Not so long ago, if a doctor needed to know what was happening inside your body, the options were limited — a basic X-ray, an exploratory surgery, or educated guesswork. Today, a radiologist can map your brain’s blood vessels, detect a cancer smaller than a pea, or watch your heart metabolizing sugar in near real time — all without making a single incision.
The first medical X-ray appeared in 1895. For decades, imaging largely meant detecting fractures or large abnormalities. Today, radiology guides emergency care, cancer treatment, stroke therapy, cardiac management, and preventive medicine. Modern diagnostic imaging has transformed medicine in ways that would have seemed like science fiction to physicians just a few generations ago.
Modern imaging falls into three broad categories: structural imaging — what tissues look like, vascular imaging — how blood flows, and functional imaging — how cells behave metabolically. Here’s a plain-language guide to the big three: MRI/MRA, CT/CTA, and PET scans — what they are, how they work, and why they matter.
MRI and MRA: Magnets and Radio Waves
The MRI — magnetic resonance imaging — is one of the most versatile tools in modern medicine, and it works without a single ray of radiation. An MRI passes an electric current through coiled wires to create a temporary magnetic field in your body. A transmitter and receiver then send and receive radio waves, and a computer uses those signals to construct detailed digital images of whatever area is being scanned. Think of it as a very sophisticated tuning fork: it causes hydrogen atoms in your body’s water molecules to briefly align, then releases them — and the energy they emit on the way back creates the image. Because different tissues relax at different rates, MRI can distinguish gray matter from white matter in the brain, normal from inflamed or cancerous tissue, and ligament from muscle with impressive contrast.
The result is exceptional detail, especially for soft tissue. MRI scans take much clearer pictures of your brain, spinal cord, nerves, muscles, ligaments, and tendons than regular X-rays and CT scans. That’s why your orthopedic surgeon orders one when your knee goes sideways, and why neurologists reach for it when they suspect a stroke or multiple sclerosis.
MRA — magnetic resonance angiography — is MRI’s cousin, using the same magnetic technology but focused specifically on blood vessels. It lets physicians map arteries and veins in remarkable detail, identifying narrowing (stenosis), bulges (aneurysms), or blockages (occlusions) without the need for invasive catheterization. If your doctor suspects a blockage in the blood vessels feeding your brain or kidneys, an MRA can reveal it clearly. A contrast dye is sometimes injected to make vessels stand out even more sharply.
The main trade-offs with MRI are time and noise — scans generally take between 30 to 50 minutes, and the machine produces the kind of clanging racket that makes earplugs standard issue. People with certain metal implants or severe claustrophobia can’t always use it, which is where CT steps in.
CT and CTA: X-Rays, Upgraded
The CT scan — computed tomography — takes the familiar chest X-ray and turns it into something far more powerful. A CT scan takes multiple X-ray images from different angles rotating around the body, separates them by depth then processes them by computer to create cross-sectional views — essentially a detailed 3D picture rather than a flat 2D image. Think of slicing a loaf of bread: instead of seeing only the crust, you can examine every slice.
A CT shows more detail than a standard X-ray and is used to diagnose cancer, heart disease, injuries from trauma, and musculoskeletal disorders — it’s one of the most common imaging tests used today. Emergency departments rely on CT heavily because it’s fast, often completed in 10 to 15 minutes, and can quickly identify life-threatening conditions like internal bleeding or pulmonary embolism.
CTA — CT angiography — adds an injected contrast dye to the mix, allowing physicians to see blood vessels with high clarity. Contrasting agents help show various structures of the body more clearly, making CTA the go-to test for evaluating coronary arteries, aortic aneurysms, and vascular disease throughout the body. Unlike MRA, it’s faster and more widely available, though it does involve a dose of radiation — something physicians weigh carefully against the diagnostic benefit.
PET Scan: When Function Matters More Than Form
If MRI and CT show you the structure of the body, the PET scan — positron emission tomography — shows you what’s happening inside it. This is a fundamentally different question, and the technology reflects that.
A PET scan is used to see metabolism and chemical activity within your body. It can detect abnormal changes before structural changes occur — meaning it can detect cancer before a tumor is large enough to be seen on a CT or MRI. That’s a remarkable capability. The scan works by injecting a small amount of a radioactive tracer — most commonly a form of glucose — into your bloodstream. Diseased cells, particularly cancer cells, absorb more of the radiotracer than healthy ones do. Active cells consume glucose. Cancer cells, inflamed tissue, and active brain regions often use more glucose than surrounding tissue. These are called “hot spots,” and the PET scanner detects this radiation to produce images of affected tissue.
Beyond cancer, PET scans are invaluable in cardiology — showing whether heart muscle is still alive after a heart attack — and in neurology, helping diagnose Alzheimer’s disease, epilepsy, and brain tumors by revealing abnormal patterns of brain activity.
The trade-off is resolution. The image resolution of nuclear medicine images may not be as high as that of CT or MRI, which is why PET is rarely used alone today. Combined PET/CT scanners perform almost all PET scans today , marrying metabolic information with anatomical precision. Hybrid PET/MRI scanners are also emerging though not yet in widespread use. They are particularly valuable for soft-tissue cancers of the brain, liver, and pelvis.
How They Compare — and Why It Matters
The simplest way to think about these three technologies is this: CT shows shape and structure quickly, with emphasis on bone and dense tissue; MRI shows soft tissue in extraordinary detail without radiation; and PET shows function and cellular activity that neither of the others can see directly.
A patient with suspected cancer might undergo a CT scan to identify the location of a mass, followed by a PET to determine its metabolic activity, and then an MRI to map its relationship to critical soft tissues. Used together, these tools give physicians a picture of disease that is more complete than any single test could provide.
The value to modern medicine is difficult to overstate. These technologies allow doctors to diagnose conditions earlier, stage cancers more accurately, guide surgical planning, and monitor how well treatments are working — all without exploratory surgery. Survival rates for many cancers have improved substantially in part because imaging lets us find disease when it’s still manageable.
The era when medicine was largely guesswork about what lay beneath the skin is over. Today, radiologists are, in a very real sense, reading the body like an open book.
Illustration generated by author using ChatGPT.
Sources:
UNC Health Appalachian — MRI, CT, and PET Scan Comparison: https://www.unchealthappalachian.org/blog/2024/comparing-mri-ct-and-pet-scans-how-they-work-and-when-theyre-use/
WashU Mallinckrodt Institute of Radiology — Differences Between CT, MRI, and PET: https://www.mir.wustl.edu/do-you-know-the-differences-between-a-ct-mri-and-pet-scan/
Cleveland Clinic — PET Scan Overview: https://my.clevelandclinic.org/health/diagnostics/10123-pet-scan
RadiologyInfo.org — PET/CT: https://www.radiologyinfo.org/en/info/pet
Open MedScience — CT, MRI, and PET Differences: https://openmedscience.com/ct-mri-and-pet-scanners-unravelling-the-differences-in-modern-medical-imaging/
Healthline — MRI vs. PET Scan: https://www.healthline.com/health/mri-vs-pet-scan
Revere Health — MRI, CT, and PET Explained: https://reverehealth.com/live-better/mri-ct-pet/
Russel Vought and the War on the Environment
By John Turley
On February 16, 2026
In Commentary, History, Politics, Science
Recently, there’s been a a lot of attention given to RFK Jr. and his war on vaccines. More potentially devastating than that is Russel Vought and his war on environmental science.
Russell Vought hasn’t exactly been working in the shadows. As the director of the Office of Management and Budget since February 2025, he’s been methodically implementing what he outlined years earlier in Project 2025—a blueprint that treats climate science not as settled fact, but as what he calls “climate fanaticism.” The result is undeniably the most aggressive dismantling of environmental protections in American history.
The Man Behind the Plan
Vought’s resume tells you everything you need to know about his approach. He served as OMB director during Trump’s first term, wrote a key chapter of Project 2025 focusing on consolidating presidential power, and has openly stated his goal is to make federal bureaucrats feel “traumatized” when they come to work. His philosophy on climate policy specifically? He’s called climate change a side effect of building the modern world—something to manage through deregulation rather than prevention.
Attacking the Foundation: The Endangerment Finding
The centerpiece of Vought’s climate strategy targets what EPA Administrator Lee Zeldin has called “the holy grail of the climate change religion”—the 2009 Endangerment Finding. This Obama-era scientific determination concluded that six greenhouse gases (carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride) endanger public health and welfare. It sounds technical, but it’s the legal foundation for virtually every federal climate regulation enacted over the past fifteen years.
Just last week EPA Administrator Zeldin announced that the Trump administration has repealed this finding. This action strips EPA’s authority to regulate greenhouse gas emissions under the Clean Air Act—meaning no more federal limits on power plant emissions, no vehicle fuel economy standards tied to climate concerns, and no requirement for industries to measure or report their emissions. White House press secretary Karoline Leavitt said this action “will be the largest deregulatory action in American history.”
More than 1,000 scientists warned Zeldin not to take this step, and the Environmental Protection Network cautioned last year that repealing the finding would cause “tens of thousands of additional premature deaths due to pollution exposure” and would spark “accelerated climate destabilization.” Abigail Dillen president of the nonprofit law firm Earthjustice said “there is no way to reconcile EPA’s decision with the law, the science and the reality of the disasters that are hitting us harder every year.” She further said they expect to see the Trump administration in court. Obviously, the science is less important to Trump, Zeldin and Vought than the politics.
The Thirty-One Targets
In March 2025, Zeldin announced what he proudly called “the greatest day of deregulation in American history”—a plan to roll back or reconsider 31 key environmental rules covering everything from clean air to water quality. The list reads like a regulatory hit parade, including vehicle emission standards (designed to encourage electric vehicles), power plant pollution limits, methane regulations for oil and gas operations, and even particulate matter standards that protect against respiratory disease.
The vehicle standards are particularly revealing. The transportation sector is America’s largest source of greenhouse gas emissions, and the Biden-era rules were crafted to nudge automakers toward producing more electric vehicles. At Vought’s direction, the EPA is now reconsidering these, with Zeldin arguing they “regulate out of existence” segments of the economy and cost Americans “a lot of money.”
Gutting the Science Infrastructure
Vought’s agenda extends beyond specific regulations to the institutions that produce climate science itself. In Project 2025, he proposed abolishing the Office of Domestic Climate Policy and suggested the president should refuse to accept federal scientific research like the U.S. National Climate Assessment (NCA). The NCA, published every few years, involves hundreds of scientists examining how climate change is transforming the United States—research that informs everything from building codes to insurance policies.
According to reporting from E&E News in January, Vought wants the White House to exert tighter control over the next NCA, potentially elevating perspectives from climate deniers and industry representatives while excluding contributions made during the Biden administration. This is a plan that has been in the works for years. Vought reportedly participated in a White House meeting during Trump’s first term where officials discussed firing the scientists working on the assessment.
The National Oceanic and Atmospheric Administration (NOAA) has also been targeted. In February 2025, about 800 NOAA employees—responsible for weather forecasting, climate monitoring, fisheries management, and marine research were fired. Project 2025 had proposed breaking up NOAA entirely, and concerned staff members have already begun a scramble to preserve massive amounts of climate data in case the agency is dismantled.
Budget Cuts as Policy
Vought’s Center for Renewing America has proposed eliminating the Department of Energy’s Office of Energy Efficiency and Renewable Energy, the EPA’s environmental justice fund, and the Low Income Home Energy Assistance Program. During the first Trump administration, Vought oversaw budgets proposing EPA cuts as steep as 31%—reducing the agency to funding levels not seen in decades. In a 2023 speech, he explained the logic bluntly: “We want their funding to be shut down so that the EPA can’t do all of the rules against our energy industry because they have no bandwidth financially to do so.”
This isn’t just about climate, it is also about fairness and the recognition that environmental policies have had a predominately negative effect on low income areas. EPA has cancelled 400 environmental justice grants, closed environmental justice offices at all 10 regional offices, and put the director of the $27 billion Greenhouse Gas Reduction Fund on administrative leave. The fund had been financing local economic development projects aimed at lowering energy prices and reducing emissions.
Eliminating Climate Considerations from Government
Perhaps more insidious than the high-profile rollbacks are the procedural changes that make climate considerations disappear from federal decision-making. In February, Jeffrey Clark—acting administrator of the Office of Information and Regulatory Affairs (OIRA) under Vought’s OMB—directed federal agencies to stop using the “social cost of carbon” in their analyses. This metric calculates the dollar value of damage caused by one ton of carbon pollution, allowing agencies to accurately assess whether regulations produce net benefits or defects for society.
Vought has also directed agencies to establish sunset dates for environmental regulations—essentially automatic expiration dates after which rules stop being enforced unless renewed. For existing regulations, the sunset comes after one year; for new ones, within five years. The stated goal is forcing agencies to continuously justify their rules, but the practical effect is creating a perpetual cycle of regulatory uncertainty.
The Real-World Stakes
The timing of these rollbacks offers a grim irony. As Vought was pushing to weaken the National Climate Assessment in January 2025, the Eaton and Palisades fires were devastating Los Angeles—exactly the type of climate-intensified disaster the assessment is designed to help communities prepare for. The administration’s response? Energy Secretary Chris Wright described climate change as “a side effect of building the modern world” at an industry conference.
An analysis by Energy Innovation, a nonpartisan think tank, found that Project 2025’s proposals to gut federal policies encouraging renewable electricity and electric vehicles would increase U.S. household spending on fuel and utilities by about $240 per year over the next five years. That’s before accounting for the health costs of increased air pollution or the economic damage from unmitigated climate change.
Environmental groups have vowed to challenge these changes in court, and the legal battles will likely stretch on for years. The D.C. Circuit Court of Appeals will hear many cases initially, though the Supreme Court will probably issue final decisions. Legal experts note that while Trump’s EPA moved with unprecedented speed on proposals in 2025, finalizing these rules through the required regulatory process will take much longer. As of December, none of the major climate rule repeals had been submitted to OMB for final review, partly due to what EPA called a 43-day government shutdown (which EPA blamed on Democrats, though the characterization is widely disputed).
What Makes This Different
Previous administrations have certainly rolled back environmental regulations, but Vought’s approach differs in both scope and philosophy. Rather than tweaking specific rules or relaxing enforcement, he’s systematically attacking the scientific and legal foundations that make climate regulation possible. It’s the difference between turning down the thermostat and ripping out the entire heating system.
The Environmental Defense Fund, which rarely comments on political appointees, strongly opposed Vought’s confirmation, with Executive Director Amanda Leland stating: “Russ Vought has made clear his contempt for the people working every day to ensure their fellow Americans have clean air, clean water and a safer climate.”
Looking Forward
Whether Vought’s vision becomes permanent depends largely on how courts rule on these changes. The 2007 Supreme Court decision in Massachusetts v. EPA established that the agency has authority to regulate greenhouse gases as air pollutants under the Clean Air Act—the very authority Vought is now trying to eliminate. Overturning established precedent is difficult, though the current Supreme Court’s composition makes the outcome possible, if not likely.
What we’re witnessing is essentially a test of whether one administration can permanently disable the federal government’s capacity to address climate change, or if these changes represent a temporary setback that future administrations can reverse. The stakes couldn’t be higher: atmospheric CO2 concentrations continue rising, global temperatures are breaking records, and climate-related disasters are becoming more frequent and severe. Nothing less than the future of our way of life is at stake. We must take action now.
Full disclosure: my undergraduate degree is in meteorology, but I would never call myself a meteorologist since I have never worked in the field. But I still maintain an interest, from both a meteorological and a medical perspective. The Grump Doc is never lacking in opinions.
Illustration generated by author using Midjourney.
Sources:
Lisa Friedman and Maxine Joselow, “Trump Allies Near ‘Total Victory’ in Wiping Out U.S. Climate Regulation,” New York Times, Feb. 9, 2026.[nytimes +1]
Lisa Friedman, “The Conservative Activists Behind One of Trump’s Biggest Climate Moves,” New York Times, Feb. 10, 2026.[nytimes +1]
Bob Sussman, “The Anti-Climate Fanaticism of the Second Trump Term (Part 1: The Purge of Climate from All Federal Programs),” Environmental Law Institute, May 7, 2025.[eli]
U.S. Environmental Protection Agency, “Trump EPA Kicks Off Formal Reconsideration of Endangerment Finding,” EPA News Release, Mar. 13, 2025.[epa]
Trump’s Climate and Clean Energy Rollback Tracker, Act On Climate/NRDC coalition, updated Jan. 11, 2026.[actonclimate]
“Trump to Repeal Landmark Climate Finding in Huge Regulatory Rollback,” Wall Street Journal, Feb. 9, 2026.[wsj]
Valerie Volcovici, “Trump Set to Repeal Landmark Climate Finding in Huge Regulatory Rollback,” Reuters, Feb. 9, 2026.[reuters]
Alex Guillén, “Trump EPA to Take Its Biggest Swing Yet Against Climate Change Rules,” Politico, Feb. 10, 2026.[politico]
“EPA Urges White House to Strike Down Landmark Climate Finding,” Washington Post, Feb. 26, 2025.[washingtonpost]
“Trump Allies Near ‘Total Victory’ in Wiping Out U.S. Climate Regulation,” Seattle Times reprint, Feb. 10, 2026.[seattletimes]
“Trump Wants to Dismantle Key Climate Research Hub in Colorado,” Earth.org, Dec. 17, 2025.[earth]
“Vought Says National Science Foundation to Break Up Federal Climate Research Center,” The Hill, Dec. 17, 2025.[thehill]
Rachel Cleetus, “One Year of the Trump Administration’s All-Out Assault on Climate and Clean Energy,” Union of Concerned Scientists, Jan. 13, 2026.[ucs]
Environmental Protection Network, “Environmental Protection Network Speaks Out Against Vought Cabinet Consideration,” Nov. 20, 2024.[environmentalprotectionnetwork]
“From Disavowal to Delivery: The Trump Administration’s Rapid Implementation of Project 2025 on Public Lands,” Center for Western Priorities, Jan. 28, 2026.[westernpriorities]
“Russ Vought Nominated for Office of Management and Budget Director,” Environmental Defense Fund statement, Mar. 6, 2025.[edf]
“Project 2025,” Heritage Foundation/Project 2025 backgrounder (as summarized in the Project 2025 Wikipedia entry).[wikipedia]
“EPA to repeal finding that serves as basis for climate change,” The Associated Press, Matthew Daly
https://vitalsigns.edf.org/story/trump-nominee-and-project-2025-architect-russell-vought-has-drastic-plans-reshape-america
https://en.wikipedia.org/wiki/Russell_Vought
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https://www.scientificamerican.com/article/trump-epa-unveils-aggressive-plans-to-dismantle-climate-regulation/
https://www.bloomberg.com/news/articles/2026-02-10/trump-s-epa-to-scrap-landmark-emissions-policy-in-major-rollback