Abstract:• Chronic thromboembolic pulmonary hypertension (CTEPH) is potentially curable by surgery. • The triage of patients with pulmonary hypertension currently relies on scintigraphy. • Dual-energy CT (DECT) can provide standard diagnostic information and lung perfusion from a single acquisition. • There is excellent agreement between DECT perfusion and scintigraphy in separating CTEPH and non-CTEPH patients.
“…Thus, it is tempting to speculate that the vascular tree-in-bud pattern in COVID-19 pneumonia may be an important CT marker of immunothrombosis and angiogenesis. The DECT scanning technique, although lacking a routine role in the imaging of lung disease, has certainly attracted attention as an alternative means of assessing pulmonary perfusion in acute and chronic thromboembolic disease (23)(24)(25). In the specific context of chronic thromboembolic disease, there is high concordance between findings on DECT and traditional ventilation-perfusion imaging (24,25).…”
Section: Discussionmentioning
confidence: 99%
“…The DECT scanning technique, although lacking a routine role in the imaging of lung disease, has certainly attracted attention as an alternative means of assessing pulmonary perfusion in acute and chronic thromboembolic disease ( 23 – 25 ). In the specific context of chronic thromboembolic disease, there is high concordance between findings on DECT and traditional ventilation-perfusion imaging ( 24 , 25 ). Indeed, patterns of perfusion abnormality appear to differ significantly between chronic thromboembolic disease and patients with pulmonary arterial hypertension ( 24 ).…”
Rationale: Clinical and epidemiologic data in coronavirus disease (COVID-19) have accrued rapidly since the outbreak, but few address the underlying pathophysiology. Objectives: To ascertain the physiologic, hematologic, and imaging basis of lung injury in severe COVID-19 pneumonia. Methods: Clinical, physiologic, and laboratory data were collated. Radiologic (computed tomography (CT) pulmonary angiography [n = 39] and dual-energy CT [DECT, n = 20]) studies were evaluated: observers quantified CT patterns (including the extent of abnormal lung and the presence and extent of dilated peripheral vessels) and perfusion defects on DECT. Coagulation status was assessed using thromboelastography. Measurements and Results: In 39 consecutive patients (male: female, 32:7; mean age, 53 6 10 yr [range, 29-79 yr]; Black and minority ethnic, n = 25 [64%]), there was a significant vascular perfusion abnormality and increased physiologic dead space (dynamic compliance, 33.7 6 14.7 ml/cm H 2 O; Murray lung injury score, 3.14 6 0.53; mean ventilatory ratios, 2.6 6 0.8) with evidence of hypercoagulability and fibrinolytic "shutdown". The mean CT extent (6SD) of normally aerated lung, ground-glass opacification, and dense parenchymal opacification were 23.5 6 16.7%, 36.3 6 24.7%, and 42.7 6 27.1%, respectively. Dilated peripheral vessels were present in 21/33 (63.6%) patients with at least two assessable lobes (including 10/21 [47.6%] with no evidence of acute pulmonary emboli). Perfusion defects on DECT (assessable in 18/20 [90%]) were present in all patients (wedge-shaped, n = 3; mottled, n = 9; mixed pattern, n = 6). Conclusions: Physiologic, hematologic, and imaging data show not only the presence of a hypercoagulable phenotype in severe COVID-19 pneumonia but also markedly impaired pulmonary perfusion likely caused by pulmonary angiopathy and thrombosis.
“…Thus, it is tempting to speculate that the vascular tree-in-bud pattern in COVID-19 pneumonia may be an important CT marker of immunothrombosis and angiogenesis. The DECT scanning technique, although lacking a routine role in the imaging of lung disease, has certainly attracted attention as an alternative means of assessing pulmonary perfusion in acute and chronic thromboembolic disease (23)(24)(25). In the specific context of chronic thromboembolic disease, there is high concordance between findings on DECT and traditional ventilation-perfusion imaging (24,25).…”
Section: Discussionmentioning
confidence: 99%
“…The DECT scanning technique, although lacking a routine role in the imaging of lung disease, has certainly attracted attention as an alternative means of assessing pulmonary perfusion in acute and chronic thromboembolic disease ( 23 – 25 ). In the specific context of chronic thromboembolic disease, there is high concordance between findings on DECT and traditional ventilation-perfusion imaging ( 24 , 25 ). Indeed, patterns of perfusion abnormality appear to differ significantly between chronic thromboembolic disease and patients with pulmonary arterial hypertension ( 24 ).…”
Rationale: Clinical and epidemiologic data in coronavirus disease (COVID-19) have accrued rapidly since the outbreak, but few address the underlying pathophysiology. Objectives: To ascertain the physiologic, hematologic, and imaging basis of lung injury in severe COVID-19 pneumonia. Methods: Clinical, physiologic, and laboratory data were collated. Radiologic (computed tomography (CT) pulmonary angiography [n = 39] and dual-energy CT [DECT, n = 20]) studies were evaluated: observers quantified CT patterns (including the extent of abnormal lung and the presence and extent of dilated peripheral vessels) and perfusion defects on DECT. Coagulation status was assessed using thromboelastography. Measurements and Results: In 39 consecutive patients (male: female, 32:7; mean age, 53 6 10 yr [range, 29-79 yr]; Black and minority ethnic, n = 25 [64%]), there was a significant vascular perfusion abnormality and increased physiologic dead space (dynamic compliance, 33.7 6 14.7 ml/cm H 2 O; Murray lung injury score, 3.14 6 0.53; mean ventilatory ratios, 2.6 6 0.8) with evidence of hypercoagulability and fibrinolytic "shutdown". The mean CT extent (6SD) of normally aerated lung, ground-glass opacification, and dense parenchymal opacification were 23.5 6 16.7%, 36.3 6 24.7%, and 42.7 6 27.1%, respectively. Dilated peripheral vessels were present in 21/33 (63.6%) patients with at least two assessable lobes (including 10/21 [47.6%] with no evidence of acute pulmonary emboli). Perfusion defects on DECT (assessable in 18/20 [90%]) were present in all patients (wedge-shaped, n = 3; mottled, n = 9; mixed pattern, n = 6). Conclusions: Physiologic, hematologic, and imaging data show not only the presence of a hypercoagulable phenotype in severe COVID-19 pneumonia but also markedly impaired pulmonary perfusion likely caused by pulmonary angiopathy and thrombosis.
Background:
To determine the diagnostic accuracy of techniques with chronic thromboembolic pulmonary hypertension (CTEPH) patients via a protocol for systemic review and network meta-analysis.
Methods:
We will search PubMed, EMBASE, Web of Science, and Google Scholar from inception to October 1, 2018. The reference lists of the retrieved articles are also consulted. Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) will be used to assess the risk of bias in each study. The direct meta-analyses, network meta-analyses, and ranking of competing diagnostic tests will be used by STATA 12.0 and WINBUGS 1.4. Heterogeneity and inconsistency are assessed.
Results:
This study is ongoing, will be submitted to a peer-reviewed journal publication once completed.
Conclusion:
This study will provide a comprehensive evidence summary of diagnostic test accuracy in detecting the CTEPH, and can help patients and clinicians to select appropriate or best diagnostic test.
Ethics and Communication:
No ethical approval and patient consent are required, because it is based on published researches.
PROSPERO registration number:
CRD42019121279.
“…Hence, lung abnormalities appear dark on PBV maps. PBV maps can also be merged with conventional CT images to better analyze the lungs’ form and function [ 75 , 76 ]. Fig.…”
Section: Ct Pulmonary Angiography For Pre-procedural Planningmentioning
The manuscript discusses the application of CT pulmonary angiography, ventilation-perfusion scan, and magnetic resonance angiography to detect acute pulmonary embolism and to plan endovascular therapy. CT pulmonary angiography offers high accuracy, speed of acquisition, and widespread availability when applied to acute pulmonary embolism detection. This imaging modality also aids the planning of endovascular therapy by visualizing the number and distribution of emboli, determining ideal intra-procedural catheter position for treatment, and signs of right heart strain. Ventilation-perfusion scan and magnetic resonance angiography with and without contrast enhancement can also aid in the detection and pre-procedural planning of endovascular therapy in patients who are not candidates for CT pulmonary angiography.
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