An image acquisition and registration strategy for the fusion of hyperpolarized helium-3 MRI and x-ray CT images of the lung.
The purpose of this ethics committee approved prospective study was to evaluate an image acquisition and registration protocol for hyperpolarized helium-3 magnetic resonance imaging ((3)He-MRI) and x-ray computed tomography. Nine patients with non-small cell lung cancer (NSCLC) gave written informed consent to undergo a free-breathing CT, an inspiration breath-hold CT and a 3D ventilation (3)He-MRI in CT position using an elliptical birdcage radiofrequency (RF) body coil. (3)He-MRI to CT image fusion was performed using a rigid registration algorithm which was assessed by two observers using anatomical landmarks and a percentage volume overlap coefficient. Registration of (3)He-MRI to breath-hold CT was more accurate than to free-breathing CT; overlap 82.9 +/- 4.2% versus 59.8 +/- 9.0% (p < 0.001) and mean landmark error 0.75 +/- 0.24 cm versus 1.25 +/- 0.60 cm (p = 0.002). Image registration is significantly improved by using an imaging protocol that enables both (3)He-MRI and CT to be acquired with similar breath holds and body position through the use of a birdcage (3)He-MRI body RF coil and an inspiration breath-hold CT. Fusion of (3)He-MRI to CT may be useful for the assessment of patients with lung diseases.
Academic Units of Radiology and Clinical Oncology, University of Sheffield, Sheffield, UK. r.ireland@sheffield.ac.uk
Rob H
RH
Ireland
Neil
N
Woodhouse
Nigel
N
Hoggard
James A
JA
Swinscoe
Bernadette H
BH
Foran
Matthew Q
MQ
Hatton
Jim M
JM
Wild
D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000532:radiotherapy; D006371:Helium; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007554:Isotopes; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D011880:Radiotherapy Planning, Computer-Assisted; D012119:Respiration; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D007554:Isotopes; D006371:Helium