The researchers then used D-dimer concentration and headache severity to stratify fracture-positive patients into groups with different imaging yields. Because the strategy was derived and evaluated in the same hospital cohort, the findings are exploratory and require prospective external validation before routine clinical use. The strategy addresses a complication that can be difficult to detect after head injury. tCVST occurs when trauma causes thrombotic occlusion of a dural venous sinus or large cerebral vein.

Mechanical injury to the sinus wall can disrupt the endothelium and initiate local coagulation, while obstruction of venous outflow may impair cerebrospinal fluid absorption, increase intracranial pressure and produce cerebral venous congestion. Thrombosis can extend to adjacent cortical veins, and elevated downstream venous pressure may contribute to venous infarction with hemorrhagic transformation. Standard non-contrast head CT and CT angiography designed to assess arterial injury may fail to visualize sinus thrombus, particularly with partial occlusion or subtle hyperdensity mistaken for imaging artifact.

Dedicated CT venography or MR venography provides a more direct assessment, but routine venous imaging is not standard in most traumatic brain injury protocols. Most research on tCVST has focused on severe brain injury, particularly cases with skull fractures near a venous sinus and patients requiring neurosurgical care. The study examined a less severely injured population: adults whose Glasgow Coma Scale score was above 8, corresponding to the mild-to-moderate range of 9 to 15.

Its first step was to inspect high-resolution CT bone-window images for a linear or comminuted fracture line traversing the anatomical course of the superior sagittal, transverse, sigmoid or straight sinus. A neuroradiologist blinded to venographic findings and the final tCVST diagnosis classified 100 patients as fracture-positive and 428 as fracture-negative. Among patients without the fracture, 16 of 428 had tCVST, while 25 of 100 fracture-positive patients had the complication.

That distribution made trans-sinus fracture a potentially useful gatekeeper but an incomplete risk marker on its own. It identified 25 of the 41 tCVST cases, giving 61.0% sensitivity and 89.1% specificity, while its negative predictive value was 96.3%. The positive likelihood ratio was 3.96, and the negative likelihood ratio was 0.46.

However, 16 cases occurred without a visible trans-sinus fracture, showing that the absence of this fracture would not exclude tCVST in every patient. Conversely, most fracture-positive patients did not have tCVST, meaning that imaging everyone with such a fracture would still produce many negative examinations. The authors therefore proposed using the fracture as an initial filter, followed by risk stratification rather than as a stand-alone diagnostic finding or automatic imaging command.

The second step assessed two readily available measurements only in fracture-positive patients. A patient was classified as high risk if D-dimer was at least 3.95 mg/L fibrinogen equivalent units or headache intensity was at least 3 on a 0-to-10 scale; both measurements had to fall below those cutoffs for a patient to enter the lower-risk group. D-dimer was measured within 24 hours of admission before antithrombotic administration, and the 3.95 mg/L threshold was the median among fracture-positive patients rather than an independently validated clinical threshold.

Headache was recorded at admission with a 100-mm visual analog scale, with a score of 3 corresponding to 30 mm. This “either-or” rule classified 77 patients as high risk, 24 of whom had tCVST, a detection rate of 31.2%. The 23 lower-risk patients included one case, or 4.3%.

When the two variables were examined in separate combinations, the highest observed yield occurred among fracture-positive patients with both elevated D-dimer and a headache score of at least 3: 16 of 29, or 55.2%, had tCVST. By comparison, the group with low D-dimer and a headache score below 3 had one case among 23, and those with high D-dimer but a lower headache score had one among 21, or 4.8%. These observations describe how two clinical measurements refined the observed probability of thrombosis after an anatomical risk signal had been identified.

The largest numerical attraction of the strategy was its change in imaging efficiency. If all 528 patients had undergone venous imaging, 41 cases would have been detected with a number needed to image of 13, corresponding to 13 examinations for each case found. Imaging every fracture-positive patient would require four examinations per detected case.

Restricting imaging to the 77 high-risk patients reduced the number needed to image to three and avoided 451 examinations classified by the researchers as unnecessary, or 85.4% of the total imaging volume. This efficiency came with a cost: the complete two-step pathway detected 24 of 41 cases, corresponding to 58.5% sensitivity, and would therefore have missed 17 cases. The reported 96.3% negative predictive value for Step 1 was also calculated in a cohort with a 7.8% detection yield, so predictive values could differ in unselected trauma populations.

The cohort itself limits how the results can be interpreted. These were not consecutive patients with mild-to-moderate brain injury. They were 528 of 566 adults who had already undergone CT venography, MR venography or selected digital subtraction angiography because their treating neurosurgeons suspected possible venous injury.

The study therefore measures diagnostic performance within an imaging-enriched population, not the true incidence of tCVST among everyone with mild-to-moderate traumatic brain injury. It was conducted retrospectively at one tertiary hospital in Shaanxi, China, from January 2024 through January 2026. Forty-one of the 528 included patients had tCVST, and 16 of the 41 cases lacked trans-sinus fracture.

Treatment decisions, including anticoagulation, were not standardized, and long-term functional recovery, thrombus recanalization and hemorrhagic complications were not systematically assessed. Several questions must be answered before the approach could become a clinical rule. Prospective multicenter studies would need to enroll consecutive patients, standardize fracture assessment, D-dimer collection and venographic timing, and determine whether deferring imaging in fracture-negative patients is safe.

The 16 fracture-negative tCVST cases also require detailed characterization to identify additional risk signals not captured by the strategy. A cost-effectiveness analysis would need to compare the two-step approach with universal screening and current discretionary practice, while the data-derived D-dimer cutoff would require confirmation in independent populations. The two-step pathway was developed and evaluated in the same sample, so its sensitivity, specificity, predictive values and efficiency estimates are likely optimistic.

Until external validation establishes its performance and safety, the results remain a hypothesis-generating decision aid: a CT-visible trans-sinus fracture opens the pathway, while D-dimer and headache thresholds refine the selection of patients for dedicated venous imaging without replacing clinical judgment.

Subject of Research: Exploratory two-step selection of venous imaging for traumatic cerebral venous sinus thrombosis after mild-to-moderate traumatic brain injury

Article Title: Trans-sinus fracture as the gatekeeper: a two-step clinical strategy to guide venous imaging in mild-to-moderate traumatic brain injury

Article References: Zhan, J., Chen, X., Liu, B., Zhou, X., Xu, D., & Wu, Z. (2026). Trans-sinus fracture as the gatekeeper: a two-step clinical strategy to guide venous imaging in mild-to-moderate traumatic brain injury. Frontiers in Neurology, 17, Article 1901656. https://doi.org/10.3389/fneur.2026.1901656

Image Credits: AI Generated

DOI: 10.3389/fneur.2026.1901656

Keywords: traumatic brain injury, cerebral venous sinus thrombosis, trans-sinus fracture, CT venography, MR venography, D-dimer, headache severity, diagnostic imaging, clinical decision rule, retrospective cohort, Trans-sinus, fracture

The grant supports ongoing development and testing; the announcement does not present the platform as a completed clinical technology or report outcomes in patients. PET radiotracers are compounds that combine a tiny amount of radioactive material with a biological molecule designed to seek a specific target in the body, such as a protein found on cancer cells. Once injected, the radioactive signal is detected by a PET scanner, which creates an image showing where the tracer has accumulated.

Unlike imaging methods that primarily show anatomical structures, PET can reveal biological activity inside the body, including the presence and location of particular molecules or processes and changes over time. The project addresses a bottleneck in translational imaging: scientists can identify promising biological markers more quickly than they can convert them into usable PET tracers. Incorporating radioactive material into a candidate molecule is time-consuming and technically demanding, requiring specialized equipment and facilities.

The USC team’s platform is intended to reduce that production burden by pairing a universal radioactive building block with different biological molecules. In principle, the same compact setup could generate several tracer candidates rather than requiring a separate production configuration for every compound. The announced work focuses on developing that approach, not on an already validated system for routine clinical use.

At the center of the platform are two radiochemistry approaches: click chemistry, which allows molecules to be joined quickly, and droplet radiochemistry, which carries out chemical reactions in extremely small droplets and therefore uses tiny amounts of material. Kai Chen, PhD, a professor of research radiology, radiation oncology, and pharmacology and pharmaceutical sciences at USC, is leading the project with collaborators at UCLA. The device they are building uses a tiny chip to combine the universal radioactive building block with selected biological molecules.

Chen said concentrating the process on the chip could enable radiotracers to be produced rapidly and efficiently, with less reliance on traditional large-scale equipment and dedicated facilities. Preliminary research suggests that the approach can generate radiotracers for multiple cancer biomarkers on a very small scale. One candidate is designed to target fibroblast activation protein, which is found at high levels in many tumors.

The team is also testing tracers intended specifically to detect liver and prostate cancer. Chen said these findings show that click chemistry can rapidly generate tracers for multiple cancer biomarkers and that the compounds can be produced at miniature scale. The results provide early evidence for the platform’s underlying chemistry, but the announcement does not report human diagnostic performance, improved clinical outcomes or a final device ready for routine use.

The next one to two years of the funded project are expected to focus on optimizing the compact device and testing a broader range of radiotracers. The researchers plan to compare some candidates with established tracers to determine how well they perform. After that testing, the team intends to build and refine the final device, conduct quality control and complete preclinical testing before working toward clinical applications.

These are planned stages of the research program. The grant announcement therefore supports a development roadmap involving optimization, comparative evaluation, quality control and preclinical assessment rather than a completed demonstration of clinical benefit. If the platform succeeds, automating and simplifying radiotracer production could lower costs and reduce the resources required to create new tracers.

The USC team says this could make it possible to produce a wider range of customized tracers and potentially expand access to PET imaging. More specialized agents could allow researchers and medical providers to examine molecular features of tumors and track changes over time. Such information could help assess treatment response earlier and more precisely, potentially indicating sooner whether a therapy is working or whether a different approach is needed.

Those benefits are possibilities that depend on successful development and validation of particular tracers, not outcomes already established by the grant-funded project. The modular platform may also be adapted beyond cancer. The researchers are considering uses for radiotracers targeting conditions including neurological diseases, reflecting the broader objective of expanding PET imaging into additional areas of medicine.

Because the construction combines a reusable radioactive building block with biological molecules designed for different targets, the system could support more than one type of tracer. The supplied announcement does not report completed neurological studies or patient cohorts, so that application remains prospective. It also does not establish how broadly the platform could be deployed or what effect it will ultimately have on PET availability.

The program brings together imaging science, chemistry and engineering, with support from NIH grant R01EB040161. Joshua Hirsch, MD, chair of USC’s Department of Radiology and the Stewart Dale Fordham, MD, Chair in Radiology, said the award recognizes the team’s innovative work and its potential to make advanced molecular imaging more accessible, accelerate radiotracer development and ultimately provide better tools for diagnosis and personalized treatment. Those statements describe the anticipated impact of the project.

The demonstrated work to date consists of a miniaturized radiochemistry concept supported by preliminary radiotracer-generation results, while optimization, broader tracer testing, preclinical evaluation and subsequent clinical development remain ahead.

Subject of Research: A compact radiochemistry platform for producing PET radiotracers targeting cancer biomarkers.

Article Title: USC researchers launch effort to expand PET imaging for cancer and other diseases

Article References: USC researchers launch effort to expand PET imaging for cancer and other diseases. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: PET imaging, radiotracers, radiochemistry, cancer imaging, click chemistry, droplet radiochemistry, molecular imaging, USC, NIH funding, diagnostic imaging, researchers, launch

The study enrolled patients hospitalized with pathologically confirmed intraductal breast lesions at one hospital from April 2025 to April 2026. The cohort included 132 benign cases and 68 malignant cases. Every participant underwent both conventional two-dimensional ultrasound and automated breast ultrasound, or ABUS.

Investigators compared ultrasonographic features between the benign and malignant groups, then applied univariate and multivariate logistic regression to identify independent risk factors and construct a combined diagnostic model. Investigators used receiver operating characteristic curves to compare the diagnostic efficiency of the combined model with the two imaging approaches evaluated separately. Malignant lesions differed from benign lesions in several ultrasound features.

The malignant group had significantly higher incidences of irregular shape, microcalcification, abundant blood flow, duct dilatation of at least 5 mm, a convergence sign, lesion extension toward the nipple, and marginal spiculation or angulation. Each of these seven associations was statistically significant at P < 0.05, and multivariate logistic regression identified them as independent risk factors for malignancy. The model’s imaging variables therefore captured several distinct aspects of lesion appearance: irregular morphology, the presence of microcalcification, blood flow classified as Adler grade II–III, duct dilatation of at least 5 mm, convergence of tissue features, extension toward the nipple, and spiculation or angulation at the margin.

The analysis linked their combined presence with the likelihood that a pathologically confirmed lesion was malignant. The results indicate that ABUS and conventional two-dimensional ultrasound together produced favorable diagnostic performance for preoperative benign–malignant differentiation of intraductal breast lesions. In the studied population, the combined approach performed better than either examination alone according to the reported area under the curve.

The study therefore supports the combined use of the two ultrasound methods as an imaging aid for this specific group of lesions, rather than establishing a general benefit across all types of breast abnormalities. Several features of the study limit how broadly the findings can be interpreted. It was conducted in a single hospital and included 200 hospitalized patients with pathologically confirmed intraductal breast lesions, including 68 malignant cases.

The model was developed and evaluated in that same single-center cohort, and the supplied results do not establish performance in other hospitals, screening populations, or patients with a wider range of breast findings. Because the study was limited to one institution and a relatively small malignant subgroup, the combined model’s diagnostic performance should be viewed as specific to the evaluated cohort. The reported AUC, sensitivity, and specificity quantify performance in this sample; they do not by themselves demonstrate that the model will maintain the same results in external populations.

Further evidence would be needed to determine how consistently the approach performs across different clinical settings. Overall, the study found that combining automated and conventional ultrasound produced the strongest reported discrimination between benign and malignant intraductal breast lesions. The analysis linked improved classification to seven ultrasound characteristics identified as independent risk factors in the cohort.

Its findings offer an imaging-based model for preoperative assessment in hospitalized patients with pathologically confirmed intraductal lesions, while the single-center design defines the boundary of the evidence.

Subject of Research: Preoperative ultrasound diagnosis of intraductal breast lesions

Article Title: Diagnostic value of combined automated breast ultrasound system and conventional two-dimensional ultrasound for intraductal breast lesions

Article References: Yang, Q., Yi, R., Guo, F., Gou, T., Cai, L., Wang, S., Zhang, Y., & Luo, Y. (2026). Diagnostic value of combined automated breast ultrasound system and conventional two-dimensional ultrasound for intraductal breast lesions. BMC Medical Imaging. https://doi.org/10.1186/s12880-026-02832-z

Image Credits: AI Generated

DOI: 10.1186/s12880-026-02832-z

Keywords: ABUS, breast ultrasound, intraductal lesions, breast cancer, diagnostic imaging, two-dimensional ultrasound, microcalcification, duct dilatation, logistic regression, diagnostic accuracy, Diagnostic, value

The dog arrived at the veterinary teaching hospital with a hemorrhagic, ulcerative lesion on the back of its right elbow that the owner had first noticed three weeks earlier. Initial cytological examinations, including an impression smear and fine needle aspiration, revealed bacterial infection and atypical cells with concerning features such as marked variation in cell and nuclear size, but no definitive mesenchymal tumor cells could be identified. The atypical epithelioid-appearing cells were interpreted as likely reactive changes associated with the ulcerated wound rather than the underlying malignancy. Empirical antimicrobial and antifungal treatment was started, but the lesion failed to respond and instead rapidly enlarged into a distinct mass.

A biopsy was then performed, and histopathological examination revealed spindle-shaped cells with pleomorphic nuclei within the subcutaneous tissue, consistent with a soft tissue sarcoma. Using the standard three-tiered grading system for canine soft tissue sarcomas, which combines differentiation, mitotic activity, and necrosis into a summed score, the tumor was assigned a grade 2. In general terms, grade 2 soft tissue sarcomas carry a median survival of one to two years and a metastasis rate of up to twenty percent, so the clinical team expected a moderately aggressive but manageable disease. Yet the lesion was progressing faster than such a grade would typically suggest, prompting the clinicians to look deeper.

That deeper look came in the form of 18F-FDG PET/CT, a hybrid imaging modality that merges the anatomical detail of computed tomography with the functional insight of positron emission tomography. The technique relies on a radiolabeled glucose analog that accumulates in tissues with high metabolic activity, a hallmark of many malignant tumors. The dog received an intravenous injection of 239.02 megabecquerels of the tracer, equivalent to 6.29 megabecquerels per kilogram of body weight, followed by a sixty-minute uptake period before scanning. The resulting images showed intense tracer accumulation within the elbow mass, yielding a maximum standardized uptake value of 10.1 and a mean standardized uptake value of 4.6. Critically, no abnormal tracer-avid lesions were detected elsewhere in the body, including the regional lymph nodes, ruling out distant metastasis and confirming the elbow mass as the primary tumor.

Surgical resection was performed approximately two weeks after the PET/CT scan, and the excised tissue underwent definitive histopathological analysis. The results were sobering: the tumor was a poorly differentiated mesenchymal neoplasm with a mitotic count exceeding forty figures per ten high-power fields, producing a summed grade of 3, the most aggressive category. Moreover, the excision was incomplete, with neoplastic cells extending to the deep surgical margin. The preoperative biopsy had therefore underestimated the final tumor grade, while the high fluorodeoxyglucose avidity observed on PET/CT aligned far more closely with the tumor’s true biological behavior. Immunohistochemical staining for desmin and alpha smooth muscle actin, both markers of smooth muscle differentiation, confirmed the diagnosis of subcutaneous leiomyosarcoma, a rare malignancy arising from smooth muscle cells.

Leiomyosarcoma in dogs most commonly originates in visceral organs such as the gastrointestinal tract, liver, or uterus, where it carries a poor prognosis with a reported median survival of roughly ten months. Non-visceral forms, including cutaneous and subcutaneous variants, are far less common and remain poorly characterized. Some researchers argue that subcutaneous leiomyosarcoma should be classified independently from conventional soft tissue sarcomas because of its distinct biological behavior and anatomical location. In human medicine, subcutaneous leiomyosarcoma is considered more aggressive than its purely cutaneous counterpart, with higher local recurrence rates and a worse clinical course, though whether the same distinction holds in dogs remains uncertain due to the scarcity of published cases.

The PET/CT findings in this case are notable when compared against benchmarks from human oncology. In human soft tissue sarcomas, maximum standardized uptake values have been reported at averages of 1.3, 2.7, and 4.5 for grades 1, 2, and 3 respectively, with thresholds of 3.9 for the maximum value and 2.5 for the mean proposed to separate grade 2 and 3 tumors from grade 1. The dog’s maximum value of 10.1 exceeded even the reported human range for grade 3 tumors. The only prior veterinary PET/CT study of canine soft tissue sarcomas documented maximum values between 2.0 and 10.6, but tumor grades were not recorded, limiting direct comparison. A single earlier report of canine leiomyosarcoma, a grade 1 gastric tumor, recorded a maximum value of 6.234, substantially lower than the 10.1 observed in this grade 3 subcutaneous case, suggesting a possible relationship between tracer uptake and histologic grade in this tumor type as well.

The clinical outcome underscored the accuracy of the metabolic signal. Although limb amputation and adjuvant chemotherapy were recommended following the grade 3 diagnosis with incomplete margins, the owner declined both options and opted for palliative care with prednisolone and analgesics. One month after surgery, thoracic radiographs showed no metastatic lesions. But three months postoperatively, the dog developed a cough, and imaging revealed a pulmonary nodule alongside local tumor recurrence at the surgical site. Follow-up imaging three weeks later showed both the size and number of lung nodules increasing. The dog expired six months after surgery, a course consistent with the poor prognosis associated with high-grade tumors and incomplete resection, and one that vindicates the early warning provided by the PET/CT scan.

The case carries important implications for veterinary oncology practice. Because soft tissue sarcomas are biologically heterogeneous, preoperative biopsies can misgrade tumors, with studies showing that pretreatment biopsy does not always reflect the true grade due to intratumoral heterogeneity. Such underestimation can lead to suboptimal surgical planning, inadequate margins, and missed opportunities for aggressive intervention. In this case, the markedly elevated fluorodeoxyglucose uptake served as a functional red flag that the tumor was more dangerous than its biopsy grade implied, supporting the argument for more proactive management such as amputation, adjuvant chemotherapy, and intensified postoperative surveillance when PET/CT reveals high metabolic activity.

The researchers acknowledge limitations inherent to a single case report. Fluorodeoxyglucose is not tumor-specific, and the active purulent inflammation within the ulcerated lesion may have contributed to the elevated uptake, although the authors argue that inflammation alone is unlikely to explain the magnitude of the signal. Additional immunohistochemical markers for smooth muscle differentiation, such as h-caldesmon and calponin, were not evaluated, and Ki-67 proliferative staining was not performed. The suspected pulmonary metastases were never histologically confirmed, though their progressive growth on serial radiographs was highly suggestive. Even so, as the first documented application of 18F-FDG PET/CT to canine subcutaneous leiomyosarcoma, the report opens a window onto a diagnostic approach long established in human sarcoma care and now demonstrating its value in veterinary medicine, where metabolic imaging may soon complement the scalpel and the microscope in deciding how hard to fight a tumor that biopsy alone cannot fully characterize.

Subject of Research: Use of 18F-FDG PET/CT imaging to assess tumor aggressiveness in canine subcutaneous leiomyosarcoma

Article Title: Case Report: 18F-FDG PET/CT for precision assessment of tumor aggressiveness in canine subcutaneous leiomyosarcoma

Article References: Chae, Y., Lee, D., Koo, Y., Yun, T., Kim, H., & Kang, B.-T. (2026). Case Report: 18F-FDG PET/CT for precision assessment of tumor aggressiveness in canine subcutaneous leiomyosarcoma. Frontiers in Veterinary Science, 13, Article 1948200. https://doi.org/10.3389/fvets.2026.1948200

Image Credits: AI Generated

DOI: 10.3389/fvets.2026.1948200

Keywords: 18F-FDG PET/CT, leiomyosarcoma, soft tissue sarcoma, veterinary oncology, tumor grading, diagnostic imaging, canine cancer, standardized uptake value, immunohistochemistry, case report, metabolic imaging, surgical margins

The case, reported by Lamya Eissa of Alexandria Faculty of Medicine, Esra’a Alyateem of the University of Jordan, and Hassan Magdy Abdelrazek of Mansoura University, describes a completely thrombosed mycotic pseudoaneurysm of the cervical internal carotid artery in a malnourished child. A mycotic aneurysm, despite its name, has nothing to do with fungal infection in most cases; the term refers to an infected, weakened segment of an artery wall that balloons outward under arterial pressure. When such a lesion fills with clot, it loses the flowing blood signal that normally gives it away on imaging, and instead presents as a solid-appearing mass that can be nearly indistinguishable from a collection of pus.

Parapharyngeal abscesses are relatively rare in children but carry serious risk. The parapharyngeal space is a deep compartment of the neck bounded by critical structures, including the carotid sheath, which houses the internal carotid artery, the internal jugular vein, and cranial nerves. Infection in this space can spread along fascial planes toward the mediastinum, and documented vascular complications include arterial narrowing, pseudoaneurysm formation, and ischemic stroke. Prior literature, cited in the report, has described internal carotid artery pseudoaneurysms arising secondary to retropharyngeal and parapharyngeal abscesses, as well as carotid mycotic pseudoaneurysms masquerading as peritonsillar abscesses in pediatric patients.

The danger in this specific scenario is mechanical as much as infectious. If a surgeon incises what appears to be an abscess but is actually an aneurysm, the result can be catastrophic hemorrhage. A pseudoaneurysm is a false aneurysm: blood escapes through a defect in the arterial wall and is contained not by the vessel’s own layers but by surrounding tissue, forming a fragile sac. The classic ultrasound signature of a patent pseudoaneurysm is the so-called to-and-fro waveform, in which blood surges into the sac during systole and back into the artery during diastole. But when the sac is completely thrombosed, that diagnostic flow pattern vanishes, and the lesion becomes a silent impostor.

That is precisely what happened in this child. The initial contrast-enhanced CT was suboptimal, and it suggested an abscess rather than a vascular lesion. Only when the team pursued dedicated, high-quality multimodal imaging did the true nature of the mass emerge. The workup included magnetic resonance imaging with diffusion-weighted imaging and apparent diffusion coefficient mapping, magnetic resonance angiography, and three-dimensional CT angiography. Each modality contributed a different piece of evidence, and together they overturned the working diagnosis before a scalpel ever touched the neck.

The technical logic of this multimodal approach is worth unpacking. Diffusion-weighted imaging is exquisitely sensitive to restricted water diffusion, which is characteristic of pus-filled abscess cavities; on apparent diffusion coefficient maps, abscesses typically show marked hypointensity because the viscous, cellular contents of pus impede the random motion of water molecules. A thrombosed aneurysm, by contrast, contains organized clot whose diffusion characteristics differ from those of an abscess. Magnetic resonance angiography visualizes flowing blood without ionizing radiation and can demonstrate the absence of flow within the lesion as well as the relationship of the mass to the parent internal carotid artery. Three-dimensional CT angiography then provides high-resolution anatomical mapping of the cervical vasculature, delineating the aneurysm’s origin, size, and spatial relationship to the skull base and surrounding structures.

The case also highlights the role of the child’s nutritional status. Malnutrition is known to impair immune function and tissue integrity, and the report’s authors note that the patient was malnourished at presentation. Infected aneurysms in children are rare, and when they occur, they are often secondary to bacteremia, local infection spread, or, as in documented cases, deep neck abscesses eroding into the adjacent carotid artery. The report’s associated subject listings, which include primary herpetic gingivostomatitis and meningitis among related topics, reflect the infectious context in which such vascular complications arise.

What makes this case report valuable to clinicians is not the rarity of the lesion alone but the specificity of the imaging lesson it delivers. Complete thrombosis transforms a mycotic pseudoaneurysm into a mass that can easily be mistaken for an abscess without the right imaging modalities and high-quality imaging, the authors conclude. In practical terms, this means that when a deep neck mass in a child does not behave as expected, when contrast enhancement is suboptimal, or when the anatomical relationship to the carotid sheath is unclear, the workup should escalate to dedicated MRI with diffusion-weighted sequences, MR angiography, and CT angiography rather than proceeding to incision and drainage on the basis of a single imperfect scan.

The stakes of that escalation are enormous. Misdiagnosed and incised, an infected carotid pseudoaneurysm can exsanguinate a patient within minutes, and even when recognized, management is complex, often requiring endovascular or surgical intervention combined with prolonged antimicrobial therapy. Recognized vascular complications of deep neck infections also include internal carotid artery narrowing, as documented in children with retropharyngeal lymphadenitis and abscess, and ischemic stroke secondary to carotid pseudoaneurysm, as reported in the pediatric literature. The parapharyngeal space’s proximity to the carotid sheath means that every deep neck infection carries at least a theoretical vascular risk, and this case demonstrates how that theoretical risk can become a concrete diagnostic trap.

For the broader radiology and pediatric communities, the case reinforces a principle that imaging specialists have long championed: no single modality is definitive, and the diagnosis of a deep neck mass in a child demands correlation across clinical findings, laboratory data, and complementary imaging techniques. The authors’ contribution statement indicates that the work encompassed conceptualization, imaging analysis, study design, and figure preparation, with all authors reviewing and approving the final version. Conducted in accordance with the Declaration of Helsinki and published with informed parental consent, the report adds a well-documented data point to a small but clinically critical literature. As deep neck infections continue to present in emergency departments worldwide, this child’s story stands as a warning that the most familiar diagnosis is not always the correct one, and that the tools to see the difference already exist for those who know to reach for them.

Subject of Research: Pediatric Radiology

Article Title: Thrombosed mycotic aneurysm of the cervical internal carotid artery mimicking a parapharyngeal abscess in a child: a case report of multimodal imaging diagnosis

Article References: Eissa, L., Alyateem, E., & Abdelrazek, H. M. (2026). Thrombosed mycotic aneurysm of the cervical internal carotid artery mimicking a parapharyngeal abscess in a child: a case report of multimodal imaging diagnosis. Pediatric Radiology. https://doi.org/10.1007/s00247-026-06814-9

Image Credits: AI Generated

DOI: 10.1007/s00247-026-06814-9

Keywords: mycotic aneurysm, pseudoaneurysm, internal carotid artery, parapharyngeal abscess, deep neck infection, multimodal imaging, diffusion-weighted MRI, CT angiography, pediatric radiology, thrombosis, case report, diagnostic imaging

The study, published in Frontiers in Oncology by Mengze Liu, Dandan Li of Weifang People’s Hospital and Zhanqiang Jin of the University of South China, tackles a well-known weakness in the American College of Radiology’s Ovarian-Adnexal Reporting and Data System for ultrasound, known as O-RADS US. That framework asks sonographers to describe an ovarian mass in standardized terms—whether it is a simple cyst or a complex lesion, whether its walls are smooth or irregular, whether it contains solid components or papillary projections, and how much blood flow it shows on Doppler imaging—and then assigns the lesion to a category that carries an estimated risk of malignancy. Category 2 lesions carry less than a 1 percent risk, Category 3 lesions between 1 and 10 percent, Category 4 lesions between 10 and 50 percent, and Category 5 lesions 50 percent or more. The problem is that Category 4, the intermediate zone, spans an enormous range of risk, and the entire system depends on the subjective judgment and experience of the person holding the ultrasound probe.

To inject objectivity into that gray zone, the researchers turned to blood. They integrated the Risk of Ovarian Malignancy Algorithm, or ROMA, a U.S. Food and Drug Administration-approved calculation that combines two serum biomarkers—cancer antigen 125 (CA125) and human epididymis protein 4 (HE4)—with the patient’s menopausal status. CA125 has been a staple of ovarian cancer diagnostics for decades, but it rises in pregnancy, menstruation, endometriosis and inflammatory pelvic disease, giving it poor specificity. HE4, a more recently adopted marker, complements CA125 because it is less often elevated in those benign conditions, though smoking and contraceptive use can shift its levels too. Neither marker alone is sensitive or specific enough for early detection, but evidence has consistently supported pairing them. ROMA packages that pairing into a single probability score, adjusted for the fact that postmenopausal women face inherently higher baseline risk.

The team’s hybrid approach was elegantly simple. They first classified 159 ovarian-adnexal masses in 151 patients using standard O-RADS US criteria, with two sonographers of more than ten years’ experience each independently reviewing the images, blinded to all biomarker results, and a third senior examiner resolving disagreements. They then measured CA125 and HE4 in preoperative blood samples, calculated each patient’s ROMA value, and compared it against a diagnostic threshold derived from receiver operating characteristic analysis: 29.70 for premenopausal women and 42.50 for postmenopausal women. Depending on how far a patient’s ROMA score exceeded that threshold, the lesion’s O-RADS category was nudged up or down. A ROMA value exceeding the threshold by 10 percent or more escalated a Category 3 or 4 lesion to Category 4 or 5, while values below the threshold could demote intermediate-risk lesions into safer categories.

The results were striking. The modified system achieved an area under the receiver operating characteristic curve—a standard measure of diagnostic discrimination where 1.0 is perfect—of 0.922, significantly better than the original O-RADS US score of 0.815 and better than ROMA alone in any patient group. In practical terms, the malignancy rate among lesions classified as high-risk (Categories 4 and 5) rose from 44.0 percent under the original system to 58.1 percent under the modified one, meaning the high-risk pool became far more concentrated with true cancers. Meanwhile, the proportion of lesions languishing in the ambiguous Category 4 shrank from 29.5 percent to 15.1 percent, as many were confidently reassigned to lower-risk Categories 2 or 3. Category 5 lesions, the most worrisome, remained essentially stable at around 23 to 24 percent, suggesting the biomarker integration did not destabilize the system’s most confident calls.

The reclassification patterns reveal how the hybrid system behaves at the level of individual patients. Of the 47 lesions originally placed in Category 4, 26 were downgraded to Category 3 and only one of those proved malignant on final histopathology, while 14 were upgraded to Category 5 and seven of those were indeed cancers. Among the 30 original Category 3 lesions, all 20 that were downgraded to Category 2 turned out to be completely benign. The trade-off came in sensitivity: the modified system detected 82.1 percent of cancers compared with 92.3 percent for the original, but its specificity jumped from 60.0 percent to 92.5 percent. In a clinical context where false positives trigger surgery and false negatives can be catastrophic, that rebalancing matters enormously—it means far fewer benign masses would be sent down the invasive diagnostic pathway.

The study cohort itself reflected the diagnostic challenge. Of the 159 masses, 111 were benign—ranging from serous and mucinous cystadenomas to endometriosis cysts, fibromas and benign teratomas—11 were borderline tumors, and 37 were malignant, including high-grade and low-grade serous carcinomas, mucinous carcinomas, clear cell carcinoma and endometrioid carcinoma. Malignant lesions were also significantly larger, with a median diameter of 11.0 centimeters compared with 7.35 centimeters for benign masses, and carried markedly higher levels of CA125, HE4 and ROMA scores. The ROMA thresholds identified in this cohort yielded sensitivities and specificities of 80.6 percent and 76.8 percent in premenopausal women and 88.0 percent and 78.5 percent in postmenopausal women, broadly consistent with the 76 to 86 percent sensitivity and 74 to 95 percent specificity reported in prior meta-analyses.

The significance of this work lies in its attempt to fuse two diagnostic philosophies that have historically operated in parallel. O-RADS US captures the morphology and vascularity of a lesion—what the tumor looks like—while ROMA captures its molecular signature—what the tumor is secreting. A recent meta-analysis found the original O-RADS US system achieves a robust pooled sensitivity of 97 percent but only moderate specificity of 77 percent, precisely the profile that generates anxiety-inducing intermediate classifications and unnecessary operations. By letting a validated biomarker algorithm arbitrate the ambiguous middle of the risk spectrum, the modified framework converts subjective uncertainty into quantified probability. The authors suggest this could reduce unnecessary biopsies and surgeries for low-to-moderate risk lesions, a meaningful benefit given the physical, emotional and financial costs of adnexal surgery.

Important caveats temper the enthusiasm. The study was retrospective and single-center, and the ROMA thresholds were derived from the same patient cohort in which the new system was then tested—a methodological circularity that risks overfitting and an overly optimistic estimate of accuracy. Classic benign lesions such as simple cysts were excluded, introducing selection bias, and there was no independent validation cohort or formal interobserver assessment. The authors themselves call for prospective observational studies across diverse populations before the modified system enters clinical practice. Still, the concept is compelling: if larger, multi-center trials confirm these findings, the humble combination of an ultrasound examination and two blood tests could become a markedly more reliable gatekeeper, catching more of the ovarian cancers that matter while letting benign masses rest undisturbed.

Subject of Research: Integration of the ROMA biomarker algorithm into the O-RADS ultrasound system for risk stratification of ovarian carcinoma

Article Title: A modified ovarian-adnexal reporting and data system ultrasound for differentiating ovarian carcinoma: integration of the risk of malignancy algorithm into the American College of Radiology’s O-RADS US framework

Article References: Liu, M., Li, D., & Jin, Z. (2026). A modified ovarian-adnexal reporting and data system ultrasound for differentiating ovarian carcinoma: integration of the risk of malignancy algorithm into the American College of Radiology’s O-RADS US framework. Frontiers in Oncology, 16, Article 1962862. https://doi.org/10.3389/fonc.2026.1962862

Image Credits: AI Generated

DOI: 10.3389/fonc.2026.1962862

Keywords: ovarian cancer, O-RADS US, ROMA, CA125, HE4, transvaginal ultrasound, biomarkers, risk stratification, diagnostic imaging, gynecologic oncology, adnexal masses, early detection

The study, published in BMC Medical Imaging, addresses a long-standing tension in lymphoma staging. Diffuse large B-cell lymphoma, the most common aggressive non-Hodgkin lymphoma in adults, is staged in part by determining whether the disease has spread to the bone marrow. For decades, the only way to answer that question definitively was the iliac crest biopsy, a procedure that samples just a tiny fraction of the total marrow volume. Meanwhile, positron emission tomography using the radioactive glucose analog fluorodeoxyglucose offers a whole-body view of metabolic activity, because rapidly dividing lymphoma cells consume glucose voraciously and light up on the scan. The problem has always been knowing when a bright signal in the marrow truly means cancer rather than something benign.

The Korean team, led by Sang Jun Byun and Yunhwi Hwang, who contributed equally to the work, with corresponding author Byungwook Choi, proposed an elegantly simple solution: use the liver as an internal brightness yardstick. Two nuclear medicine physicians independently classified the uptake of the radioactive tracer in both the bone marrow and the spleen as either High or Low relative to the liver’s own signal. If either organ appeared brighter than the liver — or if either showed focal, localized hot spots — the case was labeled “Any High.” If both organs stayed dimmer than the liver, the case was “Both Low.” The logic is rooted in lymphoma biology: the spleen, like the marrow, is a lymphoid organ where disseminated disease tends to lodge, so simultaneous metabolic activation in both sites is far more suspicious than activation in either alone.

To test the rule, the researchers assembled a primary diagnostic cohort of 107 patients with newly diagnosed diffuse large B-cell lymphoma who had undergone both pretreatment PET/CT and adequate bone marrow biopsy. The biopsy came back positive in 18 of those patients. When the Any High classification was applied, it correctly identified 83.3 percent of the true positive cases — a sensitivity with a 95 percent confidence interval running from 58.6 to 96.4 percent. More importantly for patients hoping to avoid the needle, the rule correctly cleared 80.9 percent of the true negatives, yielding a specificity of 71.2 to 88.5 percent. The negative predictive value — the probability that a Both Low result truly means the marrow is clean — reached an extraordinary 96.0 percent, with a confidence interval of 88.8 to 99.2 percent. Overall accuracy was 81.3 percent.

That negative predictive value is the number that matters most clinically. In this cohort, only 3 of the 75 patients classified as Both Low actually harbored marrow involvement. In other words, if a patient’s PET scan showed subdued marrow and splenic activity relative to the liver, there was a 96 percent chance the biopsy would find nothing. For the remaining small fraction, the biopsy would still catch the disease, but for the overwhelming majority, the painful procedure could potentially be skipped — pending the prospective validation the authors themselves insist is required before any change to clinical practice.

The researchers did not stop at the combined rule. They compared it against the simpler alternative of looking at the bone marrow alone. The combined Any High approach traded some specificity for sensitivity: it caught more true positives but flagged more false alarms. Yet the overall accuracy was statistically indistinguishable — 81.3 percent for the combined rule versus 82.2 percent for marrow alone, with an exact McNemar p value greater than 0.999. The team also ran a sensitivity analysis excluding patients whose marrow showed focal uptake, reducing the cohort to 94 patients with 12 biopsy-positive cases, and confirmed the estimates held. They even stress-tested the results by reclassifying or excluding two indeterminate biopsies, and the numbers remained robust.

Reproducibility is where many visual classification schemes in nuclear medicine collapse, but this one held up well. Inter-reader agreement between the two independent physicians was substantial to almost perfect for the principal criteria, with Cohen’s kappa values ranging from 0.750 to 0.843. The one soft spot was background splenic uptake, which showed lower agreement at kappa 0.648, compared with 0.773 for background marrow uptake. The spleen, it turns out, is a trickier organ to grade because its normal tracer uptake sits closer to the liver’s baseline, making the visual distinction more subtle. Still, the authors note that the combined classification itself — the decision that ultimately drives the clinical call — was highly reproducible.

Beyond diagnosis, the team explored whether the PET-based classification carried prognostic weight. In a separate cohort of 141 patients, they tracked progression-free survival and overall survival using Cox regression models. Over the follow-up period, 66 progression events and 49 deaths occurred. When adjusted for the International Prognostic Index — the standard clinical risk score incorporating factors such as age, stage, lactate dehydrogenase, and performance status — patients classified as Any High had roughly twice the hazard of progression or death compared with Both Low patients, with a hazard ratio of 2.04 and a confidence interval of 1.08 to 3.84. Adjustment for the more granular National Comprehensive Cancer Network version of the index yielded a nearly identical result: hazard ratio 1.96, confidence interval 1.05 to 3.69. However, the classification was not independently associated with overall survival, and the authors are careful to frame these survival findings as exploratory rather than practice-changing.

The implications, if validated prospectively, could reshape the staging pathway for thousands of patients each year. Diffuse large B-cell lymphoma is typically treated with the R-CHOP regimen — rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone — and accurate staging determines both the intensity of treatment and the radiation fields in some approaches. A reliable noninvasive alternative to marrow biopsy would spare patients a painful procedure, reduce healthcare costs, and accelerate the time from diagnosis to treatment. The liver-referenced approach requires no additional scanning, no new tracers, and no specialized software — just a disciplined visual comparison that any trained nuclear medicine physician can perform on images already acquired as standard of care.

The authors are appropriately measured in their conclusions. They acknowledge that BMB positivity did occur in some Both Low patients, that the study was retrospective and single-centre, and that the survival associations were secondary and exploratory. They explicitly call for prospective external validation before the classification is used clinically. But the core finding stands on its own weight: by reading two organs against one internal reference, a century-old diagnostic dilemma gets a modern, image-based answer that is 96 percent reliable when it says the marrow is clear. For a disease that afflicts tens of thousands of people annually, that is not a small refinement — it is a potential reordering of the very first steps of cancer care.

Subject of Research: Diagnostic performance of integrated bone marrow and splenic FDG PET/CT uptake for predicting bone marrow biopsy positivity in diffuse large B-cell lymphoma

Article Title: Integrated bone marrow and splenic [18F]FDG PET/CT uptake for predicting bone marrow biopsy positivity in diffuse large B-cell lymphoma — a retrospective single-centre study

Article References: Byun, S. J., Hwang, Y., Kim, H. W., & Choi, B. (2026). Integrated bone marrow and splenic [18F]FDG PET/CT uptake for predicting bone marrow biopsy positivity in diffuse large B-cell lymphoma — a retrospective single-centre study. BMC Medical Imaging. https://doi.org/10.1186/s12880-026-02761-x

Image Credits: AI Generated

DOI: 10.1186/s12880-026-02761-x

Keywords: diffuse large B-cell lymphoma, FDG PET/CT, bone marrow biopsy, splenic uptake, liver-referenced classification, negative predictive value, inter-reader agreement, lymphoma staging, nuclear medicine, progression-free survival, International Prognostic Index, diagnostic imaging

The material at the heart of the work is room-temperature-vulcanizing silicone, designated RTV-2, a two-part elastomer that cures into a soft, stable, and radiation-tolerant matrix. On its own, silicone is a poor X-ray absorber at the low photon energies used in diagnostic imaging. The researchers changed that by dispersing nanoparticles of bismuth trioxide — Bi2O3 — into the polymer at weight fractions ranging from zero to 60 percent. Bismuth is a heavy element with a high atomic number, which makes it exceptionally efficient at interacting with X-ray photons in the tens of kiloelectronvolt range typical of medical imaging. Crucially, the team avoided lead, sidestepping the toxicity and disposal problems that shadow conventional high-Z materials in radiation applications.

Fabrication relied on solution casting, a technique in which the nanoparticles are dispersed in a solvent, mixed into the silicone precursors, and then allowed to cure into sheets. The concentration of Bi2O3 proved to be the tuning knob for sensitivity: as the loading increased, the photocurrent generated under X-ray illumination rose steadily, reaching roughly 1.66 nanoamperes at the highest loading of 60 weight percent, compared with about 0.56 nanoamperes for pure silicone. That corresponds to a threefold enhancement, a significant jump for a passive polymer system operated at room temperature without any photoconductive gain engineering.

Getting nanoparticles to distribute evenly inside a viscous polymer is notoriously difficult, because particles tend to clump into aggregates that create weak points and inhomogeneous response. The researchers therefore subjected their composites to a battery of structural and morphological checks. X-ray diffraction confirmed that the bismuth oxide retained its monoclinic crystal structure inside the silicone, while scanning electron microscopy and energy-dispersive X-ray spectroscopy with elemental mapping showed the nanorods dispersed uniformly through the amorphous elastomer matrix. Fourier-transform infrared and Raman spectroscopy verified that the chemical bonds of the silicone were undisturbed by the filler, and thermogravimetric analysis demonstrated that the composites remain thermally stable well beyond the temperatures encountered in clinical settings.

The dosimetric testing was carried out with a COMET MXR 320/26 X-ray tube operating at dose rates between 2.8 and 12 milligray per minute, the range relevant to diagnostic exposures. Current-voltage measurements taken at 4.8 milligray per minute revealed a highly linear response across applied voltages from minus 400 to plus 400 volts, which simplifies calibration enormously: a linear detector means the measured signal can be translated directly into dose without complex correction algorithms. At the maximum bias of 400 volts, the devices achieved a signal-to-noise ratio of approximately 1900, meaning the radiation-induced current stands far above the random electrical noise floor — a key figure of merit for detecting the very small signals associated with low-dose imaging.

Repeatability is where many candidate detector materials stumble. A dosimeter that gives a different answer each time it is exposed is clinically useless, no matter how sensitive. The nanocomposite devices delivered a standard deviation of just 2.3 percent over ten consecutive irradiation cycles, indicating that the material’s response is stable across repeated use rather than drifting or fatiguing as charges become trapped in the polymer network. For a flexible organic-inorganic hybrid operating without cooling or annealing steps between measurements, that level of consistency is notable.

To benchmark their results, the authors compared the normalized sensitivity of their detectors — photocurrent per unit dose rate — with commercial metal-oxide-semiconductor field-effect transistor dosimeters, which typically register around 0.1 to 1 nanoampere per milligray. The silicone-bismuth oxide composites achieved roughly 0.35 nanoamperes per milligray per minute, equivalent to about 878 nanocoulombs per milligray per cubic centimeter when normalized by volume, placing them competitively among reported Bi2O3-polymer systems and commercial devices. The comparison matters because MOSFET dosimeters, while well established, accumulate permanent damage with each readout and have finite lifetimes, whereas the nanocomposite response is a transient photocurrent that resets with each exposure.

The physical mechanism underlying the signal is worth unpacking. When diagnostic X-ray photons strike the bismuth oxide nanoparticles, their high atomic number promotes photoelectric absorption, ejecting energetic electrons that can travel into the surrounding silicone matrix. Under an applied electric field, these liberated charge carriers drift toward the electrodes, producing the measured photocurrent. The silicone acts both as an insulating host that prevents dark current from swamping the signal and as a flexible structural scaffold, so the detector can be conformed to curved surfaces — a phantom, a piece of imaging equipment, or potentially a patient — without losing function.

The appeal of a lead-free, real-time, flexible dosimeter extends beyond radiology departments. Quality assurance of imaging equipment, occupational monitoring of staff, and verification of dose delivery in interventional procedures where fluoroscopic exposure can be prolonged all stand to benefit from a detector that reads out continuously, tolerates bending, and contains no toxic heavy metals. The nanocomposite approach also suggests a broader design principle: pairing low-density polymers with high-Z nanoparticles to engineer radiation sensitivity without sacrificing mechanical workability.

The authors are careful to note that this is not yet a bedside technology. Their study demonstrates sensitivity, linearity, repeatability, and an impressive signal-to-noise ratio under laboratory conditions, but long-term stability and mechanical durability remain to be established before the composites could be certified for clinical use. Silicone can age, nanoparticles can migrate, and any detector intended to safeguard patient health must survive years of sterilization, handling, and storage without its calibration drifting. Still, the trajectory is clear: a threefold sensitivity gain from simply tuning nanoparticle loading, achieved in a material that costs little to produce and cures at room temperature, offers a credible route toward dosimeters that are as flexible and disposable as the medical devices they accompany. As diagnostic imaging continues to expand worldwide, and with it the imperative to track every milligray, this silicone-bismuth nanocomposite suggests that the next generation of radiation dosimeters may look less like instruments and more like the soft materials of the body they protect.

Subject of Research: Real-time X-ray dosimetry using bismuth oxide nanoparticle-loaded silicone nanocomposites for diagnostic radiation

Article Title: Investigation of the dosimetric characteristics of real-time silicone/Bi2O3 nanocomposites for the diagnostic level X-rays

Article References: Keyvani, F., Gholamzadeh, L., Malekie, S., & Kashian, S. (2026). Investigation of the dosimetric characteristics of real-time silicone/Bi2O3 nanocomposites for the diagnostic level X-rays. Scientific Reports. https://doi.org/10.1038/s41598-026-76522-9

Image Credits: AI Generated

DOI: 10.1038/s41598-026-76522-9

Keywords: X-ray dosimetry, bismuth oxide nanoparticles, silicone nanocomposite, real-time radiation detector, diagnostic imaging, lead-free materials, photocurrent, signal-to-noise ratio, solution casting, radiation protection, nanocomposites, medical physics

The axillary lymph nodes, located in the armpit, are typically the first destination for breast cancer cells leaving the primary tumor. Whether or not these nodes contain metastatic disease is one of the most powerful prognostic indicators in breast cancer and directly influences surgical planning, including whether a patient undergoes sentinel lymph node biopsy or a more extensive axillary dissection. Current assessment relies on a combination of physical examination, ultrasound, and pathological evaluation of surgically removed nodes, each of which carries limitations. Imaging-based assessment has long struggled to distinguish metastatic from reactive nodes, since enlarged nodes can be benign and normal-sized nodes can harbor microscopic disease.

Ultrafast dynamic contrast-enhanced MRI addresses this problem by dramatically increasing the temporal resolution of the imaging sequence. In conventional breast MRI, the scanner acquires images over several minutes after injection of a gadolinium-based contrast agent, capturing how tumors take up and wash out contrast. Ultrafast protocols compress the earliest phase of this process into a rapid series of acquisitions lasting only seconds each, allowing radiologists to watch the very first moments of contrast arrival. Because malignant tumors grow new, leaky, and disorganized blood vessels—a process called angiogenesis—their enhancement kinetics differ measurably from those of healthy tissue. The ultrafast approach captures tumor neovascularization, microcirculatory changes, and increased vascular permeability at a stage that conventional sequences simply cannot resolve.

The study enrolled 173 consecutive female participants suspected of having a breast mass, recruited between September 2022 and February 2023, with clinical and immunohistochemical information collected for all subjects. MRI data were collected prospectively and analyzed retrospectively. Ultimately, 114 patients formed the analysis groups: 64 with axillary lymph node metastasis and 50 without. The researchers compared morphological features of the lymph nodes, such as their short and long diameters and the presence of a fatty hilum, with dynamic parameters derived from the ultrafast sequence, including maximum slope and time-to-enhancement.

The results were striking. Among tumor types, invasive carcinoma was significantly associated with axillary lymph node metastasis. For the lymph node measurements themselves, short diameter, long diameter, hilum status, maximum slope, and time-to-enhancement all differed significantly between the metastatic and non-metastatic groups, with p values below 0.001. This means that nodes destined to be positive for metastasis were not only larger and more likely to have lost their normal fatty hilum—the traditional ultrasound and MRI signs of involvement—but also enhanced differently on the ultrafast sequence, lighting up faster and more intensely than their benign counterparts.

Multivariate analysis, which statistically separates the contribution of each factor while accounting for the others, identified three independent predictors of nodal metastasis. Short diameter carried an odds ratio of 5.705, meaning that each increase in this measure multiplied the odds of metastasis more than fivefold. Maximum slope was the strongest predictor, with an odds ratio of 9.584, while time-to-enhancement was protective in direction, with an odds ratio of 0.201, reflecting that nodes that enhanced more slowly were less likely to be metastatic. These findings make physiological sense: a metastatic node replaced by tumor tissue develops the same chaotic, hyperpermeable vasculature as the primary cancer, producing rapid, steep contrast uptake that the ultrafast sequence records in real time.

Perhaps most importantly, the researchers found that combining the parameters outperformed any single measure. The combined model achieved an area under the receiver operating characteristic curve of 0.916, significantly better than time-to-enhancement, maximum slope, or short diameter alone. An AUC of 0.916 indicates excellent discriminatory power—well above the 0.8 threshold generally considered good and approaching the 0.9 range regarded as excellent. The team used the Youden index to determine optimal diagnostic thresholds and applied the DeLong test to confirm that the combined model’s advantage over individual parameters was statistically significant rather than a chance finding.

The clinical implications could be substantial. Sentinel lymph node biopsy, while far less invasive than full axillary dissection, still carries risks of lymphedema, nerve injury, and seroma formation, and requires surgery to obtain its answer. A reliable preoperative imaging biomarker of nodal status could help stratify patients, identify those who might safely avoid more extensive procedures, and inform neoadjuvant treatment decisions before the operating room. The authors note that the ultrafast kinetic parameters showed great clinical value not only for diagnosis but also for screening, treatment planning, and prognosis evaluation in breast cancer. Because the sequence adds only seconds to a standard breast MRI protocol, it could be integrated into existing workflows without meaningful increases in scan time or cost.

The study also has limitations worth noting. The analysis involved 114 evaluable patients from a single institution in Hunan, China, and the authors describe the work as a retrospective analysis of prospectively collected data. The study was approved by the Ethics Committee of the First Affiliated Hospital of University of South China and registered under ChiCTR2200065443, with informed consent requirements waived for anonymized clinical data. Validation in larger, multicenter cohorts will be needed before the combined model can be adopted as a standard of care, and the technology requires MRI scanners and software capable of ultrafast acquisition, which are not universally available. The research was supported by the Science and Technology Program of Hunan Province and related provincial and hospital funding programs, and the authors declare no competing interests, although two co-authors are affiliated with Siemens Healthineers, the manufacturer whose MR platforms commonly support ultrafast sequences.

Nevertheless, the study adds to a growing body of evidence that the richest diagnostic information in MRI lies not in static pictures but in the physics of how contrast moves through living tissue. By capturing the first seconds of that movement, ultrafast dynamic contrast-enhanced MRI turns a routine staging question—has the cancer reached the lymph nodes?—into a measurable kinetic signature. If future validation confirms these results, the seconds immediately after contrast injection could become one of the most informative moments in breast cancer imaging, offering patients a noninvasive answer to a question that today still requires a scalpel.

Subject of Research: Ultrafast dynamic contrast-enhanced MRI for detecting axillary lymph node metastases in invasive breast cancer

Article Title: Prospective evaluation of Ultrafast Dynamic Contrast-Enhanced MRI for axillary lymph node metastases in invasive breast cancer

Article References: Yan, P., Zeng, Y., Song, W., Zhang, H., Grimm, R., He, L., Liu, W., & Zhou, H. (2026). Prospective evaluation of Ultrafast Dynamic Contrast-Enhanced MRI for axillary lymph node metastases in invasive breast cancer. BMC Medical Imaging. https://doi.org/10.1186/s12880-026-02712-6

Image Credits: AI Generated

DOI: 10.1186/s12880-026-02712-6

Keywords: breast cancer, ultrafast DCE-MRI, axillary lymph node metastasis, MRI kinetics, time-to-enhancement, maximum slope, cancer imaging, radiology, sentinel lymph node, tumor angiogenesis, ROC analysis, diagnostic imaging

Researchers at Soonchunhyang University Cheonan Hospital in South Korea evaluated the diagnostic performance of single-photon emission computed tomography combined with computed tomography, SPECT/CT, using technetium-99m-labeled red blood cells and a full-ring 360-degree cadmium-zinc-telluride, or CZT, camera. The retrospective analysis covered 65 patients who presented with overt gastrointestinal bleeding between April 2021 and December 2024 and whose initial multiphasic MDCT scans showed no evidence of active extravasation. The findings indicate that this radionuclide approach can detect bleeding sites that conventional cross-sectional imaging misses, with particularly strong results in the small bowel and at surgical anastomosis sites.

The technology behind the study represents a meaningful departure from traditional gamma cameras. Conventional scintigraphy relies on sodium iodide crystals coupled to photomultiplier tubes, which convert gamma photons emitted by the radiotracer into electrical signals. CZT detectors, by contrast, directly convert gamma photons into electron-hole pairs within the semiconductor crystal itself. This direct conversion yields superior energy resolution and spatial resolution, allowing the camera to distinguish true photon signals from scatter more effectively. The full-ring 360-degree configuration also means the detectors completely surround the patient, enabling simultaneous acquisition from all angles rather than the stepwise rotation required by older systems, which shortens acquisition times and improves count statistics.

The imaging protocol in the study followed a two-stage design. Patients first underwent dynamic planar imaging with a dual-head gamma camera, capturing sequential frames that could reveal the moment radiolabeled blood escaped from a vessel into the bowel lumen. This was followed by delayed static SPECT/CT acquisition using the CZT camera, which fused functional information about tracer distribution with anatomical detail from the CT component. The fusion is critical: while planar images can show that bleeding is occurring somewhere in the abdomen, SPECT/CT localizes the extravasation to a specific bowel segment, which is what surgeons and endoscopists actually need.

Technetium-99m-labeled red blood cells work on a simple but elegant principle. A sample of the patient’s own red blood cells is labeled with the gamma-emitting radionuclide technetium-99m and then reinjected into the bloodstream. Because the labeled cells remain within the vascular compartment, any accumulation of signal outside blood vessels indicates active hemorrhage. Unlike iodinated contrast used in CT angiography, which requires a sufficiently rapid bleeding rate at the exact moment of scanning, labeled red blood cells circulate for hours, allowing intermittent or slow bleeding to be captured over an extended window. This is precisely the scenario in which MDCT fails most often.

The results were striking. Of the 65 enrolled patients, 49, or 75.4 percent, were ultimately diagnosed with a gastrointestinal bleeding focus through definitive clinical workup. Against this reference standard, technetium-99m-labeled red blood cell SPECT/CT achieved a sensitivity of 73.5 percent, a specificity of 93.8 percent, a positive predictive value of 97.3 percent, a negative predictive value of 53.6 percent, and an overall accuracy of 78.5 percent. The high positive predictive value is particularly noteworthy: when the scan did show a bleeding site, it was almost always correct, making it a powerful tool for directing targeted interventions.

The performance in specific clinical scenarios was even more impressive. The technique accurately identified bleeding in 21 of 26 patients, or 80.8 percent, who were diagnosed with small bowel bleeding. The small bowel has long been the most challenging region for bleeding localization because its length, mobility, and overlapping loops confound both endoscopy and conventional imaging. Push enteroscopy and capsule endoscopy can visualize the mucosa but offer limited therapeutic reach, and CT often cannot distinguish bleeding within small bowel loops from adjacent structures. A nuclear medicine scan that reliably flags small bowel hemorrhage fills a genuine clinical gap.

Equally remarkable was the detection of bleeding from surgical anastomosis sites. All five patients in the cohort who bled from the connection point of a prior surgical procedure were correctly identified by the SPECT/CT scan, a 100 percent detection rate. Anastomotic bleeding is a feared complication after gastrointestinal surgery, and localizing it can be difficult because postoperative anatomy distorts normal landmarks and inflammation can mimic extravasation on CT. The functional nature of the red blood cell scan, which depends on physiology rather than anatomy, appears to cut through this ambiguity.

The relatively low negative predictive value of 53.6 percent deserves careful interpretation. A negative SPECT/CT scan does not reliably exclude ongoing bleeding, likely because hemorrhage may be truly intermittent, may have temporarily stopped, or may occur at a rate too slow to produce detectable extravasation even over the extended imaging window. Clinicians should therefore treat a negative scan as inconclusive rather than reassuring, and continue to pursue alternative diagnostic pathways if the clinical picture suggests active hemorrhage. Conversely, the exceptional specificity and positive predictive value mean that a positive scan can be acted upon with confidence.

The study’s authors conclude that in patients with overt gastrointestinal bleeding and negative MDCT findings, technetium-99m-labeled red blood cell SPECT/CT could be helpful for detecting bleeding sites, particularly in cases with suspected small bowel bleeding or bleeding from an anastomosis site. As CZT detector technology continues to mature and spread through nuclear medicine departments worldwide, the combination of faster acquisition, better resolution, and fused functional-anatomical localization may reshape the diagnostic algorithm for one of medicine’s most urgent and elusive emergencies. For patients bleeding from a source that no CT can see, this full-ring camera may finally provide the answer.

Subject of Research: Diagnostic performance of technetium-99m-labeled red blood cell SPECT/CT with a 360-degree CZT camera in patients with overt gastrointestinal bleeding and negative multidetector CT findings.

Article Title: Diagnostic performance of 99mTc-labeled red blood cell SPECT/CT using a 360º CZT camera in patients with overt gastrointestinal bleeding and negative findings on multidetector CT

Article References: Yoo, I. D., Lee, S. M., Hong, S.-P., Kim, J. E., & Lee, J. W. (2026). Diagnostic performance of 99mTc-labeled red blood cell SPECT/CT using a 360º CZT camera in patients with overt gastrointestinal bleeding and negative findings on multidetector CT. BMC Medical Imaging. https://doi.org/10.1186/s12880-026-02737-x

Image Credits: AI Generated

DOI: 10.1186/s12880-026-02737-x

Keywords: gastrointestinal bleeding, SPECT/CT, CZT camera, technetium-99m, red blood cell scintigraphy, multidetector CT, small bowel bleeding, nuclear medicine, diagnostic imaging, anastomotic bleeding, radionuclide imaging, hemorrhage detection