American journal of nuclear medicine and molecular imaging最新文献

Large lipid core (extended into arterial lumen) and high density of macrophages (associated with ¹⁸F-fluorodeoxyglucose "¹⁸F-FDG" uptake) in atherosclerotic plaque were shown to be an overt feature of plaque rupture. Nineteen participants were imaged with computed tomography (CT) and positron emission tomography (PET) with ¹⁸F-FDG in a dynamic mode. The mean lumen density in Hounsfield unit (HU) was measured per region of interest (ROI) on CT images and classified as non-calcified and calcified classifications. Calcified group was divided into partially calcified and calcified groups. Metabolic rate of glucose (MRG) was computed per ROI on PET dynamic images using modified 2-tissue compartmental model that is independent of partial volume effect. Data is clustered using Automatic Hierarchical K-means algorithm (AKH) with silhouette-coefficient. Arterial segments of 1180 ROIs for Aorta and iliac arteries were classified as non-calcified and calcified segments and clustered using AHK with respect to the mean of intravascular attenuation (in HU). There was a statistical difference in MRG corresponded to low intravascular attenuation cluster compared to higher intravascular attenuation clusters (P<0.05), but not within higher clusters (P>0.05), for both non-calcified and calcified classes. In partially calcified segments, same pattern was observed as the low intravascular attenuation cluster was accompanied with significant metabolic activity but not for calcified segments. Low intravascular attenuation is associated with high MRG measured on ¹⁸F-FDG PET images, which may reflect the instability of atherosclerotic plaque. Partially calcified plaque is metabolically active compared to calcified plaque.

[This corrects the article on p. 352 in vol. 11, PMID: 34754606.].

Owing to the high tissue contrast, multiparametric MRI (mpMRI) has already been the most widely applied imaging method for prostate cancer. Recently, prostate-specific membrane antigen (PSMA) ligands for nuclear imaging are emerging as a promising modality in prostate cancer, especially since the 2 PET/CT agents (⁶⁸Ga-PSMA-11 and ¹⁸F-DCFPy) approved by U.S. Food and Drug Administration (FDA). However, limited studies have performed the comparison of mpMRI versus recently approved ¹⁸F-DCFPyL PET/CT. In this issue of AJNMMI, Lu et al. compared the performance of ¹⁸F-DCFPyL PET/CT and pelvic mpMRI in intermediate-high risk and biochemical recurrent prostate cancer patients. The results demonstrated the two modalities have a good concordance rate for patient-based analysis, and ¹⁸F-DCFPyL PET/CT has a better diagnostic performance in detecting lymph node metastases and bone metastases for lesion-based analysis. The use of ¹⁸F-DCFPyL PET/CT provides more diagnostic confidence to better assess prostate cancer lesions.

This study aimed to analyze the diagnostic efficacy of ^99mTc-methoxy isobutyl isonitrile (MIBI) single photon emission tomography (SPECT/CT) myocardial perfusion imaging (MPI) and cardiac magnetic resonance imaging (CMR) in children with myocarditis caused by different infection sources and provide an imaging reference basis for clinical diagnosis and treatment. In total, 232 children diagnosed with myocarditis were retrospectively divided into five groups according to the different infection sources: viral infection (group A), bacterial infection (group B), viral combined with bacterial infection (group C), viral combined with mycoplasma infection (group D), and bacterial combined with mycoplasma infection (group E). A chi-square test and ANOVA were used to analyze the difference between SPECT/CT MPI and CMR in the diagnosis of myocarditis in children according to their categorical infection source group, including the impact of the average daily hospital costs (a=0.05). The positive rates of SPECT/CT in groups A and D were higher than those of CMR, and the positive rates of SPECT/CT in groups C and E were lower than those of CMR, with statistically significant differences (P < 0.05). The SPECT/CT ischemic lesions were located in the anterior wall, or the anterior wall combined with other walls of the left ventricle in 69.5% of patients. SPECT/CT MPI had no effect on the average daily hospitalization cost (P > 0.05); however, the average daily hospitalization cost of CMR-negative patients in group D was higher than that of CMR-positive patients, and it was statistically significant in groups C and E (P < 0.05). In groups A and D, the use of ^99mTc-MIBI SPECT/CT MPI was preferred for diagnosing myocarditis. The detection rate of CMR was higher in groups C and E. SPECT/CT MPI findings of ischemic segments were mostly found in the anterior wall. The results of CMR diagnosis affected the average daily hospitalization cost among patients with different infection sources; however, SPECT/CT had no such effect. These findings denote a potential targeted approach to myocarditis diagnosis in pediatric patients based on source of infection.

Antisense imaging uses radionuclide labeled antisense oligonucleotides to hybridize with nucleic acids in vivo, display the expression of target genes, and directly quantify biological processes at the cellular and subcellular levels. The anti-miRNA oligonucleotides (AMOs) are a series of single-stranded DNA oligonucleotides that are widely used in gene imaging and gene therapy. However, due to the negative charge and high molecular weight, the permeability through the membrane of AMOs is generally low so that most AMOs cannot enter the cells. Based on the ^99mTc-labeled AMOs imaging in previous studies, this study developed a novel tetrapeptide Glycine-Alanine-Glycine-Lysine (Gly-Ala-Gly-Lys, GAGK) for one-step labeling AMO with ^99mTc. The labeling conditions were optimized by changing the number of stannous ions, the reaction time, and the temperature, respectively. The labeled products were identified by gel electrophoresis and their serum stability was evaluated. The optimal labeling condition in this study was using 1 mg/mL SnCl₂·2H₂O and heating for 30 min at 100°C. Gel electrophoresis confirmed the verification of successful labeling of ^99mTc-GAGK-AMO. After being incubated with human fresh serum for 12 h, ^99mTc-GAGK-AMO showed good stability and no obvious degradation. Therefore, this labeling method has high labeling efficiency and stable labeling, which provides an effective method for the application of miRNA-targeted imaging.

Here we reported a 59-year-old male who had undergone brain surgery three times and the pathological results showed atypical meningioma (2015, WHO grade I; 2018, WHO grade II; 2019, WHO grade II-III), with multiple pulmonary nodules, which arose during follow-up. A total-body ¹⁸F-FDG PET/CT showed multiple solid nodules with increased ¹⁸F-FDG metabolism (SUVmax = 8.6). The patient underwent a CT-guided lung biopsy and the histopathological study showed positive staining of epithelial membrane antigen (EMA), vimentin (VIM), SSTR2, Ki67 (20%), and negative staining of CK, TTF-1, CD34, SY, PR, P40, respectively. Based on the history and immunohistology results, multiple pulmonary metastases from atypical meningioma were finally diagnosed, since double positive staining of EMA and VIM supported the diagnosis of meningioma and negative staining excluded primary lung cancers. The patient has given up any treatment because of personal reasons. Pulmonary metastasis from meningioma is rare, accurate diagnosis should be based on medical history, imaging characteristics, and histopathological findings.

To meet the increasing demand for PRRT in the treatment of patients with inoperable/disseminated well-differentiated neuroendocrine tumors (NETs) and to guide optimization strategies, adequate and accessible predictive tools that allow to stratify patients who will benefit from treatment from those who will not are becoming indispensable. Previously, we have investigated the role of baseline [⁶⁸Ga]Ga-DOTATOC PET tumor uptake and volumetric parameters and a blood-derived inflammatory biomarker, the inflammation-based index (IBI), for outcome prediction in NET patients treated with [⁹⁰Y]Y-DOTATOC. In this retrospective study in 83 NET patients treated with [¹⁷⁷Lu]Lu-DOTATATE in a routine clinical setting, we aimed to evaluate the generalizability of our previous findings to [¹⁷⁷Lu]Lu-DOTATATE treatment combined with a pre-therapeutic [⁶⁸Ga]Ga-DOTATATE PET. A semi-automatic customized SUV threshold-based approach was used for tumor delineation. The previously identified SUV_mean cut-off of 13.7 for better survival could not be applied to this patient cohort. Instead, a more optimal cut-off could be identified: an SUV_mean lower or equal than 11.2 was associated with worse overall survival (OS) (hazard ratio (HR) 2.28; P = 0.008). Also in line with our previous study, a [⁶⁸Ga]Ga-DOTATATE-avid tumor volume (TV) higher than 672 mL and an elevated baseline IBI were correlated with worse OS (HR 3.13 (P = 0.0001) and HR 2.00 (P = 0.034), respectively). Multivariate analysis confirmed independent associations between OS and baseline IBI (P = 0.032), SUV_mean (P = 0.027) and [⁶⁸Ga]Ga-DOTATATE-avid TV (P = 0.001). Taking baseline IBI, [⁶⁸Ga]Ga-DOTATATE-avid TV and [⁶⁸Ga]Ga-DOTATATE uptake into account may help guide PRRT treatment decisions.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality. Early detection of HCC is important since potentially curative therapies exist in the initial stages of HCC; no curative therapies exist for late-stage HCC. However, the initial detection of HCC remains challenging due to the lack of symptoms during the early stage of the disease. Other methods of screening and detecting HCC, including blood serum tests and conventional imaging methods, remain inadequate due to genetic differences between patients and the high background activity of liver tissues. Thus, there is a need for an accurate imaging agent for the diagnosis, staging, and prognosis of HCC. Glypican-3 (GPC3) is an oncofetal receptor responsible for regulating cell division, growth, and survival. GPC3 is a clinically relevant biomarker for imaging and therapeutics, as its expression is HCC tumor-specific and absent from normal and other pathological liver tissues. The development of novel GPC3-targeting imaging agents has encompassed three classes of biomolecules: peptides, antibodies, and aptamers. These biomolecules serve as constructs for diagnostic imaging (demonstrating potential as positron emission tomography [PET], single-photon emission tomography [SPECT], and optical imaging agents) and HCC treatment delivery. More than 20 unique ligands have been identified in the literature as showing specificity for the GPC3 receptor. Although several ligands are currently under clinical investigation as therapies for HCC, clinical translation of GPC3-targeting ligands as imaging agents is lacking. This review highlights the current landscape of ligands targeting GPC3 and describes their promising possibilities as imaging agents for HCC.

A 13-year-old girl suffered from worsen snoring and persistent bilateral nasal congestion for one year. Paranasal sinus computed tomography (CT) and magnetic resonance imaging (MRI) found nasopharyngeal passages and sinus were occupied with soft tissues and bilateral neck enlarged lymph nodes 6 months ago. Tumor markers were normal. The titers of anti-Epstein-Barr virus (EBV) IgM, anti-EBV IgG, early antigen (EA) IgG, and Epstein-Barr nuclear antigen (EBNA) IgG increased. 2-Deoxy-2-[fluorine-18]-fluoro-D-glucose (¹⁸F-FDG) positron emission tomography combined with CT (PET/CT) revealed thickened soft tissues in nasopharynx and oropharynx, enlarged multiple lymph nodes in the neck, bilateral armpits, abdominal cavity and retroperitoneum, and pelvic cavity, diffuse thickening of the gastric wall of the antrum with hypermetabolism. According to the age, situation, regions, and abnormal FDG uptake, an initial diagnosis of EBV-related lymphoma was made. However, the pathological results of the nasopharyngeal mass and the abdominal lymph node confirmed the final diagnosis of a B-cell type chronic active Epstein-Barr virus disease (CAEBV), a rare type of EBV associated lymphoproliferative disorder (LPD). After receiving adoptive immune cells therapy, the EBV load decreased. At present, the patient is being followed up.