Enlarging and shrinking focal perivascular spaces.

BACKGROUND AND PURPOSE: Perivascular spaces (PVS) are interstitial fluid-filled spaces surrounding blood vessels traversing the deep gray nuclei and white matter of the brain. These are commonly encountered on CT and MR imaging and are generally asymptomatic and of no clinical significance. However, occasional changes in the size of focal PVS, for example, when enlarging, may mimic pathologies including neoplasms and infections, hence potentially confounding radiological interpretation. Given these potential diagnostic issues, we sought to better characterize common clinical and imaging features of focal PVS demonstrating size fluctuations. MATERIALS AND METHODS: Upon institutional approval, we retrospectively identified 4 cases demonstrating PVS with size changes at our institution. To supplement our cases, we also performed a literature review, which identified an additional 14 cases. Their clinical and imaging data were analyzed to identify characteristic features. RESULTS: Of the 18 total cases (including the 4 institutional cases), 10 cases increased and 8 decreased in size. These focal PVS ranged from 0.4-4.5 cm in size. Whereas a decrease in size did not represent a diagnostic issue, focal increase in size of PVS led to concerning differential diagnoses in at least 30% of the radiology reports. These enlarging PVS were most found in the basal ganglia and temporal lobe, and in patients with previous brain radiation treatment. CONCLUSION: Focal size change of PVS can occur, especially years after brain radiation treatment. Being cognizant of this benign finding is important to consider in the differential diagnosis to avoid undue patient anxiety or unnecessary medical intervention.

Diagnostic Imaging for Retinoblastoma Cancer Staging: Guide for Providing Essential Insights for Ophthalmologists and Oncologists.

Retinoblastoma is the most common cause of all intraocular pediatric malignancies. It is caused by the loss of RB1 tumor suppressor gene function, although some tumors occur due to MYCN oncogene amplification with normal RB1 genes. Nearly half of all retinoblastomas occur due to a hereditary germline RB1 pathogenic variant, most of which manifest with bilateral tumors. This germline RB1 mutation also predisposes to intracranial midline embryonal tumors. Accurate staging of retinoblastoma is crucial in providing optimal vision-, eye-, and life-saving treatment. The AJCC Cancer Staging Manual has undergone significant changes, resulting in a universally accepted system with a multidisciplinary approach for managing retinoblastoma. The authors discuss the role of MRI and other diagnostic imaging techniques in the pretreatment assessment and staging of retinoblastoma. A thorough overview of the prevailing imaging standards and evidence-based perspectives on the benefits and drawbacks of these techniques is provided. Published under a CC BY 4.0 license. Test Your Knowledge questions for this article are available in the supplemental material.

Assessing the Emergence and Evolution of Artificial Intelligence and Machine Learning Research in Neuroradiology.

BACKGROUND AND PURPOSE: Interest in artificial intelligence (AI) and machine learning (ML) has been growing in neuroradiology, but there is limited knowledge on how this interest has manifested into research and specifically, its qualities and characteristics. This study aims to characterize the emergence and evolution of AI/ML articles within neuroradiology and provide a comprehensive overview of the trends, challenges, and future directions of the field. MATERIALS AND METHODS: We performed a bibliometric analysis of the American Journal of Neuroradiology (AJNR): the journal was queried for original research articles published since inception (Jan. 1, 1980) to Dec. 3, 2022 that contained any of the following key terms: "machine learning", "artificial intelligence", "radiomics", "deep learning", "neural network", "generative adversarial network", "object detection", or "natural language processing". Articles were screened by two independent reviewers, and categorized into Statistical Modelling (Type 1), AI/ML Development (Type 2), both representing developmental research work but without a direct clinical integration, or End-user Application (Type 3) which is the closest surrogate of potential AI/ML integration into day-to-day practice. To better understand the limiting factors to Type 3 articles being published, we analyzed Type 2 articles as they should represent the precursor work leading to Type 3. RESULTS: A total of 182 articles were identified with 79% being non-integration focused (Type 1 n = 53, Type 2 n = 90) and 21% (n = 39) being Type 3. The total number of articles published grew roughly five-fold in the last five years, with the non-integration focused articles mainly driving this growth. Additionally, a minority of Type 2 articles addressed bias (22%) and explainability (16%). These articles were primarily led by radiologists (63%), with most of them (60%) having additional postgraduate degrees. CONCLUSIONS: AI/ML publications have been rapidly increasing in neuroradiology with only a minority of this growth being attributable to end-user application. Areas identified for improvement include enhancing the quality of Type 2 articles, namely external validation, and addressing both bias and explainability. These results ultimately provide authors, editors, clinicians, and policymakers important insights to promote a shift towards integrating practical AI/ML solutions in neuroradiology. ABBREVIATIONS: AI = artificial intelligence; ML = machine learning.

Percutaneous treatment of stone containing calyceal diverticula: Strategies and outcomes from a University teaching hospital in a developing country.

INTRODUCTION: There is a dearth of research available on the outcomes, complications, and recurrence rates of the modalities employed in treatment of diverticula after stone clearance by PCNL. We present our experience of various approaches employed in our institute for treatment of caliceal diverticulum after stone clearance by PCNL. We aimed to review the outcomes, complications, and recurrence rates of these procedures which can provide valuable insights into the effectiveness of these techniques in the treatment of stone containing caliceal diverticulum. METHODS: A retrospective analysis of a prospectively maintained database of patients diagnosed with caliceal diverticular stone was conducted. The primary outcome was the stone-free rate (SFR) at the time of hospital discharge, determined by a combined nephroscopic/fluoroscopic assessment, and the obliteration of the diverticular sac. Secondary outcomes included the evaluation of operative time, duration of hospital stay and postoperative complications. RESULTS: A total of 53 patients were evaluated. The mean diverticulum size was 23.2 mm, most common location was the superior calyx (30 (56.7%)). Group 1 (diverticular neck treatment + DJ stent) included 27 patients, group 2 (diverticular wall fulguration + PCN) included 18 patients and group 3 (PCN alone) included 8 patients. Mean operating time was highest in group 1 (80 min). Stone clearance was 100% in group 1, 91% in group 2 and 88% in group 3. Obliteration of caliceal diverticulum was highest in group 1 (90%). Mean duration of hospital stay was lowest in group 1 (3.2 days). Overall complications were lowest in group 2 (3/18). CONCLUSION: PCNL followed by combination of diverticular wall fulguration and PCN or treatment of diverticular neck and DJ stenting is safe and effective in causing diverticular obliteration. Placement of nephrostomy tube alone was not found to be effective in causing diverticular obliteration in our study.

Safety of Magnetic Resonance Imaging in Pregnancy.

Magnetic resonance imaging is being increasingly used to diagnose and follow up a variety of medical conditions in pregnancy, both for maternal and fetal indications. However, limited data regarding its safe use in pregnancy may be a source of anxiety and avoidance for both patients and their healthcare providers. In this review, we critically discuss the main safety concerns of Magnetic Resonance Imaging (MRI) in pregnancy including energy deposition, acoustic noise, and use of contrast agents, supported by data from animal and human studies. Use of maternal sedatives and concerns related to occupational exposure in pregnant personnel are also addressed. Exposure to gadolinium-based contrast agents and sedation for MRI during pregnancy should be avoided whenever feasible.

Uncovering the Uncommon: Institutional Insights Into the Clinical and Epidemiological Characteristics of Rarer Forms of Bladder Cancer Beyond Transitional Cell Carcinoma.

Introduction Non-transitional cell carcinomas of the bladder (NTCCB) represent a significant clinical challenge due to their rarity, heterogeneity, and poor prognosis. Despite their poor prognosis, the treatment of NTCCB has historically been based on the same principles used for transitional cell carcinomas (TCCs). Our study focuses on the management of non-transitional cell carcinomas and aims to identify areas where treatment outcomes can be improved based on our institutional experience. Materials and methods A retrospective analysis of patients with NTCCB who presented at Kasturba Hospital Manipal was conducted between 2012 to 2021. Patient data were collected, and demographic characteristics, presenting symptoms, history of other primary malignancies, comorbidities, location of the tumour, stage at presentation, histopathological subtype, site of systemic metastasis, and primary treatment given were analyzed descriptively. Median overall survival was determined by calculating the time from the initial diagnosis to the date of death. Results Among 31 patients with NTCCB, 15 (48%) presented with metastatic disease, five (16%) with locally advanced disease, and 11 (36%) with localized disease. The most common histopathological subtypes were squamous cell carcinoma and adenocarcinoma, as noted in 14 (45.2%) and 13 (41.9%) patients, respectively, followed by neuroendocrine tumours in two (6.5%), extra-adrenal phaeochromocytoma in one (3.3%), and sarcomatoid carcinoma in one (3.3%) patient, respectively. The lung was the most frequent site of systemic metastasis as noted in six (40%) patients, followed by the liver and skeletal system in three (20%) patients each, peritoneum in two (13.3%), cerebral cortex in one (6.7%), and non-regional lymph nodes in one (6.7%) patient. The primary treatment given included palliative chemotherapy in 14 (45.2%) patients, radical cystectomy with ileal conduit in 10 (32.3%), neoadjuvant chemotherapy only in four (12.9%), partial cystectomy in one (3.2%), pelvic exenteration with ileal conduit in one (3.2%), and peritoneal debulking with palliative chemotherapy in one (3.2%) patient. The overall median survival was 15 months, with a one-year survival rate of 67.4%. Conclusion NTCCB exhibits aggressive clinical behaviour and presents with nonspecific clinical features in the early stages, often leading to late diagnosis and an advanced tumour stage at presentation. Multi-institutional studies with larger patient cohorts are needed to recommend best clinical practices for early detection and optimal treatment strategies to improve patient survival.

Comparing Tubeless and Tubed Approaches in Percutaneous Nephrolithotomy for Moderate Renal Calculi: Outcomes on Safety, Efficacy, Pain Management, Recovery Time, and Cost-Effectiveness.

Introduction This study focuses on investigating the effect of routine nephrostomy tube placement in patients with moderate renal calculi of size 2.5 cm or less who undergo uncomplicated percutaneous nephrolithotomy (PCNL) procedures. Previous studies have not specified whether only uncomplicated cases were included in the analysis, which may affect the results. This study aims to provide a clearer understanding of the effect of routine nephrostomy tube placement on blood loss in a more homogeneous patient population. Materials and methods A prospective randomized controlled trial (RCT) was conducted at our department over 18 months, dividing 60 patients with a single renal or upper ureteric calculus of size ≤2.5 cm into two groups: 30 patients in each group (group 1: tubed PCNL, group 2: tubeless PCNL). The primary outcome was the drop in perioperative hemoglobin level and the number of packed cell transfusions necessary. The secondary outcome included the mean pain score, analgesic requirement, length of hospital stay, time to return to normal activities, and the total cost of the procedure. Results The two groups were comparable in age, gender, comorbidities, and stone size. The postoperative hemoglobin level was significantly lower in the tubeless PCNL group (9.56 ± 2.13 gm/dL) compared to the tube PCNL group (11.32 ± 2.35 gm/dL) (p = 0.0037), and two patients in the tubeless group required blood transfusion. The duration of surgery, pain scores, and analgesic requirement were comparable between the two groups. The total procedure cost was significantly lower in the tubeless group (p = 0.0019), and the duration of hospital stay and time to return to daily activities were significantly shorter in the tubeless group (p < 0.0001). Conclusions Tubeless PCNL is a safe and effective alternative to conventional tube PCNL, with the advantages of shorter hospital stay, faster recovery, and lower procedure costs. Tube PCNL is associated with less blood loss and the need for transfusions. Patient preferences and bleeding risk should be considered when choosing between the two procedures.

Venous outflow stenting for symptomatic developmental venous anomaly.

Developmental venous anomaly (DVA) is one of the commonest vascular malformations in the brain but rarely symptomatic. Various pathomechanisms such as mechanical compression, increased in-flow into DVA or outflow obstruction have been described as causative factors in symptomatic DVAs. We report a unique case of a pontomedullary DVA with venous outflow obstruction causing progressive neurological worsening in a young adult despite anticoagulation, who was treated with a novel approach of venous outlet stenting of the collector vein with favorable outcome. In carefully selected cases, this endovascular treatment can be an effective and safe alternative when other measures fail.

T1 hyperintensity in the spinal cord: A diagnostic marker of amyotrophic lateral sclerosis?

Amyotrophic Lateral Sclerosis (ALS) is a rare, devastating motor neuron disease characterized by the degeneration of upper and lower motor neurons causing muscular weakness, paralysis, and eventual death. MRI plays a supportive role in the diagnosis; its primary role is to exclude other clinical mimics. Some of the imaging features associated with ALS include hypointense signal along the motor cortices on susceptibility or T2*-weighted imaging and hyperintensity along the corticospinal tracts (CST) within the cerebral hemispheres, brainstem, and spinal cord on the T2 weighted imaging. In this report, we discuss the value of T1 hyperintensity along the CST, especially in the spinal cord.

Practice enhancements with FastStroke ColorViz analysis in acute ischemic stroke.

In acute ischemic stroke (AIS), large vessel occlusion (LVO) and the status of pial collaterals are important factors in decision-making for further treatment such as endovascular therapy. Multiphasic CT Angiogram (mCTA) is the mainstay of AIS imaging, allowing detection of LVO, evaluation of intracranial arterial dynamics, and quantification of pial collaterals. However, thorough mCTA evaluation entails scrutiny of multiple image datasets, individually and then simultaneously, which can be time-consuming, causing a potential delay in treatment. ColorViz (FastStroke, GE Healthcare, Milwaukee, Wisconsin) is a novel CT application which combines mCTA information into a single color-coded dataset for quick, unequivocal evaluation of pial collaterals. In our practice, ColorViz is both time-saving and increases the diagnostic accuracy of LVO and pial collaterals as well as medium vessel, multivessel and posterior circulation occlusions. In this article, we discuss the practical aspects of ColorViz in patients presenting with AIS.

Detecting the Uncommon Imaging Manifestations of Posterior Reversible Encephalopathy Syndrome (PRES) in Adults: a Comprehensive Illustrated Guide for the Trainee Radiologist.

Posterior reversible encephalopathy syndrome (PRES) has traditionally been described as a reversible leukoencephalopathy with a distinct pattern of posteriorly distributed vasogenic oedema involving the subcortical regions of parietal and occipital lobes. PRES commonly occurs in the setting of hypertensive emergencies, pre-eclampsia/eclampsia, impaired renal function, and immunosuppressive therapy. The various clinical presentations of PRES include encephalopathy, seizures, headache, visual, and focal neurological deficits. As knowledge of this entity grows, the range of clinical, and radiological features is seen to be much broader than originally described. The brain oedema may not always be posteriorly distributed and the syndrome may not be uniformly reversible. Of special note are some uncommon imaging features (unilateral cerebral involvement, and isolated posterior fossa involvement) and also some uncommon complications (haemorrhage, cytotoxic oedema, and vasoconstriction). These red herrings may lead to potential diagnostic challenges and pitfalls especially for trainee radiologists, who often read these scans in an emergency setting. Early and accurate diagnosis is crucial for prompt optimum management, thereby avoiding residual morbidity. This review article focusses on the atypical radiological features of PRES in adults with extensive case-based imaging examples. A brief description of the pathophysiology, clinical, and classic radiological features of PRES has also been included. A tabulated summary of potential mimics with diagnostic pearls is provided to highlight pertinent take home points and to serve as an easy guide for day-to-day clinical practice.

Rhino-orbito-cerebral Mucormycosis: Pictorial Review.

Mucormycosis (MCR) is a fulminant, potentially lethal, opportunistic fungal infection. Diabetes, immunocompromised states and elevated serum iron levels are the most important risk factors for contracting MCR infection. Recently, MCR co-infections have been observed in patients with COVID-19 disease owing to a complex interplay of metabolic factors and corticosteroid therapy. Rhino-orbito-cerebral mucormycosis (ROCM) is the most common clinical form of MCR infection and refers to infection of the nasal cavities, paranasal sinuses, neck spaces, orbits and intracranial structures. Sinonasal inoculation is typically the primary site of infection; the necrotising and angioinvasive properties of the fungus facilitate its spread into adjacent structures. In this review, we discuss the pertinent mycology and risk factors of MCR infection. The review also aims to acquaint the reader with the cross-sectional imaging appearances of ROCM and its complications. All the cases discussed in this pictorial essay are microbiologically and/or histopathologically proven cases of ROCM with concomitant COVID-19 infection.

An assessment of the reported impact of the COVID-19 pandemic on leprosy services using an online survey of practitioners in leprosy referral centres.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has led to governments implementing a variety of public health measures to control transmission and has affected health services. Leprosy is a communicable neglected tropical disease caused by Mycobacterium leprae and is an important health problem in low- and middle-income countries. The natural history of leprosy means that affected individuals need long-term follow-up. The measures recommended to reduce transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can create barriers to health services. We evaluated the impact of the COVID-19 epidemic response on leprosy services and disease management. METHODS: We conducted a cross-sectional online survey with healthcare professionals in leprosy referral centres. RESULTS: Eighty percent of leprosy diagnostic services were reduced. All respondents reported that multidrug therapy (MDT) was available but two reported a reduced stock. Clinicians used alternative strategies such as telephone consultations to maintain contact with patients. However, patients were not able to travel to the referral centres. DISCUSSION: This study highlights the effects of the initial phase of the SARS-CoV-2 pandemic on leprosy services in a range of leprosy-endemic countries. Many services remained open, providing leprosy diagnosis, MDT and leprosy reaction medications. Centres developed innovative measures to counter the negative impacts of the COVID-19 pandemic.

Pearls and Pitfalls in the Magnetic Resonance Diagnosis of Dural Sinus Thrombosis: A Comprehensive Guide for the Trainee Radiologist.

Dural sinus thrombosis (DST) is a potentially fatal neurological condition that can be reversed with early diagnosis and prompt treatment. Non-enhanced CT scan is often the first imaging investigation in patients presenting with acute neurological symptoms; however, its poor sensitivity in detecting DST is a major drawback. Magnetic resonance (MR) imaging offers multiple advantages such as excellent contrast resolution and unenhanced venography possibilities, making it the mainstay in the non-invasive diagnosis of DST. However, physiological variations, evolution of thrombi, and incorrect selection/application of MR techniques can lead to false positive and false negative interpretations impacting patient management and outcome. This article discusses the MR techniques useful to diagnose DST and describes pitfalls, with troubleshooting methods, to ensure an accurate diagnosis. We have used multiple diagrammatic illustrations and MR images to highlight pertinent take-home points and to serve as an easy guide for day-to-day clinical practice.