Clinical use of oxygen‐enhanced T₁ mapping MRI of the lung: Reproducibility and impact of closed versus loose fit oxygen delivery system

Abstract

Oxygen-enhanced T1 mapping MRI produces reproducible data when using a full closed face mask.

Influence of age and sex on the longitudinal relaxation time, T1, of the lung in healthy never‐smokers

“…The average T1 at end tidal inspiration in this study was 1185 ms (16 male, 14 females, mean age 38, TE = 0.67 ms) which is well in line with the mean lung T1 reported in earlier publications by Stadler: 1199 ms (8 male, 2 female, mean age 30, end‐inspiration, TE = 1.4 ms); Alamidi: 1053 ms (8 male, 4 female, mean age 63, TE = 3 ms, free breathing, spin echo); and Renne: 1250 ms (7 male, 5 female, mean age 28, TE 0.8, end‐inspiration) …”

Noninvasive Quantification of Airway Inflammation Following Segmental Allergen Challenge with Functional MR Imaging: A Proof of Concept Study

“…However, with the presented technique based on higher-spatial-resolution images for vessel detection, sufficient accuracy should be reached. In previous work, it has been shown that T1 time determination for the lungs is reproducible using this technique (23). Furthermore, statistical power is limited, because of the relatively small number of patients, and studies with more patients are needed to underline the presented findings.…”

“…Three to four coronal sections covering the challenged segments were acquired in a single breath hold each. The subjects were instructed to breathe normally and stop breathing at the end of a normal inspiration (23). T1 maps were obtained while the patient was breathing room air and again while the patient was breathing 100% oxygen administered by using a standard face mask with a reservoir of 2 L (Adult Non Re-Breather Mask; Mallinkrodt Covidien, Mansfield, Mass) (24).…”

“…For identification of segmental arteries, coronal images were acquired by using a true fast imaging with steady-state precession sequence: 412/1.16; flip angle, 70°; acquisition matrix, 256 3 256; field of view, 45 3 45 cm; section thickness, 4 mm; gap, 2 mm. T1 Map Generation and Segmentation T1 maps were generated as previously described (22,23): Registration of the individual magnitude images obtained at 100% oxygen onto room air images was performed by using a nonrigid registration algorithm (Advanced Normalization Tools; http://stnava.github.io/ ANTs/ [25]). Afterward T1 maps were calculated from the magnitude images by using a nonlinear fit (26) within a self-developed Matlab script (MatLab 2012a, MathWorks, Natick, Mass).…”

Functional imaging of the lungs with gas agents

“…Both respiratory and cardiac triggering have been implemented successfully for 2D OE‐MRI . Typically, nonrebreather facemasks are used with a constant flow of oxygen at 15 L/min . Even with the use of respiratory gating or triggering, lung volume can vary with changes in the fraction of inhaled O 2 .…”