18 F-MFBG PET/CT and MRI in Identifying Brain Metastases in a Posttreatment Neuroblastoma Patient.

ABSTRACT: A 7-year-old girl with known brain metastasis from neuroblastoma developed new onset of severe headache. A brain MRI confirmed known metastasis in the right frontal lobe of the brain without new abnormalities. The patient was enrolled in a clinical trial using 18 F-MFBG PET/CT to evaluate patients with neuroblastoma. The images confirmed abnormal activity in the known lesion in the right frontal lobe. In addition, the PET showed additional foci of abnormal activity in the left cerebellopontine region. A follow-up brain MRI study acquired 4 months later revealed abnormal signals in the same region.

The status of nuclear medicine in China: the first official national survey.

AIM/INTRODUCTION: The National Nuclear Medicine Quality Control Center of China conducted the first official survey to investigate the nationwide situation of nuclear medicine in 2020. The survey aimed to unveil the current nuclear medicine situation and its quality control in China. MATERIALS AND METHODS: The web-based survey was conducted and the data was collected via the National Clinical Improvement System (NCIS) of China from 1st April to 31st May 2021. RESULTS: A total of 808 institutes across 30 provinces responded to the national survey. For human resources, there are 4460 physicians, 3077 technologists, 339 physicists, and 309 radiochemists. There are 887 single-photon imaging instruments, including 823 SPECT or SPECT/CT, and 365 PET instruments including 314 PET/CT. Six hundred twenty-four institutes perform SPECT examinations and 319 institutes perform PET examinations. 60% of SPECT scans are bone scintigraphy. A total of 97% of PET scans use an [18F]F-FDG tracer. Furthermore, 587 institutes provide radionuclide therapy services but only 280 institutes have admission rooms. The top three radionuclide therapies are [131I] therapy of hyperthyroidism with 546 institutes, [89Sr] therapy of bone metastasis with 400 institutes, and [131I] therapy of differentiated thyroid cancer with 286 institutes. Finally, for the frequency of equipment quality control per year, there are about 67 times self-test within the department for SPECT instruments and 111 times for PET instruments on average in each province. There are about three failures of SPECT and five failures of PET on average per year in each province. There are 408 institutes (of 624 SPECT institutes) performing quality control of SPECT radiopharmaceuticals, 216 (of 319) for PET radiopharmaceuticals, and 373 (of 587) for radionuclide therapy. CONCLUSION: These results of the first official survey towards current status of nuclear medicine in China are the foundation for the establishment of the quality control management system.

Preclinical evaluation of the theranostic potential of 89Zr/177Lu-labeled anti-TROP-2 antibody in triple-negative breast cancer model.

BACKGROUND: Triple-negative breast cancer (TNBC) is one of the most lethal malignant tumors among women, characterized by high invasiveness, high heterogeneity, and lack of specific therapeutic targets such as estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. Trophoblast cell-surface antigen-2 (TROP-2) is a transmembrane glycoprotein over-expressed in 80% of TNBC patients and is associated with the occurrence, progress, and poor prognosis of TNBC. The TROP-2 targeted immunoPET imaging allows non-invasive quantification of the TROP-2 expression levels of tumors, which could help to screen beneficiaries most likely to respond to SG and predict the response. This study aimed to develop a 89Zr/177Lu-radiolabeled anti-TROP-2 antibody (NY003) for immunoPET and SPECT imaging, as well as radioimmunotherapy (RIT) in TROP-2 (+)TNBC tumor-bearing model. Based on the camelid antibody, we developed a TROP-2 targeted recombinant antibody NY003. NY003 was conjugated with DFO and DTPA for 89Zr and 177Lu radiolabelling, respectively. The theranostic potential of [89Zr]Zr-DFO-NY003/[177Lu]Lu-DTPA-NY003 was evaluated through immunoPET, SPECT imaging, and RIT studies in the subcutaneous TROP-2 positive TNBC xenograft mice model. RESULTS: The high binding affinity of NY003 to TROP-2 was verified through ELISA. The radiochemical purity of [89Zr]Zr-DFO-NY003/[177Lu]Lu-DTPA-NY003 exceeded 95% and remained stable within 144h p.i. in vitro. ImmunoPET and SPECT imaging showed the specific accumulation of [89Zr]Zr-DFO-NY003/[177Lu]Lu-DTPA-NY003 in MDA-MB-231 tumors and gradually increased with the time tested, significantly higher than that in control groups (P < 0.05). The strongest anti-tumor efficacy was observed in the high-dose of [177Lu]Lu-DTPA-NY003 group, followed by the low-dose group, the tumor growth was significantly suppressed by [177Lu]Lu-DTPA-NY003, the tumor volumes of both high- and low-dose groups were smaller than the control groups (P < 0.05). Ex vivo biodistribution and histological staining verified the results of in vivo imaging and RIT studies. CONCLUSION: As a drug platform for radiotheranostics, 89Zr/177Lu-radiolabeled anti-TROP-2 antibody NY003 could not only non-invasively screen the potential beneficiaries for optimizing SG ADC treatment but also suppressed the growth of TROP-2 positive TNBC tumors, strongly supporting the theranostic potential of [89Zr]Zr-DFO-NY003/[177Lu]Lu-DTPA-NY003.

99mTc-Labeled FAPI SPECT Imaging in Idiopathic Pulmonary Fibrosis: Preliminary Results.

AIM: Idiopathic pulmonary fibrosis (IPF) is associated with a poor prognosis, presenting the most aggressive form of interstitial lung diseases (ILDs). Activated fibroblasts are crucial for pathological processes. Fibroblast activation protein (FAP) inhibitor (FAPI) tracers would be promising imaging agents for these diseases. The purpose of this study was to evaluate a 99mTc-labeled FAPI tracer, 99mTc-HFAPI imaging in IPF patients. METHODS: Eleven IPF patients (nine males and two females; age range 55-75 year) were included in this pilot study. 99mTc-HFAPI serial whole-body scintigraphy at 5 min, 20 min, 40 min, 1 h, 2 h, 3 h, 4 h, and 6 h was acquired for dynamic biodistribution and dosimetry estimation in seven representative patients. SPECT/CT tomography fusion imaging of the chest region was performed in all patients at 4 h post-injection, which was considered as the optimal acquisition time. Dosimetry was calculated using OLINDA/EXM software (version 2.0; HERMES Medical Solutions). The quantified or semi-quantified standardized uptake values (SUVs) and lesion-to-background ratios (LBRs) of affected lung parenchyma were also calculated. The high-resolution CT (HRCT) stage was determined with visual evaluation, and the total HRCT score of each patient was measured using a weighting factor formula. Pulmonary function tests (PFTs) were recorded as well. Then, the relationships between the 99mTc-HFAPI results, disease extent on HRCT, and PFT results were investigated. RESULTS: Normal physiological uptake of 99mTc-HFAPI was observed mainly in the liver, intestinal tract, pancreas, gallbladder, and to a lesser extent in the spleen, kidneys, and thyroid, with no apparent retention in the blood circulation at the late time point. The mean injected activity of 99mTc-HFAPI was 813.4 MBq (range 695.6-888.0 MBq). No subjective side effects were noticed. The average whole-body effective dose was 0.0041 mSv/MBq per patient. IPF patients exhibited elevated pulmonary 99mTc-HFAPI uptake in abnormal lung regions, which was correlated with fibrotic regions on HRCT. Among different HRCT stage groups, both SUVmax and LBR showed significant differences (p < 0.001). The higher HRCT stage demonstrated significantly higher SUVmax and LBR. A linear correlation between 99mTc-HFAPI uptake and total HRCT score was observed for SUVmax (r = 0.7839, F = 54.41, p = 0.0094) and LBR (r = 0.7402, F = 56.33, p = 0.0092). 99mTc-HFAPI uptake also had moderate correlations with PFT results. CONCLUSIONS: Our preliminary data show that the 99mTc-HFAPI SPECT imaging is a promising new imaging modality in IPF patients. Investigations of its clinical value in monitoring disease progression and treatment response are needed in the future.

Hepatic Cavernous Hemangioma Mimicking Malignancy on 18 F-FDG PET/CT Imaging.

ABSTRACT: A 65-year-old woman was referred to our hospital because of a liver lesion revealed by ultrasound and CT in an outside institution. 18 F-FDG PET/CT images revealed an FDG-avid lesion in the left lateral lobe of the liver. Malignancy cannot be excluded. A subsequent resection was performed to remove the lesion. Postoperative pathology was hepatic cavernous hemangioma. This case suggests that PET/CT findings of FDG-avid hepatic cavernous hemangioma could mimic malignancy.

Increased Uptake of Brown Tumor in 99m Tc-HYNIC-TOC Scintigraphy Mimicking Postoperative Recurrence of Tumor-Induced Osteomalacia.

ABSTRACT: A 61-year-old man underwent a resection of tumor in the left tibia that caused osteomalacia 11 years ago. Postoperative bone pain and fatigue symptoms were briefly relieved but then recurred. To identify potential recurrent tumors, 99m Tc-HYNIC-TOC scintigraphy was performed. Images revealed an osteolytic lesion in the right tibia with increased uptake. The lesion was subsequently resected, which pathologically proved a brown tumor. Symptoms of bone pain and weakness caused by osteomalacia did not relieve 4 months after the operation. Here, we present a rare case of brown tumor with high activity on 99m Tc-HYNIC-TOC SPECT/CT, mimicking a culprit tumor of osteomalacia.

Comparison of 68Ga-DOTA-FAPI-04 and 18F-FDG PET/CT in Patients With SAPHO Syndrome.

PATIENTS AND METHODS: 68Ga-DOTA-FAPI-04 PET/CT was performed on a cohort of 21 patients with known SAPHO syndrome. All patients underwent 68Ga-DOTA-FAPI-04 and 18F-FDG PET/CT on 2 consecutive days. The positive rates of the PET/CT scans at the sites of the osteoarticular symptom, the uptake values, and agreement with clinical osteoarticular symptom were compared. RESULTS: A total of 38 sites of involvement were detected. 18F-FDG PET/CT revealed 28 lesions. In contrast, 68Ga-DOTA-FAPI-04 PET/CT detected not only all lesions shown on 18F-FDG PET/CT but additional 10 lesions. 68Ga-DOTA-FAPI-04 scan also demonstrated significantly higher uptake and target-to-background ratio than 18F-FDG studies in the skeletal involvements. The agreement between 68Ga-DOTA-FAPI-04-positive lesions and current osteoarticular lesions was substantial (κ = 0.79, P < 0.001), whereas 18F-FDG had low to moderate agreement with clinical symptoms (κ = 0.52, P < 0.001). CONCLUSIONS: 68Ga-DOTA-FAPI-04 has potential as a promising imaging agent for the evaluation of SAPHO syndrome.

Lung Nodule as Culprit Lesion Causing Recurrent Tumor-Induced Osteomalacia Revealed by 68 Ga-DOTATATE PET/CT.

ABSTRACT: Neoplasms that cause tumor-induced osteomalacia are very rarely located in the lung. A 27-year-old man underwent a surgery in the right femoral head to remove the tumor that induced osteomalacia 8 years ago with complete symptomatic relief. However, his bone pain occurred again recently, which lead to suspicion of a recurrent tumor-induced osteomalacia. 68 Ga-DOTATATE PET/CT images showed a pulmonary nodule with mildly increased uptake along with increased activity in the left foot. The pulmonary nodule was subsequently resected and was pathologically confirmed as a phosphaturic mesenchymal tumor. The symptoms were completely relieved postsurgery.

Deep learning model for automatic image quality assessment in PET.

BACKGROUND: A variety of external factors might seriously degrade PET image quality and lead to inconsistent results. The aim of this study is to explore a potential PET image quality assessment (QA) method with deep learning (DL). METHODS: A total of 89 PET images were acquired from Peking Union Medical College Hospital (PUMCH) in China in this study. Ground-truth quality for images was assessed by two senior radiologists and classified into five grades (grade 1, grade 2, grade 3, grade 4, and grade 5). Grade 5 is the best image quality. After preprocessing, the Dense Convolutional Network (DenseNet) was trained to automatically recognize optimal- and poor-quality PET images. Accuracy (ACC), sensitivity, specificity, receiver operating characteristic curve (ROC), and area under the ROC Curve (AUC) were used to evaluate the diagnostic properties of all models. All indicators of models were assessed using fivefold cross-validation. An image quality QA tool was developed based on our deep learning model. A PET QA report can be automatically obtained after inputting PET images. RESULTS: Four tasks were generated. Task2 showed worst performance in AUC,ACC, specificity and sensitivity among 4 tasks, and task1 showed unstable performance between training and testing and task3 showed low specificity in both training and testing. Task 4 showed the best diagnostic properties and discriminative performance between poor image quality (grade 1, grade 2) and good quality (grade 3, grade 4, grade 5) images. The automated quality assessment of task 4 showed ACC = 0.77, specificity = 0.71, and sensitivity = 0.83, in the train set; ACC = 0.85, specificity = 0.79, and sensitivity = 0.91, in the test set, respectively. The ROC measuring performance of task 4 had an AUC of 0.86 in the train set and 0.91 in the test set. The image QA tool could output basic information of images, scan and reconstruction parameters, typical instances of PET images, and deep learning score. CONCLUSIONS: This study highlights the feasibility of the assessment of image quality in PET images using a deep learning model, which may assist with accelerating clinical research by reliably assessing image quality.

Direct attenuation correction for 99mTc-3PRGD2 chest SPECT lung cancer images using deep learning.

Introduction: The attenuation correction technique of single photon emission computed tomography (SPECT) images is essential for early diagnosis, therapeutic evaluation, and pharmacokinetic studies of lung cancer. 99mTc-3PRGD2 is a novel radiotracer for the early diagnosis and evaluation of treatment effects of lung cancer. This study preliminary discusses the deep learning method to directly correct the attenuation of 99mTc-3PRGD2 chest SPECT images. Methods: Retrospective analysis was performed on 53 patients with pathological diagnosis of lung cancer who received 99mTc-3PRGD2 chest SPECT/CT. All patients' SPECT/CT images were reconstructed with CT attenuation correction (CT-AC) and without attenuation correction (NAC). The CT-AC image was used as the reference standard (Ground Truth) to train the attenuation correction (DL-AC) SPECT image model using deep learning. A total of 48 of 53 cases were divided randomly into the training set, the remaining 5 were divided into the testing set. Using 3D Unet neural network, the mean square error loss function (MSELoss) of 0.0001 was selected. A testing set is used to evaluate the model quality, using the SPECT image quality evaluation and quantitative analysis of lung lesions tumor-to-background (T/B). Results: SPECT imaging quality metrics between DL-AC and CT-AC including mean absolute error (MAE), mean-square error (MSE), peak signal-to-noise ratio (PSNR), structural similarity (SSIM), normalized root mean square error (NRMSE), and normalized Mutual Information (NMI) of the testing set are 2.62 ± 0.45, 58.5 ± 14.85, 45.67 ± 2.80, 0.82 ± 0.02, 0.07 ± 0.04, and 1.58 ± 0.06, respectively. These results indicate PSNR > 42, SSIM > 0.8, and NRMSE < 0.11. Lung lesions T/B (maximum) of CT-AC and DL-AC groups are 4.36 ± 3.52 and 4.33 ± 3.09, respectively (p = 0.81). There are no significant differences between two attenuation correction methods. Conclusion: Our preliminary research results indicate that using the DL-AC method to directly correct 99mTc-3PRGD2 chest SPECT images is highly accurate and feasible for SPECT without configuration with CT or treatment effect evaluation using multiple SPECT/CT scans.

[18F]MFBG PET/CT outperforming [123I]MIBG SPECT/CT in the evaluation of neuroblastoma.

PURPOSE: Iodine 123 labeled meta-iodobenzylguanidine ([123I]MIBG) scan with SPECT/CT imaging is one of the most commonly used imaging modalities in the evaluation of neuroblastoma. [18F]-meta-fluorobenzylguanidine ([18F]MFBG) is a novel positron emission tomography (PET) tracer which was reported to have a similar biodistribution to [123I]MIBG. However, the experience of using [18F]MFBG PET/CT in the evaluation of patients with neuroblastoma is limited. This preliminary investigation aims to assess the efficacy of [18F]MFBG PET/CT in the evaluation of neuroblastomas in comparison to [123I]MIBG scans with SPECT/CT. MATERIALS AND METHODS: In this prospective, single-center study, 40 participants (mean age 6.0 ± 3.7 years) with history of neuroblastoma were enrolled. All children underwent both [123I]MIBG SPECT/CT and [18F]MFBG PET/CT studies. The number of lesions and the Curie scores revealed by each imaging method were recorded. RESULTS: Six patients had negative findings on both [123I]MIBG and [18F]MFBG studies. Four of the 34 patients (11.8%) were negative on [123I]MIBG but positive on [18F]MFBG, while 30 patients were positive on both [123I]MIBG and [18F]MFBG studies. In these 34 patients, [18F]MFBG PET/CT identified 784 lesions while [123I]MIBG SPECT/CT detected 532 lesions (p < 0.001). The Curie scores obtained from [18F]MFBG PET/CT (11.32 ± 8.18, range 1-27) were statistically higher (p < 0.001) than those from [123I]MIBG SPECT/CT (7.74 ± 7.52, range 0-26). 30 of 34 patients (88.2%) with active disease on imaging had higher Curie scores based on the [18F]MFBG study than on the [123I]MIBG imaging. CONCLUSION: [18F]MFBG PET/CT shows higher lesion detection rate than [123I]MIBG SPECT/CT in the evaluation of pediatric patients with neuroblastoma. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov : NCT05069220 (Registered: 25 September 2021, retrospectively registered); Institute Review Board of Peking Union Medical College Hospital: ZS-2514.

Prognostic value of pretreatment 18F-FDG PET/CT metabolic parameters in esophageal high-grade neuroendocrine carcinoma: A bicenter retrospective study.

Objective: The aim of this bicentric retrospective study was to assess the prognostic value of 18F-FDG PET/CT in patients with esophageal high-grade neuroendocrine carcinoma (NECs). Methods: From the database of two centers, 28 patients affected by esophageal high-grade NECs who underwent 18F-FDG PET/CT before treatment were retrospectively reviewed. Metabolic parameters (SUVmax, SUVmean, tumor-to-blood-pool SUV ratio (TBR), tumor-to-liver SUV ratio (TLR), metabolic tumor volume (MTV), total lesion glycolysis (TLG)) of the primary tumor were measured. Univariate and multivariate analyses were performed for progression-free survival (PFS) and overall survival (OS). Results: After a median follow-up period of 22 months, disease progression occurred in 11 (39.3%) patients, and death occurred in 8 (28.6%) patients. The median PFS was 34 months, and the median OS was not reached. Univariate analyses revealed that among metabolic parameters, only MTV and TLG were significant prognostic factors, while among clinical variables, only distant metastasis was a significant factor for both PFS and OS (P< 0.05). On multivariate analyses, MTV and TLG were independent prognostic factors for both PFS and OS (P< 0.05). Conclusions: In patients with esophageal high-grade NEC, MTV and TLG measured on pretreatment 18F-FDG PET/CT are independently prognostic factors for predicting PFS and OS, and might be used as quantitative prognostic imaging biomarkers.

Characterization and Double-Antibody Sandwich ELISA Application of a Monoclonal Antibody Against Akabane Virus Nucleocapsid Protein.

BACKGROUND: Akabane virus (AKAV) is a Culicoides-borne Orthobunyavirus that is teratogenic to the fetus of cattle and small ruminant species. OBJECTIVE: This study aimed to develop an effective diagnostic assay for the detection of AKAV using produced monoclonal antibody (mAb). METHOD: First, the mAb against N protein of AKAV was produced and characterized by Western blot (WB) and indirect immunofluorescence (IFA) assays. Then, the linear epitope of AKAV N protein against the mAb was identified and the mAb was applied to establish a double-antibody sandwich ELISA (DAS-ELISA). RESULTS: One AKAV N-reactive monoclonal mAb was generated and designated as 2D3. WB and IFA assays indicated that 2D3 could react with both recombinant N protein and AKAV isolate TJ2016. The linear epitope recognized by mAb 2D3 was located at amino acids 168-182 of AKAV N protein. The DAS-ELISA established on based mAb 2D3 was able to detect both the purified AKAV N protein (with a detection limit of 6.25 ng/mL) and AKAV-infected cell culture supernatant (with a detection limit of 250 TCID50/mL). CONCLUSIONS: Taken together, we successfully prepared a mAb 2D3 against AKAV N protein and identified its corresponding linear epitope, and then established a DAS-ELISA for the detection of AKAV antigen. HIGHLIGHTS: A produced mAb against AKAV N protein was used to define a linear epitope of AKAV and establish a DAS-ELISA for AKAV antigen detection.

18 F-MFBG PET/CT Is an Effective Alternative of 68 Ga-DOTATATE PET/CT in the Evaluation of Metastatic Pheochromocytoma and Paraganglioma.

PURPOSE: The current guidelines state that the functional imaging choice in the evaluation of metastatic pheochromocytoma and paraganglioma (PPGL) is 68 Ga-DOTATATE PET/CT. 18 F-meta-fluorobenzylguanidine ( 18 F-MFBG) is a new PET tracer and an analog of meta-iodobenzylguanidine (MIBG). This study aimed to compare 18 F-MFBG and 68 Ga-DOTATATE PET/CT in patients with metastatic PPGL. PATIENTS AND METHODS: Twenty-eight patients with known metastatic PPGL were prospectively recruited for this study. All patients underwent both 18 F-MFBG and 68 Ga-DOTATATE PET/CT studies within 1 week. Lesion numbers detected were compared between these 2 studies. RESULTS: 18 F-MFBG PET/CT was positive for detecting metastases in all patients, whereas positive results of 68 Ga-DOTATATE PET/CT were in 27 (96.4%) patients. A total of 686 foci of metastatic lesions were detected by both 18 F-MFBG and 68 Ga-DOTATATE imaging. In addition, 33 foci of abnormal activity were only detected by 18 F-MFBG, whereas 16 foci were only shown on 68 Ga-DOTATATE PET/CT. CONCLUSIONS: Our data suggest that 18 F-MFBG PET/CT is an effective imaging method in the evaluation of metastatic PPGL and could be alternative of 68 Ga-DOTATATE PET/CT in this clinical setting.

A deep learning-based post-processing method for automated pulmonary lobe and airway trees segmentation using chest CT images in PET/CT.

Background: The proposed algorithm could support accurate localization of lung disease. To develop and validate an automated deep learning model combined with a post-processing algorithm to segment six pulmonary anatomical regions in chest computed tomography (CT) images acquired during positron emission tomography/computed tomography (PET/CT) scans. The pulmonary regions have five pulmonary lobes and airway trees. Methods: Patients who underwent both PET/CT imaging with an extra chest CT scan were retrospectively enrolled. The pulmonary segmentation of six regions in CT was performed via a convolutional neural network (CNN) of DenseVNet architecture with some post-processing algorithms. Three evaluation metrics were used to assess the performance of this method, which combined deep learning and the post-processing method. The agreement between the combined model and ground truth segmentations in the test set was analyzed. Results: A total of 640 cases were enrolled. The combined model, which involved deep learning and post-processing methods, had a higher performance than the single deep learning model. In the test set, the all-lobes overall Dice coefficient, Hausdorff distance, and Jaccard coefficient were 0.972, 12.025 mm, and 0.948, respectively. The airway-tree Dice coefficient, Hausdorff distance, and Jaccard coefficient were 0.849, 32.076 mm, and 0.815, respectively. A good agreement was observed between our segmentation in every plot. Conclusions: The proposed model combining two methods can automatically segment five pulmonary lobes and airway trees on chest CT imaging in PET/CT. The performance of the combined model was higher than the single deep learning model in each region in the test set.

Tumor-induced osteomalacia combined with acromegaly: A case report.

Both acromegaly and tumor-induced osteomalacia (TIO) are rare diseases caused by an excess hormone secreted by neuroendocrine neoplasms, which are growth hormone (GH) and fibroblast growth factor 23 (FGF23), respectively. GH elevates phosphate reabsorption via the effect of insulin-like factor 1 (IGF-1), while FGF23 inhibits phosphate reabsorption and reduces serum phosphate level markedly. A patient who developed a typical acromegaly appearance but was accompanied with height loss and hypophosphatemia for 2 years visited our hospital. Laboratory investigations showed GH and IGF-1 hypersecretion, as well as hypophosphatemia caused by renal phosphate wasting. Magnetic resonance image revealed a pituitary somatotroph adenoma. Octreoscan scintigraphy also found a causative tumor on the right foot for hypophosphatemia. Then, he underwent resection of the tumor on the right foot. His serum phosphate returned to normal immediately but elevated gradually. Then, we removed the pituitary adenoma of the patient, and the GH and phosphate levels returned to the normal range. Here, we report the first case with acromegaly combined with TIO, the changing process of his phosphate concentration suggests an interesting concurrent effect of excess GH and FGF23 in this rare condition.

Deep learning-based automated segmentation of eight brain anatomical regions using head CT images in PET/CT.

OBJECTIVE: We aim to propose a deep learning-based method of automated segmentation of eight brain anatomical regions in head computed tomography (CT) images obtained during positron emission tomography/computed tomography (PET/CT) scans. The brain regions include basal ganglia, cerebellum, hemisphere, and hippocampus, all split into left and right. MATERIALS AND METHODS: We enrolled patients who underwent both PET/CT imaging (with an extra head CT scan) and magnetic resonance imaging (MRI). The segmentation of eight brain regions in CT was achieved by using convolutional neural networks (CNNs): DenseVNet and 3D U-Net. The same segmentation task in MRI was performed by using BrainSuite13, which was a public atlas label method. The mean Dice scores were used to assess the performance of the CNNs. Then, the agreement and correlation of the volumes of the eight segmented brain regions between CT and MRI methods were analyzed. RESULTS: 18 patients were enrolled. Four of the eight brain regions obtained high mean Dice scores (> 0.90): left (0.978) and right (0.912) basal ganglia and left (0.945) and right (0.960) hemisphere. Regarding the agreement and correlation of the brain region volumes between two methods, moderate agreements were observed on the left (ICC: 0.618, 95% CI 0.242, 0.835) and right (ICC: 0.654, 95% CI 0.298, 0.853) hemisphere. Poor agreements were observed on the other regions. A moderate correlation was observed on the right hemisphere (Spearman's rho 0.68, p = 0.0019). Lower correlations were observed on the other regions. CONCLUSIONS: The proposed deep learning-based method performed automated segmentation of eight brain anatomical regions on head CT imaging in PET/CT. Some regions obtained high mean Dice scores and the agreement and correlation results of the segmented region volumes between two methods were moderate to poor.

A Novel, Reverse Transcription, Droplet Digital PCR Assay for the Combined, Sensitive Detection of Severe Acute Respiratory Syndrome Coronavirus 2 with Swine Acute Diarrhea Syndrome Coronavirus.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread over the world since its emergence. Although the dominant route of SARS-CoV-2 infection is respiratory, a number of studies revealed infection risk from contaminated surfaces and products, including porcine-derived food and other products. The SARS-CoV-2 outbreak has been severely threatening public health, and disrupting porcine products trade and the pig industry. Swine acute diarrhea syndrome coronavirus (SADS-CoV), which was responsible for large-scale, fatal disease in piglets, emerged in 2017 and has caused enormous economic losses in the pig industry. Currently, reverse transcription real-time PCR (RT-rPCR) is the gold standard method for SARS-CoV-2 diagnosis and is most commonly used for SADS-CoV detection. However, inaccurate detection of the SARS-CoV-2 infection obtained by RT-rPCR is increasingly reported, especially in specimens with low viral load. OBJECTIVE: This study aimed to develop an accurate reverse transcription droplet digital PCR (RT-ddPCR) assay for the detection of SARS-CoV-2 and SADS-CoV simultaneously. METHODS: Two pairs of primers and one double-quenched probe targeting the RNA-dependent RNA polymerase (RDRP) region of the open reading frame 1ab (ORF1ab) gene of SARS-CoV-2 and the corresponding ORF1ab region of SADS-CoV were designed to develop the RT-ddPCR assay. The sensitivity, specificity, repeatability, and reproducibility were tested using complementary RNAs (cRNAs) and clinical specimens. RESULTS: The detection limits of RT-ddPCR were 1.48 ± 0.18 and 1.38 ± 0.17 copies in a 20 µL reaction for SARS-CoV-2 and SADS-CoV cRNAs, respectively (n = 8), showing approximately 4- and 10-fold greater sensitivity than the RT-rPCR assay. This assay also exhibited good specificity, repeatability, and reproducibility. CONCLUSION: The established RT-ddPCR assay was shown to be a highly effective, accurate, and reliable method for the sensitive detection of SARS-CoV-2 and SADS-CoV. HIGHLIGHTS: This RT-ddPCR assay could be used to detect both SARS-CoV-2 and SADS-CoV in a sample with one double-quenched probe, and is also the first reported RT-ddPCR assay for SADS-CoV detection.

MIBG Uptake in a Gastric Gastrointestinal Stromal Tumor.

ABSTRACT: MIBG scintigraphy is the imaging choice in the evaluation of pheochromocytoma and neuroblastoma. 131 I-MIBG uptake by gastrointestinal stromal tumors was rare. Here we report a case in which an increased 131 I-MIBG activity in an endoluminal gastric gastrointestinal stromal tumor was noted.