The review, led by Muhammad Danyal Ahsan and colleagues at Weill Cornell Medicine, was preregistered with PROSPERO and conducted according to the PRISMA 2020 reporting standard. The team searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from their inception through August 2025, screening 18,231 abstracts to identify 17 original research studies published between 2005 and 2024. The studies came from eight countries, with Germany contributing nine of the seventeen, and sample sizes ranged from 22 to 7,287 participants. Critically, the researchers only included studies of people who had no established indication for the scan, excluding patients with known hereditary cancer syndromes, people undergoing cancer staging or recurrence surveillance, and studies that selectively reported results from a single organ system.

The headline numbers are striking. Across the pooled data, only 16.9 percent of scanned individuals had no findings reported, while 78.0 percent had at least one finding. That sounds alarming until the nature of those findings is examined. The most common abnormalities were degenerative spinal disease in 22.0 percent of scans, subcortical cysts in 15.4 percent, and bone marrow edema in 6.2 percent, conditions that are ubiquitous in aging populations and rarely change clinical management when discovered incidentally. The authors estimate that roughly 62 to 67 percent of people undergoing whole-body MRI without a medical indication will receive findings that are not actionable at all.

A smaller but clinically meaningful fraction of scans did flag something requiring attention. Non-malignant actionable findings, defined as non-cancerous abnormalities that prompted laboratory testing, additional imaging, or procedural follow-up, were reported in 14.8 percent of screened individuals. These were most frequently located in the gastrointestinal system, the musculoskeletal system, and the lymphatic or vascular system. The most common specific actionable findings were hepatic steatosis, or fatty liver, in 8.8 percent, pulmonary nodules in 4.8 percent, and uterine fibroids in 4.3 percent. Among the people with such findings, 58.2 percent went on to pursue additional laboratory work or imaging, and 20.8 percent underwent a subsequent procedure such as endoscopy, biopsy, resection, or surgery.

Herein lies the central problem the review exposes: none of the included studies reported the results of that downstream evaluation. Because diagnostic resolution was never documented, the authors could not calculate false-positive rates, overdiagnosis rates, or any measure of whether the follow-up testing ultimately helped or harmed patients. This is a fundamental gap for a screening technology. Screening is only justified when it demonstrably improves clinical outcomes, and the history of medicine is littered with tests that found plenty of abnormalities without extending a single life. Prostate-specific antigen screening and routine diabetes screening in asymptomatic adults, for example, have not proven effective at reducing all-cause mortality, despite detecting real biochemical and metabolic signals.

The cancer detection numbers offer a more nuanced picture. Among the 4,463 participants in the eleven studies that reported pathologically confirmed oncologic outcomes, malignancy was detected in 1.4 percent, with a 95 percent confidence interval of 0.9 to 2.2 percent. The most common cancers found were genitourinary tumors, accounting for 21.8 percent of detections, followed by cancers of the female reproductive system at 19.5 percent and gastrointestinal cancers at 16.5 percent. Notably, the authors point out that roughly 60 percent of the malignancies discovered were in organ systems for which the US Preventive Services Task Force offers no Grade A or B screening recommendation, since current guidelines cover only breast, cervical, colon, and lung cancers. Fewer than 20 percent of US cancers are diagnosed through existing screening programs, which is precisely the gap that multi-organ scanning hopes to fill.

For context, the pooled malignancy yield of whole-body MRI sits within or above the per-examination detection rates of some recommended screening tests. Mammography detects roughly 0.2 to 0.8 percent of cancers per screening round, and colonoscopy detects approximately 0.14 to 0.20 percent. But the authors are careful to emphasize that diagnostic yield alone establishes nothing about clinical benefit. A scan that finds more cancers is not automatically a scan that saves lives; the detected cancers must be ones that would have become lethal without early detection, and the harms of chasing false positives and indolent lesions must be weighed against any mortality reduction. Those calculations simply cannot be made with the current evidence.

The methodological quality of the underlying literature is another major caveat. None of the seventeen included studies was free from risk of bias across all domains when assessed with Joanna Briggs Institute tools, and limitations included concerns about sampling, sample size, and confounding. Statistical heterogeneity between studies was extreme, with I-squared values exceeding 90 percent across most analyses, reflecting differences in the use of contrast agents, diffusion-weighted imaging, vascular protocols, body coverage, thresholds for calling a finding actionable, and outcome definitions. The confidence intervals around the pooled estimates are correspondingly wide; the 95 percent interval for the proportion of scans with any finding spans from 44.9 to 93.9 percent. A funnel plot for the malignancy analyses also showed asymmetry consistent with publication bias or selective reporting, meaning studies that found more cancers may have been more likely to be published.

Generalizability is a further concern. All of the included studies came from non-US healthcare systems in East Asia, Western Europe, and the Middle East, and several involved employer-sponsored, private, or otherwise selected cohorts rather than representative community samples. The pooled cohort was 64.9 percent male, no studies reported race and ethnicity data, and only seven of the seventeen studies explicitly described their populations as asymptomatic. Meanwhile, the commercial landscape that the review is meant to inform is dominated by direct-to-consumer services such as Prenuvo and Function Health, which charge approximately 500 to 3,000 dollars per scan with variable protocols and are often bundled with additional clinical assessments. Marketing campaigns and celebrity endorsements have amplified public interest, yet no professional society, including the American College of Radiology, the USPSTF, or the National Comprehensive Cancer Network, endorses whole-body MRI for the general population.

The authors argue that the technology itself is not the problem; the evidence base is. Whole-body MRI is radiation-free, images multiple organ systems in a single session, and could theoretically address real barriers to preventive care, since organ-specific screening requires multiple visits, is sometimes invasive, and suffers from suboptimal adherence. Advances in artificial intelligence may further reduce acquisition time and standardize interpretation, and the authors suggest that a consensus reporting taxonomy extending the oncologic ONCO-RADS system to cardiovascular, musculoskeletal, and metabolic abnormalities could reduce variability and unnecessary follow-up. But until high-quality observational studies or randomized controlled trials track patients from initial finding through downstream workup to hard outcomes such as morbidity, mortality, overdiagnosis, and cost, the review concludes that most whole-body MRI examinations in people without a medical indication reveal either nothing or nothing that matters, and the clinical value of the scan remains an open question rather than a settled fact.

Subject of Research: Diagnostic yield of whole-body MRI as a multi-disease screening tool in people without an evidence-based indication

Article Title: The Diagnostic Yield of Whole-Body MRI as a Multi-disease Screening Modality: A Systematic Review and Meta-analysis

Article References: Ahsan, M. D., Frontera, N., Gurram, A., Sharaf, S., Qazi, M., Patel, D., Yang, K., Gioia, S., Murray, I. R., McGonigle, R., Guniganti, P., Dodelzon, K., Ma, X., Kierans, A. S., Diamond, L. C., Godwin, K., Shih, G., Sabuncu, M., Lantos, J., … Sharaf, R. N. (2026). The Diagnostic Yield of Whole-Body MRI as a Multi-disease Screening Modality: A Systematic Review and Meta-analysis. Journal of General Internal Medicine. https://doi.org/10.1007/s11606-026-10802-y

Image Credits: AI Generated

DOI: 10.1007/s11606-026-10802-y

Keywords: whole-body MRI, screening, diagnostic yield, meta-analysis, overdiagnosis, cancer detection, incidental findings, preventive medicine, medical imaging, false positives, systematic review, direct-to-consumer health

The study, published in BMC Medical Imaging, was led by Seckin Bilgic and colleagues at the Department of Nuclear Medicine of Bursa Uludag University, with additional contributions from Canakkale Onsekiz Mart University and Bursa Yuksek Ihtisas Training and Research Hospital. The team set out to answer a deceptively simple question: when adults undergo fluorine-18 fluorodeoxyglucose positron emission tomography and computed tomography, known as 18F-FDG PET/CT, for cancer evaluation, how often do their kidneys show abnormalities, and how often do those abnormalities actually make it into the written report? The answer, according to their data, is that kidney findings are remarkably common and remarkably under-reported.

The researchers examined 283 consecutive adult patients who underwent oncologic 18F-FDG PET/CT at their institution between March and April 2023. Consecutive enrollment matters here, because it means the cohort was not cherry-picked; these were simply the patients who came through the door during a defined two-month window. The study received ethical approval from the Bursa Uludag University Ethics Research Committee and was conducted in accordance with the 1964 Helsinki Declaration, with informed consent obtained from all subjects. Because the design was retrospective and observational, the investigators could go back and scrutinize the images with a level of systematic attention that busy clinical workflows do not always permit.

What did that scrutiny reveal? The numbers are eye-opening. At least one cortical or pelvicalyceal renal abnormality was identified in 192 of the 283 patients, which works out to 67.8 percent of the cohort, with a 95 percent confidence interval spanning 62.2 to 73.0 percent. In other words, roughly two out of every three cancer patients scanned carried some detectable kidney abnormality on their PET/CT images. The abnormalities fell into two broad morphological categories. Cortical abnormalities, which affect the outer functional tissue of the kidney, were present in 123 patients, or 43.5 percent, and were most commonly large cortical cysts, seen in 22.3 percent of the full cohort. Pelvicalyceal abnormalities, which involve the urine-collecting system deep within the kidney, appeared in 129 patients, or 45.6 percent.

The technical distinction between these two categories is worth unpacking, because it reflects the dual nature of the information contained in a PET/CT scan. The CT component provides high-resolution anatomical detail without contrast enhancement in this setting, allowing reviewers to assess the renal cortex for cysts, masses, and structural changes. The pelvicalyceal system, meanwhile, can be evaluated for dilatation, stones, and other collecting-system pathology. The researchers even developed a stepwise visual grading algorithm, described in their supplementary material, to classify pelvicalyceal dilatation from Grade 0 to Grade 3 based on renal pelvic fullness, calyceal dilatation, and associated thinning of the renal parenchyma. Notably, they used the fused PET/CT images only for anatomical correlation and deliberately ensured that the intense urinary excretion of FDG, which naturally accumulates in the collecting system, did not influence grade assignment. That methodological care matters, because urinary FDG activity is a well-known confounder that can obscure or mimic collecting-system findings.

But prevalence alone was not the heart of the study. The investigators also wanted to know whether the kidney findings they identified on systematic review had ever been documented before. For the 192 patients with at least one renal abnormality, they reviewed available pre-index institutional records, meaning prior imaging and reports already on file at the institution, and classified each patient’s findings as previously documented, mixed, or incidentally identified. The result was stark: only 20 patients, or 10.4 percent, had findings that were entirely previously documented. Another 31 patients, or 16.1 percent, had a mixed picture, with some findings known and some new. The remaining 141 patients, a full 73.4 percent, had kidney abnormalities that were entirely new discoveries, never before captured in the institutional record. Taken together, 172 of the 192 affected patients, or 89.6 percent, had at least one renal abnormality that had never been documented anywhere in their available records.

The most sobering comparison, however, came when the researchers turned to the original clinical PET/CT reports, the documents written by the interpreting physicians at the time of the scan and sent to the treating oncologists. Of the 192 patients whose scans showed renal abnormalities on standardized retrospective review, only 58, or 30.2 percent, had at least one of those abnormalities mentioned in the original report. The other 134 patients, 69.8 percent of those with findings, had no renal abnormality documented at all. The gap between what a systematic review could see and what the clinical report conveyed is the central finding of the paper, and it is difficult to read those numbers without wondering how many clinically meaningful findings slip through the cracks in routine practice.

Why does this happen? The authors point to the inherent structure of oncologic imaging interpretation. A PET/CT study ordered for cancer staging or surveillance generates hundreds of images, and the interpreting physician’s primary obligation is to the clinical question at hand: tumor location, metabolic activity, treatment response, and new metastatic disease. Kidney cysts and mild collecting-system dilatation are, in the vast majority of cases, benign and clinically silent, and flagging every one of them in every report would risk burying the critical oncologic information in a flood of incidental detail. This is the classic tension of incidental findings in modern imaging: as scanners have grown more sensitive and datasets more voluminous, the sheer volume of non-target abnormalities has outpaced any practical reporting strategy. Yet the study’s data suggest the pendulum may have swung too far, with nearly 90 percent of affected patients carrying at least one renal finding absent from all available documentation.

The clinical stakes are not trivial. Some incidental renal abnormalities, particularly complex cysts and solid-appearing cortical lesions, can represent early renal cell carcinoma, a malignancy that is highly curable when caught at a small size but far more dangerous when it grows undetected. Hydronephrosis and collecting-system dilatation can signal obstructing stones or tumors that merit follow-up. Chronic kidney disease, too, often announces itself first through subtle structural changes visible on cross-sectional imaging. Whether the abnormalities catalogued in this study would have changed outcomes for any individual patient is a question the retrospective design cannot answer, and the authors are appropriately measured on this point. They explicitly state that further studies should determine whether more systematic recognition and reporting of these findings influences diagnostic evaluation, clinical decision-making, and patient management.

Still, the study lands at a moment when the imaging community is actively grappling with how to handle the incidentalome, the ever-growing list of unexpected findings generated by modern scans. Structured reporting templates, standardized checklists for organ systems outside the region of interest, and artificial intelligence tools that pre-screen images for non-target abnormalities are all under active investigation as potential solutions. This study provides a concrete baseline for one organ system in one high-volume imaging context, and its message is clear: kidney abnormalities are present in more than two-thirds of oncologic PET/CT patients, yet nearly 70 percent of affected patients leave the encounter with none of those findings on paper. Closing that gap, without drowning the oncologic signal in incidental noise, may be one of the defining reporting challenges of the PET/CT era. The authors received no specific funding for the work and declared no competing interests, and the article is published open access under a Creative Commons license, making the full data and methods available to any research group hoping to replicate or extend the findings.

Subject of Research: Prevalence and under-reporting of incidental renal abnormalities detected on oncologic 18F-FDG PET/CT imaging

Article Title: Incidental renal abnormalities on 18F-FDG PET/CT in oncologic patients: prevalence and reporting practices

Article References: Bilgic, S., Koroglu, I., Akovalı, B., Sahin, H. G., & Alper, E. (2026). Incidental renal abnormalities on 18F-FDG PET/CT in oncologic patients: prevalence and reporting practices. BMC Medical Imaging. https://doi.org/10.1186/s12880-026-02859-2

Image Credits: AI Generated

DOI: 10.1186/s12880-026-02859-2

Keywords: 18F-FDG PET/CT, incidental findings, renal abnormalities, oncologic imaging, kidney cysts, pelvicalyceal dilatation, reporting practices, nuclear medicine, radiology, renal cell carcinoma, patient safety, medical imaging

The research team, led by Le Song and Na Guo, with Weifang Zhang as corresponding author, combed through bone scintigraphy studies performed at their institution between 2019 and 2022. Among thousands of scans, they identified 66 patients who displayed focal uptake within the orbital region, an incidence of roughly 0.9 percent of all bone scans. That figure alone is informative: orbital uptake is uncommon, which is precisely why most physicians have lacked the large, longitudinally followed cohorts needed to say anything confident about it. By assembling 66 patients and evaluating 76 distinct orbital foci, the Beijing group created one of the first multi-modality portraits of this finding, combining planar bone scintigraphy with magnetic resonance imaging, computed tomography, fluorine-18 fluorodeoxyglucose positron emission tomography, and, crucially, follow-up imaging over many months.

The anatomical and morphological patterns that emerged were strikingly consistent. Of the 76 orbital foci, 61, or 80.3 percent, localized to the superior or lateral walls of the orbit, and 72, or 94.7 percent, appeared round in shape. Those two features, a predilection for the upper and outer orbital walls and a rounded contour, are exactly what one would expect from slow-growing, indolent processes such as fibrous dysplasia or other benign osseous variants, and exactly what one would not expect from the ragged, permeative architecture of metastatic deposits. Meanwhile, the extra-orbital findings in these patients told a separate story about why the scans had been ordered in the first place: five patients had bona fide skeletal metastases elsewhere, 34 showed degenerative changes, and 17 harbored other benign lesions.

The technical heart of the study lies in its quantitative analysis of the target-to-nontarget ratio, a standard measure in bone scintigraphy that compares tracer intensity in a suspicious focus with that in adjacent normal bone. In the 27 patients who underwent follow-up bone scintigraphy, at a median interval of 23.0 months, the median T/NT ratio drifted from 4.9 down to 3.7, a change that did not reach statistical significance, with a P value of 0.301. More telling than the ratio itself was the visual verdict: 25 of 28 lesions examined longitudinally appeared unchanged on side-by-side comparison, and that stability held equally among patients with known metastatic disease, four of five lesions, and patients without metastases, 21 of 23 lesions. Metastatic lesions in bone, by contrast, typically evolve, intensifying as disease progresses or fading in response to therapy, particularly during the flare phenomenon that follows effective treatment.

Magnetic resonance imaging provided a second, complementary line of evidence. Within 14 days of their bone scans, 31 patients underwent orbital MRI, which detected abnormal orbital lesions in 16 patients, corresponding to 16 lesions with a mean size of 9.0 plus or minus 2.4 millimeters. The frontal bone was involved in ten cases and the zygomatic bone in six, once again mirroring the superior and lateral orbital walls highlighted on scintigraphy. When the researchers applied the Bone Reporting and Data System, a structured classification scheme designed to standardize the risk assessment of bone lesions, 12 of these lesions fell into the low-concern category 2 or 3, while four were assigned to the more worrisome category 4. Follow-up MRI in 11 lesions showed no change in size over time, although two lesions did display evolution in their signal characteristics, a reminder that even ostensibly benign orbital lesions deserve at least individualized attention rather than reflexive dismissal.

It was computed tomography, however, that emerged as the decisive diagnostic tool. In 21 patients who underwent CT or fluorine-18 FDG PET/CT at a median interval of eight months from the index bone scan, CT identified abnormal orbital findings in 20 patients, totaling 21 foci. Nineteen of those 21 foci, all but one, displayed unambiguously benign features. Eighteen were classified as Bone-RADS category 1, and 16 of these showed the classic ground-glass opacity, a hazy, milky pattern of mineralization that radiologists regard as a near-signature of fibrous dysplasia, a developmental benign bone lesion in which normal marrow is replaced by a fibrous tissue woven with immature trabeculae. Two further foci were lucent lesions of Bone-RADS category 2 or 3. The single exception was an osteolytic lesion of the sphenoid bone exhibiting cortical destruction, assigned Bone-RADS category 4, with an SUVmax of 5.1 on PET, findings that were interpreted as suggestive of metastasis. That outlier is clinically important: it demonstrates that while the pattern is overwhelmingly benign, the occasional genuine metastasis does hide among these hot spots, and imaging characterization, not assumption, is what separates the two.

The metabolic dimension of the study adds a third layer of reassurance. On fluorine-18 FDG PET/CT, the 20 benign-appearing foci showed minimal fluorodeoxyglucose uptake, with a median maximum standardized uptake value of just 1.4. FDG avidity reflects glucose metabolism, and actively proliferating tumor tissue typically consumes the tracer eagerly, driving SUV values well above the benign threshold. A median SUVmax of 1.4 places these orbital lesions firmly in the metabolically quiet company of normal tissue, consistent with the slow, remodeled bone of fibrous dysplasia rather than the voracious biochemistry of metastatic carcinoma. Taken together, the low metabolic activity, the rounded morphology, the characteristic ground-glass attenuation on CT, and the longitudinal stability across a median follow-up approaching two years form a converging constellation of benignity that is difficult to argue with.

Why does this matter beyond the reading room? Incidental findings have become one of the defining challenges of modern imaging. As scanners grow more sensitive and whole-body protocols more common, radiologists increasingly detect anomalies whose clinical significance is unknown, and each of them triggers a cascade of anxiety, additional testing, cost, and sometimes unnecessary invasive procedures for patients already frightened by cancer diagnoses. Bone scintigraphy is performed millions of times a year worldwide, and if roughly one percent of those scans carry an orbital hot spot, the aggregate burden of uncertainty is substantial. By demonstrating that these foci have a reproducible benign signature, the study converts a source of ambiguity into a pattern that can be recognized, characterized, and, in most cases, safely managed without biopsy or aggressive intervention.

The study also carries a practical methodological lesson about the relative strengths of different imaging modalities. MRI, so exquisitely sensitive to marrow infiltration and soft tissue, proved less definitive for these osseous lesions, and its signal characteristics could even evolve over time in ways that complicate interpretation. CT, by contrast, excelled at characterizing the internal architecture of the bone itself, reliably distinguishing the ground-glass mineralization of fibrous dysplasia from the cortical destruction of malignancy. Combined with the metabolic information from FDG PET, CT offered superior osseous characterization versus MRI in this cohort, a conclusion the authors state explicitly and one that should guide clinicians choosing the most efficient follow-up test for an incidental orbital hot spot.

The Beijing team is careful not to advocate for total neglect. Their conclusion endorses individualized imaging surveillance, an approach tailored to each patient’s cancer history, lesion characteristics, and risk profile, rather than a blanket policy of either reflexive biopsy or reflexive dismissal. The five patients with metastatic disease and the single sphenoid metastasis with cortical destruction underscore that context matters: in a patient with widespread progressive malignancy, an orbital focus demands closer scrutiny than the same focus in a patient with degenerative disease and stable imaging elsewhere. But the central message of the study is clear and, for thousands of future patients, genuinely comforting. The small round light beside the eye on a bone scan is, in the vast majority of cases, not a spreading cancer but a quiet quirk of bone biology, a lesion that has likely sat there harmlessly for years and will still be sitting there, unchanged, years from now. In the high-stakes world of oncological imaging, that kind of evidence-based reassurance is worth its weight in technetium.

Subject of Research: Incidental orbital radionuclide uptake on bone scintigraphy and its benign etiology

Article Title: Benign nature of incidental orbital uptake on bone scintigraphy: insights from multi-modality imaging and follow-up

Article References: Song, L., Guo, N., & Zhang, W. (2026). Benign nature of incidental orbital uptake on bone scintigraphy: insights from multi-modality imaging and follow-up. BMC Medical Imaging. https://doi.org/10.1186/s12880-026-02844-9

Image Credits: AI Generated

DOI: 10.1186/s12880-026-02844-9

Keywords: bone scintigraphy, orbital lesions, incidental findings, fibrous dysplasia, Bone-RADS, FDG PET/CT, MRI, SUVmax, metastasis, nuclear medicine, multimodal imaging, ground-glass opacity