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Patient‐Adaptive Magnetic Resonance Oximetry: Comparison With Invasive Catheter Measurement of Blood Oxygen Saturation in Patients With Cardiovascular Disease
Author(s) -
Varghese Juliet,
Smyke Matthew,
Pan Yue,
Rajpal Saurabh,
Craft Jason,
Potter Lee C.,
Raman Subha V.,
Ahmad Rizwan,
Simonetti Orlando P.
Publication year - 2020
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.27179
Subject(s) - reproducibility , medicine , intraclass correlation , coefficient of variation , oxygen saturation , pulse oximetry , bland–altman plot , nuclear medicine , magnetic resonance imaging , hematocrit , saturation (graph theory) , cardiology , limits of agreement , radiology , anesthesia , oxygen , chemistry , mathematics , organic chemistry , chromatography , combinatorics
Background The current standard method to measure intracardiac oxygen (O 2 ) saturation is by invasive catheterization. Accurate noninvasive blood O 2 saturation by MRI could potentially reduce the duration and risk of invasive diagnostic procedures. Purpose To noninvasively determine blood oxygen saturation in the heart with MRI and compare the accuracy with catheter measurements. Study Type Prospective. Subjects Thirty‐two patients referred for right heart catheterization (RHC) and five healthy subjects. Field Strength/Sequence T2‐prepared single‐shot balanced steady‐state free‐precession at 1.5T. Assessment MR signals in venous and arterial blood, hematocrit, and arterial O 2 saturation from a pulse oximeter were jointly processed to fit the Luz–Meiboom model and estimate blood O 2 saturation in the right heart. Interstudy reproducibility was evaluated in volunteers and patients. Interobserver reproducibility among three readers was assessed using data from volunteers and 10 patients. Accuracy of MR oximetry was compared to RHC in all patients. Statistical Tests Coefficient of variation, intraclass correlation coefficient, Bland–Altman analysis, Pearson's correlation. Results The coefficient of variation for interstudy reproducibility of O 2 saturation was 2.6% on average in volunteers and 3.2% in patients. Interobserver reproducibility among three observers yielded intraclass correlation coefficients of 0.81 and 0.87 respectively for RV and MPA O 2 saturation. O 2 saturation (y = 0.85x + 0.13, R = 0.78) and (a‐v)O 2 difference (y = 0.71x + 0.90, R = 0.69) by MR and RHC were significantly correlated ( N = 32, P < 0.05 in both cases) in patients. MR slightly overestimated O 2 saturation compared to RHC with 2% ± 5% bias and limits of agreement between −7% and 12%. Data Conclusion MR oximetry is repeatable and reproducible. Good agreement was shown between MR and catheter venous O 2 saturation and (a‐v)O 2 difference in a cohort whose venous O 2 ranged from abnormally low to high levels, with most values in the normal physiological range. Level of Evidence 2. Technical Efficacy Stage 2.