MDCTA volumetric analysis for the quantification and grading of acute non-cerebral, non-gastrointestinal hemorrhage: a feasibility study.

PURPOSE: To assess the feasibility of multi-detector computed tomography angiography (MDCTA) volumetry for the quantification and grading of acute non-cerebral, non-gastrointestinal bleeding. METHODS: This retrospective, single-center study investigated consecutive patients with MDCTA positive for active non-cerebral, non-gastrointestinal bleeding, between January 2020 and June 2020. Outcome measures were the quantification of active extravasation at the arterial and parenchymal phase using volumetry measurements, the calculation of active bleeding rate and bleeding grading, 30-day mortality rate, identification of independent predictors of mortality and correlation between volumetric analysis, various clinical features, and the decision to proceed with an intervention. RESULTS: In total 30 patients (17 females; 56.6%; mean age 70.0 ± 16.0 years) were analyzed. Volumetric analysis was feasible in all cases resulting in excellent inter-observer variability (interclass correlation coefficient 0.999 for arterial and 0.919 for venous volume measurements). Mean volume of contrast extravasation was 1.06 ± 1.09 ml and 3.07 ± 2.48 ml at the arterial and parenchymal phases, respectively. Mean bleeding rate was 6.95 ± 7.82 ml/min. High bleeding volume at arterial phase (grade 4 bleeding) was the only independent predictor of 30-day mortality (HR 1383.58; p = 0.042). There was a positive correlation between bleeding volume at arterial phase (rs = 0.340; p = 0.033) and arterial bleeding rate (rs = 0.381; p = 0.019) with the decision to proceed with an intervention. Bleeding volume of 0.6 ml was the cutoff value for the prediction of intervention (sensitivity 96.3%; specificity 66.7%). CONCLUSIONS: MDCTA volumetric analysis for the quantification and grading of acute hemorrhage was feasible with excellent inter-observer agreement. The proposed bleeding grading system could optimize decision making and predict clinical outcomes.

Giant Pulmonary Artery Thrombotic Material, Due to Chronic Thromboembolic Pulmonary Hypertension, Mimics Pulmonary Artery Sarcoma.

In this article, we present the case of a 38-year-old female who suffered from serious respiratory distress. After an extensive pulmonary artery imaging diagnostic work-up (CTPA, MRA and PET), we were unable to differentiate between chronic thromboembolic pulmonary hypertension (CTEPH) vs. pulmonary artery sarcoma (PAS) due to extensive filling defects and extraluminal findings. Although surgery was postponed for nine months due to the COVID-19 pandemic, CTEPH diagnosis, due to a high-thrombus burden, was finally confirmed after pulmonary endarterectomy (PEA). Conclusively, imaging findings of rare cases of CTEPH might mimic PAS and the surgical removal of the lesion are both needed for a final diagnosis. What is Already Known about This Topic? Pulmonary artery sarcoma (PAS) is a rare but aggressive malignancy, which originates from the intimal layer of the pulmonary artery (PA); Chronic thromboembolic pulmonary hypertension (CTEPH) is based on chronic, organized flow-limiting thrombi inside PA circulation and subsequent pulmonary hypertension. What Does This Study Contribute? Since radiological findings of CTEPH cases might rarely mimic PAS, pulmonary artery endarterectomy and subsequent histopathologic study are needed for a final diagnosis.

Survival in Idiopathic pulmonary fibrosis acute exacerbations: the non-steroid approach.

BACKGROUND: Idiopathic pulmonary fibrosis acute exacerbation (IPF-AE) constitutes IPF's most devastating event, representing the unexpected superimposition of diffuse alveolar damage of unknown etiology. Guidelines recommend high-dose steroids treatment despite unproven benefit. We hypothesized that previous immunosuppression and the administration of high-dose steroids adversely affect IPF-AE outcome. METHODS: We studied all consecutive patients hospitalized in our department for IPF deterioration from 2007 to June 2013. Our protocol consisted of immediate cessation of immunosuppression (if any), best supportive care, broad-spectrum antimicrobials and thorough evaluation to detect reversible causes of deterioration. Patients were followed-up for survival; post-discharge none received immunosuppression. RESULTS: Twenty-four out of 85 admissions (28%) fulfilled IPF-AE criteria. IPF-AE were analyzed both as unique events and as unique patients. As unique events 50% survived; 3 out of 12 (25%) in the group previously treated with immunosuppression whereas nine out of 12 (75%) in the group not receiving immunosuppression (p = 0.041). As unique patients 35.3% survived; 3 out of 6 (50%) in the never treated group whereas three out of 11 (27.3%) in the group receiving immunosuppression (p = 0.685). The history of immunosuppression significantly and adversely influenced survival (p = 0.035). Survival was greater in the never treated group compared to the immunosuppressed patients (p = 0.022). Post-discharge, our IPF-AE survivors had an 83% 1-year survival. CONCLUSIONS: By applying the above mentioned protocol half of our patients survived. The history of immunosuppression before IPF-AE adversely influences survival. Avoiding steroids in IPF patients may favor the natural history of the disease even at the moment of its most devastating event.

"Luck's always to blame": silent wounds of a penetrating gunshot trauma sustained 20 years ago.

Gunshot tracheal injuries represent life-threatening events and usually necessitate emergent surgical intervention. We report a case of an exceptional finding of a patient with retained ballistic fragments in the soft tissues of the thorax, proximal to the right subclavian artery and the trachea, carrying silently his wounds for two decades without any medical or surgical intervention. The bullet pellet on the upper part of the trachea seen accidentally in the chest computed tomography, was also found during bronchoscopy. In short "luck's always to blame".

Introduction of an effective method for the optimization of CT protocols using iterative reconstruction algorithms: comparison with patient data.

OBJECTIVE: The purpose of this study is to introduce an efficient method for the optimization of iterative reconstruction CT protocols based on phantom image analysis and the comparison of obtained results with actual patient data. MATERIALS AND METHODS: We considered chest, abdomen, and pelvis CT examinations before the installation of an iterative reconstruction algorithm (iDose4) to define the exposure parameters used in clinical routine with filtered back projection (FBP). The body area of a CT phantom was subsequently scanned with various tube voltages and tube currents-exposure time products, and acquired data were reconstructed with FBP and different levels of iDose4. The contrast-to-noise ratio (CNR) for FBP with the original exposure parameters was calculated to define the minimum acceptable CNR value for each tube voltage. Then, an optimum tube current-exposure time products for each tube voltage and level of iterative reconstruction was estimated. We also compared findings derived by the phantom with real patient data by assessing dosimetric and image quality indexes from a patient cohort scanned with exposure parameters gradually adjusted during 1 year of adoption of iDose4. RESULTS: By use of the proposed phantom method, dose reduction up to 75% was achievable, whereas for an intermediate level of iteration (level 4), the dose reduction ranged between 50% and 60%, depending on the tube voltage. For comparison, with the gradual adjustment of exposure settings, the corresponding dose reduction for the same level of iteration was about 35%. CONCLUSION: The proposed method provides rapid and efficient optimization of CT protocols and could be used as the first step in the optimization process.

Effect of iDose4 iterative reconstruction algorithm on image quality and radiation exposure in prospective and retrospective electrocardiographically gated coronary computed tomographic angiography.

OBJECTIVES: The aims of this study were to compare a commercially available reconstruction algorithm (iDose4) with filtered back projection (FBP) in terms of image quality (IQ) for both retrospective electrocardiographically gated and prospective electrocardiographically triggered cardiac computed tomographic angiography (CCTA) protocols and to evaluate the achievable radiation dose reduction. METHODS: A total cohort of 58 patients underwent either prospective CTCA or retrospective CTCA with full or reduced tube current-time product (in milliampere-second) protocol on a 64-slice multidetector computed tomographic scanner. All images were reconstructed with FBP, whereas the reduced milliampere-second images were also reconstructed using 2 levels (levels 4 and 6) of iDose4. Subjective and objective IQ was evaluated. RESULTS: Dose reductions of 43% in the retrospective CCTA protocol and 27% in the prospective CCTA protocol were achieved without compromising IQ. In the prospective CCTA protocol, the reduced-dose images were highly scored; thus, additional reduction of exposure settings is feasible. In the retrospective acquisition, dose reduction has led to similar IQ scores between the reduced-dose iDose4 images and the full-dose FBP images. Considering different reconstructions (FBP, iDose-L4 and -L6) of the same acquisition data, increase in iDose4 level resulted in less noisy images. A slight improvement was also noticed in all IQ indices; however, this improvement was not statistically significant for both acquisition protocols. CONCLUSIONS: This study demonstrated that the application of iDose at CCTA facilitates significant radiation dose reduction by maintaining diagnostic quality. The combination of iDose4 with prospective acquisition is able to significantly reduce effective dose associated with CTCA at values of approximately 2 mSv and even lower.

A new era in computed tomographic dose optimization: the impact of iterative reconstruction on image quality and radiation dose.

The ongoing evolution of computer technology has made the use of iterative reconstruction (IR) algorithms clinically applicable. We reviewed current literature on the clinical use of IR against filtered back projection algorithms in terms of image quality and radiation dose. Iterative reconstruction algorithms provide equal or better image quality compared with filtered back projection, with dose reduction ranging from 25% to 98.6%. However, several studies have reported that the superior results of IR regarding objective evaluation are not always favorably interpreted by radiologists. Further clinical evaluation is needed to certify the optimal tradeoff between imaging quality and radiation dose, and radiologists need to become more familiar with the new appearance of computed tomographic images.

Ovarian hyperstimulation syndrome complicated by severe community-acquired pneumonia due to methicillin-resistant Staphylococcus aureus positive for Panton-Valentine leukocidin.

We report a case of severe ovarian hyperstimulation syndrome (OHSS) complicated by community-acquired methicillin-resistant Staphylococcus aureus-Panton-Valentine leukocidin positive (CAMRSA-PVL[+]) necrotizing pneumonia, sepsis and multiple organ failure (MOF) in a previously immunocompetent female. The patient required prolonged ventilatory support and intensive care unit (ICU) hospitalization. Multiple cavities and severely affected lung function persist 1 year after discharge.

Lung cancer histology classification from CT images based on radiomics and deep learning models.

Adenocarcinoma (AC) and squamous cell carcinoma (SCC) are frequent reported cases of non-small cell lung cancer (NSCLC), responsible for a large fraction of cancer deaths worldwide. In this study, we aim to investigate the potential of NSCLC histology classification into AC and SCC by applying different feature extraction and classification techniques on pre-treatment CT images. The employed image dataset (102 patients) was taken from the publicly available cancer imaging archive collection (TCIA). We investigated four different families of techniques: (a) radiomics with two classifiers (kNN and SVM), (b) four state-of-the-art convolutional neural networks (CNNs) with transfer learning and fine tuning (Alexnet, ResNet101, Inceptionv3 and InceptionResnetv2), (c) a CNN combined with a long short-term memory (LSTM) network to fuse information about the spatial coherency of tumor's CT slices, and (d) combinatorial models (LSTM + CNN + radiomics). In addition, the CT images were independently evaluated by two expert radiologists. Our results showed that the best CNN was Inception (accuracy = 0.67, auc = 0.74). LSTM + Inception yielded superior performance than all other methods (accuracy = 0.74, auc = 0.78). Moreover, LSTM + Inception outperformed experts by 7-25% (p < 0.05). The proposed methodology does not require detailed segmentation of the tumor region and it may be used in conjunction with radiological findings to improve clinical decision-making. Lung cancer histology classification from CT images based on CNN + LSTM.

Patient radiation exposure measurements during interventional procedures: a prospective study.

This is a prospective study with the purpose of assessing patient radiation dose and stochastic risk (risk for fatal cancer) in a patient population undergoing interventional radiological (IR) procedures. Measurements were performed on 36 consecutive patients undergoing percutaneous transluminal angioplasty (PTA, n=18), transjugular intrahepatic portosystemic shunt (TIPS, n=3), diagnostic angiography (DA, n=6), arterial embolization (AE, n=3), and hepatic neoplasm chemoembolization (HCE, n=6). Kerma area product (KAP) was used as a measure of x-ray exposure to the patient. Mean KAP value per procedure was 79+/-50 Gy cm for PTA, 139+/-55 Gy cm for TIPS, 110+/-44 Gy cm for DA, 325+/-145 Gy cm for AE, and 150+/-76 Gy cm for HCE. Forty-six percent of total KAP value was attributed to fluoroscopy. In conclusion, we showed that a linear correlation between effective dose and KAP was found (r=0.84), which could be used for estimating patient effective dose using KAP measurements. Small changes to the number of digital frames acquired result in substantial change of the total KAP in interventional radiological procedures. Stochastic risk from IR procedures is quite low for the patient. Measuring KAP is a simple and accurate method, which provides the interventional radiologist with a good estimation of the patient's relative risk for stochastic effects.

Patient radiation exposure and image quality evaluation with the use of iDose4 iterative reconstruction algorithm in chest-abdomen-pelvis CT examinations.

The aim of this study is to evaluate the effect of iDose(4) iterative reconstruction algorithm on radiation dose and imaging quality at chest-abdomen-pelvis (CAP) CT examinations. Seventeen patients were considered; all patients had a previous CT scan with the standard filter back-projection (FBP) protocol and a follow-up scan with the iDose(4) protocol at the same scanner. Image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were objectively calculated. Two radiologists evaluated noise, sharpness, contrast, diagnostic confidence and artefacts. Radiation exposure quantities were calculated. iDose(4) resulted in 46 % dose reduction combined with significantly lower noise and higher SNR and CNR compared with FBP. iDose(4) images had significantly lower subjective image noise and enhanced sharpness and contrast. Diagnostic confidence was high and image artefacts were minor for both algorithms. iDose(4) provides great potential for reducing patient radiation burden while improving imaging quality in CAP CT examinations.

Radiation dose and image noise evaluation in coronary computed tomography angiography (CCTA) using an iterative reconstruction algorithm.

INTRODUCTION: The purpose of this study was to evaluate radiation dose reduction in coronary computerised tomography angiography (CCTA), using a commercially available iterative reconstruction (IR) algorithm as well as the behaviour of the image noise. METHODS: A total cohort of 47 patients underwent CCTA examination on a 64-slice multi-detector CT. They were divided into four groups according to the time when the examination was performed (before or after the installation of iDose) and the acquisition protocol followed (prospective or retrospective electrocardiography-ECG gated). The images acquired with reduced dose settings were reconstructed using two levels (L4 and L6) of the iDose4 algorithm. Image noise was measured in all cases. RESULTS: In retrospective acquisition, images acquired with a 46% lower radiation dose and reconstructed with iDose4 L6 provided noise comparable to that in the full-dose filtered back-projection images. For the prospective acquisition mode, a slight decrease (26%) in radiation dose resulted in noise improvement in low-dose images reconstructed with iDose4 L4 (16% noise removal) and L6 (30% noise removal). CONCLUSIONS: The fact that image quality is improved while radiation exposure is reduced indicates that there is room for a further reduction in exposure settings. Additionally, the combination of iDose4 with prospective acquisition is able to significantly reduce the radiation dose associated with CCTA at values of about 2 mSv and even lower.

Implications of the Incidental Finding of a MYCN Amplified Adrenal Tumor: A Case Report and Update of a Pediatric Disease Diagnosed in Adults.

MYCN is a well-known oncogene overexpressed in different human malignancies including neuroblastoma, rhabdomyosarcoma, medulloblastoma, astrocytoma, Wilms' tumor, and small cell lung cancer. While neuroblastoma is one of the most common childhood malignancies, in adults it is extremely rare and its treatment is based on pediatric protocols that take into consideration stage and genotypic features, such as MYCN amplification. Although neuroblastoma therapy has evolved, identification of early stage patients who need chemotherapy continues to pose a therapeutic challenge. The emerging prognostic role of MYCN phenotype of this disease is currently under investigation as it may redefine MYCN amplified subgroups. We describe an unusual case of adult neuroblastoma with MYCN amplification diagnosed incidentally and discuss possible therapeutic dilemmas.

Bright-dark ring sign in MR imaging of hepatic epithelioid hemangioendothelioma.

We describe the imaging findings in a rare case of multifocal nodular form of hepatic epithelioid hemangioendothelioma on ultrasound (US) and dynamic contrast-enhanced spiral computed tomography (CT) and MRI. The nodules showed multilayered target appearance on MR images with prominent peripheral rim with high signal intensity (SI) on T1-weighted and very low SI on T2-weighted images, corresponding to thrombosed vascular channels. The above combination of imaging findings is to our knowledge distinct and should suggest the diagnosis of hepatic epithelioid hemangioendothelioma.