Summary
Objectives
Patients with acute respiratory distress syndrome (ARDS) due to viral infection are at risk for secondary complications like invasive aspergillosis. Our study evaluates coronavirus ...disease 19 (COVID‐19) associated invasive aspergillosis at a single centre in Cologne, Germany.
Methods
A retrospective chart review of all patients with COVID‐19 associated ARDS admitted to the medical or surgical intensive care unit at the University Hospital of Cologne, Cologne, Germany.
Results
COVID‐19 associated invasive pulmonary aspergillosis was found in five of 19 consecutive critically ill patients with moderate to severe ARDS.
Conclusion
Clinicians caring for patients with ARDS due to COVID‐19 should consider invasive pulmonary aspergillosis and subject respiratory samples to comprehensive analysis to detect co‐infection.
We sought to investigate the clinical response to MET inhibition in patients diagnosed with structural MET alterations and to characterize their functional relevance in cellular models.
Patients were ...selected for treatment with crizotinib upon results of hybrid capture-based next-generation sequencing. To confirm the clinical observations, we analyzed cellular models that express these MET kinase alterations.
Three individual patients were identified to harbor alterations within the MET receptor. Two patients showed genomic rearrangements, leading to a gene fusion of
or
and
One patient diagnosed with an EML4-ALK rearrangement developed a MET kinase domain duplication as a resistance mechanism to ceritinib. All 3 patients showed a partial response to crizotinib that effectively inhibits MET and ALK among other kinases. The results were further confirmed using orthogonal cellular models.
Crizotinib leads to a clinical response in patients with MET rearrangements. Our functional analyses together with the clinical data suggest that these structural alterations may represent actionable targets in lung cancer patients.
.
Objectives
To investigate the robustness of radiomic features between three dual-energy CT (DECT) systems.
Methods
An anthropomorphic body phantom was scanned on three different DECT scanners, a ...dual-source (dsDECT), a rapid kV-switching (rsDECT), and a dual-layer detector DECT (dlDECT). Twenty-four patients who underwent abdominal DECT examinations on each of the scanner types during clinical follow-up were retrospectively included (
n
= 72 examinations). Radiomic features were extracted after standardized image processing, following ROI placement in phantom tissues and healthy appearing hepatic, splenic and muscular tissue of patients using virtual monoenergetic images at 65 keV (VMI
65keV
) and virtual unenhanced images (VUE). In total, 774 radiomic features were extracted including 86 original features and 8 wavelet transformations hereof. Concordance correlation coefficients (CCC) and analysis of variances (ANOVA) were calculated to determine inter-scanner robustness of radiomic features with a CCC of ≥ 0.9 deeming a feature robust.
Results
None of the phantom-derived features attained the threshold for high feature robustness for any inter-scanner comparison. The proportion of robust features obtained from patients scanned on all three scanners was low both in VMI
65keV
(dsDECT vs. rsDECT:16.1% (125/774), dlDECT vs. rsDECT:2.5% (19/774), dsDECT vs. dlDECT:2.6% (20/774)) and VUE (dsDECT vs. rsDECT:11.1% (86/774), dlDECT vs. rsDECT:2.8% (22/774), dsDECT vs. dlDECT:2.7% (21/774)). The proportion of features without significant differences as per ANOVA was higher both in patients (51.4–71.1%) and in the phantom (60.6–73.4%).
Conclusions
The robustness of radiomic features across different DECT scanners in patients was low and the few robust patient-derived features were not reflected in the phantom experiment. Future efforts should aim to improve the cross-platform generalizability of DECT-derived radiomics.
Key Points
•
Inter-scanner robustness of dual-energy CT-derived radiomic features was on a low level in patients who underwent clinical examinations on three DECT platforms.
•
The few robust patient-derived features were not confirmed in our phantom experiment.
•
Limited inter-scanner robustness of dual-energy CT derived radiomic features may impact the generalizability of models built with features from one particular dual-energy CT scanner type
Objectives
Dual-energy computed tomography allows for an accurate and reliable quantification of iodine. However, data on physiological distribution of iodine concentration (IC) is still sparse. This ...study aims to establish guidance for IC in abdominal organs and important anatomical landmarks using a large cohort of individuals without radiological tumor burden.
Methods
Five hundred seventy-one oncologic, portal venous phase dual-layer spectral detector CT studies of the chest and abdomen without tumor burden at time point of imaging confirmed by > 3-month follow-up were included. ROI were placed in parenchymatous organs (
n
= 25), lymph nodes (
n
= 6), and vessels (
n
= 3) with a minimum of two measurements per landmark. ROI were placed on conventional images and pasted to iodine maps to retrieve absolute IC. Normalization to the abdominal aorta was conducted to obtain iodine perfusion ratios. Bivariate regression analysis,
t
tests, and ANOVA with Tukey-Kramer post hoc test were used for statistical analysis.
Results
Absolute IC showed a broad scatter and varied with body mass index, between different age groups and between the sexes in parenchymatous organs, lymph nodes, and vessels (range 0.0 ± 0.0 mg/ml–6.6 ± 1.3 mg/ml). Unlike absolute IC, iodine perfusion ratios did not show dependency on body mass index; however, significant differences between the sexes and age groups persisted, showing a tendency towards decreased perfusion ratios in elderly patients (e.g., liver 18–44 years/≥ 64 years: 0.50 ± 0.11/0.43 ± 0.10,
p
≤ 0.05).
Conclusions
Distribution of IC obtained from a large-scale cohort is provided. As significant differences between sexes and age groups were found, this should be taken into account when obtaining quantitative iodine concentrations and applying iodine thresholds.
Key Points
•
Absolute iodine concentration showed a broad variation and differed between body mass index, age groups, and between the sexes in parenchymatous organs, lymph nodes, and vessels.
•
The iodine perfusion ratios did not show dependency on body mass index while significant differences between sexes and age groups persisted.
•
Provided guidance values may serve as reference when aiming to differentiate healthy and abnormal tissue based on iodine perfusion ratios.
iRECIST: how to do it Persigehl, Thorsten; Lennartz, Simon; Schwartz, Lawrence H
Cancer imaging,
01/2020, Letnik:
20, Številka:
1
Journal Article
Recenzirano
Odprti dostop
iRECIST for the objective monitoring of immunotherapies was published by the official RECIST working group in 2017.
Immune-checkpoint inhibitors represent one of the most important therapy ...advancements in modern oncology. They are currently used for treatment of multiple malignant diseases especially at advanced, metastatic stages which were poorly therapeutically accessible in the past. Promising results of recent studies suggest that their application will further grow in the near future, particularly when used in combination with chemotherapy. A challenging aspect of these immunotherapies is that they may show atypical therapy response patterns such as pseudoprogression and demonstrate a different imaging spectrum of adverse reactions, both of which are crucial for radiologists to understand. In 2017 the RECIST working group published a modified set of response criteria, iRECIST, for immunotherapy, based on RECIST 1.1 which was developed for cytotoxic therapies and adapted for targeted agents.
This article provides guidance for response assessment of oncologic patients under immunotherapy based on iRECIST criteria.
Dual-energy CT allows for the reconstruction of virtual non-contrast (VNC) images. VNC images have the potential to replace true non-contrast scans in various clinical applications. This study ...investigated the quantitative accuracy of VNC attenuation images considering different parameters for acquisition and reconstruction. An abdomen phantom with 7 different tissue types (different combinations of 3 base materials and 5 iodine concentrations) was scanned using a spectral detector CT (SDCT). Different phantom sizes (S, M, L), volume computed tomography dose indices (CTDIvol 10, 15, 20 mGy), kernel settings (soft, standard, sharp), and denoising levels (low, medium, high) were tested. Conventional and VNC images were reconstructed and analyzed based on regions of interest (ROI). Mean and standard deviation were recorded and differences in attenuation between corresponding base materials and VNC was calculated (VNCerror). Statistic analysis included ANOVA, Wilcoxon test and multivariate regression analysis. Overall, the VNC
was - 1.4 ± 6.1 HU. While radiation dose, kernel setting, and denoising level did not influence VNC
significantly, phantom size, iodine content and base material had a significant effect (e.g. S vs. M: - 1.2 ± 4.9 HU vs. - 2.1 ± 6.0 HU; 0.0 mg/ml vs. 5.0 mg/ml: - 4.0 ± 3.5 HU vs. 5.1 ± 5.0 HU and 35-HU-base vs. 54-HU-base: - 3.5 ± 4.4 HU vs. 0.7 ± 6.5; all p ≤ 0.05). The overall accuracy of VNC images from SDCT is high and independent from dose, kernel, and denoising settings; however, shows a dependency on patient size, base material, and iodine content; particularly the latter results in small, yet, noticeable differences in VNC attenuation.
Deciphering the evolution of cancer cells under therapeutic pressure is a crucial step to understand the mechanisms that lead to treatment resistance. To this end, we analyzed whole-exome sequencing ...data of eight chronic lymphocytic leukemia (CLL) patients that developed resistance upon BCL2-inhibition by venetoclax. Here, we report recurrent mutations in BTG1 (2 patients) and homozygous deletions affecting CDKN2A/B (3 patients) that developed during treatment, as well as a mutation in BRAF and a high-level focal amplification of CD274 (PD-L1) that might pinpoint molecular aberrations offering structures for further therapeutic interventions.
•Obesity and body composition determined in initial LDCT is a risk factor for SARS‐CoV‐2 infected patients.•An initial LDCT can be used to screen opportunistically for obese COVID-19 ...patients.•Unfavorable body composition is associated with increased risk for the need of intensive care treatment.
Low-dose computed tomography (LDCT) of the chest is a recommended diagnostic tool in early stage of COVID-19 pneumonia. High age, several comorbidities as well as poor physical fitness can negatively influence the outcome within COVID-19 infection. We investigated whether the ratio of fat to muscle area, measured in initial LDCT, can predict severe progression of COVID-19 in the follow-up period.
We analyzed 58 individuals with confirmed COVID-19 infection that underwent an initial LDCT in one of two included centers due to COVID-19 infection. Using the ratio of waist circumference per paravertebral muscle circumference (FMR), the body composition was estimated. Patient outcomes were rated on an ordinal scale with higher numbers representing more severe progression or disease associated complications (hospitalization/ intensive care unit (ICU)/ tracheal intubation/ death) within a follow-up period of 22 days after initial LDCT.
In the initial LDCT a significantly higher FMR was found in patients requiring intensive care treatment within the follow-up period. In multivariate logistic regression analysis, FMR (p < .001) in addition to age (p < .01), was found to be a significant predictor of the necessity for ICU treatment of COVID-19 patients.
FMR as potential surrogate of body composition and obesity can be easily determined in initial LDCT of COVID-19 patients. Within the multivariate analysis, in addition to patient age, low muscle area in proportion to high fat area represents an additional prognostic information for the patient outcome and the need of an ICU treatment during the follow-up period within the next 22 days.
This multicentric pilot study presents a method using an initial LDCT to screen opportunistically for obese patients who have an increased risk for the need of ICU treatment. While clinical capacities, such as ICU beds and ventilators, are more crucial than ever to help manage the current global corona pandemic, this work introduces an approach that can be used for a cost-effective way to help determine the amount of these rare clinical resources required in the near future.
Background
Decreasing MRI scan time is a key factor to increase patient comfort and compliance as well as the productivity of MRI scanners.
Purpose/Hypothesis
Compressed sensing (CS) should ...significantly accelerate 3D scans. This study evaluated the clinical application and cost effectiveness of accelerated 3D T2 sequences of the lumbar spine.
Study Type
Prospective, cross‐sectional, observational.
Population
Twenty healthy volunteers and 10 patients.
Field Strength/Sequence
A 3D T2 TSE sequence, identical 3D sequences with three different parallel imaging and CS accelerating factors, and 2D TSE sequences as a clinical reference were obtained on a 3T scanner.
Assessment
Three readers evaluated the sequences for delineation of anatomical structures and image quality. A quantitative analysis consisting of root mean square error, structural similarity index, signal‐to‐noise ratio, and contrast‐to‐noise ratio were performed. The scan times were used to calculate cost differences for each sequence.
Statistical Tests
An analysis of variance with repeated measurements and the Friedman test were used to test for potential differences between the sequences. Post‐hoc analysis was made with the chi‐squared and Tukey–Kramer test.
Results
CS with factor 4.5 results in unchanged image quality compared to the T2 TSE for volunteers and patients (overall image impression: 4.75 vs. 4.20 P = 0.73 and 4.90 vs. 4.47 P = 0.44). The CS 4.5 scan is 167 seconds (–39%) faster than the 3D and 216.5 seconds (–45%) faster than the 2D sequences. No significant differences was found for the diagnostic certainty in the volunteers and patients between 2D TSE and 3D CS 4.5 (P = 0.89 and P = 0.43). A reduction of scan time to 148 seconds (CS 8) was still rated acceptable for most diagnosis.
Data Conclusion
CS accelerates the 3D T2 without compromising image quality. The 3D sequences offer comparable diagnostic quality to the clinical 2D standard with less scan time (–45%), potentially increasing the productivity of MRI scanners.
Level of Evidence: 1
Technical Efficacy: Stage 6 J. Magn. Reson. Imaging 2019;49:e164–e175.
To evaluate artifact reduction by virtual monoenergetic images (VMI) and metal artifact reduction algorithms (MAR) as well as the combination of both approaches (VMI
) compared to conventional CT ...images (CI) as standard of reference. In this retrospective study, 35 patients were included who underwent spectral-detector CT (SDCT) with additional MAR-reconstructions due to artifacts from coils or clips. CI, VMI, MAR and VMI
(range: 100-200 keV, 10 keV-increment) were reconstructed. Region-of-interest based objective analysis was performed by assessing mean and standard deviation of attenuation (HU) in hypo- and hyperdense artifacts from coils and clips. Visually, extent of artifact reduction and diagnostic assessment were rated. Compared to CI, VMI ≥ 100 keV, MAR and VMI
between 100-200 keV increased attenuation in hypoattenuating artifacts (CI/VMI
/MAR/VMI
, HU: -77.6 ± 81.1/-65.1 ± 103.2/-36.9 ± 27.7/-21.1 ± 26.7) and decreased attenuation in hyperattenuating artifacts (HU: 47.4 ± 32.3/42.1 ± 50.2/29.5 ± 18.9/20.8 ± 25.8). However, differences were only significant for MAR in hypodense and VMI
in hypo- and hyperdense artifacts (p < 0.05). Visually, hypo- and hyperdense artifacts were significantly reduced compared to CI by VMI
, MAR and VMI
. Diagnostic assessment of surrounding brain tissue was significantly improved in VMI
, MAR and VMI
. The combination of VMI and MAR facilitates a significant reduction of artifacts adjacent to intracranial coils and clips. Hence, if available, these techniques should be combined for optimal reduction of artifacts following intracranial aneurysm treatment.
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