Category Archives:Nuclear Medicine

How To Use a Geiger Counter

Leave a comment Nuclear Medicine, Quality Control, Radiation Safety
How To Use a Geiger Counter

In this week’s video, Eric from Olympic Health Physics explains how to use a Geiger Counter. Throughout the video, he demonstrates the Ludlum 14C with a pancake detector. He provides an overview of how to test the battery, how to ensure the counter is working properly, and how to read the panel.

What Is A Geiger Counter?

A Geiger Counter or Geiger Meter is an electronic instrument used to detect and measure the amount of ionizing radiation levels. They are widely used in various applications, including radiation protection and safety, radiation dosimetry, and the nuclear industry. If you work in a Nuclear Medicine department, you likely have a Geiger Counter to measure radiation in different aspects, such as wipe tests, area surveys, or exposure rate measurements.

Three Essential Checks Before Using Your Geiger Counter

When you’re using a Geiger Counter, there are three things that you need to check before you start using it. Throughout this post, we will be showing the Ludlum 14C with a pancake detector. Please note that there are many different Geiger Counter makes and models, so check your user manual for specific criteria for your equipment. 

1. Is The Geiger Counter's Calibration Valid?

The first thing is you need to make sure that the Geiger Counter is in calibration. You need to look at the calibration label on it to make sure that it is still within calibration.

The calibration certificate usually includes the last date of calibration and the expiration date. The sticker also includes other useful information such as the model numbers, serial numbers, and efficiencies. 

Geiger Counter Calibration Certificate

2. Is The Geiger Counter Responding Appropriately?

The second thing that you need to do is make sure that the instrument responds to a radiation source.

On this specific instrument, we have a check source with a window that we can we can open. We can then put our pancake detector over the cesium button source located on the side of the instrument to ensure the instrument is actually responding to radiation.

3. Are the Batteries Operating Within the Test Range?

The last thing you want to do is check the batteries to ensure the batteries are operating within the battery test range.

To test the batteries, first remove the pancake detector from the front of the Geiger counter. Then, turn the Geiger counter on and turn the knob to the lowest range setting. Test the battery by depressing the battery button and looking to make sure that the indicator stays in the battery test range. As long as the indicator stays within the battery test range, the battery is operating effectively. 

Geiger Counter Battery Test Button

Understanding the Instrument Scale Readout

Understanding how to properly read the instrument scale readout is important to ensuring you have the correct information.

You’ll note on the Ludlum 14C Geiger counter instrument there are three different scales on the face of the survey meter. The first scale or the bottom scale is in milliroentgen per hour. You can also notice that the very bottom scale indicates “X100 ONLY”. The second scale or the mid-range scale is also in milliroentgen per hour. The upper scale that goes across the top  of the readout is in counts per minute.

Instrument Scale Readout

Below the instrument scale readout on the top of the meter are the various potentiometer values you can set for the Geiger counter. On this particular model, the Ludlum 14C, there are five potentiometer value setting options you can select. The value selected determines the multiplication factor for any reading that you see on the face of the survey meter. 

The bottom three options include X0.1, X1, and X10 coincide with the middle and top readout. X100 is used for the bottom readout only. And the X1000 option is used for the internal probe only. 

Potentiometer Value Options

To understand how the potentiometer options and scale readout work together, consider the following example:

You select the value of X1 from the options available. When you scan the radiation source with the pancake detector, the needle on the readout stops at blue line on the example readout photo. In this example, the appropriate reading would be on either the middle or top scale range, depending on what information you require. In addition, the potentiometer value is X1, meaning the multiplication factor is only one. Therefore, the value seen is the actual measurement. So for this example, the reading is either 4,000 counts per minute or 1.2 milliroentgen per hour.

Suppose you had selected X10 and the needle result was the same. You would them multiple your readout results by 10 to determine your final measurement reading. 

Sometimes on your survey meter, you may notice no deflection of the needle at all. If this happens, it can often be caused by having it set on too high of a scale. To fix this, flip down to the lowest potentiometer scale and you should start to see needle deflection. 

Audio and Speed

The Ludlum 14C Geiger Counter also offers two additional options: audio and speed.

To turn the audio on, flip the switch up and you will hear the audible clicks of radiation being detected. There is also a speed setting for fast or slow. The fast speed setting is good when looking for any kind of contamination. The slow setting is ideal when making a direct measurement of the check source. 

Audio and Speed Options
Click for a downloadable version.

So now you know the three things that you need to check before you use the instrument. Check the battery, check the calibration sticker to make sure that it’s still within calibration and check against a radiation source to make sure that the instrument responds to radiation. We also covered how to read the different scales on the Ludlum instrument so that you know which scales to use and how to use the the dial setting to select the right potentiometer on the instrument.

Questions and comments about radiation safety? Feel free to shoot them over to us. We’ll be happy to respond to any questions or comments that you have around radiation safety programs and be a resource for you.

Our team is dedicated to ensuring that your facilities’ radiation safety program functions in accordance to regulatory standards, sound radiation safety principles, and most importantly serves to protect staff, patients, and the general public from the hazards associated with ionizing radiation. To this end, Olympic Health Physics can provide a physicist to your organization to fulfill the Duties of the Radiation Safety Officer. To learn more, check out our RSO Services or click the link below. 

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The Duties and Responsibilities of the Radiation Safety Officer

Leave a comment Nuclear Medicine, Quality Control, Radiation Safety
The Duties and Responsibilities of the RSO

In this week’s video, Eric from Olympic Health Physics provides an overview of the duties and responsibilities of the RSO or Radiation Safety Officer.

This video covers the regulatory requirements and expectations of a medical RSO following the guidance in NUREG 1556, Vol. 9, Rev. 3. that is specific to medical licensees.

What Is a Radiation Safety Officer?

The Radiation Safety Officer or RSO is the person within a medical licensee facility who is responsible for overseeing and implementing the radiation safety program. They are the ones responsible for ensuring that the facility is compliant with all of the regulations and overseeing that radiation safety program.

Twelve General Duties and Responsibilities of the RSO

We’re going to go through some of the typical duties and responsibilities of the Radiation Safety Officer. It’s important to note there can be many additional duties assigned to the RSO. Below, we outline twelve general duties of the Radiation Safety Officer in relation to the regulatory requirements and expectations of a medical RSO following the guidance in NUREG 1556, Vol. 9, Rev. 3. that is specific to medical licensees.

1. Stop Work Authority

The first duty of the Radiation Safety Officer is Stop Work Authority. What does this mean?

It means that the Radiation Safety Officer has the ability to stop any work involving radioactive materials. This is usually spelled out in what’s called a Delegation of Authority that comes from the facilities administration and assigned by facility administration, as well as the Radiation Safety Officer. Stop Work Authority is usually used whenever there are unsafe work practices and something needs to be fixed or changed before the work can continue.

2. Overseeing the ALARA Program

The Radiation Safety Officer has a responsibility to ensure that radioactive doses are kept ALARA. ALARA is an acronym that stands for As Low As Reasonably Achievable. Within the facility, the RSO is responsible for ALARA and implementing an ALARA program.

3. Managing Radioactive Materials Usage

They also oversee all radioactive materials uses, including monitoring and surveying of all areas where radioactive materials are either used or stored.

4. Implementing Policies and Procedures

The RSO is responsible for drafting and implementing policies and procedures that deal specifically with the security of radioactive material, emergency procedures and operations that employ radioactive materials.

5. Training For Workers Handling Radioactive Materials

The Radiation Safety Officer typically conducts training for radioactive materials workers. They’re going to be providing training about the use and safety of radioactive materials within the facility.

6. Transportation, Delivery, and Radioactive Materials Limits

They are also  responsible for the safe transportation and delivery of radioactive materials. The RSO ensures the packages are checked in properly, that there are surveys of packages and all deliveries are documented. Radiation Safety Officers also ensure that the facility’s possession limits are adhered to. The possession limits are outlined in the radioactive materials license for the facility. The RSO is responsible for making sure that the facility doesn’t exceed radioactive material possession limits.

7. Dosimetry Program

The RSO is also going to oversee and potentially implement the dosimetry program. Dosimetry is how we measure or monitor radiation doses, such as occupational radiation exposure, for staff. 

8. Security of Radioactive Materials

Security of radioactive materials fall under the jurisdiction of the Radiation Safety Officer to ensure that any radioactive material is going to be secured from unauthorized removal. This is typically done in one of two ways. Either the radioactive material is going to be under lock and key of some sort, or it can also be under constant surveillance. So the radiation safety officer will be responsible for making sure that radioactive materials are secured in one of these two ways.

9. Documentation of the Radiation Safety Program

Documentation is a really big topic because any time we’re dealing with radioactive materials, we have to document most of the processes that go with them. Some of the documentation include surveys, inventory, receipt, and disposal of waste. All of these activities should be documented.

10. Liaison With Regulators

They’re also going to serve as a liaison with regulators and report any medical events or anything that’s a reportable event. The RSO will report events either to the state, if they’re in agreement state or to the NRC, if they’re not in an agreement state.

11. Managing the Radioactive Materials License

The Radiation Safety Officer may manage the radioactive materials license. This can include implementing any license conditions within the radioactive materials license, as well as submitting any amendments to the regulatory agency for changes to the license. Amendments are typically going to be for things like:

• changing an authorized user
• changing the radiation safety officer
• changing the address of the facility
• changing the name of the facility
• changing the proposed uses or the locations of those uses

All the above are typical things that would require submitted amendments.

12. Implement Corrective Actions

And lastly, the RSO implements any corrective actions for deficiencies or inefficiencies that are found in a radiation protection program, audits or external inspection conducted by a regulatory agency.

Duties of the RSO

So this gives you a high level overview of the duties and responsibilities of the Radiation Safety Officer. The RSO may have more duties than what we’ve listed here. It’s usually up to the organization on what those responsibilities and duties will be for the RSO, but this will give you a pretty good place to start to understand the role of an RSO.

Questions and comments about RSO duties? Feel free to shoot them over to us. We’ll be happy to respond to any questions or comments that you have around Radiation Safety Officers and be a resource for you.

Our team is dedicated to ensuring that your facilities’ radiation safety program functions in accordance to regulatory standards, sound radiation safety principles, and most importantly serves to protect staff, patients, and the general public from the hazards associated with ionizing radiation. To this end, Olympic Health Physics can provide a physicist to your organization to fulfill the Duties of the Radiation Safety Officer. To learn more, check out our RSO Services or click the link below. 

Contact Us for a No Obligation Quote

253-254-6988
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What You’re Missing in Your Symbia Gamma Camera QC

Leave a comment Nuclear Medicine, Quality Control
What You're Missing in Your Symbia Gamma Camera QC

In this post, we’re going to be talking about something that you might not know about your Siemens Gamma Camera quality control.  

We’re going to be talking about the very popular, widespread Siemens Symbia, and this post is going to cover every version of Symbia that’s out there, because for this purpose, the same issue is present. 

What we’re going to be talking about is uniformity and how we evaluate the uniformity images on a Siemens Gamma Camera.

There’s one aspect of evaluating the uniformity images that a lot of technologists don’t really know.  And unfortunately, the reason is because the essential information is buried in the quality control portion of the manual.  

Watch the video above on our YouTube channel as Eric explains what you may be missing during your Siemens Symbia Gamma Camera quality control.

Deep inside the Quality Control portion of your Siemens Symbia gamma camera is a section on the criteria for evaluating the uniformity of images. Follow along  as we show you where to find this important information.

Standard Uniformity Analysis

Often nuclear medicine technologists are taught to evaluate the quantitative part of the uniformity analysis by looking at the numbers and making sure that it’s less than 5%. 

This is a general rule of thumb. 

But for the Siemens system, there are actual values or limits that are associated with each of the four quantitative metrics that we get when completing daily quality control. 

So, let’s dive into the quality control manual and show you what those metrics are and show you why it’s important. As a note, for this post, we are using the Operator’s Manual for the Siemens Symbia Intevo 16/6/2 and Intevo Excel Series.

Cover Page for Siemens Symbia Gamma Camera

Uniformity Values

Within the Operator’s Manual, we can find the specific Uniformity Values by turning to the Quality Control and Assurance section.

For our example in this post, if you look on page 290, you can find a table with Uniformity Values. And while a general rule is to have values less than 5%, you can see from the table that each value is unique.

The table provides the values for Integrated CFOV, Integrated UFOV, Differential CFOV, and Differential UFOV. 

Each of these values is different because each of measuring using unique criteria measuring a different physical aspect of the image. Note that these are all intrinsic values for 10 million counts.

Intrinsic Uniformity Values

Now that we’ve found the intrinsic uniformity values, we can find the extrinsic values on page 301 of the Operator’s Manual in our example. We can see that this set of criteria are slightly different.

We still have 6% and 5% for the Integrated CFOV and UFOV. However, for the Differential, now we’re at 3.5% for CFOV and 4% for UFOV.

Whenever we’re doing our flood images, we need to make sure that we’re looking at the intrinsic criteria for any intrinsic floods that we’re doing, and we’re should be looking at the extrinsic criteria for any extrinsic floods that we’re doing. Again, these are for 10 million count floods and this is for the intrinsic verification or the extrinsic verification.

Extrinsic Uniformity Values

Example of a Uniformity Value Comparison

In this example, we will use an intrinsic verification from a Siemens MBA. When we look at each of the numbers. The reason we use this specific example is because there is no indication on the screen image that this flood actually didn’t pass.

So which criteria did not pass?

Side-By-Side Analysis

Let’s just do a side by side against what the intrinsic values are versus what we actually calculated or measured.

When reviewing the image results with the actual values in the Operator’s Manual Quality Control section, we can see that we’re fine with everything here except for Detector 1, Integrated UFOV. This value shows 3.19%, yet the criteria is only 3%.

Uniformity Value Comparison
Intrinsic Uniformity Values

There is no indication on the screen that one of the values hasn’t passed the QC standard. This is somewhat problematic with the Siemens systems because you don’t actually know whether you pass or fail the criteria automatically. You have to apply the criteria from the manual to determine whether or not you pass or fail the the test. 

What Do You Do If a Value Fails?

So if you have a value that fails like this 3.19%, when the criteria is 3%, what do you do?

The first thing we recommend to people to do is to go through a tuning and peeking exercise on the equipment. Go through the tuning and peaking exercise, do all of the things that you can run before you get to the uniformity test and then rerun the flood.

Oftentimes that will correct the issue. If that doesn’t correct the issue, you can go back in and rerun and an intrinsic calibration. When you run an intrinsic calibration, we sometimes call that a high count flood. With the Siemens systems, you need to do at least 120 million counts. 

Oftentimes they’re set to 200 million counts, and this can be quite timely. But when you’re redoing that intrinsic calibration you’re going to smooth out any non uniformity that you see in the intrinsic verification. When you do the intrinsic calibration, there is a specific criteria associated with it that you can find in the manual.

For intrinsic calibrations, we say that they can compensate for values up to about 10%. If you exceed 7% for the calibration, then you need to contact service. If your intrinsic calibration passes and you don’t see any issues, you’re below the 7% on the intrinsic calibration. 

Now you can rerun your intrinsic verification or daily flood and see if you you pass those values. If you are still not passing those values, that’s the point that you should probably contact either service or contact your physicist to try to get some direction on what it is that you need to do in order to get your camera to pass the manufacturer stated specifications.

A Common Misconception

There’s a common misconception that the screen will turn red if a Verification Flood value fails. As long as it doesn’t turn red, you’re going to be fine.

That’s actually not true with the Siemens systems. You have to pay attention to what the values are and evaluate against what’s in the manual to determine whether or not your uniformity images are actually passing the manufacturer’s specifications.

We hope that this article and video has provided you with awareness of things to consider when testing your Symbia Gamma Camera to ensure it pass the manufacturer’s standards. If you have questions or comments, please reach out to us at info@olympichp.com and we’d be happy to assist you. 

Your medical physicist is a great resource for you when designing your Quality Control Program, nuclear medicine testing, and ACR accreditation.  You can also always reach out to us if you have questions or want more information on why you should partner with us. 

Contact Us for a No Obligation Quote

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How Long Do I Need To Keep Nuclear Medicine Records?

Leave a comment Nuclear Medicine
Nuclear Medicine Records Retention

How Long Do I Need to Keep Nuclear Medicine Records?

As a Nuclear Medicine Technologist or imaging facility administrator, there are many required records and documentation to complete for compliance with NRC regulations. In this post, we break down the records you are required to keep and for how long. 

Watch the video above on our YouTube channel as Eric talks about nuclear medicine records retention.

Nuclear Medicine Records Retention

The Nuclear Regulatory Commission has specific criteria regarding records and reports. For more information on individual record keeping, the NRC website has excellent resources you can find here. 

Three-Year Retention Records

Most regulatory records in nuclear medicine fall within the three-year retention period. 

The records that are required to retain for three years include:
☑️ Sealed Source Inventory Records
☑️ Sealed Source Leak Testing
☑️ Area Survey Logs
☑️ Radioactive Waste Disposal Records (for anything that you store and decays)
☑️ Moly99 Break Through Tests (if you’re still using generators)
☑️ Dose Calibrator Test (for example: daily constancy, quarterly linearity, geometry tests and accuracy tests)
☑️ Radiation Safety Training Records
☑️ Written Directives (for example: I-131 or otherwise)
☑️ Patient Release Data, Criteria or Calculations
☑️ Patient Dose Administrations Records
☑️ Instrument Calibration Certificates (for example: if you have Geiger counters or iron chambers, you need the instrument calibration certificates)

Five-Year Retention Records

Next up is the five year retention period. These are the records that you’re going to need to keep for a period of five years:
☑️ Radiation Safety Committee Meeting Minutes
☑️ Radiation Protection Program Documentation (for example: authority responsibility changes, change of scope, or program changes)

License Lifetime Retention Records

Last, there are specific records that you need to retain for the duration of the radioactive materials license. 

The records you must keep for the lifetime of the license include:
☑️ Occupational Dosimetry Reports
☑️ Procedures for Administrations That Require a Written Directive

Nuclear Medicine Record Retention
Click on the image for a downloadable PDF file.

We hope that this article and video has provided you with some guidelines for your nuclear medicine record keeping and retention. If you have questions or comments, please reach out to us at info@olympichp.com and we’d be happy to assist you. We also offer various record keeping resources for download on our Resources and Forms page.

Your medical physicist is a great resource for you when designing your Radiation Safety Program.  You can also always reach out to us if you have questions or want more information on Radiation Safety or want to see why you should partner with us.  We also offer Radiation Safety Officer Services, Radiation Dose Optimization, and Health Physics Services.

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