American journal of nuclear medicine and molecular imaging最新文献

Background: Children and young adults have a vast array of electronics at their fingertips. While it can provide endless hours of entertainment and education, we are also seeing a structural consequence. Children are using these devices with their head tilted down with poor posture resulting in increased stress on the skull from attached structures which can lead to a bone spur (exostosis) at the external occipital protuberance (EOP). While typically painless, it can progress to necessitate surgical intervention.

Objectives: The purpose of this study is to understand the prevalence of exostosis at the EOP and how the finding can affect the nuclear medicine bone scan.

Materials and methods: 43 pediatric patients who underwent a whole-body bone scan over a period of 1 year were included in the study (10-19 years old). Images were reviewed by 2 board-certified Nuclear Medicine physicians to assess for uptake midline in the occipital skull. Suspected cases were followed up with all available clinical and radiographic reports and images.

Results: Bone scan demonstrated an occipital focus of uptake in 7 (16%) of the 43 patients (5 males and 2 females with a mean age of 15 years; range 10-19). Of these, 5/7 (71%) were confirmed by additional imaging.

Conclusion: The rapidly advancing technology is leading to increased screen time in children and young adults. Our study shows that 16% of the pediatric population imaged at our facility between the ages of 10-19 years have signs of exostosis at the EOP. It is particularly important for clinicians to be aware of this entity when reading bone scans to avoid false positive interpretations.

Waldenstrom macroglobulinemia (WM) is a rare inert B lymphocyte lymphoma and the role of FDG PET/CT imaging in WM has not been well established. This study aimed to evaluate the metabolic status of WM by ¹⁸F-FDG PET/CT imaging. We retrospectively analyzed 20 patients who underwent pretherapy ¹⁸F-FDG PET-CT scan. All patients were diagnosed by bone marrow aspiration, laboratory examination and clinical symptoms. Bone marrow involvement was identified with ¹⁸F-FDG PET/CT imaging in 16 of 20, and the mean SUVmax of bone marrow was 4.06±0.85, Lymph nodes were involved in 8 of 20 patients, and the mean SUVmax of Lymph nodes was 4.07±1.27. Liver and spleen were involved in one case respectively, with SUVmax being 3.6 and 3.3. 1 case of extramedullary infiltration and 1 case of lymphomatous transformation. ¹⁸F-FDG PET/CT imaging not only could reveal the metabolic status of lymph nodes, liver, spleen and bone marrow in WM patients, but also evaluate the status of tumor burden which helps to formulate personalized treatment plans.

Background: The aim of this study was to determine the read-out capabilities of the novel C-X-C motif chemokine receptor 4 (CXCR4)-targeting radiotracer [⁶⁸Ga]Ga-PentixaFor compared to the reference radiotracer [¹⁸F]FDG in untreated individuals with head and neck squamous cell carcinoma (HNSCC).

Material and methods: 12 patients with histologically confirmed HNSCC were scheduled for [¹⁸F]FDG and [⁶⁸Ga]Ga-PentixaFor PET/CT. Maximum standardized uptake values (SUV_max) and target-to-background ratios (TBR) were applied with vena cava superior serving as reference. In addition, we compared [⁶⁸Ga]Ga-PentixaFor-PET findings with immunohistochemical (IHC) results of CXCR4 expression.

Results: On visual assessment, [¹⁸F]FDG identified more sites of disease, with increased detection rates for both the primary tumor ([¹⁸F]FDG, 12/12 [100%] vs. [⁶⁸Ga]Ga-PentixaFor, 10/12 [83%]) and LN metastases ([¹⁸F]FDG, 9/12 [75%] vs. [⁶⁸Ga]Ga-PentixaFor, 8/12 [67%]). Indicative for improved image contrast using [¹⁸F]FDG, quantification showed a higher TBR for the latter radiotracer, when compared to [⁶⁸Ga]Ga-PentixaFor for all lesions ([¹⁸F]FDG, 11.7 ± 8.5 vs. [⁶⁸Ga]Ga-PentixaFor, 4.3 ± 1.3; P=0.03), primary tumors ([¹⁸F]FDG, 13.6 ± 8.7 vs. [⁶⁸Ga]Ga-PentixaFor, 4.4 ± 1.4; P<0.01), and LN lesions ([¹⁸F]FDG, 9.3 ± 10.6 vs. [⁶⁸Ga]Ga-PentixaFor, 4.7 ± 1.5; P=0.3). IHC showed variable CXCR4 expression in the primary and LN, along with no associations between ex-vivo CXCR4 upregulation and [⁶⁸Ga]Ga-PentixaFor-based TBR (R=0.33, P=0.39) or SUV_max (R=0.44, P=0.2). Of note, IHC also revealed heterogeneous expression of CXCR4 in immune cells in the tumor microenvironment and in germinal centers, indicative for inflammatory reactions.

Conclusions: In HNSCC, [¹⁸F]FDG demonstrated superior diagnostic performance relative to [⁶⁸Ga]Ga-PentixaFor, in particular for assessment of the primary. Based on the IHC analyses, these findings may be explained by CXCR4 upregulation not only by tumor but also by immune cells in the tumor microenvironment.

Radiotracers and medical imaging equipment are the two main keys to molecular imaging. While radiotracers are of great interest to research and industry, medical imaging equipment technology is blossoming everywhere. Total-body PET/CT (TB-PET/CT) has emerged in response to this trend and is rapidly gaining traction in the fields of clinical oncology, cardiovascular medicine, inflammatory/infectious diseases, and pediatric diseases. In addition, the use of a growing number of radiopharmaceuticals in TB-PET/CT systems has shown promising results. Notably, the distinctive features of TB-PET/CT, such as its ultra-long axial field of view (194 cm), ultra-high sensitivity, and capability for low-dose tracer imaging, have enabled enhanced imaging quality while reducing the radiation dose. The envisioned whole-body dynamic imaging, delayed imaging, personalized disease management, and ultrafast acquisition for motion correction, among others, are achieved. This review highlights two key factors affecting molecular imaging, describing the rapid imaging effects of radiotracers allowed at low doses on TB-PET/CT and the improvements offered compared to conventional PET/CT.

A remarkable body of new data establishes that many degenerative brain diseases and some acute injury situations in the brain may be associated with ferroptosis. In recent years, ferroptosis has also attracted great interest in the cancer research community, partly because it is a unique mode of cell death distinct from other forms and thus has great therapeutic potential for brain cancer. Glioblastoma is a highly aggressive and fatal human cancer, accounting for 60% of all primary brain tumors. Despite the development of various pharmacological and surgical modalities, the survival rates of high-grade gliomas have remained poor over the past few decades. Recent evidence has revealed that ferroptosis is involved in tumor initiation, progression, and metastasis, and manipulating ferroptosis could offer a novel strategy for glioma management. Nanoparticles have been exploited as multifunctional platforms that can cross the blood-brain barrier and deliver therapeutic agents to the brain to address the pressing need for accurate visualization of ferroptosis and glioma treatment. To create efficient and durable ferroptosis inducers, many researchers have engineered nanocomposites to induce a more effective ferroptosis for therapy. In this review, we present the mechanism of ferroptosis and outline the current strategies of imaging and nanotherapy of ferroptosis in brain diseases, especially glioma. We aim to provide up-to-date information on ferroptosis and emphasize the potential clinical implications of ferroptosis for glioma diagnosis and treatment. However, regulation of ferroptosis in vivo remains challenging due to a lack of compounds.

The earlier identification of EGFR mutation status in lung adenocarcinoma patients is crucial for treatment decision-making. Radiomics, which involves high-throughput extraction of imaging features from medical images for quantitative analysis, can quantify tumor heterogeneity and assess tumor biology non-invasively. This field has gained attention from researchers in recent years. The aim of this study is to establish a model based on ¹⁸F-FDG PET/CT radiomic features to predict the epidermal growth factor receptor (EGFR) mutation status of lung adenocarcinoma and evaluate its performance. 155 patients with lung adenocarcinoma who underwent ¹⁸F-FDG PET/CT scans and EGFR gene detection before treatment were retrospectively analyzed. The LIFEx packages was used to perform 3D volume of interest (VOI) segmentation manually on DICOM images and extract 128 radiomic features. The Wilcoxon rank sum test and least absolute shrinkage and selection operator (LASSO) regression algorithm were applied to filter the radiomic features and establish models. The performance of the models was evaluated by the receiver operating characteristic (ROC) curve and the area under the curve (AUC). Among the models we have built, the radiomic model based on ¹⁸F-FDG PET/CT has the best prediction performance for EGFR gene mutation status, with an AUC of 0.90 (95% CI 0.84~0.96) in the training set and 0.79 (95% CI 0.64~0.94) in the test set. In conclusion, we have established a radiomics model based on ¹⁸F-FDG PET/CT, which has good predictive performance in identifying EGFR gene mutation status in lung adenocarcinoma patients.

This study aimed to determine the comparability of tumor-uptake indices of ¹⁸F-FDG in positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance imaging (PET/MRI). 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) PET/CT and PET/MRI were performed on 55 patients with confirmed primary malignancies. PET/CT preceded PET/MRI in all examinations. Accumulation of ¹⁸F-FDG in lesions and normal organs (brain, liver) was measured. Maximum and peak standardized uptake values (SUVs; SUV_max and SUV_peak, respectively), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) with margin thresholds of SUV of 50% (MTV_50%; TLG_50%, respectively) were measured as indices for comparison of measurements in tumors. Comparative indices with tumor SUV_max and liver ratio (TLR_max), brain ratio (TBR_max) were calculated. These indices were compared between PET/CT and PET/MRI examinations. The data measured using PET/CT and PET/MRI showed significant correlations for all tumor indices. The correlation was strongest for SUV_peak (r = 0.933), followed by TBR_max (r = 0.929); and the index ratio of (PET/CT)/(PET/MRI) data was close to 1.0 for TLR_max (1.00 ± 0.22) and TBR_max (1.01 ± 0.21), followed by MTV_50% (0.82 ± 0.33) and TLG_50% (1.18 ± 0.45). The values of all indices showed strong correlations between PET/CT and PET/MRI examinations. Among them, TLR_max, TBR_max, MTV_50%, and TLG_50% showed a close value and may be useful for comparison of tumor evaluation between two PET systems.

Objective: The glenohumeral (GH) joint is a classic ball-and-socket joint of the shoulder subject to various pathologies including osteoarthritis (OA). Degenerative changes of the OA evident on traditional imaging are proceeded by molecular changes, which if detected early could enhance disease prevention and treatment. In this study, we use ¹⁸F-FluoroDeoxyGlucose (FDG) and ¹⁸F-sodium-fluoride (NaF)-PET/CT to investigate the effects limb laterality, age, and BMI on the inflammation and bone turnover of the GH shoulder joint.

Methods: FDG and NaF-PET/CT scans of 41 females (mean age of 43.9 ± 14.2 years) and 45 males (mean age of 44.5 ± 13.8 years) were analyzed with a semi-quantitative technique based on predefined region of interest.

Results: There was greater FDG uptake in the left side of the GH joint compared to the right in both females (left: 0.79 ± 0.17, right: 0.71 ± 0.2; P < 0.0001) and males (left: 0.76 ± 0.19, right: 0.57 ± 0.18; P < 0.0001). We also observed a strong positive association between BMI and FDG uptakes in females (left: P < 0.0001, r = 0.71, right: P < 0.0001, r = 0.58) and males (left: P < 0.0001, r = 0.56, right: P < 0.0001, r = 0.64). Association between BMI and NaF uptake were found in males as well (left: P = 0.004, r = 0.42, right: P = 0.02, r = 0.35).

Conclusion: Our study demonstrates the varying effect of limb laterality and BMI on FDG and NaF uptake at the GH joint. Adoption of molecular imaging will require future studies that correlate tracer uptake with relevant medical and illness history as well as degenerative change evident on traditional imaging.

In the last two decades, advancements in positron emission tomography (PET) technology have increased the diagnostic accuracy of patients with large-vessel vasculitis (LVV). Numerous systematic reviews and meta-analyses have been conducted, and patients suspected of having LVV can be diagnosed earlier with 18F-FDG PET. Two subtypes, giant cell arteritis (GCA) and Takayasu arteritis (TA), will progress when their response to corticosteroids and enhanced immunosuppression is inadequate. In the majority of patients, disease activity cannot be monitored solely through laboratory procedures; consequently, glucose metabolism may be a source of potential biomarkers. In this article, we discuss the current state of 18F-FDG PET/CT imaging standards.

Follicular lymphoma (FL) is a subtype of non-Hodgkin lymphoma (NHL) that is typically characterized by a slow-growing course. Duodenal-type follicular lymphoma (D-FL) was recently reclassified as a distinct variant. This subtype exhibits unique clinical and biological characteristics, which set it apart from other forms of FL. We report a case of a 36-year-old male patient with multiple, small, gray polypoid lesions in the descending duodenum which were detected by esophagogastroduodenoscopy. The pathological diagnosis was low-grade D-FL. ¹⁸F-FDG PET/CT was performed for staging and revealed the pancreas and peripheral lymph nodes were involved by FL, with a clinical IV stage. The patient underwent a bone marrow smear cytology, which revealed no bone marrow abnormalities, and excluded bone marrow involvement. He was treated with six cycles of chemotherapy using the R-CHOP regimen and reached complete remission.