5 Tips When Your CT System Is Not Scanning

A GE CT Technologists guide to surviving Scan Hardware Stopped Scan and Operator Paused Scan errors.

Receiving errors when attempting to scan a patient is the last thing a CT technologist wants to see. Everything from a full schedule of patients, scanning trauma patients and receiving scan errors after injecting patients with contrast can lead to a lot of stress, but there is no need to panic. We are always here to help. We have provided a few tips to help you get your system scanning in no time.

Intended to be used as a resource reference and is not intended to be a professional recommendation. Consult with trained Service Engineer before attempting the following procedures. Always follow all safety precautions.

#1 Check Gantry Status

Most scan hardware errors are due to issues relating to communication with the CT gantry, that is why it is important to recognize the characteristics of a CT system that is ready to scan. Take a look inside the scan room for a quick status check.

  • CT Systems that are ready to scan will show a number at the top of the gantry (as seen above) indicating that the cradle encoder is tracking correctly. If you see flashing 8’s then move your table all the way out then down/up, in/out until the encoder begins tracking at the top of the gantry.
Left Gantry Interface Panel
  • A green LED status light should also be illuminated on the left and right gantry interface panels. If green LED is off or blinking, press the button next to it (Labeled as button #1). Also press this button if your receive “x-ray drive and power disabled” error. This is your emergency reset button that can sometimes be tripped by bumping into the side of the cradle, pushing emergency off buttons, or by performing system shutdowns.
  • Is your cradle unlatched? (Indicated by green 3-prong cradle status light at the top of the gantry) Press the cradle latch button on either the left or right side gantry interface panel (Labeled as button #2)
  • If you do not see any lights on the gantry and your operator console has completely booted up, please skip to #3 Perform Scan Hardware reset

#2 Check Your System Error Log

Your system log updates every 5 seconds and will show the cause for your Scan Hardware Stopped Scan failure or any other system issues. Detailed instructions and video are provided below as reference.

Instructions for viewing error log:

  • 1. On right side monitor, click on your System Status bar (it is the grey button located under your film composer status, it will sometimes have a message such as “scanner hardware reset successful” but will most often have no message)
  • 2. A screen will populate that will show various system status messages. Close, View Log, Clear, and Memo buttons can be seen at the bottom of this screen. Review the status messages as they can be indicative of cause of issue. If there is no status message relating to issue, click on “View Log” to view error log
  • 3. Your system log will populate and error messages will be listed in chronological order with the most recent messages at the bottom. Important: Wait 5-10 seconds and then click “Last Page” when it is no longer grayed out to view the most recent error message.
  • 4. Click on “Prior” and “Next” to scroll by page or use the scroll bar on the right side of monitor. Analyze error messages to see if there is a message regarding scan failure. Use the timestamps to match the error messages to the time of original scan failure

#3 Perform Scan Hardware Reset

If you have lost communication with at least one of the controllers of your CT system, a scan hardware reset may be necessary to re-establish communications between the operator console and CT Gantry. Detailed instructions are provided below:

  • Important: Before attempting scan hardware reset, make sure to end all exams, as this could lead to error acquiring scan resources during scan hardware reset.
  • 1. Click on the Service icon that is located on the top left corner of your right-side monitor. It is located next to the “Exam Rx” icon.
  • 2. Wait for Service Browser to populate. Then click on “System Resets” on the bottom left corner of service browser.
  • 3. System Resets menu will populate. Click on “Scan” to make sure it is highlighted and then click on “Run.” You will receive message stating hadware reset is being performed. This process will take about 5 minutes. If scan reset fails, makes sure to end all exams and perform scan reset procedure once again. If successful, continue scanning.
  • 4. If failures persist, check the system error log to see detailed message regarding scan reset failure. Refer to #2 Check Your System Error Log

#4 Perform System Shutdown and Reboot

If the previous tips have not already helped you resolve your issue, a full system shutdown or system reboot may be necessary. Important: Always follow proper shutdown procedure. Failure to do so may lead to hardware or software damage.

After “system halted” message appears on your screen, it is safe to power off console using flip-switch located on the left side of console unit. Consult with engineering before powering off any electrical panels. It is recommended to shutdown system from main disconnect and wait at least 30 seconds before restarting system. Pressing Start or On button may be necessary to restore power to system from main disconnect. Do not attempt to power off or on any electrical unit you have not had proper training handling.

Once power has been restored to gantry, flip the console power switch to the “On” position and wait for system to finish booting to applications. Perform QA scan and asses system status.

#5 Call Your Service Engineer

If you have tried all of our previous tips and your are still receiving “Scan Hardware Stopped Scan” errors, it may be time to call in your service engineer.

It is often very helpful to take a picture of your error log and forward that information to the service engineer. They are trained to sift through all the jargon in your error log and can find the nugget of information you are looking for. It allows your service engineers to get an idea of your issue and prepare by bringing parts with them which can help speed up your service time.

If you would like some assistance finding highly-recommended service companies for your CT system or need technical support, please visit our contact us page for phone and email or send us a message. We would love to hear from you!

Make sure to check out our Resources Page for more amazing content.

Our goal is to provide you with a wealth of resources so your system can keep scanning. We are always adding new content so check back often!

Top 5 questions asked by patients prior to CT scan.

MRIPETCTSOURCE understands that there is often more questions than answers when you are undergoing imaging procedures. We are here to provide you with the resources you need. In this Blog Series, we will answer questions commonly asked by patients prior to a CT exam.

  1. Q: Are CT scan results instant? How long before I receive results for CT scan? Are CT Scan results available immediately

A: Computed Tomography images are reconstructed within minutes of ending exam. Images can be viewed by your technologist but can only be read by a Radiologist to diagnose any medical conditions. Upon ending your exam, Images are immediately sent to a PACS system so they may be available for your Radiologist to read. Results are forwarded to GP and results are typically made available to patients within 24 – 48 hours of exam.

Q: What does the “CT” in CT scan stand for? What Does CT mean?

A: “CT” is short for Computed Tomography. It refers to the powerful image reconstruction and generation computers that render images out of the raw data received from the X-ray generation and detector assemblies

Q: How much radiation in a CT scan? Radiation exposure in a CT Scan

A: The effective dose for radiation exposure is measured in milliSeiver, mSv. According to recent study by Stanford Medical, the average U.S. citizen receives about 3.6 mSv per year in ambient environmental radiation exposure.

  • Chest X-ray approximate radiation dose of .1 mSv
  • Mammography exam approximate radiation dose of .4 mSv
  • Head CT Scan approximate radiation dose of 2 mSv
  • Chest CT scan approximate radiation dose of 7 mSv
  • Abdomen CT scan approximate radiation dose of 10 mSv

*Radiation dose may double if using contrast due to repeated scan after contrast injection.


4. Q: Can a CT scan detect cancer?

A: CT scans can be used to detect and monitor cancer, tumors and masses within the anatomy. Contrast agents are administered to patients that highlight the growth and metastization throughout the body. Dedicated oncology imaging systems will often have a PET scanner paired with a CT system. This allows for precise tracking throughout the anatomy with both systems while minimizing radiation exposure. Images from both systems are overlaid and read by a radiologist.

5. Q: Are CT scans dangerous?

A:  Computerized tomography is at the forefront of a medical technological innovation. New methods and systems are being developed that result in lower scan times and exponentially less radiation exposure than prior methods. We have a table available above that gives you a relative spectrum of expected radiation exposures during a CT scan. These values are averages and can vary between systems. CT scans are safer than they have ever been before. Increased risk of cancer due to CT scans is so minimal that the American College of Radiology considers it so small that it cannot be reliably measured. One must consider that even though exposure is minimal, patients are still subjected to radiation and for that reason the American College of Radiology advises that patients only undergo exam when there is a clear medical benefit (cases such as trauma, oncology, monitoring disease, aid in diagnosis)


Thank you for joining us! This is the first part of our Q & A Blog Series, so check back often for new content. If you have any questions you would like answered feel free to visit our Contact Us page and send us a message. We would love to hear from you!

Questions commonly asked by patients before an MRI scan

In this blog series, we will be answering all of

The moment when your doctor tells you that you will be needing an MRI scan can be a stressful time that is filled with more questions than answers. MRIPETCTSOURCE.com is here to provide your with the information you need so that you know what to expect and you may be confident going in to your diagnostic procedure.

Q: What does MRI scan stand for?

A: MRI scan refers to Magnetic Resonance Imaging (MRI). It is a method of obtaining diagnostic quality image of the anatomy using superconductive magnets (Magnetic), High-frequency RF waves (Resonance), and computed image reconstructions (Imaging) to obtain high definition images that can be viewed by a radiologist.

Q: What does an MRI show?

A: MRI exams are ordered by a radiologist when detailed images of soft tissue, bone, organs, liquids inside the body or other anatomical structures are needed to diagnose a medical condition. An MRI scan can be used to detect anomalies in the anatomy such as tumors, cancer, trauma, infection, or developmental abnormalities. MRI scans of the brain can show trauma, stroke, multiple sclerosis, causes of headaches, and signs of dementia. New research with functional MRI (fMRI) can also detect the likelihood that someone will be able to quit smoking.

HD Brain MRI, Sagittal View

Q: Will MRI scan show cancer? 

A: An MRI scan is used for oncology patients to determine whether a tumor is cancerous or to determine whether cancer has metastasized into other regions of the body. A patient is typically injected with a contrast agent that highlights cancer in the anatomy.

Q: Is MRI scan painful?

A: An MRI scan is typically not painful. An MRI scan is a non-invasive procedure that utilizes a magnet and radio frequencies to produce detailed images. The patient is typically provided with ear protection but will still be able to hear the various radio frequencies as the scan progresses. Most discomfort during scans reported by patient occurs due to the various positions patients must lie in during MRI scan. Head MRI scan, Neck MRI scan, Shoulder MRI scan, Spine MRI scan, Knee MRI Scan, Foot MRI scan procedures allow patients to lie on their backs. Extremity scans, as with Wrist MRI scan procedures, can have patients lying on side or in “superman” position.

Q: Is MRI scan scary?

A: An MRI scan is not scary and does not have to be an intimidating experience. Most patients that have bad experiences during an MRI scan complain of anxiety or claustrophobia when having to enter the magnet. Many patients also have difficulty staying still during their exam due to injury or positioning during scan. The majority of patients have no issues during their exam and some even find it to be the perfect time to take a short nap. Many imaging centers offer many patient comfort accessories, such as headphones that let you listen to your favorite playlist during your MRI scan, earplugs, pillows, blankets and many more.

Q: Is MRI scan safe? 

A: Magnetic resonance imaging is among the safest methods of acquiring diagnostic quality images of the anatomy. MRI scans are non-invasive procedures that uses a magnet and radio frequency to create images of the human body. Patients are typically screened for any foreign metal objects before entering the magnet room. The superconductive magnet has no effect on any biological function of the human body. Should an emergency occur, MRI systems are outfitted with multiple safety switches that allow the MRI technologist to immediately end the exam and shut off power to system or quench the magnet, effectively removing the magnetic field from the magnet, if needed in extreme circumstances.

Related questions: Is MRI scan for cancer? Is MRI scan harmful? Is MRI scan radiation? What will MRI scan show? What’s an MRI scan? What is an MRI scan used for? What MRI scan can show? What does an MRI scan do? Can MRI scan detect cancer? How safe is MRI scan? How is MRI scan used? Is MRI scan claustrophobia?

Why are MRI scans so expensive?

The cost of an MRI scan has many factors that contribute to the overall price paid out-of-pocket by the patient. One of the largest costs associated with Magnetic Resonance Imaging is the initial cost to purchase and install an MRI scanner. A new MRI scanner with high definition MRI coils, software imaging options and installation can run into the millions of dollars.

Accredited hospitals and imaging centers also require a full range of staff, medical equipment, medical facilities and Radiologists to read the images. In order to produce accurate and detailed images, MRI scanners have to be calibrated, maintained, and repaired by specially-trained service engineers.

1.5T GE MRI DQA Phantom
Axial slice of Quality Assurance phantom used to calibrate GE MRI

An MRI scan utilizes superconductive coils which are submerged in thousands of liters of liquid helium. The transfer of liquid helium into the MRI also requires hiring a highly specialized cryogen technician to perform service (video can be seen below). The cost of refilling liquid helium can be as much as $11/liter and MRI systems can boil-off as much as 2500 liter per year.

The video below shows the specialized process of transferring liquid helium into an MRI scanner.

The cost of parts to repair an MRI system when a system is unable to scan can be very expensive, so many hospitals and imaging centers opt to sign service contracts with either the manufacturer or a third-party service provider. Costs for a service contract can range from $5k/month to $25k/month depending on coverage. An MRI service contract can help to reduce the cost of an MRI by covering any costs associated with a down scanner and providing resources for liquid helium refills, coil replacement, and parts coverage.

Overall, the patient is receiving diagnostic imaging services using state-of the art equipment in a medical facility. As with any specialized procedure, one can expect to pay a premium for the service so patients must be diligent in their research to find an imaging center that meets their financial and medical needs. It is always recommended to call multiple imaging centers in the local area and schedule an appointment with the imaging center that the patient is most comfortable with.

What is inside of a PET scanner?

A PET scanner utilizes a ring of detector modules to precisely map gamma ray coincidences. A standalone PET scan can often be unclear and can be difficult to distinguish precise location of anatomical structure so PET scanner are often paired with CT Scanners or MRI Scanner. In this video, we can see a PET system paired with a CT System to produce a PET/CT System. The upper portion of the ring of detector modules can be seen in the rear of the gantry and the CT system is in the forefront.

Related Questions: How does PET scanner work?