Protocol optimization for abdominal imaging using photon-counting CT: a consensus of two academic institutions

PURPOSE

Photon-counting detector CT (PCD CT) is a promising technology for abdominal imaging due to its ability to provide high spatial and contrast resolution images with reduced patient radiation exposure. However, there is currently no consensus regarding the optimal imaging protocols for PCD CT. This article aims to present the PCD CT abdominal imaging protocols used by two tertiary care academic centers in the United States.

METHODS

A review of PCD CT abdominal imaging protocols was conducted by two abdominal radiologists at different academic institutions. Protocols were compared in terms of acquisition parameters and reconstruction settings. Both imaging centers independently selected similar protocols for PCD CT abdominal imaging, using QuantumPlus mode.

RESULTS

There were some differences in the use of reconstruction kernels and iterative reconstruction levels, however the individual combination at each site resulted in similar image impressions. Overall, the imaging protocols used by both centers provide high-quality images with low radiation exposure.

CONCLUSION

These findings provide valuable insights into the development of standardized protocols for PCD CT abdominal imaging, which can help to ensure consistent as well as high-quality imaging across different institutions and allow for future multicenter research collaborations.

Photon Counting Computed Tomography-Applications

Photon-counting detector CT (PCCT) is a new technology that has recently emerged as a powerful tool for a more precise, patient-centered imaging. Ever since the FDA approved the first Photon-counting system on September 30, 2021, this new technology raised much interest all over the scientific community and numerous studies have been published in a short period of time. By the end of 2022, the first results of phantom and in-vivo studies started showing the great potential of this new imaging modality, with benefits that range from neuroradiology to abdominal imaging and the promise to push previous limits of both patient size and age as well as image resolution. In this article, we will provide a brief explanation of how commercially available photon-counting detector CTs work and how they differ from energy-integrating detector CT systems. Then we will focus on the different clinical applications of this new technology with an in-depth systematic approach based on the most recent evidence. Because nearly every subspecialty of radiology has had impressive results, we will delve into each of these subspecialties and explain how every single domain can undergo significant transformation. This includes a wide range of possibilities, from the opportunistic screening of many different pathologies to the ability of seeing small structures with unprecedented precision, as well as a new kind of multi-energy imaging that can provide much more information on tissue characteristics, all while maintaining a lighter workflow and post-processing burden compared to what has been observed in the past.

Radiomics-based machine learning for the diagnosis of lymph node metastases in patients with head and neck cancer: Systematic review

Machine learning (ML) is increasingly used to detect lymph node (LN) metastases in head and neck (H&N) carcinoma. We systematically reviewed the literature on radiomic-based ML for the detection of pathological LNs in H&N cancer. A systematic review was conducted in PubMed, EMBASE, and the Cochrane Library. Baseline study characteristics and methodological quality items (modeling, performance evaluation, clinical utility, and transparency items) were extracted and evaluated. The qualitative synthesis is presented using descriptive statistics. Seven studies were included in this study. Overall, the methodological quality items were generally favorable for modeling (57% of studies). The studies were mostly unsuccessful in terms of transparency (85.7%), evaluation of clinical utility (71.3%), and assessment of generalizability employing independent or external validation (72.5%). ML may be able to predict LN metastases in H&N cancer. Further studies are warranted to improve the generalizability assessment, clinical utility evaluation, and transparency items.

Artificial Intelligence Applied to Pancreatic Imaging: A Narrative Review

The diagnosis, evaluation, and treatment planning of pancreatic pathologies usually require the combined use of different imaging modalities, mainly, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). Artificial intelligence (AI) has the potential to transform the clinical practice of medical imaging and has been applied to various radiological techniques for different purposes, such as segmentation, lesion detection, characterization, risk stratification, or prediction of response to treatments. The aim of the present narrative review is to assess the available literature on the role of AI applied to pancreatic imaging. Up to now, the use of computer-aided diagnosis (CAD) and radiomics in pancreatic imaging has proven to be useful for both non-oncological and oncological purposes and represents a promising tool for personalized approaches to patients. Although great developments have occurred in recent years, it is important to address the obstacles that still need to be overcome before these technologies can be implemented into our clinical routine, mainly considering the heterogeneity among studies.

Prognostic findings for ICU admission in patients with COVID-19 pneumonia: baseline and follow-up chest CT and the added value of artificial intelligence

Infection with SARS-CoV-2 has dominated discussion and caused global healthcare and economic crisis over the past 18 months. Coronavirus disease 19 (COVID-19) causes mild-to-moderate symptoms in most individuals. However, rapid deterioration to severe disease with or without acute respiratory distress syndrome (ARDS) can occur within 1-2 weeks from the onset of symptoms in a proportion of patients. Early identification by risk stratifying such patients who are at risk of severe complications of COVID-19 is of great clinical importance. Computed tomography (CT) is widely available and offers the potential for fast triage, robust, rapid, and minimally invasive diagnosis: Ground glass opacities (GGO), crazy-paving pattern (GGO with superimposed septal thickening), and consolidation are the most common chest CT findings in COVID pneumonia. There is growing interest in the prognostic value of baseline chest CT since an early risk stratification of patients with COVID-19 would allow for better resource allocation and could help improve outcomes. Recent studies have demonstrated the utility of baseline chest CT to predict intensive care unit (ICU) admission in patients with COVID-19. Furthermore, developments and progress integrating artificial intelligence (AI) with computer-aided design (CAD) software for diagnostic imaging allow for objective, unbiased, and rapid assessment of CT images.

An approach to evaluate the quality of radiological reports in Head and Neck cancer loco-regional staging: experience of two Academic Hospitals

OBJECTIVES

To evaluate the quality of the reports of loco-regional staging computed tomography (CT) or magnetic resonance imaging (MRI) in head and neck (H&N) cancer.

METHODS

Consecutive reports of staging CT and MRI of all H&N cancer cases from 2018 to 2020 were collected. We created lists of quality indicators for tumor (T) for each district and for node (N). We marked these as 0 or 1 in the report calculating a report score (RS) and a maximum sum (MS) of each list. Two radiologists and two otolaryngologists in consensus classified reports as low quality (LQ) if the RS fell in the percentage range 0-59% of MS and as high quality (HQ) if it fell in the range 60-100%, annotating technique and district. We evaluated the distribution of reports in these categories.

RESULTS

Two hundred thirty-seven reports (97 CT and 140 MRI) of 95 oral cavity, 52 laryngeal, 47 oropharyngeal, 19 hypo-pharyngeal, 14 parotid, and 10 nasopharyngeal cancers were included. Sixty-six percent of all the reports were LQ for T, 66% out of all the MRI reports, and 65% out of all CT reports were LQ. Eight-five percent of reports were HQ for N, 85% out of all the MRI reports, and 82% out of all CT reports were HQ. Reports of oral cavity, oro-nasopharynx, and parotid were LQ, respectively, in 76%, 73%, 100% and 92 out of cases.

CONCLUSION

Reports of staging CT/MRI in H&N cancer were LQ for T description and HQ for N description.

750 Mitral annulus disjunction in consecutive patients undergoing cardiovascular magnetic resonance: arrhythmogenic substrate or anatomical variant?

Aims

Mitral annulus disjunction (MAD) has been associated with sudden cardiac death in selected patients with arrhythmic presentation, while its clinical significance in unselected cohorts remains unknown. Our purpose was to assess the prevalence and clinical significance of MAD in consecutive patients referred to cardiovascular-magnetic-resonance (CMR).

Methods and results

Our population included 103 consecutive patients undergoing CMR at our Institution, between August and September 2021. MAD was defined as a  ≥ 1 mm atrial displacement of the mitral leaflet hinge point in standard long-axis cine images during end-systole. MAD analysis was performed in 97 patients (feasibility = 94%) and resulted positive in 49 (51%). MAD—patients were more often males (75% vs. 57%; P = 0.045) and affected by ischaemic (35% vs. 12%, P = 0.01) and non-ischaemic cardiomyopathy (38% vs. 16%, P = 0.026) compared to MAD+ patients. No significant differences were found in terms of age, history of ventricular arrhythmias, bi-ventricular and bi-atrial volumes, bi-ventricular ejection fraction, native T1 and T2 mapping values, extracellular volume, and prevalence of late gadolinium enhancement (P > 0.05 for all) between MAD + vs. MAD—patients. MAD extent was higher in patients with mitral valve prolapse (MVP; n = 7), (3.5 ± 1.5 mm in MVP+ vs. 2.0 ± 1.0 mm in MVP– patients; P = 0.004). No significant differences were conversely found in MAD extent between patients with and without ventricular arrhythmias (2.5 ± 1.1 mm vs. 2.3 ± 1.1 mm; P = 0.815).

Conclusions

Our findings suggest a high prevalence of MAD in unselected cohorts of patients, with no clinical significance. Prospective studies are needed to further elucidate the interplay between MAD and malignant ventricular arrhythmias in unselected cohorts of patients.

Volume-of-Interest Aware Deep Neural Networks for Rapid Chest CT-Based COVID-19 Patient Risk Assessment

Since December 2019, the world has been devastated by the Coronavirus Disease 2019 (COVID-19) pandemic. Emergency Departments have been experiencing situations of urgency where clinical experts, without long experience and mature means in the fight against COVID-19, have to rapidly decide the most proper patient treatment. In this context, we introduce an artificially intelligent tool for effective and efficient Computed Tomography (CT)-based risk assessment to improve treatment and patient care. In this paper, we introduce a data-driven approach built on top of volume-of-interest aware deep neural networks for automatic COVID-19 patient risk assessment (discharged, hospitalized, intensive care unit) based on lung infection quantization through segmentation and, subsequently, CT classification. We tackle the high and varying dimensionality of the CT input by detecting and analyzing only a sub-volume of the CT, the Volume-of-Interest (VoI). Differently from recent strategies that consider infected CT slices without requiring any spatial coherency between them, or use the whole lung volume by applying abrupt and lossy volume down-sampling, we assess only the "most infected volume" composed of slices at its original spatial resolution. To achieve the above, we create, present and publish a new labeled and annotated CT dataset with 626 CT samples from COVID-19 patients. The comparison against such strategies proves the effectiveness of our VoI-based approach. We achieve remarkable performance on patient risk assessment evaluated on balanced data by reaching 88.88%, 89.77%, 94.73% and 88.88% accuracy, sensitivity, specificity and F1-score, respectively.

Sudden neck swelling with rash as late manifestation of COVID-19: a case report

BACKGROUND

Although there are reports of otolaryngological symptoms and manifestations of CoronaVirus Disease 19 (COVID-19), there have been no documented cases of sudden neck swelling with rash in patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection described in literature.

CASE PRESENTATION

We report a case of a sudden neck swelling and rash likely due to late SARS-CoV-2 in a 64-year-old woman. The patient reported COVID-19 symptoms over the previous three weeks. Computed Tomography (CT) revealed a diffuse soft-tissue swelling and edema of subcutaneous tissue, hypodermis, and muscular and deep fascial planes. All the differential diagnoses were ruled out. Both the anamnestic history of the patient's husband who had died of COVID-19 with and the collateral findings of pneumonia and esophageal wall edema suggested the association with COVID-19. This was confirmed by nasopharyngeal swab polymerase chain reaction. The patient was treated with lopinavir/ritonavir, hydroxychloroquine and piperacillin/tazobactam for 7 days. The neck swelling resolved in less than 24 h, while the erythema was still present up to two days later. The patient was discharged after seven days in good clinical condition and with a negative swab.

CONCLUSION

Sudden neck swelling with rash may be a coincidental presentation, but, in the pandemic context, it is most likely a direct or indirect complication of COVID-19.