Sean L. Johnston, MD, PhD
Radiologist | Body Imaging
234 Goodman Dept. Of Radiology Cincinnati OH, 45219About
Sean L. Johnston, MD, PhD is a board-certified radiologist currently serving his patients at Adventist Health White Memorial located in Los Angeles, California. Attributing his success to perseverance, Dr. Johnston is a board-certified radiologist who serves patients within the Diagnostic Imaging Department at Adventist Health White Memorial. As the region’s leading faith-based, nonprofit teaching hospital, Adventist Health White Memorial strives to inspire wellness and treat medical conditions using the latest technology, equipment, and techniques. The team of highly trained and experienced doctors, nurses, surgeons, and countless other medical professionals goes to work each day with one goal: to help patients heal. They believe in treating each patient as a whole, offering physical, emotional, and spiritual care. After earning his medical degree and his PhD with a focus on transplant immunology from the Mayo Clinic Alix School of Medicine, Dr. Johnston went on to complete his surgical fellowship at the same educational venue. He subsequently completed his internship in internal medicine at UCSF Fresno, before going on to complete his residency in radiology and his fellowship in vascular & interventional radiology at the University of California, Los Angeles (UCLA). During his training at UCLA, he was honored with one of five nationwide educational scholarships from Bracco Diagnostics and was named one of their Leaders on the Horizon. With an impressive professional journey filled with numerous achievements, the doctor is board-certified in diagnostic radiology and interventional radiology by the American Board of Radiology, which is a not-for-profit physician-led organization that oversees the certification and ongoing professional development of specialists in diagnostic radiology, interventional radiology, radiation oncology, and medical physics. He also has extensive experience designing and building tele-radiology systems for imaging and medical centers, including implementation of digital dictation. Outside of practicing medicine, Dr. Johnston enjoys spending time with his children. His favorite professional publications are the New England Journal of Medicine and the Journal of the American Medical Association.
Sean L. Johnston, MD, PhD's Videos
Education and Training
Mayo Clinic
Board Certification
American Board of Radiology- Radiology
RadiologyAmerican Board of RadiologyABR
Provider Details
Sean L. Johnston, MD, PhD's Expert Contributions
What do the results mean from my CT scan?
A radiology report is designed for the referring physician to view in context of your entire medical history in order to give them key information for any treatment/therapy planning or lifestyle modification. In general, these are not meant to be interpreted by non-physicians, as they tend to consult with Dr. Google and arrive at erroneous conclusions. This report is best discussed with the primary care physician that ordered it in the first place so they can best answer your question. However, in brief, you have a small right ovarian cyst which is very common. It will be up to the referring to decide how to best monitor this. The endometrium (a portion of the uterus which normally changes with your cycle) is most likely in a phase just prior to your cycle. This needs to be confirmed and perhaps monitored in another six weeks. The structure in the left adnexa (near the left ovary) is indeterminant. It will be up to the referring to decide how to best monitor this. A small amount of free fluid in the pelvis is normal for menstruating females. Probably not the definitive answers that you are looking for, but again, radiology findings are a piece of the whole puzzle. The referring needs to assemble them. I recommend talking to them about this report at your earliest convenience. Best of luck. READ MORE
How does a renal ultrasound work?
Ultrasound uses sonar technology from submarines to create an image of internal organs and structures on the computer screen for the radiologist to interpret. The test involves putting a sticky gel on the skin and placing a transducer (about the size of a fist) on the skin surface. The sonar waves are directed into the body. The test is painless, uses no radiation at all, and gives important information. Good test to look for obstruction and stones within the kidney. Best of luck! READ MORE
What is the difference between an MRI and CT?
Two entirely different ways to look at the same area. The MRI uses magnets and takes a long time in an enclosed space, so if you have a pacemaker it won't be the best for you unless you have one that is MRI compatible. Also, if you are claustrophobic, can significantly impact the test. The CT uses radiation and is best to look for subtle fractures. Best thing to do is simply ask your doctor...sure he has good reasons! Best of luck! READ MORE
What does an MRI angiography show?
MR angiography is an MRI, which uses magnetic fields rather than radiation, designed to look specifically at your blood vessels. It is generally used to look for any narrowings in vessels, aneurysms (regions that are abnormally large), or damage to the vessels such as dissections, where part of the lining of the artery is torn. Hope this helps! READ MORE
Is an MRI scan safe for children?
Yes. The benefit of an MRI over a CT is that there is no radiation involved. I hope your son feels better! READ MORE
What is a lung PET scan?
A PET scan involves injection of a small amount of radioactive material that collects in regions of active metabolism. A lung PET is designed to see if there is active metabolism in a mass within the lung. If so, that mass will need to be addressed further. Follow the preparations given by the imaging center. They are not too restrictive. Best of luck! READ MORE
Why is a CT scan necessary for pneumonia?
In general, a CT scan is not necessary for this indication. Typically, just a chest X-ray will do. However, if he is worried about an atypical infection (walking pneumonia) or other types of lung disease, a CT is better. Just ask your provider what's on his mind! READ MORE
Is an MRI scan painful?
No, but it is loud, and if you have claustrophobia, it will not be pleasant for you as the tube is tight. Your technologist will provide you with ear protection but know in advance it is not a quiet procedure. Best of luck! READ MORE
What are MRI results supposed to indicate?
That's actually a much larger question. Please consult with your ordering physician what they are interested in finding. Any radiological examination provides a tremendous amount of information, designed to aid referrings into making the best treatment choices, MRI included. READ MORE
My son has been having bad headaches. His neurologist is sending him to a radiologist. What can we expect next?
Most likely the neurologist requested an MRI. Your son will be given a set of headphones to cover his ears and placed in a fairly tight tube. If he is claustrophobic he will not like the procedure, as his head will have to be in the tube. The scan actually takes around a half hour, and the test results will depend on his ability to hold still. Too much motion will cause blurring on the images, which will make interpretation difficult. That being said, the test will be over shortly and you will receive the results most likely within a day. good luck! READ MORE
I accompanied my mother for her X-ray and I didn’t know I was pregnant then. What should I do?
The risk of radiation effects on a fetus for a back radiograph series on a person standing away from the patient is extremely, extremely low. You actually receive over twenty times more background radiation from radon sources in your home than you will from that single medical exposure. So, rest assured and congratulations! READ MORE
How can I ensure no other cancer cells are present in my body?
The best way to check for distant metastases is a separate scan called a PET-CT, which helps detect the presence of cancer cells throughout the body. Periodic surveillance will be necessary, so be sure to keep your appointments and follow the recommendations of your oncologist. Best of luck. Sean L. Johnston, MD, PhD READ MORE
What if I'm allergic to contrast?
Contrast allergies should always be taken seriously. While most people have a similar level of reaction, there are cases where a person with a minor allergy at one session had a major reaction (as in airway compromise) at a later setting. If you need a CT with contrast in the future, you should ask your primary care physician to prescribe the pre-treatment protocol that is in place at your local hospital or imaging center. This usually involves a short course of steroids prior to the administration, which stops the allergic reaction from even starting. READ MORE
Is pregnancy possible after chemotherapy?
It is possible, although much less likely, as chemotherapy tends to hamper fertility. Doesn't make it impossible, but your sister needs to know the odds are a bit against her at this point. Breast feeding will be fine, as the radiation does not cover the opposite breast. Best of luck! READ MORE
Airport security and being pregnant
Hello- Yes, you may go through the scanner at the airport. The radiation dosage is so low that it doesn't pass through the skin, and therefore does not provide any significant increased risk to your fetus. Congratulations! Sean L. Johnston, MD, PhD READ MORE
Areas of expertise and specialization
Internships
- USCF Fresno
Fellowships
- UCLA (Interventional Radiology)
Hobbies / Sports
- Time with his Children
Favorite professional publications
- New England Journal of Medicine, Journal of the American Medical Association
Sean L. Johnston, MD, PhD's Practice location
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Cincinnati, OH 45219Get Direction
Sean L. Johnston, MD, PhD's reviews
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Get to know Radiologist Dr. Sean L. Johnston, who serves patients in Los Angeles, California.
Attributing his success to perseverance, Dr. Johnston is a board-certified radiologist who serves patients within the Diagnostic Imaging Department at Adventist Health White Memorial in Los Angeles, California.
As the region’s leading faith-based, nonprofit teaching hospital, Adventist Health White Memorial strives to inspire wellness and treat medical conditions using the latest technology, equipment, and techniques. The team of highly trained and experienced doctors, nurses, surgeons, and countless other medical professionals goes to work each day with one goal: to help patients heal. They believe in treating each patient as a whole, offering physical, emotional, and spiritual care.
After earning his medical degree and his Doctorate (PhD) degree with a focus on transplant immunology from the Mayo Clinic Alix School of Medicine, Dr. Johnston went on to complete his surgical fellowship at the same educational venue. He subsequently completed his internship in internal medicine at UCSF Fresno, before going on to complete his residency in radiology and his fellowship in vascular & interventional radiology at the University of California, Los Angeles (UCLA).
During his training at UCLA, he was honored with one of five nationwide educational scholarships from Bracco Diagnostics and was named one of their Leaders on the Horizon.
With an impressive professional journey filled with numerous achievements, the doctor is board-certified in diagnostic radiology and interventional radiology by the American Board of Radiology, which is a not-for-profit physician-led organization that oversees the certification and ongoing professional development of specialists in diagnostic radiology, interventional radiology, radiation oncology, and medical physics. He also has extensive experience designing and building teleradiology systems for imaging and medical centers, including implementation of digital dictation.
Radiology is a medical specialty that uses medical imaging to diagnose and treat diseases within the human body. Radiologists are medical doctors who specialize in diagnosing and treating injuries and diseases using medical imaging procedures, such as exams and tests, X-rays, computed tomography, magnetic resonance imaging, nuclear medicine, mammography, positron emission tomography, and ultrasound.
Outside of practicing medicine, Dr. Johnston enjoys spending time with his children. His favorite professional publications are the New England Journal of Medicine and the Journal of the American Medical Association.
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