Computed Tomography Pulmonary Angiography Research Articles

Distribution of thrombus predicts severe reperfusion pulmonary edema after pulmonary endarterectomy

ObjectivesPatients underwent pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed to investigate the effect of thrombus distribution on the occurrence of severe reperfusion pulmonary edema (RPE) and identify specific parameters for predicting severe RPE. MethodsPatients with CTEPH who underwent PEA surgery were retrospectively analyzed. The thrombus in pulmonary arteries were evaluated through computed tomography pulmonary angiography. Based on presence of prolonged artificial ventilation, extracorporeal membrane oxygenation required, or perioperative death due to RPE, the patients were divided into the severe RPE and without severe RPE groups. Main resultsAmong the 77 patients (29 women), 16 (20.8%) patients developed severe RPE. The right major pulmonary artery (RPA) (0.64[0.58, 0.73] vs 0.58[0.49, 0.64]; p = 0.008) and pulmonary artery trunk (PAT) thrombus ratios (0.48[0.44, 0.61] vs 0.42[0.39, 0.50]; p = 0.009) (the PAT ratio is expressed as the sum of the right middle lobe clot burden and right lower lobe clot burden divided by the total clot burden multiplied by 100) of the severe RPE group was significantly higher than that of the without severe RPE group. Receiver operator characteristics curve identified a PAT ratio of 43.4% as the threshold with areas under the curve = 0.71(95%CI 0.582; 0.841) for the development of severe RPE (sensitivity 0.875, specificity 0.541). The logistic regression analysis demonstrated that age, period from symptom onset to PEA, NT-pro BNP, preoperative mPAP, preoperative PVR, RPA ratio, and PAT ratio were associated with the development of severe RPE. Multivariable logistic regression analysis revealed PAT ratio (odds ratio = 10.2; 95% confidence interval 1.87, 55.53, P = 0.007) and period from symptom onset to PEA (OR = 1.01; 95% CI = 1.00–1.02, P = 0.015) as independent risk factors for the development of severe RPE. ConclusionsThe thrombus distribution could be a key factor in the severity of RPE. PAT ratio and medical history could predict the development of severe RPE.

Systematic screening versus clinical gestalt in the diagnosis of pulmonary embolism in COVID-19 patients in the emergency department.

Diagnosing concomitant pulmonary embolism (PE) in COVID-19 patients remains challenging. As such, PE may be overlooked. We compared the diagnostic yield of systematic PE-screening based on the YEARS-algorithm to PE-screening based on clinical gestalt in emergency department (ED) patients with COVID-19. We included all ED patients who were admitted because of COVID-19 between March 2020 and February 2021. Patients already receiving anticoagulant treatment were excluded. Up to April 7, 2020, the decision to perform CT-pulmonary angiography (CTPA) was based on physician's clinical gestalt (clinical gestalt cohort). From April 7 onwards, systematic PE-screening was performed by CTPA if D-dimer level was ≥1000 ug/L, or ≥500 ug/L in case of ≥1 YEARS-item (systematic screening cohort). 1095 ED patients with COVID-19 were admitted. After applying exclusion criteria, 289 were included in the clinical gestalt and 574 in the systematic screening cohort. The number of PE diagnoses was significantly higher in the systematic screening cohort compared to the clinical gestalt cohort: 8.2% vs. 1.0% (3/289 vs. 47/574; p<0.001), even after adjustment for differences in patient characteristics (adjusted OR 8.45 (95%CI 2.61-27.42, p<0.001) for PE diagnosis). In multivariate analysis, D-dimer (OR 1.09 per 1000 μg/L increase, 95%CI 1.06-1.13, p<0.001) and CRP >100 mg/L (OR 2.78, 95%CI 1.37-5.66, p = 0.005) were independently associated with PE. In ED patients with COVID-19, the number of PE diagnosis was significantly higher in the cohort that underwent systematic PE screening based on the YEARS-algorithm in comparison with the clinical gestalt cohort, with a number needed to test of 7.1 CTPAs to detect one PE.

Positive rate and quality assessment of CT pulmonary angiography in sickle cell disease: a case‒control study.

Pulmonary complications are common in sickle cell disease (SCD) and can mimic pulmonary embolisms (PEs), leading to potential overuse of computed tomography pulmonary angiography (CTPA). Maximizing the quality of CTPA is essential for its diagnostic accuracy. However, little is known about the positive rate and quality of CTPA in SCD. This retrospective case‒control study aimed to determine the positive rate and quality of CTPA studies performed to rule out PE in SCD (HbSS genotype) patients compared to a control group. Logistic regression analysis was used to identify independent factors associated with suboptimal CTPA studies, defined as a mean enhancement of < 210 HU in the pulmonary artery. The study included 480 patients, consisting of 240 SCD patients and 240 controls. The positive rate of PE was 4.0%, with a similar rate in both SCD patients and the control group (4.2% vs. 3.8%, p = 0.08). However, SCD patients had significantly lower contrast enhancement of the pulmonary artery than the control group (266.1 ± 90.5 HU vs. 342.2 ± 116.1 HU, p < 0.01). Notably, 25.4% of SCD patients had suboptimal scans. The logistic regression model demonstrated that SCD was significantly associated with suboptimal pulmonary arterial contrast enhancement compared to the control group (OR = 4.4; 95% CI: 2.4-8.3). This study revealed a relatively low positive rate of CTPA in both SCD patients and the control group. However, SCD was significantly associated with suboptimal image quality due to inadequate contrast enhancement of the pulmonary artery. Further research is needed to identify measures that can enhance the quality of CTPA studies in SCD patients and to establish a specific imaging protocol for this patient population.

Major Pulmonary Arterial Hypertension Secondary to Congenital Portosystemic Intra Hepatic Shunt: A Case Report

Congenital portosystemic shunt, also known as Abernethy malformation, is a rare vascular malformation in which the portal blood drains towards the systemic circulation eluding the liver. These shunts arise through disturbances that intervene in the embryonic development of the splanchnic circulation, or when elements that are specific to the fetal circulation (especially those regarding the ductus venous) persist beyond the intrauterine life. We present the case of an 23 men years old, followed for ventricular septal defect (VSD) and pulmonary hypertension (PHA), who was addressed to our department to realize a Computed tomography pulmonary angiography (CTPA) for suspicion an acute pulmonary embolism (APE) due to a high d-dimer level. This examination does not show direct or indirect signs of pulmonary embolism but on the other hand objective a major pulmonary arterial hypertension associated with cardiomegaly secondary to a portosystemic intrahepatic shunt. An abdominal CT scan was requested in order to detail this vascular malformation and to objectify the presence of the portal trunk by the confluence of the spleno-mesaraic trunk and the inferior mesenteric vein with the demonstration of the communication of the right portal branch with inferior vena cava. Angio-CT should be the performed whenever a vascular malformation is suspected in order to establish a correct diagnosis, because portosystemic shunts carry a high risk of severe complications.

ASSESSMENT OF INCIDENCE OF PULMONARY EMBOLISM IN COVID-19 PATIENTS: A SINGLE-CENTER STUDY

Pulmonary embolism (PE) is a life-threatening disease with a high death toll. Recent research has shown that patients with COVID-19 are more likely to experience PE because of the inflammatory reaction and hypercoagulability. This article's goal is to assess the prevalence of PE among hospitalized COVID-19 patients. We examined the medical files of 210 individuals hospitalized in the COVID-19 unit at Bahria Town International Hospital Lahore between September 1, 2020, and September 30, 2021. Real-time polymerase chain reaction was used to identify COVID-19 in the patients and computed tomography pulmonary angiography (CTPA) was performed to ascertain PE. Of the 210 patients, 9 experienced PE, constituting a 4.3% incidence rate in our study. Our research demonstrates that PE frequently occurs in COVID-19 hospitalized patients. Based on the results, it can be concluded that preventive measures should be considered for people with COVID-19 disease, especially those with a smoking history and low oxygen levels. The fatality rates linked to this illness can be decreased by early diagnosis and timely treatment.

Diagnostic approach and use of CTPA in patients with suspected pulmonary embolism in an emergency department in Saudi Arabia.

In patients with suspected pulmonary embolism (PE), the literature suggests the overuse of computerized tomography pulmonary angiography (CTPA) and underuse of clinical decision rules before imaging request. This study determined the potential for avoidable CTPA using the modified Wells score (mWS) and D-dimer assay in patients with suspected PE. This hospital-based retrospective study analyzed the clinical data of 661 consecutive patients with suspected PE who underwent CTPA in the emergency department of a tertiary hospital for the use of a clinical prediction rule (mWS) and D-dimer assay. The score was calculated retrospectively from the available data in the files of patients who did not have a documented clinical prediction rule. Overuse (avoidable) CTPA was defined as D-dimer negativity and PE unlikely for this study. Of 661 patients' data examined, clinical prediction rules were documented in 15 (2.3%). In total, 422 patients (63.8%) had required information on modified Wells criteria and D-dimer assays and were included for further analysis. PE on CTPA was present in 22 (5.21%) of PE unlikely (mWS ≤4) and 1 (0.24%) of D-dimer negative patients. Thirty patients (7.11%) met the avoidable CTPA (DD negative+PE unlikely) criteria, and it was significantly associated with dyspnea. The value of sensitivity of avoidable CTPA was 100%, whereas the positive predictive value was 90.3%. Underutilization of clinical prediction rules before prescribing CTPA is common in emergency departments. Therefore, a mandatory policy should be implemented regarding the evaluation of avoidable CTPA imaging to reduce CTPA overuse.

Pulmonary Vein Sign on Computed Tomography Pulmonary Angiography in Proximal and Distal Chronic Thromboembolic Pulmonary Hypertension With Hemodynamic Correlation.

Pulmonary vein sign (PVS) indicates abnormal pulmonary venous flow on computed tomography pulmonary angiography (CTPA) is a frequent finding in proximal chronic thromboembolic pulmonary hypertension (CTEPH). PVS's occurrence in distal CTEPH and correlation to disease severity is unknown. Using right heart catheterization data, we evaluated the relationship between PVS and CTEPH disease distribution and severity. A total of 93 consecutive CTEPH cases with both CTPA and right heart catheterization were identified in this retrospective multi-institutional study. After excluding 17 cases with suboptimal CTPA, there were 52 proximal and 24 distal CTEPH cases. Blood flow in the major pulmonary veins was graded qualitatively. Subgroup analysis of PVS was performed in 38 proximal CTEPH cases before and after pulmonary endarterectomy. PVS was more frequent in proximal (79%) than distal CTEPH (29%) ( P <0.001). No significant difference was noted in invasive mean pulmonary artery pressure (46±11 and 41±12mmHg) or pulmonary vascular resistance (9.4±4.5 and 8.4±4.8 WU) between the 2 groups. In the subgroup analysis, PVS was present in 29/38 patients (76%) before surgery. Postoperatively, 33/38 cases (87%, P <0.001) had normal venous flow (mean pulmonary artery pressure 46±11 and 25; pulmonary vascular resistance 9.2±4.3 and 2.6 WU preop and postop, respectively). PVS is a common feature in proximal but infrequent findings in distal CTEPH. PVS does not correlate with hemodynamic severity. PVS resolution was seen in the majority of patients following successful endarterectomy.

ROLE OF CT PULMONARY ANGIOGRAPHY IN EVALUATION OF PULMONARY THROMBOEMBOLISM IN COVID-19 POSITIVE PATIENTS

Introduction- COVID-19 disease has been strongly associated with a pro thrombotic state and vascular endothelial damage resulting into wide range of thromboembolic phenomena including deep venous thrombosis involving extremeties, pulmonary artery thrombo-embolism and eventually pulmonary infarctions. Computed tomography pulmonary angiography (CTPA) was used at our hospital for assessment of patients with risk of pulmonary embolism. It plays a vital role in its establishing its diagnosis, defining its extent, stage and thereby guiding towards further management. Materials and Methods- A Retrospective study was performed in Sri Aurobindo Medical College and Post graduate Institute, Indore, Madhya Pradesh, India and was approved by the ethical committee. It was performed on 250 COVID-19 patients with clinically suspected pulmonary thromboembolism who underwent CTPA between the months of December 2021 and May 2021. The scans were analysed by skilled radiologists, having good experience in the field of CT reporting. Results- Our study demonstrated that approx. 14% of the patients had pulmonary thromboembolism and these cases were observed in patients with moderate to severe lung involvement. ConclusionIn this study, we have thoroughly tried to assess the presence of pulmonary thromboembolism using CTPA and establish its relationship with severity of lung involvement on HRCT

COVID-19 related myopericarditis in a 29-year-old patient: A case report

The manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, are mainly characterized by respiratory symptoms. However, cardiac manifestations such as acute myopericarditis have been reported to be associated with COVID-19 infection. A 29-year-old female patient presented with a 2-day history of fever, cough, runny nose, and myalgia, and tested COVID-19 positive at Penang General Hospital, Pulau Pinang, Malaysia. On day 2 of admission, the patient complained of acute onset central chest pain, radiating to her back, associated with cold sweat, shortness of breath and generalised body ache. On examination, tachycardia and tachypnoea were elicited. The serial electrocardiography (ECG) showed persistent non-specific sinus tachycardia. Troponin T level was elevated at 99 ng/L (normal &amp;#60;15 ng/L) and creatine kinase (CK) was at 10990 U//L (normal: &amp;#60;190 U/L). Her chest radiograph revealed cardiomegaly and otherwise clear lung field. CT pulmonary angiogram demonstrated evidence of bilateral pleural effusion and pericardial effusion and ruled out pulmonary embolism. The diagnosis of myopericarditis was established based on clinical, electrocardiographic, radiological, and biochemical findings. She was treated successfully with IV morphine, oral colchicine, ibuprofen, and oxygen therapy. A follow-up echocardiogram 10 weeks post-COVID demonstrated complete resolution of pericardial effusion, with an election fraction of &amp;#62;70%. COVID-19 patients may develop severe cardiac complications such as myopericarditis. Clinicians should have a high index of suspicion of COVID-related myopericarditis in COVID-19 management. Further study should be implemented to investigate the association between COVID-19 and myopericarditis.

Prediction of in-hospital adverse clinical outcomes in patients with pulmonary thromboembolism, machine learning based models.

Pulmonary thromboembolism (PE) is the third leading cause of cardiovascular events. The conventional modeling methods and severity risk scores lack multiple laboratories, paraclinical and imaging data. Data science and machine learning (ML) based prediction models may help better predict outcomes. In this retrospective registry-based design, all consecutive hospitalized patients diagnosed with pulmonary thromboembolism (based on pulmonary CT angiography) from 2011 to 2019 were recruited. ML based algorithms [Gradient Boosting (GB) and Deep Learning (DL)] were applied and compared with logistic regression (LR) to predict hemodynamic instability and/or all-cause mortality. A total number of 1,017 patients were finally enrolled in the study, including 465 women and 552 men. Overall incidence of study main endpoint was 9.6%, (7.2% in men and 12.4% in women; p-value = 0.05). The overall performance of the GB model is better than the other two models (AUC: 0.94 for GB vs. 0.88 and 0.90 for DL and LR models respectively). Based on GB model, lower O2 saturation and right ventricle dilation and dysfunction were among the strongest adverse event predictors. ML-based models have notable prediction ability in PE patients. These algorithms may help physicians to detect high-risk patients earlier and take appropriate preventive measures.

CTPA ordering trends in local emergency departments: are they increasing and did they increase as a result of COVID-19?

Ordering trends for computed tomographic pulmonary angiogram (CTPA) studies by local emergency departments were assessed, along with the impact of the COVID-19 pandemic on these ordering trends and CTPA positivity rates. A retrospective quantitative analysis was performed on all CTPA studies ordered between February 2018 - January 2022 by three local tertiary care emergency rooms to investigate for pulmonary embolism. Data collected from the first two years of the COVID-19 pandemic was compared to the two years prior to the pandemic to assess for significant changes in ordering trends and positivity rates. The overall number of CTPA studies ordered increased from 534 studies in 2018-2019 to 657 in 2021-2022 and the rate of positive diagnosis of acute pulmonary embolism varied between 15.8% to 19.5% over the four years studied. There was no statistically significant difference in the number of CTPA studies ordered when comparing the first two years of the COVID-19 pandemic to the two years immediately prior; however, the positivity rate was significantly higher during the first two years of the pandemic. Over the studied period from 2018-2022, the overall number of CTPA studies ordered by local emergency departments has increased, in line with literature reports from other locations. There was also a correlation between the onset of the COVID-19 pandemic and CTPA positivity rates, possibly secondary to the prothrombotic nature of this infection or the increase in sedentary lifestyles during lockdown periods.

Right ventricular area predicts short-term mortality in acute pulmonary embolism based on CT pulmonary angiography: A retrospective study.

We performed this cohort study to assess the prognostic value of right ventricular size, including diameter, area, and volume, in short-term mortality of acute pulmonary embolism (APE) based on 256-slice computed tomography compared with D-dimer, creatine kinase muscle and brain isoenzyme, and Wells scores. A total of 225 patients with APE, who were followed up for 30 days were enrolled in this cohort study. Clinical data, laboratory indices (creatine kinase, creatine kinase muscle and brain isoenzyme, and D-dimer), and Wells scores were collected. The 256-slice computed tomography was used to quantify cardiac parameters (RVV/LVV, RVD/LVD-ax, RVA/LVA-ax, RVD/LVD-4ch, RVA/LVA-4ch) and the diameter of the coronary sinus. Participants were divided into non-death and death groups. The values mentioned above were compared between the 2 groups. The RVD/LVD-ax, RVA/LVA-ax, RVA/LVA-4ch, RVV/LVV, D-dimer, and creatine kinase levels were significantly higher in the death group than in the non-death group (P < .05). The active period of the malignant tumor, heart rate ≥ 100 beats/minutes, and RVA/LVA-ax were positively correlated with early death from APE (P < .05). Active stage of malignant tumor (OR:9.247, 95%CI:2.682-31.888, P < .001) and RVA/LVA-ax (OR:3.073, 95%CI:1.447-6.528, P = .003) were independent predictors of early death due to APE. According to the receiver operating characteristic curve, the cutoff point of RVA/LVA-ax was 1.68 with a sensitivity of 46.7% and specificity of 84.8%. The measurement of ventricular size in the short-axis plane is more convenient and reliable than that in the 4-chamber cardiac plane. RVA/LVA-ax is an independent predictor of early death from APE, and when RVA/LVA-ax > 1.68, the risk of early death from APE increases.

Individualized Scan Protocol Based on Body Mass Index in Dual-Energy Computed Tomography Pulmonary Angiography to Reduce Radiation and Contrast Doses with Improved Image Quality.

BACKGROUND We evaluated an individualized dual-energy computed tomography (DECT) scan protocol by combining optimal monochromatic images with an appropriate ASIR-V reconstruction strength in computed tomography pulmonary angiography (CTPA) to reduce radiation and iodine doses and superior vena cava (SVC) artifacts. MATERIAL AND METHODS A total of 127 patients who underwent CTPA were prospectively enrolled and randomly divided into a standard (n=63) and individualized group (n=64). The standard group used 120 kVp, 150 mAs, and 60 mL contrast media at an injection rate of 5 mL/s; the individualized group used DECT imaging mode with tube current selected according to patients' BMI (BMI ≤20 kg/m², 200 mA; 20< BMI ≤23 kg/m², 240 mA; 23< BMI ≤25 kg/m², 280 mA; BMI >25 kg/m², 320 mA). Contrast media intake was 130 mgI/kg with an injection time of 7 s. The data in the individualized group was reconstructed to 55-70 keV (5 keV interval) monochromatic images combined with 40-80% ASIR-V (10% interval). Radiation dose, contrast dose, and image quality were compared between the groups. RESULTS There were no significant differences in patient habitus. Compared with the standard group, the individualized group significantly decreased radiation dose by 33.93% (3.31±0.57 mSv vs 5.01±0.34 mSv) and contrast dose by 56.95% (9.04±1.40 gI vs 21.00±0.00 gI). The 60 keV image with 80%ASIR-V in the individualized group provided the best image quality and further reduced SVC beam-hardening artifacts. CONCLUSIONS The use of BMI-dependent DECT protocol in CTPA further reduces radiation dose, contrast agent dose, and SVC artifacts, with the 60 keV images reconstructed using 80%ASiR-V having the best image quality.

Evaluating the Performance of a Commercially Available Artificial Intelligence Algorithm for Automated Detection of Pulmonary Embolism on Contrast-Enhanced Computed Tomography and Computed Tomography Pulmonary Angiography in Patients With Coronavirus Disease 2019

ObjectiveTo investigate the performance of a commercially available artificial intelligence (AI) algorithm for the detection of pulmonary embolism (PE) on contrast-enhanced computed tomography (CT) scans in patients hospitalized for coronavirus disease 2019 (COVID-19). Patients and MethodsRetrospective analysis was performed of all contrast-enhanced chest CT scans of patients admitted for COVID-19 between March 1, 2020 and December 31, 2021. Based on the original radiology reports, all PE-positive examinations were included (n=527). Using a reversed-flow single-gate diagnostic accuracy case-control model, a randomly selected cohort of PE-negative examinations (n=977) was included. Pulmonary parenchymal disease severity was assessed for all the included studies using a semiquantitative system, the total severity score. All included CT scans were sent for interpretation by the commercially available AI algorithm, Aidoc. Discrepancies between AI and original radiology reports were resolved by 3 blinded radiologists, who rendered a final determination of indeterminate, positive, or negative. ResultsA total of 78 studies were found to be discrepant, of which 13 (16.6%) were deemed indeterminate by readers and were excluded. The sensitivity and specificity of AI were 93.2% (95% CI, 90.6%-95.2%) and 99.6% (95% CI, 98.9%-99.9%), respectively. The accuracy of AI for all total severity score groups (mild, moderate, and severe) was high (98.4%, 96.7%, and 97.2%, respectively). Artificial intelligence was more accurate in PE detection on CT pulmonary angiography scans than on contrast-enhanced CT scans (P<.001), with an optimal Hounsfield unit of 362 (P=.048). ConclusionThe AI algorithm demonstrated high sensitivity, specificity, and accuracy for PE on contrast-enhanced CT scans in patients with COVID-19 regardless of parenchymal disease. Accuracy was significantly affected by the mean attenuation of the pulmonary vasculature. How this affects the legitimacy of the binary outcomes reported by AI is not yet known.

Pulmonary Embolism with Negative D-Dimer

Venous thromboembolism is condition characterized by the presence of blood clot that resides in the venous system. It encompasses deep vein thrombosis which is represented by development of de novo blood clot in the deep venous system of the limbs (commonly lower limbs) and pulmonary embolism, which emerges as the preformed blood clots mobilize and occlude the pulmonary circulation. Here, we present a case of a 44 year old lady who was diagnosed with pulmonary embolism proven by CT pulmonary angiogram despite having a negative d-dimer assay.

Assessment of Utility of Computed Tomography Pulmonary Angiography in Pulmonary Embolism

Background: Among all the available diagnostic tools, computed tomography (CT) is the preferred diagnostic tool for clinically suspected pulmonary embolism (PE) cases. Further, with the development of multi–detector row CT (MDCT) technology, previous limitations of CT have been overcome effectively. For patients with clinical suspicion of PE, MDCT pulmonary angiography has become the first line of modality for the diagnosis. Aims and Objectives: To evaluate various common observations of CT pulmonary angiography (CTPA) in suspected cases of PE that could accurately determine the choice of management. Materials and Methods: Fifty patients with clinically suspected PE referred to the department of Radiodiagnosis for CTPA from various departments were studied in the cross-sectional study. CT images were obtained with a SIEMENS 64-slice multi-detector CT scanner (somatom definition AS). Images were reconstructed into 3D, axial, coronal, sagittal maximum intensity projection sections, and volume rendering techniques. The axial as well as reformatted coronal and sagittal images were evaluated. Results: The incidence of PE was 52%. The incidence of PE was highest in patients older than 60 years (30.8%) and males (30.3%; p=0.662). The most common symptoms evoking a suspicion of pulmonary embolism were dyspnea (69.2%), followed by chest pain (15.4%), cough (11.5%), and hemoptysis (3.8%). Out of 26 patients who had PE, 61.5% had right ventricular enlargement. DVT (23.1%) was the most common past history. The majority of the patients had thrombus in the right main pulmonary artery (21.1 %), followed by the left main pulmonary artery (19.3 %). Conclusion: In clinically suspected cases of PE, MDCT pulmonary angiography was a useful diagnostic tool. CTPA is the modality of choice for its rapid, minimally invasive, and well-tolerated nature.

Comparative Overview of Different Radiological Imaging Techniques in the Diagnosis of Pulmonary Embolism

Background: Imaging techniques such as chest X-ray (CXR), computed tomography pulmonary angiography (CTPA), ventilation-perfusion (V/Q) scintigraphy, and magnetic resonance imaging (MRI) are some methods used to detect and manage acute pulmonary embolism (PE). The aim of this review was a comparative analysis of the various imaging techniques used to evaluate PE. Methods and Results: The incidence, distribution, clinical features, classification of PE and clinical assessment of the current methods for diagnosis of PE were discussed. CTPA is the gold standard for fast turnaround and accurate diagnosis. Additional probable reasons for sudden chest pain can also be learned through a CT scan. Lung perfusion anomalies can be identified and measured using dual-energy CT. Chest radiographs are only marginally beneficial, occasionally revealing PE or infarction signs, but are helpful in ruling out other possible causes of chest pain. These patients' ventilation-perfusion mismatches are evident in the V/Q scan, which has many grading schemes with conventional ranges from normal to high. While MRI, which is only available in specialist facilities and calls for higher degrees of competence, also offers accurate diagnosis. Conclusion: Early diagnosis and treatment of PE is challenging due to asymptomatic conditions or overlapping symptoms. Diagnosis of PE in expectant mothers and those with suspected PE recurrence is typically difficult. Over-diagnosis and overtreatment, particularly regarding sub-segmental PE, and the lowered clinical suspicion threshold remain a major concern in PE diagnosis. The routine use and integration of the above diagnostic techniques need to be encouraged in clinical practice to overcome the diagnostic hurdles. The introduction of new diagnostic techniques or improved risk stratification processes might enhance the management of PE.

Patient and Fetal Radiation-Induced Malignancy Risk From Imaging For Evaluation of Pulmonary Embolism in Pregnancy

BackgroundImaging for diagnosis of suspected pulmonary embolism in pregnancy presents radiation concerns for patient and fetus. ObjectivesEstimate the risks of radiation-induced breast cancer and childhood leukemia from common imaging techniques for the evaluation of suspected pulmonary embolism in pregnancy. MethodsBreast and uterine absorbed doses for various imaging techniques were input into the National Cancer Institute Radiation Risk Assessment Tool to calculate risk of breast cancer for the patient and childhood leukemia for the fetus. Absorbed doses were obtained by synthesizing data from a recent systematic review and the International Commission on Radiological Protection. Primary outcomes were the estimated excess incidences of breast cancer and childhood leukemia per 100,000 exposures. ResultsBaseline incidences of breast cancer for a 30-year-old woman and childhood leukemia for a male fetus were 13,341 and 939, respectively. Excess incidences of breast cancer were 0.003 and 0.275 for a single and two-view chest radiograph, respectively, 9.53 and 20.6 for low- and full-dose computed tomography pulmonary angiography (CTPA), respectively, 0.616 and 2.54 for low- and full-dose perfusion scan, respectively, and 0.732 and 2.66 for low- and full-dose ventilation perfusion scan, respectively. Excess incidences of childhood leukemia were 0.004 and 0.007 for a single and two-view chest radiograph, respectively, 0.069 and 0.490 for low- and full-dose CTPA, respectively, 0.359 and 1.47 for low- and full-dose perfusion scan, respectively, and 0.856 and 1.97 for low- and full-dose ventilation perfusion scan, respectively. ConclusionExcess cancer risks for all techniques were small relative to baseline cancer risks, with CTPA techniques carrying slightly higher risk of breast cancer for the patient and ventilation perfusion techniques a higher risk of childhood leukemia.

Clinical characteristics of venous thromboembolism onset from severe high altitude pulmonary edema in plateau regions

BackgroundTo investigate venous thromboembolism (VTE) in hospitalized patients with severe high altitude pulmonary edema (HAPE), we performed a single center retrospective study to evaluate its clinical characteristics, prognosis, and potential thromboprophylaxis strategies in a large referral and treatment center in plateau regions.MethodsWe studied a total of 18 patients with severe HAPE from January 1, 2012 to December 31, 2021. Demographic and clinical data, laboratory data, including ultrasound scans of the lower extremities and cardiac ultrasound, and computed tomographic pulmonary angiography (CTPA) variables were obtained, and comparisons were made between groups with and without VTE.ResultsOf the 18 patients hospitalized with severe HAPE (age 43 (range, 34–54) years, 14 [77.8%] men), 7 patients developed VTE (38.9%), including 5 with deep vein thrombosis (DVT) and pulmonary embolism (PE), 2 of whom had DVT only. Eighteen patients are all firstly rapid ascent to high altitudes which the mean altitude was 3700 m (3656–4050 m). Compared with patients who did not have VTE, patients with VTE had a longer time in hospital (13 [11, 19] versus 9 [7, 12]; P = 0.027), respiratory failure (6 [85.7%] versus 2 [18.2%]; P = 0.013), the shortened APTT (21.50 [19.00, 27.50] versus 26.30 [24.80, 30.10]; P = 0.044) and the higher level of D-dimer (7.81 [4.62, 9.60] versus 2.90 [1.75, 3.37]; P = 0.003). The proportion of thromboprophylaxis is too low in our cohort which 2 of 18 (11.1%) patients were given VTE prophylaxis. There was no statistically significant difference between the VTE and non-VTE groups (0 [0.0%] versus 2 [18.2%]; P = 0.497).ConclusionsThe prevalence of VTE is high in hospitalized patients with severe high altitude pulmonary edema (HAPE). Prophylaxis for venous thromboembolism may be protective in severe HAPE patients after admission. Our data seem to suggest that VTE is probably an additional prognostic factors in patients with severe HAPE.

Comparison of CT Values between Thrombus and Postmortem Clot Based on Cadaveric Pulmonary Angiography.

To explore the difference in CT values between pulmonary thromboembolism and postmortem clot in postmortem CT pulmonary angiography (CTPA) to further improve the application value of virtual autopsy. Postmortem CTPA data with the definite cause of death from 2016 to 2019 were collected and divided into pulmonary thromboembolism group (n=4), postmortem clot group (n=5), and control group (n=5). CT values of pulmonary trunk and left and right pulmonary artery contents in each group were measured and analyzed statistically. The average CT value in the pulmonary thromboembolism group and postmortem clot group were (168.4±53.8) Hu and (282.7±78.0) Hu, respectively, which were lower than those of the control group (1 193.0±82.9) Hu (P<0.05). The average CT value of the postmortem clot group was higher than that of the pulmonary thromboembolism group (P<0.05). CT value is reliable and feasible as a relatively objective quantitative index to distinguish pulmonary thromboembolism and postmortem clot in postmortem CTPA. At the same time, it can provide a scientific basis to a certain extent for ruling out pulmonary thromboembolism deaths.