Anatomical Phase Extraction (APE) Method: A Novel Method to Correct Detrimental Effects of Tissue-Inhomogeneity in Referenceless MR Thermometry - Preliminary Ex Vivo Investigation
Journal
Computational and Mathematical Methods in Medicine
Journal Volume
2021
Date Issued
2021
Author(s)
Abstract
Purpose. We present a novel background tissue phase removing method, called anatomical phase extraction (APE), and to investigate the accuracy of temperature estimation and capability of reducing background artifacts compared with the conventional referenceless methods. Methods. Susceptibility variance was acquired by subtracting pretreatment baseline images taken at different locations (nine pretreatment baselines are acquired and called ?1 to ?9). The susceptibility phase data ?S was obtained using the Wiener deconvolution algorithm. The background phase data ?T was isolated by subtracting ?S from the whole phase data. Finally, ?T was subtracted from the whole phase data before applying the referenceless method. As a proof of concept, the proposed APE method was performed on ex vivo pork tenderloin and compared with other two referenceless temperature estimation approaches, including reweighted ?1 referenceless (RW- ?1) and ?2 referenceless methods. The proposed APE method was performed with four different baselines combination, namely, (?1, ?5, ?2, ?4), (?3, ?5, ?2, ?6), (?7, ?5, ?8, ?4), and (?9, ?5, ?8, ?6), and called APE experiment 1 to 4, respectively. The multibaseline method was used as a standard reference. The mean absolute error (MAE) and two-sample t-test analysis in temperature estimation of three regions of interest (ROI) between the multibaseline method and the other three methods, i.e., APE, RW- ?1, and ?2, were calculated and compared. Results. Our results show that the mean temperature errors of the APE method-experiment 1, APE method-experiment 2, APE method-experiment 3, APE method-experiment 4, and RW- ?1 and ?2 referenceless method are 1.02°C, 1.04°C, 1.00°C, 1.00°C, 4.75°C, and 13.65°C, respectively. The MAEs of the RW- ?1 and ?2 referenceless methods were higher than that of APE method. The APE method showed no significant difference (p>0.05), compared with the multibaseline method. Conclusion. The present work demonstrates the use of the APE method on referenceless MR thermometry to improve the accuracy of temperature estimation during MRI guided high-intensity focused ultrasound for ablation treatment. ? 2021 Chien-Feng Judith Huang et al.
Subjects
Deconvolution
Extraction
Thermometers
Tissue
Deconvolution algorithm
High intensity focused ultrasound
Mean absolute error
Proof of concept
Regions of interest
Temperature estimation
Tissue inhomogeneity
Two sample t tests
Temperature distribution
ablation therapy
article
artifact
controlled study
deconvolution algorithm
ex vivo study
extraction
human
human tissue
intermethod comparison
magnetic resonance guided high intensity focused ultrasound
magnetic resonance thermometry
pork
proof of concept
algorithm
animal
biology
computer assisted diagnosis
imaging phantom
in vitro study
nuclear magnetic resonance imaging
pig
procedures
temperature
thermography
thermometry
thermotherapy
ultrasound surgery
ultrasound therapy
Algorithms
Animals
Computational Biology
Humans
Hyperthermia, Induced
Image Interpretation, Computer-Assisted
In Vitro Techniques
Magnetic Resonance Imaging
Phantoms, Imaging
Sus scrofa
Temperature
Thermography
Thermometry
Ultrasonic Surgical Procedures
Ultrasonic Therapy
Type
journal article