Positron emission tomography depends on a simple but elegant physical principle. A biologically active molecule, in this case fluorodeoxyglucose labelled with the positron-emitting isotope fluorine-18, is injected into the bloodstream. As the radiotracer decays, each positron annihilates with a nearby electron, producing a pair of gamma photons that fly off in nearly opposite directions. Ring-shaped detectors surrounding the patient register these coincident photon pairs, and reconstruction algorithms convert millions of such events into a three-dimensional map of where the glucose analogue has accumulated. Because cells with high metabolic demand, such as tumour cells or inflamed tissue, consume more glucose, FDG PET has become a cornerstone of oncology, cardiology and neurology.

Conventional PET scanners, however, cover only a modest axial length of the body, typically around 15 to 30 centimetres, which means that either the field of view must be moved along the patient or the region of interest must be chosen in advance. LAFOV systems change that equation dramatically. With detector rings extending across much of the body, and with markedly higher sensitivity thanks to a larger solid angle of coverage, these scanners can capture whole-body distributions in a single position, at lower injected activities, in shorter acquisition times, and, crucially, with the temporal resolution needed for true dynamic imaging. It is precisely this combination of sensitivity and continuous coverage that made the Copenhagen team’s fetal study feasible.

Dynamic PET is a fundamentally different exercise from the static snapshots that dominate routine practice. Rather than acquiring a single image after the tracer has distributed, dynamic protocols record the tracer’s journey continuously from injection onward: the bolus arriving through the maternal circulation, the transit across the placenta, and the gradual accumulation and clearance within fetal tissues. From these time-activity curves, quantitative parameters such as uptake rates and glucose metabolism can in principle be derived, rather than merely inferred from a single late time point. In the fetus, where every organ is growing and maturing at a different pace, such kinetic information has long been a tantalising but largely inaccessible prize.

The obstacles to fetal PET are formidable, which is why published examples remain rare. The fetus is a small, moving target suspended in amniotic fluid inside a body that is itself undergoing physiological change. Maternal organs, the placenta and the myometrium all lie in the imaging path, and the fetal signal must be separated from this crowded background. Fetal position shifts and maternal breathing add motion that standard reconstruction pipelines were never designed to handle. Radiation exposure, while modest with modern protocols, must be justified with particular rigour, and the physical dimensions of the pregnant abdomen challenge the geometric assumptions of scanner design. For all these reasons, fetal PET has historically been confined to isolated case reports, usually performed when a clinical question could not be answered by ultrasound or MRI.

That is precisely the context in which the Rigshospitalet report sits. As an Image of the Month contribution, the article documents a single, carefully justified clinical scenario in which the diagnostic value of dynamic FDG PET/CT outweighed the considerations that normally preclude it. The authors obtained written informed consent that explicitly covered the extended scan duration required for research purposes, as well as separate consent for the publication of data and images, underscoring the ethical scaffolding that surrounds any imaging of a pregnant patient. The study received no external funding, and the authors declared that the work itself was free of commercial involvement, although three of the authors noted honoraria from Siemens Healthineers for unrelated academic presentations and, in one case, an ongoing research agreement with the company.

The technical achievement deserves unpacking for readers unfamiliar with the machinery involved. A LAFOV PET/CT scanner pairs the extended PET field of view with computed tomography for anatomical localisation and attenuation correction. The CT component maps how strongly different tissues absorb photons, allowing the reconstruction algorithm to correct for the fact that gamma rays leaving the deep pelvis must traverse more tissue than those leaving superficial structures. In a pregnant patient this correction is especially delicate, because the attenuation landscape changes with fetal and placental position. The high sensitivity of the long-axis design means the injected activity can be kept as low as reasonably achievable, in line with the ALARA principle that governs all radiation medicine, while still collecting enough coincidence events to reconstruct images of diagnostic and scientific quality.

What can dynamic fetal FDG imaging actually reveal? Glucose is the fundamental fuel of the developing brain, and patterns of cerebral FDG uptake reflect the metabolic maturation of neural tissue. The placenta, an organ with its own distinctive glucose handling, appears in the images as a structure whose tracer kinetics can be followed over time. Fetal liver, heart and other organs each leave their metabolic signature. In principle, dynamic acquisition allows clinicians and researchers to distinguish between altered perfusion, altered transport and altered intracellular metabolism, distinctions that static imaging cannot make. For fetal medicine, where conditions such as growth restriction, congenital tumours and metabolic disorders are currently assessed largely through indirect ultrasound markers and MRI morphology, a direct quantitative window onto fetal metabolism represents a genuinely new class of information.

The publication also illustrates a broader shift in the culture of nuclear medicine. As total-body and long-axis PET installations proliferate in academic centres, investigators are revisiting patient populations and physiological questions that were previously off-limits, from ultra-low-dose paediatric studies to kinetic imaging of diffuse disease. The Danish team’s work is a case study in how new hardware creates new scientific opportunities almost as a side effect of its clinical deployment: a scanner bought for oncology becomes, with careful ethics approval and protocol design, an instrument for observing human development. The authors’ data availability statement, which offers access to the datasets on reasonable request, reflects the growing expectation that such rare and valuable imaging records should be shared with the wider research community.

Caution is, of course, the appropriate frame for a single-case Image of the Month. One examination cannot establish reference values, define normal fetal uptake patterns or change clinical guidelines, and the authors themselves present the work as a documentation of feasibility rather than a new standard of care. Yet the historical pattern in medical imaging is that today’s carefully documented case report becomes tomorrow’s protocol. Ultrasound, fetal MRI and even fetal echocardiography all began with isolated demonstrations that the previously invisible could be seen. If LAFOV dynamic PET follows the same trajectory, the Copenhagen images may be remembered as an early, technically demanding first look at the fetal body in motion, organ by organ, molecule by molecule, at the level of its glucose metabolism, a view that no previous generation of imaging technology could provide.

Subject of Research: Dynamic long-axial field-of-view PET/CT imaging of fetal fluorodeoxyglucose uptake

Article Title: Dynamic LAFOV PET/CT imaging of [18F]FDG uptake in the human fetus

Article References: Madsen, K., Korsholm, K., Andersen, F. L., & Andersen, T. L. (2026). Dynamic LAFOV PET/CT imaging of [18F]FDG uptake in the human fetus. European Journal of Nuclear Medicine and Molecular Imaging. https://doi.org/10.1007/s00259-026-08192-8

Image Credits: AI Generated

DOI: 10.1007/s00259-026-08192-8

Keywords: PET/CT, LAFOV PET, FDG, fetal imaging, dynamic PET, molecular imaging, nuclear medicine, fetal metabolism, radiotracer, placenta, prenatal diagnostics, Copenhagen University Hospital

The central premise of the field has not changed: imaging the dead can answer questions that matter enormously for the living. When a fetus dies in utero, when a newborn succumbs shortly after birth, or when a child dies unexpectedly, families and clinicians want answers. Conventional autopsy has long been the gold standard, but consent rates for full autopsy have fallen across much of the world, driven by religious and cultural concerns, emotional distress and simple unfamiliarity with the procedure. Less-invasive alternatives that use imaging — chiefly postmortem computed tomography and postmortem magnetic resonance imaging — promise a way to recover diagnostic information while respecting families’ wishes. That promise, the commentary argues, has come substantially closer to reality over the past ten years.

The turning point came in organizational form. In 2016, the European Society of Paediatric Radiology convened a dedicated postmortem imaging task force, building on an earlier questionnaire-based survey that had revealed how inconsistent practice was across European centres. That survey, published in 2014, documented wide variation in whether imaging was offered at all, which modalities were used, and how results were reported. The task force gave the field a focal point: a standing group of experts who could translate scattered research findings into practical, consensus-based guidance. The commentary’s authors, who have led much of this effort, frame the past decade as the story of what happened once that structure existed.

The most tangible products of that structure are the protocols. In 2019, a joint working group of the European Society of Paediatric Radiology and the International Society for Forensic Radiology and Imaging published the first standardized protocol for paediatric postmortem computed tomography, specifying how scans should be acquired in children of different sizes and ages. More recently, the task force has turned to magnetic resonance imaging, publishing a referral template for fetal and neonatal postmortem imaging in 2024, a full clinical protocol for fetal and neonatal postmortem MRI in 2025, and, in 2026, recommendations for standardized structured reporting of those examinations. Reporting guidance for perinatal and paediatric postmortem CT followed a parallel track, published in Insights into Imaging in 2024.

Standardized reporting deserves particular emphasis because it addresses one of the field’s most stubborn problems. An imaging study is only as useful as the report that follows it, and early adopters of postmortem MRI found that radiologists described findings in wildly different ways, making it difficult to compare results across centres or to accumulate the evidence base needed to convince coroners, pathologists and funders. The 2026 structured reporting recommendations aim to fix this by defining what must be documented, in what order and with what terminology, so that a postmortem MRI report from Amsterdam can be read and trusted in London, Toronto or Melbourne. It is the kind of unglamorous infrastructure work that rarely makes headlines but determines whether a technique becomes routine or remains a curiosity.

The evidence base itself has grown in parallel. One of the decade’s most influential studies, the DRIFT trial published in The Lancet Child & Adolescent Health in 2018, compared chest radiographs with computed tomography for detecting rib fractures in children and provided diagnostic accuracy data that directly inform how skeletal injury should be assessed after death. Other work has pushed into more sophisticated territory: diffusion-weighted postmortem MRI of the fetal brain has been used to help time perinatal deaths, a question with real forensic and medico-legal significance, while feasibility studies have explored multiparametric mapping and spectroscopy approaches that quantify the biochemical changes tissues undergo after death. These quantitative techniques remain largely research tools, but they hint at a future in which postmortem imaging does more than mirror autopsy — it measures things autopsy cannot.

Geography, however, remains a limiting factor. A 2023 survey of North American practice found that paediatric postmortem imaging is used far less consistently there than the European literature might suggest, and a companion European survey published the same year examined the fragile funding streams that support the work. Postmortem imaging often falls between budgetary stools: it is not routine diagnostic imaging with a living patient, nor is it always funded as part of forensic or medico-legal investigation. The commentary is candid that reimbursement and sustainable financing are now among the biggest obstacles to wider adoption, perhaps bigger than any technical question about image quality or diagnostic accuracy.

The institutional response has been to widen the coalition. In 2026, a multi-society statement on implementing paediatric and fetal postmortem imaging into clinical practice was issued jointly by the European Society of Paediatric Radiology, the Society for Pediatric Radiology, the Latin American Society of Pediatric Radiology, the Asian and Oceanic Society for Pediatric Radiology, the World Federation of Pediatric Imaging and the International Association of Forensic Radiographers. That breadth matters. It signals that the field is no longer a European project but a global one, and it gives radiologists, pathologists, coroners and health administrators on multiple continents a common reference point when they argue for local services.

Technology continues to move as well. Among the developments highlighted in the commentary’s own journal is early experience with photon-counting detector CT in paediatric postmortem imaging, a detector technology that offers higher spatial resolution and improved tissue contrast at comparable or lower radiation exposure than conventional CT. For a field whose credibility depends on detecting small, subtle findings — a hairline rib fracture, a tiny intracranial haemorrhage, a subtle malformation — such hardware advances could meaningfully shift diagnostic performance. The commentary also notes the publication of a comprehensive textbook on postmortem imaging of the fetus and child in 2025, consolidating a decade of accumulated knowledge into a single reference for practitioners entering the field.

Where does the field go from here? The commentary’s implicit answer is that the scientific groundwork has largely been laid and the remaining battles are organizational: funding, service implementation, training and the slow work of convincing legal systems and bereaved families that imaging can stand alongside — or in some cases replace — conventional autopsy. For early pregnancy loss, less-invasive autopsy approaches have already been shown to offer families answers where a full autopsy would be declined. The decade since “mortui vivos docent” has not eliminated the need for pathologists, and few in the field claim it should; instead, imaging has become a complementary tool that can guide autopsy, replace it when families refuse it, and extract information from bodies that must otherwise go unexamined. The dead, it turns out, teach the living best when the living build the systems to listen.

Subject of Research: Paediatric and perinatal postmortem imaging

Article Title: 10 years of paediatric and perinatal postmortem imaging: where are we now?

Article References: Arthurs, O. J., & van Rijn, R. R. (2026). 10 years of paediatric and perinatal postmortem imaging: where are we now?. Pediatric Radiology. https://doi.org/10.1007/s00247-026-06795-9

Image Credits: AI Generated

DOI: 10.1007/s00247-026-06795-9

Keywords: postmortem imaging, paediatric radiology, perinatal autopsy, postmortem MRI, postmortem CT, ESPR task force, less-invasive autopsy, fetal imaging, forensic radiology, structured reporting, photon-counting CT, Pediatric Radiology