RATIONALE AND OBJECTIVES: To investigate immobilization-induced ventilation defects when performing hyperpolarized (3)He (H(3)He) magnetic resonance imaging (MRI) of the lung. METHODS AND MATERIALS: Twelve healthy subjects underwent MRI of the lungs after inhalation of H(3)He gas at three time points: 1) immediately after having been positioned supine on the MRI scanner table, 2) at 45 minutes while remaining supine, 3) and immediately thereafter after having turned prone. All image sets were reviewed in random order by three independent, blinded readers who recorded number, location, and size of H(3)He ventilation defects. Scores were averaged for each time point and comparisons were made to determine change in number, location, and size of ventilation defects with time and positioning of the subject in the scanner. RESULTS: At baseline supine, there were small numbers of defects in the dependent (posterior) and nondependent (anterior) portions of the lung (P = .625). At 45 minutes, there was a significant increase in the mean number of ventilation defects/slice (VDS) for the dependent (P = .005) and a decrease for the nondependent lung portions (P = .021). After subjects turned prone, mean VDS for posterior defects decreased significantly (P = .011), whereas those for anterior defects increased (P = .010). Most defects were less than 3 cm in diameter. CONCLUSION: It was found that immobilization of the subject for an extended period led to increased number of H(3)He ventilation defects in the dependent portions of the lung. Therefore, after a subject is positioned in the scanner, H(3)He MR imaging should be performed quickly to avoid the occurrence of the immobilization-induced ventilation defects and possible overestimation of disease.
RATIONALE AND OBJECTIVES: To investigate immobilization-induced ventilation defects when performing hyperpolarized (3)He (H(3)He) magnetic resonance imaging (MRI) of the lung. METHODS AND MATERIALS: Twelve healthy subjects underwent MRI of the lungs after inhalation of H(3)He gas at three time points: 1) immediately after having been positioned supine on the MRI scanner table, 2) at 45 minutes while remaining supine, 3) and immediately thereafter after having turned prone. All image sets were reviewed in random order by three independent, blinded readers who recorded number, location, and size of H(3)He ventilation defects. Scores were averaged for each time point and comparisons were made to determine change in number, location, and size of ventilation defects with time and positioning of the subject in the scanner. RESULTS: At baseline supine, there were small numbers of defects in the dependent (posterior) and nondependent (anterior) portions of the lung (P = .625). At 45 minutes, there was a significant increase in the mean number of ventilation defects/slice (VDS) for the dependent (P = .005) and a decrease for the nondependent lung portions (P = .021). After subjects turned prone, mean VDS for posterior defects decreased significantly (P = .011), whereas those for anterior defects increased (P = .010). Most defects were less than 3 cm in diameter. CONCLUSION: It was found that immobilization of the subject for an extended period led to increased number of H(3)He ventilation defects in the dependent portions of the lung. Therefore, after a subject is positioned in the scanner, H(3)He MR imaging should be performed quickly to avoid the occurrence of the immobilization-induced ventilation defects and possible overestimation of disease.
Authors: T A Altes; P L Powers; J Knight-Scott; G Rakes; T A Platts-Mills; E E de Lange; B A Alford; J P Mugler; J R Brookeman Journal: J Magn Reson Imaging Date: 2001-03 Impact factor: 4.813
Authors: Stanislao Fichele; Neil Woodhouse; Andrew J Swift; Zead Said; Martyn N J Paley; Larry Kasuboski; Gary H Mills; Edwin J R van Beek; Jim M Wild Journal: J Magn Reson Imaging Date: 2004-08 Impact factor: 4.813
Authors: Edwin J R van Beek; Jim M Wild; Hans-Ulrich Kauczor; Wolfgang Schreiber; John P Mugler; Eduard E de Lange Journal: J Magn Reson Imaging Date: 2004-10 Impact factor: 4.813
Authors: Eduard E de Lange; Talissa A Altes; James T Patrie; John D Gaare; Jeffrey J Knake; John P Mugler; Thomas A Platts-Mills Journal: Chest Date: 2006-10 Impact factor: 9.410
Authors: Gerardo Tusman; Stephan H Böhm; Alejandro Tempra; Fernando Melkun; Eduardo García; Elsio Turchetto; Paul G H Mulder; Burkhard Lachmann Journal: Anesthesiology Date: 2003-01 Impact factor: 7.892