Clinical and imaging profiles of pulmonary embolism: a single-institution experience

Novel intravascular tantalum oxide-based contrast agent achieves improved vascular contrast enhancement and conspicuity compared to Iopamidol in an animal multiphase CT protocol

BACKGROUND

To assess thoracic vascular computed tomography (CT) contrast enhancement of a novel intravenous tantalum oxide nanoparticle contrast agent (carboxybetaine zwitterionic tantalum oxide, TaCZ) compared to a conventional iodinated contrast agent (Iopamidol) in a rabbit multiphase protocol.

METHODS

Five rabbits were scanned inside a human-torso-sized encasement on a clinical CT system at various scan delays after intravenous injection of 540 mg element (Ta or I) per kg of bodyweight of TaCZ or Iopamidol. Net contrast enhancement of various arteries and veins, as well as image noise, were measured. Randomized scan series were reviewed by three independent readers on a clinical workstation and assessed for vascular conspicuity and image artifacts on 5-point Likert scales.

RESULTS

Overall, net vascular contrast enhancement achieved with TaCZ was superior to Iopamidol (p ≤ 0.036 with the exception of the inferior vena cava at 6 s (p = 0.131). Vascular contrast enhancement achieved with TaCZ at delays of 6 s, 40 s, and 75 s was superior to optimum achieved Iopamidol contrast enhancement at 6 s (p ≤ 0.036. Vascular conspicuity was higher for TaCZ in 269 of 300 (89.7%) arterial and 269 of 300 (89.7%) venous vessel assessments, respectively (p ≤ 0.005), with substantial inter-reader reliability (κ = 0.61; p < 0.001) and strong positive monotonic correlation between conspicuity scores and contrast enhancement measurements (ρ = 0.828; p < 0.001).

CONCLUSION

TaCZ provides absolute and relative contrast advantages compared to Iopamidol for improved visualization of thoracic arteries and veins in a multiphase CT protocol.

RELEVANCE STATEMENT

The tantalum-oxide nanoparticle is an experimental intravenous CT contrast agent with superior cardiovascular and venous contrast capacity per injected elemental mass in an animal model, providing improved maximum contrast enhancement and prolonged contrast conspicuity. Further translational research on promising high-Z and nanoparticle contrast agents is warranted.

KEY POINTS

There have been no major advancements in intravenous CT contrast agents over decades. Iodinated CT contrast agents require optimal timing for angiography and phlebography. Tantalum-oxide demonstrated increased CT attenuation per elemental mass compared to Iopamidol. Nanoparticle contrast agent design facilitates prolonged vascular conspicuity.

Exploring varied radiologic appearance in pulmonary embolism with CT pulmonary angiography: Case series with literature review

Pulmonary embolism (PE) is a life-threatening condition caused by a sudden blockage of pulmonary arteries. Nonspecific and extremely variable clinical presentation frequently leads to undetected cases, making computed tomography pulmonary angiography (CTPA) hold a crucial role in the diagnosis of PE. This case series presents numerous types and findings of PE in CTPA among patients with different initial presentations followed by a literature review. We presented 3 cases with different initial presentations such as dyspnea with wheezing, productive cough, and hematemesis. All patients were consequently evaluated for D-dimer due to suspicion of PE from cardiac ultrasonography, electrocardiography (ECG), and persistent symptoms. Large to subsegmental PE can be found with various secondary findings such as pleural effusion and Hampton's hump. All patient's conditions were improved after anticoagulant treatment. This case series highlights the significance of CTPA as an imaging modality in the diagnosis of PE, as well as the necessity of evaluating the main to subsegmental pulmonary artery through an in-depth understanding of the images that can be assessed on CTPA.

Beyond pulmonary embolism: Alternative diagnosis and incidental findings on CT pulmonary angiography in sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a genetic hematological disorder associated with severe complications, such as vaso-occlusive crises, acute chest syndrome (ACS), and an increased risk of thromboembolic events, including pulmonary embolism (PE). The diagnosis of PE in SCD patients presents challenges due to the overlapping symptoms with other pulmonary conditions. Our previous study revealed that nearly 96% of computed tomography pulmonary angiography (CTPA) scans in SCD patients were negative for PE, highlighting a gap in understanding the significance of CTPA findings when PE is absent.

METHODS

In this retrospective follow-up study conducted at the Salmaniya Medical Complex in Bahrain, we examined SCD patients with HbSS genotypes who underwent CTPA from January 1, 2018, to December 31, 2021, for suspected PE, but the results were negative. The aim of this study was to identify alternative diagnoses and incidental findings from CTPA scans. Experienced radiologists reviewed the CTPA images and reports to assess potential alternative diagnoses and incidental findings, incorporating an additional analysis of chest X-rays to evaluate the diagnostic value of CTPA. Incidental findings were classified based on their location and clinical significance.

RESULTS

Among the 230 evaluated SCD patients (average age 39.7 years; 53% male) who were CTPA negative for PE, 142 (61.7%) had identifiable alternative diagnoses, primarily pneumonia (49.1%). Notably, 88.0% of these alternative diagnoses had been previously suggested by chest radiographs. Furthermore, incidental findings were noted in 164 (71.3%) patients, with 11.0% deemed clinically significant, necessitating immediate action, and 87.8% considered potentially significant, requiring further assessment. Notable incidental findings included thoracic abnormalities such as cardiomegaly (12.2%) and an enlarged pulmonary artery (11.3%), as well as upper abdominal pathologies such as hepatomegaly (19.6%), splenomegaly (20.9%), and gallstones (10.4%).

CONCLUSION

This study underscores the limited additional diagnostic yield of CTPA for identifying alternative diagnoses to PE in SCD patients, with the majority of diagnoses, such as pneumonia, already suggested by chest radiographs. The frequent incidental findings, most of which necessitate further evaluation, highlight the need for a cautious and tailored approach to using CTPA in the SCD population.

Successfully conservative management of the uterus in acute pulmonary embolism during cesarean section for placenta previa: a case report from Tu Du Hospital, Vietnam and literature review

BACKGROUND

Cardiopulmonary collapse is a catastrophic event in cesarean section, which leads to adverse outcomes for both the mother and the fetus. Pulmonary embolism is one of the rare etiologies of this entity. We herein reported the successful management of acute embolism pulmonary associated with cesarean delivery on a healthy pregnant woman at our tertiary referral hospital.

CASE PRESENTATION

A full-term pregnant woman hospitalized for planned cesarean delivery due to placenta previa without cardiorespiratory diseases. She was scheduled uneventfully for a planned cesarean section. After placental delivery, the patient spontaneously fell into cardiopulmonary collapse and her vital signs deteriorated rapidly. The obstetricians promptly completed the cesarean section and performed all procedures to prevent the PPH and preserve the uterus. At the same time, the anesthesiologists continued to carry out advanced heart-lung resuscitation in order to control her vital signs. After surgery, the multidisciplinary team assessed the patient and found a thrombus in her pulmonary circulation. Therefore, the patient was managed with therapeutic anticoagulation. The patient recovered in good clinical condition and was discharged after 2 weeks without any complications.

CONCLUSIONS

The diagnosis of acute pulmonary embolism is extremely difficult due to uncommon occurrence, sudden onset, and non-specific presentation. Awareness of this life-threatening pathology during cesarean delivery should be raised. Interdisciplinary assessment must be essentially established in this life-threatening condition. After the whole conventional management, uterine conservation may be acceptable where applicable. Further data is required to encourage this finding.

Acute Pulmonary Embolism in Oman: A Situational Analysis

OBJECTIVES

Pulmonary embolism (PE) is increasingly prevalent in Oman. The aim of this situational analysis of PE among Omani patients was to study its predisposing factors, diagnostic issues, and optimal management.

METHODS

In this retrospective cross-sectional situational analysis, the subjects were Omani patients who were diagnosed with acute PE using computed tomography pulmonary angiogram from 2010-2021. The required data was collected from the hospital database and statistically analyzed.

RESULTS

The subjects were 438 patients diagnosed with PE, with a mean age of 53.3±18.5 years and mean body mass index of 29.7±7.3 kg/m2. Males were in a slight majority (223; 50.9%) and were older (55.0±18.5 years) than females (51.5±18.3 years). Two-thirds of the PE patients had hypertension and one-third had diabetes mellitus. Most patients presented with dyspnea and chest pain. Syncope was more common in females compared to males who mostly presented with hemoptysis. Nearly half of the patients had abnormal echocardiogram, and males had lower mean ejection fraction compared to females. Different modalities of management were used to treat patients' PE. Heparin was the most used anticoagulant followed by warfarin and direct oral anticoagulants. Out of the 122 PE patients who died during the study period, PE was the direct cause of death of 68 patients. The mortality was higher in males than in females.

CONCLUSIONS

The incidence of acute PE was similar among both male and female Omani patients. However, there were sex differences in risk factors, symptoms, investigations, and management of PE. Females presented with more severe PE, but mortality was higher in males.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Clinical, Radiological, and Outcome Characteristics of Acute Pulmonary Embolism: A 5-year Experience from an Academic Tertiary Center

BACKGROUND

Acute pulmonary embolism (PE) is a common and potentially life-threatening condition. This comprehensive study from a Gulf Cooperation Council (GCC) country aimed to evaluate the clinical, radiological, and outcome characteristics associated with acute PE.

METHODS

This retrospective observational study analyzed data of patients with confirmed acute PE who were admitted to the largest academic tertiary center in the State of Qatar from January 1, 2014, to December 31, 2018. Data on the clinical presentation, radiologic, and echocardiographic findings, as well as outcomes were collected.

RESULTS

A total of 436 patients were diagnosed with acute PE during the study period (male, 53%). Approximately 56% of the patients were < 50 years old at presentation, with a median age of 47 years. In approximately 69% of cases, the PE occurred outside the hospital. The main associated comorbidities were obesity (34.6%), hypertension (29.4%), and diabetes (25%). Immobilization (25.9%) and recent surgery (20.6%) were the most common risk factors. The most frequent presenting symptom was dyspnea (39.5%), and the most frequent signs were tachycardia (49.8%) and tachypnea (45%). Cardiac arrest was the initial presentation in 2.2% of cases. Chest X-ray findings were normal in 41%. On computed tomography pulmonary angiography (CTPA), 41.3% of the patients had segmental PE, 37.1% had central PE, and 64.1% had bilateral PE. The main electrocardiographic (ECG) abnormality was sinus tachycardia (98%). In patients who underwent echocardiography, right ventricular (RV) enlargement was the main echocardiographic finding (36.4%). Low-, intermediate-, and high-risk PE constituted 49.8%, 31.4%, and 18.8% of the cases, respectively. Thrombolysis was prescribed in 8.3% of the total and 24.4% of the high-risk PE cases. Complications of PE and its treatment (from admission up to 6 months post-discharge) included minor bleeding (14%), major bleeding (5%), PE recurrence (4.8%), and chronic thromboembolic pulmonary hypertension (CTEPH) (5%). A total of 15 (3.4%) patients died from PE.

CONCLUSIONS

Acute PE can manifest with complex and variable clinical and radiological syndromes. Striking findings in this study are the younger age of acute PE occurrence and the low PE-related mortality rate.

Pulmonary Embolism and Chronic Superior Vena Cava Occlusion Complicating Central Line-Associated Venous Thromboembolism in a Sickle Cell Disease Patient

Sickle cell disease (SCD), the most common genetic disorder globally, is often associated with an increased risk of venous thromboembolic events (VTE). Many of these patients have central lines placed for the purposes of repeated medication administration, blood transfusions, and blood draw, further increasing the risk of VTE. Given the non-specific presentation of VTE and pulmonary embolism, as well as the risk of mortality if interventions are delayed, a high index of suspicion is required for early diagnosis of the condition. We report the case of a 35-year-old woman with SCD and a port-a-cath in place who presented with extensive upper extremity and intrathoracic VTE with associated pulmonary embolism and chronic superior vena cava (SVC) occlusion. We also discuss the peculiarities of the clinical manifestations and management of VTE and pulmonary embolism in the setting of SCD based on the evidence from existing literature.