"in COVID-19 cohorts, pulmonary artery filling defects were identified in approximately 36% of patients undergoing CTPA, far exceeding the pre-pandemic yield of 12–17% 4,6"
"retrospective imaging reviews of post-radiation therapy patients identified in situ thrombosis in cohorts where PE had not been formally suspected 7"
"haemoptysis (particularly in post-radiation or aspergillosis-associated cases) 7"
"There is no validated clinical decision rule that reliably distinguishes ISPAT from thromboembolic PE pre-imaging 1. Contextual clues suggesting ISPAT over PE include:"
"post-pneumonectomy pulmonary artery stump thrombosis 4"
"radiation therapy (RT) to the thorax: particularly in lung cancer and mesothelioma; thrombosis may develop months to years post-RT 7"
"response to anticoagulation may be incomplete: cases of persistent thrombus despite adequate therapy have been documented, particularly post-RT and post-lobectomy 7"
"response to anticoagulation may be incomplete: cases of persistent thrombus despite adequate therapy have been documented, particularly post-RT and post-lobectomy 7"
"post-radiation ISPAT: often indolent course; thrombus may be stable or slowly progressive over months to years; haemodynamic impact is typically limited 7"
"chronic thromboembolic PE / CTEPH: organised, eccentric thrombus; mosaic attenuation; dilated bronchial arteries; pulmonary artery webs and bands; post-obstructive changes 1"
"in COVID-19 cohorts, pulmonary artery filling defects were identified in approximately 36% of patients undergoing CTPA, far exceeding the pre-pandemic yield of 12–17% 4,6"
"clinical context: active infection, inflammatory state, prior RT, structural cardiac/pulmonary disease 4"
"underlying severe PAH or congenital cardiac disease 3,10"
"SARS-CoV-2 directly infects pulmonary vascular endothelium, triggering cytokine release and increased capillary permeability 5"
"Histopathological analyses confirm pulmonary immunothrombosis in over 90% of severe COVID-19 cases, independent of disease duration and substantially more prevalent than in influenza. It is distinct from overt disseminated intravascular coagulation (DIC) and has been termed ‘pulmonary immunocoagulopathy’ (PIC) 6."
"COVID-19 (SARS-CoV-2): the most extensively studied association; immunothrombosis is the dominant mechanism 5,6"
"COVID-19: therapeutic anticoagulation was the subject of multiple RCTs (RECOVERY, MICHELLE trial; Lancet 2022), with evolving recommendations stratified by disease severity 9"
"Reserved for haemodynamically significant cases; evidence base is drawn from submassive/massive PE literature. ISPAT typically presents with lower clot burden and lower RV strain, making aggressive intervention less frequently required 1,4."
Expected headings
"Blood stasis"
"Endothelial dysfunction"
"Immunothrombosis"
"Inflammatory and infectious"
"Haematological"
"Structural and mechanical"
"Iatrogenic and acquired"
"Parenchymal lung disease"
"Trauma"
"Echocardiography"
"Anticoagulation"
"Treatment of underlying condition"
"Immunomodulation"
"Thrombolysis and thrombectomy"
"Prognosis"
"Key diagnostic point: there is currently no gold standard diagnostic test for ISPAT. The diagnosis is established by integrating clinical context, cross-sectional imaging, and exclusion of a peripheral DVT source 1,4:"
"elevated hemidiaphragm: a recently described association 2"
"There is no validated clinical decision rule that reliably distinguishes ISPAT from thromboembolic PE pre-imaging 1. Contextual clues suggesting ISPAT over PE include:"
"COVID-19 (SARS-CoV-2): the most extensively studied association; immunothrombosis is the dominant mechanism 5,6"
"sickle cell disease: particularly during acute chest syndrome (ACS); associated with elevated platelet counts and lower haemolysis rates 4"
"Eisenmenger syndrome: a well-recognised cause of proximal pulmonary artery thrombosis; biventricular dysfunction, shear stress and slow flow create conditions for in situ clot formation in the central pulmonary arteries, distinct from peripheral embolic disease 10"
"radiation therapy (RT) to the thorax: particularly in lung cancer and mesothelioma; thrombosis may develop months to years post-RT 7"
"non-specific; chest radiograph may demonstrate underlying parenchymal disease (consolidation, atelectasis, fibrosis, radiation change) without specific features of ISPAT itself"
"V/Q scintigraphy may demonstrate matched or mismatched perfusion defects; not well-validated for distinguishing ISPAT from embolic PE in the current literature 1"
"emerging role in confirming LFSA: absence of the filling defect on MRI of the same territory supports stasis artifact rather than true thrombus; MR pulmonary angiography (MRPA) is not routinely used in acute assessment 2"
"COVID-19: therapeutic anticoagulation was the subject of multiple RCTs (RECOVERY, MICHELLE trial; Lancet 2022), with evolving recommendations stratified by disease severity 9"
"Reserved for haemodynamically significant cases; evidence base is drawn from submassive/massive PE literature. ISPAT typically presents with lower clot burden and lower RV strain, making aggressive intervention less frequently required 1,4."
"COVID-19-associated immunothrombosis: in-hospital mortality is driven predominantly by respiratory failure and multiorgan dysfunction; the contribution of ISPAT per se is difficult to isolate 6"
"post-radiation ISPAT: often indolent course; thrombus may be stable or slowly progressive over months to years; haemodynamic impact is typically limited 7"
"post-radiation ISPAT: often indolent course; thrombus may be stable or slowly progressive over months to years; haemodynamic impact is typically limited 7"
"parenchymal lung disease: thrombus stability or resolution varies; anticoagulation response is inconsistent 2"
"acute thromboembolic PE: DVT identified on lower-limb imaging; clot in non-diseased lung zones; higher clot burden; greater right ventricular strain; typically responds to anticoagulation 1,4"
"acute thromboembolic PE: DVT identified on lower-limb imaging; clot in non-diseased lung zones; higher clot burden; greater right ventricular strain; typically responds to anticoagulation 1,4"
"acute thromboembolic PE: DVT identified on lower-limb imaging; clot in non-diseased lung zones; higher clot burden; greater right ventricular strain; typically responds to anticoagulation 1,4"
"acute thromboembolic PE: DVT identified on lower-limb imaging; clot in non-diseased lung zones; higher clot burden; greater right ventricular strain; typically responds to anticoagulation 1,4"
"chronic thromboembolic PE / CTEPH: organised, eccentric thrombus; mosaic attenuation; dilated bronchial arteries; pulmonary artery webs and bands; post-obstructive changes 1"
"chronic thromboembolic PE / CTEPH: organised, eccentric thrombus; mosaic attenuation; dilated bronchial arteries; pulmonary artery webs and bands; post-obstructive changes 1"
"chronic thromboembolic PE / CTEPH: organised, eccentric thrombus; mosaic attenuation; dilated bronchial arteries; pulmonary artery webs and bands; post-obstructive changes 1"
"chronic thromboembolic PE / CTEPH: organised, eccentric thrombus; mosaic attenuation; dilated bronchial arteries; pulmonary artery webs and bands; post-obstructive changes 1"
"low-flow stasis artifact (LFSA): absent on MRI or abdominal CT of same territory; no true thrombus present; conservative management appropriate. Differentiation from true ISPAT may be clinically important 2"
"low-flow stasis artifact (LFSA): absent on MRI or abdominal CT of same territory; no true thrombus present; conservative management appropriate. Differentiation from true ISPAT may be clinically important 2"
"tumour-related occlusion: primary sarcoma of the pulmonary artery (rare); enhancing intraluminal mass; associated mediastinal invasion"
"tumour-related occlusion: primary sarcoma of the pulmonary artery (rare); enhancing intraluminal mass; associated mediastinal invasion"
"pulmonary artery vasculitis: elevated systemic inflammatory markers; associated systemic vasculitis features; vessel wall thickening on cross-sectional imaging"
"pulmonary artery vasculitis: elevated systemic inflammatory markers; associated systemic vasculitis features; vessel wall thickening on cross-sectional imaging"