Positron Emission Tomography/computed Tomography Research Articles

Evaluation of patients' radiation doses and establishment of institutional diagnostic reference levels in nuclear medicine in Oman.

This study aimed to develop diagnostic reference levels (DRLs) in Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) and Positron Emission Tomography/Computed Tomography (PET/CT) imaging for the most frequent SPECT/CT and PET/CT examinations performed at our institution. A total of 1134 adult patients, who have undergone SPECT/CT and PET/CT scanning over a period of 4years (2018-2021), were included. The scans consisted of 401 PET/CT and 733 SPECT/CT scans. The CT dosimetry data [CT-dose-index (CTDIvol), dose-length-product (DLP)] and administered activities were collected. The DRLs were calculated for CTDIvol, DLP and administrated activity. The estimated DRLs are given as [median CTDIvol (mGy):median DLP (mGy.cm):median administrated activity (MBq)]: whole body PET/CT: 1.88:175:259; brain PET/CT: 12.9:300:239; cardiac PET/CT: 1.34:32:368; bone SPECT/CT: 2.68:116:763; MPI SPECT/CT (stress-rest): 1.49:52:751-721; parathyroid SPECT/CT: 3.1:126:779; thyroid uptake SPECT: 3.52:147:195; thyroid post-ablation SPECT/CT: 3.85:160:NA. The derived DRLs have allowed careful monitoring of doses delivered to patients and could act as a trigger to investigate doses that systematically exceeds the derived DRLs.

Fully automated classification of pulmonary nodules in positron emission tomography-computed tomography imaging using a two-stage multimodal learning approach.

Lung cancer is a malignant tumor, for which pulmonary nodules are considered to be significant indicators. Early recognition and timely treatment of pulmonary nodules can contribute to improving the survival rate of patients with cancer. Positron emission tomography-computed tomography (PET/CT) is a noninvasive, fusion imaging technique that can obtain both functional and structural information of lung regions. However, studies of pulmonary nodules based on computer-aided diagnosis have primarily focused on the nodule level due to a reliance on the annotation of nodules, which is superficial and unable to contribute to the actual clinical diagnosis. The aim of this study was thus to develop a fully automated classification framework for a more comprehensive assessment of pulmonary nodules in PET/CT imaging data. We developed a two-stage multimodal learning framework for the diagnosis of pulmonary nodules in PET/CT imaging. In this framework, Stage I focuses on pulmonary parenchyma segmentation using a pretrained U-Net and PET/CT registration. Stage II aims to extract, integrate, and recognize image-level and feature-level features by employing the three-dimensional (3D) Inception-residual net (ResNet) convolutional block attention module architecture and a dense-voting fusion mechanism. In the experiments, the proposed model's performance was comprehensively validated using a set of real clinical data, achieving mean scores of 89.98%, 89.21%, 84.75%, 93.38%, 86.83%, and 0.9227 for accuracy, precision, recall, specificity, F1 score, and area under curve values, respectively. This paper presents a two-stage multimodal learning approach for the automatic diagnosis of pulmonary nodules. The findings reveal that the main reason for limiting model performance is the nonsolitary property of nodules in pulmonary nodule diagnosis, providing direction for future research.

Added prognostic value of visually estimated coronary artery calcium among heart transplant recipients

BackgroundCardiac hybrid positron emission tomography/computed tomography (PET/CT) has become a valid screening modality for cardiac allograft vasculopathy (CAV) following HT. Visually estimated coronary artery calcium (VECAC) can be quantified from CT images obtained as part of PET/CT and has been shown to be associated with adverse cardiovascular outcomes in coronary artery disease. We investigated the prognostic value of VECAC following heart transplantation (HT). MethodsA retrospective analysis of 430 consecutive adult HT patients who underwent 13N-ammonia cardiac PET/CT from 2016-2019 with follow-up through October 15, 2022, was performed. VECAC categories included: VECAC 0, VECAC 1-9, VECAC 10-99, and VECAC 100+. The association between VECAC categories and outcomes was assessed using univariable and multivariable proportional hazards regression. The primary outcome was death/retransplantation. ResultsThe cohort was 73% male, 33% had diabetes, 67% had estimated glomerular filtration rate<60 mL/min, median age was 61 years, and median time since HT was 7.5 years. VECAC alone was insufficiently sensitive to screen for CAV. During a median follow-up of 4.2 years ninety patients experienced death or retransplantation. Compared with those with VECAC 0, patients VECAC 10-99 (HR 2.25, 95% CI 1.23-4.14, p=0.009) and VECAC 100+ (HR 3.42, 95% CI 1.96-5.99, p<0.001) experienced an increased risk of death/retransplantation. The association was similar for cardiovascular death and cardiovascular hospitalization. After adjusting for other predictors of death/retransplantation, VECAC 10-99 (VECAC 10-99: aHR 1.95, 95% CI 1.03-3.71 p=0.04) and VECAC 100+ (VECAC 100+: aHR 2.33, 95% CI 1.17-4.63, p=0.02) remained independently associated with death/retransplantation. ConclusionsVECAC is an independent prognostic marker of death/retransplantation following HT and merits inclusion as a part of post-HT surveillance PET/CT.

Diagnostic Performance and Interobserver Agreement of Diuretic 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnosis of Upper Urinary Tract Cancer.

Previous reports attempted to evaluate bladder cancer using 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) by washing out the excreted FDG with a diuretic. The purpose of this study was to evaluate the value of diuretic FDG PET/plain CT (drtPET/CT) and diuretic FDG PET/contrast-enhanced CT (drtPET/ceCT) in the assessment of upper urinary tract cancers. A total of 66 patients underwent drtPET/CTfor suspected upper urinary tract cancer (UUTC). The study targeted 29 patients who were strongly suspected of having UUTC and underwent magnetic resonance imaging (MRI) of the upper urinary tract. A total of 29 (24 male, five female) patients, with a mean ± SDage of 73 ± 3 (range, 43-84) years, had a suspected neoplasm in the upper urinary tract. They underwent FDG PET/plain and contrast-enhanced CT before and after a diuretic and MRIincluding diffusion-weighted imaging (DWI). A urologist and a physician board-certified in nuclear medicine and radiology independently interpreted the standard PET/CT (stdPET/CT), drtPET/CT, drtPET/ceCT, ceCT, and MRI with DWI images. Interobserver agreement and the diagnostic performance of each modality were evaluated. The kappa values of stdPET/CT, drtPET/CT, drtPET/ceCT, ceCT, and MRI were 0.381, 0.567, 0.7031, 0.448, and 0.185, respectively, with drtPET/ceCT showing the highest kappa value and the only one with good interobserver agreement (>60%). The area under the curve of drtPET/ceCT was 0.92, which was significantly higher than those of stdPET/CT (P=0.027) and MRI (P=0.047). In the present study, drtPET/ceCT had the best diagnostic performance and the highest interobserver agreement for detecting upper urinary tract urothelial cancers.

Predictive value of SUVmax from initial 18F-FDG PET/CT scans for treatment outcomes in endometrial cancer patients undergoing fertility sparing management

ObjectiveTo evaluate whether the maximum standardized uptake value (SUVmax) from initial 18F-FDG PET/CT (fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography) scans could be a predictor of complete response and recurrence in...

Peptide-based immuno-PET/CT monitoring of dynamic PD-L1 expression during glioblastoma radiotherapy

Real-time, noninvasive programmed death-ligand 1 (PD-L1) testing using molecular imaging has enhanced our understanding of the immune environments of neoplasms and has served as a guide for immunotherapy. However, the utilization of radiotracers in the imaging of human brain tumors using positron emission tomography/computed tomography (PET/CT) remains limited. This investigation involved the synthesis of [18F]AlF-NOTA-PCP2, which is a novel peptide-based radiolabeled tracer that targets PD-L1, and evaluated its imaging capabilities in orthotopic glioblastoma (GBM) models. Using this tracer, we could noninvasively monitor radiation-induced PD-L1 changes in GBM. [18F]AlF-NOTA-PCP2 exhibited high radiochemical purity (>95%) and stability up to 4 hours after synthesis. It demonstrated specific, high-affinity binding to PD-L1 in vitro and in vivo, with a dissociation constant of 0.24 nM. PET/CT imaging, integrated with contrast-enhanced magnetic resonance imaging, revealed significant accumulation of [18F]AlF-NOTA-PCP2 in orthotopic tumors, correlating with blood–brain barrier disruption. After radiotherapy (15 Gy), [18F]AlF-NOTA-PCP2 uptake in tumors increased from 9.51% ± 0.73% to 12.04% ± 1.43%, indicating enhanced PD-L1 expression consistent with immunohistochemistry findings. Fractionated radiation (5 Gy × 3) further amplified PD-L1 upregulation (13.9% ± 1.54% ID/cc) compared with a single dose (11.48% ± 1.05% ID/cc). Taken together, [18F]AlF-NOTA-PCP2 may be a valuable tool for noninvasively monitoring PD-L1 expression in brain tumors after radiotherapy.

Integrating myocardial metabolic imaging and stress myocardial contrast echocardiography to improve the diagnosis of coronary microvascular diseases in rabbits.

Persistent challenges associated with misdiagnosis and underdiagnosis of coronary microvascular disease (CMVD) necessitate the exploration of noninvasive imaging techniques to enhance diagnostic accuracy. Therefore, we aimed to integrate multimodal imaging approaches to achieve a higher diagnostic rate for CMVD using high-quality myocardial metabolism imaging (MMI) and myocardial contrast echocardiography (MCE). This combination diagnostic strategy may help address the urgent need for improved CMVD diagnosis. In this study, we established five distinct pretreatment groups, each consisting of nine male rabbit: a fasted group, a nonfasted group, a sugar load group, an acipimox group, and a combination group of nonfasted rabbits administered insulin. Moreover, positron emission tomography-computed tomography (PET/CT) scan windows were established at 30-, 60-, and 90-minute intervals. We developed 10 CMVD models and conducted a diagnosis of CMVD through an integrated analysis of MMI and MCE, including image acquisition and processing. For each heart segment, we calculated the standardized uptake value (SUV) based on body weight (SUVbw), as well as certain ratios of SUV including SUV of the heart (SUVheart) to that of the liver (SUVliver) and SUVheart to SUV of the lung (SUVlung). Additionally, we obtained three coronary SUVbw uptake values. To clarify the relationship between SUVbw uptake values and echocardiographic parameters of the myocardial contrast agent more thoroughly, we conducted a comprehensive analysis across different pretreatment protocols. Receiver operating characteristic (ROC) curve analysis was employed to evaluate the diagnostic accuracy of each parameter in the context of CMVD. In the context of MMI, the nonfasted-plus-insulin group, as observed during the 60-minute examination, exhibited a noteworthy total 18F-fluorodeoxyglucose (18F-FDG) uptake of 47.44±6.53 g/mL, which was found to be statistically different from the other groups. To ascertain the reliability of the results, two double-blind investigators independently assessed the data and achieved a good level of agreement, according to the intraclass correlation coefficient (ICC) (0.957). The SUVbw of the nonfasted-plus-insulin group exhibited a moderate correlation with the microvascular blood flow reserve (MBFR) parameters derived from the MCE examination, as evidenced by a r value of 0.686. For the diagnosis of CMVD disease, the diagnostic accuracy of the combined diagnostic method [area under the curve (AUC) =0.789; 95% confidence interval (CI): 0.705-0.873] was significantly higher than that of the MBFR (AUC =0.697; 95% CI: 0.597-0.797) and SUVbw (AUC =0.715; 95% CI: 0.622-0.807) methods (P<0.05). Our study demonstrated the feasibility of a simple premedication approach involving free feeding and intravenous insulin in producing high-quality gated heart 18F-FDG PET/CT images in adult male New Zealand white rabbits. This technique holds considerable potential for ischemic heart disease research in rabbits and can enhance CMVD diagnosis via the comprehensive assessment of myocardial metabolism and perfusion.

Evaluating the role of sarcopenia and [18F]FDG PET/CT parameters in prognosis of pancreatic ductal adenocarcinoma

This study investigates the relationship between 18F-fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) metabolic parameters, clinicopathological characteristics, and sarcopenia in patients with pancreatic ductal adenocarcinoma (PDAC) and evaluates their prognostic roles. Material and methodsThe primary tumor's maximum standard uptake (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) values, as well as clinicopathological factors, were evaluated retrospectively. Computed tomography (CT) was used to assess the skeletal muscle index (SMI). Sarcopenia was defined based on SMI calculated at the third lumbar vertebra (L3). SMI cut-off values ​​for sarcopenia were accepted as 44.77 cm2/m2 for men and 32.50 cm2/m2 for women. The primary endpoint was the overall survival (OS). OS data were analyzed by the Kaplan-Meier method and compared using the log-rank test. To identify predictive factors for sarcopenia, multivariable logistic regression was used following univariable logistic regression. Cox proportional hazards regression analyses were used to find predictors of OS. ResultsOf the 86 patients included in the study, 37 (43%) were diagnosed with sarcopenia. Compared with non-sarcopenic patients, sarcopenia was observed in older patients (P=0,028) and patients with lower body mass index (BMI) (p=0,001). Age and BMI independently predicted sarcopenia. Univariate analysis identified sarcopenia, advanced stage, and higher primary tumor TLG as significant predictors of overall survival. Multivariate Cox regression analysis revealed that the advanced tumor stage (p=0.017) and higher TLG (p=0,042) independently predicted OS. The median OS was 9.4 months in non-sarcopenic patients and 5.0 months in sarcopenic patients (p=0,021). ConclusionIn this study cohort, advanced-stage disease and higher primary tumor TLG were identified as independent predictors of OS in patients with PDAC. Additionally, we emphasize the importance of incorporating [18F]FDG PET/CT-derived sarcopenia assessments into the prognostic evaluation and clinical management of PDAC patients. While sarcopenia was associated with shorter OS in univariate analysis, it was not an independent predictor in multivariate analysis.

Polymyalgia rheumatica: What's new?

Currently, only 25% of all polymyalgia rheumatica (PMR) patients are referred to specialists. An expert committee has recently recommended confirmation of diagnosis by specialist care. This can help to avoid misdiagnoses and hospital stays and can result in lower glucocorticoid doses.Using ultrasound, magnetic resonance imagining (MRI), or positron emission tomography-computed tomography (PET-CT), typical periarticular inflammatory changes are observed, especially in the shoulder and pelvic girdle area. However, for clinical use, ultrasound is usually sufficient.In 20-25% of newly diagnosed PMR patients without symptoms of giant cell arteritis (GCA), GCA can be detected through vascular ultrasound. These patients require higher glucocorticoid doses in analogy to GCA therapy. There is growing awareness of a joint GCA-PMR spectrum disease.Glucocorticoids remain the primary treatment. The interleukin-6 inhibitor Sarilumab has recently been approved in the USA for patients with recurrent PMR. Studies have also demonstrated the effectiveness of Tocilizumab in PMR.

Four-dimensional computed tomography and ultrasonography for prediction of pathological parathyroid location: a retrospective review of a single surgeon's patients at a single institution.

Pre-operative imaging is a well-established practice for managing hyperparathyroidism with the plan for excision; however, there is a paucity of information regarding the success rate of concordant imaging studies. Our goal was to compare the accuracy (sensitivity) of four-dimensional computed tomography (4DCT) and ultrasound (US) when predicting the side and quadrant of parathyroid lesions, confirmed with surgical location (from a single surgeon). A retrospective review of 437 patients from a single surgeon undergoing parathyroidectomy from December 2013 to January 2020 at an academic medical center was performed. Masses >5 mm in dimension in eutopic parathyroid locations were identified as possible parathyroid lesions on 4DCT. A unique codified system was utilized to accurately record imaging results for each modality and compared to surgical findings. Four hundred and thirty-seven patients underwent parathyroid surgery, of those 431 underwent 4DCT, 413 underwent US, and 408 underwent both. 4DCT accurately lateralized lesions in 319 (74.0%; N=431). US lateralized lesions in 265 (64.2%; N=413). The sensitivity for lateralization was 81.2% and 69.9% for 4DCT and US, respectively. 4DCT and US identify the majority of parathyroid lesions. 4DCT outperformed US in lateralization yet both modalities remain useful and are complimentary in planning for successful parathyroidectomy. Newer imaging approaches such as 18F-choline positron emission tomography/computed tomography (PET/CT) and artificial intelligence as an augmentation to imaging review may play in role to identify parathyroid adenomas/hyperplasia, but their roles have yet to be clearly defined.

Physical function is associated with cognitive status, brain amyloid-beta deposition, and blood biomarkers in Chinese Han population.

The physical function of elderly individuals reflects whether they have had a history of regular physical activity over the long term. Such indicators have been found to have a certain connection with cognitive function these years. However, there is limited research that associates it with mechanisms such as cerebral Aβ deposition. We aim to investigate this relationship and unveil the underlying mechanisms. Physical function and cognition data of 4189 participants were obtained from the Chinese preclinical Alzheimer's disease study. Participants were divided into six groups according to disease severity. Among them, 1048 participants underwent the positron emission tomography-computed tomography (PET-CT) and plasma biomarker test. Grip strength and gait were combined into a score indicating physical function. Multiple linear regression models and logistic regression models were mainly used to conduct the analysis. There was a significant positive correlation between physical function and cognitive function (R = 0.48, p < 0.001), independent of sex, age, apolipoprotein E-ε4 genotype, and disease stages (p < 0.001). Physical function was effective in distinguishing individuals with cognitive impairment from those without (AUC = 0.835). Physical function was negatively associated with brain Aβ deposition (p = 0.008) and brain Aβ had an intermediary effect (p < 0.01) on the association between physical function and cognition in women. This association was mainly evident in the lateral parietal, lateral temporal, posterior cingulate, frontal, occipital, and precuneus regions. Physical function was negatively associated with plasma neurofilament light-chain (Nfl) level (p < 0.001). Physical function is strongly associated with cognitive function in the Chinese elderly, and brain Aβ deposition partly mediates the linkage in women. Plasma Nfl can be used as a potential target for exercise intervention in cognitive function. Improving physical function will contribute to the alleviation of cognition decline.

Unusual metastases to the breast from different extramammary malignancies: a multimodality imaging approach in a case series.

Extramammary metastases are uncommon and usually related to a poor prognosis, but the radiologist can suspect the diagnosis based on the patient's clinical history and specific imaging findings. Several imaging procedures may be used to evaluate breast metastases from different extramammary malignancies, including mammography, ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography-CT (PET-CT). The clinical and imaging presentation of these metastases is contingent upon how the illness spreads, however, they have the potential to resemble either benign or malignant breast tumors. Metastases that disseminate hematologically tend to appear as a single round or oval mass with circumscribed margins. Sonographically, they are usually hypoechoic, and with CT or MRI, they usually enhance. Lymphatic dissemination, for example, frequently reveals significant asymmetry with skin thickening and diffuse breast edema, which is compatible with an inflammatory breast carcinoma. Knowing the many types of cancers that have the potential to spread to the breast as well as being able to accurately diagnose them is crucial to prevent a needless mastectomy and provide guidance for subsequent treatment. The purpose of this article is to provide a better understanding of the imaging features and immunohistochemistry (IHC) of secondary tumors of the breast by presenting eight distinctive cases, which will enable radiologists to recognize this entity.

Hope and trust in diagnostic imaging contexts – Constituting technology and liminal patients

IntroductionThis study investigates patients’ experience of selected imaging examinations and how human experiences are transformed through technological mediation. MethodA qualitative study of patients' experiences during selected imaging examinations, centering on human-technology relations, was conducted.Data was gathered in two Danish hospitals, through semi-structured interviews and participant observations. The study included fifteen diagnostic imaging examination cases, distributed over three Computed Tomography (CT)-guided lung biopsy interventions, seven conventional CT examinations, and five Positron Emission Tomography CT examinations. The participating patients were undergoing investigation for cancer within Fast Track Cancer Referral Programs (FTCRP).The study has a philosophical approach to practice grounded in Postphenomenology and draws on anthropological studies of healthcare practice as its theoretical and analytical framework. ResultsDiagnostic imaging technologies were found to have existential implications creating hope and trust in patients. Patients demonstrated technological readiness, in their willingness to comply with examination criteria and the professional's instructions. The patient's primary concern was achieving a good examination result, for which they were prepared to push themselves beyond their usual limits.Participating in diagnostic imaging examinations may be viewed as a life crisis ritual, wherein patients are constituted as liminal beings, existing between healthy and sick. ConclusionsThe existential implications of an imaging examination were clear in terms of hope and trust. Hope is related to life and death in two temporal perspectives: A future hope of surviving cancer and a present hope of being cancer-free. Hope was linked to avoiding despair and rested on trusting oneself to technology, thus, forming a circle of interrelated concepts. Implications for practiceProfessionals need to recognize the patients’ liminal passings yet, unnoticed transformative and existential implications, to perform better patient-centered care.

Prospective comparison of 68Ga-DOTA-ibandronate and bone scans for detecting bone metastases in breast cancer.

68Ga labeled DOTA-Ibandronate (68Ga-DOTA-IBA) positron emission tomography/computed tomography (PET/CT), is a novel bone-targeting imaging tracer and promising diagnostic method for bone metastases detection. Therefore, this study aimed to compare 68Ga-DOTA-IBA PET/CT to the 99mTc-MDP whole-body bone scan (WBBS) for detecting bone metastases in breast cancer (BC). In this prospective study, 45 women with BC underwent imaging via 68Ga-DOTA-IBA PET/CT and 99mTc-MDP WBBS. Clinical and demographic information as well as BC imaging features were recorded. The two methods were compared in terms of their detection rate for bone metastases and the number of lesions. The 45 women were aged 53.5 ± 11.0 years. The bone metastases detection rate with 68Ga-DOTA-IBA PET/CT was 100% (45/45) and with 99mTc-MDP WBBS was 95.6% (43/45). A total of 546 bone metastases lesions were detected. The lesion detection rate using 68Ga-DOTA-IBA PET/CT was 100% (546/546) and using 99mTc-MDP WBBS was 67.8% (370/546). More lesions were found at each site via 68Ga-DOTA-IBA than via 99mTc-MDP WBBS. 68Ga-DOTA-IBA PET/CT is a more sensitive method than 99mTc-MDP WBBS for assessing bone metastases in BC and may therefore represent a useful imaging technique for bone metastases, while offering a visual basis for 177Lu-DOTA-IBA diagnosis and therapy response assessments for BC. Further validation using a broader study cohort is warranted to confirm these findings. https://www.chictr.org.cn/showproj.html?proj=170163, identifier ChiCTR2200064487.

Objective Ischemia, Subjective Angina, and Psychological Distress in Angina With No Obstructive Coronary Disease.

Angina with no obstructive coronary disease (ANOCA) and ischemia with no obstructive coronary disease, prevalent yet underrecognized conditions, mostly affect women. Previous studies rarely distinguished between them. We aimed to compare the prevalence of objective ischemia through various examinations in women with ANOCA and assess the impact of objective and subjective ischemia on their mental health. A total of 84 eligible women with ANOCA and 42 controls underwent mental stress, pharmacological stress, exercise stress, and Holter testing. Objective evidence of myocardial ischemia was assessed by positron emission tomography-computed tomography and ECG, and subjective symptoms were graded using the Canadian Cardiovascular Society scale (CCS). Psychological assessments were conducted using 6 scales. Among 84 women with ANOCA, 37 (44%) received a diagnosis of ischemia with no obstructive coronary disease following mental stress testing, 20 (28.6%) through pharmacological stress testing, 14 (21.2%) via exercise stress testing, and 24 (32.9%) from Holter. Mental stress-induced myocardial ischemia was more prevalent (P<0.05). Among 54 patients with ANOCA who completed all tests, 30% showed no ischemia, and only 1 (1.9%) showed ischemia in all tests. In addition, patients with ANOCA had higher psychological scores than controls (P<0.01). No significant differences was observed in psychological scores between ANOCA with positive and negative ischemia test results (P>0.05). However, ANOCA with milder angina (CCS I) exhibited higher scores across the Hospital Anxiety and Depression Scale, State-Trait Anxiety Inventory, Perceived Stress Scale, and Posttraumatic Stress Disorder Checklist-Civilian Version and a higher prevalence of Type D personality traits (P<0.05). In patients with ANOCA, the positive rate of myocardial ischemia exhibits variability among several noninvasive tests. A worsened psychological state is more closely linked to milder angina symptoms than to ischemia performance, highlighting the importance of focusing on symptom management in their psychological care. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03982901.

Phosphoglyceride crystal deposition with suspected malignant ovarian tumor: a case report and literature review.

Phosphoglyceride crystal deposition disease is a rare condition occurring in soft tissues, resulting in scarring and affecting the bones, making preoperative differentiation from malignant tumors challenging. Here, we describe a case of phosphoglyceride crystal deposition disease initially suspected to be a malignant ovarian tumor before surgery. A 50-year-old woman with a history of three cesarean sections presented with lower abdominal pain. Transvaginal ultrasonography revealed a 54 × 58mm tumor in the lower right abdomen. Pelvic contrast-enhanced magnetic resonance imaging showed a thickened cystic wall with diffusion restriction, a low signal intensity region on T1-weighted images, and a slightly high signal intensity region on T2-weighted images. The tumor markers, cancer antigen 125 and carbohydrate antigen 19-9 levels, were within normal ranges; however, positron emitting tomography-computed tomography revealed fluorodeoxyglucose accumulation (SUVmax 31.28) in the tumor wall. Suspecting a malignant ovarian tumor, a laparoscopy was performed to observe the abdominal cavity. A 10cm white solid tumor was identified in the midline of the lower abdominal wall, leading to an open surgery recommendation. The tumor, adhering to the pubic bone, was excised. The tumor measured 9 × 7cm, with the cut surface showing a yellow brownish solid periphery and central region with liquefied degeneration. Histologically, radial basophilic deposits, dense infiltration of macrophages, multinucleated giant cells, and foam-like tissue spheres were observed. The central region exhibited cholesterol clefts, fibrin exudation, and necrosis, leading to a diagnosis of phosphoglyceride crystal deposition disease. This disease is rare, occurring in patients with atypical fluorodeoxyglucose accumulation on positron emission tomography-computed tomography or with a history of tissue damage, such as abdominal surgery.

Adversarial EM for variational deep learning: Application to semi-supervised image quality enhancement in low-dose PET and low-dose CT

In positron emission tomography (PET) and X-ray computed tomography (CT), reducing radiation dose can cause significant degradation in image quality. For image quality enhancement in low-dose PET and CT, we propose a novel theoretical adversarial and variational deep neural network (DNN) framework relying on expectation maximization (EM) based learning, termed adversarial EM (AdvEM). AdvEM proposes an encoder–decoder architecture with a multiscale latent space, and generalized-Gaussian models enabling datum-specific robust statistical modeling in latent space and image space. The model robustness is further enhanced by including adversarial learning in the training protocol. Unlike typical variational-DNN learning, AdvEM proposes latent-space sampling from the posterior distribution, and uses a Metropolis–Hastings scheme. Unlike existing schemes for PET or CT image enhancement which train using pairs of low-dose images with their corresponding normal-dose versions, we propose a semi-supervised AdvEM (ssAdvEM) framework that enables learning using a small number of normal-dose images. AdvEM and ssAdvEM enable per-pixel uncertainty estimates for their outputs. Empirical analyses on real-world PET and CT data involving many baselines, out-of-distribution data, and ablation studies show the benefits of the proposed framework.

Early prediction of microvascular invasion (MVI) occurrence in hepatocellular carcinoma (HCC) by 18F-FDG PET/CT and laboratory data

BackgroundHepatocellular carcinoma (HCC) is one of the deadliest malignant tumors in China. Microvascular invasion (MVI) often indicates poor prognosis and metastasis in HCC patients. 18F-FDG PET–CT is a new imaging method commonly used to screen for tumor occurrence and evaluate tumor stage.PurposeThis study attempted to predict the occurrence of MVI in early-stage HCC through 18F-FDG positron emission tomography (PET)/computed tomography (CT) imaging findings and laboratory data.Patients and methodsA total of 113 patients who met the inclusion criteria were divided into two groups based on postoperative pathology: the MVI-positive group and MVI-negative group. We retrospectively analyzed the imaging findings and laboratory data of 113 patients. Imaging findings included tumor size, tumor maximum standard uptake value (SUVmaxT), and normal liver maximum standard uptake value (SUVmaxL). The ratios of SUVmaxT to SUVmaxL (SUVmaxT/L) and an SUVmaxT/L > 2 were defined as active tumor metabolism. The tumor size was indicated by the maximum diameter of the tumor, and a diameter greater than 5 cm was defined as a mass lesion. The laboratory data included the alpha-fetoprotein (AFP) level and the HBeAg level. An AFP concentration > 20 ng/mL was defined as a high AFP level. A HBeAg concentration > 0.03 NCU/mL was defined as HB-positive.ResultsThe SUVmaxT/L (p = 0.003), AFP level (p = 0.008) and tumor size (p = 0.015) were significantly different between the two groups. Patients with active tumor metabolism, mass lesions and high AFP levels tended to be MVI positive. Binary logistic regression analysis verified that active tumor metabolism (OR = 4.124, 95% CI, 1.566–10.861; p = 0.004) and high AFP levels (OR = 2.702, 95% CI, 1.214–6.021; p = 0.015) were independent risk factors for MVI. The sensitivity of the combination of these two independent risk factors predicting HCC with MVI was 56.9% (29/51), the specificity was 83.9% (52/62) and the accuracy was 71.7% (81/113).ConclusionActive tumor metabolism and high AFP levels can predict the occurrence of MVI in HCC patients.

Prognostic Role of Pre- and Post-Treatment [18F]FDG PET/CT in Squamous Cell Carcinoma of the Oropharynx in Patients Treated with Chemotherapy and Radiotherapy.

The prognostic role of imaging with [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) in oropharynx cancer (OPC) has been demonstrated in the past. The aim of this study was to assess the prognostic impact of both baseline and post-treatment PET/CT in patients with OPC and treated with chemo- and/or radiotherapy. The PET/CT parameters of scans performed before and after therapy were collected and analyzed to find significant prognosticators for progression-free survival (PFS) and overall survival (OS). Human papillomavirus (HPV) infection's influence on the prognosis was also taken into account. A total of 66 patients were included in the study. The staging volumetric parameters of PET/CT were significant prognosticators for OS, while the same parameters were affordable predictors for PFS at the restaging evaluation. No significant correlations between HPV infection and PET/CT parameters were reported. The prognostic role of volumetric [18F]FDG PET/CT parameters in patients with OPC was reported.

The value of net influx constant based on FDG PET/CT dynamic imaging in the differential diagnosis of metastatic from non-metastatic lymph nodes in lung cancer.

This study aims to evaluate the value of the dynamic and static quantitative metabolic parameters derived from 18F-fluorodeoxyglucose (FDG)-positron emission tomography/CT (PET/CT) in the differential diagnosis of metastatic from non-metastatic lymph nodes (LNs) in lung cancer and to validate them based on the results of a previous study. One hundred and twenty-one patients with lung nodules or masses detected on chest CT scan underwent 18F-FDG PET/CT dynamic + static imaging with informed consent. A retrospective collection of 126 LNs in 37 patients with lung cancer was pathologically confirmed. Static image analysis parameters include LN-SUVmax and LN-SUVmax/primary tumor SUVmax (LN-SUVmax/PT-SUVmax). Dynamic metabolic parameters including the net influx rate (Ki) and the surrogate of perfusion (K1) and of each LN were obtained by applying the irreversible two-tissue compartment model using in-house Matlab software. Ki/K1 was then calculated as a separate marker. Based on the pathological findings, we divided into a metastatic group and a non-metastatic group. The χ2 test was used to evaluate the agreement of the individual and combined diagnosis of each metabolic parameter with the gold standard. The receiver-operating characteristic (ROC) analysis was performed for each parameter to determine the diagnostic efficacy in differentiating non-metastatic from metastatic LNs with high FDG-avid. P < 0.05 was considered statistically significant. Among the 126 FDG-avid LNs confirmed by pathology, 70 LNs were metastatic, and 56 LNs were non-metastatic. For ROC analysis, in separate assays, the dynamic metabolic parameter Ki [sensitivity (SEN) of 84.30%, specificity (SPE) of 94.60%, accuracy of 88.89%, and AUC of 0.895] had a better diagnostic value than the static metabolic parameter SUVmax (SEN of 82.90%, SPE of 62.50%, accuracy of 74.60%, and AUC of 0.727) in differentiating between metastatic from non-metastatic LNs groups, respectively. In the combined diagnosis group, the combined SUVmax + Ki diagnosis had a better diagnostic value in the differential diagnosis of metastatic from non-metastatic LNs, with SEN, SPE, accuracy, and AUC of 84.3%, 94.6%, 88.89%, and 0.907, respectively. When the cutoff value of Ki was 0.022ml/g/min, it had a high diagnostic value in the differential diagnosis between metastasis and non-metastasis in FDG-avid LNs of lung cancer, especially in improving the specificity. The combination of SUVmax and Ki is expected to be a reliable metabolic parameter for N-staging of lung cancer.