Leptomeningeal Masses or Masquerades: A Spectrum of Diseases with Leptomeningeal Enhancement and their Mimics.

Background: Leptomeningeal enhancement, visible on MRI, can indicate a variety of diseases, both neoplastic and non-neoplastic.

Objective: This comprehensive pictorial review aims to equip radiologists and trainees with a thorough understanding of the diverse imaging presentations of leptomeningeal disease.

Methods: Drawing from a retrospective analysis of MRI scans conducted between 1 January 2008 and 30 September 2022, at two tertiary teaching hospitals in Singapore, this review covers a wide range of conditions.

PyFaceWipe: a new defacing tool for almost any MRI contrast.

Rationale And Objectives: Defacing research MRI brain scans is often a mandatory step. With current defacing software, there are issues with Windows compatibility and researcher doubt regarding the adequacy of preservation of brain voxels in non-T1w scans. To address this, we developed PyFaceWipe, a multiplatform software for multiple MRI contrasts, which was evaluated based on its anonymisation ability and effect on downstream processing.

MRI characteristics of chemotherapy-related central neurotoxicity: a pictorial review.

The relentless advancement of chemotherapeutic agents has enhanced survival rates among cancer patients. However, this success comes with an increased prevalence of chemotherapy-induced neurotoxicity, which often mimics the symptoms of metastatic disease or paraneoplastic syndromes and poses a diagnostic challenge for clinicians. Imaging, particularly MRI, plays a pivotal role in unraveling this conundrum.

COVID-19 mRNA vaccine-related myocarditis: A PRISMA systematic review, imaging approach and differential diagnoses.

We present a case involving a young individual who developed acute myocarditis on the fourth day following administration of a COVID-19 mRNA vaccine. The patient's condition was managed conservatively, resulting in a favorable outcome. This paper extensively discusses the pathogenesis, clinical manifestations, imaging characteristics of COVID-19 mRNA vaccine-related myocarditis and includes a comprehensive review of pertinent literature.

A Case of an 82-Year-Old Man with a Spinal Extradural Malignant Ossifying Fibromyxoid Tumor.

BACKGROUND Ossifying fibromyxoid tumor (OFMT) is a rare mesenchymal tumor predominantly involving the subcutaneous tissues or skeletal muscles in the proximal extremities, typically in middle-aged men. OFMT in the spine is extremely rare, with only 3 previously reported cases in the literature. CASE REPORT Here, we present a rare case of an 82-year-old man presenting with paresthesia of both arms and weakness of both legs, who underwent magnetic resonance imaging (MRI) of the spine, which showed an aggressive extradural tumor.

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.

Intracranial "white" epidermoid tumours - An imaging approach and systematic review.

Introduction: Intracranial epidermoid cysts are rare congenital inclusion cysts that can be divided into the classical "black epidermoid" and the exceedingly rare "white epidermoid". White epidermoids are often misdiagnosed because they have different imaging features compared to black epidermoids. There is a paucity of imaging review on white epidermoids.

Lumbar Spinal Epidural Capillary Hemangioma: A Case Report and Literature Review.

BACKGROUND Capillary hemangiomas are often seen on the skin of young individuals and are rarely found in the spine. These vascular lesions can arise from any spinal compartment, although they are more commonly found in the intradural extramedullary (IDEM) than the epidural location. We present a unique case of a woman with a histologically proven spinal epidural capillary hemangioma (SECH).

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.

Primary Epithelioid Sarcoma Manifesting as a Fungating Scalp Mass - Imaging Features and Treatment Options. A Case Report and Literature Review.

Primary epithelioid sarcoma is an extremely rare malignancy of the scalp. To date, less than a dozen such cases have been reported in the literature. The diagnosis often is a challenge to both radiologists and clinicians.

Management of an Extensive Intraparotid and Auricular Arteriovenous Malformation.

BACKGROUND Extracranial arteriovenous malformations (AVMs) of the parotid gland and auricle are rarely encountered. Management of these AVMs depends on the Schobinger stage and their flow characteristics. We present a rare case of an AVM involving the parotid and auricle concurrently.

Pituitary Carcinoma in a Patient with Cowden Syndrome.

BACKGROUND Pituitary carcinomas are rare tumors that are histologically indistinguishable from pituitary adenoma. This report describes an extremely rare case of pituitary carcinoma in a patient with clinically diagnosed Cowden syndrome (CS). CS is a rare multisystemic hereditary disease with increase risks of cancer and benign overgrowth of different types of tissues.

Distinguishing Intramedullary Spinal Cord Neoplasms from Non-Neoplastic Conditions by Analyzing the Classic Signs on MRI in the Era of AI.

Intramedullary lesions can be challenging to diagnose, given the wide range of possible pathologies. Each lesion has unique clinical and imaging features, which are best evaluated using magnetic resonance imaging. Radiological imaging is unique with rich, descriptive patterns and classic signs-which are often metaphorical.

Primary intraventricular tumors - Imaging characteristics, post-treatment changes and relapses.

Primary intraventricular neoplasms are rare tumors that originate from the ependymal or subependymal, septum pellucidum, choroid plexus and the supporting arachnoid tissue. Knowledge of the common locations of these tumors within the ventricular system, together with key imaging characteristics and presentation age, can significantly narrow the differential diagnosis. In 2016, the WHO reorganized the classification of several primary CNS tumors by combining histopathological and molecular data.

Life-threatening bleeding from dissecting Intramural Hematoma of Esophagus (IHE) treated by trans arterial embolization.

Dissecting intramural hematoma of esophagus (DIHE) is an uncommon entity, characterized by accumulation of blood within the esophageal wall and usually managed conservatively. Only in rare circumstances, DIHE is associated with massive life-threatening hemorrhage requiring emergency treatment. We present a case of DIHE associated with cardiovascular collapse and treated by transcatheter arterial embolization.

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.

Multimodality imaging and treatment strategy for malignant scalp neoplasms in adults.

Malignant scalp masses deserve much attention as they have the potential to destroy local structures, recur and metastasize to distant organs. Moreover, malignant scalp lesions are known to be more aggressive in behavior than their counterparts elsewhere in the body. Multimodality imaging is essential in narrowing the differential diagnoses of scalp masses, as well as in differentiating benign from malignant masses.

Radiological Signs in Traumatic Cervical Facet Joint Dislocations.

Unilateral cervical facet joint dislocation (UCFJD) is the most frequently missed cervical spine injury on plain radiographs. If left untreated, UCFJD can progress to bilateral cervical facet joint dislocation. Given the complexity of cervical facet joint dislocations, radiologists rely on metaphorical signs to identify them on radiographs.

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).