Individual Imaging Modalities Research Articles

Exploiting the Photo-Physical Properties of Metal Halide Perovskite Nanocrystals for Bioimaging.

Perovskite nanomaterials have recently been exploited for bioimaging applications due to their unique photo-physical properties, including high absorbance, good photostability, narrow emissions, and nonlinear optical properties. These attributes outperform conventional fluorescent materials such as organic dyes and metal chalcogenide quantum dots and endow them with the potential to reshape a wide array of bioimaging modalities. Yet, their full potential necessitates a deep grasp of their structure-attribute relationship and strategies for enhancing water stability through surface engineering for meeting the stringent and unique requirements of each individual imaging modality. This review delves into this evolving frontier, highlighting how their distinctive photo-physical properties can be leveraged and optimized for various bioimaging modalities, including visible light imaging, near-infrared imaging, and super-resolution imaging.

Diagnostic Yield and Utility of Radiographic Imaging in the Evaluation of Pulsatile Tinnitus: A Systematic Review.

The objective of this study is to assess diagnostic yield of imaging modalities used to evaluate patients presenting with pulsatile tinnitus (PT). PubMed, Embase, and Scopus were queried using the search terms "pulsatile tinnitus," "pulse-synchronous tinnitus," and "pulse synchronous tinnitus" with no date limitations. Studies that reported diagnostic imaging for patients presenting with PT were included. Data were reviewed for sample size, gender, age, imaging study, indications, and diagnoses. The primary outcome measure from aggregated data was the yield of positive diagnoses made with each imaging modality. The quality of evidence was assessed for risk of bias. From an initial search of 1145 articles, 17 manuscripts met inclusion criteria, of which 12 studies evaluated individual imaging modalities. The number of unique patients included was 1232. The diagnostic yield varied between modalities: carotid ultrasound (21%, 95% confidence interval [CI]: 12%-35%), CT temporal bone (65%, CI: 20%-93%), computed tomographic angiography (86%, CI: 80%-90%), and MRI/magnetic resonance angiography (58%, CI: 43%-72%). Studies on the diagnostic approach to PT are limited by heterogeneity in both inclusion criteria and reporting standards. A wide range of imaging modalities are used in practice during the initial evaluation of PT, and the diagnostic yield for imaging can be improved by utilizing more specific clinical indications.

Comparison of the different imaging modalities used to image pediatric oncology patients: A COG diagnostic imaging committee/SPR oncology committee white paper.

Diagnostic imaging is essential in the diagnosis and management, including surveillance, of known or suspected cancer in children. The independent and combined roles of the various modalities, consisting of radiography, fluoroscopy, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine (NM), are both prescribed through protocols but also function in caring for complications that may occur during or subsequent to treatment such as infection, bleeding, or organ compromise. Use of a specific imaging modality may be based on situational circumstances such as a brain CT or MR for a new onset seizure, chest CT for respiratory signs or symptoms, or US for gross hematuria. However, in many situations, there are competing choices that do not easily lend themselves to a formulaic approach as options; these situations depend on the contributions of a variety of factors based on a combination of the clinical scenario and the strengths and limitations of the imaging modalities. Therefore, an improved understanding of the potential influence of the imaging decision pathways in pediatric cancer care can come from comparison among the individual diagnostic imaging modalities. The purpose of the following material to is to provide such a comparison. To do this, pediatric imaging content experts for the individual modalities of radiography and fluoroscopy, US, CT, MRI, and NM will discuss the individual modality strengths and limitations.

Diagnostic Imaging in the Evaluation of Asymptomatic Microhematuria: Systematic Review and Meta-analysis.

Microhematuria is a highly prevalent condition with a low associated risk of urothelial and upper tract malignancy. The AUA Guidelines recently changed recommendations for imaging favoring renal ultrasound for low and intermediate risk patients with microhematuria. We summarize the diagnostic test characteristics of computed tomography urography, renal ultrasound, and magnetic resonance urography in comparison with surgical pathology for the diagnosis of upper urinary tract cancer in microhematuria and gross hematuria patients. This study is a systematic review and meta-analysis using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines from evidence collected for the 2020 AUA Microhematuria Guidelines report, including studies assessing imaging following diagnosis of hematuria published from January 2010 through December 2019. The search identified 20 studies which reported the prevalence of malignant and benign diagnoses in relation to imaging modality, of which 6 were included in the quantitative analysis. For the detection of renal cell carcinoma and upper urinary tract carcinoma in patients with microhematuria and gross hematuria, computed tomography urography had a sensitivity of 94% (95% CI, 84%-98%) and a specificity of 99% (95%CI, 97%-100%) with a certainty of evidence rating of very low and low, respectively when 4 studies were pooled. In comparison, ultrasound demonstrated a sensitivity ranging from 14%-96% (low certainty of evidence) and a specificity of 99%-100% in 2 studies (moderate certainty of evidence), while magnetic resonance urography demonstrated a sensitivity of 83% and specificity of 86% in 1 study with a low certainty of evidence. In a limited data set for each individual imaging modality, computed tomography urography appears the most sensitive imaging modality for the diagnostic evaluation of microhematuria. Future studies will be needed to evaluate the clinical and health system financial impacts of the change in guideline recommendations from computed tomography urography to renal ultrasound in evaluating low and intermediate risk patients with microhematuria.

Abstract P3-04-04: Correlation of Mammographic Microcalcifications with Final Surgical Pathology after Neoadjuvant Chemotherapy for Breast Cancer

Abstract Introduction: Benefits of neoadjuvant chemotherapy (NAC) in breast cancer include de-escalating surgical management, treating occult systemic metastases and the assessment of in-vivo tumor response. Guidelines for post-NAC imaging to assess response lack specificity on appropriateness and utility of individual imaging modalities for surgical planning. Mammographic microcalcifications are a confounder that are not well studied. We examined the correlation between the mammographic extent of microcalcifications present post-NAC, corresponding MRI lesions, and definitive surgical pathology. Methods: In this retrospective cohort study, patients with calcifications on pre-NAC mammograms were collected from a database of consecutive breast cancer patients receiving NAC at an academic center between January 1st 2014 – December 31st 2019. The primary objective was to determine how the maximum diameter of post-NAC calcifications correlates with final surgical pathology, stratified by tumor receptor subtype. The secondary objectives were to assess correlation of the maximum diameter on final pathology with the maximum diameter of (1) post-NAC mammographic mass (if present) and (2) post-NAC MRI, mass (ME) and non-mass enhancement (NME). Parameters on final surgical pathology included the diameters of invasive disease, ductal carcinoma in-situ (DCIS) and the tumor bed (TB). Pearson’s correlation coefficient was used to evaluate statistical significance and considered strong if R2 ≥70%, moderate if R2 = 25-70% and weak if R2 ≤25%. Results: 343 patients received NAC, of which 157 were excluded for lack of calcifications (n=147), lack of imaging reports (n=8) or inflammatory breast cancer (n=2). 186 patients met the inclusion criteria with a mean age of 49.9 years. 34 (18.3%) patients had triple negative breast cancers (TNBCs). Mammographic calcifications correlated poorly with residual invasive disease (R2= 10.8%), overestimating by 57%. TNBCs demonstrated the strongest correlation between microcalcifications and invasive disease (R2=83%), but calcifications overestimated pathology by 41%. Mammographic calcifications correlated moderately with the TB (R2= 50.3%) and poorly with DCIS (R2 = 3.4%). By subtype, both correlations were strong in TNBCs (R2 = 76.3% and 77.9% respectively). Similarly, focal mass on mammography correlated poorly with pathology except in TNBCs, which correlated moderately with all three pathology parameters (Table 1). In patients with calcifications on mammography, MRI ME and NME correlated weakly with invasive disease, except in TNBCs, where correlation was moderate in ME (R2 = 37.7%) and NME (R2 = 28.4%). Conclusion: In breast cancer patients with microcalcifications, current post-NAC imaging modalities appear to overestimate the extent of residual disease. Surgical excision of all residual microcalcifications may maximize oncologic safety but may also represent over-treatment. Ongoing feasibility trials on surgical omission rely on post-NAC imaging to determine trial candidacy. Our data suggests that potentially eligible patients are excluded on the basis of post-NAC imaging overestimating the extent of residual disease. Further studies are needed to determine the most accurate imaging correlate of residual disease after NAC to plan better surgeries, identify candidates for surgical omission and establish optimal post-NAC imaging guidelines. Current imaging modalities appear most accurate for TNBCs and may be more reliable at identifying exceptional responders for surgical omission in this subtype. Table 1. Summary of Correlation Analyses in Overall and Triple Negative Breast Cancer (TNBC) cohorts. * Average % difference in maximal diameter calculated as (pathology – radiology)/radiology Citation Format: Riordan M. Azam, Nicole Look Hong, David Lim. Correlation of Mammographic Microcalcifications with Final Surgical Pathology after Neoadjuvant Chemotherapy for Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-04-04.

“Circumnavigation”: A Worthy Descriptor to Depict Torrential Mitral Regurgitation and a Reverence to Ferdinand Magellan

"Circumnavigation" is never used as a verb in cardiology. Hypertrophic obstructive cardiomyopathy is a complex entity that often involves the mitral valve leading to eccentric mitral regurgitation. Utilizing multimodality imaging, assessing the severity of mitral regurgitation, and phenotyping the type of myocardial hypertrophy are achievable with certainty. We describe a case of a 42-year-old male who presented with palpitations and was ultimately diagnosed with hypertrophic obstructive cardiomyopathy with a mitral regurgitation. The torrential mitral regurgitation jet was so severe that it was "circumnavigating" the left atrium. In addition, we also draw historical parallelism with Magellan's heroic "circumnavigation" of the globe as we celebrate 500 years of his journey. Furthermore, we also describe the multimodality assessment of hypertrophic obstructive cardiomyopathy utilizing transthoracic echocardiography and cardiac magnetic resonance imaging. We discuss the challenges in quantifying such severe mitral regurgitation with any individual imaging modality.

Individual vs. combined imaging modalities for diagnosing neovascular central serous chorioretinopathy.

To assess the diagnostic accuracy of individual and combined imaging modalities compared with multimodal imaging for the detection of choroidal neovascularization (CNV) in central serous chorioretinopathy (CSC). We analyzed patients with CSC with and without CNV who had indocyanine green angiography (ICGA), structural optical coherence tomography (OCT), and OCT angiography (OCTA) obtained on the same day. The presence of CNV was determined using multimodal imaging by a senior retina specialist (i.e., diagnostic reference). Individual and combined (i.e., ICGA + structural OCT) imaging modalities were then graded by two expert readers for the presence of CNV. Sensitivity, specificity, positive (PPV), and negative (NPV) predictive values were computed for individual and combined imaging modalities relative to the diagnostic reference. CNV was detected in 17 eyes in 17 out of 33 CSC patients according to the reference standard. Using ICGA, the identification of CNV had a sensitivity of 66.7%, specificity of 66.7%, PPV of 70.6%, and NPV of 62.5%. Structural OCT had the following diagnostic accuracy values: 83.3% of sensitivity, 53.3% of specificity, 68.1% of PPV, and 72.7% of NPV. Using OCTA, CNV was graded to be present with a sensitivity of 77.8%, specificity of 86.7%, PPV of 87.5%, and NPV of 76.5%. The combination of ICGA and structural OCT granted the identification of CNV with a sensitivity of 83.3%, specificity of 86.7%, PPV of 88.2%, and NPV of 81.3%. OCTA has an elevated diagnostic accuracy in identifying CSC-associated CNV, though a combination of ICGA and structural OCT has a comparable diagnostic efficiency.

Omniparticle Contrast Agent for Multimodal Imaging: Synthesis and Characterization in an Animal Model.

Individual imaging modalities have certain advantages, but each suffers from drawbacks that other modalities may overcome. The goal of this study was to create a novel contrast agent suitable for various imaging modalities that after a single administration can bridge and strengthen the collaboration between the research fields as well as enrich the information obtained from any one modality. The contrast agent platform is based on dextran-coated iron oxide nanoparticles (for MRI and MPI) and synthesized using a modified co-precipitation method, followed by a series of conjugation steps with a fluorophore (for fluorescence and photoacoustic imaging), thyroxine (for CT imaging), and chelators for radioisotope labeling (for PET imaging). The fully conjugated agent was then tested in vitro in cell uptake, viability, and phantom studies and in vivo in a model of intraductal injection and in a tumor model. The agent was synthesized, characterized, and tested in vitro where it showed the ability to produce a signal on MRI/MPI/FL/PA/CT and PET images. Studies in cells showed the expected concentration-dependent uptake of the agent without noticeable toxicity. In vivo studies demonstrated localization of the agent to the ductal tree in mice after intraductal injection with different degrees of resolution, with CT being the best for this particular application. In a model of injected labeled tumor cells, the agent produced a signal with all modalities and showed persistence in tumor cells confirmed by histology. A fully functional omniparticle contrast agent was synthesized and tested in vitro and in vivo in two animal models. Results shown here point to the generation of a potent signal in all modalities tested without detrimental toxicity. Future use of this agent includes its exploration in various models of human disease including image-guided diagnostic and therapeutic applications.

Influence of Prior Imaging Information on Diagnostic Accuracy for Focal Skeletal Processes-A Retrospective Analysis of the Consistency between Biopsy-Verified Imaging Diagnoses.

Introduction: Comparing imaging examinations with those previously obtained is considered mandatory in imaging guidelines. To our knowledge, no studies are available on neither the influence, nor the sequence, of prior imaging and reports on diagnostic accuracy using biopsy as the reference standard. Such data are important to minimize diagnostic errors and to improve the preparation of diagnostic imaging guidelines. The aim of our study was to provide such data. Materials and methods: A retrospective cohort of 216 consecutive skeletal biopsies from patients with at least 2 different imaging modalities (X-ray, CT and MRI) performed within 6 months of biopsy was identified. The diagnostic accuracy of the individual imaging modality was assessed. Finally, the possible influence of the sequence of imaging modalities was investigated. Results: No significant difference in the accuracy of the imaging modalities was shown, being preceded by another imaging modality or not. However, the sequence analyses indicate sequential biases, particularly if MRI was the first imaging modality. Conclusion: The sequence of the imaging modalities seems to influence the diagnostic accuracy against a pathology reference standard. Further studies are needed to establish evidence-based guidelines for the strategy of using previous imaging and reports to improve diagnostic accuracy.

Post-mortem perinatal imaging: what is the evidence?

Post-mortem imaging for the investigation of perinatal deaths is an acceptable tool amongst parents and religious groups, enabling a less invasive autopsy examination. Nevertheless, availability is scarce nationwide, and there is some debate amongst radiologists regarding the best practice and optimal protocols for performing such studies. Much of the published literature to date focusses on single centre experiences or interesting case reports. Diagnostic accuracy studies are available for a variety of individual imaging modalities (e.g. post-mortem CT, MRI, ultrasound and micro-CT), however, assimilating this information is important when attempting to start a local service.In this article, we present a comprehensive review summarising the latest research, recently published international guidelines, and describe which imaging modalities are best suited for specific indications. When the antenatal clinical findings are not supported by the post-mortem imaging, we also suggest how and when an invasive autopsy may be considered. In general, a collaborative working relationship within a multidisciplinary team (consisting of radiologists, radiographers, the local pathology department, mortuary staff, foetal medicine specialists, obstetricians and bereavement midwives) is vital for a successful service.

RADIOGRAPHIC OSTEOARTHRITIS PROGRESSION PREDICTION VIA MULTI-MODAL IMAGING DATA AND DEEP LEARNING

Purpose: Prediction of radiographic osteoarthritis progression over short- and mid-terms may deepen understanding of the disease etiology and support the related clinical research. Prior imaging-oriented studies have focused mainly on individual imaging modalities. In particular, end-to-end deep learning methods have become increasingly common for knee X-rays. On the other hand, MR image analysis has been largely limited to manually designed imaging biomarkers. Such biomarkers are typically derived from rather small sample sizes and concern only the primarily affected tissues.

Imaging of Neuroendocrine Neoplasms: Monitoring Treatment Response-AJR Expert Panel Narrative Review.

Neuroendocrine neoplasms (NENs) encompass a broad spectrum of tumors throughout the body and range in biologic behavior from indolent to aggressive. Consequently, a wide spectrum of treatment options are available for NENs, including observation, somatostatin analogues, targeted therapy, chemotherapy, surgical resection, liver-directed therapy (embolization and ablation), and peptide receptor radionuclide therapy. Given the wide variety of tumor behaviors and treatments, precise criteria for treatment response in NENs are lacking. Though conventional anatomic imaging with CT and MRI remains important for NEN response assessment, the use of somatostatin receptor (SSR) PET is increasing and often provides synergistic and complementary information. Additionally, in certain clinical scenarios, a particular imaging strategy may prove superior or inferior to others for the detection of metastatic disease and evaluation of therapy response. A strong need exists to further define appropriate and standardized assessment criteria for tumor response and progression in NEN. This article presents the strengths and weaknesses of individual imaging modalities for evaluating NEN therapy response, including conventional anatomic imaging, SSR PET, FDG PET, dual-tracer PET, and PET/MRI. Ongoing challenges and unmet needs in the use of imaging for NEN response evaluation are explored.

NIR-I Dye-Based Probe: A New Window for Bimodal Tumor Theranostics.

Near-infrared (NIR, 650–1700 nm) bioimaging has emerged as a powerful strategy in tumor diagnosis. In particular, NIR-I fluorescence imaging (650–950 nm) has drawn more attention, benefiting from the high quantum yield and good biocompatibility. Since their biomedical applications are slightly limited by their relatively low penetration depth, NIR-I fluorescence imaging probes have been under extensive development in recent years. This review summarizes the particular application of the NIR-I fluorescent dye-contained bimodal probes, with emphasis on related nanoprobes. These probes have enabled us to overcome the drawbacks of individual imaging modalities as well as achieve synergistic imaging. Meanwhile, the application of these NIR-I fluorescence-based bimodal probes for cancer theranostics is highlighted.

Reticular Pseudodrusen on the Risk of Progression in Intermediate Age-Related Macular Degeneration

To examine the association between reticular pseudodrusen (RPD) and progression to late age-related macular degeneration (AMD) in individuals with intermediate AMD. Prospective cohort study. Two hundred eighty eyes from 140 participants with bilateral large drusen underwent multimodal imaging (MMI), including optical coherence tomography (OCT), near-infrared reflectance (NIR), fundus autofluorescence, and color fundus photography (CFP), at 6-monthly intervals up over a 36-month follow-up period. The presence of RPD per eye was determined based on either a combined MMI criterion, or each individual imaging modality, and their extent measured on combined OCT and NIR imaging. The association between the presence of RPD on different imaging modalities, and their extent, with the development of late AMD (including OCT-defined atrophy) was evaluated. The presence of RPD on MMI, or any of its individual modalities, at baseline was not significantly associated with an increased rate of developing late AMD, with or without adjusting for risk factors for AMD progression (age, drusen volume on OCT, and pigmentary abnormalities on CFP; all P ≥ 0.205). The extent of RPD present was also not significantly associated with an increased rate of developing late AMD, with or without adjustment for risk factors for AMD progression (both P ≥ 0.522). In this cohort with bilateral large drusen, the presence of RPD was not significantly associated with an increased risk of developing late AMD. Additional longitudinal studies in all stages of AMD are needed to understand the implications of RPD on vision loss in this condition.

Development and validation of a novel model incorporating MRI-based radiomics signature with clinical biomarkers for distinguishing pancreatic carcinoma from mass-forming chronic pancreatitis

PurposeIt is difficult to make a clear differential diagnosis of pancreatic carcinoma (PC) and mass-forming chronic pancreatitis (MFCP) via conventional examinations. We aimed to develop a novel model incorporating an MRI-based radiomics signature with clinical biomarkers for distinguishing the two lesions. MethodsA total of 102 patients were retrospectively enrolled and randomly divided into the training and validation cohorts. Radiomics features were extracted from four different sequences. Individual imaging modality radiomics signature, multiparametric MRI (mp-MRI) radiomics signature, and a final mixed model based on mp-MRI and clinically independent risk factors were established to discriminate between PC and MFCP. The diagnostic performance of each model and model discrimination were assessed in both the training and validation cohorts. ResultsADC had the best predictive performance among the four individual radiomics models, but there were no significant differences between the pairs of models (all p > 0.05). Six potential radiomics features were finally selected from the 960 texture features to formulate the radiomics score (rad-score) of the mp-MRI model. In addition, the boxplot results of the distributions of rad-scores identified the rad-score as an independent predictive factor for the differentiation of PC and MFCP (p< 0.001). Notably, the nomogram integrating rad-score and clinically independent risk factors had a better diagnostic performance than the mp-MRI and clinical models. These results were further confirmed by the validation group. ConclusionThe mixed model was developed and preliminarily validated to distinguish PC from MFCP, which may benefit the formulation of treatment strategies and nonsurgical procedures.

Inflammatory changes of the hip joint

Die Osteoarthrose ist die häufigste Ursache für den Hüftschmerz des Erwachsenen. Daher wird anderen Ursachen wie z. B. Entzündungen weniger Beachtung für den Gelenkschmerz in der Erstdiagnose geschenkt. Dieser Artikel gibt eine Übersicht von unterschiedlichen rheumatologischen Erkrankungen der Hüfte und deren Interpretation in der Bildgebung. Die Vor- und Nachteile der einzelnen bildgebenden Verfahren werden anhand der pathologischen Befunde für die rheumatologischen Erkrankungen erläutert.

Current landscape and future perspectives in preclinical MR and PET imaging of brain metastasis.

Brain metastasis (BM) is a major cause of cancer patient morbidity. Clinical magnetic resonance imaging (MRI) and positron emission tomography (PET) represent important resources to assess tumor progression and treatment responses. In preclinical research, anatomical MRI and to some extent functional MRI have frequently been used to assess tumor progression. In contrast, PET has only to a limited extent been used in animal BM research. A considerable culprit is that results from most preclinical studies have shown little impact on the implementation of new treatment strategies in the clinic. This emphasizes the need for the development of robust, high-quality preclinical imaging strategies with potential for clinical translation. This review focuses on advanced preclinical MRI and PET imaging methods for BM, describing their applications in the context of what has been done in the clinic. The strengths and shortcomings of each technology are presented, and recommendations for future directions in the development of the individual imaging modalities are suggested. Finally, we highlight recent developments in quantitative MRI and PET, the use of radiomics and multimodal imaging, and the need for a standardization of imaging technologies and protocols between preclinical centers.

Advanced zoomed diffusion-weighted imaging vs. full-field-of-view diffusion-weighted imaging in prostate cancer detection: a radiomic features study.

We aimed to compare the efficiency of prostate cancer (PCa) detection using a radiomics signature based on advanced zoomed diffusion-weighted imaging and conventional full-field-of-view DWI. A total of 136 patients, including 73 patients with PCa and 63 without PCa, underwent multi-parametric magnetic resonance imaging (mp-MRI). Radiomic features were extracted from prostate lesion areas segmented on full-field-of-view DWI with b-value = 1500s/mm2 (f-DWIb1500), advanced zoomed DWI images with b-value = 1500s/mm2 (z-DWIb1500), calculated zoomed DWI with b-value = 2000s/mm2 (z-calDWIb2000), and apparent diffusion coefficient (ADC) maps derived from both sequences (f-ADC and z-ADC). Single-imaging modality radiomics signature, mp-MRI radiomics signature, and a mixed model based on mp-MRI and clinically independent risk factors were built to predict PCa probability. The diagnostic efficacy and the potential net benefits of each model were evaluated. Both z-DWIb1500 and z-calDWIb2000 had significantly better predictive performance than f-DWIb1500 (z-DWIb1500 vs. f-DWIb1500: p = 0.048; z-calDWIb2000 vs. f-DWIb1500: p = 0.014). z-ADC had a slightly higher area under the curve (AUC) value compared with f-ADC value but was not significantly different (p = 0.127). For predicting the presence of PCa, the AUCs of clinical independent risk factors model, mp-MRI model, and mixed model were 0.81, 0.93, and 0.94 in training sets, and 0.74, 0.92, and 0.93 in validation sets, respectively. Radiomics signatures based on the z-DWI technology had better diagnostic accuracy for PCa than that based on the f-DWI technology. The mixed model was better at diagnosing PCa and guiding clinical interventions for patients with suspected PCa compared with mp-MRI signatures and clinically independent risk factors. • Advanced zoomed DWI technology can improve the diagnostic accuracy of radiomics signatures for PCa. • Radiomics signatures based on z-calDWIb2000 have the best diagnostic performance among individual imaging modalities. • Compared with the independent clinical risk factors and the mp-MRI model, the mixed model has the best diagnostic efficiency.

956P Combined accuracy of computed tomography and magnetic resonance imaging in detecting level wise metastatic neck nodes and extracapsular spread

The presence of metastatic neck node and extracapsular spread(ECS) has a poorer survival impact on oral squamous cell carcinoma(OSCC) patients. The debate of addressing the neck in superficial tumors <3 mm is still ongoing. Moreover, ECS has been recently added in the new clinical staging system and imaging plays an important role for the same. There are several studies reporting accuracy of individual imaging modalities in detecting metastatic node. However, combined use of these imaging techniques may be supplementary, especially with equivocal finding.

Advanced Sandwich Composite Cores for Patient Support in Advanced Clinical Imaging and Oncology Treatment.

Ongoing advances in both imaging and treatment for oncology purposes have seen a significant rise in the use of not only the individual imaging modalities, but also their combination in single systems such as Positron Emission Tomography combined with Computed Tomography (PET–CT) and PET–MRI (Magnetic Resonance Imaging) when planning for advanced oncology treatment, the most demanding of which is proton therapy. This has identified issues in the availability of suitable materials upon which to support the patient undergoing imaging and treatment owing to the differing requirements for each of the techniques. Sandwich composites are often selected to solve this issue but there is little information regarding optimum materials for their cores. In this paper, we presented a range of materials which are suitable for such purposes and evaluated the performance for use in terms of PET signal attenuation, proton beam stopping, MRI signal shading and X-Ray CT visibility. We found that Extruded Polystyrene offers the best compromise for patient support and positioning structures across all modalities tested, allowing for significant savings in treatment planning time and delivering more efficient treatment with lower margins.