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Victor M, Xin Y, Alcala G, Gaulton T, Costa E, Winkler T, Berra L, Amato M, Cereda M. First-Pass Kinetics Model to Estimate Pulmonary Perfusion by Electrical Impedance Tomography During Uninterrupted Breathing. Am J Respir Crit Care Med 2024; 209:1263-1265. [PMID: 38412326 PMCID: PMC11146534 DOI: 10.1164/rccm.202310-1919le] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 02/27/2024] [Indexed: 02/29/2024] Open
Affiliation(s)
- Marcus Victor
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School, Boston, Massachusetts
- Electronics Engineering Division, Aeronautics Institute of Technology, Sao Paulo, Brazil; and
| | - Yi Xin
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School, Boston, Massachusetts
| | - Glasiele Alcala
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School, Boston, Massachusetts
| | - Timothy Gaulton
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School, Boston, Massachusetts
| | - Eduardo Costa
- Disciplina de Pneumologia, Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Sao Paulo, Brazil
| | - Tilo Winkler
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School, Boston, Massachusetts
| | - Lorenzo Berra
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School, Boston, Massachusetts
| | - Marcelo Amato
- Disciplina de Pneumologia, Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Sao Paulo, Brazil
| | - Maurizio Cereda
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School, Boston, Massachusetts
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Martin KT, Xin Y, Gaulton TG, Victor M, Santiago RR, Kim T, Morais CCA, Kazimi AA, Connell M, Gerard SE, Herrmann J, Mueller AL, Lenart A, Shen J, Khan SS, Petrov M, Reutlinger K, Rozenberg K, Amato M, Berra L, Cereda M. Electrical Impedance Tomography Identifies Evolution of Regional Perfusion in a Porcine Model of Acute Respiratory Distress Syndrome. Anesthesiology 2023; 139:815-826. [PMID: 37566686 PMCID: PMC10840641 DOI: 10.1097/aln.0000000000004731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2023]
Abstract
BACKGROUND Bedside electrical impedance tomography could be useful to visualize evolving pulmonary perfusion distributions when acute respiratory distress syndrome worsens or in response to ventilatory and positional therapies. In experimental acute respiratory distress syndrome, this study evaluated the agreement of electrical impedance tomography and dynamic contrast-enhanced computed tomography perfusion distributions at two injury time points and in response to increased positive end-expiratory pressure (PEEP) and prone position. METHODS Eleven mechanically ventilated (VT 8 ml · kg-1) Yorkshire pigs (five male, six female) received bronchial hydrochloric acid (3.5 ml · kg-1) to invoke lung injury. Electrical impedance tomography and computed tomography perfusion images were obtained at 2 h (early injury) and 24 h (late injury) after injury in supine position with PEEP 5 and 10 cm H2O. In eight animals, electrical impedance tomography and computed tomography perfusion imaging were also conducted in the prone position. Electrical impedance tomography perfusion (QEIT) and computed tomography perfusion (QCT) values (as percentages of image total) were compared in eight vertical regions across injury stages, levels of PEEP, and body positions using mixed-effects linear regression. The primary outcome was agreement between QEIT and QCT, defined using limits of agreement and Pearson correlation coefficient. RESULTS Pao2/Fio2 decreased over the course of the experiment (healthy to early injury, -253 [95% CI, -317 to -189]; early to late injury, -88 [95% CI, -151 to -24]). The limits of agreement between QEIT and QCT were -4.66% and 4.73% for the middle 50% quantile of average regional perfusion, and the correlation coefficient was 0.88 (95% CI, 0.86 to 0.90]; P < 0.001). Electrical impedance tomography and computed tomography showed similar perfusion redistributions over injury stages and in response to increased PEEP. QEIT redistributions after positional therapy underestimated QCT in ventral regions and overestimated QCT in dorsal regions. CONCLUSIONS Electrical impedance tomography closely approximated computed tomography perfusion measures in experimental acute respiratory distress syndrome, in the supine position, over injury progression and with increased PEEP. Further validation is needed to determine the accuracy of electrical impedance tomography in measuring perfusion redistributions after positional changes. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Kevin T Martin
- Department of Anesthesia and Perioperative Care, University of California San Francisco, CA, USA
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Yi Xin
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Timothy G Gaulton
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Marcus Victor
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
- Electronics Engineering Division, Aeronautics Institute of Technology, São Paulo, Brazil
| | - Roberta R Santiago
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Taehwan Kim
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Caio C A Morais
- Department of Physical Therapy, Federal University of Pernambuco, Recife, Brazil
| | - Aubrey A Kazimi
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Marc Connell
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
- University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Sarah E Gerard
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA
| | - Jacob Herrmann
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA
| | - Ariel L Mueller
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Austin Lenart
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Jiacheng Shen
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Sherbano S Khan
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Mihail Petrov
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Kristan Reutlinger
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Karina Rozenberg
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Marcelo Amato
- Department of Cardio-Pulmonary, University of São Paulo, São Paulo, Brazil
| | - Lorenzo Berra
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
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Bogot NR, Steiner R, Helviz Y, Weiss C, Cherniavsky K, Pichkhadze O, Ball L, Frank Y, Levin P, Pelosi P, Benjaminov O, Einav S. Distribution of Aeration and Pulmonary Blood Volume in Healthy, ARDS and COVID-19 Lungs: A Dual-Energy Computed Tomography Retrospective Cohort Study. Acad Radiol 2023; 30:2548-2556. [PMID: 36966073 PMCID: PMC10035816 DOI: 10.1016/j.acra.2023.01.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/20/2023]
Abstract
RATIONALE AND OBJECTIVES Few reports have studied lung aeration and perfusion in normal lungs, COVID-19, and ARDS from other causes (NC-ARDS) using dual-energy computed tomography pulmonary angiograms (DE-CTPA). To describe lung aeration and blood-volume distribution using DE-CTPAs of patients with NC-ARDS, COVID-19, and controls with a normal DE-CTPA ("healthy lungs"). We hypothesized that each of these conditions has unique ranges of aeration and pulmonary blood volumes. MATERIALS AND METHODS This retrospective, single-center study of DE-CTPAs included patients with COVID-19, NC-ARDS (Berlin criteria), and controls. Patients with macroscopic pulmonary embolisms were excluded. The outcomes studied were the (1) lung blood-volume in areas with different aeration levels (normal, ground glass opacities [GGO], consolidated lung) and (2) aeration/blood-volume ratios. RESULTS Included were 20 patients with COVID-19 (10 milds, 10 moderate-severe), six with NC-ARDS, and 12 healthy-controls. Lung aeration was lowest in patients with severe COVID-19 24% (IQR13%-31%) followed by those with NC-ARDS 40%(IQR21%-46%). Blood-volume in GGO was lowest in patients with COVID-19 [moderate-severe:-28.6 (IQR-33.1-23.2); mild: -30.1 (IQR-33.3-23.4)] and highest in normally aerated areas in NC-ARDS -37.4 (IQR-52.5-30.2-) and moderate-severe COVID-19 -33.5(IQR-44.2-28.5). The median aeration/blood-volume ratio was lowest in severe COVID-19 but some values overlapped with those observed among patients with NC-ARDS. CONCLUSION Severe COVID-19 disease is associated with low total aerated lung volume and blood-volume in areas with GGO and overall aeration/blood volume ratios, and with high blood volume in normal lung areas. In this hypothesis-generating study, these findings were most pronounced in severe COVID disease. Larger studies are needed to confirm these preliminary findings.
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Affiliation(s)
| | | | - Yigal Helviz
- The Intensive Care Unit, Jerusalem, Israel; The Shaare Zedek Medical Center, Hebrew University Faculty of Medicine, Samuel Byte 12, Jerusalem, Israel
| | - Chedva Weiss
- The Intensive Care Unit, Jerusalem, Israel; Department of pediatrics, Hadassah Medical Center Jerusalem, Jerusalem, Israel
| | | | | | - Lorenzo Ball
- The Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy; Anesthesia and Intensive Care, San Martino Policlinico Hospital, IRCCS for Oncology and Neurosciences, Genoa, Italy
| | - Yigal Frank
- Department of Radiology(,) Jerusalem, Israel
| | - Philip Levin
- The Intensive Care Unit, Jerusalem, Israel; The Shaare Zedek Medical Center, Hebrew University Faculty of Medicine, Samuel Byte 12, Jerusalem, Israel
| | - Paolo Pelosi
- The Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy; Anesthesia and Intensive Care, San Martino Policlinico Hospital, IRCCS for Oncology and Neurosciences, Genoa, Italy
| | | | - Sharon Einav
- The Intensive Care Unit, Jerusalem, Israel; The Shaare Zedek Medical Center, Hebrew University Faculty of Medicine, Samuel Byte 12, Jerusalem, Israel.
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Xin Y, Kim T, Winkler T, Brix G, Gaulton T, Gerard SE, Herrmann J, Martin KT, Victor M, Reutlinger K, Amato M, Berra L, Kalra MK, Cereda M. Improving pulmonary perfusion assessment by dynamic contrast-enhanced computed tomography in an experimental lung injury model. J Appl Physiol (1985) 2023; 134:1496-1507. [PMID: 37167261 PMCID: PMC10228674 DOI: 10.1152/japplphysiol.00159.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/24/2023] [Accepted: 05/11/2023] [Indexed: 05/13/2023] Open
Abstract
Pulmonary perfusion has been poorly characterized in acute respiratory distress syndrome (ARDS). Optimizing protocols to measure pulmonary blood flow (PBF) via dynamic contrast-enhanced (DCE) computed tomography (CT) could improve understanding of how ARDS alters pulmonary perfusion. In this study, comparative evaluations of injection protocols and tracer-kinetic analysis models were performed based on DCE-CT data measured in ventilated pigs with and without lung injury. Ten Yorkshire pigs (five with lung injury, five healthy) were anesthetized, intubated, and mechanically ventilated; lung injury was induced by bronchial hydrochloric acid instillation. Each DCE-CT scan was obtained during a 30-s end-expiratory breath-hold. Reproducibility of PBF measurements was evaluated in three pigs. In eight pigs, undiluted and diluted Isovue-370 were separately injected to evaluate the effect of contrast viscosity on estimated PBF values. PBF was estimated with the peak-enhancement and the steepest-slope approach. Total-lung PBF was estimated in two healthy pigs to compare with cardiac output measured invasively by thermodilution in the pulmonary artery. Repeated measurements in the same animals yielded a good reproducibility of computed PBF maps. Injecting diluted isovue-370 resulted in smaller contrast-time curves in the pulmonary artery (P < 0.01) and vein (P < 0.01) without substantially diminishing peak signal intensity (P = 0.46 in the pulmonary artery) compared with the pure contrast agent since its viscosity is closer to that of blood. As compared with the peak-enhancement model, PBF values estimated by the steepest-slope model with diluted contrast were much closer to the cardiac output (R2 = 0.82) as compared with the peak-enhancement model. DCE-CT using the steepest-slope model and diluted contrast agent provided reliable quantitative estimates of PBF.NEW & NOTEWORTHY Dynamic contrast-enhanced CT using a lower-viscosity contrast agent in combination with tracer-kinetic analysis by the steepest-slope model improves pulmonary blood flow measurements and assessment of regional distributions of lung perfusion.
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Affiliation(s)
- Yi Xin
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States
- Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, Massachusetts, United States
| | - Taehwan Kim
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Tilo Winkler
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States
- Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, Massachusetts, United States
| | - Gunnar Brix
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Salzgitter, Germany
| | - Timothy Gaulton
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States
- Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, Massachusetts, United States
| | - Sarah E Gerard
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States
| | - Jacob Herrmann
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States
| | - Kevin T Martin
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Marcus Victor
- Disciplina de Pneumologia, Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
- Electronics Engineering Division, Aeronautics Institute of Technology, Sao Paulo, Brazil
| | - Kristan Reutlinger
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Marcelo Amato
- Disciplina de Pneumologia, Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Lorenzo Berra
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States
- Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, Massachusetts, United States
| | - Mannudeep K Kalra
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, United States
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, United States
| | - Maurizio Cereda
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States
- Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, Massachusetts, United States
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Ma C, Xu D, Hui Q, Gao X, Peng M. Quantitative Intracerebral Iodine Extravasation in Risk Stratification for Intracranial Hemorrhage in Patients with Acute Ischemic Stroke. AJNR Am J Neuroradiol 2022; 43:1589-1596. [PMID: 36202552 PMCID: PMC9731239 DOI: 10.3174/ajnr.a7671] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/07/2022] [Indexed: 02/01/2023]
Abstract
BACKGROUND AND PURPOSE Intracerebral hemorrhage poses a severe threat to the outcomes in patients with postthrombectomy acute stroke. We aimed to compare the absolute intracerebral iodine concentration and normalized iodine concentration ratio in predicting intracerebral hemorrhage in patients postthrombectomy. MATERIALS AND METHODS Patients with acute anterior circulation large-vessel occlusion who underwent mechanical thrombectomy and had successful recanalization were retrospectively included in the study. Dual-energy CT was performed within 1 hour after mechanical thrombectomy. Postprocessing was performed to measure the absolute intracerebral iodine concentration and the normalized iodine concentration ratio. The correlation between the absolute intracerebral iodine concentration and the normalized iodine concentration ratio was analyzed using the Spearman rank correlation coefficient. We compared the area under the receiver operating characteristic curve of the absolute intracerebral iodine concentration and the normalized iodine concentration ratio using the DeLong test. RESULTS We included 138 patients with successful recanalization. Of 43 patients who did not have parenchymal contrast staining on postthrombectomy dual-energy CT, 5 (11.6%) developed intracerebral hemorrhage. Among patients (95/138, 68.8%) with parenchymal contrast staining, 37 (38.9%, 37/95) developed intracerebral hemorrhage. The absolute intracerebral iodine concentration was significantly correlated with the normalized iodine concentration ratio (ρ = 0.807; 95% CI, 0.718-0.867; P < .001). The cutoffs of the normalized iodine concentration ratio and absolute intracerebral iodine concentration for identifying patients with intracerebral hemorrhage development were 222.8%, with a sensitivity of 67.6% and specificity of 76.4%, and 2.7 mg I/mL, with a sensitivity of 75.7% and specificity of 65.5%, respectively. No significant difference was found between the areas under the receiver operating characteristic curve for the absolute intracerebral iodine concentration and the normalized iodine concentration ratio (0.753 versus 0.738) (P = .694). CONCLUSIONS The hemorrhagic transformation predictive power of the normalized iodine concentration ratio is similar to that of the absolute intracerebral iodine concentration in patients with successful recanalization.
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Affiliation(s)
- C Ma
- From the Departments of Radiology (C.M., Q.H., X.G.)
| | | | - Q Hui
- From the Departments of Radiology (C.M., Q.H., X.G.)
| | - X Gao
- From the Departments of Radiology (C.M., Q.H., X.G.)
| | - M Peng
- Neurology (M.P.), Deyang People's Hospital, Deyang, Sichuan, China
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Ball L, Scaramuzzo G, Herrmann J, Cereda M. Lung aeration, ventilation, and perfusion imaging. Curr Opin Crit Care 2022; 28:302-307. [PMID: 35653251 PMCID: PMC9178949 DOI: 10.1097/mcc.0000000000000942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE OF REVIEW Lung imaging is a cornerstone of the management of patients admitted to the intensive care unit (ICU), providing anatomical and functional information on the respiratory system function. The aim of this review is to provide an overview of mechanisms and applications of conventional and emerging lung imaging techniques in critically ill patients. RECENT FINDINGS Chest radiographs provide information on lung structure and have several limitations in the ICU setting; however, scoring systems can be used to stratify patient severity and predict clinical outcomes. Computed tomography (CT) is the gold standard for assessment of lung aeration but requires moving the patients to the CT facility. Dual-energy CT has been recently applied to simultaneous study of lung aeration and perfusion in patients with respiratory failure. Lung ultrasound has an established role in the routine bedside assessment of ICU patients, but has poor spatial resolution and largely relies on the analysis of artifacts. Electrical impedance tomography is an emerging technique capable of depicting ventilation and perfusion at the bedside and at the regional level. SUMMARY Clinicians should be confident with the technical aspects, indications, and limitations of each lung imaging technique to improve patient care.
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Affiliation(s)
- Lorenzo Ball
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy
- Anesthesia and Intensive Care, Ospedale Policlinico San Martino, IRCCS per l’Oncologia e le Neuroscienze, Genoa, Italy
| | - Gaetano Scaramuzzo
- Department of Translational medicine, University of Ferrara, Ferrara, Italy
- Anesthesia and intensive care, Arcispedale Sant’Anna, Ferrara, Italy
| | - Jake Herrmann
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, United States of America
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Zhao Y, Hubbard L, Malkasian S, Abbona P, Molloi S. Contrast timing optimization of a two-volume dynamic CT pulmonary perfusion technique. Sci Rep 2022; 12:8212. [PMID: 35581304 PMCID: PMC9114423 DOI: 10.1038/s41598-022-12016-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 04/21/2022] [Indexed: 11/12/2022] Open
Abstract
The purpose of this study is to develop and validate an optimal timing protocol for a low-radiation-dose CT pulmonary perfusion technique using only two volume scans. A total of 24 swine (48.5 ± 14.3 kg) underwent contrast-enhanced dynamic CT. Multiple contrast injections were made under different pulmonary perfusion conditions, resulting in a total of 141 complete pulmonary arterial input functions (AIFs). Using all the AIF curves, an optimal contrast timing protocol was developed for a first-pass, two-volume dynamic CT perfusion technique (one at the base and the other at the peak of AIF curve). A subset of swine was used to validate the prospective two-volume pulmonary perfusion technique. The prospective two-volume perfusion measurements were quantitatively compared to the previously validated retrospective perfusion measurements with t-test, linear regression, and Bland–Altman analysis. As a result, the pulmonary artery time-to-peak (\documentclass[12pt]{minimal}
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\begin{document}$${T}_{PA}$$\end{document}TPA) was related to one-half of the contrast injection duration (\documentclass[12pt]{minimal}
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\begin{document}$$\frac{{T}_{Inj}}{2}$$\end{document}TInj2) by \documentclass[12pt]{minimal}
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\begin{document}$${T}_{PA}=1.01\frac{{T}_{Inj}}{2}+1.01$$\end{document}TPA=1.01TInj2+1.01 (r = 0.95). The prospective two-volume perfusion measurements (PPRO) were related to the retrospective measurements (PRETRO) by PPRO = 0.87PRETRO + 0.56 (r = 0.88). The CT dose index and size-specific dose estimate of the two-volume CT technique were estimated to be 28.4 and 47.0 mGy, respectively. The optimal timing protocol can enable an accurate, low-radiation-dose two-volume dynamic CT perfusion technique.
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Affiliation(s)
- Yixiao Zhao
- Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, Irvine, CA, 92697, USA
| | - Logan Hubbard
- Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, Irvine, CA, 92697, USA
| | - Shant Malkasian
- Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, Irvine, CA, 92697, USA
| | - Pablo Abbona
- Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, Irvine, CA, 92697, USA
| | - Sabee Molloi
- Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, Irvine, CA, 92697, USA.
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Lung distribution of gas and blood volume in critically ill COVID-19 patients: a quantitative dual-energy computed tomography study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2021; 25:214. [PMID: 34154635 PMCID: PMC8215486 DOI: 10.1186/s13054-021-03610-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 05/19/2021] [Indexed: 12/17/2022]
Abstract
Background Critically ill COVID-19 patients have pathophysiological lung features characterized by perfusion abnormalities. However, to date no study has evaluated whether the changes in the distribution of pulmonary gas and blood volume are associated with the severity of gas-exchange impairment and the type of respiratory support (non-invasive versus invasive) in patients with severe COVID-19 pneumonia. Methods This was a single-center, retrospective cohort study conducted in a tertiary care hospital in Northern Italy during the first pandemic wave. Pulmonary gas and blood distribution was assessed using a technique for quantitative analysis of dual-energy computed tomography. Lung aeration loss (reflected by percentage of normally aerated lung tissue) and the extent of gas:blood volume mismatch (percentage of non-aerated, perfused lung tissue—shunt; aerated, non-perfused dead space; and non-aerated/non-perfused regions) were evaluated in critically ill COVID-19 patients with different clinical severity as reflected by the need for non-invasive or invasive respiratory support. Results Thirty-five patients admitted to the intensive care unit between February 29th and May 30th, 2020 were included. Patients requiring invasive versus non-invasive mechanical ventilation had both a lower percentage of normally aerated lung tissue (median [interquartile range] 33% [24–49%] vs. 63% [44–68%], p < 0.001); and a larger extent of gas:blood volume mismatch (43% [30–49%] vs. 25% [14–28%], p = 0.001), due to higher shunt (23% [15–32%] vs. 5% [2–16%], p = 0.001) and non-aerated/non perfused regions (5% [3–10%] vs. 1% [0–2%], p = 0.001). The PaO2/FiO2 ratio correlated positively with normally aerated tissue (ρ = 0.730, p < 0.001) and negatively with the extent of gas-blood volume mismatch (ρ = − 0.633, p < 0.001). Conclusions In critically ill patients with severe COVID-19 pneumonia, the need for invasive mechanical ventilation and oxygenation impairment were associated with loss of aeration and the extent of gas:blood volume mismatch. Graphic abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13054-021-03610-9.
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Abstract
Supplemental Digital Content is available in the text. Determine the intra-tidal regional gas and blood volume distributions at different levels of atelectasis in experimental lung injury. Test the hypotheses that pulmonary aeration and blood volume matching is reduced during inspiration in the setting of minimal tidal recruitment/derecruitment and that this mismatching is an important determinant of hypoxemia.
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Ridge CA, Desai SR, Jeyin N, Mahon C, Lother DL, Mirsadraee S, Semple T, Price S, Bleakley C, Arachchillage DJ, Shaw E, Patel BV, Padley SPG, Devaraj A. Dual-Energy CT Pulmonary Angiography (DECTPA) Quantifies Vasculopathy in Severe COVID-19 Pneumonia. Radiol Cardiothorac Imaging 2020; 2:e200428. [PMID: 33778632 PMCID: PMC7605077 DOI: 10.1148/ryct.2020200428] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND The role of dual energy computed tomographic pulmonary angiography (DECTPA) in revealing vasculopathy in coronavirus disease 2019 (COVID-19) has not been fully explored. PURPOSE To evaluate the relationship between DECTPA and disease duration, right ventricular dysfunction (RVD), lung compliance, D-dimer and obstruction index in COVID-19 pneumonia. MATERIALS AND METHODS This institutional review board approved this retrospective study, and waived the informed consent requirement. Between March-May 2020, 27 consecutive ventilated patients with severe COVID-19 pneumonia underwent DECTPA to diagnose pulmonary thrombus (PT); 11 underwent surveillance DECTPA 14 ±11.6 days later. Qualitative and quantitative analysis of perfused blood volume (PBV) maps recorded: i) perfusion defect 'pattern' (wedge-shaped, mottled or amorphous), ii) presence of PT and CT obstruction index (CTOI) and iii) PBV relative to pulmonary artery enhancement (PBV/PAenh); PBV/PAenh was also compared with seven healthy volunteers and correlated with D-Dimer and CTOI. RESULTS Amorphous (n=21), mottled (n=4), and wedge-shaped (n=2) perfusion defects were observed (M=20; mean age=56 ±8.7 years). Mean extent of perfusion defects=36.1%±17.2. Acute PT was present in 11/27(40.7%) patients. Only wedge-shaped defects corresponded with PT (2/27, 7.4%). Mean CTOI was 2.6±5.4 out of 40. PBV/PAenh (18.2 ±4.2%) was lower than in healthy volunteers (27 ±13.9%, p = 0.002). PBV/PAenh correlated with disease duration (β = 0.13, p = 0.04), and inversely correlated with RVD (β = -7.2, p = 0.001), persisting after controlling for confounders. There were no linkages between PBV/PAenh and D-dimer or CTOI. CONCLUSION Perfusion defects and decreased PBV/PAenh are prevalent in severe COVID-19 pneumonia. PBV/PAenh correlates with disease duration and inversely correlates with RVD. PBV/PAenh may be an important marker of vasculopathy in severe COVID-19 pneumonia even in the absence of arterial thrombus.
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Affiliation(s)
| | | | - Nidhish Jeyin
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Ciara Mahon
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Dione L Lother
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Saeed Mirsadraee
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Tom Semple
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Susanna Price
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Caroline Bleakley
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Deepa J Arachchillage
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Elizabeth Shaw
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Brijesh V Patel
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Simon PG Padley
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
| | - Anand Devaraj
- From the Department of Imaging, Royal Brompton Hospital, London, UK (C.A.R., S.R.D., C.M., D.L.L., S.M., T.S., E.S., S.P.P, A.D.); Imperial College London, London, UK (N.J.); Anaesthesia and Critical Care, Royal Brompton Hospital, London, UK (S.P., C.B., B.V.P.); Department of Haematology, Imperial College London, London, UK and Department of Haematology, Royal Brompton Hospital, London, UK (D.J.A)
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Hare SS, Rodrigues JCL, Nair A, Jacob J, Upile S, Johnstone A, Mcstay R, Edey A, Robinson G. The continuing evolution of COVID-19 imaging pathways in the UK: a British Society of Thoracic Imaging expert reference group update. Clin Radiol 2020; 75:399-404. [PMID: 32321645 PMCID: PMC7158776 DOI: 10.1016/j.crad.2020.04.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 04/09/2020] [Indexed: 02/07/2023]
Affiliation(s)
- S S Hare
- Department of Radiology, Royal Free London NHS Trust, London, Pond Street, London NW3 2QJ, UK
| | - J C L Rodrigues
- Department of Radiology, Royal United Hospitals Bath NHS Foundation Trust, Combe Park, Bath BA1 3NG, UK
| | - A Nair
- Department of Radiology, University College London Hospital, 235 Euston Road, London NW1 2BU, UK
| | - J Jacob
- Department of Respiratory Medicine, University College London, London, NW1 2BU, UK; Centre for Medical Image Computing, University College London, London NW1 2BU, UK
| | - S Upile
- Department of Radiology, Salford Royal Hospital, Salford, M6 8HD
| | - A Johnstone
- Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, UK
| | - R Mcstay
- Department of Radiology, Freeman Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Freeman Road, Newcastle upon Tyne, NE7 7DN, UK
| | - A Edey
- Department of Radiology, Southmead Hospital, North Bristol NHS Trust, Southmead Road, Bristol BS10 5NB, UK
| | - G Robinson
- Department of Radiology, Royal United Hospitals Bath NHS Foundation Trust, Combe Park, Bath BA1 3NG, UK.
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Cronin JN, Borges JB, Crockett DC, Farmery AD, Hedenstierna G, Larsson A, Tran MC, Camporota L, Formenti F. Dynamic single-slice CT estimates whole-lung dual-energy CT variables in pigs with and without experimental lung injury. Intensive Care Med Exp 2019; 7:59. [PMID: 31676929 PMCID: PMC6825104 DOI: 10.1186/s40635-019-0273-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/01/2019] [Indexed: 11/23/2022] Open
Abstract
Background Dynamic single-slice CT (dCT) is increasingly used to examine the intra-tidal, physiological variation in aeration and lung density in experimental lung injury. The ability of dCT to predict whole-lung values is unclear, especially for dual-energy CT (DECT) variables. Additionally, the effect of inspiration-related lung movement on CT variables has not yet been quantified. Methods Eight domestic pigs were studied under general anaesthesia, including four following saline-lavage surfactant depletion (lung injury model). DECT, dCT and whole-lung images were collected at 12 ventilatory settings. Whole-lung single energy scans images were collected during expiratory and inspiratory apnoeas at positive end-expiratory pressures from 0 to 20 cmH2O. Means and distributions of CT variables were calculated for both dCT and whole-lung images. The cranio-caudal displacement of the anatomical slice was measured from whole-lung images. Results Mean CT density and volume fractions of soft tissue, gas, iodinated blood, atelectasis, poor aeration, normal aeration and overdistension correlated between dCT and the whole lung (r2 0.75–0.94) with agreement between CT density distributions (r 0.89–0.97). Inspiration increased the matching between dCT and whole-lung values and was associated with a movement of 32% (SD 15%) of the imaged slice out of the scanner field-of-view. This effect introduced an artefactual increase in dCT mean CT density during inspiration, opposite to that caused by the underlying physiology. Conclusions Overall, dCT closely approximates whole-lung aeration and density. This approximation is improved by inspiration where a decrease in CT density and atelectasis can be interpreted as physiological rather than artefactual.
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Affiliation(s)
- John N Cronin
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
| | - João Batista Borges
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
| | | | - Andrew D Farmery
- Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK
| | - Göran Hedenstierna
- Hedenstierna Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Anders Larsson
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Minh C Tran
- Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK
| | - Luigi Camporota
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK.,Department of Adult Critical Care, St. Thomas' Hospital, Guy's and St. Thomas' NHS Foundation Trust, King's Health Partners, London, UK
| | - Federico Formenti
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK. .,Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK.
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Zucker EJ, Kino A, Schmiedeskamp H, Hinostroza V, Fleischmann D, Chan FP. Feasibility and utility of dual-energy chest CTA for preoperative planning in pediatric pulmonary artery reconstruction. Int J Cardiovasc Imaging 2019; 35:1473-1481. [PMID: 31016501 DOI: 10.1007/s10554-019-01602-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 04/09/2019] [Indexed: 01/26/2023]
Abstract
The purpose of this study was to assess in pediatric pulmonary artery (PA) reconstruction candidates the feasibility and added utility of preoperative chest computed tomography angiography (CTA) using dual-energy technique, from which perfused blood volume (PBV)/iodine maps can be generated as a surrogate of pulmonary perfusion. Pediatric PA reconstruction patients were prospectively recruited for a new dose-neutral dual-energy CTA protocol. For each case, the severity of anatomic PA obstruction was graded by two pediatric cardiovascular radiologists in consensus using a modified Qanadli index. PBV maps were qualitatively reviewed and auto-segmented using Siemens syngo.via software. Associations between Qanadli scores and PBV were assessed with Spearman correlation (r) and ROC analysis. Effective radiation doses were estimated from dose-length product and ICRP 103 k-factors, using cubic Hermite spline interpolation. 19 patients were recruited with mean (SD) age of 6.0 (5.1), 11 (57.9%) female, 11 (73.7%) anesthetized. Higher QS correlated with lower PBV, both on a whole lung (r = - 0.54, p < 0.001) and lobar (r = - 0.50, p < 0.001) basis. The lung with lowest absolute PBV was predictive of the lung with highest Qanadli score, with AUC of 0.70 (95% CI 0.47-0.93). Qualitatively, PBV maps were heterogeneous, corresponding to multifocal PA stenoses, with decreased iodine content in areas of most severe obstruction. In conclusion, dual-energy chest CTA is feasible for pediatric PA reconstruction candidates. PBV maps show deficits in regions of more severe anatomic obstruction and may serve as a novel biomarker in this population.
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Affiliation(s)
- Evan J Zucker
- Department of Radiology, Stanford University School of Medicine, 725 Welch Road, Stanford, CA, 94305, USA.
| | - Aya Kino
- Department of Radiology, Stanford University School of Medicine, 725 Welch Road, Stanford, CA, 94305, USA
| | - Heiko Schmiedeskamp
- Siemens Medical Solutions USA, 40 Liberty Boulevard, Malvern, PA, 19355, USA
| | - Virginia Hinostroza
- Department of Radiology, Stanford University School of Medicine, 725 Welch Road, Stanford, CA, 94305, USA
| | - Dominik Fleischmann
- Department of Radiology, Stanford University School of Medicine, 725 Welch Road, Stanford, CA, 94305, USA
| | - Frandics P Chan
- Department of Radiology, Stanford University School of Medicine, 725 Welch Road, Stanford, CA, 94305, USA
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