Cath Labs, Angiography Suites, and EP Labs

A medical equipment planner usually finds the more complex areas of the hospital the most interesting to plan.

These 3 rooms are some of the most equipment intensive and expensive areas within a hospital. All 3 rooms are using similar imaging equipment, however the specifics of what these diagnostic studies are used for vary slightly.

In a catheterization laboratory (Or Cath Lab) the emphasis is on the heart and the blood vessels delivering oxygen to the heart muscle. The images generated by the study will allow doctors to visualize if there are any problems in the hearts ability to pump blood or restrictions in the ability to deliver blood to the heart muscle. Here is a brief video explaining the Catheterization procedure:




In an Angiography Suite (Also called Special Procedures or Angio Lab) the focus expands to other parts of the circulatory system. The legs, arms, neck and head are imaged to determine if there are blocked or compromised blood vessels. A corrective procedure, called an angioplasty, can be done to repair a blocked or narrowed vessel. The differences in designing a Cath Lab or an Angio lab are minimal from an architectural perspective. The Cath Lab is focused specifically on the heart, so the patient will be situated on the table with the imaging device focused on the center of the chest. In an Angio suite, the study may be on an arm, leg, or other area of the body, so the imaging table may be extended to allow the part of the body to be underneath the imaging device. It is this "travel" of the imaging table that requires an Angio Suite to have greater freedom of movement. Of critical importance is designing the room to allow full articulation of the imaging table. In an angio suite, the table may be extended and rotated on an angle to best position the patient.

Here is a video of a patients upper right-side. (Imagine the position a patient would have been be in to accommodate this image.)



Another difference between traditional Cath Labs and Angio Suites is the size of the imaging head - called an image intensifier. This is simply the diameter of the video image. Typical sizes of the image intensifier are in 1 inch increments from 7 inches to 16 inches. The smaller sizes are common for Cath Labs, while the larger sizes are common for Angio Labs. While this may seem counter-intuitive (You might think the heart would have the larger view and the arteries a smaller view) the heart has a very defined location and size, so the smaller image-intensifier is adequate. In an Angio procedure, the additional diameter of view allows for the clinicians to view other structures around the suspect vessels. Essentially, it is the ability to see the forest, not just the tree.

Finally there is the EP Lab or Electro-physiology lab. These rooms are specialized in analyzing the electrical signals controlling the heart. When a patient has issues with a fast,slow, or irregular heart rate, the cause may be with the electrical signals being sent to the heart. The EP lab uses sophisticated monitoring equipment to trace and record the path of the electrical signal and allows the clinician to recommend corrective action. These corrective actions may include invasive procedures, such as implanting a pace maker or ablation therapy. Here is a video offering an overview of how electrical signals control the heart. This particular video references using an EKG, not an EP lab, but the explanation of the physiology of the process is excellent.



Here are photos of each type of room. You will find them to be almost identical in view. A large C-arm shaped x-ray device, an imaging table, and several ceiling mounted monitors to allow the clinicians to view the live video, archived, and other reference images.

Cath Lab





Angio Lab





EP Lab




In addition, CT Scanners are being widely used for angio procedures. The broad functionality of CT scanners allows them to deliver a wide variety of images, helping facilities achieve a greater return on investment. Single-function devices, such as a Cath lab or Angio suite require a return-on-investment to justify the cost to purchase and operate. (1 million is the minimum cost to equip a room). Manufacturers will continue to try and expand the range of applications their devices can provide as healthcare providers are tasked with creating greater value for their dollar. CT, MRI and possibly other modalities will continue to be offered as alternatives. Cath/Angio Suite are also common, allowing the same room to be used for both types procedures.

Utilizing your medical equipment planner

Are you working with a medical equipment planner on your project? If so, they can be a valuable resource early in the design process. Too often the equipment planners are relied upon to furnish an equipment report and cutsheets in DD's or CD's, but little in the earlier SD phase.

If you are a "form follows function" person like me, it makes sense to understand what impact the medical equipment may have on the rooms before designing them. The medical equipment technology evolves very rapidly, so your equipment planner may offer insights to help you design a better work flow for both rooms and departments.

When working on projects in the early 1990's the shift from "wet" processing to "dry" processing of x-ray film had a huge impact on facility design. One project in particular had designed a centralized silver recovery system. The architect and engineers had all of the used developer and fixer from 8 darkrooms draining into a centralized holding tank for silver recovery and disposal. It was something that would have served their existing facility very well. However, this system was going to have no benefit to the new facility within a year or two after opening.

The cost of the waste distribution system was to be paid for by the anticipated economies of scale and recouped cost from silver recovery. Unfortunately, these economies were simply never going to be reached. The dry processing technology was well on its way to making both darkrooms and silver-based processing chemicals obsolete. While the project would open its doors with traditional wet processing, these systems were to be replaced very soon afterward.

The centralized system was value-engineered out of the design during CD"s, but a discussion with the equipment planner a few month earlier would have saved thousands of dollars in design fees.

What new trends and technologies might influence your next project?

Patients are getting larger. Bariatric beds require larger door widths, allowing them to be moved in and out of patient rooms. The rising use of ceiling mounted patient lifts is reducing back injuries to staff, but also requires structural support to accommodate both the lift unit and the patient. The heavier the patient, the greater the structural support required. Will your ceilings support 700 pounds? Does it make sense to designate rooms as "future" bariatric rooms and install the structural support in the ceilings now?

PACs is getting more prevalent. Fewer hard copy films mean less need for film archives space. PACs viewers are replacing x-ray view boxes. Requirements for shelving units, carts, and racks to accommodate 11X17 film are greatly reduced in most facilities. Don't just emulate existing space and designs for x-ray film. Develop an understanding of how the facility will digitize hard copy films that are pulled from archives or that accompany a referred patient. The design of customized casework to accommodate these over-sized x-ray film jackets is a waste of time and money in todays environment.

How might your project be affected by the next leap in technology? Ask your medical equipment planning consultant for a list of medical trends and their potential impact on each department. It's a great exercise for educating your project design team and will also help to engage your equipment planner earlier in the project.

Planning Imaging Areas (Non X-Ray)

If my experiences are representative of most medical equipment planners, the design team members who are unfamiliar with all of the imaging modalities may assume that every imaging device uses X-rays. The need to provide shielding for the imaging rooms, even the ones that do not employ x-rays, only reinforces this mistaken belief.

There are in fact several imaging modalities that do NOT use X-rays. MRI uses a combination of magnetic field and radio-frequency waves to create an image; An ultrasound unit uses sound waves; and several devices under the umbrella of "Nuclear Medicine" utilize radioisotopes to create images of the internal structures of the body.

Nuclear Medicine: These machines generate images by detecting the emittance of radioisotopes that have been given to a patient. These radioisotopes can be injected directly, via an IV, or they may be inhaled or ingested. These devices include:
Gamma Camera (Single, Dual or Triple Head)
PET Scanner (Positron Emission Tomography)
SPECT (Single Positron Emission Computed Tomography)

The rest of this blog entry will focus on nuclear medicine imaging. If you are interested in learning more about MRI or Ultrasound, follow these links:
MRI (Magnetic Resonance Imaging) See blog entry for MRI
Ultrasound See blog entry for Ultrasound


Each of these modalities are what I would call "passive" or "listening" devices. They create an image by detecting the signals or activity emitted within the patients body. (MRI and Ultrasound units are covered in greater depth within their respective posts in this blog.) The Nuclear Medicine modalities mentioned above rely upon the rapid decay of radioisotopes to emit energy, which these devices capture to generate an image.

So while an x-ray device will generate x-rays to pass through the body to create the image, these "passive" devices are highly efficient listening devices that detect and capture the activities occurring inside of the body. You could spend a week lying on the table of a gamma camera and it would have no effect on you. So if you were a fan of "The Incredible Hulk" growing up (or still are), you will be relieved to know that undergoing a nuclear medicine test in a gamma camera has zero risk of turning you green or morphing your into a Mr. Universe contestant. It can however affect your mood.

Patient anxiety is common among those undergoing tests for a variety of reasons:
1. They are having a medical test in a hospital.
2. The equipment is large, imposing, and looks similar to that thing that turned Bill Bixby into The Incredible Hulk.
3. The sign on the door has a big "Radiation" symbol on it.

These rooms require radiation shielding to prevent the clinicians, technicians, and other staff from being exposed to the cumulative effects of these low-dose radiation exposures. The patient will either ingest, inhale, or be injected with a radioactive isotope. (The individual dosage level is not dangerous) The room shielding simply addresses the need to shield others from the cumulative effect of repeated exposures. For a nuclear medicine tech, they may see 5-8 patients per day, 5 days per week. So they have the potential for exposure at levels 100 times what a patient receives in their single study. Patients carry the radioisotope in their blood stream, which then exits the patients body via breath or through the skin. As it disperses, the tech and any others in the room will be exposed to trace amounts of radiation. The room shielding simply "holds" these low levels of radiation in the room until its energy is dispersed. Each of these radioisotopes lose their radioactive properties very rapidly.

Most of the radiation exposure that a technician is exposed to is in the "Hot Lab" where the actual dosage of the radioisotope to be given to the patient it prepared. This room has lead-lined cabinets for storage of the radioisotopes, and for disposal of any left-over material in the syringe.

Here are photos of the devices mentioned above:
Positron Emission Tomograpghy (PET)


SPECT Camera


Upright SPECT (Specialized for cardiac studies)


Gamma Camera (Single Head)


Gamma Camera (triple head)


A note about the number of heads on a Gamma Camera:
The number of heads on a gamma camera influences the speed of the image acquisition process. The camera head(s) rotate around the patient, capturing data to create the image. A single head camera must make a 360 degree rotation while a 2-head camera must rotate 180 degrees and a 3-head camera only 120 degrees to capture the same amount of information.

There are also hybrid units that will be discussed in later blogs:
SPECT/CT (SPECT Camera and CT Scanner)
PET/CT (Positron Emission Tomography and CT Scanner)

For each of these imaging modalities, the actual source of the radiation is the radioisotope, not the equipment itself. There are several radioisotopes that are comonly used, each having a specific property that makes it uniquely suited for various studies. The purpose of this blog is to understand the basics of room planning criteria, not the actual science behind how radioisotopes work. If you are interested in learning more about radioisotopes and their uses, visit Wikipedia.

Of great importance to the planner should be an understanding the movement of these radioisotopes through the facility. Some hospitals and clinics have an outside service deliver them on a just-in-time delivery schedule. Others have a cyclotron to manufacturer them on-site. It is important to understand the deliver method and ensure that adequate security, storage and containment is available at every step of the process. A later blog post called "Planning for cyclotrons and radioisotopes" will be dedicated to this subject.

Planning Imaging Areas (X-Ray Units Part II)

Each x-ray device has a unique niche that it fills. Some are specific to imaging a body part, others are used for specific types of studies, and some are generic enough to be used in multiple different situations. It is helpful for anyone working with a medical equipment planner or providing medical equipment planning services to have a good understanding of each. Here is a sampling:

Mammography - Used to x-ray the breast, most often to screen for breast cancer.


Chest Unit - Used to image the chest area ideal for lungs, heart, liver, etc.


General Rad - Used to image the skeletal system (Bones & joints)


Mobile X-Ray Unit - Used for a variety of extremity and chest imaging needs at the patient bedside.


Portable C-arm - Creates a fluoroscopic image.


Flouroscopy (R&F Unit)- Creates a "Live Motion" image using a phosphor plate and an image intensifier to create a video.


CT Scanner - Used to image in 3D by creating "slices". The X-ray tube rotates around the patient and takes multiple x-rays, that are then re-created as a 3D image.


See a video of the internal workings of a CT scanner:

Podiatry - Used to image the foot


Dental - Used to image teeth and jaw


Angio/Cath/EP - These rooms are highly specialized for imaging the heart and vascular system.


Adding the term "digital" to any of these devices simply means that rather than use an x-ray film cassette, the system uses a digital imaging device. Much like traditional film has been largely replaced by digital cameras, the speed and expanded functionality of digital x-ray is changing the way departments are run. You will still find some radiologists who swear by film as a superior method, especially as it relates to mammography, where the subtlety of the image colors can be critical to detection. A quick explanation of why they feel this way may be helpful.

A traditional x-ray film is gathered as x-rays pass through body and strike the x-ray film surface on the other side of the body. It is the "actual" image created by the x-ray. In digital, a conversion process occurs. The x-rays that strike the surface of the digital receptor are converted into a signal that is transferred to a computer screen. It is essentially a series of dots that are each assigned a location in an x/y grid. The concern about digital imaging has been that very subtle variations may not be as clear in a digital image as in a traditional film. There is a a similar argument over the quality of CD's compared to the original pressed vinyl recordings of artists.

The technology has progressed greatly in the past few years, but there are still some who challenge the superiority of digital over film. There is no question that efficiency and lower costs are achieved by using digital imaging techniques to produce and share images among doctors and hospitals.

Planning Imaging Areas (X-Ray Units Part I)

In looking at how to best parse the various imaging modalities: MRI, Nuclear medicine, Ultrasound, etc. I have decided to simply lump all of the x-ray units into one long blog entry. I think doing it this way will accomplish two things: First, it will help make a clear differentiation between x-ray and non-x-ray imaging technologies, and second, it will help to show the variations in x-ray devices. While somewhat remedial for a clinician, a medical equipment planning project will often include team members who are not as well versed in these nuances. The role of a medical equipment planner is to educate the entire design team to the technologies being used. This helps to elevate the overall level of medical planning knowledge.

An x-ray is an x-ray. But there are various types of x-ray units to address different needs. These can be broken into 2 basic groups:

1) Body part(s) to be imaged
2) Portability

When the patient can come to the x-ray unit, the x-ray device and room can be specialized to the type of study or body part. Teeth, Jaw, breast, foot, chest, etc. If the unit comes to the patient, the x-ray unit is more universal: Portable X-ray unit or Mobile C-arm. There are in fact 2 sizes of C-arm, the smaller of the 2 (Mini C-arm) typically used to image limbs (hands, wrists, feet, etc).

Specialty clinics will typically have dedicated rooms and task-specific x-ray units:
Dental office > Dental x-ray unit (Teeth)
Podiatry office > Podiatry x-ray unit (Foot)
Womens Clinic > Mammography X-ray Unit (Breast)
Cardiology Department > Cath Lab (Heart)

The more generic a department patient population, the more universal the x-ray device:
Emergency Departments and Imaging Departments usually share access to multiple imaging rooms:
General Radiographic - Skeletal system
General Rad/Tomography - 3D views of skeletal system
R&F (Radiographic/Fluoroscopic) - Video images and clips of internal structures
CT (Computed Tomography) - 3D images of structures

In addition, the ER usually has access to a portable X-ray and Mobile C-arm when the patient cannot be easily moved, or time is of the essence. More on these distinctions in later blogs...

X-rays are a form of radiation and therefore require the room to be shielded. Lead is the most common form of shielding, due mostly to its density. Using concrete or other shielding substance will greatly increase the thickness of the walls and complicate the design of surrounding rooms. The greater the throughput of the the x-ray device, the greater the cumulative amount of radiation produced. When a patient is having an x-ray, the amount of radiation given at at a single sitting is not dangerous. It is the cumulative exposure over time that is dangerous. Each of us can go in for dental x-rays, a routine chest x-ray, or a visit to the ER if we sprain or break something. These infrequent exposures represent no health risk to us.

The rooms are shielded for the protection of those who work in the vicinity of the room. The offices, exam rooms, conference rooms and staff work areas.

A patient may receive a series x-rays (Usually 1 - 8, but can be more) in a single sitting. The x-ray tech may see 3 - 4 patients per hour over an 8 hour shift. So that would be over 200 exposures per day. Without the lead shielding, the clerk who sits at the desk on the adjacent wall or the family members sitting in the waiting room across the hall would be exposed to these very large cumulative doses. So we are shielding the people who are working, visiting or being cared for in the adjacent areas.

Radiation scatters, so think not only about the 4 walls, but also the floor and ceiling. A licensed physicist will calculate the amount of shielding required, but typically every x-ray room can be shielded with a simple 1/8 inch leaded sheet rock. The critical factor is the installation. Joints, corners, and punch outs need to be installed correctly to avoid any leakage.

The source of all x-rays is an x-ray tube. The tube is housed in an articulating arm, (wall, table or ceiling mounted) or within the unit itself. The other components of an X-ray unit have a specific purpose related to: patient positioning, power generation, or image acquisition.

Patient positioning. X-rays produce images because they pass through bone, tissue and fluid at different rates. Dense structures appear in white and less dense appears in black on the image. The goal of patient positioning is to make the x-rays pass through the patient in a path that will have the least interference to the structure the radiologist wants to view. If you have ever shifted, moved, or repositioned yourself to get a better view of something, you have been "positioning". So standing, laying down, sitting, or otherwise being contorted into the "ideal" position to yield the best image of a bone, organ or structure the radiologist wants to read. The table is the most basic positioning device. These can tilt up, side to side and telescope to allow the technician to move a patient into the ideal position. This articulation requires ample room.

When a design team takes a "department tour" you typically see an imaging table in its flat position. Here is a unit articulated up to a 90 degree position:



Think of a swiss army knife in your pocket. Then think of it with every blade and tool extended. The x-ray room needs to accommodate the table in all of its various extensions. So when you do a walking tour of the department and see the table in its "closed" position, you may not get a sense of the space it needs to move around within. I find that 1 in 5 departments I have visited had at least 1 room with a conflict between the range of motion of the imaging table and 1 of the walls or cabinets.

Power Generation. X-ray tubes require a lot of energy. Most will require a dedicated 480v feed into the power cabinet. From there, the vendors equipment usually steps down the power required for the various other system components - electronics, table, x-ray tube, control panel, etc. There may be floor trenches, wall ducting and cable trays to distribute the power and data lines. Every vendor is a little bit different, so a vendor site-specific drawing is critical to ensure your room is adequately sized and designed. The problem is that technology evolves so quickly and manufacturers have a tendency to leap frog one another every year or so, it is difficult for an administrator or department head to commit to the exact manufacturer and model more than just a few months in advance. This typically leaves the design team and contractor with a dilemma. How to complete the room on schedule. The best alternative I have found is to skip the room until the PO for the X-ray unit is issued. Yes, pouring the floor, working in the ceiling, and hanging leaded dry wall will add some punch list items to your project. But, it will be cheaper than tearing out walls, ceiling and cutting/breaking out new troughs.

Image acquisition. Image acquisition is simply the process of capturing an x-ray image. Traditionally, a film cassette is placed behind the patient. The X-ray tube generates a burst of x-rays that pass through the patient and into the x-ray film cassette. The x-ray film captures the image. The film cassette is placed in a "bucky" or simply leaned up against the patient. A bucky is a device that holds the x-ray film cassette. Today, there are digital x-ray units that have almost eliminated the need for film. The x-ray image is captured digitally in a receptor and processed directly into an image (DR or Direct Radiography) or the image is captured on a phosphorous plate that is read in a "Plate Reader". Think of a phosphor plate as a high-tech "Etch-a-sketch".

The plate reader converts the image into digital format, then clears the phosphor plate. These plates are re-used many times before needing to be replaced.

Here is a wall bucky:


Here is a plate reader:


Here is a laser imager:


The plate readers and laser imagers are now an integral part of the image acquisition process. Fewer and fewer "wet processing" systems are in use. "Wet processing" is the catch-all term for traditional x-ray film processing that involves the use of chemicals (developer & fixer) and film processors in a dark room.

No less important in all of this is the image viewer. The image viewer is a high definition computer monitor. It displays the x-ray image and allows the operator to zoom, edit and make adjustments to make the image much easier to view. These have taken the place of x-ray view boxes (Illuminators), which were used to view hard copy x-rays.

Here is a PACs Viewer (Top) and PACS reading station (Bottom):

Planning Ultrasound Rooms

Ultrasound is a diagnostic tool that has evolved greatly in the past 5 years. The systems have branched into 2 primary types: Abdominal and Vascular. The same units can accomplish either procedure, however different software and probes are used. The most common procedure is the fetal ultrasound, used to visualize the fetus of a pregnant mother.

Medical equipment planners can help design a space but offering the design team insight into the use and function of the technology.

I will start with a review of the abdominal ultrasound:

The ultrasound unit is roughly 3/4 the height of a domestic refrigerator and about the same width and depth. There are also very small hand-held units available, but the traditional sized machines are still the primary workhorse in both hospital and outpatient settings. The features and capabilities have grown more robust in a number of ways. The range of options now includes 2D, 3D, and 4D visualization software. There are various probes (The scanning instrument that is tethered to the unit) are also more varied, with each probe "tuned" to scan different body parts and organs.

Here is a video offering some perspective on the use and 2D, 3D and 4D ultrasound.



In addition to fetal ultrasound, the liver, kidneys, and other abdominal structures can be imaged.

With all of these technological enhancements, the requirements for the room itself have remained largely unchanged.

A room that is dedicated to abdominal ultrasound should have the following:
1. An easily darkened room. Any exterior windows should have curtains or blinds capable of being drawn. The room lighting should be on dimmers or switched to allow the lighting to be reduced by at least 70% or more. This allows the monitor to be more easily viewed by both the ultrasound technician and the others.

2. Easy access to a bathroom. For fetal ultrasounds, the patient (Pregnant mom) is asked to drink about 1 litre of water prior to the ultrasound. This fills the bladder and helps to produce a sharper image. The patient is asked to "hold it" for the ultrasound, but will want to use the bathroom almost immediately afterward.

3. Room for family members. Ultrasound is a diagnostic test that produces no x-rays and uses no contrast agents, so a family member can easily accompany the patient into the exam room. An exam table or stretcher is usually placed in the center of the room. While this allows 360 degree access around the patient, the primary reason for this configuration is it allows the ultrasound unit and operator to occupy the space to the right-side of the patient and the left side is available for a family member to stand and view the ultrasound. It also allows easy access for the patient.

4. A remote video monitor placement. The monitor on the ultrasound unit is for the ultrasound technician to use. It may be in a bad location to be viewed by the patient or the family members. A hard copy image is usually printed for the patient to take with them, but it is preferred to allow the others in the room to have easy viewing access. A ceiling or wall mounted video monitor will allow easy viewing and avoid any issues with the patient moving around to view the image or any family member leaning into the technician's "comfort space" to get a closer look.

Vascular Ultrasound:
Physically there is very little difference about an ultrasound unit used for vascular procedures. A vascular ultrasound will look at the structure and blood flow within the heart, the specific valves and chambers of the heart, as well as the veins and arteries that make up the circulatory system. Common ultrasound procedures include the neck, leg and heart. An ultrasound study of the heart is called an echo cardiogram. These are often done using what is called a "stress" test.

The stress test simply refers to elevating the patients heart rate prior of the study. There are two types of stress test: An exercise stress (The patient walks on a treadmill or up and down a small fight of stairs) or a Pharma stress (The patient is given an injection that increases their heart rate.) The pharma stress is used if the patient is physically unable to walk or exercises to increase their heart rate.

In the exercise stress test, the patient immediately moves from the treadmill to a stretcher and lay's down. The technician will conduct the echo (ultrasound) while the heart rate is still elevated to determine if the heart is pumping blood efficiently. The layout of the room is important as the room needs to accommodate the patient, the technician, the ultrasound unit, stretcher, treadmill and EKG unit. This makes for a crowded room! The patient is tethered to the EKG unit with leads that are connected to the EKG machine as they are walking on the treadmill. After reaching the desired heart rate, the patient needs a clear path to the stretcher to lay down.

The room design for a vascular study can ignore the need for bathroom access mentioned in the fetal ultrasound section. The patient is not required to drink water for these procedures. However the space requirements within the room are greater.

Here is a video of what an ultrasound unit looks like. Nothing too interesting about it, but you will see if from variety of angles and perspectives.



You may have noticed from the first video that there is gel applied to the patient. This accomplishes 2 things: Allows the probe to glide smoothly across the skin and also creates a "good connection" for the probe to transfer data across the patients skin. The room will usually have a "gel warmer" which is a small container used to warm the gel to a comfortable temperature. The elevated temperature makes the gel more fluid and offers greater comfort of the patient. (Nobody likes something cold applied to their skin.)

Finally, the introduction of very small handheld units have evolved to cater to the "bedside" ultrasound market. These units are designed to be light and easily carried from room to room. I would call them ultra-portable. They have less features and are not replacements for the full-size units.