Perineural tumour spread in head and neck cancer can be a challenging diagnosis for radiologists; head and neck anatomy is intimidating and perineural tumour spread can be subtle and difficult to detect. It results in significant morbidity for patients, can upstage disease and will frequently result in more prolonged treatment courses. This pictorial review provides a thorough examination of the imaging characteristics of perineural tumour spread in head and neck malignancy. It highlights key imaging features, from initial diagnosis to its post therapy appearance, emphasising the clinical relevance and role of imaging in post-therapy assessment. Multi-modality imaging examples are included with a focus on MRI and PET/CT. MRI features of perineural tumour spread include intermediate T2 signal expansion of a nerve, abnormal enhancement extending along a nerve, expansion of a skull or neural foramen and loss of normal fat planes surrounding nerve pathways. 18F-FDG PET/CT is a useful adjunct to MRI, perineural tumour spread results in abnormal FDG accumulation in a linear fashion anatomically spreading along a nerve pathway. Knowledge of these features and useful check areas will ensure that radiologists can be confident both making the diagnosis and in re-assessment post therapy.

Pulmonary Pleomorphic Carcinomas (PPCs) represent a rare and aggressive subtype of Non-Small Cell Lung Cancer (NSCLC) that can only be definitively diagnosed on a surgical specimen. This study utilised PET-CT to evaluate radiological characteristics of PPCs. This study retrospectively evaluated the radiological characteristics of PCCs diagnosed in St James’s Hospital Dublin between 2012-2023. Computed Tomography (CT) and Positron Emission Tomography (FDG-PET) imaging features (size, location, density, shape, invasion, and growth kinetics) and standard uptake value for each lesion were evaluated. 39 PCCs were identified with a mean age of 66.5 years (range: 49-82 years). FDG-PET was performed in all 39 cases. Tumours demonstrated a high FDG uptake at baseline with a mean (SUV) of 12.6 (range: 1.4 - 36.9). A second interval PET-CT on average 3.3 months after the first in 3 cases demonstrated over 120% increase in SUV. The mean tumour size was 4.3 cm (range: 1.0 - 14.5 cm). Tumours developed rapid interval growth, reaching a mean maximum diameter of 6.6 cm (53.4%) within a mean of 2.1 months. Tumours were predominantly located in the upper lobe (71.8 %) and displayed necrotic features in 53.8 % of cases. 82.1% of tumours invaded the mediastinum. This study describes the largest cohort of Pulmonary Pleomorphic Carcinoma in the literature. Tumours demonstrate a high SUV on baseline imaging and demonstrate rapid growth on interval imaging and central necrosis. Please click on the 'PDF' for the full abstract!

A 77-year-old male smoker was scheduled to undergo computed tomography (CT)–guided percutaneous transthoracic lung biopsy of a fluorodeoxyglucose-avid cystic mass in the anterior segment of the right upper lobe (Fig 1a). The wall of the mass was irregular, with a maximal wall thickness of 5 mm.

Background Little is known regarding cognitive outcomes following treatment with endovascular clot retrieval (ECR) and intravenous tissue plasminogen activator (t-PA). We aimed to determine if there were any differences on a measure of cognitive screening between patients treated with ECR, t-PA, and those who were managed conservatively. Methods The medical records of ischaemic stroke patients admitted to Monash Medical Centre between January 2019 and December 2019 were retrospectively reviewed. Information extracted from medical records included age, sex, National Institutes of Health Stroke Scale at presentation, location of occlusion, treatment type, medical history, and cognitive screening performance measured by the Montreal Cognitive Assessment (MoCA). Results Eighty-two patients met the inclusion criteria (mean age = 66.5 ± 13.9; 49 male, 33 female). Patients treated with ECR performed significantly better on the MoCA (n = 36, 24.1 ± 4.3) compared to those who were managed conservatively (n = 26, 20.7 ± 5.5). Performance for patients treated with t-PA (n = 20, 23.9 ± 3.5) fell between the ECR and conservative management groups, but they did not significantly differ from either. Conclusion Our retrospective chart review found that ischaemic stroke patients treated with ECR appear to perform better on cognitive screening compared to patients who are managed conservatively. We also found that patients treated with ECR and t-PA appear to have similar cognitive screening performances in the acute stages following ischaemic stroke, although this finding is likely to have been impacted by group differences in stroke characteristics and may reflect the possibility that the ECR group performed better than expected based on their stroke severity.

Tuberous sclerosis (TS) is a monogenic disorder which causes disabling neurological symptoms. Similarly, multiple sclerosis (MS) may result in disability, but in contrast, is diagnosed without genetic testing. Clinicians are advised to exercise caution in diagnosing MS in the presence of a pre-existing genetic disorder, as it may be a potential 'red flag'. A dual diagnosis of MS and TS has not previously been reported in the literature. We provide two cases of known cases of TS who presented with new neurological symptoms and associated physical signs compatible with a dual diagnosis of TS/MS.

Abstract Extensive research over the past twenty years explains and documents different approaches to and examples of social enterprise across the world. One line of research analyses the institutional contexts – considering economic development, governance, culture, and civil society - in order to explain different national approaches to social enterprise. Simultaneously, researchers have focussed on organisational level features to create typologies of social enterprises. This paper synthesises that research to create an embedded model of types, which sit within and are infl uenced by institutional contextual factors. The model is tested in the case of the Republic of Ireland, through desk research and empirical observation. A set of 57 organisations provides qualitative data for a narrative account of four types of social enterprise. Contributions include a new model of institutionally embedded social enterprise types which conceptualises and highlights the importance of historical contexts in applying typologies.

Background: Left ventricular assist devices (LVADs) are artificial pumps used in end-stage heart failure to support the circulatory system. These cardiac assist devices work in parallel to the heart, diverting blood from the left ventricle through an outflow graft and into the ascending aorta. LVADs have allowed patients with end-stage heart failure to live longer and with improved quality of life compared to best medical therapy alone. However, they are associated with significant risks related to both thrombosis and bleeding in this medically complex patient population. As LVADs continue to be used more widely, stroke neurologists need to become familiar with the unique physical exam and vascular imaging findings associated with this population. Summary: Reported rates of LVAD-associated stroke at 2 years post-implantation range from 10 to 30%, which is significantly higher than in age-matched controls. There are approximately equal rates of ischemic and hemorrhagic strokes, and rates are highest during the peri-implantation period and in the first year of therapy. Risk factors associated with ischemic and hemorrhagic stroke in this cohort can be grouped into treatment-related factors, including specific devices and antithrombotic/anticoagulation strategy, and patient-related factors. Evidence for reperfusion therapy for acute stroke in this population is limited. Intravenous tissue plasminogen activator (IV-tPA) is often contraindicated as events may occur in the perioperative setting, or in the context of therapeutic anticoagulation. Endovascular therapy with successful recanalization is reported, but there is little experience documented in the published literature. Key messages: LVAD use is increasingly common. Given the high associated risks of stroke, neurologists will need to become increasingly familiar with an approach to assessment and therapy for LVAD patients with cerebrovascular issues.

Background: Iron-overload cardiomyopathy initially manifests with diastolic dysfunction and can progress to dilated cardiomyopathy if untreated. Previous studies have shown that patients with primary and secondary hemochromatosis can have subclinical left ventricle dysfunction with abnormalities on strain imaging. This study aimed to evaluate the relationship between cardiac T2* values and myocardial-wall strain in patients with hereditary hemochromatosis (HH) at the time of diagnosis and after a course of venesection treatment. Materials and Methods: Baseline cardiac magnetic resonance (CMR) at 3 T was performed in 19 patients with newly diagnosed HH with elevated serum ferritin levels and repeated after a course of treatment with venesection. Quantitative T2* mapping and strain analysis were performed offline using dedicated relaxometry fitting and feature-tracking software. Results: The majority (84%) of patients had normal baseline myocardial T2* values (mean 19.3 ms, range 8.9 to 31.2 ms), which improved significantly after venesection (mean 24.1 ms, range 11 to 38.1 ms) (P=0.021). Mean global radial strain significantly improved from 25.0 (range: 15.6 to 32.9) to 28.3 (range: 19.8 to 35.8) (P=0.001) and mean global circumferential strain improved, decreasing from −15.7 (range: −11.1 to −19.2) to −17.1 (range: −13.0 to −20.1) (P=0.001). Conclusion: Patients with HH may have normal T2* values in the presence of subclinical left ventricle dysfunction, which can be detected by abnormal radial and circumferential strain. As strain imaging improves following venesection in HH, it may serve as a useful biomarker to guide treatment.

Purpose: Cavitary lung lesions often pose a diagnostic challenge, and tissue sampling can be required to obtain a confident diagnosis. Many authors contend that a computed tomography–guided percutaneous transthoracic lung biopsy (PTLB) of a cavitary lung lesion places a patient at higher risk for systemic air embolism (SAE) compared with biopsy of a noncavitary lesion. Materials and Methods: We reviewed the literature for studies of SAE complicating PTLB. We searched English-language articles indexed through PubMed, Embase, and Ovid Medline and included articles published up to March 31, 2020 Results: We identified 10 case reports of SAE complicating PTLB, and 3 case-cohort studies comparing cavitary and noncavitary lesion biopsy. Among the case-cohort studies reviewed, 4 SAE occurred among 145 biopsies of cavitary lesions (2.7%), and 65 SAE occurred among 3050 biopsies of noncavitary lesions (2.1%). The pooled odds ratio of PTLB complicating SAE of cavitary lesions compared with noncavitary lesions was 1.29 (95% confidence interval: 0.47-3.60). No deaths following SAE after computed tomography–guided PTLB of cavitary lesions were reported in recent literature. Conclusions: On the basis of available evidence, air embolism rates are similar for PTLB of cavitary and noncavitary lesions. Additional research and registry studies are necessary to better understand this topic.

Chronic lung allograft dysfunction (CLAD) is the most common cause of mortality in lung transplant recipients after the 1st year of transplantation. CLAD has traditionally been classified into two distinct obstructive and restrictive forms: bronchiolitis obliterans syndrome and restrictive allograft syndrome. However, CLAD may manifest with a spectrum of imaging and pathologic findings and a combination of obstructive and restrictive physiologic abnormalities. Although the initial CT manifestations of CLAD may be nonspecific, the progression of findings at follow-up should signal the possibility of CLAD and may be present on imaging studies prior to the development of functional abnormalities of the lung allograft. This review encompasses the evolution of CT findings in CLAD, with emphasis on the underlying pathogenesis and pathologic condition, to enhance understanding of imaging findings. The purpose of this article is to familiarize the radiologist with the initial and follow-up CT findings of the obstructive, restrictive, and mixed forms of CLAD, for which early diagnosis and treatment may result in improved survival. Supplemental material is available for this article. © RSNA, 2021.

Purpose: Primary lung cancers associated with cystic airspaces are increasingly being recognized; however, there is a paucity of data on their natural history. We aimed to evaluate the prevalence, pathologic, and imaging characteristics of cystic lung cancer in a regional thoracic surgery center with a focus on the evolution of computed tomography morphology over time. Materials and Methods: Consecutive patients referred for potential surgical management of primary lung cancer between January 2016 and December 2018 were included. Clinical, imaging, and pathologic data were collected at the time of diagnosis and at the time of the oldest computed tomography showing the target lesion. Descriptive analysis was carried out. Results: A total of 441 cancers in 431 patients (185 males, 246 females), median age 69.6 years (interquartile range: 62.6 to 75.3 y), were assessed. Overall, 41/441 (9.3%) primary lung cancers were cystic at the time of diagnosis. The remaining showed solid (67%), part-solid (22%), and ground-glass (2%) morphologies. Histopathology of the cystic lung cancers at diagnosis included 31/41 (76%) adenocarcinomas, 8/41 (20%) squamous cell carcinomas, 1/41 (2%) adenosquamous carcinoma, and 1/41 (2%) unspecified non-small cell lung carcinoma. Overall, 8/34 (24%) cystic cancers at the time of diagnosis developed from different morphologic subtype precursor lesions, while 8/34 (24%) cystic precursor lesions also transitioned into part-solid or solid cancers at the time of diagnosis. Conclusions: This study demonstrates that cystic airspaces within lung cancers are not uncommon, and may be seen transiently as cancers evolve. Increased awareness of the spectrum of cystic lung cancer morphology is important to improve diagnostic accuracy and lung cancer management.

A healthy 54-year-old woman developed spontaneous acute onset of sharp left-sided neck and facial pain and odynophagia following a brief flu-like illness. CT angiography revealed eccentric perivascular infiltration at the left carotid bifurcation (figure 1) with corresponding enhancement on MRI (figure 2). She was empirically treated with prednisone and had clinical and imaging improvement at follow-up.

Dual-energy computed tomography (CT) is a promising tool with increasing availability and multiple emerging and established clinical applications in neuroradiology. With its ability to allow characterization of materials based on their differential attenuation when imaged at two different energy levels, dual-energy CT can help identify the composition of brain, neck, and spinal components. Virtual monoenergetic imaging allows a range of simulated single energy-level reconstructions to be created with postprocessing. Low-energy reconstructions can aid identification of edema, ischemia, and subtle lesions due to increased soft tissue contrast as well as increasing contrast-to-noise ratios on angiographic imaging. Higher energy reconstructions can reduce image artifact from dental amalgam, aneurysm clips and coils, spinal hardware, dense contrast, and dense bones. Differentiating iodine from hemorrhage may help guide management of patients after thrombectomy and aid diagnosis of enhancing tumors within parenchymal hemorrhages. Iodine quantification may predict hematoma expansion in aneurysmal bleeds and outcomes in traumatic brain injury. Calcium and bone subtraction can be used to distinguish hemorrhage from brain parenchymal mineralization as well as improving visualization of extra-axial lesions and vessels adjacent to dense plaque or skull. This article reviews the basics of dual-energy CT and highlights many of its clinical applications in the evaluation of acute neurological presentations.

PURPOSE:To assess the interobserver variability between chest radiologists in the interpretation of the Radiological Society of North America (RSNA) expert consensus statement reporting guidelines in patients with suspected coronavirus disease 2019 (COVID-19) pneumonia in a setting with limited reverse transcription polymerase chain reaction testing availability. METHODS:Chest computed tomography (CT) studies in 303 consecutive patients with suspected COVID-19 were reviewed by 3 fellowship-trained chest radiologists. Cases were assigned an impression of typical, indeterminate, atypical, or negative for COVID-19 pneumonia according to the RSNA expert consensus statement reporting guidelines, and interobserver analysis was performed. Objective CT features associated with COVID-19 pneumonia and distribution of findings were recorded. RESULTS:The Fleiss kappa for all observers was almost perfect for typical (0.815), atypical (0.806), and negative (0.962) COVID-19 appearances (P < .0001) and substantial (0.636) for indeterminate COVID-19 appearance (P < .0001). Using Cramer V analysis, there were very strong correlations between all radiologists' interpretations, statistically significant for all (typical, indeterminate, atypical, and negative) COVID-19 appearances (P < .001). Objective CT imaging findings were recorded in similar percentages of typical cases by all observers. CONCLUSION:The RSNA expert consensus statement on reporting chest CT findings related to COVID-19 demonstrates substantial to almost perfect interobserver agreement among chest radiologists in a relatively large cohort of patients with clinically suspected COVID-19. It therefore serves as a reliable reference framework for radiologists to accurately communicate their level of suspicion based on the presence of evidence-based objective findings.

Hereditary haemochromatosis is often not diagnosed until adulthood. Iron overload cardiomyopathy initially results in diastolic dysfunction and can result in arrhythmias and irreversible cardiac failure if untreated. The aim of this study was to investigate whether patients with newly diagnosed hereditary haemochromatosis without signs of heart failure exhibit subclinical alterations of cardiac function and to determine if cardiac function improved after 1 year of venesection. Baseline echocardiography was performed on 25 patients with newly diagnosed hereditary haemochromatosis with elevated serum ferritin levels. The test was repeated after 1 year of treatment with venesection. Tissue Doppler imaging (TDI) and deformation (strain) imaging using speckle tracking were performed. Left atrial force was measured according to the Newtonian principle, in which force (dynes) = mass × acceleration. Left atrial force was calculated by the Manning method expressed as ρ × 0.53 × mitral annular orifice area × (peak A velocity)2. Radial strain showed a significant improvement after 1 year of venesection (increase from 38.8 to 52.6). The LAF showed a significant decrease after 1 year of venesection (median decrease = 0.6 (IQR 0, 1.60), p = 0.0004). Iso-volumetric relaxation time (IVRT) decreased significantly in patients after 1 year of venesection (decrease from 107.4 ± 16.2 to 97.68 ± 15.4 ms, p (0.0187)). Among all measurements, radial strain, IVRT and left atrial force were shown to significantly improve following a 1-year course of venesection, suggesting that these parameters could be used to identify subclinical cardiac dysfunction in patients with iron overload secondary to hereditary haemochromatosis and to guide intensification of venesection therapy.

Purpose: The RSNA expert consensus statement and CO-RADS reporting system assist radiologists in describing lung imaging findings in a standardized manner in patients under investigation for COVID-19 pneumonia and provide clarity in communication with other healthcare providers. We aim to compare diagnostic performance and inter-/intra-observer among chest radiologists in the interpretation of RSNA and CO-RADS reporting systems and assess clinician preference. Methods: Chest CT scans of 279 patients with suspected COVID-19 who underwent RT-PCR testing were retrospectively and independently examined by 3 chest radiologists who assigned interpretation according to the RSNA and CO-RADS reporting systems. Inter-/intra-observer analysis was performed. Diagnostic accuracy of both reporting systems was calculated. 60 clinicians participated in a survey to assess end-user preference of the reporting systems. Results: Both systems demonstrated almost perfect inter-observer agreement (Fleiss kappa 0.871, P < 0.0001 for RSNA; 0.876, P < 0.0001 for CO-RADS impressions). Intra-observer agreement between the 2 scoring systems using the equivalent categories was almost perfect (Fleiss kappa 0.90-0.92, P < 0.001). Positive predictive values were high, 0.798-0.818 for RSNA and 0.891-0.903 CO-RADS. Negative predictive value were similar, 0.573-0.585 for RSNA and 0.573-0.58 for CO-RADS. Specificity differed between the 2 systems, 68-73% for CO-RADS and 52-58% for RSNA with superior specificity of CO-RADS. Of 60 survey participants, the majority preferred the RSNA reporting system rather than CO-RADS for all options provided (66.7-76.7%; P < 0.05). Conclusions: RSNA and CO-RADS reporting systems are consistent and reproducible with near perfect inter-/intra-observer agreement and excellent positive predictive value. End-users preferred the reporting language in the RSNA system.

In this paper, we propose a CT imaging algorithm for patients presenting with suspected acute stroke that incorporates automated CT perfusion (CTP) imaging. The algorithm details evaluation of the non-contrast CT (NCCT) for hemorrhage and acute ischemia, calculation of ASPECTS, with performance and interpretation of CTP if appropriate. In particular, we consider the key steps in expeditious interpretation of non-contrast CT and CT angiography in the context of suspected acute ischemic stroke. Given the recent expansion of the “imaging based” treatment window for thrombectomy from 6 to 24 h in the 2018 American Heart Association stroke guidelines, we consider the key criteria in the decision to perform CT perfusion and the patient cohorts in which this might be most helpful. We also describe how imaging findings might be incorporated into the treatment paradigm for suspected with acute ischemic stroke and we allude to some of the most frequently encountered pitfalls associated with CTP which we think will be particularly helpful for radiologists and stroke physicians who are considering adding CT perfusion to their work-up for acute stroke.

Rapid overcorrection of chronic hyponatremia can lead to osmotic demyelination syndrome or central pontine myelinolysis (CPM), a diagnosis often triggered by observing the characteristics of neurological abnormalities developed as a result of CPM. However, anyone with chronic hyponatremia and overcorrection of serum sodium is at risk of physiological CPM despite the lack of clinical symptoms. We report an adult patient who presented as post-op delirium, had incidental finding of CPM by magnetic resonance imaging (MRI) of the head after a liver transplant. Despite his non-typical presentation, the patient had the typical risk factors of CPM such as chronic hyponatremia, rapid overcorrection of serum sodium and cirrhosis undergoing a transplant. As hyponatremia and neurological disorder such encephalopathy simultaneously affect patients with cirrhosis, CPM may be more common than once thought in the chronic liver disease population and inappropriate hyponatremia management has important medical consequences that can go unnoticed.

A 51-year-old, otherwise well woman, presented with progressive severe dyspnoea. CT pulmonary angiogram (CTPA) demonstrated a large filling defect within the right main pulmonary artery with evidence of right heart strain. She was anticoagulated and discharged home; however, was readmitted with progression of symptoms and hypotension within 1month. Repeat CTPA demonstrated progression of the filling defect. Formal surgical thrombectomy was performed with removal of an unusual cream-coloured, rubber-like material. Histological analysis revealed intravenous leiomyomatosis (IVL). IVL is a rare benign neoplasm, characterised by smooth muscle cell proliferation in vascular structures that can act aggressively. This case describes the workup, recognition and management of IVL.