American journal of nuclear medicine and molecular imaging最新文献

The most prevalent cause of emergency abdominal surgery is acute appendicitis. Ultrasonography is safe and widely available, although it's operator-dependent and difficult for people with massive bodies. Computed tomography (CT) scans are more accurate than ultrasonography, with a 93 to 98% accuracy rate. The goal of this investigation is to evaluate the diagnostic value of ultrasonography and CT scanning for acute appendicitis. This is a cross-sectional study that was performed on 231 patients with suspected with acute appendicitis. The Alvarado score was initially used to diagnose acute appendicitis. A radiologist performed abdominal ultrasonography on all patients. If the results of the ultrasonography were negative or unclear, a CT scan was performed using oral contrast. Finally, all ultrasonography and CT scan data were reevaluated by an experienced radiologist and compared to the patient's final diagnosis in the case of surgery and pathology results. Comparisons between the two groups were performed. The sensitivity, specificity, and positive and negative predictive value of ultrasonography according to pathology results in patients with low clinical suspicion were 74.9%, 63.4%, 94.3%, and 67.6%, respectively. The sensitivity, specificity, positive and negative predictive value of CT scans based on pathology results were 87.9%, 81.8%, 94.7%, and 79.3%, respectively, in patients with low clinical suspicion. The CT scan results in female patients suspected of appendicitis were completely consistent with the pathology results. The CT scan demonstrated greater specificity and sensitivity in diagnosing acute appendicitis compared to abdominal ultrasonography.

The PI3K/Akt/mTOR pathway is frequently dysregulated in cancer due to its central role in cell growth, survival, and proliferation. Overactivation of the PI3K/Akt/mTOR pathway may occur through varying mechanisms including mutations, gene amplification, and upstream signaling events, ultimately resulting in cancer. Therefore, PI3K/Akt/mTOR pathway has emerged as an attractive target for cancer therapy and imaging. A promising approach to inhibit this pathway involves a simultaneous inhibition of both PI3K and mTOR using a dual inhibitor. Recently, a potent dual PI3K/mTOR inhibitor, 2,4-difluoro-N-(2-methoxy-5-(3-(5-(2-(4-methylpiperazin-1-yl)ethyl)-1,3,4-oxadiazol-2-yl)imidazo[1,2-a]pyridin-6-yl)pyridin-3-yl)benzenesulfonamide (7), was discovered and demonstrated excellent kinase selectivity IC₅₀ (PI3K/mTOR) = 0.20/21 nM; good cellular growth inhibition IC₅₀ (HCT-116 cell) = 10 nM, modest plasma clearance, and acceptable oral bioavailability. Expanding on this discovery, here we present the synthesis of the carbon-11 labeled imidazo[1,2-a]pyridine derivative 2,4-difluoro-N-(2-methoxy-5-(3-(5-(2-(4-[¹¹C]methylpiperazin-1-yl)ethyl)-1,3,4-oxadiazol-2-yl)imidazo[1,2-a]pyridin-6-yl)pyridin-3-yl)benzenesulfonamide (N-[¹¹C]7) as a new potential radiotracer for the biomedical imaging technique positron emission tomography (PET) imaging of PI3K/mTOR in cancer. The reference standard 7 and its N-demethylated precursor, 2,4-difluoro-N-(2-methoxy-5-(3-(5-(2-(piperazin-1-yl)ethyl)-1,3,4-oxadiazol-2-yl)imidazo[1,2-a]pyridin-6-yl)pyridin-3-yl)benzenesulfonamide (11), were synthesized in 7 and 8 steps with 10% and 7% overall chemical yield, respectively. N-[¹¹C]7 was prepared from 11 using [¹¹C]methyl triflate ([¹¹C]CH₃OTf) through N-¹¹C-methylation and isolated by high-performance liquid chromatography (HPLC) and solid-phase extraction (SPE) formulation in 40-50% radiochemical yield decay corrected to end of bombardment (EOB) based on [¹¹C]CO₂. The radiochemical purity was > 99% and the molar activity (A_m) at EOB was in the range of 296-555 GBq/µmol (n = 5).

Erdheim-Chester disease (ECD) is a rare and clinically heterogeneous non-Langerhans cell histiocytosis, and its diagnosis relies on established clinical, radiologic, histopathological criteria. ECD can be evaluated by whole-body preoperative imaging methods. Although ¹⁸F-FDG PET/CT shows negative findings in some splenic benign or borderline lesions, such as splenic inflammatory myofibroblastic tumors and hemangioendotheliomas, it can provide value in differentiating some malignant diseases, such as hemangiosarcoma and metastases. Here, we report the CT, MRI, and ¹⁸F-FDG PET/CT imaging performance of an ECD patient who presented with only spleen involvement. Even though some clinical and radiological descriptions can be found in the literature, ECD reports with only splenic involvement mimicking splenic hemangioma as the first presentation are rare, to the best of our knowledge. Histopathology and molecular analysis of this case confirmed the diagnosis of ECD. Clinicians should pay attention to the possibility of ECD occurrence in the spleen, while negative findings on ¹⁸F-FDG PET/CT of the spleen indicated a low risk for high-grade malignant splenic tumors and metastases.

Molecular imaging can dynamically and quantitatively record the biochemical changes in a systemic view. In this research, SARS-CoV-2 pseudovirus was intramuscularly injected to simulate the vaccination with inactivated virus. New Zealand white rabbits were evaluated with ¹⁸F-FDG PET for inflammation and ⁶⁸Ga-cyc-DX600 PET for ACE2 fluctuation, which were performed before and at 3, 7 and 14 days post injection (d P.I.); furthermore, one rabbit was vaccinated with two cycles with interval of 14 days for a longer period evaluation. Different with the vaccination-induced inflammatory response that was random and individual, ACE2 regulation was systemic and organ-specific: the liver and spleen were of a moderate decrease post injection but rebound at 14 d P.I., while there were a downward trend in heart, testis and bone marrow; besides, similar pattern of ACE2 regulation were recorded after the second injection with a relatively greater volatility. In conclusion, ACE2 PET gave a more comprehensive view on host response post vaccination, hold substantial promise in continuous monitoring of coronavirus vaccine administration and effectiveness.

Background: One of the most useful tools for identifying sleep disturbances is neuroimaging, especially magnetic resonance imaging (MRI). This review research was to look at the role of MRI findings in movement disorders and sleep disturbances.

Methods: This review collects all MRI data on movement disorders and sleep disruptions. Between 2000 and 2022, PubMed and Google Scholar were utilized to find original English publications and reviews. According to the inclusion and exclusion criteria, around 100 publications were included. We only looked at research that explored MRI modality together with movement problems, sleep disorders, and brain area involvement. Most of the information focuses on movement irregularities and sleep interruptions.

Results: Movement disorders such as Parkinson's disease (PD), Huntington's disease (HD), neuromuscular diseases, rapid eye movement (REM) sleep behavior movement disorder (RBD), cerebellar movement disorders, and brainstem movement disorders are assessed using MRI-based neuroimaging techniques. Some of the brain areas were associated with disorders in movement abnormalities and related sleep disturbances. This review found that many people with mobility disorders also have sleep problems. Some brain areas' malfunctions may cause motor and sleep issues.

Conclusion: Neuroimaging helps us understand the sleep difficulties associated with movement disorders by examining the structural and functional implications of movement disorders and sleep disturbances.

One novel option for treating metastatic castration resistant prostate cancer is radionuclide therapy targeting prostate-specific membrane antigen (PSMA), e.g. [¹⁷⁷Lu]Lu-PSMA-617. Overexpression of HER2 has been found in 80% of metastatic cases of prostate cancer. Previous research showed that HER2 is elevated post irradiation in PC-3 prostate cancer cells. Co-treating with anti-HER2 antibody Trastuzumab gave less proliferation of irradiated tumor cells in vitro, and when using radionuclide therapy, also in vivo. The aim of this study is to determine whether the same holds true in PSMA-expressing PC-3 PIP cells using [¹⁷⁷Lu]Lu-PSMA-617 radionuclide therapy. PC-3 PIP and 22Rv1 prostate cancer cells were tested in vitro, treated with 6 Gy of x-rays with or without Trastuzumab incubation. We measured uptake of HER2-targeting affibody [⁶⁸Ga]Ga-ABY-025 and cell survival, e.g. using the WST-1 assay. Three groups (n=10 each) of male nude Balb/c mice were inoculated with PC-3 PIP xenograft tumors and treated with just [¹⁷⁷Lu]Lu-PSMA-617 (20 MBq), [¹⁷⁷Lu]Lu-PSMA-617 (20 MBq) and Trastuzumab (4 × 5 mg/kg), or left untreated. Tumor sizes and animal survival was observed. In vitro, x-ray irradiation did reduce survival in 22Rv1 but not PC-3 PIP cells, and there was no significant effect of Trastuzumab treatment. Cells expressed HER2 but not significantly elevated post irradiation. In vivo, mice co-treated with Trastuzumab had significantly longer survival than untreated mice, but not than only [¹⁷⁷Lu]Lu-PSMA-617. Staining of tumor sections showed similar HER2 and PSMA expression across groups. In conclusion, these results give no support for any benefit from co-treatment with anti-HER2 antibody for PSMA-targeted radioligand therapy.

Background: Deep learning (DL) algorithms have shown promise in identifying and quantifying lesions in PET/CT. However, the accuracy and generalizability of these algorithms relies on large, diverse datasets which are time and labor intensive to curate. Modern PET/CT scanners may acquire data in list mode, allowing for multiple reconstructions of the same datasets with different parameters and imaging times. These reconstructions may provide a wide range of image characteristics to increase the size and diversity of datasets. Training algorithms with shorter imaging times and higher noise properties requires that lesions remain detectable. The purpose of this study is to model and predict the contrast-to-noise ratio (CNR) for shorter imaging times based on CNR from longer duration, lower noise images for ⁶⁸Ga DOTATATE PET hepatic lesions and identify a threshold above which lesions remain detectable.

Methods: ⁶⁸Ga DOTATATE subjects (n=20) with hepatic lesions were divided into two subgroups. The "Model" group (n=4 subjects; n=9 lesions; n=36 datapoints) was used to identify the relationship between CNR and imaging time. The "Test" group (n=16 subjects; n=44 lesions; n=176 datapoints) was used to evaluate the prediction provided by the model.

Results: CNR plotted as a function of imaging time for a subset of identified subjects was very well fit with a quadratic model. For the remaining subjects, the measured CNR showed a very high linear correlation with the predicted CNR for these lesions (R² > 0.97) for all imaging durations. From the model, a threshold CNR=6.9 at 5-minutes predicted CNR > 5 at 2-minutes. Visual inspection of lesions in 2-minute images with CNR above the threshold in 5-minute images were assessed and rated as a 4 or 5 (probably positive or definitely positive) confirming 100% lesion detectability on the shorter 2-minute PET images.

Conclusions: CNR for shorter DOTATATE PET imaging times may be accurately predicted using list mode reconstructions of longer acquisitions. A threshold CNR may be applied to longer duration images to ensure lesion detectability of shorter duration reconstructions. This method can aid in the selection of lesions to include in novel data augmentation techniques for deep learning.

Claudin 18.2 (CLDN18.2) is an emerging target for the treatment of CLDN18.2-expressing cancers such as gastric and pancreatic cancers. Cell and antibody therapies targeting CLDN18.2 are under intensive clinical trials. In this setting, how to efficiently and specifically detect CLDN18.2 expression before and after the therapies is a clinical challenge. In recent years, molecular imaging with radiolabeled antibodies or antibody fragments have shown promise in noninvasively annotating antigen expression across the body. In this Perspective, we will bring together the most recent progress on CLDN18.2-targeted imaging and therapy of solid tumors.

While Tc-99m MDP bone scan (BS) remains the conventional standard for detection of bone metastasis in prostate cancer, newly FDA-approved imaging with PSMA-based ¹⁸F-DCFPyL PET/CT has shown promise for early detection of metastatic disease. However, a paucity of data remains in the diagnostic accuracy of PSMA PET/CT in detecting bone metastasis compared to BS. This retrospective study included 91 patients who received both BS and PSMA PET/CT within a 3-month interval from August 2021 to February 2022. Separate concurrent primary cancer, interval PSA levels greater than a 2-fold difference (or absolute difference >1 ng/ml) between the two studies were excluded. All abnormal bone lesions on either scan were compared. The findings were verified by pathological findings and/or 6-month clinical follow-up. High concordance (78%) was found between modalities with discordant findings (20/91, 22%) demonstrating more false positives (4/20, 20%) and false negatives (3/20, 15%) on BS compared to PET/CT. Additionally, more bone metastases were detected on PSMA PET/CT (13/20, 65%) with all true positive BS lesions also detected PET/CT. The sensitivity, specificity, PPV and NPV for BS were 89%, 91%, 80%, and 95% respectively; and 100%, 97%, 93%, and 100% for ¹⁸F-DCFPyL PET/CT respectively. Our results demonstrate that ¹⁸F-DCFPyL PET/CT identified more bone metastases while also identifying all bone metastases identified on BS. With the added diagnostic value of detecting primary tumor and soft tissue metastasis, ¹⁸F-DCFPyL PET/CT may render BS unnecessary to investigate bone metastases in patients with prostate cancer.

Uterine adenosarcoma is a rare gynecological malignancy with no specific symptoms, and the optimal management is still inconclusive. Herein we present a case of uterine adenosarcoma in a 38-year-old woman with a good prognosis and review of literatures. The patient presented with abnormal vaginal bleeding with no special medical history. Sonographic scan revealed a heterogeneous echoic mass in the cavity, indicating a polypus or a submucous myoma. The pathology based on the specimen after the hysteroscopic tumor excision suggested diagnosis of uterine adenosarcoma. Subsequently, the patient received pelvic MRI scan before surgery. MRI identified a patchy lesion at the cervix-lower endometrial cavity with low signal in T1WI and a mixed high T2 signal in T2WI, with no sign of metastasis. Then total abdominal hysterectomy with bilateral salpingo-oopherectomy plus pelvic lymph node dissection was performed and 6 cycles of chemotherapy were administered. The patient remains disease-free on follow-up to date, more than 15 months after chemotherapy.