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When the Final Test Turns Silent: A Story of PET-CT and the Mystery of False Negatives

  In radiology, we often say that a PET-CT is a “last resort” test—when every other scan has raised suspicion, when symptoms persist, when blood markers whisper trouble. Patients enter the scanner expecting answers. Doctors order it hoping for clarity. Families wait outside believing that  this  is the test that will finally reveal the truth. But sometimes, the most advanced test stays silent. And silence can be confusing. This is a story about that silence. The Patient Who Carried a Question She was 54, an office worker who had spent the last six months visiting hospitals more than her workplace. Fatigue that didn’t go away. A cough that felt out of place. A patch on her CT that was “not alarming but not reassuring either.” Her physician said the most honest words a doctor can say— “I’m not satisfied with this picture.” So, after rounds of blood work, X-rays, a contrast CT, and even a bronchoscopy, she was sent for a PET-CT. “This is the final test,” she told me as she l...
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Interval Breast Cancer: What a 6.5-Million–Mammogram Study Teaches Us About Missed Opportunities in Screening

  Interval Breast Cancer (IBC) remains one of the most important quality markers in breast cancer screening programs. These are cancers diagnosed  after a negative screening mammogram but before the next scheduled screen —and they represent the uncomfortable gray zone between biology, technology, and human interpretation. A recent large-scale study from Taiwan, analyzing  6.5 million screening mammograms  in  2.88 million women , provides one of the most comprehensive insights into  why interval cancers happen and how we can reduce them . 1. Dense Breasts: Still the Biggest Blind Spot The study confirms the firm association between breast density and the risk of IBC: Extremely dense breasts (BI-RADS D): IBC risk = 1.15 per 1000 person-years Fatty breasts (BI-RADS A): IBC risk = 0.29 per 1000 person-years That’s nearly a  4X increase . Dense breast tissue not only hides cancers but is also biologically more prone to aggressive tumors. For clinicians, th...
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Why Quadrature RF Coils Are Preferred?

  1. Higher Signal-to-Noise Ratio (~40% improvement) A  quadrature coil  uses  two coils placed 90° apart , receiving signals in two orthogonal directions. These two independent signals combine  constructively , giving: √2 (≈ 1.41×) higher SNR Better image quality, especially for low-signal tissues. More SNR = better resolution, faster scans, or both. 2. Better Sensitivity to Circularly Polarized MR Signal The MR signal emitted by precessing protons is  circularly polarized . A single coil picks up only  one component  of this circular motion. A quadrature coil picks up  both components , matching the physics of precession much better → more efficient signal capture. 3. Reduced Noise Noise is random and uncorrelated between the two coils, while MR signal is correlated. When signals combine: Signal adds  coherently Noise adds  incoherently ➡️ Improves SNR without increasing noise. 4. Less Transmit Power Needed In transmit mode, quadr...
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PD-MRA vs HR-MRA: A Game-Changer for Indeterminate Intracranial Aneurysms?

  Indeterminate intracranial aneurysms  are one of the most frustrating gray zones we face in neurovascular imaging. A small bulge at the PCom origin, a questionable ACom prominence, or an ICA outpouching that “could be” an infundibulum—these findings often push clinicians toward invasive angiography purely to clarify anatomy. A recent study comparing  Proton-Density MRA (PD-MRA)  with high-resolution  Time-of-Flight MRA (HR-MRA) brings a major shift: ➡️  PD-MRA dramatically outperforms HR-MRA  in diagnosing aneurysms among indeterminate lesions. ➡️ Offers  near-perfect interobserver agreement . ➡️ May  reduce the need for DSA  in many borderline cases. This blog breaks down the study highlights into simple, clinically useful points. Why This Study Matters In day-to-day reporting: 3–5 mm (or smaller) vascular bulges are  frequently indeterminate  on CTA/MRA. Up to  18% of lesions  on standard MRA fall into this ambigu...
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Osseous Metaplasia of the Endometrium: A Rare but Striking Ultrasound Finding

  Osseous metaplasia of the endometrium is an  uncommon yet unforgettable  diagnosis on pelvic ultrasound. Although rare, recognizing it is important because it is a  treatable cause of secondary infertility  and is frequently misinterpreted as retained products of conception (RPOC) or chronic endometritis. What Is Endometrial Osseous Metaplasia? A condition where  bone tissue forms within the endometrium , usually after a prior pregnancy loss. The proposed mechanisms include: Metaplastic transformation of endometrial stromal cells Chronic inflammation stimulating osteoblastic activity Retained fetal bone fragments (less common) Typical Ultrasound Appearance Ultrasound is often diagnostic due to its characteristic features: On grayscale USG: Highly  echogenic linear or plate-like foci  within the endometrial cavity Posterior acoustic shadowing  — often dense Fragmented, irregular calcific elements Endometrial thickening may be present On Dopp...
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Enhanced Myometrial Vascularity (EMV): The Most Misunderstood Doppler Finding After Pregnancy Loss

  Enhanced Myometrial Vascularity (EMV)  is one of the most striking and often misunderstood sonographic findings encountered after miscarriage, medical termination, or delivery. For years, many clinicians labelled it as  uterine arteriovenous malformation (AVM)  — a diagnosis that carries heavy implications and often leads to unnecessary interventions such as uterine artery embolization. A recent expert review by Dewilde et al. (2023) clarifies the confusion and emphasizes that  EMV is not an AVM  — and recognizing this distinction is crucial for safe, evidence-based management. What Exactly Is EMV? EMV refers to  dilated, tortuous, high-velocity, low-resistance myometrial vessels  seen on Doppler imaging beneath  retained pregnancy tissue . It is  a physiological, temporary, pregnancy-related vascular change , not a congenital malformation. It arises because the  placental bed vessels remain open and high-flow  as long as any...
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When the Thymus Tells a Story: Evaluating Thymic Abnormalities in a Child With Suspected Myasthenia

 Hello Glias ! Today’s pediatric case was a 7-year-old with  signs suggestive of myasthenia gravis  — fatigability and ptosis — but  negative for anti–acetylcholine receptor antibodies . Given the presentation, our task was to  rule out thymic pathology , particularly  thymoma or thymic hyperplasia , on imaging. Why the Thymus Matters in Pediatrics The thymus, though often forgotten after infancy, plays a central role in  T-cell maturation  and immune regulation. It  enlarges rapidly in infancy , peaks at  puberty , and then  involutes gradually , replaced by fat with age. However, in children,  normal thymus can appear large  — and this can easily raise unnecessary alarms unless interpreted in the right context. 📚  According to Manchanda et al. (WJCP, 2017) : “The thymus attains maximum weight at puberty and gradually becomes replaced by fat and involutes with age. However, it can grow back (rebound) after stress or...
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