Key takeaways

  • DEXA (Dual-Energy X-ray Absorptiometry) is the standard test for diagnosing osteoporosis early. It is quick (about 15–20 minutes), painless, and uses a very low dose of radiation.
  • Routine screening is advised for all women aged 65 and above, and earlier (from age 50) for postmenopausal women with risk factors such as a prior fragility fracture, steroid use, smoking, low body weight, or premature menopause.
  • Your T-score classifies bone health: −1.0 or higher is normal, between −1.0 and −2.5 is osteopenia (low bone mass), and −2.5 or lower is osteoporosis.
  • A low Z-score in a younger woman is a signal to look for a treatable cause — vitamin D deficiency, thyroid or parathyroid disease, celiac disease, or steroid use.
  • The FRAX online calculator turns your score into a 10-year fracture risk and helps decide whether medication is needed, especially in the osteopenia grey zone.
  • A DEXA costs roughly Rs 1,500–Rs 4,500 in private centres and is far cheaper or free at major government teaching hospitals.

What a DEXA Scan Actually Measures

DEXA stands for Dual-Energy X-ray Absorptiometry. It uses two very low-dose X-ray beams to estimate how much mineral — mainly calcium — is packed into a section of bone. For osteoporosis assessment, the key sites are the lumbar spine and the hip (especially the femoral neck and total hip). These are not random choices: vertebral and hip fractures are the ones doctors worry about most because they steal mobility, independence, and sometimes survival in older adults.

This is different from the ordinary X-ray most families know after a fall. A plain X-ray is good at showing a bone that is already broken or very thinned. DEXA is designed to catch earlier, subtler bone loss. It gives a quantified bone mineral density value and compares it against reference populations — which is why the report can classify your bone health far more precisely than a plain radiograph.

A DEXA report is only useful if you understand what the numbers represent. The T-score compares your bone density with a healthy young adult at peak bone mass. The Z-score compares you with people of your own age and sex. That distinction matters: a postmenopausal woman with a low T-score may have age-related loss, while a younger woman with a very low Z-score raises the question of a secondary cause such as vitamin D deficiency, an overactive thyroid, or long-term steroid use.

The India context matters more than many families realise. Indian bone-density datasets from tertiary centres have repeatedly shown that Indian women are not protected by ethnicity, while vitamin D deficiency is extremely common in urban and semi-urban populations. Add lower dietary calcium, indoor work, clothing that limits sun exposure, repeated pregnancies without nutrition recovery, and screening that gets delayed because women put family expenses first — and the pattern clinicians see daily is a fracture or back pain becoming the first real warning.

It is also worth knowing what DEXA does not measure. It does not assess muscle strength, balance, fall risk, your vitamin D level, or pain. A woman can have body aches from low vitamin D with a near-normal scan, or a very low T-score with no pain at all. That is why a good report sits inside a wider clinical assessment instead of becoming the only number everyone fixates on.

When Women in India Should Get Screened

The broad rule is simple: women aged 65 and above should have routine bone density assessment, even if they feel completely well. Bone loss speeds up after menopause as oestrogen falls, and most women have no symptoms until a low-trauma fracture occurs. In India, where height loss, chronic back pain, or a bent posture are often dismissed as "just age," waiting for symptoms misses the chance to prevent vertebral collapse or a hip fracture.

Screen earlier — from age 50 — in postmenopausal women who have risk factors, including:

  • A prior fragility fracture (wrist, spine, shoulder, or hip from a minor fall)
  • Long-term steroid (glucocorticoid) use
  • Low body weight or a low BMI
  • Smoking or high alcohol intake
  • A parent who had a hip fracture
  • Rheumatoid arthritis or other inflammatory disease
  • Premature or surgical menopause
  • Malabsorption (such as celiac disease), chronic kidney disease, or an overactive thyroid

Younger women do not need routine screening simply because they are worried, but a DEXA is justified when risk factors cluster — for example, women on glucocorticoids for Lupus (SLE) in Indian Women: Diagnosis, Treatment, Pregnancy, rheumatoid arthritis, or asthma; women with prolonged amenorrhoea or an eating disorder; or those who have already had a low-trauma fracture. A 42-year-old who reached menopause after chemotherapy, avoids sunlight, eats little calcium, and takes steroids for an autoimmune disease is not "too young" — she is exactly who benefits from early testing.

Family dynamics shape who gets tested. Many women still hear, "Why do you need this scan if you can walk fine?" or "Take calcium tablets first." But screening is most valuable before the first major fracture, not after a hospital admission. A practical way to decide: ask whether the result would change management in the next few years. If yes — a woman starting long-term steroids, an oncology survivor with treatment-induced menopause, or someone whose mother became bedridden after a hip fracture — the scan is worth discussing. If you are also weighing hormone therapy or contraception around this stage, see our guides on hormone replacement therapy options and cost and contraception during perimenopause.

How to Prepare Before the Scan

Preparation is easy, but a few small details affect report quality. The most standard advice is to avoid calcium supplements for about 24 hours before the test — including over-the-counter tablets such as Shelcal 500, Shelcal HD, or Cipcal. One tablet will not invalidate the scan, but recent calcium intake can occasionally interfere with the reading, especially in centres that follow a strict protocol. Weekly vitamin D sachets such as Calcirol 60K or Uprise-D3 60K are not the main concern on the day; the key instruction is about calcium tablets, not fasting.

You usually need to postpone the scan if you have recently had a contrast-based imaging test — especially a barium study or some nuclear medicine procedures — because retained contrast can distort the DEXA reading. Many centres recommend waiting about a week. Indian families often book several health checks in one trip to save travel, so confirm this with the radiology desk rather than assuming it does not matter. Always disclose a possible pregnancy: although the radiation is low, DEXA is generally avoided in pregnancy.

Clothing matters too. Wear loose clothes without metal zips, hooks, belt buckles, or heavy embroidery over the waist and hip. If you arrive in a saree with pins, shapewear with metal clips, or jeans with thick buttons, the centre may ask you to change into a gown. You do not need to fast — you can eat normally, drink water, and take your usual medicines unless your doctor said otherwise. Diabetics do not need to skip meals for this test.

Total visit time is usually 15–20 minutes. Carry prior DEXA reports, a list of current medicines, and your fracture and menopause history, because comparison over time is part of proper interpretation. Mention any spine surgery, hip replacement, severe scoliosis, or metal implants, because the centre may need to scan the opposite hip or a different site.

If you are a daughter arranging the test for an older parent, the most useful preparation is often logistical: make sure she can lie flat for a few minutes, carry old reports, and note her fracture history. Try to recall whether a past fracture came from a true low-trauma event — a slip on wet bathroom tiles versus a high-impact fall — because that detail can change how the report is interpreted.

What Happens During the Procedure

A DEXA scan is one of the least intimidating imaging tests in medicine. You lie flat on your back on a padded table. The technologist positions you first for the lumbar spine, then for the hip. During the spine portion, your lower legs may rest on a padded box so the hips and knees bend — this flattens the lumbar spine into a standard position for more accurate measurement. Your body stays outside any tunnel, so this is nothing like an MRI and rarely causes any enclosed-space discomfort.

The scanning arm passes slowly over your body without touching you. There are no needles, no contrast dye, and no painful pressure. The main instruction is to lie still and breathe normally. For the hip images, your foot may be gently strapped or turned inward so the femur sits in a standard alignment. The positioning can feel slightly awkward for a few seconds, especially with arthritis or limited hip movement, but it is not usually painful. If you have back pain or cannot lie completely flat, tell the staff so they can adjust.

The scan usually covers the lumbar spine and hip. If the spine is not interpretable — because of severe Osteoarthritis in Postmenopausal Indian Women: Knees, Hips, Care, spinal hardware, or old fractures that can falsely raise the density reading — the report may rely more on the hip. Some centres also scan the forearm, particularly when both hips cannot be used or hyperparathyroidism is suspected.

There is no recovery period. You can get up, eat, travel, and resume work immediately. The report may be ready the same day in a private chain, or later in a teaching hospital. What matters after the scan is not the machine but the interpretation — a woman can finish a smooth scan and still leave confused if nobody explains whether a T-score of −1.8 means danger, whether medicine is needed, or how often to repeat the test.

So do not judge quality by how quickly the appointment was over. A fast scan is normal; a careless interpretation is not. A modest centre with good technique and a careful report is more useful than an expensive setting that hands over numbers without context — especially for older women who may have only a few scans in their lifetime and need each one to be clinically dependable.

How to Read the T-Score

The T-score is the headline number most people notice first. It compares your bone density with the average peak bone density of a healthy young adult, showing how far your bone mass has dropped from its strongest level. The standard interpretation is:

  • −1.0 or higher: normal
  • Between −1.0 and −2.5: osteopenia (low bone mass, not yet osteoporosis)
  • −2.5 or lower: osteoporosis
  • −2.5 or lower with a fragility fracture: severe or established osteoporosis

Osteopenia does not automatically mean harmless — it is a middle zone. A woman with a T-score of −1.3 and no other risk factors may only need lifestyle support and follow-up. Another woman with a T-score of −2.1, a prior wrist fracture from a minor fall, low body weight, and steroid exposure may be at genuinely high fracture risk and need medication. That is why the number must be read alongside fracture history and tools such as FRAX. A T-score is not a moral report card about whether you drank enough milk in your twenties; it is a risk marker that guides what to do next.

The site matters too. Doctors usually look at the lowest valid score among the lumbar spine, femoral neck, and total hip — but not blindly. Degenerative change in the spine, common in older women with osteoarthritis, can artificially make spinal density look better than it truly is, so hip scores may be more reliable in those cases. If you have had vertebral fractures, significant height loss, or persistent mid-back pain, the spine findings deserve extra attention even when the hip looks better.

Once a score drops into the osteoporosis range, the conversation shifts from general bone health to fracture-prevention strategy: calcium intake, vitamin D correction, weight-bearing and strength training, fall prevention, and medicines such as bisphosphonates or denosumab. Remember too that a T-score is not a guaranteed outcome — some women with osteopenia fracture because of falls and frailty, while many with osteoporosis stay fracture-free for years because they remain strong, active, and treated. The number matters most when it is translated into a plan.

What the Z-Score Tells Your Doctor

The Z-score is often ignored by patients, but it can be the most useful clue in younger women and anyone whose bone loss looks out of proportion. Instead of comparing you with peak young-adult bone mass, it compares you with people your own age and sex. So it answers a different question: not "How far am I from ideal peak bone mass?" but "How unusual is my bone density compared with my peers?"

A Z-score of −2.0 or lower is generally considered below the expected range for age. It does not by itself diagnose osteoporosis the way a T-score can in postmenopausal women, but it is a strong signal to look for causes beyond ordinary aging. In Indian practice, a low Z-score often triggers blood tests such as 25-hydroxy vitamin D, serum calcium and phosphorus, parathyroid hormone, alkaline phosphatase, thyroid-stimulating hormone, kidney function, and celiac screening. Depending on the history, doctors may add tests for cortisol excess, sex hormone deficiency, malabsorption, or — in the right age group — protein studies to screen for myeloma.

This matters especially in India, where high background rates of vitamin D deficiency often coexist with low calcium intake, indoor work, and delayed diagnosis of endocrine or gut disorders. A woman with diffuse body aches may be told for years that she is simply tired, when the real pattern is vitamin D deficiency, secondary hyperparathyroidism, and falling bone mass. Another may have untreated celiac disease, recurrent steroids for asthma, or an underactive thyroid. If the Z-score is very low, the scan becomes the beginning of the workup, not the end of it.

So no one should read a Z-score in isolation or panic over a negative number without context. A mildly reduced Z-score in an older woman may not change management if the T-score already explains the diagnosis. But a Z-score at or below −2 in a younger woman — especially before age 50 or before menopause — deserves a proper search for a secondary cause. Correcting vitamin D deficiency, parathyroid disease, thyroid excess, malabsorption, or inflammatory disease often improves long-term bone outcomes far more than simply adding calcium tablets.

In short, a low Z-score is a diagnostic doorway. The real value of DEXA here is not only finding low bone density — it is signalling when bone loss is too unusual to blame on age alone, sometimes uncovering a treatable problem years before repeated fractures occur.

How FRAX Adds Fracture-Risk Context

FRAX is a free online calculator, developed under the auspices of the World Health Organization, that estimates your 10-year probability of a major osteoporotic fracture and of a hip fracture. It combines clinical risk factors with (or without) femoral-neck bone density — in effect, translating a scan result into a future fracture probability. This matters most in the osteopenia range, where the T-score alone does not tell you whether medication is necessary.

The inputs typically include:

  • Age, sex, weight, and height
  • A prior fracture and parental hip fracture
  • Smoking and alcohol intake
  • Long-term glucocorticoid use
  • Rheumatoid arthritis and other causes of secondary osteoporosis
  • Femoral-neck BMD, if available

Two women can share a T-score of −1.9, but if one also has a previous fragility fracture, steroid exposure, rheumatoid arthritis, smoking, and lower body weight, her 10-year fracture risk is much higher. FRAX formalises that difference. In Indian practice it is especially helpful when a woman has osteopenia and the family is hesitant about long-term medication because the scan does not yet say "osteoporosis" — a calculated risk percentage makes the decision concrete.

FRAX has limits. It does not capture every variable and may understate risk in people with multiple recent falls, frequent steroid bursts, or significant spinal osteoporosis when the hip is not as low. It also depends on correct inputs and country settings. Still, as a decision aid it is valuable: a doctor may use it to explain why one woman with osteopenia only needs exercise, protein, calcium, and vitamin D correction, while another with a similar scan should start anti-resorptive treatment.

For patients, the practical takeaway is that the DEXA number and the FRAX estimate work together. If your score is in the osteopenia band, ask not only "What is my T-score?" but also "What is my 10-year fracture risk, and do my other risk factors change the plan?" FRAX is free; a fracture is not. Used alongside a careful history, it prevents both false reassurance and overreaction — and turns a grey-zone decision into a structured medical discussion rather than a family argument.

How Often the Scan Should Be Repeated

A DEXA is not a monthly monitoring test. Bone density changes slowly, and repeating the scan too often usually adds cost without useful information. As a rough guide:

  • Normal result, stable risk: roughly every 5 years
  • Osteopenia: every 2–5 years, depending on how close the score is to −2.5 and on other risk factors
  • On osteoporosis treatment: usually every 1–2 years, especially early in therapy

If the first scan is normal and you are clinically stable, repeating in about five years is reasonable. That interval shortens if your menopause status changes, steroids are started, a fragility fracture occurs, or new endocrine disease appears. For a healthy older woman with no major change in risk, annual repetition is usually unnecessary and not well supported by evidence — one of the most common private-sector problems is over-testing because a package includes yearly follow-up that the biology does not justify.

Women already on osteoporosis treatment are different. Repeating every one to two years helps assess whether bone density is stabilising or improving and whether adherence is adequate. If the scan worsens despite treatment, the doctor may look for missed secondary causes, review adherence, or change therapy. Once values are stable over time, the interval may be lengthened.

In India, repeat testing is also shaped by logistics — some women travel far to reach a DEXA machine, others change cities after retirement, and rural access remains limited. Comparison is most reliable when follow-up scans use the same machine and standardised technique, because tiny differences between reports may reflect technical variation rather than true biological decline. So follow-up should focus on meaningful trends, not decimal-point anxiety. If your plan is five-year follow-up, that is not neglect — it usually means the clinician understands that bone evolves slowly. The useful question is not whether you can repeat sooner, but whether anything about your fractures, medicines, menopause status, or health has changed enough to make an earlier repeat worthwhile.

When the Scan Leads to Treatment

Treatment is recommended when fracture risk is high enough that waiting is unsafe. The clearest triggers are:

  • A T-score of −2.5 or lower at a major site (femoral neck, total hip, or lumbar spine)
  • A fragility fracture of the hip or vertebra, regardless of the exact T-score
  • A high FRAX risk — commonly a 10-year hip fracture risk of 3% or more, or a major osteoporotic fracture risk of 20% or more

Treatment does not mean medicine alone. Foundational therapy includes adequate calcium (usually around 1,000–1,200 mg a day from diet and supplements combined), vitamin D (often 800–2,000 IU daily depending on deficiency status and medical advice), resistance and balance exercise, stopping smoking, limiting alcohol, and fall prevention. Many Indian women already take intermittent vitamin D sachets like Calcirol 60K and calcium tablets like Shelcal, but often irregularly or without confirming deficiency. Those products support treatment — they do not replace osteoporosis medication when fracture risk is high. For the sun-and-supplement realities behind this, see our guide to vitamin D and sun exposure for Indian women.

Drug options depend on age, fracture risk, kidney function, and preferences. Oral bisphosphonates such as alendronate are common first-line treatments because they are effective and relatively affordable. Intravenous bisphosphonates are used when tablets are not tolerated or adherence is poor. Denosumab is another effective option, often chosen when fracture risk is high or oral drugs are unsuitable, but it requires scheduled repeat dosing. Selective oestrogen receptor modulators may suit some postmenopausal women, and hormone therapy can help recently menopausal women who also have hot flushes or genitourinary symptoms, though those decisions are broader than bone density alone. In severe, very high-risk disease, anabolic therapy may be considered where available.

The Indian treatment conversation often centres on cost, fear of side effects, and family advice that reduces everything to "calcium deficiency." That is understandable but incomplete. Hip-fracture surgery, rehabilitation, prolonged bed rest, vertebral collapse, and dependence on caregivers are far more disruptive and expensive than timely prevention. The goal of treatment is not a perfect number but reducing fracture risk, stabilising bone loss, and preserving mobility — so medication can be worthwhile even when the next report is not dramatically better.

Costs and Access Across India

In private Indian healthcare, a DEXA scan commonly costs around Rs 1,500 to Rs 4,500, depending on city, centre, and whether the package covers only one site or both spine and hip with consultation. Large diagnostic chains advertise within this range, though pricing varies by city and franchise. Metro hospitals may charge more if the scan is bundled with a specialist visit; smaller stand-alone radiology centres may be cheaper, but quality and reporting standards matter. When comparing prices, ask which sites are included, whether the report gives both T-score and Z-score, and whether a clinician will explain the findings.

Public-sector access can be far cheaper — effectively free or highly subsidised at major teaching hospitals such as AIIMS, PGIMER Chandigarh, and JIPMER — though waiting time, registration, and travel can be higher. For many families, the hidden cost is not the scan but transport, lost wages, and an escort for an older relative, which is one reason testing gets postponed even when the headline price seems manageable. The free FRAX calculator can at least support a risk discussion while a scan is being arranged, but it is not a substitute for DEXA when a diagnosis is needed.

Urban access is much better than rural access. Many district towns still lack easy local availability, so women may need to travel to a city hospital or a screening camp. Rural older women are especially vulnerable — low dietary calcium, a lifetime of outdoor labour followed by reduced mobility, and little awareness that a silent fracture risk exists. Mobile DEXA services and bone-health camps are slowly emerging through hospital outreach and menopause-awareness programmes, but access remains uneven, and fractures still drive diagnosis in many non-metro settings.

Cost is best understood against downstream spending. Months of irregular self-medication with supplements may feel cheaper, but if a woman truly has osteoporosis, delayed diagnosis can lead to vertebral collapse, a hospital admission after a fall, hip-fracture surgery, prolonged pain, and caregiving dependence. Vitamin D sachets such as Calcirol 60K may cost roughly Rs 25–Rs 45 each, and common calcium brands like Shelcal may cost roughly Rs 120–Rs 300 a month — useful when indicated, but the scan is what decides whether that support is enough or whether formal treatment is needed. The most cost-effective scan is often the one that prevents a hospital admission two years later.

When to See a Doctor

Because osteoporosis is silent, the trigger to seek care is often a risk factor rather than a symptom. Talk to a doctor about a bone density scan if you:

  • Are a woman aged 65 or older, or are postmenopausal under 65 with any risk factor listed above
  • Have broken a bone from a minor fall or low-impact event (a "fragility fracture")
  • Have lost height (around 2–3 cm or more), developed a stooped upper back, or have new, persistent mid-back pain
  • Take long-term steroids, or have an inflammatory or autoimmune disease
  • Reached menopause early, had your ovaries removed, or have had prolonged absent periods

Some situations need prompt medical attention rather than routine screening. Seek care quickly if you have sudden, severe back pain after a minor strain or even no clear injury (a possible vertebral compression fracture), or if you cannot bear weight after a fall. A fall that results in a broken hip is a medical emergency.

Finally, if a scan or blood test in a younger woman points to a secondary cause — such as an overactive or underactive thyroid, parathyroid disease, celiac disease, or early ovarian failure — follow through on that workup. Treating the underlying problem often protects your bones more than supplements alone.

Common Myths, Corrected

Myth: DEXA is just another bone X-ray, so it does not add much

  • Fact: A plain X-ray is good for showing an existing fracture, but it is not sensitive for early bone loss. DEXA quantifies bone mineral density and provides T-scores and Z-scores that guide diagnosis and treatment.
  • Fact: DEXA focuses on high-risk sites such as the lumbar spine and hip — the exact areas where osteoporotic fractures cause major disability. That makes it clinically different from a routine skeletal X-ray ordered after pain or trauma.
  • Fact: Because the radiation dose is low and the scan is fast, DEXA is suited to preventive use. It can identify osteoporosis before the woman reaches the stage where an ordinary X-ray finally looks abnormal.

Myth: Only very thin women get osteoporosis

  • Fact: Lower body weight is a risk factor, but it is not the only one. Age, menopause, steroid use, prior fragility fracture, smoking, endocrine disease, vitamin D deficiency, and family history all matter.
  • Fact: Many Indian women of average body size still develop osteoporosis because of early menopause, low calcium intake, prolonged indoor work, repeated vitamin D deficiency, or chronic inflammatory disease. Saree or blouse size does not determine bone strength.
  • Fact: Women who appear healthy and active may still have silent vertebral bone loss. That is exactly why risk-based screening and DEXA are used instead of visual guesswork.

Myth: If I take calcium tablets, I do not need a DEXA scan

  • Fact: Calcium tablets such as Shelcal can support bone health, but they do not tell you whether you already have osteopenia or osteoporosis. Only a proper evaluation with DEXA can measure your current bone density.
  • Fact: Supplements alone are not adequate treatment for everyone. A woman with a T-score of −2.7 or a fragility fracture may need a bisphosphonate, denosumab, or another osteoporosis medicine in addition to calcium and vitamin D.
  • Fact: Taking supplements without assessment can delay diagnosis. In real practice, many women spend months on calcium and vitamin D while the actual fracture risk goes unmeasured and untreated.

Myth: Indian women do not really need DEXA unless they are very old

  • Fact: Indian women often carry multiple bone-health risks earlier than expected — premature menopause, low dietary calcium, high vitamin D deficiency rates, and delayed diagnosis of secondary causes. Waiting until a woman is very old misses preventable disease.
  • Fact: Indian Menopause Society and specialist practice patterns support routine screening at older ages and earlier testing in postmenopausal women with risk factors such as steroid use, fragility fracture, or premature menopause.
  • Fact: Indian bone-density observations have repeatedly shown that Indian women are not protected from osteoporosis by ethnicity. If anything, under-screening and under-treatment remain larger problems than over-testing.

Frequently asked questions

Is a DEXA scan painful or risky?

No. You simply lie flat on a padded table for about 15–20 minutes while a scanning arm passes over you. There are no needles or contrast dye, and the radiation dose is very low — far lower than a standard CT scan. It is generally avoided only in pregnancy.

What is the difference between a T-score and a Z-score?

The T-score compares your bone density with a healthy young adult at peak bone mass and is used to diagnose osteoporosis (−2.5 or lower) in postmenopausal women. The Z-score compares you with people of your own age and sex; a low Z-score (−2.0 or below) in a younger woman is a flag to look for a treatable secondary cause.

Do I need to fast or stop my medicines before a DEXA scan?

No fasting is needed — you can eat and drink normally and take most regular medicines. The main instruction is to avoid calcium supplements for about 24 hours before the test, and to postpone the scan if you have recently had a contrast study such as a barium meal.

How often should I repeat a DEXA scan?

It depends on your result and risk. A stable, normal scan is often repeated about every five years; osteopenia every two to five years; and women on osteoporosis treatment usually every one to two years. Annual scans for a low-risk person rarely add useful information.

How much does a DEXA scan cost in India?

In private centres it usually costs around Rs 1,500 to Rs 4,500, depending on the city, the centre, and whether both the spine and hip are scanned. Major government teaching hospitals such as AIIMS often provide it free or at a much lower cost, though waiting times can be longer.

I am in my forties with body aches — should I get a DEXA?

Body aches alone usually point more to vitamin D deficiency than to osteoporosis, and DEXA does not measure vitamin D. A DEXA is justified if you have specific risk factors such as steroid use, early or surgical menopause, an autoimmune disease, prolonged absent periods, or a prior low-trauma fracture. Discuss your individual risk with your doctor.

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