Pulmonary hypertension leads to a loss of gravity dependent redistribution of regional lung perfusion: a SPECT/CT study

Heart ◽  
2013 ◽  
Vol 100 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Edmund MT Lau ◽  
Dale L Bailey ◽  
Elizabeth A Bailey ◽  
Paul J Torzillo ◽  
Paul J Roach ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Lung Perfusion ◽  
Regional Lung

scholarly journals EXPRESS: Rapid dynamic bedside assessment of pulmonary perfusion defect by electrical impedance tomography in a patient with acute massive pulmonary embolism

2020 ◽  
pp. 204589402098404
Author(s):  
Siyi Yuan ◽  
Huaiwu He ◽  
Yun Long ◽  
Yi Chi ◽  
Inéz Frerichs ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Electrical Impedance Tomography ◽  
Perfusion Defect ◽  
Electrical Impedance ◽  
Massive Pulmonary Embolism ◽  
Lung Perfusion ◽  
Regional Perfusion ◽  
Pulmonary Perfusion ◽  
Impedance Tomography ◽  
Regional Lung

Background: Several animal studies have shown that regional lung perfusion could be effectively estimated by the hypertonic saline contrast electrical impedance tomography (EIT) method. Here, we reported an application of this method to dynamically assess regional pulmonary perfusion defect in a patient with acute massive pulmonary embolism. Case presentation: A 68-year-old man experienced sudden dyspnea and cardiac arrest during out-of-bed physical activity on the first day after partial mediastinal tumor resection. Acute pulmonary embolism (PE) was suspected due to acute enlargement of right heart and fixed inferior venous cava measured with bedside ultrasound. The computed tomography pulmonary angiography further confirmed large embolism in both left and right main pulmonary arteries and branches. The regional time impedance curves, which were obtained by a bolus of 10ml 10% NaCl through the central venous catheter, were then analyzed to quantitatively assess regional perfusion. Normal ventilation distribution with massive defects in regional perfusion in both lungs was observed, leading to a ventilation-perfusion mismatch and low oxygenation index (PaO2/FiO2=86 mmHg) at the first day of PE. The anticoagulation was performed with heparin, and the patient’s condition (such as shock, dyspnea, hypoxemia etc.), regional lung perfusion defect and ventilation-perfusion mismatch continuously improved in the following days. Conclusions: This case implies that EIT might have the potential to assess and monitor regional perfusion for rapid diagnosis of fatal PE in clinical practice.

Development of a method to measure regional perfusion of the lung in anesthetized ponies using computed tomography angiography and the maximum slope model

2022 ◽  
pp. 1-9
Author(s):  
Adam Auckburally ◽  
Görel Nyman ◽  
Maja K. Wiklund ◽  
Anna K. Straube ◽  
Gaetano Perchiazzi ◽  
...  
Keyword(s):  
Ct Angiography ◽  
Lung Tissue ◽  
Lung Perfusion ◽  
Therapeutic Interventions ◽  
Maximum Slope ◽  
Mechanically Ventilated ◽  
Regional Lung ◽  
Microsphere Method ◽  
Perfusion Measurements ◽  
Spontaneously Breathing

Abstract OBJECTIVE To develop a method based on CT angiography and the maximum slope model (MSM) to measure regional lung perfusion in anesthetized ponies. ANIMALS 6 ponies. PROCEDURES Anesthetized ponies were positioned in dorsal recumbency in the CT gantry. Contrast was injected, and the lungs were imaged while ponies were breathing spontaneously and while they were mechanically ventilated. Two observers delineated regions of interest in aerated and atelectatic lung, and perfusion in those regions was calculated with the MSM. Measurements obtained with a computerized method were compared with manual measurements, and computerized measurements were compared with previously reported measurements obtained with microspheres. RESULTS Perfusion measurements obtained with the MSM were similar to previously reported values obtained with the microsphere method. While ponies were spontaneously breathing, mean ± SD perfusion for aerated and atelectatic lung regions were 4.0 ± 1.9 and 5.0 ± 1.2 mL/min/g of lung tissue, respectively. During mechanical ventilation, values were 4.6 ± 1.2 and 2.7 ± 0.7 mL/min/g of lung tissue at end expiration and 4.1 ± 0.5 and 2.7 ± 0.6 mL/min/g of lung tissue at peak inspiration. Intraobserver agreement was acceptable, but interobserver agreement was lower. Computerized measurements compared well with manual measurements. CLINICAL RELEVANCE Findings showed that CT angiography and the MSM could be used to measure regional lung perfusion in dorsally recumbent anesthetized ponies. Measurements are repeatable, suggesting that the method could be used to determine efficacy of therapeutic interventions to improve ventilation-perfusion matching and for other studies for which measurement of regional lung perfusion is necessary.

scholarly journals Comparison of regional lung perfusion response on longitudinal MAA SPECT/CT in lung cancer patients treated with and without functional tissue-avoidance radiation therapy

2019 ◽  
Vol 92 (1103) ◽  
pp. 20190174 ◽  
Author(s):  
Hannah Mary T Thomas ◽  
Jing Zeng ◽  
Howard J Lee, Jr ◽  
Balu Krishna Sasidharan ◽  
Paul E Kinahan ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Radiation Therapy ◽  
Cancer Patients ◽  
Dose Response ◽  
Lung Perfusion ◽  
Ct Scans ◽  
Lung Dose ◽  
Lung Cancer Patients ◽  
Response Slope ◽  
Regional Lung

Objective: The effect of functional lung avoidance planning on radiation dose-dependent changes in regional lung perfusion is unknown. We characterized dose-perfusion response on longitudinal perfusion single photon emission computed tomography (SPECT)/CT in two cohorts of lung cancer patients treated with and without functional lung avoidance techniques. Methods: The study included 28 primary lung cancer patients: 20 from interventional (NCT02773238) (FLARE-RT) and eight from observational (NCT01982123) (LUNG-RT) clinical trials. FLARE-RT treatment plans included perfused lung dose constraints while LUNG-RT plans adhered to clinical standards. Pre- and 3 month post-treatment macro-aggregated albumin (MAA) SPECT/CT scans were rigidly co-registered to planning four-dimensional CT scans. Tumour-subtracted lung dose was converted to EQD2 and sorted into 5 Gy bins. Mean dose and percent change between pre/post-RT MAA-SPECT uptake (%ΔPERF), normalized to total tumour-subtracted lung uptake, were calculated in each binned dose region. Perfusion frequency histograms of pre/post-RT MAA-SPECT were analyzed. Dose–response data were parameterized by sigmoid logistic functions to estimate maximum perfusion increase (%ΔPERFmaxincrease), maximum perfusion decrease (%ΔPERFmaxdecrease), dose midpoint (Dmid), and dose-response slope (k). Results: Differences in MAA perfusion frequency distribution shape between time points were observed in 11/20 (55%) FLARE-RT and 2/8 (25%) LUNG-RT patients (p < 0.05). FLARE-RT dose response was characterized by >10% perfusion increase in the 0–5 Gy dose bin for 8/20 patients (%ΔPERFmaxincrease = 10–40%), which was not observed in any LUNG-RT patients (p = 0.03). The dose midpoint Dmid at which relative perfusion declined by 50% trended higher in FLARE-RT compared to LUNG-RT cohorts (35 GyEQD2 vs 21 GyEQD2, p = 0.09), while the dose-response slope k was similar between FLARE-RT and LUNG-RT cohorts (3.1–3.2, p = 0.86). Conclusion: Functional lung avoidance planning may promote increased post-treatment perfusion in low dose regions for select patients, though inter-patient variability remains high in unbalanced cohorts. These preliminary findings form testable hypotheses that warrant subsequent validation in larger cohorts within randomized or case-matched control investigations. Advances in knowledge: This novel preliminary study reports differences in dose-response relationships between patients receiving functional lung avoidance radiation therapy (FLARE-RT) and those receiving conventionally planned radiation therapy (LUNG-RT). Following further validation and testing of these effects in larger patient populations, individualized estimation of regional lung perfusion dose-response may help refine future risk-adaptive strategies to minimize lung function deficits and toxicity incidence.

Radiation-Induced Reductions in Regional Lung Perfusion: 0.1–12 Year Data From a Prospective Clinical Study

2010 ◽  
Vol 76 (2) ◽  
pp. 425-432 ◽  
Author(s):  
Junan Zhang ◽  
Jinli Ma ◽  
Sumin Zhou ◽  
Jessica L. Hubbs ◽  
Terence Z. Wong ◽  
...  
Keyword(s):  
Clinical Study ◽  
Lung Perfusion ◽  
Prospective Clinical Study ◽  
Regional Lung ◽  
Radiation Induced

scholarly journals Frequency of computed tomography abnormalities in patients with chronic thromboembolic pulmonary hypertension: a comparative study between lung perfusion scan and computed tomography pulmonary angiography

2021 ◽  
Vol 16 ◽  
Author(s):  
Ahmed Fathala ◽  
Alaa Aldurabi
Keyword(s):  
Computed Tomography ◽  
Pulmonary Hypertension ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Pulmonary Angiography ◽  
Lung Perfusion ◽  
Computed Tomography Pulmonary Angiography ◽  
Thromboembolic Pulmonary Hypertension ◽  
Study Population ◽  
The Mean ◽  
Parenchymal Lung

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the leading causes of pulmonary hypertension. Diagnosis of CTEPH can be established using various imaging techniques, including ventilation-perfusion scintigraphy (VQ) and multidetector computed tomography pulmonary angiography (CTPA). The aim of this study was to determine the frequency of direct pulmonary vascular, parenchymal lung, and cardiac abnormalities on CTPA in patients with CTEPH and to compare the diagnostic accuracy of both VQ scan CTPA in detecting CTEPH.Methods: we retrospectively included 54 patients who had been referred for pulmonary hypertension service (20 males, 34 females). All patients had VQ scan and CTPA within 15 days and underwent pulmonary artery endarterectomy (PEA) thereafter. VQ scan were reported according to modified PIOPED (Prospective Investigation of Pulmonary Embolism Diagnosis) criteria. CTPA was considered as diagnostic for CTEPH if it showed presence of thrombus, webs, stenosis, or perfusion lung abnormalities.Results: The mean age of the study population was 41±10 years. The mean pulmonary artery pressure was 53±13 mmHg. Fifty-three of 54 patients in the study population had high probability VQ scan and one patient had intermediate probability. CTPA was suggestive of CTEPH in all patients. The most frequent CTPA findings in the central pulmonary arteries and peripheral arteries were presence of thrombotic materials, abnormal vessel tapering and abrupt vessels-cut off (76% vs 65%, 67% vs 48%, and 48% vs 22%), respectively. The mosaic lung perfusion was present in 78% in the patients, and various cardiac morphology abnormalities were presents and most common was abnormal right to left ventricle ratio, 69%.Conclusion: Our findings indicate that both VQ scan and CTPA are highly sensitive for the detection of CTEPH confirmed by PEA. Most CTEPH patients had several pulmonary vascular, parenchymal lung and cardiac abnormalities. There was no sign with 100% sensitivity on CTPA for CTEPH detection.

Sign in / Sign up

Export Citation Format

Share Document