Diagnosis of pulmonary infarction in post-mortem computed tomography and post-mortem magnetic resonance imaging-a technical note.

Pulmonary thromboembolism may be accompanied by pulmonary infarction. Even though pulmonary thromboembolism (PTE) is a frequently found cause of death at autopsy, pulmonary infarction accompanying PTE is a less common finding and may therefore easily be misinterpreted as infectious or cancerous lung disease. Appearance of pulmonary infarction in post-mortem imaging and acquisition parameters helping to identify pulmonary infarctions are not described yet. Based on a case of a 50-year-old man who died due to PTE and presented pulmonary infarction, we suggest using a pulmonary algorithm in post-mortem computed tomography combined with post-mortem magnetic resonance imaging of the lungs using conventional T1- and T2-weighted sequences.

Morphological characteristics of the reversed halo sign that may strongly suggest pulmonary infarction.

AIM: To analyse the morphological characteristics of the reversed halo sign (RHS) on unenhanced chest computed tomography (CT), which raise suspicion of pulmonary infarction (PI) associated with pulmonary embolism (PE), and to compare these characteristics with those observed in the RHS caused by other diseases. MATERIAL AND METHODS: CT images of 145 patients (250 RHSs) were reviewed retrospectively. Sixty-four patients had the RHS due to PI; in 81 immunocompetent patients, the RHS was caused by alternative pulmonary diseases. All PIs secondary to PE were confirmed at CT angiography. Other diagnoses were confirmed using published criteria. Two independent thoracic radiologists, who were blinded patient demographics, clinical data, and final diagnoses, analysed the morphological CT features of the RHSs. RESULTS: Seventy-four RHSs were found in the PI group and 176 RHSs in the group of other diseases. Single RHSs were associated more frequently with PI compared with the group without PIs; three or more lesions were seen only in patients with other diseases. Low-attenuation areas inside the RHS, with or without reticulation, were observed in 94.59% of PI-associated lesions, and in no patient in the group without PI (p<0.001). Subpleural involvement (p<0.001) and lower-lung predominance (p=0.001) were also associated more frequently with PI. Pleural effusion was observed in 64.06% of patients with PI and in only 6.17% of those with other diseases (p<0.001). CONCLUSIONS: A single RHS with low-attenuation areas inside the halo, with or without reticulation, is highly suggestive of PI. Lower-lung predominance and pleural effusion also suggest PI.

Lung infarction secondary to infected pulmonary arterial thrombosis in a patient with Eisenmenger's syndrome.

A case is presented where a patient with Eisenmenger's syndrome is successfully treated for infection of chronic pulmonary arterial thrombosis with good effect. The evidence for antibiotic and anticoagulant therapy in this patient group is discussed.

Laser-targeted photosensitizer-induced lung injury: noninvasive rat model of pulmonary infarction.

Pulmonary infarction is a life-threatening lung injury that requires rapid and accurate diagnosis for proper treatment. Targetable and reproducible small-animal models that would allow experimental development and preclinical evaluation of diagnostic methods for detecting pulmonary infarction are critically missing. The authors report here a novel procedure to selectively induce pulmonary infarction by photodestructive laser-light irradiation in a targeted location within a specific lung compartment after administration of a photosensitizer. Histopathological analysis of the illuminated lung tissue revealed massive hemorrhage and vascular occlusion after acute injury localized to the site of irradiation. Collapse of alveolar structure, neutrophil influx, and necrosis were subsequently observed. Computed tomography (CT) scans showed evidence of abnormal density and airspace consolidation in the irradiated area of the lung, but not elsewhere in the lung compartment. Perfusion imaging using 99mTc-labeled macroaggregated albumin by single-photon emission computed tomography revealed diminished scintigraphic signal in the opaque area of infarcted lung tissue. The histological changes, CT findings, and perfusion characteristics of pulmonary infarction are mimicked using laser-irradiated, photosensitizer-mediated photodestruction to selectively induce chronic lung injury in a localized area. This small-animal model can be easily and readily used for targeted induction of pulmonary infarction in a designated area of lung compartment and offers the potential for use in evaluating novel diagnostic and therapeutic methods.

CT evaluation of chronic thromboembolic pulmonary hypertension.

The educational objectives of this article are to provide an overview of the computed tomography (CT) findings in chronic thromboembolic pulmonary hypertension. This article reviews the key imaging findings at CT in patients with chronic thromboembolic pulmonary hypertension. After reading this article, the reader should have an improved awareness of the condition, its imaging features, and the CT imaging features associated with surgically accessible disease.

Pulmonary cavitation in a patient presenting with nonspecific complaints.

Most commonly, patients with pulmonary embolism present with dyspnea, chest pain, and/or tachypnea to the emergency department (ED). The presence of multiple suggestive symptoms, especially when severe, significantly reduces delay in diagnosis. We report a case of an 86-year-old patient presenting to the ED with nonspecific complaints: she claimed to feel lethargic and "reluctant to prepare meals." She did not complain of either dyspnea or chest pain. As underlying cause, an intrapulmonary cavitation with pulmonary embolism was found. The combination of absence of specific symptoms regarding pulmonary embolism and radiologic findings of an obstructed pulmonary artery supplying the cavitary lung segment is rare. Common etiologies of cavitary lung processes are discussed, and risk factors of pulmonary infarction are highlighted.

A retrospective study of pulmonary infarction in patients with systemic lupus erythematosus from southern Taiwan.

Since large-scale reports of pulmonary infarction in systemic lupus erythematosus (SLE) are limited, a retrospective study was performed for this manifestation in 773 hospitalized patients in southern Taiwan from 1999 to 2009. Pulmonary infarction was defined as the presence of pulmonary embolism, persistent pulmonary infiltrates, and characteristic clinical symptoms. Demographic, clinical, laboratory, and radiological images data were analyzed. There were 12 patients with pulmonary embolism and 9 of them had antiphospholipid syndrome (APS). Six patients (19 to 53 years, average 38.2 ± 12.6) with 9 episodes of lung infarction were identified. All cases were APS and four episodes had coincidental venous thromboembolism. There were four episodes of bilateral infarction and seven episodes of larger central pulmonary artery embolism. Heparin therapy was routinely prescribed and thrombolytic agents were added in two episodes. Successful recovery was noted in all patients. In conclusion, there was a 0.8% incidence of pulmonary infarction in patients with SLE, all with the risk factor of APS. Differentiation between pulmonary infarction and pneumonia in lupus patients should be made; they have similar chest radiography with lung consolidation but require a different clinical approach in management. Although this report is a retrospective study with relatively small numbers of lupus patients with lung infarcts, our observation might provide beneficial information on the clinical features and radiological presentations during the disease evolution of pulmonary infarction in SLE with APS.

Long-term clinical outcome of patients with persistent right ventricle dysfunction or pulmonary hypertension after acute pulmonary embolism.

AIMS: Persistent, echocardiography-assessed right ventricle dysfunction (RVD) and/or pulmonary hypertension (PHT) are relatively frequent findings after an acute pulmonary embolism (PE). It has been suggested that echocardiography might predict long-term adverse events. Our objectives were to evaluate the prognostic value of RVD or isolated PHT 6 months after an acute PE with regard to all-cause mortality or venous thromboembolism (VTE) recurrence. METHODS AND RESULTS: In a previous study, echocardiography was used to assess RVD or PHT on admission and 6 months after an acute PE in 101 consecutive, haemodynamically stable pulmonary patients. We assessed the subsequent vital status and incidence of recurrent VTE in these patients. Six patients were lost for follow-up. The other 95 patients were categorized as those (i) with RVD or PHT 6 months after PE (17 cases, 17.8%) and (ii) patients with neither RVD nor PHT (78 cases, 82.1%). After a mean±SD of 2.8±1.06 years, there were 9 (9.4%) deaths and 12 (12.6%) VTE recurrences. At multivariate analysis, only age predicted all-cause mortality [hazard ratio (HR): 1.081, 95% confidence interval (CI): 1.003-1.166, P=0.004]. RVD or PHT persistence did not appear to increase the risk of mortality or recurrent VTE. CONCLUSION: Persistent echocardiographic signs of right ventricular pressure overload 6 months after an acute PE did not predict long-term adverse outcome events in this study.

Non-surgical management of an abrupt cavitation and large oval-shaped lung abscess secondary to acute thromboembolic pulmonary infarction: a case report.

Infected cavitating pulmonary infarction is a rare complication of pulmonary embolism with a high mortality rate. Surgical excision for this complication has been used in past decades. Abrupt cavitation and a large oval-shaped lung abscess caused by acute thromboembolic pulmonary infarction during anticoagulation are rare. We present a 70-year-old man who suffered from pleuritic pain and breathlessness, accompanied by nausea and vomiting for 1 day. A physical examination showed tachycardia and tachypnea with moist rales in the left upper chest. High D-dimer levels, leukocytosis, respiratory failure and left upper lobe consolidation were found on plain computed tomography (CT). CT pulmonary angiography was performed 2 days after the previous CT scan because pulmonary embolism was suspected. This scan showed emboli in the main, right upper, middle, lower and left upper pulmonary arteries with deteriorated left upper lobe consolidation and cavitation. Thromboembolic pulmonary infarction and an abscess were diagnosed. Enoxaparin 60 mg was administered every 12 hours for 10 days, followed by rivaroxaban, antibiotics and drainage of the hydrothorax. The patient improved after the strategy of non-surgical treatment and was discharged approximately 1 month later. The patient had an uneventful course during rivaroxaban 20 mg once daily for 1 year.

The "Survived Lung:" An Ultrasound Sign of "Bubbly Consolidation" Pulmonary Infarction.

Since the presence of "bubbly consolidation" (central lucencies) on a multi-slice computed tomography pulmonary angiography (MCTPA) is one of the highly specific imaging appearances of infarct secondary to pulmonary embolism, we investigated the ultrasound characteristics of these infarctions. In this study, 118 patients with MCTPA diagnosis of acute pulmonary embolism were enrolled. Pulmonary infarctions were detected in 21 patients (17.7%), of which 10 (47.6%) showed the typical appearance of bubbly consolidation on MCTPA. Lung ultrasound (LUS) was performed to evaluate the characteristics of the infarcts highlighted by MCTPA. The bubbly consolidations showed a very peculiar echographic aspect represented by a triangular hypoechoic consolidation with sharp margins, the absence of air bronchograms and a mostly central roundish hyperechoic area. Air lucencies within a pulmonary infarct is hypothesized to represent the coexistence of aerated non-infarcted lung with the infarcted lung in the same lobule. The ultrasound appearance confirms this hypothesis, so we named the roundish hyperechoic area the "survived lung." This picture was found in all patients with a diagnosis of bubbly consolidation on MCTPA (100%). Χ2 between MCTPA and LUS regarding the bubbly consolidation diagnosis is 17.18 (df = 1; p value = 0.00003). Bubbly consolidations show a very typical appearance on LUS. Their detection suggests further investigations (MCTPA or point-of-care multi-organ ultrasonography).

Patterns of organizing pneumonia and microinfarcts as surrogate for endothelial disruption and microangiopathic thromboembolic events in patients with coronavirus disease 2019.

BACKGROUND: To evaluate chest-computed-tomography (CT) scans in coronavirus-disease-2019 (COVID-19) patients for signs of organizing pneumonia (OP) and microinfarction as surrogate for microscopic thromboembolic events. METHODS: Real-time polymerase-chain-reaction (RT-PCR)-confirmed COVID-19 patients undergoing chest-CT (non-enhanced, enhanced, pulmonary-angiography [CT-PA]) from March-April 2020 were retrospectively included (COVID-19-cohort). As control-groups served 175 patients from 2020 (cohort-2020) and 157 patients from 2019 (cohort-2019) undergoing CT-PA for pulmonary embolism (PE) during the respective time frame at our institution. Two independent readers assessed for presence and location of PE in all three cohorts. In COVID-19 patients additionally parenchymal changes typical of COVID-19 pneumonia, infarct pneumonia and OP were assessed. Inter-reader agreement and prevalence of PE in different cohorts were calculated. RESULTS: From 68 COVID-19 patients (42 female [61.8%], median age 59 years [range 32-89]) undergoing chest-CT 38 obtained CT-PA. Inter-reader-agreement was good (k = 0.781). On CT-PA, 13.2% of COVID-19 patients presented with PE whereas in the control-groups prevalence of PE was 9.1% and 8.9%, respectively (p = 0.452). Up to 50% of COVID-19 patients showed changes typical for OP. 21.1% of COVID-19 patients suspected with PE showed subpleural wedge-shaped consolidation resembling infarct pneumonia, while only 13.2% showed visible filling defects of the pulmonary artery branches on CT-PA. CONCLUSION: Despite the reported hypercoagulability in critically ill patients with COVID-19, we did not encounter higher prevalence of PE in our patient cohort compared to the control cohorts. However, patients with suspected PE showed a higher prevalence of lung changes, resembling patterns of infarct pneumonia or OP and CT-signs of pulmonary-artery hypertension.

Postoperative cavitating infarction following lobectomy: the importance of variant pulmonary anatomy.

A 75-year-old woman was admitted to hospital with haemoptysis, fever and shortness of breath. She had undergone a right video-assisted thoracoscopic surgery upper lobectomy for an apical lung cancer 4 weeks earlier, and had been treated with antibiotics for 1 week prior to admission for a suspected postoperative lung abscess. Review of preoperative imaging found that she possessed a lobar pulmonary artery variant, with postoperative imaging confirming that the right lower lobe segmental pulmonary artery had been divided alongside the upper lobe vessels. The diagnosis of a lung abscess was thus revised to a cavitating pulmonary infarct. There are numerous variations of the pulmonary vasculature, all of which have the potential to cause a range of serious vascular complications if not appreciated preoperatively. Measures to mitigate the risk of complications resulting from vascular anomalies should be considered by both radiologists and surgeons, with effective lines of communication essential to safe working.

Multimodal indirect imaging signs of pulmonary embolism.

The clinical diagnosis of pulmonary embolism is often difficult, as symptoms range from syncope and chest pain to shock and sudden death. Adding complexity to this picture, some patients with non-diagnosed pulmonary embolism may undergo unenhanced imaging examinations for a number of reasons, including the prevention of contrast medium-related nephrotoxicity, anaphylactic/anaphylactoid reactions and nephrogenic systemic fibrosis, as well as due to patients' refusal or lack of venous access. In this context, radiologists' awareness and recognition of indirect signs are cornerstones in the diagnosis of pulmonary embolism. This article describes the indirect signs of pulmonary embolism on chest X-ray, unenhanced CT, and MRI.

Incidence and morphological characteristics of the reversed halo sign in patients with acute pulmonary embolism and pulmonary infarction undergoing computed tomography angiography of the pulmonary arteries.

OBJECTIVE: To determine the incidence of the reversed halo sign (RHS) in patients with pulmonary infarction (PI) due to acute pulmonary embolism (PE), detected by computed tomography angiography (CTA) of the pulmonary arteries, and to describe the main morphological features of the RHS. METHODS: We evaluated 993 CTA scans, stratified by the risk of PE, performed between January of 2010 and December of 2014. Although PE was detected in 164 scans (16.5%), three of those scans were excluded because of respiratory motion artifacts. Of the remaining 161 scans, 75 (46.6%) showed lesions consistent with PI, totaling 86 lesions. Among those lesions, the RHS was seen in 33 (38.4%, in 29 patients). RESULTS: Among the 29 patients with scans showing lesions characteristic of PI with the RHS, 25 (86.2%) had a single lesion and 4 (13.8%) had two, totaling 33 lesions. In all cases, the RHS was in a subpleural location. To standardize the analysis, all images were interpreted in the axial plane. Among those 33 lesions, the RHS was in the right lower lobe in 17 (51.5%), in the left lower lobe in 10 (30.3%), in the lingula in 5 (15.2%), and in the right upper lobe in 1 (3.0%). Among those same 33 lesions, areas of low attenuation were seen in 29 (87.9%). The RHS was oval in 24 (72.7%) of the cases and round in 9 (27.3%). Pleural effusion was seen in 21 (72.4%) of the 29 patients with PI and the RHS. CONCLUSIONS: A diagnosis of PE should be considered when there are findings such as those described here, even in patients with nonspecific clinical symptoms.