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. MATERIALS AND METHODS: Multiple MRI brain scan contrasts from the OASIS-3 dataset were defaced with PyFaceWipe and PyDeface and manually assessed for brain voxel preservation, remnant facial features and effect on automated face detection. Original and PyFaceWipe-defaced data from locally acquired T1w structural scans underwent volumetry with FastSurfer and brain atlas generation with ANTS. RESULTS: 214 MRI scans of several contrasts from OASIS-3 were successfully processed with both PyFaceWipe and PyDeface. PyFaceWipe maintained complete brain voxel preservation in all tested contrasts except ASL (45%) and DWI (90%), and PyDeface in all tested contrasts except ASL (95%), BOLD (25%), DWI (40%) and T2* (25%). Manual review of PyFaceWipe showed no failures of facial feature removal. Pinna removal was less successful (6% of T1 scans showed residual complete pinna). PyDeface achieved 5.1% failure rate. Automated detection found no faces in PyFaceWipe-defaced scans, 19 faces in PyDeface scans compared with 78 from the 224 original scans. Brain atlas generation showed no significant difference between atlases created from original and defaced data in both young adulthood and late elderly cohorts. Structural volumetry dice scores were ≥ 0.98 for all structures except for grey matter which had 0.93. PyFaceWipe output was identical across the tested operating systems. CONCLUSION: PyFaceWipe is a promising multiplatform defacing tool, demonstrating excellent brain voxel preservation and competitive defacing in multiple MRI contrasts, performing favourably against PyDeface. ASL, BOLD, DWI and T2* scans did not produce recognisable 3D renders and hence should not require defacing. Structural volumetry dice scores (≥ 0.98) were higher than previously published FreeSurfer results, except for grey matter which were comparable. The effect is measurable and care should be exercised during studies. ANTS atlas creation showed no significant effect from PyFaceWipe defacing.

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.This comprehensive review explores the MRI patterns associated with central neurotoxicities induced by various chemotherapeutic agents. Our objective is to provide radiologists and clinicians with illustrative diagrams that offer a structured approach to diagnosing these conditions. By enhancing the understanding of these distinctive MRI patterns, we aim to facilitate accurate and timely diagnosis, ultimately improving patient care in the context of evolving cancer treatments.Critical relevance statementThis article describes the essential role of MRI in identifying distinct patterns of chemotherapy-induced central neurotoxicity, enabling early diagnosis and improved patient care within the field of clinical radiology.Key points• Chemotherapy-induced neurotoxicity is a growing concern for cancer patients, and MRI is a key tool in diagnosis.• This review highlights distinctive MRI patterns associated with various chemotherapy-induced neurotoxicities.• Understanding these patterns improves patient care, ensuring timely intervention and accurate diagnosis in the complex world of cancer treatment.

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. Additionally, a systematic review of COVID-19 mRNA vaccine-related myocarditis, conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) principles, is presented. Healthcare professionals should maintain a clinical suspicion for COVID-19 mRNA vaccine-related myocarditis when encountering patients with confirmed myocarditis who have received recent COVID-19 mRNA vaccination, after ruling out other potential causes. The diagnosis of acute myocarditis primarily relies on adherence to the Lake Louise Criteria (LLC) for cardiac magnetic resonance (CMR). Nevertheless, specific CMR features or distinctive patterns indicative of COVID-19 mRNA vaccine-related myocarditis are currently undefined. Among patients with vaccine-related myocarditis, common CMR findings encompass subepicardial late gadolinium enhancement and T2-based myocardial edema, although these findings lack specificity and may resemble other medical conditions. Supportive care involving a short-term regimen of NSAIDs, colchicine, and steroids represents the cornerstone of treatment for this variant of myocarditis, which tends to be self-limiting with favorable short-term prognoses. Timely diagnosis is paramount for optimizing patient care.

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. Following surgical debulking, histology examination revealed a tumor of stromal origin with myxoid and ossifying components and pleomorphic features. Overall findings were suggestive of a malignant OFMT. The patient underwent postoperative adjuvant radiotherapy. However, the first follow-up MRI study at 8 months showed residual tumor, which also demonstrated avid tracer uptake on technetium-99m scintigraphy and PET-CT scans. The second MRI follow-up about 9 months later showed several metastatic foci along the craniospinal axis. Despite subsequent resection of the spinal metastasis, the patient eventually died of sepsis about 21 months after the initial tumor diagnosis. CONCLUSIONS We presented a case of extradural spinal malignant OFMT and highlighted the difficulty distinguishing this rare primary tumor from spinal metastases. In this case, MRI signal intensities and identifying intratumoral bone formation, combined with histopathology following surgical resection, confirmed the diagnosis. This case has also shown the importance of follow-up by a multidisciplinary team to monitor for the recurrence of primary OFMT.

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. CASE REPORT A 52-year-old woman with history of CS presented with pituitary adenoma and multiple meningiomata. After surgical resection, there was recurrence of the pituitary tumor. Partial resection of the recurrent pituitary tumor revealed an adenoma. Radiotherapy was administered due to the histopathological aggressive features of the resected pituitary tumor and growth of the residual pituitary tumor on follow-up. Although the pituitary tumor shrank after radiotherapy, there was development of multiple new intracranial extra-axial lesions, including meningiomata. Resection of a rapidly growing extra-axial tumor in the parietal convexity region was performed. Given the similar histopathological features of the convexity tumor with the prior pituitary specimen, the diagnosis of pituitary carcinoma was established. A subsequent MRI scan showed metastatic deposits along the spine. The patient's condition deteriorated and she died shortly after the last surgery. CONCLUSIONS To the best of our knowledge, there is no prior report of pituitary carcinoma in a patient with CS in the literature. Pituitary carcinomas frequently spread within the craniospinal axis, in addition to hematogenous dissemination. Given the high risks of developing malignant tumors in patients with CS, multidisciplinary management including diagnostic imaging and close surveillance are of paramount importance in patient management.

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. The clinical and imaging features of these high-flow vascular malformations and their treatment options are discussed and we provide a review of the literature. CASE REPORT A 40-year-old woman presented with a large 6.4×6.0×13.0 cm high-flow Schobinger stage II high-flow AVM of the parotid gland and auricle. Diagnostic imaging included magnetic resonance imaging (MRI) and conventional catheter angiogram, which defined the vascular anatomy and flow characteristics of the AVM. She was treated with preoperative endovascular embolization followed by surgical excision and free-tissue transfer reconstruction on the next day. The results were excellent, with no recurrence over 3.5 years of follow-up. CONCLUSIONS This is the second case reported in the literature of high-flow AVM concurrently involving the parotid gland and auricle, treated with perioperative embolization followed by surgical excision and grafting. Management of AVMs requires a multidisciplinary team approach and understanding of the natural history of the lesion. Although total surgical resection is the criterion standard for these AVMs, endovascular embolization is an alternative treatment that can be used as an adjunct to surgery. Furthermore, perioperative embolization can decrease the vascularity of the lesion and effectively reduce blood loss during AVM surgery.

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). The imaging and histopathological characteristics, as well as the treatment strategy of this vascular lesion, are highlighted along with a comprehensive review of the literature. CASE REPORT A 38-year-old woman presented with progressively worsening low back pain that radiated to both legs. Neurological examination revealed a weakness of the left leg without sensory loss. Magnetic resonance imaging (MRI) demonstrated an epidural tumor at L1-L2 level, making an obtuse angle with the cerebrospinal fluid (CSF) on sagittal T2-weighted images. The patient underwent a complete tumor resection without complications or recurrence. The histology revealed a capillary hemangioma. CONCLUSIONS SECH is exceedingly rare, with only 22 cases in the reported literature. Females are more commonly affected than males, and the thoracic spine is more commonly involved than the lumbar spine. SECH often mimics other epidural and IDEM lesions, leading to misdiagnosis. MRI is useful to differentiate SECH from lesions in the various spinal compartments; additionally, MRI is essential for preoperative planning and patient surveillance. Preoperative embolization is an option given the high vascularity of SECH. Surgery is the mainstay treatment, with a good prognosis, in most cases without recurrence.

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. In this review, we present a collection of classic MRI signs, ranging from neoplastic to non-neoplastic lesions, within the spinal cord. The Differential Diagnosis (DD) of intramedullary lesions can be narrowed down by careful analysis of the classic signs and patterns of involvement in the spinal cord. Furthermore, the signs are illustrated memorably with emphasis on the pathophysiology, mimics, and pitfalls. Artificial Intelligence (AI) algorithms, particularly deep learning, have made remarkable progress in image recognition tasks. The classic signs and related illustrations can enhance a pattern recognition approach in diagnostic radiology. Deep learning can potentially be designed to distinguish neoplastic from non-neoplastic processes by pattern recognition of the classic MRI signs.

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. We hereby derive an explanation for the variable imaging features of white epidermoids and propose an imaging approach to distinguish white epidermoids from black epidermoids. METHODS: We conducted a review of white epidermoids in PubMed and Cochrane databases based on PRISMA principles. Qualitative analysis was carried out on the selected cases of white epidermoids, focusing on pathogenesis, imaging features, treatment and prognosis. RESULTS: Out of 1281 studies, we identified 26 full-text articles, comprising 68 patients with white epidermoid cysts, including an illustrative case example from our institution. White epidermoids have completely different MRI signals compared to the classical black epidermoids. Owing to tumour adhesions to the surrounding structures, there is a higher risk of leakage of white epidermoid content during surgery, causing severe aseptic meningitis. We demonstrate an approach to explain the variable imaging features of white epidermoids based on their cyst content - white epidermoids with low T2 signals content often contain high protein levels and viscosity, while those with high T2 signals contain blood products. CONCLUSION: During preoperative planning, it is important to identify white epidermoids. Extensive neurovascular damage should be avoided during surgery given the favourable prognosis of the epidermoids regardless of the extent of tumour resection.

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. This study highlights the imaging characteristics, histopathological and molecular data, treatment strategies and post-treatment changes of primary intraventricular tumors. Molecular-based diagnosis can not only aid in patient stratification and personalized treatment, but it can also provide prognostic and predictive value independent of WHO classification.

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. This is largely attributed to the lack of literature on the imaging features of scalp epithelioid sarcoma. In this report, we highlight the role of multimodality imaging in the diagnosis of primary scalp epithelioid sarcoma and review the epidemiology, imaging, treatment options, and prognosis of these malignant scalp tumors. Displaying a multilobulated morphology, heterogeneous enhancement, and restricted diffusion on MRI, these tumors typically show central degeneration with hemorrhage, necrosis, and calcification. Wide surgical resection and adjuvant radiotherapy are the mainstays of treatment for localized scalp tumors. Nevertheless, the prognosis of patients with distant metastases at diagnosis is extremely poor compared to those with local or regional diseases.

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. The "Bow-tie" and "laminar space" signs represent UCFJD on plain radiographs. The "reversed hamburger", "naked facet" and "headphones" signs represent cervical facet joint dislocations on axial cross-sectional imaging. Illustrating these signs in an engaging manner facilitates pattern-based recognition, which can benefit trainees and radiologists. Moreover, pattern-based recognition can be applied to machine learning.

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. Furthermore, imaging is important in (1) evaluating the extent of tumor invasion in the scalp, (2) staging the disease, (3) guiding surgical biopsy and/or resection of the tumor, (4) preoperative planning and post-treatment surveillance of scalp tumors. An interdisciplinary treatment approach is crucial for the management of scalp malignancies given their complex and aggressive nature. This review seeks to describe the unique clinical and imaging characteristics of various types of malignant scalp masses, as well as to review their current treatment strategies.

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. Transcatheter arterial embolization is a rare treatment option for DIHE associated with hemodynamic instability and only a handful of cases have been reported in the literature.

Extensive systemic metastases from primary central nervous system haemangiopericytoma.

Primary intracranial tumours rarely metastasise outside of the central nervous system (CNS). This report describes a rare case of recurrent meningeal haemangiopericytoma with extensive systemic metastases, which eventually resulted in a fatal outcome. We discuss some prevailing theories as to the rarity of extracranial metastases from primary CNS haemangiopericytoma, and elucidate the epidemiology, imaging features, differential diagnosis, treatment, and prognosis of this unusual but surprisingly aggressive meningeal tumour. Besides aggressive treatment for local tumour control, patients with primary CNS haemangiopericytoma require long-term post-treatment surveillance to detect systemic metastases.

Image-guided robotic neurosurgery--an in vitro and in vivo point accuracy evaluation experimental study.

BACKGROUND: We describe the development of a prototype neurosurgical robotic system called NISS. The aim is to implement a robotic system capable of achieving accurate registration of robotic coordinate systems based on CT images, so that it can be used in clinical application. This system has been refined with a better level of predictability, reliability, and robustness sufficient for animal trial evaluation in stereotactic biopsy of brain lesions. METHODS: Point accuracy evaluation of NISS began with an in vitro study. The in vitro robotic application accuracy result was 0.1 +/- 0.05 mm and absolute needle-to-target deviation was 0.3 +/- 0.2 mm. An in vivo experiment approach of using steel balls of 1.56-mm-diameter as targets inside the brain of an anaesthetized dog was used to evaluate the performance accuracy of NISS stereotactic probe placement. Five dogs underwent surgical insertion of steel balls into the brain, and the steel balls were served as targets to be reached by a core needle (1.56-mm-diameter). The experiment was carried out by precise manipulation of the needle to reach the steel ball using frameless stereotactic localization principles. RESULTS: A total of 9 needle results were collected from procedures involving 5 dogs. In the first 5 procedures on 3 dogs, the results were less than 1.9 mm, with an average of 1.3 +/- 0.5 mm. The remaining 4 procedures on 2 dogs yielded results of less than 0.7 mm, with an average of 0.3 +/- 0.2 mm. CONCLUSION: The in vitro and in vivo studies represent the first approach toward evaluating targeting accuracy of a robotic surgery system by using stereotactics biopsy application in a living subject.

Postoperative Imaging of Complications Following Cranial Implants.

A wide range of neurosurgical implants, cranioplasty materials and catheters have been developed to treat a variety of intracranial disorders. Interpretation of postoperative imaging can be challenging and confounded by postoperative changes and implant-related complications. Review of recent literature suggested that there is a paucity of data on postoperative cranial implant-related complications. If not addressed appropriately in a timely manner, these complications may cause a delay in the patient's treatment with subsequent prolongation of hospital stay. It is therefore paramount for clinicians and radiologists to be aware of the appearance of these implant-related complications on imaging during postoperative surveillance.

Carotid Mycotic Aneurysm associated with Persistent Primitive Hypoglossal Artery. Case Report and Literature Review.

Carotid mycotic aneurysm is extremely rare and even more unusual when it is associated with a persistent primitive hypoglossal artery. This artery is the second most common of the embryonic carotid-vertebrobasilar anastomoses. It originates from the cervical internal carotid artery and enters the cranium through a widened hypoglossal canal before anastomosing with the basilar artery. We report a case of an elderly man with a rare Salmonella-induced mycotic aneurysm associated with a persistent primitive hypoglossal artery. Surgical resection of the mycotic aneurysm was complicated by a posterior circulation stroke. To the best of our knowledge, there was no previous report of a carotid mycotic aneurysm associated with a persistent primitive hypoglossal artery thus far in the literature. Owing to the high mortality rate of the carotid mycotic aneurysm, it is imperative to be familiar with the vascular and imaging anatomy prior to surgery particularly in the presence of an embryonic carotid-vertebrobasilar anastomosis. In this report, we highlight the imaging characteristics and treatment options for this rare mycotic aneurysm together with a literature review.