Ultra-Low-Dose CT Scans May Help Early Detection Of Pneumonia

Updated Mar 19, 2025 | 09:20 AM IST

SummaryCT scans are the gold standard for detecting pneumonia but there are concerns regarding the risk posed by repeated exposure to radiation.
Ultra-Low-Dose CT Scans May Detect Pneumonia in At-Risk Patients

Credit: Canva

Low-dose CT chest scans could help detect pneumonia in at-risk patients while exposing them to only small amounts of radiation, a new study has found. The research, published in Radiology: Cardiothoracic Imaging, shows that ultra-low-dose scans can effectively detect pneumonia in patients with compromised immune systems, enabling doctors to treat the infection before it becomes life-threatening. According to the researchers, these scans expose patients to just 2% of the radiation dose used in a standard CT scan.

"This study paves the way for safer, AI-driven imaging that reduces radiation exposure while preserving diagnostic accuracy,” lead researcher Dr Maximiliano Klug, a radiologist with the Sheba Medical Center in Ramat Gan, Israel, said in a news release. He added that CT scans are the gold standard for detecting pneumonia but there are concerns regarding the risk posed by repeated exposure to radiation. There is a solution- ultra-low-dose CT scan. However, the problem is that these scans can be grainy and hard to read, researchers said.

Study Gives Solution To This

To overcome that, Klug's team developed an AI program that could help "de-noise" low-dose scans, making them sharper and easier to read. Between September 2020 and December 2022, 54 patients with compromised immune systems who had fevers underwent a pair of chest CT scans -- a normal dose scan and an ultra-low-dose scan. The AI program cleaned up the low-dose scan, and then both sets of images were given to a pair of radiologists for assessment. Radiologists had 100% accuracy in detecting pneumonia and other lung problems with the AI-cleaned low-dose scans, but 91% to 98% accuracy in examining the scans that hadn’t been improved through AI, results show.

"This pilot study identified infection with a fraction of the radiation dose," Klug said. "This approach could drive larger studies and ultimately reshape clinical guidelines, making denoised ultra-low dose CT the new standard for young immunocompromised patients.

How Can You Detect Pneumonia?

Pneumonia is a lung infection that causes the air sacs in the lungs to fill with fluid or pus and can be caused by bacteria, viruses, or fungi. The symptoms can range from milk to severe, which includes:

Coughing with or without cough

Fever

Chills

Trouble breathing

Chest pain, especially when breathing deeply or coughing

Sweating or chills

Rapid heart rate

Loss of appetite

Bluish skin, lips, and nails

Confusion.

How to detect Pneumonia in coughing newborns and toddlers?

Pneumonia can severely affect newborns and young children as their lungs are comparatively more sensitive. As per Dr Goyal, young children can cough for various reasons including seasonal infections and tonsillitis, which is very common in this age group. But if they look visibly irritable and have poor sleep patterns, then parents must reach out to an expert. "I am not saying that parents must visit a hospital but any local paediatrician would be able to detect pneumonia in your kid.

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Quit Smoking Years Ago? New Study Says You May Still Be At The Risk Of Lung Disease

Updated Jul 27, 2026 | 03:00 PM IST

SummaryEven though quitting smoking helps reverse the damages, a recent study has found that former smokers may still be at risk of various lung diseases.
Quit Smoking Years Ago? New Study Says You May Still Be At The Risk Of Lung Disease

Credit: AI

Quitting smoking remains one of the best decisions for your health. But new research suggests that even years after your last cigarette, your lungs may continue to carry the harmful effects that increase the risk of chronic lung disease.

A new study by McGill University, published in the journal Translational Research, finds why former smokers remain at high risk to lung diseases even after quitting.

By analysing lung cells closely, scientists found that even though some damage due to smoking heals over time, other damages persist, leaving ex-smokers at a higher risk of conditions like chronic obstructive pulmonary disease (COPD) and lung cancer.

What Did The Study Find?

The study was conducted on more than 100,000 individual lung cells collected from 21 people, including nine people who had never smoked, five active smokers, and seven former smokers.

Using single-cell RNA sequencing, researchers examined molecular activity across more than 40 different lung cell types, creating one of the most comprehensive maps of how smoking and smoking cessation affect the lungs at the cellular level.

Their findings revealed that long-term lung recovery is not uniform. While some lung cells gradually regained healthier patterns after smoking cessation, others continued to show long-term molecular changes affecting tissues, immune responses, blood vessel function, and the overall lung health.

Perhaps the most surprising finding was that some cells in ex-smokers showed unique molecular markers that were not seen in active smoker and participants who never smoked, suggesting quitting smoking creates its own biological impact.

Also read: Even Light Exercise Could Help People With COPD Live Longer, Study Finds

Why Does Lung Disease Risk Persist After Quitting?

Scientists have long known that the risk of lung cancer and COPD declines after quitting smoking, but it never completely returns to the same level as seen in people who have never touched a cigarette.

Smoking damages DNA, alters gene activity, triggers chronic inflammation and injures delicate lung tissues. While the body repairs some of this damage after the smoker quits, certain cellular changes become persistent.

These lingering molecular alterations could continue influencing how lung tissue responds to injury, infections and aging.

Senior author Professor Carolyn Baglole, from McGill University's Department of Pharmacology and Therapeutics, said, "Current smokers have the highest risk of deadly diseases like lung cancer, but former smokers still face a higher risk than people who never smoked. Despite more than a century of research on smoking, we don't fully understand why."

She added, "Our findings show that while some damage appears reversible, other changes persist long after people stop smoking."

First author Nicole Heimbach, a doctoral student at McGill University, said, "These findings are an important step toward understanding what damage caused by smoking can heal and what may be permanent. By knowing what damage remains after quitting, we can better understand how smoking-related diseases develop and how to treat them."

Also read: Could Wildfire Smoke Trigger Your Migraine? Latest Study Finds A Strong Link

Thinking Of Switching To Vaping Instead Of Quitting Cigarettes?

Instead of quitting smoking, if you are thinking of switching to vaping, think again. According to a new study, vape users presented reduced fitness and impaired blood vessel function similar to traditional cigarette smokers.

The research, published in the peer-reviewed journal ERJ Open Research, compared healthy adults aged 18 to 30 and found that both regular vapers and smokers had around 15% lower exercise capacity than people who had never smoked or vaped.

This suggests that electronic cigarettes like vapes are not lesser of two evils.

The researchers, however, caution that the study does not suggest that vaping is equally harmful as smoking in every respect.

Traditional cigarettes still strongly remain linked to major disorders like cancer, chronic obstructive pulmonary disease (COPD), and many other life-threatening illnesses.

But the new study indicates that when it comes to cardiovascular fitness, breathing efficiency, lung function and blood vessel health in young adults, vaping may offer far less protection.

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Think Marijuana Helps Relax? New Study Links Cannabis With Higher Levels Of Stress Hormone

Updated Jul 27, 2026 | 12:30 PM IST

SummaryA new study has debunked the myth cannabis helps reduce stress. It suggested that frequent marijuana users may face higher levels of stress hormone in the long run.
Think Marijuana Helps Relax? New Study Links Cannabis With Higher Levels Of Stress Hormone

Credit: AI

People who use cannabis frequently believing it relieves stress are about to be proven wrong. A new study debunked the myth that marijuana helps alleviate stress levels.

In fact, researchers recently found that frequent cannabis users may face the risk of higher levels of cortisol, body's stress hormone.

While the study does not prove that marijuana causes chronic stress, they raise important questions about how regular cannabis use affects long-term mental and physical health.

What Did The Study Find?

The study, conducted by researchers at Oregon State University and published in the journal Cannabis, examined 82 young adults, including 39 frequent cannabis users and 43 non-users.

Participants provided saliva samples immediately after waking and again 30 minutes later, allowing researchers to measure the cortisol awakening response (CAR), a natural surge in cortisol that prepares the body for the day.

The researchers found that frequent cannabis users had higher cortisol levels immediately upon waking compared to non-users. However, both groups showed a similar cortisol increase during the first 30 minutes after waking.

This suggests that cannabis users started the day with an already elevated stress hormone level rather than having an exaggerated morning cortisol surge.

Also read: 10 Odd Signs Of Stress That You Thought You Knew But Don't

Cortisol Isn't Just The 'Stress Hormone'

Cortisol, often called the stress hormone, plays several essential roles in the body. It helps regulate:

  • Blood pressure
  • Blood sugar
  • Metabolism
  • Immune function
  • Body's response to physical and emotional stress

A temporary rise in cortisol is normal and even beneficial. But, chronically elevated cortisol has been linked to anxiety, depression, cardiovascular disease, metabolic disorders, and impaired immune function.

Why People Use Cannabis For Stress?

Many users experience short-term relaxation after consuming marijuana, particularly due to THC's effects on the brain's cannabinoid receptors.

However, researchers say repeated exposure may gradually alter the hypothalamic-pituitary-adrenal (HPA) axis, the body's central stress-response network.

Over time, this could interfere with normal stress regulation, potentially creating a cycle where people increasingly rely on cannabis to cope with stress while their biological stress system becomes dysregulated.

However, researchers clarify that the study does not establish that frequent marijuana use directly causes increase in cortisol.

Also read: Could Wildfire Smoke Trigger Your Migraine? Latest Study Finds A Strong Link

The findings add to a growing body of evidence suggesting that heavy cannabis consumption may have complex effects on mental health. Recent research has linked it with:

  • Increased risk of anxiety and depressive symptoms
  • Higher likelihood of cannabis use disorder
  • Greater risk of psychosis in susceptible individuals
  • Cognitive problems, including impaired memory with long-term heavy use
  • Experts note that these risks appear to increase with more frequent use, higher THC potency, and younger age at first use.

Many people use marijuana to unwind after a stressful day, but this study suggests that frequent cannabis use may be associated with higher baseline stress hormone levels upon waking. This could affect one's day-to-day quality of life.

As cannabis use continues to rise worldwide, researchers say understanding its long-term effects on mental health and the body's stress response will be increasingly important, especially to bust common myths associated to its use.

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Can Long COVID Be Prevented Before It Starts? Study Suggests Early Paxlovid May Help

Updated Jul 27, 2026 | 10:55 AM IST

SummaryPaxlovid combines two antiviral medicines—nirmatrelvir and ritonavir—and remains one of the most effective outpatient treatments for people at high risk of severe COVID-19.
Can Long COVID Be Prevented Before It Starts? Study Suggests Early Paxlovid May Help

Credit: Reuters

Long COVID—a debilitating condition that can persist for months or even years after a SARS-CoV-2 infection—may be preventable if treatment begins early, according to a new study.

Long COVID is an infection-associated chronic condition marked by fatigue, cognitive impairment, exercise intolerance, and multisystem dysfunction. It has affected an estimated 400 million people worldwide and continues to have significant health, social, and economic consequences. Despite the ongoing risk, prevention strategies have received relatively little attention.

Now, a landmark randomized trial, published in The Lancet, provides some of the strongest evidence to date that early treatment with the antiviral drug Paxlovid (nirmatrelvir–ritonavir) can reduce the risk of developing Long COVID by 40%. The treatment was effective when started during the acute phase of COVID-19.

“The message is profound: what happens in the first few days of COVID-19 may determine health for months—or even years,” said researchers from the University of California, San Francisco.

The researchers added that preventing Long COVID "may become the next frontier in COVID care."

Paxlovid combines two antiviral medicines—nirmatrelvir and ritonavir—and remains one of the most effective outpatient treatments for people at high risk of severe COVID-19.

What Did the Study Find?

Researchers conducted a randomized controlled trial in Norway involving patients with acute COVID-19. They found that a five-day course of nirmatrelvir–ritonavir significantly reduced the risk of Long COVID three months after infection.

For the study, Long COVID was defined as patient-reported fatigue, shortness of breath (dyspnea), or cognitive symptoms during the post-acute phase.

The findings provide some of the first randomized trial evidence that antiviral treatment during acute infection can lower the risk of Long COVID, supporting earlier observational studies.

Importantly, the trial was conducted during the circulation of successive Omicron subvariants, from XBB to LP.8.1, making the findings relevant to the current phase of the pandemic.

A notable finding was the high rate of Long COVID among participants. In the placebo group, 33 of 77 participants (43%) met the criteria for Long COVID despite widespread vaccine-derived immunity. While vaccination offers partial protection, the study suggests a substantial risk still remains.

Why Might Early Treatment Help?

The researchers suggest several biological mechanisms that may explain the protective effect of early antiviral treatment:

Reducing viral replication early may lower peak viral load and shorten viral shedding, both of which have been linked to Long COVID.

Early treatment may limit immune dysregulation, allowing the body's antiviral immune response to control the virus more effectively.

Treating the infection during its acute phase may prevent or reduce processes associated with Long COVID, including persistent SARS-CoV-2 infection, herpesvirus reactivation, and immune dysfunction.

The trial suggests that early viral replication may trigger "self-sustaining or persistent harmful biological processes" that contribute to Long COVID.

"Defining these relationships could yield predictive biomarkers and more targeted prevention strategies," the researchers noted.

Are There Any Side Effects of Paxlovid?

The researchers noted that nirmatrelvir–ritonavir commonly causes dysgeusia (altered taste), which may have influenced how some participants perceived their treatment and reported symptoms. They said future studies should evaluate this possibility and investigate antivirals with less distinctive side-effect profiles.

Other common side effects include diarrhea and high blood pressure (hypertension).

According to the US Food and Drug Administration (FDA), Paxlovid can also interact with several commonly used medications, including statins. Patients should discuss all prescription drugs, over-the-counter medicines, and supplements they are taking with their healthcare provider before starting treatment.

While the current study assessed participants three months after infection, the researchers said longer follow-up is needed to determine whether early antiviral treatment provides durable protection against Long COVID or simply accelerates recovery from acute illness. They also emphasized the need for larger studies to evaluate its impact on severe, disabling forms of Long COVID.

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