Understanding Radiation Exposure: X-rays vs. MRI for Sinus and Head Issues
MRI Radiation Dose The radiation dose from a sinus X-ray is approximately 0.1 mSv, while a head MRI does not involve ionizing radiation and therefore has a radiation dose of 0 mSv. In contrast, a head CT scan typically exposes a patient to about 2 mSv of radiation. If your doctor...
Dr. Yang Jinghua Reply:
To lo2285: Regarding the implementation of medical imaging, clinical symptoms should be taken into consideration. For the evaluation of sinusitis, X-rays and computed tomography (CT) should be the primary modalities. When assessing the brain, computed tomography and magnetic reso...[Read More] Understanding Radiation Exposure: X-rays vs. MRI for Sinus and Head Issues
Differences Between Chest CT and Low-Dose CT for Lung Cancer Screening
What is the difference between chest CT and LDCT? Hello Dr. Yang, I would like to ask three questions: 1. Regarding lung cancer screening, is there a difference between a chest CT scan (without contrast) covered by health insurance and a low-dose chest CT scan (LDCT) that is se...
Dr. Yang Jinghua Reply:
Dear Mr. Chang, Regarding general chest computed tomography (CT), it is necessary to evaluate various structures in the chest. A single examination of low-dose chest CT (LDCT) typically involves a radiation dose of about 7 millisieverts (mSv) and is focused solely on assessing l...[Read More] Differences Between Chest CT and Low-Dose CT for Lung Cancer Screening
Understanding PET/CT vs. CT: Radiation Dose and Resolution Differences
The resolution issue between PET/CT and CT? Hello, doctor. Is there a significant difference in radiation exposure between a whole-body positron emission tomography (PET) scan and a chest and neck computed tomography (CT) scan? Also, I've heard that the resolution of a PET s...
Dr. Yang Jinghua Reply:
Dear Kay, Regarding the radiation dose of a whole-body positron emission tomography (PET) scan, in addition to the dose from the radiotracer, which is approximately 7 millisieverts (mSv), the dose from a single computed tomography (CT) scan is about 2 to 15 mSv, resulting in a t...[Read More] Understanding PET/CT vs. CT: Radiation Dose and Resolution Differences
Do X-Ray Examinations Leave Radiation Residue on Metal Items?
Radiation concerns in medical imaging? I would like to ask the doctor: If I do not remove my watch and glasses (metal frame) as well as my metal-framed underwear during an X-ray, will there be any radiation residue left on these items after the X-ray, and could this potentially a...
Dr. Yang Jinghua Reply:
Ms. Liu: Hello, currently, medical X-rays only have a portion of their energy absorbed by the irradiated body during exposure, and the energy is immediately dissipated; it does not accumulate in metallic objects. The impact on the human body is minimal, so please do not worry. Th...[Read More] Do X-Ray Examinations Leave Radiation Residue on Metal Items?
Is Radiation Exposure from Medical Imaging Safe? Understanding Risks and Recommendations
Can radiation be excessive? Doctor, if I had a standard dose chest CT and three X-rays for follow-up less than three months ago, and now I'm going for a mammogram, will the radiation exposure be excessive? Should I wait a few months before doing it? If the doctor advises tha...
Dr. Yang Jinghua Reply:
Dear Ms. Lin, Hello, currently there are no regulations governing the use of imaging examinations for medical purposes. These types of examinations involve man-made ionizing radiation, and the examination conditions are adjusted based on the principle of keeping exposure as low ...[Read More] Is Radiation Exposure from Medical Imaging Safe? Understanding Risks and Recommendations
Understanding the Differences in MRI Scans: Brain vs. Head and Neck
Differences in MRI Regions Hello, doctor. I looked up MRI examinations online, and I found that there are different prices for brain, head, and neck scans. Aren't the brain and head the same area? Why is there a difference? Additionally, I had a CT scan of the head ordered b...
Dr. Sun Shengyi Reply:
In MRI examinations of the head and neck, the scanning parameters and coil selection vary based on clinical needs related to the intracranial region (primarily the cerebrum and cerebellum), sinuses, pharynx, cervical spine, or vascular structures. It is not always possible to com...[Read More] Understanding the Differences in MRI Scans: Brain vs. Head and Neck
Understanding Health Insurance Coverage for MRI Scans in Taiwan
Health insurance reimbursement issues? Hello Doctor, I would like to ask again. If several tests have been conducted without identifying the cause, but the symptoms are very evident, and the hospital states that further MRI examinations must be paid out-of-pocket, I would like to...
Dr. Ye Weicheng Reply:
MRI is a high-cost examination that requires clinical symptoms or evidence that justify the need for the MRI scan before a clinician will agree to order it (otherwise, it may be rejected by the National Health Insurance Administration). Allowing patients to pay out-of-pocket firs...[Read More] Understanding Health Insurance Coverage for MRI Scans in Taiwan
Understanding X-Ray Radiation Dose: Clarifying Myocardial Perfusion Scans and Safety Tips
Re: X-ray Radiation Dose I am Mr. Li, who asked a question on November 7. Thank you very much for your response, doctor. I would like to ask again whether the 10 mSv radiation dose you mentioned refers specifically to the radiation dose from the myocardial perfusion scan, or is i...
Dr. Sun Shengyi Reply:
The estimated radiation dose of approximately 10 mSv is based on the cumulative dose from the examinations you have undergone over the past ten years, which is not considered a high dose. The greater concern is short-term exposure to high doses of radiation. Radiation effects can...[Read More] Understanding X-Ray Radiation Dose: Clarifying Myocardial Perfusion Scans and Safety Tips
Understanding X-Ray Radiation Exposure: Risks and Long-Term Effects
X-ray radiation dose I would like to ask the doctor: What is the approximate radiation dose from an abdominal X-ray? Between my twenties and thirties, I underwent more than ten chest X-rays and more than ten abdominal X-rays due to health check-ups and illnesses, as well as one r...
Dr. Sun Shengyi Reply:
The radiation dose from an abdominal X-ray is approximately 0.4-0.6 mSv (millisieverts), while a chest X-ray is only about 0.02 mSv. Myocardial perfusion scans are related to the duration that the isotopes remain in the body (which is only a few days), and their long-term effects...[Read More] Understanding X-Ray Radiation Exposure: Risks and Long-Term Effects
Understanding CT Scans: Radiation Risks and Safety for Patients
CT scan of the head Hello doctor, my mom fell off her bicycle this week and hit her head. The doctor performed a CT scan and said everything is fine. However, I would like to ask if my mom, who underwent radiation therapy two years ago, is at risk of excessive radiation exposure ...
Dr. Sun Shengyi Reply:
The radiation dose from a single head computed tomography (CT) scan is approximately 2.0 mSv (millisieverts), which is less than one-thousandth of the high doses used in typical radiation therapy. Therefore, the potential harm to a normal human body is minimal, and there is no ne...[Read More] Understanding CT Scans: Radiation Risks and Safety for Patients
Impact of 20 X-rays in Six Months: Health Risks and Leukemia Concerns
The impact of undergoing 20 X-rays in six months on the body? In September of this year, I underwent a small bowel barium X-ray due to persistent lower abdominal issues, which involved taking about a dozen images. Then, in mid-November, I had a urinary tract X-ray with contrast d...
Dr. Sun Shengyi Reply:
A standard X-ray exposure is approximately 0.02-0.5 mSv (millisieverts). To cause direct harm to the body, the exposure would need to be at least 100 mSv or more. The potential increase in the risk of leukemia is also extremely low, so there is no need to worry about the possible...[Read More] Impact of 20 X-rays in Six Months: Health Risks and Leukemia Concerns
Understanding Radiation Exposure: Air Travel and X-Ray Concerns
Radiation issues? I would like to ask the doctor: I traveled by plane from Taipei to New York round trip this August, and now I have abdominal pain and had an abdominal X-ray. Is the radiation dose from flying in such a short time combined with the X-ray exposure high? Does it ex...
Dr. Yang Jinghua Reply:
Dear Xiaoli, Thank you for your inquiry. Regarding the harm caused by exposure to ionizing radiation in the human body, it can be categorized into immediate tissue damage and subsequent potential effects. Based on the data you provided, no visible harm is expected. The potential...[Read More] Understanding Radiation Exposure: Air Travel and X-Ray Concerns
Can CT Scans Accurately Diagnose ENT and Brain Tumors?
Computed Tomography (CT) Scan Hello, if there is a suspicion of tumors related to the ear, nose, and throat, or deep-seated brain tumors such as pituitary adenomas or nasopharyngeal tumors, can a CT scan provide an accurate diagnosis? Thanks.
Dr. Ye Weicheng Reply:
Current multi-slice computed tomography (CT) can perform post-processing to generate images in axial, coronal, and sagittal planes. For pituitary or craniopharyngioma tumors, the administration of contrast agents during multi-slice CT can reveal the location, size, and shape of t...[Read More] Can CT Scans Accurately Diagnose ENT and Brain Tumors?
Accuracy of Gallium-67 Scans for Diagnosing Colorectal Cancer
Gallium-67 scanning Hello, doctor. Is the accuracy of Gallium-67 whole-body scanning high for diagnosing colorectal cancer? Can it detect polyps? Thank you. (I have had a low-grade fever for nearly a year, and the Gallium-67 scan is scheduled for January next year. Recently, I ha...
Dr. Sun Shengyi Reply:
Gallium-67 whole-body scans are not used to diagnose colorectal cancer, nor are they used to evaluate polyps. They are typically employed to investigate potential inflammatory lesions in the body due to prolonged unexplained fever. If there are concerns regarding colorectal tumor...[Read More] Accuracy of Gallium-67 Scans for Diagnosing Colorectal Cancer
Understanding Radiation Levels in FREEdom CT750 Scans: A Comparison
Computed Tomography (CT) Scan Hello, doctor. Previously, I inquired about the radiation dose of a standard CT scan, which is approximately 8 mSv for the abdomen and about 2 mSv for the head and neck. I heard that a certain hospital uses the FREEdom CT750, which reportedly has a l...
Dr. Sun Shengyi Reply:
The company's CT product (Discovery CT750 HD FREEdom Edition) utilizes a special technology called ASiR* (Adaptive Statistical Iterative Reconstruction) that maintains image quality while using a lower dose. It is claimed that this technology can reduce the dose by up to 50%...[Read More] Understanding Radiation Levels in FREEdom CT750 Scans: A Comparison
Understanding IVP Kidney Imaging: Radiation Concerns and Frequency
Intravenous Pyelogram (IVP) Hello, doctor. A few years ago, I had a urine test that showed trace blood (1+) and underwent renal imaging at the hospital. I remember having many X-rays taken, and the doctor said everything was normal. However, this year during my health check-up, I...
Dr. Yang Jinghua Reply:
Dear Mr. Xiaohong, Regarding the execution of medical imaging, it should be determined based on the needs of the patient's diagnosis and treatment. Physicians must rely on their professional judgment to conduct examinations before making accurate diagnoses and treatment pla...[Read More] Understanding IVP Kidney Imaging: Radiation Concerns and Frequency
Is CT Scan Radiation Safe for Young Children? Understanding Risks
Will young children be exposed to excessive radiation when undergoing a CT scan? Hello doctor, my son turned four today. He went to the hospital for an arrangement due to pectus excavatum, and he had an X-ray and a chest CT scan. I only found out afterward that the radiation expo...
Dr. Yang Jinghua Reply:
Dear Xiaoqi's Mom, Thank you for your inquiry. Medical imaging examinations assist clinicians in precise diagnosis and treatment. The amount of ionizing radiation exposure from these diagnostic tests is approximately equivalent to two years of natural background radiation. ...[Read More] Is CT Scan Radiation Safe for Young Children? Understanding Risks
Impact of Dental Metal on MRI Brain Imaging: What You Need to Know
MRI Metal Issues Hello, doctor. I need to undergo an MRI of the brain, but I recently had jaw surgery and have a fixed metal dental brace. I'm unsure if this will affect the clarity of the MRI images. I consulted with the imaging department, but they weren't very certai...
Dr. Ye Weicheng Reply:
Magnetic resonance imaging (MRI) utilizes a powerful magnetic field to produce images. Common artifacts caused by metallic objects include the creation of black spots or distortion of the images. However, the extent of interference with image quality depends on the type of materi...[Read More] Impact of Dental Metal on MRI Brain Imaging: What You Need to Know
Impact of UV Sterilizers on Fetal Health: Safety Guidelines for Expecting Mothers
The impact of ultraviolet (UV) dish sterilizers on fetuses? Hello doctor, I am currently pregnant and would like to ask if being close to a UV disinfection machine while it is in use, or opening the door during its operation, could affect the fetus? What distance would be conside...
Dr. Ye Weicheng Reply:
Ultraviolet (UV) radiation is electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays. The shorter the wavelength of electromagnetic waves, the higher their energy and greater their penetrating power. For example, X-rays can penetrate the huma...[Read More] Impact of UV Sterilizers on Fetal Health: Safety Guidelines for Expecting Mothers
Understanding Cumulative Radiation Dose from HRCT and X-rays
Regarding HRCT and the cumulative radiation dose I have received? Hello Dr. Yang, due to my autoimmune disease affecting my joints and asthma issues, this year I have undergone several imaging studies as arranged by my physician, including X-rays and a high-resolution computed to...
Dr. Yang Jinghua Reply:
Ms. Lee: Hello, I am pleased to answer your questions regarding radiation protection. Given that the examination protocols may vary slightly among hospitals, I will refer to the dose reference values published by the Atomic Energy Commission. For two chest computed tomography (CT...[Read More] Understanding Cumulative Radiation Dose from HRCT and X-rays
Radiology FAQ
| Contrast Agent | Ct Scan |
| Ct Scan Radiation | Magnetic Resonance Imaging |
| Mri | Mri Report |
| Radiation | Radiological Examination |
| X-Ray | X-Ray Examination |
| X-Ray Radiation |