The Complementary Role of PET to Pathology in Differentiating the Primary Origin of a Malignant Skin Nodule from Liver or Lung.

Metastasis from unknown primary is always a challenge because finding the true primary tumor significantly affects subsequent management. We present a case of malignant abdominal wall nodule initially diagnosed as metastasis from hepatocellular carcinoma through excisional biopsy and immunohistochemical (IHC) staining. Dual-tracer positron emission tomography/computed tomography (PET/CT) with C-acetate and F-FDG, however, showed metabolic findings in favor of metastasis from lung origin, which was finally confirmed by ensuing a lung biopsy with additional IHC stains.

Diagnosis of Seronegative Rheumatoid Arthritis by Ga-FAPI PET/CT.

Early diagnosis of rheumatoid arthritis with the initiation of disease-modifying antirheumatic drugs is important to prevent future disability. Seronegative rheumatoid arthritis lacks the classical immunological markers, thus imposing clinical diagnostic difficulty. In this case, we reported  Ga-FAPI PET/CT findings of seronegative rheumatoid arthritis in a 60-year-old lady.

Clinical and neuroimaging markers of neurodegeneration in first-degree relatives of patients with REM sleep behavior disorder with and without isolated rapid eye movement sleep without atonia: A case-control clinical and dopamine PET study.

Objectives: The current study aimed to examine the neurodegenerative implication of isolated REM sleep without atonia (RSWA) among first-degree relatives of patients with REM sleep behaviour disorder (RBD).

Methods: This cross-sectional case-control study recruited three groups of subjects: First-degree relatives of RBD patients with isolated RSWA (n = 17), first-degree relatives of RBD patients without isolated RSWA (n = 18), and normal controls who did not have any RWSA and family history of RBD (n = 15). Prodromal Parkinson's Disease likelihood ratio by the updated MDS Research Criteria and striatal dopaminergic transmission function of the subjects as assessed by triple-tracer (18F-DOPA, 11C-Raclopride, and 18F-FDG) PET/CT scan were used as proxy markers of neurodegeneration.

Reliability of gradient-based segmentation for measuring metabolic parameters influenced by uptake time on 18F-PSMA-1007 PET/CT for prostate cancer.

Purpose: To determine an optimal setting for functional contouring and quantification of prostate cancer lesions with minimal variation by evaluating metabolic parameters on 18F-PSMA-1007 PET/CT measured by threshold-based and gradient-based methods under the influence of varying uptake time.

Methods And Materials: Dual time point PET/CT was chosen to mimic varying uptake time in clinical setting. Positive lesions of patients who presented with newly diagnosed disease or biochemical recurrence after total prostatectomy were reviewed retrospectively.

Lower Posterior Cingulate N-Acetylaspartate to Creatine Level in Early Detection of Biologically Defined Alzheimer's Disease.

Alzheimer’s disease (AD) was recently defined as a biological construct to reflect neuropathologic status, and both abnormal amyloid and tau are required for a diagnosis of AD. We aimed to determine the proton MR spectroscopic (1H-MRS) patterns of the posterior cingulate in biologically defined AD. A total of 68 participants were included in this study, comprising 37 controls, 16 early AD, and 15 late AD, who were classified according to their amyloid and tau status and presence of hippocampal atrophy.

Case series: MRD negativity assessment using C-Acetate PET with 3-weekly daratumumab-based quadruplet induction in newly diagnosed multiple myeloma.

Complete response (CR) is an important favorable factor for survival in multiple myeloma (MM). However, CR patients continue to relapse, especially in the presence of minimal residual disease (MRD). Bone marrow (BM) MRD is predictive of progression-free survival (PFS) in MM.

MRI-based Alzheimer's disease-resemblance atrophy index in the detection of preclinical and prodromal Alzheimer's disease.

Alzheimer's Disease-resemblance atrophy index (AD-RAI) is an MRI-based machine learning derived biomarker that was developed to reflect the characteristic brain atrophy associated with AD. Recent study showed that AD-RAI (≥0.5) had the best performance in predicting conversion from mild cognitive impairment (MCI) to dementia and from cognitively unimpaired (CU) to MCI.

Quantitative Susceptibility Mapping of the Hippocampal Fimbria in Alzheimer's Disease.

Background: The fimbria is a small white matter bundle that connects the hippocampus to the rest of the brain. Damage to the hippocampal gray matter is established in Alzheimer's disease (AD), but the hippocampal fimbrial status in the pathogenesis of AD is unclear. AD-related demyelination and iron deposition alter the diamagnetic and paramagnetic composition of tissues, which can be measured by quantitative susceptibility mapping (QSM).

Current status of PSMA PET imaging in prostate cancer.

The past decade has witnessed the rising popularity and acceptance of molecular definitions on disease management. Prostate-specific membrane antigen (PSMA), in light of its molecular nature and cytokinetic properties, has rapidly become the target for development of a variety of functional tracers for PET/CT evaluation of prostate cancer. The most commonly used PSMA-binding analog is Ga-labeled PSMA-11, which is now widely applied in both research and clinical settings.

The role of dopamine dysregulation and evidence for the transdiagnostic nature of elevated dopamine synthesis in psychosis: a positron emission tomography (PET) study comparing schizophrenia, delusional disorder, and other psychotic disorders.

There have been few studies performed to examine the pathophysiological differences between different types of psychosis, such as between delusional disorder (DD) and schizophrenia (SZ). Notably, despite the different clinical characteristics of DD and schizophrenia (SZ), antipsychotics are deemed equally effective pharmaceutical treatments for both conditions. In this context, dopamine dysregulation may be transdiagnostic of the pathophysiology of psychotic disorders such as DD and SZ.

Significant Value of C-Acetate and F-Fluorodeoxyglucose PET/Computed Tomography on Y Microsphere Radioembolization for Hepatocellular Carcinoma.

Pretreatment dual-tracer (F-fluorodeoxyglucose and C-acetate) PET/computed tomography (CT) has potential to predict treatment response for Y microsphere radioembolization (RE) in patients with inoperable hepatocellular carcinoma (HCC). Patients with C-acetate-avid HCC have a better response to Y microsphere RE, and possibly better survival. Pretreatment dual-tracer PET/CT has a significant theranostic value on Y microsphere RE in determining target tumor dose for HCCs with different cellular differentiation, metabolic tumor volume, and functioning liver volume, and can be used to prescribe individual injected activity of Y microspheres.

Dual-Tracer PET/CT Differentiates 2 Types of Primary Cancers and Metastases in a Patient With Crossed Fused Renal Ectopia.

A patient was found incidentally on dual-tracer (C-acetate [ACT] and F-FDG [FDG]) PET/CT for having crossed fused renal ectopia and 2 types of malignant tumors, colonic carcinoma and renal cell carcinoma (RCC), each having its own characteristic tracer avidity. Multiple liver metastases were also mutually exclusive, with a purely ACT-avid group of metastatic lesions from RCC and another FDG-avid group from colonic carcinoma. Bone and lung metastases, however, could not be readily distinguishable in terms of primary origins.

Nosocomial transmission of hepatitis C virus in a liver transplant center in Hong Kong: implication of reusable blood collection tube holder as the vehicle for transmission.

Background: A liver transplant recipient developed hospital-acquired symptomatic hepatitis C virus (HCV) genotype 6a infection 14 months post transplant.

Objective: Standard outbreak investigation.

Methods: Patient chart review, interviews of patients and staff, observational study of patient care practices, environmental surveillance, blood collection simulation experiments, and phylogenetic study of HCV strains using partial envelope gene sequences (E1-E2) of HCV genotype 6a strains from the suspected source patient, the environment, and the index patient were performed.

Radioembolization with Y glass microspheres for hepatocellular carcinoma: significance of pretreatment C-acetate and F-FDG PET/CT and posttreatment Y PET/CT in individualized dose prescription.

Purpose: The aim of this study was to establish an algorithm for the prescription of Y glass microsphere radioembolization (Y-GMRE) of HCC in individual patients based on the relationship between tumour dose (TD) and response validated by Y PET/CT dosimetry and dual-tracer PET/CT metabolic parameters.

Methods: The study group comprised 62 HCC patients prospectively recruited for Y-GMRE who underwent pretreatment dual-tracer (C-acetate and F-FDG) PET/CT as surrogate markers of HCC cellular differentiation. Pretreatment tumour-to-nontumour ratio on Tc-MAA SPECT/CT (T/NT) was correlated with posttreatment Y PET/CT T/NT after quantification validation.

68Ga-DOTATOC and 68Ga-PSMA PET/CT Unmasked a Case of Prostate Cancer With Neuroendocrine Differentiation.

A bedridden 90-year-old man with fever and elevated prostate-specific antigen (PSA) (49 ng/mL) was referred for differentiation between infection and tumor. F-FDG PET/CT was negative for infection, but Ga-PSMA PET/CT showed multiple lesions in prostate gland with infiltration to bladder wall and seminal vesicle, consistent with locally advanced prostate cancer. The lesion with the highest Ga-PSMA uptake was strongly avid for Ga-DOTATOC, suggesting neuroendocrine tumor differentiation.

Reduced striatal dopamine transmission in REM sleep behavior disorder comorbid with depression.

Objective: To investigate dopamine transmission in patients with comorbid REM sleep behavior disorder (RBD) and major depressive disorder (MDD).

Methods: This is a case-control study including 11 medicated patients with comorbid RBD and MDD (mean age 47.5 ± 8.

11C-acetate PET/CT for metabolic characterization of multiple myeloma: a comparative study with 18F-FDG PET/CT.

Unlabelled: We prospectively compared (11)C-acetate with (18)F-FDG in a PET/CT evaluation of multiple myeloma (MM), specifically on diagnostic accuracy, identification of high-risk patients, and monitoring of treatment response.

Methods: Dual-tracer PET/CT was performed on 35 pathologically and clinically confirmed and untreated patients (26 with symptomatic MM, 5 with smoldering MM, and 4 with monoclonal gammopathy of unknown significance) and 20 individuals with normal marrow.

Results: (11)C-acetate showed significant incremental value over (18)F-FDG (84.

(11)C-acetate PET/CT in a case of recurrent hemangiopericytoma.

Intracranial hemangiopericytoma (IHPC) is a rare tumor representing less than 1% of all CNS tumors and is often indistinguishable from meningioma on structural imaging alone. Unlike meningioma, IHPC is an aggressive tumor with the propensity for early locoregional recurrence and distant metastases. Hence, its management strategies differ greatly from that of meningioma.

(11)C-acetate as a new biomarker for PET/CT in patients with multiple myeloma: initial staging and postinduction response assessment.

Purpose: We investigated the potential value of (11)C-acetate (ACT) PET/CT in characterizing multiple myeloma (MM) compared with (18)F-FDG PET/CT. Bone marrow histological and whole-body (WB) MRI findings served as the reference standards.

Methods: In this prospective study, 15 untreated MM patients (10 men and 5 women, age range 48-69 years) underwent dual-tracer (11)C-ACT and (18)F-FDG PET/CT and WB MRI for pretreatment staging, and 13 of them had repeated examinations after induction therapy.

11C-acetate and 18F-FDG PET/CT for clinical staging and selection of patients with hepatocellular carcinoma for liver transplantation on the basis of Milan criteria: surgeon's perspective.

Unlabelled: The success of liver transplantation (LT) for hepatocellular carcinoma (HCC) is enhanced by careful patient selection on the basis of the Milan criteria. The criteria are traditionally assessed by contrast CT, which is known to be affected by structural or architectural changes in cirrhotic livers. We aimed to compare dual-tracer ((11)C-acetate and (18)F-FDG) PET/CT with contrast CT for patient selection on the basis of the Milan criteria.

Dual-tracer PET/CT in renal angiomyolipoma and subtypes of renal cell carcinoma.

Unlabelled: We studied the metabolic characteristics of RCC subtypes and angiomyolipoma with 18F-FDG and 11C-acetate PET/CT.

Methods: Fifty-eight patients with both baseline CT and dual-tracer PET/CT were recruited: 10 angiomyolipoma (16 lesions) and 48 RCC (50 lesions). Each lesion was assessed for SUVmax ratio (lesion-to-normal kidney) on 11C-acetate/18F-FDG PET and attenuation density on CT.

Predictors for cognitive decline in patients with confluent white matter hyperintensities.

Background: Although patients harboring confluent white matter hyperintensities (WMH) are at high risk of cognitive decline, this risk varies among individuals. We investigated the predictors for cognitive decline in stroke patients with confluent WMH.

Methods: We followed up 100 stroke patients with confluent WMH who were participants of the VITAmins TO Prevent Stroke study for 2 years.

[18F]fluoroacetate positron emission tomography for hepatocellular carcinoma and metastases: an alternative tracer for [11C]acetate?

[11C]Acetate (ACT) positron emission tomography/computed tomography (PET/CT) is useful in the detection of hepatocellular carcinoma (HCC). This study aimed to evaluate whether [18F]fluoroacetate (FAC) could be an alternative analogue of [11C]ACT for the diagnosis of HCC. [18F]FAC was synthesized using the precursor t-butyl 2-(methanesulfonyloxy)ethanoate.