Publications by authors named "Alex Nagelschneider"

Background: SynthesiZed Improved Resolution and Concurrent nOise reductioN (ZIRCON) is a multi-kernel synthesis method that creates a single series of thin-slice computed tomography (CT) images displaying low noise and high spatial resolution, increasing reader efficiency and minimizing partial volume averaging.

Purpose: To compare the diagnostic performance of a single set of ZIRCON images to two routine clinical image series using conventional CT head and bone reconstruction kernels for diagnosing intracranial findings and fractures in patients with trauma or suspected acute neurologic deficit.

Material And Methods: In total, 50 patients underwent clinically indicated head CT in the ER (15 normal, 35 abnormal cases).

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Several imaging modalities are utilized in the diagnosis, treatment, and surveillance of head and neck cancer. First-line imaging remains computed tomography (CT); however, MRI, PET with CT (PET/CT), and ultrasound are often used. In the last decade, several new imaging modalities have been developed that have the potential to improve early detection, modify treatment, decrease treatment morbidity, and augment surveillance.

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Background And Purpose: Photon-counting detector CT (PCD-CT) is now clinically available and offers ultra-high-resolution (UHR) imaging. Our purpose was to prospectively evaluate the relative image quality and impact on diagnostic confidence of head CTA images acquired by using a PCD-CT compared with an energy-integrating detector CT (EID-CT).

Materials And Methods: Adult patients undergoing head CTA on EID-CT also underwent a PCD-CT research examination.

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Extranodal extension of tumour on histopathology is known to be a negative prognostic factor in head and neck cancer. Compelling evidence suggests that extranodal extension detected on radiological imaging is also a negative prognostic factor. Furthermore, if imaging detected extranodal extension could be identified reliably before the start of treatment, it could be used to guide treatment selection, as patients might be better managed with non-surgical approaches to avoid the toxicity and cost of trimodality therapy (surgery, chemotherapy, and radiotherapy together).

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Photon-counting CT (PCCT) uses a novel X-ray detection mechanism that confers many advantages over that used in traditional energy integrating CT. As PCCT becomes more available, it is important to thoroughly understand its benefits and highest yield areas for improvements in diagnosis of various diseases. Based on our early experience, we have identified several areas of neurovascular imaging in which PCCT shows promise.

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Historically, MR imaging has been unable to detect a pituitary adenoma in up to one-half of patients with Cushing disease. This issue is problematic because the standard-of-care treatment is surgical resection, and its success is correlated with finding the tumor on imaging. Photon-counting detector CT is a recent advancement that has multiple benefits over conventional energy-integrating detector CT.

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Background: The Alberta Stroke Program Early CT Score ASPECTS) is used to quantify the extent of injury to the brain following acute ischemic stroke (AIS) and to inform treatment decisions. The e-ASPECTS software uses artificial intelligence methods to automatically process non-contrast CT (NCCT) brain scans from patients with AIS affecting the middle cerebral artery (MCA) territory and generate an ASPECTS. This study aimed to evaluate the impact of e-ASPECTS (Brainomix, Oxford, UK) on the performance of US physicians compared to a consensus ground truth.

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Background: Computed tomography (CT) angiography collateral score (CTA-CS) is an important clinical outcome predictor following mechanical thrombectomy for ischemic stroke with large vessel occlusion (LVO). The present multireader study aimed to evaluate the performance of e-CTA software for automated assistance in CTA-CS scoring.

Materials And Methods: Brain CTA images of 56 patients with anterior LVO were retrospectively processed.

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Article Synopsis
  • HPV-associated oropharyngeal squamous cell carcinoma (HPV[+]OPSCC) needs refined clinical staging to enhance treatment decisions, specifically by analyzing the number of radiographically positive lymph nodes in patients classified as clinical N1 (cN1).
  • A study involving 260 patients who underwent surgical treatment and various radiation therapies found that the count of positive lymph nodes significantly influenced progression-free survival (PFS), with higher counts correlating to worse outcomes.
  • The findings suggest using the number of positive lymph nodes as a meaningful categorization tool for cN1 patients with HPV(+)OPSCC, warranting further research to validate these results.
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Background And Purpose: Radiation therapy is an important component of treatment in patients with malignancies of the head, neck, and spine. However, radiation to these regions has well-known potential side effects, many of which can be encountered on imaging. In this manuscript, we review selected radiographic manifestations of therapeutic radiation to the head, neck, and spine that may be encountered in the practice of radiology.

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Article Synopsis
  • The study investigates the effectiveness of CT and PET/CT scans in detecting involvement of more than 4 lymph nodes (rN2) and extranodal extension (rENE) in patients with HPV-positive oropharyngeal cancer.
  • Results showed CT had a sensitivity of 59% and specificity of 92% for detecting more than 4 lymph nodes, while both imaging techniques performed similarly overall.
  • Patients with fewer than 4 involved lymph nodes (rN0-1) had a high likelihood of being classified as pN0-1, indicating that rN0-1 status can help guide treatment decisions and clinical trial participation.
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Introduction: There is increased interest in the use of artificial intelligence-based (AI) software packages in the evaluation of neuroimaging studies for acute ischemic stroke. We studied whether, compared to standard image interpretation without AI, Brainomix e-ASPECTS software improved interobserver agreement and accuracy in detecting ASPECTS regions affected in anterior circulation LVO.

Methods: We included 60 consecutive patients with anterior circulation LVO who had TICI 3 revascularization within 60 minutes of their baseline CT.

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Background And Purpose: Radiation therapy is commonly utilized in the majority of solid cancers and many hematologic malignancies and other disorders. While it has an undeniably major role in improving cancer survival, radiation therapy has long been recognized to have various negative effects, ranging from mild to severe. In this manuscript, we review several intracranial manifestations of therapeutic radiation, with particular attention to those that may be encountered by radiologists.

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Background: Recurrent pleomorphic adenoma (PA) can be a lifelong disease, and rates of subsequent recurrence are high.

Methods: Patients between 2000 and 2015 were identified. Primary outcome was subsequent recurrence after surgical salvage.

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Article Synopsis
  • * A database of 741 MRI exams from 729 unique patients was compiled, where 641 exams were used for training the DL system, and 100 were set aside for testing through a blinded assessment platform.
  • * Neuroradiologists rated the mean scores of DL segmentations higher than those from technicians (7.31 vs 6.97), and the DL method demonstrated a strong overlap in segmentations with a Dice coefficient of 0.87, indicating its potential to outperform human segmentations.
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Background: In patients presenting with recurrent pleomorphic adenoma (rPA), clinical evaluation can fail to recognize carcinoma ex PA (cxPA). We aim to identify the risk factors for cxPA.

Methods: This is a single institution retrospective case-control study from 2000 to 2015.

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Purpose: To compare recurrent pleomorphic adenoma tumor burden as detected on magnetic resonance and computerized tomography imaging with postoperative histopathology.

Materials And Methods: 44 patients were identified at a tertiary medical center between 2000 and 2015. Patients were included if they had viewable preoperative imaging and a postoperative diagnosis of recurrent pleomorphic adenoma.

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Objective: The purpose of this study was to evaluate the performance of three metal artifact reduction methods in dual-energy CT (DECT) examinations of instrumented spines.

Materials And Methods: Twenty patients with instrumented spines who underwent spine DECT were retrospectively identified. All scans were obtained on a dual-source 128-MDCT scanner.

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Purpose: This resident-driven quality improvement project was undertaken to assess the effectiveness of structured reporting to reduce revision rates for afterhours reports dictated by residents.

Methods: The first part of the study assessed baseline revision rates for head and neck CT angiography (CTA) examinations dictated by residents during afterhours call. A structured report was subsequently created based on templates on the RSNA informatics reporting website and critical findings that should be assessed for on all CTA examinations.

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Benign granulomatous processes such as fungal infection may mimic metastatic lung cancer on FDG PET/CT. We found that these processes often have draining lymph node(s) with equal or greater FDG activity than associated lung nodule(s), a "flip-flop" of what is commonly seen in lung cancer. The aim of this study was to examine the utility of this "flip-flop fungus" (FFF) sign for diagnosing benign pulmonary disease.

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