-90, are injected through a catheter into the liver’s blood supply. The beads lodge in and around the tumor, delivering high-dose radiation directly to cancer cells while largely sparing healthy tissue. The radiation decays by half every 64 hours, so the treatment effect is concentrated in a short window. This technique has shown a safer side-effect profile than chemoembolization, with longer periods before tumors progress, and can sometimes shrink tumors enough to make patients eligible for a liver transplant.
Biopsies and Drainage
Image-guided biopsy is one of the most frequently performed IR procedures. Using ultrasound or CT to visualize the target in real time, the radiologist inserts a needle through the skin to collect a tissue sample from a suspicious mass. This works for nearly any organ: liver, lung, kidney, lymph nodes, bone. It replaces what would otherwise require a surgical incision and general anesthesia.
Abscess drainage follows a similar principle. When an infection forms a pocket of fluid or pus deep inside the body, IR can place a drainage catheter directly into the collection. For large, superficial abscesses, the catheter and a sharp stylet are placed in a single step. For small, deep abscesses, a more precise multi-step technique is used: a thin needle punctures the collection first, a guidewire is threaded through, and then a drainage catheter slides over the wire into position. Ultrasound works well for abscesses near the liver or spleen, while CT guidance is better for hard-to-see locations like the deep pelvis, areas near the spine, or the lungs. Fluid samples are typically sent for lab analysis to identify the bacteria involved.
Uterine Fibroid Embolization
Uterine fibroid embolization (UFE) is a standout IR procedure for women dealing with fibroids that cause heavy menstrual bleeding, pelvic pain, frequent urination from bladder pressure, constipation, pain during sex, or an enlarged uterus. A catheter is threaded into the uterine arteries, and tiny particles are injected to block blood flow to the fibroids. Without their blood supply, the fibroids gradually shrink.
UFE preserves the uterus, which matters for women who want to avoid a hysterectomy. Recovery typically involves a follow-up ultrasound or MRI around six months after the procedure to assess how much the fibroids have shrunk. A similar technique, prostate artery embolization, uses the same concept to reduce an enlarged prostate in men experiencing urinary symptoms.
Spine Procedures for Pain Relief
Vertebroplasty and kyphoplasty treat vertebral compression fractures, which are common in people with osteoporosis or cancer that has spread to the spine. Both are performed through a needle inserted into the fractured vertebra under image guidance.
In vertebroplasty, bone cement is injected directly into the fractured vertebra to stabilize it. Kyphoplasty adds an extra step: a small balloon is inflated inside the vertebra first to restore some of the lost height before the cement fills the space. Acute fractures (one to three weeks old) respond best to kyphoplasty’s height restoration because the bone hasn’t yet healed in its collapsed position. Both procedures provide significant pain relief, likely by stabilizing tiny fractures within the bone and reducing the mechanical forces that cause pain. In cancer patients, these procedures are sometimes combined with radiofrequency ablation to reduce the tumor within the vertebra before injecting cement.
How Catheter Access Works
Most catheter-based IR procedures require an entry point into the vascular system. The two primary options are the femoral artery in the groin and the radial artery in the wrist. The femoral approach has been the traditional standard because it accommodates larger devices and gives the operator excellent catheter control. However, the groin site carries a higher risk of bleeding complications and requires patients to lie flat with their leg immobilized for several hours afterward.
The wrist (radial) approach has gained significant ground as an alternative. Because the radial artery sits close to the skin’s surface and is easily compressed, bleeding complications are virtually eliminated. Patients can sit up and walk immediately after the procedure, and hospital stays are noticeably shorter. The tradeoff is that the smaller artery limits the size of instruments that can be used, so the femoral approach remains necessary for procedures requiring larger catheters or devices.
What the Experience Looks Like
Most IR procedures are performed under moderate sedation or local anesthesia rather than general anesthesia, though this varies by complexity. You’ll typically be asked to fast beforehand. During the procedure, you may need to hold your breath briefly at certain points while imaging is being captured.
Recovery depends heavily on which procedure you had and where the catheter was inserted. Procedures using groin access often require several hours of lying still with the leg immobilized to let the puncture site seal. Wrist-access procedures allow you to move around much sooner. For procedures like tumor ablation or embolization, expect some soreness or fatigue in the days that follow. Many IR procedures are done on an outpatient basis or with just an overnight hospital stay, compared to the days or weeks of recovery that open surgery for the same condition might require.
Risks and Complications
IR procedures are generally safer than their open surgical alternatives, but they aren’t risk-free. Complications at the arterial access site (bleeding, bruising, or vessel damage) occur in up to 6% of patients undergoing procedures through the groin. Drainage procedures carry complication rates as high as 10%. Research suggests that 55 to 84% of adverse events in IR are preventable and frequently involve device-related issues like improper use or malfunction, which underscores the importance of having an experienced team.
The risk-benefit calculation depends on the specific procedure and the patient’s condition. For some situations, IR is clearly the lower-risk option. For others, the comparison is more nuanced. Percutaneous gallbladder drainage in patients with acute gallbladder inflammation, for example, has shown 30-day readmission rates as high as 42% and carries roughly three times the mortality risk compared to emergency laparoscopic surgery, making it a procedure reserved for patients too sick to tolerate an operation.
Robotic-Assisted IR
The newest frontier in interventional radiology involves robotic systems that help guide catheters through blood vessels. Current commercial platforms offer partial autonomy, handling predictable portions of the procedure while the physician maintains control for complex navigation. Some systems now include haptic force feedback, letting the operator “feel” the resistance of the catheter tip through a remote controller.
Researchers are also developing MRI-compatible robotic platforms that could eliminate radiation exposure during procedures entirely, replacing traditional X-ray guidance with real-time 3D MRI images. Artificial intelligence is being integrated to assist with navigation planning and decision-making, though fully autonomous catheter procedures remain a research goal rather than a clinical reality.