Continuous thermodilution to assess absolute flow and microvascular resistance: validation in humans using [15O]H2O positron emission tomography

2019 ◽  
Vol 40 (28) ◽  
pp. 2350-2359 ◽  
Author(s):  
Henk Everaars ◽  
Guus A de Waard ◽  
Stefan P Schumacher ◽  
Frederik M Zimmermann ◽  
Michiel J Bom ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Coronary Flow ◽  
Emission Tomography ◽  
Flow Measurements ◽  
Left Circumflex Artery ◽  
Intracoronary Infusion ◽  
Positron Emission ◽  
Absolute Flow ◽  
Microvascular Resistance ◽  
Good Agreement

Abstract Aims Continuous thermodilution is a novel technique to quantify absolute coronary flow and microvascular resistance (MVR). Notably, intracoronary infusion of saline elicits maximal hyperaemia, obviating the need for adenosine. The primary aim of this study was to validate continuous thermodilution in humans by comparing invasive measurements to [15O]H2O positron emission tomography (PET). As a secondary goal, absolute flow and MVR were compared between invasive measurements obtained with and without adenosine. Methods and results Twenty-five patients underwent coronary computed tomography angiography (CCTA), [15O]H2O PET, and invasive assessment. Absolute coronary flow and MVR were measured in the left anterior descending and left circumflex artery using a dedicated infusion catheter and a temperature/pressure sensor-tipped guidewire. Invasive measurements were performed with and without adenosine. In order to compare invasive flow measurements with PET perfusion, subtending myocardial mass of the investigated vessels was derived from CCTA using the Voronoi algorithm. Invasive and non-invasive measurements of adenosine-induced hyperaemic flow and MVR showed strong correlation (r = 0.91; P < 0.001 for flow and r = 0.85; P < 0.001 for MVR) and good agreement [intraclass correlation coefficient (ICC) = 0.90; P < 0.001 for flow and ICC = 0.79; P < 0.001 for MVR]. Absolute flow and MVR also correlated well between measurements with and without adenosine (r = 0.97; P < 0.001 for flow and r = 0.98; P < 0.001 for MVR) and showed good agreement (ICC = 0.96; P < 0.001 for flow and ICC = 0.98; P < 0.001 for MVR). Conclusions Continuous thermodilution is an accurate method to measure absolute coronary flow and MVR, which is evidenced by strong agreement with [15O]H2O PET derived flow and resistance. Absolute flow and MVR correlate highly between invasive measurements obtained with and without adenosine, which confirms that intracoronary infusion of room temperature saline elicits steady-state maximal hyperaemia.

scholarly journals Measurement of Human Cerebral Blood Flow with [15O]Butanol and Positron Emission Tomography

1991 ◽  
Vol 11 (5) ◽  
pp. 707-715 ◽  
Author(s):  
Marc S. Berridge ◽  
Lee P. Adler ◽  
A. Dennis Nelson ◽  
Emily H. Cassidy ◽  
Raymond F. Muzic ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Regional Analysis ◽  
Accurate Method ◽  
Emission Tomography ◽  
Flow Measurements ◽  
Positron Emission ◽  
Permeability Surface ◽  
Area Product ◽  
Significant Underestimation ◽  
Good Agreement

Although H215O is widely used for CBF measurement by positron tomography, it underestimates CBF, especially at elevated flow rates. Several tracers, including butanol, overcome this problem, but the short half-life of 15O provides advantages that cause water to remain the tracer of choice. We report the first use and evaluation of 15O–labeled butanol for CBF measurement. Flow measurements made in a similar fashion with water and butanol at 10-min intervals were compared in normal volunteers under resting and hypercapnic conditions. Regional analysis showed good agreement between the tracers at low flows, and significant underestimation of flow by water relative to butanol in regions of elevated flow. The observed relationship between the tracers and the curve-fitted permeability-surface area product for water (133 ml · 100 g−1 · min−1) follow the known relationship between water and true flow. These observations indicate that [15O]-butanol provided accurate measurements of human regional CBF under conditions of elevated perfusion. We conclude that butanol is a convenient and accurate method for routine CBF determination by positron emission tomography.

scholarly journals Comparison of cerebral blood flow measurement with [15O]-water positron emission tomography and arterial spin labeling magnetic resonance imaging: A systematic review

2016 ◽  
Vol 36 (5) ◽  
pp. 842-861 ◽  
Author(s):  
Audrey P Fan ◽  
Hesamoddin Jahanian ◽  
Samantha J Holdsworth ◽  
Greg Zaharchuk
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Arterial Spin Labeling ◽  
Brain Perfusion ◽  
Spin Labeling ◽  
Emission Tomography ◽  
Flow Measurements ◽  
Arterial Blood ◽  
Positron Emission

Noninvasive imaging of cerebral blood flow provides critical information to understand normal brain physiology as well as to identify and manage patients with neurological disorders. To date, the reference standard for cerebral blood flow measurements is considered to be positron emission tomography using injection of the [15O]-water radiotracer. Although [15O]-water has been used to study brain perfusion under normal and pathological conditions, it is not widely used in clinical settings due to the need for an on-site cyclotron, the invasive nature of arterial blood sampling, and experimental complexity. As an alternative, arterial spin labeling is a promising magnetic resonance imaging technique that magnetically labels arterial blood as it flows into the brain to map cerebral blood flow. As arterial spin labeling becomes more widely adopted in research and clinical settings, efforts have sought to standardize the method and validate its cerebral blood flow values against positron emission tomography-based cerebral blood flow measurements. The purpose of this work is to critically review studies that performed both [15O]-water positron emission tomography and arterial spin labeling to measure brain perfusion, with the aim of better understanding the accuracy and reproducibility of arterial spin labeling relative to the positron emission tomography reference standard.

scholarly journals Cerebral Blood Flow Measurements by Magnetic Resonance Imaging Bolus Tracking: Comparison with [15O]H2O Positron Emission Tomography in Humans

1998 ◽  
Vol 18 (9) ◽  
pp. 935-940 ◽  
Author(s):  
Leif Østergaard ◽  
Peter Johannsen ◽  
Peter Høst-Poulsen ◽  
Peter Vestergaard-Poulsen ◽  
Helle Asboe ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Normal Subjects ◽  
Emission Tomography ◽  
Flow Measurements ◽  
Bolus Tracking ◽  
Positron Emission ◽  
Blood Flow Measurements

In six young, healthy volunteers, a novel method to determine cerebral blood flow (CBF) using magnetic resonance (MR) bolus tracking was compared with [15O]H2O positron emission tomography (PET). The method yielded parametric CBF images with tissue contrast in good agreement with parametric PET CBF images. Introducing a common conversion factor, MR CBF values could be converted into absolute flow rates, allowing comparison of CBF values among normal subjects.

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