Longitudinal visibility of MRI findings in living victims of strangulation.

Initial experiences with magnetic resonance imaging (MRI) of living strangulation victims demonstrated additional findings of internal injuries compared to the standard clinical forensic examination. However, existing studies on the use of MRI for this purpose mostly focused on the first 48 h after the incident. The aims of this study were (a) to evaluate the longitudinal visibility of MRI findings after violence against the neck by performing two MRI examinations within 12 days and a minimum of four days between both MRI scans and (b) to assess which MRI sequences were most helpful for the detection of injuries. Twenty strangulation victims participated in this study and underwent one (n = 8) or two (n = 12) MRI scans. The first MRI examination was conducted during the first five days, the second five to 12 days after the incident. Two blinded radiologists assessed the MRI data and looked for lesions in the structures of the neck. In total, 140 findings were reported in the 32 MRI examinations. Most of the findings were detected in the thyroid and the muscles of the neck. T2-weighted SPACE with fat suppression, T1-weighted TSE and T1-weighted MPRAGE were rated as the most helpful MRI sequences. Subjects who showed findings in the initial scan also demonstrated comparable results in the second scan, which was performed on average 8.4 days after the incident. Our results show that even up to 12 days after the incident, the criminal proceeding of strangulation cases may greatly profit from the information provided by an MRI examination of the neck in addition to the standard clinical forensic examination.

Compromised dynamic cerebral autoregulation is a hemodynamic marker for predicting poor prognosis even with good recanalization after endovascular thrombectomy.

PURPOSE: In patients undergoing endovascular thrombectomy (EVT) with acute ischemic stroke (AIS), dynamic cerebral autoregulation (dCA) may minimize neurological injury from blood pressure fluctuations. This study set out to investigate the function of dCA in predicting clinical outcomes following EVT. METHODS: 43 AIS of the middle cerebral or internal carotid artery patients underwent with EVT, and 43 healthy individuals (controls) were enrolled in this case control research. The dCA was evaluated using transcranial Doppler 12 h and five days after EVT. The transfer function analysis was used to derive the dCA parameters, such as phase, gain, and coherence. The modified Rankin scale (mRS) at 3 months after EVT was used to assess the clinical outcomes. Thefavorable outcome group was defined with mRS ≤2 and the unfavorable outcome group was defined with mRS score of 3-6. Logistic regression analysis was performed to determine the risk factors of clinical outcomes. RESULTS: A significant impairment in dCA was observed on the ipsilateral side after EVT, particularly in patients with unfavorable outcomes. After 5 days, the ipsilateral phase was associated with poor functional outcomes (adjusted odds ratio [OR] = 0.911, 95% confidence interval [CI]: 0.854-0.972; P = 0.005) and the area under the curve (AUC) (AUC, 0.878, [95% CI: 0.756-1.000] P < 0.001) (optimal cutoff, 35.0°). Phase change was an independent predictor of clinical outcomes from 12 h to 5 days after EVT (adjusted OR = 1.061, 95% CI: 1.016-1.109, P = 0.008). CONCLUSIONS: dCA is impaired in patients with AIS after EVT. Change in dCA could be an independent factor related to the clinical outcomes.

Dual-Energy CT Iodine Uptake of Head and Neck: Definition of Reference Values in a Big Data Cohort.

BACKGROUND: Despite a considerable amount of literature on dual-energy CT (DECT) iodine uptake of the head and neck, the physiologic iodine uptake of this region has not been defined yet. This study aims to establish reference values for the iodine uptake of healthy organs to facilitate clinical application. METHODS: Consecutive venous DECT scans of the head and neck were reviewed, and unremarkable exams were included (n = 617). A total of 35 region of interest measurements were performed in 16 anatomical regions. Iodine uptake was compared among different organs/tissues and subgroup analysis was performed (male (n = 403) vs. female (n = 214); young (n = 207) vs. middle-aged (n = 206) vs. old (n = 204); and normal weight (n = 314) vs. overweight (n = 196) vs. obese (n = 107)). RESULTS: Overall mean iodine uptake values ranged between 0.5 and 9.4 mg/mL. Women showed higher iodine concentrations in the cervical vessels and higher uptake for the parotid gland, masseter muscle, submandibular glands, sublingual glands, palatine tonsils, tongue body, thyroid gland, and the sternocleidomastoid muscle than men (p ≤ 0.04). With increasing age, intravascular iodine concentrations increased as well as iodine uptake for cerebellum and thyroid gland, while values for the tongue and palatine tonsils were lower compared to younger subjects (p ≤ 0.03). Iodine concentrations for parotid glands and sternocleidomastoid muscles decreased with a higher BMI (p ≤ 0.004), while normal-weighted patients showed higher iodine values inside the jugular veins, other cervical glands, and tonsils versus patients with a higher BMI (p ≤ 0.04). CONCLUSION: physiologic iodine uptake values of cervical organs and tissues show gender-, age-, and BMI-related differences, which should be considered in the clinical routine of head and neck DECT.

Neuroimaging manifestations of paediatric histiocytoses.

Histiocytoses are rare multi-system disorders marked by abnormal histiocyte cell proliferation, affecting children with diverse clinical presentations. Classified into five groups in 2016, including Langerhans-related (L), cutaneous (C), malignant (M), Rosai-Dorfman disease (R) and haemophagocytic lymphohistiocytosis (H), newer entities such as ALK-positive histiocytosis have also emerged, heralding the era of molecular (sub)classification. Common entities include Langerhans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD) and haemophagocytic lymphohistiocytosis (HLH). This pictorial essay aids radiologists in recognising and differentiating paediatric histiocytoses based on unique neuroimaging features.

Malignant proliferative ependymoma of the neck with lymph node metastasis: A case report.

BACKGROUND: Malignant proliferating trichilemmal tumor (MPTT) is an infrequent malignant neoplasm originating from cutaneous appendages, with only a handful of documented cases. This report delineates a unique instance of MPTT situated in the neck, accompanied by lymph node metastasis. A comprehensive exposition of its clinical trajectory and imaging manifestation is presented, aiming to enhance comprehension and management of this atypical ailment. CASE SUMMARY: Patient concerns: A 79-year-old male presented with a longstanding right neck mass persisting for over six decades, exhibiting recent enlargement over the past year. Diagnoses: Enhanced magnetic resonance imaging of the neck unveiled an elliptical mass on the right neck side, characterized by an ill-defined border and a heterogeneous signal pattern. The mass exhibited subdued signal intensity on T1-weighted imaging (T1WI) and a heterogeneous high signal on T2-weighted imaging (T2WI), interspersed with a lengthy T1 and T2 cystic signal motif. Close anatomical association with the submandibular gland joint was noted, and intravenous gadolinium diethylene triamine pentaacetic acid administration facilitated conspicuous enhancement. Substantial enhancement of the solid segment prompted an initial preoperative diagnosis of malignant nerve sheath tumor. However, post-surgery histopathological and immunohistochemical analysis conclusively confirmed the diagnosis as malignant hyperplastic external hair root sheath tumor. Intervention: Complete excision of the tumor was successfully executed. Outcomes: The patient experienced a favorable postoperative recovery. CONCLUSION: Malignant proliferative trichilemmal tumor external hair root sheath tumor is a cystic-solid lesion, appearing as low signal on T1WI images or high signal on T2WI with enhancement of the solid component. Suspicions of malignancy are heightened when the tumor border is indistinct, tissue planes are breached, or when linear or patchy high signals are observed in the subcutaneous tissue on T1 liver acquisition with volume acceleration enhanced images along with intermediate signal on T2WI and restricted diffusion on diffusion-weighted imaging images. Strong consideration for malignancy should arise if there are signs of compromised adjacent tissue relationships or direct invasion evident on imaging. We have incorporated the above-mentioned content into the entire manuscript.

Assessing the Use of Telepresence-Guided Video-Based Head and Neck Ultrasound Training: A Step towards Minimizing Dependence on Human Resources?

The acquisition of ultrasound skills is an essential part of any medical student's education. University access restrictions in the context of the COVID-19 pandemic have highlighted the need for digitization in teaching. However, teaching manual skills in online courses has proven to be challenging, not least in terms of human resources. Therefore, the aim of this study was to set up a hybrid head and neck ultrasound course consisting of a preface of video-based self-study followed by supportive instruction by a tutor in telepresence and to evaluate the quality, effectiveness, and feasibility of this teaching method. Thirty-five students were shown video tutorials on systematic ultrasound of the neck course. Learning outcomes were analyzed using self-assessment questionnaires and external assessment by an experienced ultrasonographer. All participants demonstrated statistically significant learning improvement (p < 0.001) when comparing self-assessment scores before and after training. The mean self-assessment scores increased from 13.8 to 26.6 for the telepresence-guided group, from 16.6 to 27.3 for the web-based group, and from 14.0 to 26.2 for the in-person group. The external observer assessment also showed improvement, with mean scores of 46.7, 48.1, and 46.5, respectively. Overall results did not significantly differ when comparing different instruction modalities. A telepresence-guided video-based ultrasound course is well suited to teaching ultrasound skills similar to in-person courses and allows a more resource-efficient targeting of student needs.

Neuroradiology Applications of Dual and Multi-energy Computed Tomography.

Computed tomography (CT) imaging has become an essential diagnostic tool for most emergent clinical conditions, owing to its speed, accuracy, cost, and few contraindications, compared with MR imaging cross-sectional imaging. Spectral CT, which includes dual, multienergy, and photon-counting CT, is superior to conventional single-energy CT (SECT) in many respects. Spectral information enables differentiation between materials with similar Hounsfield Unit attenuations on SECT; examples include but are not limited to "virtual noncontrast," "virtual noncalcium," and most notably for neuro applications, "hemorrhage versus iodine." This article expands on the many possible benefits of spectral CT in neuroimaging.

Imaging Findings of Adenocarcinoma Arising from Lingual Foregut Duplication Cyst.

Lingual foregut duplication cysts are rare developmental anomalies with varied symptoms, and adenocarcinomas may develop from them. Radiological evaluations, including computed tomography and magnetic resonance imaging, can help diagnose these lesions and determine their extent. Abnormal enhancement should raise the suspicion of malignancy of a lingual foregut duplication cyst. Early detection and complete surgical resection of lingual foregut duplication cysts are necessary to prevent malignant transformations. Complete tumor resection with adjuvant radiotherapy or radiochemotherapy is recommended. The teaching point is that mucinous adenocarcinoma can develop from a lingual foregut duplication cyst, and radiological studies may aid in the diagnosis. Teaching Point: Adenocarcinomas can develop from lingual foregut duplication cysts, which are rare developmental anomalies, and radiologic studies may aid in the diagnosis.

Radiologically-guided balloon sialoplasty for benign salivary duct obstruction: a 7-year UK service evaluation.

Obstructive sialadenitis is the most common cause of non-malignant salivary gland disorders, with salivary gland strictures being responsible for approximately 23% of all benign obstructive disease. Significant advances in minimally invasive techniques, including radiologically-guided balloon sialoplasty, offer the potential for successful treatment with reduced complications. At present there is a paucity of follow-up data regarding patient outcomes and repeat interventions in those undergoing the procedure. Patients with parotid or submandibular gland sialadenitis secondary to gland stricture were identified and underwent radiologically-guided balloon sialoplasty at Queen Alexandra Hospital, Portsmouth, UK between 2015 and 2022. Patient outcomes, complications and reintervention rates were recorded prospectively over the seven-year period and analysed retrospectively. A total of 44 patients underwent radiologically-guided balloon sialoplasty. Forty (89%) underwent sialoplasty for parotid gland disease, with a minority (n = 5) receiving an intervention for submandibular gland strictures. A total of 37 (84%) had their obstruction successfully treated (82% of parotid gland obstructions and 100% of submandibular gland obstructions). Five patients (11%) required a repeat intervention. Seventeen successfully treated patients (85%) who attended follow-up clinic appointments described complete resolution of their symptoms, with the remaining three (15%) describing a partial response. Radiologically-guided balloon sialoplasty for the treatment of benign obstructive sialadenitis secondary to a gland stricture is a safe and effective method of eliminating the obstruction and relieving patients' symptoms. Most patients were symptom free at short-term follow up, with a minority requiring a second sialoplastic intervention.

Effects of scan parameters on the accuracies of iodine quantification and hounsfield unit values in dual layer dual-energy head and neck computed tomography: A phantom study conducted in a hospital in Japan.

INTRODUCTION: No study has investigated scan parameters in head and neck dual layer dual-energy computed tomography (DL-DECT). This study aimed to select the appropriate scan parameters in head and neck imaging by evaluating the scan parameter effects on the accuracies of CT numbers and conduct iodine quantification in DL-DECT. METHODS: A multi-energy phantom was scanned using a dual layer CT (DLCT) scanner. Reference materials of iodine, blood, calcium, and adipose were used. A helical scan was performed by using reference and several protocols. Iodine density and virtual monochromatic images (VMIs) at the energy of 50, 70, and 100 keV were reconstructed. The iodine concentrations and CT numbers in each protocol were measured. Moreover, the absolute percentage errors (APEs) of iodine quantifications and CT numbers (reference vs. each protocol) were compared. Equivalence was observed when APEs between reference and each protocol was within 5%. Statistical analysis was performed using appropriate software. RESULTS: The APEs between the high-tube-voltage and reference protocol were 23.7, 14.0, 8.8, and 8.1% for iodine reference materials with concentrations equal to 2, 5, 10, and 15 mg/ml, respectively. At 50 keV, APEs between the high-tube-voltage and reference protocols were greater than 5% except for calcium and adipose. At 100 keV, APEs between the high-tube-voltage and reference protocols were greater than 5% except for blood and calcium. CONCLUSIONS: The high-tube-voltage protocol improved the accuracies of the measurement for iodine quantification and CT numbers. Additionally, the scanning parameters except for tube voltage had no effect on accuracies of iodine quantitation and CT numbers in the DLCT scanner. IMPLICATIONS FOR PRACTICE: The use of the high-tube-voltage protocol will be recommended for more accurate material decomposition in head and neck DL-DECT.

The early effect of COVID-19 on dental infections by neuroimaging in the emergency department setting.

OBJECTIVES: In early 2020, at COVID-19's onset in the United States, the American Dental Association recommended postponing elective dental procedures to minimize viral spread. Subsequently, concerns arose that this could result in increased dental infections and resultant emergency department visits. This study quantifies the number and severity of dental infections at the onset of the early COVID-19 outbreak in early 2020 in the Northeast United States resulting in emergency room visits and radiographic imaging compared to 2017-2019 with an analysis of geographic population characteristics. METHODS: Cross-sectional head and neck imaging performed at an East Coast hospital system was retrospectively reviewed for dental infections from March 2020 through December 2020, and compared to prior years 2017-2019. Inclusion criteria included radiology reporting of a dental infection, ranging in severity. Electronic medical records (EMR) and imaging reports were queried for patient characteristics and dental findings. RESULTS: There were 735 confirmed imaging reports of odontogenic infections. There was a significant increase in imaging reporting of odontogenic infections in the post-shutdown period. These were more frequently early-type infections, involved a higher proportion of male and non-white patients, and the patients were more often from disadvantaged zip codes when compared with prior years. CONCLUSIONS: These findings highlight the varying impact of outpatient dental office closures on different socioeconomic groups in the setting of a pandemic. Potential implications include increased morbidity and mortality for patients, as well as increased cost and resource allocations for the healthcare system.

The Great Contrast Shortage of 2022-Lessons learnt in Australia.

INTRODUCTION: Computed tomography (CT) imaging is one of the most commonly used diagnostic tools. Iodine-based contrast media (IBCM) are frequently administered intravenously to improve soft tissue contrast in a wide range of CT scans. Supply chain disruptions triggered by the SARS-CoV-19 pandemic led to a global shortage of IBCM in mid-2022. The purpose of this study was to explore the impact of this shortage on the delivery of healthcare in Western Australia. METHODS: We performed a single-centre retrospective analysis of the provision of CT studies, comparing historical patterns to the shortage period. We focussed our attention on the total number of CT scans (noncontrast CT [NCCT] and contrast-enhanced CT [CECT]) and also specifically CT pulmonary angiogram (CTPA) and CT neck angiogram with or without inclusion of circle of Willis (CTNA) examinations. We also examined whether a decrease was compensated by increasing frequency of alternate examinations such as ventilation/perfusion (V/Q) scans, carotid Doppler ultrasound studies and Magnetic Resonance Angiograms (MRAs). RESULTS: Since 2012, there has been an approximate linear increase in the frequency of CT examinations. During the period of contrast shortage, there was an abrupt drop-off by approximately 50% in the CECT, CTPA and CTNA groups compared with the preceding 6 weeks (49%, 55% and 44%, respectively, with P < 0.001 in all cases). During the contrast shortage, the frequency of V/Q scans increased fivefold (from 13 to 65; P < 0.001). However, the provision of carotid Doppler ultrasound studies and MRAs remained approximately stable in frequency across recent time intervals. CONCLUSION: Our findings demonstrate that the IBCM shortage crisis had a very significant impact on the delivery of healthcare. While V/Q scans could (partially) substitute for CTPA studies in suspected pulmonary emboli, there appeared to be no valid alternative for CTNA studies in stroke calls. The unexpected and critical shortage of IBCM forced healthcare professionals to conserve resources, prioritise indications, triage patients based on risk, explore alternate imaging strategies and prepare for similar events recurring in the future.

Magnetic resonance diagnosis of laryngeal chondritis after transoral laser microsurgery for laryngeal cancer.

Objective: Laryngeal chondritis (LC) is a rare complication of carbon dioxide transoral laser microsurgery (CO2 TOLMS) for laryngeal tumours and can pose a diagnostic challenge. Its magnetic resonance (MR) features have not been previously described. This study aims to characterise a cohort of patients who developed LC after CO2 TOLMS and describe its clinical and MR findings. Methods: Clinical records and MR images of all patients presenting with LC after CO2 TOLMS between 2008 and 2022 were reviewed. Results: Seven patients were analysed. Timing of LC diagnosis ranged from 1 to 8 months after CO2 TOLMS. Four patients were symptomatic. Abnormal endoscopic findings included suspected tumour recurrence in 4 patients. MR documented focal or extensive signal changes involving the thyroid lamina and para-laryngeal space with T2 hyperintensity, T1 hypointensity and intense contrast enhancement (n = 7), and minimally reduced mean apparent diffusion coefficient (ADC) values (1.0-1.5 x 10-3 mm2/s) (n = 6). A favourable clinical outcome was achieved in all patients. Conclusions: LC after CO2 TOLMS has a distinctive MR pattern. When tumour recurrence cannot be confidently excluded based on imaging, antibiotic therapy, close clinical and radiological follow-up and/or biopsy are recommended.

Cervical Necrotizing Fasciitis, Diagnosis and Treatment of a Rare Life-Threatening Infection.

IMPORTANCE: Necrotizing fasciitis is a relatively uncommon and potentially life-threatening soft tissue infection, with morbidity and mortality approaching 25% to 35%, even with optimal treatment. The challenge of diagnosis for necrotizing soft tissue infections (NSTIs) is their rarity, with the incidence of approximately 1000 cases annually in the United States. Given the rapid progression of disease and its similar presentation to more benign processes, early and definitive diagnosis is imperative. FINDINGS: Signs and symptoms of NSTIs in the early stages are virtually indistinguishable from those seen with abscesses and cellulitis, making definitive diagnosis difficult. The clinical presentation will depend on the pathogen and its virulence factors which ultimately determine the area and depth of invasion into tissue. There are multiple laboratory value scoring systems that have been developed to support the diagnosis of an NSTI. The scoring system with the highest positive (92%) and negative (96%) predictive value is the laboratory risk indicator for necrotizing fasciitis (LRINEC). The score is determined by 6 serologic markers: C-reactive protein (CRP), total white blood cell (WBC) count, hemoglobin, sodium, creatinine, and glucose. A score ≥ 6 is a relatively specific indicator of necrotizing fasciitis (specificity 83.8%), but a score <6 is not sensitive (59.2%) enough to rule out necrotizing fasciitis. In terms of imaging, computed tomography (CT) imaging, while more sensitive (80%) than plain radiography in detecting abnormalities, is just as nonspecific. Computed tomography imaging of NSTIs demonstrates fascial thickening (with potential fat stranding), edema, subcutaneous gas, and abscess formation. Magnetic resonance imaging (MRI) has demonstrated sensitivity of 100% and specificity of 86%, though MRI may not show early cases of fascial involvement of necrotizing fasciitis. CONCLUSIONS AND RELEVANCE: Necrotizing soft tissue infections are rapidly progressive and potentially fatal infections that require a high index of clinical suspicion to promptly diagnose and aggressive surgical debridement of affected tissue in order to ensure optimal outcomes.Prompt surgical and infectious disease consultation is necessary for the treatment and management of these patients. While imaging is useful for further characterization, it should not delay surgical consultation. Necrotizing soft tissue infection remains a clinical diagnosis, although plain radiography, CT imaging, and ultrasound can provide useful clues. In general, the management of these patients should include rapid diagnosis, using a combination of clinical suspicion, laboratory data (LRINEC score), and imaging (MRI being the recommended imaging modality), prompt infectious disease and surgical consultation, surgical debridement, and delayed reconstruction. Laboratory findings that can more strongly suggest a diagnosis of NSTI include elevated CRP, elevated WBC, low hemoglobin, decreased sodium, and increased creatinine. Imaging findings include fascial thickening (with potential fat stranding), edema, subcutaneous gas, and abscess formation. Broad-spectrum antibiotics should be started in all cases of suspected NSTI. Surgical debridement, however, remains the lynchpin for treatment of cervical necrotizing fasciitis.

Development, Application, and Performance of Artificial Intelligence in Cephalometric Landmark Identification and Diagnosis: A Systematic Review.

This study aimed to analyze the existing literature on how artificial intelligence is being used to support the identification of cephalometric landmarks. The systematic analysis of literature was carried out by performing an extensive search in PubMed/MEDLINE, Google Scholar, Cochrane, Scopus, and Science Direct databases. Articles published in the last ten years were selected after applying the inclusion and exclusion criteria. A total of 17 full-text articles were systematically appraised. The Cochrane Handbook for Systematic Reviews of Interventions (CHSRI) and Newcastle-Ottawa quality assessment scale (NOS) were adopted for quality analysis of the included studies. The artificial intelligence systems were mainly based on deep learning-based convolutional neural networks (CNNs) in the included studies. The majority of the studies proposed that AI-based automatic cephalometric analyses provide clinically acceptable diagnostic performance. They have worked remarkably well, with accuracy and precision similar to the trained orthodontist. Moreover, they can simplify cephalometric analysis and provide a quick outcome in practice. Therefore, they are of great benefit to orthodontists, as with these systems they can perform tasks more efficiently.

Lessons learnt from the global iodinated contrast media shortage in head and neck imaging.

A recent shortage in the global supply of iodinated contrast media (ICM) has required health service providers to review their contrast administration policies and implement strategies to conserve inventory. This article will review the current best practices in head and neck imaging for a variety of common presentations and provide examples where alternative imaging can be considered due to the recent ICM shortage. Ultrasound and MRI techniques can feature heavily in many diagnostic processes in head and neck pathology, and a variety of common presentations can be appropriately investigated through clinical evaluation or naso-endoscopy. In many instances, for the routine assessment of non-acute adult and paediatric head and neck presentations, the use of contrast-enhanced CT can be safely minimised to conserve ICM if required.

Nearly Missed Pharyngeal Foreign Body: A Three-Year-Old van Gogh.

Foreign body injuries in the head and neck region can be life-threatening. Managing pediatric patients in this context may be increasingly challenging due to several medical and legal reasons. In order to optimize the management of foreign body injuries and to guide treatment procedures, various imaging techniques, with specific assets and liabilities, must be employed. Nevertheless, the "As Low As Reasonably Achievable'' principle must be kept in mind when managing pediatric patients since children are more radiosensitive than adults. Guidelines for imaging pediatric head traumas are provided by the American College of Radiology (ACR), relying on the Pediatric Emergency Care Applied Research Network (PECARN) severity classification. We report the case of a three-year-old child in whom a considerable delay occurred in diagnosing a foreign body impaction, due to an occult clinical presentation. In this case study, we focus on outlining the importance of considering advanced imaging investigations for children in the wake of traumatic events.

"AHead Start or a Pain in theNeck?"-Establishment and Evaluation of a Video-Based "Hands-On" Head and Neck Ultrasound Course.

The COVID-19 pandemic has strongly highlighted the need for more digitalization in healthcare. Teaching ultrasound skills in online courses is a key challenge in this context. The aim of this study was to establish an online video-based head and neck ultrasound course with an evaluation of the quality, effectiveness, and feasibility of this teaching method compared to in-person teaching. Twenty-two medical students were taught head and neck ultrasound in two groups: one group in an in-person course and the other one in a video-based course. Learning success was analyzed using self-evaluation forms and external assessment by an experienced ultrasonographer. Comparing pre- and post-training self-evaluation, all participants showed statistically significant learning progress. In the external assessment, the overall scores in both groups did not differ significantly. The courses themselves were positively evaluated by all participants. Herein, we present the first feasibility study of a web-based head and neck-ultrasound course for medical students. The methodology provides the potential for future changes in telemedical education and sustainable improvements in telemedical teaching and global intra-clinical and interdisciplinary patient care.

Image quality comparison of single-energy and dual-energy computed tomography for head and neck patients: a prospective randomized study.

OBJECTIVES: The aim of this study was to compare the quality of images obtained using single-energy computed tomography (SECT) performed with automated tube voltage adaptation (TVA) with dual-energy CT (DECT) weighted average images. METHODS: Eighty patients were prospectively randomized to undergo either SECT with TVA (n = 40, ref. mAs 200) or radiation dose-matched DECT (n = 40, 80/Sn150 kV, ref. mAs tube A 91/tube B 61) on a dual-source CT scanner. Objective image quality was evaluated as dose-normalized contrast-to-noise ratio (CNRD) for the jugular veins relative to fatty tissue and muscle tissue and for muscle tissue relative to fatty issue. For subjective image quality, reproduction of anatomical structures, image artifacts, image noise, spatial resolution, and overall diagnostic acceptability were evaluated at sixteen anatomical substructures using Likert-type scales. RESULTS: Effective radiation dose (ED) was comparable between SECT and DECT study groups (2.9 ± 0.6 mSv/3.1 ± 0.7 mSv, p = 0.5). All examinations were rated as excellent or good for clinical diagnosis. Compared to the CNRD in the SECT group, the CNRD in the DECT group was significantly higher for the jugular veins relative to fatty tissue (7.51/6.08, p < 0.001) and for muscle tissue relative to fatty tissue (4.18/2.90, p < 0.001). The CNRD for the jugular veins relative to muscle tissue (3.33/3.18, p = 0.51) was comparable between groups. Image artifacts were less pronounced and overall diagnostic acceptability was higher in the DECT group (all p = 0.01). CONCLUSIONS: DECT weighted average images deliver higher objective and subjective image quality than SECT performed with TVA in head and neck imaging. KEY POINTS: • Weighted average images derived from dual-energy CT deliver higher objective and subjective image quality than single-energy CT using automated tube voltage adaptation in head and neck imaging. • If available, dual-energy CT acquisition may be preferred over automated low tube voltage adopted single-energy CT for both malignant and non-malignant conditions.

Neumatización detenida del seno esfenoidal: una condición benigna que simula lesiones patológicas / Arrested pneumatization of the sphenoid sinus: a benign condition that simulates pathological lesions

Resumen La neumatización detenida de los senos paranasales es una condición benigna poco conocida, que consiste en una variación de la neumatización normal, permaneciendo médula ósea grasa dentro de la cavidad, siendo más frecuente en el seno esfenoidal. Es generalmente asintomática y su diagnóstico suele ser incidental en el contexto de la realización de imágenes por otras causas, existiendo criterios imagenológicos definidos para esta condición. Su manejo es expectante y es esencial su distinción de otros diagnósticos diferenciales, con objeto de evitar procedimientos y tratamientos invasivos que solo aporten morbilidad. Presentamos dos casos de pacientes, de 15 y 16 años que, en estudio imagenológico por otra causa, se observan lesiones esfenoidales heterogéneas con focos de baja señal sugerentes de calcificaciones, con características compatibles con neumatización detenida del seno esfenoidal.

Abstract Arrested pneumatization of the paranasal sinuses is an under-recognized benign condition, which consists of a variation of the normal pneumatization, with fatty bone marrow remaining within the cavity, more frequent in the sphenoid sinus. It is generally asymptomatic, and its diagnosis is usually incidental in the context of imaging for other causes, with defined imaging criteria for this condition. Its management is expectant and its distinction from other differential diagnoses is essential, in order to avoid invasive procedures and treatments that only contribute morbidity. We present two cases of 15- and 16-year-old patients who, on imaging for another reason, show heterogeneous sphenoid lesions with low-signal foci suggestive of calcifications, with characteristics compatible with arrested pneumatization of the sphenoid sinus.