Purpose To determine whether cardiac MRI strain parameters independently predict PET/CT-defined myocardial inflammation in patients with cardiac sarcoidosis (CS). Materials and Methods This retrospective study included patients with definite or probable CS who underwent cardiac MRI and fluorine 18 fluorodeoxyglucose (FDG) PET/CT between January 2010 and October 2022 within 90 days per the Japanese Circulation Society criteria. Strain parameters, including the peak circumferential strain (PCS), peak longitudinal strain (PLS), and diastolic strain rates, were calculated using feature tracking on cine steady-state free precession images. Inflammation was defined by focal FDG uptake using the 17-segment American Heart Association model. T2-weighted and late gadolinium enhancement (LGE) images were qualitatively assessed. Segment-level comparisons were performed between inflamed and noninflamed segments. Multivariable logistic regression clustered at the patient level was adjusted for LGE, T2 signal abnormality, age, sex, and left ventricular end-diastolic volume index. Receiver operating characteristic (ROC) curve analysis was used to evaluate the added value of strain metrics over the left ventricular ejection fraction (LVEF) for inflammation. Results Among 125 included patients (mean age, 59.5 years ± 12.7 [SD]), 60% (n = 75) had at least one segment with inflammation on FDG PET/CT images. Of these 75 patients, 61% (n = 46) were male. Segment-level analysis revealed inflammation in 18.1% (385 of 2125) of the segments. The PCS and PLS were lower in inflamed segments than in noninflamed segments (-14.1% vs -18.4% and -10.3% vs -13.0%, respectively; P < .001 for both) and independently predicted inflammation in multivariable analysis (odds ratio, 1.79 and 1.62, respectively; P < .01 for both). Adding PCS to LVEF improved inflammation detection (area under the ROC curve, 0.72 vs 0.63; P = .04). Conclusion Circumferential and longitudinal strain from cardiac MRI independently predicted PET-defined myocardial inflammation. Keywords: MRI, PET/CT, Heart, Cardiomyopathy, Cardiac Strain, Cardiac Sarcoidosis, Myocardial Inflammation © RSNA, 2026.

Abstract Background Diagnostic radiology residents in low- and middle-income countries (LMICs) may have to provide significant contributions to the clinical workload before the completion of their residency training. Because of time constraints inherent to the delivery of acute care, some of the most clinically impactful diagnostic radiology errors arise from the use of Computed Tomography (CT) in the management of acutely ill patients. As a result, it is paramount to ensure that radiology trainees reach adequate skill levels prior to assuming independent on-call responsibilities. We partnered with the radiology residency program at the Aga Khan University Hospital in Nairobi (Kenya) to evaluate a novel cloud-based testing method that provides an authentic radiology viewing and interpretation environment. It is based on Lifetrack, a unique Google Chrome-based Picture Archiving and Communication System, that enables a complete viewing environment for any scan, and provides a novel report generation tool based on Active Templates which are a patented structured reporting method. We applied it to evaluate the skills of AKUHN trainees on entire CT scans representing the spectrum of acute non-trauma abdominal pathology encountered in a typical on-call setting. We aimed to demonstrate the feasibility of remotely testing the authentic practice of radiology and to show that important observations can be made from such a Lifetrack-based testing approach regarding the radiology skills of an individual practitioner or of a cohort of trainees. Methods A total of 13 anonymized trainees with experience from 12 months to over 4 years took part in the study. Individually accessing the Lifetrack tool they were tested on 37 abdominal CT scans (including one normal scan) over six 2-hour sessions on consecutive days. All cases carried the same clinical history of acute abdominal pain. During each session the trainees accessed the corresponding Lifetrack test set using clinical workstations, reviewed the CT scans, and formulated an opinion for the acute diagnosis, any secondary pathology, and incidental findings on the scan. Their scan interpretations were composed using the Lifetrack report generation system based on active templates in which segments of text can be selected to assemble a detailed report. All reports generated by the trainees were scored on four different interpretive components: (a) acute diagnosis, (b) unrelated secondary diagnosis, (c) number of missed incidental findings, and (d) number of overcalls. A 3-score aggregate was defined from the first three interpretive elements. A cumulative score modified the 3-score aggregate for the negative effect of interpretive overcalls. Results A total of 436 scan interpretations and scores were available from 13 trainees tested on 37 cases. The acute diagnosis score ranged from 0 to 1 with a mean of 0.68 ± 0.36 and median of 0.78 (IQR: 0.5-1), and there were 436 scores. An unrelated secondary diagnosis was present in 11 cases, resulting in 130 secondary diagnosis scores. The unrelated secondary diagnosis score ranged from 0 to 1, with mean score of 0.48 ± 0.46 and median of 0.5 (IQR: 0–1). There were 32 cases with incidental findings, yielding 390 scores for incidental findings. The number of missed incidental findings ranged from 0 to 5 with a median at 1 (IQR: 1–2). The incidental findings score ranged from 0 to 1 with a mean of 0.4 ± 0.38 and median of 0.33 (IQR: 0- 0.66). The number of overcalls ranged from 0 to 3 with a median at 0 (IQR: 0–1) and a mean of 0.36 ± 0.63. The 3-score aggregate ranged from 0 to 100 with a mean of 65.5 ± 32.5 and median of 77.3 (IQR: 45.0, 92.5). The cumulative score ranged from − 30 to 100 with a mean of 61.9 ± 35.5 and median of 71.4 (IQR: 37.4, 92.0). The mean acute diagnosis scores and SD by training period were 0.62 ± 0.03, 0.80 ± 0.05, 0.71 ± 0.05, 0.58 ± 0.07, and 0.66 ± 0.05 for trainees with ≤ 12 months, 12–24 months, 24–36 months, 36–48 months and > 48 months respectively. The mean acute diagnosis score of 12–24 months training was the only statistically significant greater score when compared to ≤ 12 months by the ANOVA with Tukey testing (p = 0.0002). We found a similar trend with distribution of 3-score aggregates and cumulative scores. There were no significant associations when the training period was categorized as less than and more than 2 years. We looked at the distribution of the 3-score aggregate versus the number of overcalls by trainee, and we found that the 3-score aggregate was inversely related to the number of overcalls. Heatmaps and raincloud plots provided an illustrative means to visualize the relative performance of trainees across cases. Conclusion We demonstrated the feasibility of remotely testing the authentic practice of radiology and showed that important observations can be made from our Lifetrack-based testing approach regarding radiology skills of an individual or a cohort. From observed weaknesses areas for targeted teaching can be implemented, and retesting could reveal their impact. This methodology can be customized to different LMIC environments and expanded to board certification examinations.

Background: In the context of a phase II trial of risk-adaptive chemoradiation, we evaluated whether tumor metabolic response could serve as a correlate of treatment sensitivity and toxicity. Methods: Forty-five patients with AJCCv7 stage IIB-IIIB NSCLC enrolled on the FLARE-RT phase II trial (NCT02773238). [18F]fluorodeoxyglucose (FDG) PET-CT images were acquired prior to treatment and after 24 Gy during week 3. Patients with unfavorable on-treatment tumor response received concomitant boosts to 74 Gy total over 30 fractions rather than standard 60 Gy. Metabolic tumor volume and mean standardized uptake value (SUVmean) were calculated semi-automatically. Risk factors of pulmonary toxicity included concurrent chemotherapy regimen, adjuvant anti-PDL1 immunotherapy, and lung dosimetry. Incidence of CTCAE v4 grade 2+ pneumonitis was analyzed using the Fine-Gray method with competing risks of metastasis or death. Peripheral germline DNA microarray sequencing measured pre-defined candidate genes from distinct pathways: 96 DNA repair, 53 immunology, 38 oncology, 27 lung biology.Results: Twenty-four patients received proton therapy, 23 received ICI, 26 received carboplatin-paclitaxel, and 17 pneumonitis events were observed. Pneumonitis risk was significantly higher for patients with COPD (HR 3.78 [1.48, 9.60], p = 0.005), those treated with immunotherapy (HR 2.82 [1.03, 7.71], p = 0.043) but not with carboplatin-paclitaxel (HR 1.98 [0.71, 5.54], p = 0.19). Pneumonitis rates were similar among selected patients receiving 74 Gy radiation vs 60 Gy (p = 0.33), proton therapy vs photon (p = 0.60), or with higher lung dosimetric V20 (p = 0.30). Patients in the upper quartile decrease in SUVmean (>39.7%) were at greater risk for pneumonitis (HR 4.00 [1.54, 10.44], p = 0.005) and remained significant in multivariable analysis (HR 3.34 [1.23, 9.10], p = 0.018). Germline DNA gene alterations in immunology pathways were most frequently associated with pneumonitis.Conclusion: Tumor metabolic response as measured by mean SUV is associated with increased pneu-monitis risk in a clinical trial cohort of NSCLC patients independent of treatment factors. This may be par-tially attributed to patient-specific differences in immunogenicity.& COPY; 2023 Elsevier B.V. All rights reserved. Radiotherapy and Oncology 185 (2023) 1-8

Introduction: Radiomics analysis provides quantitative pixel-signal-intensity information on cardiac magnetic resonance (CMR). Hypothesis: Can radiomics improve performance of CMR for detection of myocardial inflammation in cardiac sarcoidosis (CS)? We aim to assess the added value of CMR radiomics to standard CMR image analysis for the diagnosis of active CS. Methods: We retrospectively analyzed CS patients referred for both CMR and F18-FDG-PET/CT(PET) within 90 days of each other. Myocardium was segmented on a dedicated semi-automated workflow by MIM encore software and features extracted by pyradiomics. PET were reviewed for the presence of myocardial FDG uptake, defining segments with inflammation. CMR-segments were reviewed for the presence of late gadolinium enhancement(LGE) and increased T2 signal by 2 experienced radiologists. Analysis was performed to assess for differences in radiomics features in segments with/without inflammation. ROC analysis was conducted to define the added value of radiomics for diagnosis of myocardial inflammation. Results: In 80 patients with 1360 AHA-CMR segments (mean age 58 years, 62.5% male) with CS, 276(20.3%) segments had FDG uptake on PET/CT, 252(18.5%) segments showed LGE and 54(3.9%) segments had increased signal on T2W images. Significant quantitative differences for LGE-derived radiomics features were highest for Entropy and Gray Level Cooccurrence Matrix Autocorrelation between segments with and without inflammation on PET (Table1). The presence of LGE was the best independent predictor for inflammation on PET. T2W abnormality alone was not an independent predictor from the presence of LGE. Significant improvement was seen in area under the curve when radiomics features were combined with standard CMR predictors (LGE/T2W) vs standard CMR predictors alone. Conclusions: Quantitative radiomics features on LGE-CMR have the potential to improve the ability of CMR for assessment of inflammation in CS.

Background Lung volume reduction surgery (LVRS) and medical therapy are 2 available treatment options in dealing with severe emphysema, which is a chronic lung disease. However, or there are currently limited guidelines on the timing of LVRS for patients with different characteristics. Objective The objective of this study is to assess the timing of receiving LVRS in terms of patient outcomes, taking into consideration a patient’s characteristics. Methods A finite-horizon Markov decision process model for patients with severe emphysema was developed to determine the short-term (5 y) and long-term timing of emphysema treatment. Maximizing the expected life expectancy, expected quality-adjusted life-years, and total expected cost of each treatment option were applied as the objective functions of the model. To estimate parameters in the model, the data provided by the National Emphysema Treatment Trial were used. Results The results indicate that the treatment timing strategy for patients with upper-lobe predominant emphysema is to receive LVRS regardless of their specific characteristics. However, for patients with non–upper-lobe–predominant emphysema, the optimal strategy depends on the age, maximum workload level, and forced expiratory volume in 1 second level. Conclusion This study demonstrates the utilization of clinical trial data to gain insights into the timing of surgical treatment for patients with emphysema, considering patient age, observable health condition, and location of emphysema. Highlights Both short-term and long-term Markov decision process models were developed to assess the timing of receiving lung volume reduction surgery in patients with severe emphysema. How clinical trial data can be used to estimate the parameters and obtain short-term results from the Markov decision process model is demonstrated. The results provide insights into the timing of receiving lung volume reduction surgery as a function of a patient’s characteristics, including age, emphysema location, maximum workload, and forced expiratory volume in 1 second level.

Background Acute COVID‐19–related myocardial, pulmonary, and vascular pathology and how these relate to each other remain unclear. To our knowledge, no studies have used complementary imaging techniques, including molecular imaging, to elucidate this. We used multimodality imaging and biochemical sampling in vivo to identify the pathobiology of acute COVID‐19. Specifically, we investigated the presence of myocardial inflammation and its association with coronary artery disease, systemic vasculitis, and pneumonitis. Methods and Results Consecutive patients presenting with acute COVID‐19 were prospectively recruited during hospital admission in this cross‐sectional study. Imaging involved computed tomography coronary angiography (identified coronary disease), cardiac 2‐deoxy‐2‐[fluorine‐18]fluoro‐D‐glucose positron emission tomography/computed tomography (identified vascular, cardiac, and pulmonary inflammatory cell infiltration), and cardiac magnetic resonance (identified myocardial disease) alongside biomarker sampling. Of 33 patients (median age 51 years, 94% men), 24 (73%) had respiratory symptoms, with the remainder having nonspecific viral symptoms. A total of 9 patients (35%, n=9/25) had cardiac magnetic resonance–defined myocarditis. Of these patients, 53% (n=5/8) had myocardial inflammatory cell infiltration. A total of 2 patients (5%) had elevated troponin levels. Cardiac troponin concentrations were not significantly higher in patients with and without myocarditis (8.4 ng/L [interquartile range, IQR: 4.0–55.3] versus 3.5 ng/L [IQR: 2.5–5.5]; P=0.07) or myocardial cell infiltration (4.4 ng/L [IQR: 3.4–8.3] versus 3.5 ng/L [IQR: 2.8–7.2]; P=0.89). No patients had obstructive coronary artery disease or vasculitis. Pulmonary inflammation and consolidation (percentage of total lung volume) was 17% (IQR: 5%–31%) and 11% (IQR: 7%–18%), respectively. Neither were associated with the presence of myocarditis. Conclusions Myocarditis was present in a third patients with acute COVID‐19, and the majority had inflammatory cell infiltration. Pneumonitis was ubiquitous, but this inflammation was not associated with myocarditis. The mechanism of cardiac pathology is nonischemic and not attributable to a vasculitic process. Registration URL: https://www.isrctn.com; Unique identifier: ISRCTN12154994.

Purpose: We sought to examine the prognostic value of fluorodeoxyglucose-positron emission tomography (PET) imaging during chemoradiation for unresectable non-small cell lung cancer for survival and hypothesized that tumor PET response is correlated with peripheral T-cell function. Methods and Materials: Forty-five patients with American Joint Committee on Cancer version 7 stage IIB-IIIB non-small cell lung cancer enrolled in a phase II trial and received platinum-doublet chemotherapy concurrent with 6 weeks of radiation (NCT02773238). Fluorodeoxyglucose-PET was performed before treatment start and after 24 Gy of radiation (week 3). PET response status was prospectively defined by multifactorial radiologic interpretation. PET responders received 60 Gy in 30 fractions, while nonresponders received concomitant boosts to 74 Gy in 30 fractions. Peripheral blood was drawn synchronously with PET imaging, from which germline DNA sequencing, T-cell receptor sequencing, and plasma cytokine analysis were performed. Results: Median follow-up was 18.8 months, 1-year overall survival (OS) 82%, 1-year progression-free survival 53%, and 1-year locoregional control 88%. Higher midtreatment PET total lesion glycolysis was detrimental to OS (1 year 87% vs 63%, P <.001), progression-free survival (1 year 60% vs 26%, P =.044), and locoregional control (1 year 94% vs 65%, P =.012), even after adjustment for clinical/treatment factors. Twenty-nine of 45 patients (64%) were classified as PET responders based on a priori definition. Higher tumor programmed death-ligand 1 expression was correlated with response on PET (P =.017). Higher T-cell receptor richness and clone distribution slope were associated with improved OS (P =.018-0.035); clone distribution slope was correlated with PET response (P =.031). Conclusions: Midchemoradiation PET imaging is prognostic for survival; PET response may be linked to tumor and peripheral T-cell biomarkers.

Background Patients undergoing chemoradiation and immune checkpoint inhibitor (ICI) therapy for locally advanced non-small cell lung cancer (NSCLC) experience pulmonary toxicity at higher rates than historical reports. Identifying biomarkers beyond conventional clinical factors and radiation dosimetry is especially relevant in the modern cancer immunotherapy era. We investigated the role of novel functional lung radiomics, relative to functional lung dosimetry and clinical characteristics, for pneumonitis risk stratification in locally advanced NSCLC. Methods Patients with locally advanced NSCLC were prospectively enrolled on the FLARE-RT trial (NCT02773238). All received concurrent chemoradiation using functional lung avoidance planning, while approximately half received consolidation durvalumab ICI. Within tumour-subtracted lung regions, 110 radiomics features (size, shape, intensity, texture) were extracted on pre-treatment [ 99m Tc]MAA SPECT/CT perfusion images using fixed-bin-width discretization. The performance of functional lung radiomics for pneumonitis (CTCAE v4 grade 2 or higher) risk stratification was benchmarked against previously reported lung dosimetric parameters and clinical risk factors. Multivariate least absolute shrinkage and selection operator Cox models of time-varying pneumonitis risk were constructed, and prediction performance was evaluated using optimism-adjusted concordance index (c-index) with 95% confidence interval reporting throughout. Results Thirty-nine patients were included in the study and pneumonitis occurred in 16/39 (41%) patients. Among clinical characteristics and anatomic/functional lung dosimetry variables, only the presence of baseline chronic obstructive pulmonary disease (COPD) was significantly associated with the development of pneumonitis (HR 4.59 [1.69–12.49]) and served as the primary prediction benchmark model (c-index 0.69 [0.59–0.80]). Discrimination of time-varying pneumonitis risk was numerically higher when combining COPD with perfused lung radiomics size (c-index 0.77 [0.65–0.88]) or shape feature classes (c-index 0.79 [0.66–0.91]) but did not reach statistical significance compared to benchmark models (p > 0.26). COPD was associated with perfused lung radiomics size features, including patients with larger lung volumes (AUC 0.75 [0.59–0.91]). Perfused lung radiomic texture features were correlated with lung volume (adj R 2 = 0.84–1.00), representing surrogates rather than independent predictors of pneumonitis risk. Conclusions In patients undergoing chemoradiation with functional lung avoidance therapy and optional consolidative immune checkpoint inhibitor therapy for locally advanced NSCLC, the strongest predictor of pneumonitis was the presence of baseline chronic obstructive pulmonary disease. Results from this novel functional lung radiomics exploratory study can inform future validation studies to refine pneumonitis risk models following combinations of radiation and immunotherapy. Our results support functional lung radiomics as surrogates of COPD for non-invasive monitoring during and after treatment. Further study of clinical, dosimetric, and radiomic feature combinations for radiation and immune-mediated pneumonitis risk stratification in a larger patient population is warranted.

We present a case of indolent neurolymphomatosis in a 55-year-old male patient with worsening pain and weakness in his right leg over the past few months. The patient has a past medical history of type II diabetes mellitus, four-year history of worsening left foot drop, left lower limb pain and weakness attributed to diabetic amyotrophy, and back pain. The new right-sided symptoms prompted further imaging which revealed a left sciatic nerve mass which was biopsied. Initial biopsy results were inconclusive. 18F-FDG PET/CT revealed the full extent of this patient's disease and helped plan for a more representative biopsy site, which finally established a diagnosis of diffuse large B-cell lymphoma involving the lumbosacral nerve roots. The patient underwent a course of chemotherapy. 18F-FDG PET/CT was ordered again at the end of treatment showing partial response to therapy. He underwent radiation therapy to the site of residual disease, with complete metabolic response of lesions on follow up PET CT.

Objectives The change in tumor fluorodeoxyglucose (FDG) uptake by positron emission tomography (PET) scan after one cycle of platinum-based chemotherapy has been shown to predict progression-free and overall survival (PFS and OS) among advanced non-small cell lung cancer (NSCLC) patients. Using early FDG-PET response to determine subsequent chemotherapy, we aim to evaluate the role that adaptive chemotherapy regimens have on later CT response, PFS, and OS in patients with advanced NSCLC. Materials and Methods Chemotherapy-naïve patients with metastatic NSCLC received carboplatin and paclitaxel (CP) on day one and repeated FDG-PET on day 18. PET-responding patients continued CP chemotherapy for a total of four cycles. PET non-responders were switched to alternate docetaxel and gemcitabine (DG) for three additional cycles. The primary outcome was the CT Response Evaluation Criteria in Solid Tumors (RECIST 1.0) response. Secondary endpoints included PFS and OS. Results Forty-six patients initiated treatment with chemotherapy on trial and were evaluable by PET/CT. Of these, 19 (41%) met the FDG-PET criteria for the response after a single cycle of CP. Only one non-responding patient had a CT response. Despite the lack of CT response in the DG arm, no trend for worse PFS or OS was seen between the two arms. Conclusions This work demonstrates that changing chemotherapy in the event of non-response by PET did not lead to improved CT RECIST response. However, non-responding patients who switched chemotherapy had similar PFS and OS to those who responded by PET and continued the same regimen.

OBJECTIVE. Whole-body imaging extending from the vertex of the head to the toes is considered the standard 18F-FDG PET/CT protocol for Merkel cell carcinoma, though the evidence establishing this standard is scant. The purpose of this study was to investigate the clinical impact of PET/CT of the lower extremities in patients with Merkel cell carcinoma, a rare aggressive neuroendocrine tumor of the skin. MATERIALS AND METHODS. A total of 101 patients with Merkel cell carcinoma (mean age, 70.9 years) who underwent whole-body PET/CT were included. PET/CT findings in the lower extremities were evaluated on a per-patient basis, and the results were compared between patients with the primary lesion in the lower extremities (lower extremity primary) and those with the primary lesion located between the head and inguinal regions (body primary). Subsequent clinical evaluation and follow-up imaging were used as the reference standard. RESULTS. In the lower extremity (n = 22) and body (n = 79) primary groups, five and eight patients had true metastases in the lower extremities (p = .15). In the body primary group, all metastases in the lower extremities were part of widespread metastases in the body. In contrast, three of five patients (60%) in the lower extremity primary group had isolated metastases in the lower extremities, which differed significantly from the rate in the body primary group (p = .04). Subgroup analysis that included 48 patients who underwent initial staging examinations showed no metastases in the lower extremities regardless of primary location. CONCLUSION. PET/CT of the lower extremities for patients with body primary lesions of Merkel cell carcinoma should be considered of limited clinical utility.

1139 Objectives: Internal radiation therapies are usually personalized by treating to the dose limit of the patient’s main organ at risk (OAR). For Lu-177 DOTATATE, possible OAR are kidneys, bone marrow, liver and spleen, with kidneys the main OAR in a vast majority of patients. We previously introduced the concept of a personalized remote radiation tracking (PRRT) vest to enable customization of Lu-177 DOTATATE therapy for neuroendocrine tumor patients. The goal of the PRRT vest is to enable monitoring of the washout kinetics of Lu-177 DOTATATE from a patient’s OAR without requiring serial visits to a medical center. The monitoring would occur within the comfort of their own home. In this work, we seek to validate our PRRT software tools and personalized detector vest implementation through experimental testing using an in-house built anthropomorphic phantom, where our goal is to estimate washout kinetics for the kidneys within 5%. Methods: We fabricated a 25 cm diameter by 30 cm tall right circular cylinder phantom with anthropomorphic objects representing liver, spleen, right and left kidneys. The phantom inserts were 3D printed and had fill ports to allow additional activity to be added to the different structures without having to disassemble the phantom. A CT scan of the phantom was performed to register the 3D internal organs with a vest-like covering containing a CT visible grid wrapped around the phantom. Simulations were then run to determine the optimal placement of up to 12 small detectors to estimate the washout kinetics for each of the organs/background. A housing to situate 12 detectors around the cylinder was then created based upon the PRRT software results. Each detector was housed in a 14x14x14 mm^3 tungsten alloy box with 3 mm thick sides, an open back to place the sensor and a 4 mm pin-hole in the front plate. Each detector housed a 6x6x3 mm^3 crystal of GAGG coupled to a 6x6 mm^2 MPPC device. The right kidney, left kidney, liver, spleen and background compartments were filled sequentially, with relative activity concentrations of 20, 22, 4.5, 27, 2 for each object, respectively. For these initial experiments, Tc-99m was used in place of Lu-177. Data were collected from all of the sensors after each organ and the background were filled. The sensitivity map between each organ of interest/background and the 12 custom placed detectors was determined from the collected data. The half-lives for the washout kinetics for the right kidney, left kidney, liver, spleen and background were set to 48 hrs, 45 hrs, 65 hrs, 72 hrs and 97 hrs, respectively. Poisson sampling was used for accurate noise modeling of the collected counts for each organ and background. The composite signals for each of the 12 detectors over 21 days were then provided to our PRRT analysis software to estimate the washout kinetics of each individual organ and background from the composite detector signals. Results: Using data from 7, 14 or 21 days of measurements, the estimate of the half-life of the washout from each of the organs and background was always within 4%. Maximum error was 3.8% for the left kidney. Conclusions: Using an in-house built anthropomorphic phantom and our PRRT Vest software tools and experimental protocol, we were able to estimate the washout kinetics for the kidneys, liver, spleen and background to within 4% of the true decay rate for each of the organs of interest validating our simulation and PRRT vest methodologies.

Mid-chemoradiation PET imaging is prognostic for survival; PET response may be linked to tumor and peripheral immunologic biomarkers.

The 2019 novel coronavirus pneumonia (COVID-19) is an ongoing global pandemic with a worldwide death toll of over 416,000 as of June 10, 2020. Although the first documented cases in Wuhan, China were patients with severe respiratory symptoms including cough, fever, fatigue, and shortness of breath, the disease process can also be asymptomatic. In this case report, an asymptomatic 63-year-old male with Lynch syndrome undergoing a routine staging fluorodeoxyglucose positron-emission tomography/computed tomography was found to have typical radiologic features of COVID-19 with marked pulmonary FDG uptake and was subsequently diagnosed via reverse-transcription polymerase chain reaction. Many studies have described the appearance of COVID-19 on chest radiography and CT with the most common imaging features being bilateral, peripheral, and basilar predominant ground glass opacities and consolidation. Although these findings are typically nonspecific for an atypical lung infection, early recognition of COVID-19 in the setting of a global pandemic (even in the asymptomatic patient) is critical in order to limit the spread of disease.