Angiography Machines

History of Angiography Machines in Hospitals

Early History (1920s-1950s)

Angiography, the imaging of blood vessels using contrast agents, was first developed in the 1920s. In 1927, Portuguese physician Egas Moniz performed the first cerebral angiogram, marking the beginning of the field. Early angiography was rudimentary, involving direct injection of contrast media into blood vessels followed by simple X-ray imaging.

The Emergence of Fluoroscopy (1950s-1970s)

With the advent of fluoroscopy (real-time X-ray imaging) in the 1950s, angiography became more sophisticated. Physicians could now visualize the contrast agent moving through blood vessels in real-time, allowing for more precise diagnosis and better understanding of vascular anatomy. During this period, selective angiography—injecting contrast media into specific vessels using catheters—became common practice.

Digital Subtraction Angiography (DSA) and Modern Systems (1980s-Present)

In the late 1970s and early 1980s, Digital Subtraction Angiography (DSA) revolutionized angiography by allowing digital enhancement of images, subtracting the background and improving the clarity of blood vessels. This technique enabled detailed imaging of vessels with reduced contrast agent use and radiation exposure.
From the 1990s onward, angiography machines became increasingly sophisticated, incorporating more advanced C-arms (the part of the machine that holds the X-ray detector and source), better imaging resolution, and integration with computed tomography (CT) and magnetic resonance imaging (MRI) systems. Today’s angiography machines are highly integrated systems with 3D imaging, real-time navigation, and interventional capabilities.

How Angiography Machines Work

Angiography machines use X-ray imaging to visualize blood vessels after a contrast agent is injected into the bloodstream. The contrast agent makes the blood vessels visible on the X-ray, allowing clinicians to diagnose and treat various conditions such as blockages, aneurysms, and malformations in the arteries and veins.

Basic Principles:

1. Contrast Agent Injection: A contrast agent (usually iodine-based) is injected into the bloodstream via a catheter that is guided to the vessel of interest.
2. X-ray Imaging: X-rays pass through the body, and the contrast agent absorbs these rays, making blood vessels visible on the X-ray image.
3. Fluoroscopy and Real-Time Imaging: Fluoroscopy allows real-time imaging of the blood flow through vessels, helping guide interventions like stent placements or embolizations.
4. Digital Subtraction: DSA enhances image clarity by subtracting pre-contrast images from post-contrast images, removing background structures like bones and tissues, and highlighting blood vessels.

Components of an Angiography System

1. X-ray Generator and Tube:

• X-ray Tube: Produces X-rays that pass through the patient’s body. The X-ray tube is usually mounted on a C-arm or gantry that rotates around the patient to capture images from different angles.
• X-ray Generator: Powers the X-ray tube and controls the intensity and duration of the X-rays.

1. C-arm or Gantry:

• The C-arm holds both the X-ray source and detector and allows for flexible movement around the patient. It provides a wide range of imaging angles and is crucial for creating detailed 3D reconstructions.

1. Digital Detectors:

• Flat-panel Detectors (FPDs): Capture the X-rays after they pass through the patient and convert them into digital images. FPDs are preferred over older image intensifiers due to their superior image quality and lower radiation doses.

1. Patient Table:

• A motorized, radiolucent table that can be adjusted in height and position to help with patient positioning and comfort during the procedure. It is designed to be X-ray transparent to avoid interference with imaging.

1. Contrast Injector:

• Automated Injectors deliver contrast media into the bloodstream at controlled rates. The injector is synchronized with imaging to ensure the contrast reaches the target area when the images are captured.

1. Fluoroscopy Console:

• The control panel where the operator adjusts imaging parameters such as exposure time, radiation dose, and frame rate. It also displays real-time images from fluoroscopy during the procedure.

1. Image Processing Workstation:

• After images are captured, the processing workstation is used to enhance, manipulate, and analyze images. In DSA, the workstation is responsible for subtracting pre-contrast images from post-contrast images to produce clear angiographic visuals.

1. Radiation Shielding and Safety Equipment:

• Lead shielding, protective barriers, and radiation monitoring devices are essential to protect both patients and staff from excess radiation exposure.

Variations of Angiography Machines

1. Single-Plane Systems:

• These systems have a single C-arm that captures images in one plane at a time. They are typically used for less complex procedures or diagnostic angiography.

1. Biplane Angiography Systems:

• These advanced systems have two C-arms that can capture images simultaneously from two different angles. They are commonly used in more complex neurovascular or cardiac interventions, where imaging from multiple perspectives is critical.

1. Hybrid Operating Rooms:

• In these setups, an angiography machine is integrated with other imaging technologies (such as CT or MRI) in the operating room, allowing surgeons to perform both diagnostics and interventions within the same room, improving efficiency and patient safety.

1. Portable Angiography Systems:

• These smaller, mobile systems are designed for use in emergency or bedside situations. Though they offer less image quality and fewer features compared to stationary units, they are useful in urgent settings.

1. Rotational Angiography:

• In some advanced systems, the C-arm rotates around the patient to create 3D images of the vasculature. This is particularly useful for complex vascular structures such as cerebral arteries or coronary vessels.

Clinical Uses of Angiography Machines

Angiography is widely used for diagnostic and interventional procedures in various medical specialties, including cardiology, neurology, and vascular surgery.

1. Coronary Angiography (Cardiology):

• Used to diagnose and treat coronary artery disease by visualizing blockages in coronary arteries. Interventional procedures, such as stent placement and angioplasty, are often performed during the same session.

1. Neurovascular Angiography (Neurology):

• Used to diagnose and treat conditions like aneurysms, arteriovenous malformations (AVMs), and strokes. Neurointerventionalists use biplane angiography systems to perform procedures like coiling for aneurysms or thrombectomy for stroke patients.

1. Peripheral Angiography (Vascular Surgery):

• Used to image blood vessels in the limbs, kidneys, and other peripheral regions to diagnose blockages or malformations. Angioplasty or stent placement can be performed to treat peripheral artery disease (PAD).

1. Pulmonary Angiography (Pulmonology):

• Used to detect pulmonary embolism (blockages in the pulmonary arteries) and other abnormalities in the lung’s vasculature.

1. Interventional Oncology:

• In oncology, angiography can be used for procedures like chemoembolization or radioembolization, where chemotherapy or radiation is delivered directly to a tumor via the blood vessels.

1. Aortic Angiography (Cardiothoracic Surgery):

• Used to diagnose and treat aortic aneurysms or dissections. Endovascular aortic repair (EVAR) is a common interventional procedure performed under angiographic guidance.

Daily User Checks for Angiography Machines

1. Power Supply Check:

• Verify that the system is connected to a stable power source and that backup power systems (e.g., uninterruptible power supply, or UPS) are functional.

1. Calibration:

• Check the calibration of the X-ray generator and detectors to ensure optimal image quality and accurate dosing of radiation.

1. Contrast Injector Test:

• Perform a test run of the contrast injector to ensure proper functioning, appropriate flow rates, and timing synchronization with the imaging system.

1. C-arm Movement Check:

• Test the movement of the C-arm or gantry to ensure smooth, precise positioning.

1. Monitor Alarms:

• Ensure that all system alarms and alerts (e.g., for radiation dose, injector issues, or mechanical problems) are functioning correctly.

1. Image Quality Test:

• Capture test images to ensure the system is producing high-quality, clear images with the correct exposure settings.

1. Patient Table Check:

• Confirm that the patient table is working correctly, with smooth height adjustments and proper positioning controls.

Preventative Maintenance Requirements

1. Regular Cleaning:

• Clean all external components, especially the X-ray tube, flat-panel detector, and C-arm, to prevent dust buildup, which can degrade image quality.

1. System Calibration:

• Periodically calibrate the system, especially the X-ray generator and detectors, to maintain accuracy in radiation dosing and image clarity.

1. Software Updates:

• Ensure that the system software is up to date to enhance functionality, improve image processing, and fix any known software bugs.

1. Contrast Injector Maintenance:

• Perform regular maintenance on the contrast injector, including replacing any worn-out parts and ensuring that the system operates smoothly.

1. X-ray Tube and Detector Inspection:

• Regularly inspect the X-ray tube for signs of wear and tear. Over time, the X-ray tube may need replacement as its efficiency declines.

1. Radiation Shielding Checks:

• Inspect lead shielding and protective barriers to ensure they are functioning correctly and there are no leaks that could expose staff or patients to unnecessary radiation.

Common Troubleshooting Steps

1. Image Quality Issues:

• Check for dust or debris on the flat-panel detector or C-arm.
• Recalibrate the system if the images are blurry or show artifacts.
• Verify proper contrast agent administration and injector timing.

1. C-arm Malfunction:

• If the C-arm does not move smoothly, check for mechanical obstructions or calibration errors. Rebooting the system may resolve movement issues.

1. Contrast Injector Failure:

• Ensure proper connection of the contrast injector. Check if the contrast agent is flowing freely and the injector settings are correct.

1. System Overheating:

• Ensure the cooling system (if applicable) is functioning. Check for adequate airflow around the X-ray generator and other heat-producing components.

1. Power Supply Issues:

• If the machine shuts down unexpectedly, check the power supply connections and backup systems.

Manufacturers of Angiography Machines

1. Siemens Healthineers: Known for their high-end Artis series, Siemens offers advanced features like 3D imaging, biplane systems, and rotational angiography.
2. GE Healthcare: GE’s Innova series provides reliable single-plane and biplane angiography systems, often used in both diagnostic and interventional settings.
3. Philips Healthcare: Philips’ Azurion and Allura series are widely used, known for their image quality, low radiation doses, and integration with other imaging systems.
4. Canon Medical Systems: Canon provides systems like the Alphenix series, known for their versatility in interventional radiology and cardiology.
5. Shimadzu: Specializes in both single-plane and biplane angiography systems, offering the Trinias series with advanced features for neurovascular and cardiac imaging.

Typical Cost and Lifespan

• Cost:
• Single-plane angiography machines typically cost between $500,000 to $1.5 million, depending on features and capabilities.
• Biplane systems, which are more complex, range from $1.5 million to $3 million or more.
• Lifespan:
• The average lifespan of an angiography machine is around 10-15 years. With proper maintenance and periodic upgrades, systems can last longer, but frequent use may shorten their operational life.