Absence Of Emboli Research Articles

Association Between PD-L1 status Detected by SP142 and SP263 Antibody Clones and Clinical and Morphological Features of Gastric Cancer Factors

The aim is to study the relationship of PD-L1 status of SP142 and SP263 clones in gastric cancer with its clinical and morphological parameters. Material and methods. Surgical material obtained from 131 patients with a confirmed diagnosis of stomach cancer. Antibodies to PD-L1 SP263 were stained 127 cases, antibodies to PD-L1 SP142 – 126 cases. Reactions with PD-L1 were performed using the Ventana BenchMark Ultra device (Roche Ventana, USA) according to the protocols recommended by the manufacturer of primary antibodies. The results of immunohistochemical staining were compared with the clinical and morphological characteristics of gastric cancer using statistical analysis. Results. The positive PD-L1 status detected by clones SP263 and SP142 is significantly associated with type 2 macroscopic form according to the R. Bormann classification (p=0,003/p=0,003), tubular morphological type according to the WHO 5th edition, 2019 classification (p=0,001/p=0,018), intermediate morphological type according to the classification of P. Lauren (p=0,027/p=0,005) and the absence of signet ring cells (p=0,001/p=0,010). Staining with both clones used was not associated with the gender and age of patients, the size and localization of the tumor, the degree of its differentiation, the presence or absence of emboli in the lumen of blood and lymph vessels, the presence of affected lymph nodes and distant metastases, as well as the clinical stage (p>0,05). The largest proportion of PD-L1 positive cases in the study of SP263/SP142 clones was found in tubular type tumors (75,6%/84,6%) according to the WHO 5th edition, 2019 classification, intermediate type (60,0%/68,0%) according to P. Lauren, type 2 (65,4%/68,0%) according to R. Bormann and in the absence of signet ring cells (70,7%/76,9%). Conclusion. Statistically significant clinical and morphological parameters of gastric cancer, where a reliable relationship between them and the expression of PD-L1 clones SP263 and SP142 was revealed, are: type 2 macroscopic form according to R. Bormann (p=0,003/p=0,003), tubular morphological type according to the classification of WHO 5th edition, 2019) (p=0,001/p=0,018), intermediate type according to P. Lauren (p=0,027/p=0,005) and the absence of signet ring cells (p=0,001/p=0,010).

Blue toe syndrome caused by emboli from anomalous left atrial septal pouch thrombus: a case report

BackgroundLeft atrial septal pouches (LASPs) are a relatively newly described but common anatomical cardiac variant thought to be associated with atrial fibrillation (AF) and cardio-embolic stroke. Blue toe syndrome (BTS) describes ischemic changes in the toes due to microembolisation of the digital arteries. Establishing the etiology of BTS is vital so that the underlying cause can be treated. Here we describe the first case of BTS arising due to emboli from LASP thrombus arising on a background of new-onset AF.Case presentationA 65-year-old man presented with a two-day history of progressive painful swelling and bluish-purple discoloration of the second and fourth toes of his left foot and new-onset AF. Tests for hypercoagulability disorders were negative. Duplex ultrasound and CT angiography excluded deep venous thrombosis and an absence of embolus, thrombus, or occlusion in the arterial tree in the lower extremities bilaterally, so BTS was diagnosed. While transthoracic echocardiography and chest CT initially showed no cardiac abnormalities or mural thrombus, subsequent transesophageal echocardiography revealed a LASP with an associated pedunculated thrombus. The affected toes were amputated due to wet gangrene, but the patient recovered well with thrombus resolution after anticoagulation.ConclusionThe presence of a LASP in the absence of any other identifiable cause of BTS should trigger careful investigation of the interatrial septum, preferably using a multimodality imaging approach. The possibility that LASPs may not merely be an innocent bystander but a causative mechanism for peripheral ischemia must be considered.

Unusually Rapid Development of Pulmonary Hypertension and Right Ventricular Failure after COVID-19 Pneumonia.

COVID-19 is a novel viral disease caused by SARS-CoV-2. The mid- and long-term outcomes have not yet been determined. COVID-19 infection is increasingly being associated with systemic and multi-organ involvement, encompassing cytokine release syndrome and thromboembolic, vascular and cardiac events. The patient described experienced unusually rapid development of pulmonary hypertension (PH) and right ventricular failure after recent severe COVID-19 pneumonia with cytokine release syndrome, which initially was successfully treated with methylprednisolone and tocilizumab. The development of pulmonary hypertension and right ventricular failure – in the absence of emboli on multiple CT angiograms – was most likely caused by progressive pulmonary parenchymal abnormalities combined with microvascular damage of the pulmonary arteries (group III and IV pulmonary hypertension, respectively). To the best of our knowledge, these complications have not previously been described and therefore awareness of PH as a complication of COVID-19 is warranted.LEARNING POINTSCOVID-19 increasingly presents with systemic and multi-organ involvement with vascular, thromboembolic and cardiac events.Patients with severe COVID-19 pneumonia and concomitant cytokine release syndrome may be particularly at risk for the development of secondary pulmonary hypertension and right ventricular failure.Pulmonary hypertension can develop unusually rapidly following COVID-19 pneumonia and probably results from progressive pulmonary interstitial and microvascular abnormalities due to COVID-19.

How to train radiology residents to diagnose pulmonary embolism using a dedicated MRI protocol.

BackgroundIn recent years, magnetic resonance imaging (MRI) has been suggested as an alternative to computed tomography angiography (CTA) to diagnose pulmonary embolism (PE). In previous studies, only senior radiologists have been evaluated as reviewers.PurposeTo investigate if radiology residents can be trained to review MRI regarding PE and to determine the learning curve effects.Material and MethodsFour residents independently went through a training program consisting of 70 participants that had undergone steady-state free precession MRI. The individuals were randomized into ten training sessions. For each exam, the review time and presence or absence of embolus was recorded. After completing each session, the residents received feedback on diagnostic accuracy compared to a consensus reading by two specialists. The residents were also presented with the corresponding CTA.ResultsThe review time was nearly halved (P = 0.0002) during the training program. Comparing the first three sessions with the last three sessions for all residents, the review time decreased from 5:22 min to 2:51 min. The inter-reader agreement improved for all residents during the training program reaching a clinically acceptable level after seven sessions.ConclusionOur study suggests that radiology residents can be trained to independently review MRI investigations regarding PE within a short training program. Similar training programs could be more extensively used as effective teaching method for residents.

The value of dual-energy CT in diagnosing pulmonary embolism in children

Objective To evaluate the value of dual energy CT with Lung Vessels application in diagnosing pulmonary embolism (PE) of children. Methods Forty-seven patients with nephrotic syndrome and aged≤18 years old (32 male,15 female,mean age 15 years) underwent dual-energy CT pulmonary angiography (CTPA).Two radiologists recorded the presence or absence of emboli and counted the clots on a per-patient and per-lobe basis with Lung Vessels,respectively.With conventional CTPA as reference standard,sensitivity,specificity,positive predictive value (PPV),negative predictive value (NPV) of Lung Vessels application to detect PE were computed for two readers.Inter-reader agreement was also calculated. Results Conventional CTPA detected 51 clots in 35 lung lobes in 13 patients,giving PE incidence was 27.6% (13/47) for this cohort.On a per-patient basis,readers 1 and 2 detected 25 and 21 patients with PE with Lung Vessels,corresponding to sensitivities,specificities,PPVs,and NPVs of 100.0% (13/13),58.6% (17/29),43.3% (13/30),100.0% (17/17) and 100.0% (13/13),76.5% (21/29),50.0% (13/26),100.0% (21/21), Key words: Pulmonary embolism; Children; Nephrotic syndrome; Tomography,X-ray computed

Detection of Pulmonary Embolism: Comparison Between Dual Energy CT and MR Angiography in a Rabbit Model

The purpose of this study was to compare the efficacy of dual-energy computed tomography (DECT), time-resolved magnetic resonance (MR) imaging (MRI) perfusion measurements, and high-resolution MR angiography (MRA) for the detection of pulmonary embolism (PE) in a rabbit model. Two hours after Gelfoam (n = 16) or saline (n = 2) injection into the femoral vein, 18 rabbits were first imaged using dual-energy computed tomographic pulmonary angiography (CTPA), from which blood flow imaging (BFI) were produced. Next, the rabbits underwent time-resolved MR perfusion measurements and MRA using a 3.0-T scanner. Two radiologists who were blinded to histopathologic findings independently evaluated the results of CTPA, BFI, time-resolved MR perfusion, and MRA for each rabbit and recorded the locations and number of pulmonary clots on a per lobe basis. Immediately after MRI examination, pathologic determination of the locations and numbers of lung lobes with PE was recorded. Histopathologic results served as the reference standard to determine the sensitivity and specificity of DECT (BFI and CTPA) and MRI (time-resolved MR perfusion and high-resolution MRA) for the detection of PE. The induction of PE was successful in all animals, but three rabbits were excluded because of death prior to MRI procedures (caused by complications during the embolization procedure); only data from the remaining 15 rabbits were included in the final analysis. Histopathology demonstrated 24 lobes with clots and 51 lobes without clots. CTPA, BFI, and MRI correctly identified PE in 23, 23, and 20 lobes, respectively, and the absence of emboli in 48, 46, and 46 lobes, respectively; these results corresponded to sensitivities of 95.8%, 95.8%, and 83.3% and specificities of 94.1%, 90.2%, and 90.2% for reader 1 and sensitivities of 91.7%, 91.7%, and 87.5% and specificities of 90.2%, 88.2%, and 88.2% for reader 2 for CTPA, BFI, and MRI, respectively. Good or excellent intermodality and interreader agreement among CTPA, BFI, and MRI were found. DECT can simultaneously provide high-resolution pulmonary artery and lung iodine mapping with slightly high diagnostic accuracy for the detection of PE compared to MRI in an experimental rabbit model of PE. This improvement was not statistically significant given the study sample size.

Detection of pulmonary embolism by dual energy CT: correlation with perfusion scintigraphy and histopathological findings in rabbits

The purpose of the study was to compare the ability of dual energy CT (DECT) and perfusion scintigraphy (PS) to detect pulmonary embolism (PE) in a rabbit model. Gelfoam (n = 20) or saline (n = 4) was injected into the femoral vein of rabbits. After 2 h, DECT pulmonary angiography (CTPA) was used to create blood flow imaging (BFI) and fusion images. The rabbits then underwent PS. Pathological determination of locations and numbers of lung lobes with PE was recorded. The sensitivity and specificity for BFI, CTPA, fused images and PS were calculated using the pathological results as reference standards. Compared with pathological evaluation, CTPA correctly identified PE in 40 lobes and absence of emboli in 80 lobes, corresponding to a sensitivity and specificity of 100%. BFI and fused images correctly identified PE in 40 lobes and the absence of emboli in 78 lobes, corresponding to a sensitivity and specificity of 100% and 98%, respectively. PS correctly detected 27 lobes with PE and 65 lobes without PE, corresponding to a sensitivity and specificity of 68% and 81%, respectively. BFI, CTPA and fused images derived from a single contrast-enhanced DECT provide a higher diagnostic accuracy of detecting PE than PS in a rabbit model.

Pulmonary Embolism Detection with Dual-Energy CT: Experimental Study of Dual-Source CT in Rabbits

To evaluate feasibility and added value of dual-energy computed tomography (CT) in diagnosis of pulmonary embolism (PE). This institutional animal experimental committee-approved study was performed in accordance with animal care guidelines. Eight New Zealand rabbits underwent standard unenhanced and contrast material-enhanced dual-source CT. Gelatin sponge particles were injected into the pulmonary artery, and rabbits underwent contrast-enhanced dual-source CT pulmonary angiography, from which blood-flow (BF) and fusion images were created. Immediately after dual-source CT, rabbits were sacrificed, their lungs were removed and fixed in 10% formalin, and detailed pathologic determination of location and number of lung lobes with PE was performed. Two rabbits were excluded: One died during the procedure. In the other, the catheter tip was retained in the left inferior pulmonary artery. This caused marked postembolization CT image artifacts in adjacent regions. Six rabbits were included in final analysis. Two radiologists without knowledge of pathologic results evaluated five pulmonary lobes in each rabbit and recorded whether PE was present. Pathologic results served as the reference standard. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the techniques were calculated. Weighted kappa values were calculated to evaluate agreement between modalities. Pathologic analysis revealed PE in 18 of 30 pulmonary lobes. Conventional CT angiography was used to correctly identify PE in 12 lobes and absence of emboli in 18 lobes, which corresponded to sensitivity, specificity, PPV, and NPV of 67%, 100%, 100%, and 67%, respectively. A kappa value of 0.65 indicated good correlation with pathologic findings. On BF images, segments with an embolic region showed low perfusion compared with segments with a normal pulmonary region. BF images and fused images correctly showed PE in 16 of 18 pulmonary lobes and absence of emboli in 11 of 12 lobes, which corresponded to sensitivity, specificity, PPV, and NPV of 89%, 92%, 94%, and 85%, respectively, in detection of PE. A kappa value of 0.80 indicated good correlation with pathologic findings. Dual-source CT can depict normal and abnormal blood perfusion distribution in a rabbit's lung. Abnormal pulmonary blood distribution, as shown at dual-source CT, improves detection of acute PE in rabbits.

ECG-gated Multislice Spiral CT for Diagnosis of Acute Pulmonary Embolism

AIM: The purpose of this study was to determine the feasibility of echocardiogram (ECG)-gated multi-slice CT angiography (MCTA) in patients with clinical suspicion of acute venous thromboembolism (VTE), to investigate the effect of ECG-gating on cardiac motion artefacts, and to determine the diagnostic reader agreement of ECG-gated MCTA in comparison with conventional MCTA. MATERIALS AND METHODS: Forty-eight consecutive patients were prospectively enrolled and randomly underwent ECG-gated ( n=25, group 1) or non-ECG-gated ( n=23, group 2) eight-slice pulmonary MCTA. Image data were evaluated by three independent chest radiologists with respect to the presence or absence of emboli at different arterial levels (main, lobar, segmental, and subsegmental arteries), and with regard to cardiac motion artefacts. Statistical tests used to calculate inter-observer agreement were weighted κ statistics, extended κ statistics and confidence indices indicating three-reader agreement accuracy. RESULTS: Twenty-seven patients (56.3%) were diagnosed to have pulmonary embolism (13 from group 1, 14 from group 2). Cardiac motion artefacts were significantly more frequent in group 2 (70% in group 2 versus 13% in group 1, p=0.0001). The overall diagnostic agreement was excellent with both MCTA techniques (three-reader confidence index for all vascular territories: 0.76 and 0.84 for groups 1 and 2, respectively (extended κ=0.69 and 0.78, respectively); three-reader confidence index for diagnosis of VTE: 0.94 and 0.85 for groups 1 and 2, respectively (extended κ=0.91 and 0.73, respectively), weighted κ=0.81–0.83 and 0.92–0.95 for groups 1 and 2, respectively, and did not differ significantly between the two groups. In addition there was no significant difference of inter-observer agreement in either group at any assessed pulmonary arterial level. CONCLUSION: ECG-gated pulmonary MCTA is feasible in patients with clinical suspicion of VTE. However, ECG-gated image acquisition did not influence the diagnostic reader agreement accuracy and inter-observer agreement of MCTA. Hence, it does not appear to be advantageous for the MCTA diagnosis of pulmonary embolism.